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

Abstract

To provide a photosensitive element capable of reducing the number of defects generated in a resist pattern.SOLUTION: A photosensitive element comprises a support film, a barrier layer, and a photosensitive layer in the stated order, wherein the number of particles having a diameter of at least 0.8 μm as measured on the barrier layer-side surface of the support film is at most 100 per 0.0225 mm2.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

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

[0003] The printed wiring board is manufactured, for example, by the following procedure using the above-mentioned photosensitive element. That is, first, the photosensitive layer of the photosensitive element is laminated on a circuit-forming substrate such as a copper-clad laminate. At this time, the surface of the photosensitive layer opposite to the surface in contact with the support film is laminated so as to be in close contact with the surface of the circuit-forming substrate on which the circuit is to be formed. The lamination is performed, for example, by heating and pressing the photosensitive layer onto the circuit-forming substrate (normal pressure lamination method).

[0004] Next, a mask film or the like is used to expose a desired area of ​​the photosensitive layer through the support film to generate radicals. The generated radicals pass through several reaction paths and contribute to a crosslinking reaction (photocuring reaction) of the photopolymerizable compound. Next, after peeling off the support film, the uncured part of the photosensitive layer is dissolved or dispersed and removed with a developer to form a resist pattern. Next, using the resist pattern as a resist, an etching process or a plating process is performed to form a conductor pattern, and finally the photocured part of the photosensitive layer (resist pattern) is peeled off (removed).

[0005] In recent years, with the increasing demand for high-performance semiconductor packages, photosensitive elements capable of forming finer wiring with higher yields are in demand. However, when the photosensitive layer is exposed through a support film as described above, fine defects may occur in the resulting resist pattern, which may cause short circuits in the wiring and reduce the yield.

[0006] Since defects in the resist pattern occur due to scattering of exposed light by particles such as lubricant in the support film, a method of forming an excellent resist pattern by peeling off the support film before exposure and then exposing the photosensitive layer has been considered. However, when the photosensitive layer is exposed after peeling off the support film, the generated radicals come into contact with oxygen in the air, so that the radicals are rapidly stabilized (deactivated), making it difficult for the photocuring reaction of the photopolymerizable compound to proceed. In addition, when a mask is attached to the photosensitive layer during exposure, problems occur such as the photosensitive layer being damaged or contaminated when the mask is peeled off. Therefore, in this method, in order to improve the above problems, the use of a photosensitive element having a resin protective layer (barrier layer) between the support film and the photosensitive layer has been considered (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2013-505483 [Patent Document 2] Special Publication No. 2013-505484 Summary of the Invention [Problem to be solved by the invention]

[0008] However, even when a photosensitive element having a barrier layer between a support film and a photosensitive layer is used, it is not always possible to sufficiently prevent defects from occurring in the obtained resist pattern, and there is room for further improvement.

[0009] The present disclosure has been made in consideration of the problems associated with the above-mentioned conventional techniques, and aims to provide a photosensitive element, a method for forming a resist pattern, and a method for manufacturing a printed wiring board that can reduce the number of defects that occur in a resist pattern. [Means for solving the problem]

[0010] As a result of intensive research to solve the above problems, the present inventors have found that in a photosensitive element having a barrier layer between a photosensitive layer and a support film, traces of particles such as lubricants contained in the support film are left on the surface of the barrier layer, and exposed light is scattered by the unevenness of the traces of these particles, causing defects in the resist pattern. They have also found that the traces of these particles can be reduced by using a support film that satisfies certain conditions, and have completed the present invention.

[0011] That is, the present disclosure provides the following photosensitive element, method for forming a resist pattern, and method for producing a printed wiring board. [1] A photosensitive element comprising a support film, a barrier layer, and a photosensitive layer in this order, wherein the number of particles having a diameter of 0.8 μm or more measured on the surface of the support film on the barrier layer side is 0.0225 mm 2 100 or less per photosensitive element. [2] The number of particles with a diameter of 0.8 μm or more measured on the surface of the barrier layer side of the support film is 0.0225 mm 2 The photosensitive element according to [1] above, wherein the number of the particles per one molecule is 5 or more. [3] The photosensitive element according to the above [1] or [2], wherein the support film has a linear expansion coefficient in the TD direction at 80 to 110° C. of 30 ppm / K or more. [4] The photosensitive element according to [3] above, wherein the support film has a linear expansion coefficient in the TD direction at 80 to 110° C. of 170 ppm / K or less. [5] The photosensitive element according to any one of the above [1] to [4], wherein the barrier layer contains a water-soluble resin. [6] The photosensitive element according to any one of the above [1] to [5], wherein the barrier layer has a thickness of 2 to 12 μm. [7] The number of particles with a diameter of 5.0 μm or more measured on the surface of the barrier layer side of the support film is 0.0225 mm 2 The photosensitive element according to any one of the above [1] to [6], wherein the number of particles per unit area is 0. [8] A method for forming a resist pattern, comprising the steps of: using the photosensitive element according to any one of [1] to [7] above, arranging a photosensitive layer, a barrier layer, and a support film in this order on a substrate from the substrate side; removing the support film and exposing the photosensitive layer to actinic radiation through the barrier layer; and removing an uncured portion of the photosensitive layer and the barrier layer from the substrate. [9] A method for producing a printed wiring board, comprising the step of etching or plating a substrate on which a resist pattern has been formed by the method for forming a resist pattern according to the above item [8] to form a conductor pattern. Effect of the Invention

[0012] According to the present disclosure, it is possible to provide a photosensitive element, a method for forming a resist pattern, and a method for producing a printed wiring board, which are capable of reducing the number of defects that occur in a resist pattern. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating one embodiment of a photosensitive element of the present disclosure. [Diagram 2] 1A to 1C are diagrams illustrating an example of a manufacturing process for a printed wiring board by a semi-additive method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the drawings as necessary. In the following embodiments, it goes without saying that the components (including element steps, etc.) are not necessarily essential unless otherwise specified or considered to be obviously essential in principle. The same applies to the numerical values ​​and ranges, and should not be interpreted as unduly limiting the present disclosure.

[0015] In this specification, (meth)acrylic acid means at least one of acrylic acid and the corresponding methacrylic acid. The same applies to other similar expressions such as (meth)acrylate. Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. When a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0016] In addition, in this specification, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved.

[0017] Furthermore, in this specification, a numerical range indicated using "~" indicates a range including the numerical values ​​described before and after "~" as the minimum and maximum values, respectively. In addition, in a numerical range described in stages in this specification, the upper limit or lower limit of a numerical range of a certain stage may be replaced with the upper limit or lower limit of a numerical range of another stage. In addition, in a numerical range described in this specification, the upper limit or lower limit of the numerical range may be replaced with a value shown in an example. In addition, in this specification, the term "layer" includes a structure having a shape formed on the entire surface as well as a structure having a shape formed on a part of the surface when observed in a plan view.

[0018] [Photosensitive element] 1, the photosensitive element 1 of this embodiment includes a support film 2, a barrier layer 3, and a photosensitive layer 4 in this order, and may further include other layers such as a protective layer 5. In addition, the number of particles having a diameter of 0.8 μm or more measured on the surface F1 of the support film 2 on the barrier layer 3 side is 0.0225 mm 2 Each layer in the photosensitive element according to this embodiment is described in detail below.

[0019] <Support film> Examples of the support film of the present embodiment include polyester films such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene-2,6-naphthalate (PEN), and polyolefin films such as polypropylene and polyethylene. Among them, polyester films may be used. By using a polyester film as the support film, the mechanical strength and heat resistance of the support film tend to be improved. In addition, by using a polyester film, defects such as wrinkles in the barrier layer that occur when forming a barrier layer on the support film tend to be suppressed, and workability tends to be improved. In addition, from the viewpoint of improving the slipperiness and winding property, a polyester film containing particles (lubricant, etc.) may be used. When using a polyester film containing particles (lubricant, etc.), a barrier layer may be formed on the surface having the particles (lubricant, etc.). As such a polyester film, for example, a polyester film into which particles (lubricant, etc.) are kneaded, a polyester film having a layer containing particles (lubricant, etc.) formed on both sides, or a polyester film having a layer containing particles (lubricant, etc.) formed on one side may be used. The support film may be a single layer or a multilayer.

[0020] Methods for adding particles such as a lubricant to a support film include, for example, a method of kneading particles (lubricant, etc.) into the support film, and a method of forming a layer containing particles (lubricant, etc.) on the support film using a known method such as roll coating, flow coating, spray coating, curtain flow coating, dip coating, or slit die coating.

[0021] The number of particles (lubricants, etc.) with a diameter of 0.8 μm or more measured on the surface F1 of the support film on which the barrier layer is to be formed is 0.0225 mm 2 The number of particles is 100 or less per unit area. By using a support film that satisfies the above conditions, it is possible to suppress traces of particles contained in the support film from being left on the barrier layer surface, and the number of defects occurring in the resist pattern can be reduced. In addition, by using a support film that satisfies the above conditions, it is possible to reduce the LER (Line Edge Roughness) of the resist pattern. The number of the particles may be 85 or less, 70 or less, 50 or less, 30 or less, or 20 or less, from the viewpoint of further reducing the number of defects occurring in the resist pattern and further reducing the LER. The lower limit of the number of the particles is not particularly limited, and may be 0, 5 or more, or 10 or more. A support film that satisfies the above condition of the number of particles can be obtained by adjusting the particle size and amount of particles (lubricant, etc.) contained in the support film, or by forming the support film into a multilayer structure and adjusting the presence or absence of particles in each layer, the particle size and content of the particles, and the thickness of each layer. The number of particles (lubricant, etc.) having a diameter of less than 0.8 μm measured on the surface F1 of the support film is not particularly limited.

[0022] 0.0225 mm of particles (lubricants, etc.) with a diameter of 0.8 μm or more measured on the surface F1 on which the barrier layer is formed 2 The number of hits can be measured, for example, using a laser microscope under the following conditions. Note that the measuring device is not limited to the following.

[0023] -Measurement conditions- Equipment: Hybrid laser microscope (manufactured by Lasertec Corporation, product name: OPTELICS HYBRID) Measurement range: 150μm square Measurement details: Acquire a brightness image of the surface F1 of the support film. The acquired brightness image is binarized to measure the particle (lubricant) size and number. 2 ) within the measurement range is calculated.

[0024] The support film is provided with a surface F1 on which the barrier layer is to be formed and a surface opposite to the surface F1, each of which is 0.0225 mm2 or less of particles (such as lubricants) having a diameter of 0.8 μm or more. 2 The number of particles per unit area may vary. The support film has a diameter of 0.8 μm or more (such as lubricants) of 0.0225 mm2 or less measured on the surface opposite to surface F1. 2 The number per unit area may be more than 100. This makes it possible to obtain the effect of the present disclosure of reducing the number of defects occurring in the resist pattern, while further improving the slipperiness and winding property of the support film.

[0025] The number of particles (lubricants, etc.) with a diameter of 5.0 μm or more measured on the surface F1 of the support film on which the barrier layer is formed is 0.0225 mm 2 The number of particles measured on the surface F1 may be 0 per 0.0225 mm 2 By using a support film having 100 or less particles with a diameter of 0.8 μm or more and 0 particles with a diameter of 5.0 μm or more per unit area, it is possible to further suppress traces of particles contained in the support film from being left on the barrier layer surface, and the number of defects occurring in the resist pattern can be further reduced. In addition, by using a support film that satisfies the above conditions, it is possible to further reduce the LER (Line Edge Roughness) of the resist pattern. The support film may be one that does not contain (is not observed to contain) particles (lubricants, etc.) with a diameter of 5.0 μm or more on the surface F1, and may be one that does not contain particles (lubricants, etc.) with a diameter of 5.0 μm or more throughout the entire support film. The number of particles with a diameter of 5.0 μm or more can be measured in the same manner as the number of particles with a diameter of 0.8 μm or more.

[0026] The haze of the support film may be 0.01 to 5.0%, 0.01 to 1.5%, 0.01 to 1.0%, or 0.01 to 0.5%. The haze of the support film may be less than 0.5%. When the haze is 0.01% or more, the support film itself tends to be easily manufactured, and when the haze is 5.0% or less, foreign matter in the photosensitive layer tends to be easily detected when the photosensitive layer of the photosensitive element is formed. Here, "haze" means the degree of cloudiness. The haze in the present disclosure refers to a value measured using a commercially available haze meter (turbidity meter) in accordance with the method specified in JIS K7105. The haze can be measured, for example, using a commercially available turbidity meter such as NDH-5000 (manufactured by Nippon Denshoku Industries Co., Ltd., product name).

[0027] The support film may have a coefficient of linear expansion (CTE) in the transverse direction at 80 to 110 ° C. of 30 ppm / K or more, 40 ppm / K or more, or 45 ppm / K or more, or 170 ppm / K or less, 150 ppm / K or less, or 125 ppm / K or less. If the coefficient of linear expansion is 30 ppm / K or more, when the photosensitive layer is laminated on the substrate together with the support film, the support film and the photosensitive layer are sufficiently deformed, and it is possible to suppress the occurrence of voids between the photosensitive layer and the substrate. The voids cause defects in the resist pattern after the exposure of the photosensitive layer. Therefore, by suppressing the occurrence of the voids, the number of defects occurring in the resist pattern can be further reduced. On the other hand, if the coefficient of linear expansion is 170 ppm / K or less, it is possible to suppress wrinkles occurring during lamination. The coefficient of linear expansion in the transverse direction at 80 to 100 ° C. of the support film can be measured using a thermomechanical analyzer, for example, by the method shown in the examples.

[0028] The thickness of the support film may be 1 to 200 μm, 1 to 100 μm, 1 to 60 μm, 5 to 60 μm, 10 to 60 μm, 10 to 50 μm, 10 to 40 μm, 10 to 30 μm, or 10 to 25 μm. When the thickness of the support film is 1 μm or more, the support film tends to be prevented from being torn when peeled off. In addition, when the thickness of the support film is 200 μm or less, economic benefits tend to be easily obtained.

[0029] <Barrier layer> The photosensitive element of the present embodiment includes a barrier layer between the support film and the photosensitive layer. The barrier layer has an oxygen permeability of 6000 mL / m2 in an environment of 20° C. and 65% RH. 2 ·day·MPa or less (converted value at 25 μm film thickness). The barrier layer may be a layer formed using a resin composition for forming a barrier layer. The resin composition for forming a barrier layer of the present embodiment may contain a water-soluble resin. The barrier layer may be water-soluble and may be soluble in a developer. From the viewpoint of further improving the gas barrier property of the barrier layer, the adhesive strength between the support film and the barrier layer may be smaller than the adhesive strength between the barrier layer and the photosensitive layer. In this case, unintended peeling of the barrier layer and the photosensitive layer can be suppressed when peeling the support film from the photosensitive element.

[0030] (Water-soluble resin) The barrier layer may contain a water-soluble resin. Here, the term "water-soluble resin" refers to a resin having a solubility of 5 g / 100 mL-CH in 100 mL of hexane at 25° C. 14The solubility of the resin is less than 100 mL. This solubility can be calculated by mixing hexane at 25°C with the dried water-soluble resin and checking for the presence or absence of cloudiness. Specifically, prepare sample 1 by putting a mixture of the dried water-soluble resin A(g) and 100 mL of hexane in a colorless transparent glass container with a ground glass stopper, and prepare sample 2 by putting only 100 mL of hexane in the container. Next, shake the sample in the glass container thoroughly and check that the bubbles have disappeared. Immediately after checking, place both containers side by side under diffuse daylight or light equivalent thereto, and compare the state of the liquid of sample 1 with the state of the liquid of sample 2. Compare sample 1 and sample 2, and the amount of addition A(g) at which sample 1 begins to be observed to become cloudier or solids begin to float is regarded as the solubility of the water-soluble resin in 100 mL of hexane at 25°C.

[0031] Examples of the water-soluble resin include polyvinyl alcohol, polyvinylpyrrolidone, and water-soluble polyimides. From the viewpoint of further improving the gas barrier property of the barrier layer and further suppressing deactivation of radicals generated by the actinic rays used for exposure, the water-soluble resin may contain polyvinyl alcohol. Polyvinyl alcohol can be obtained, for example, by saponifying polyvinyl acetate obtained by polymerizing vinyl acetate. The saponification degree of the polyvinyl alcohol used in this embodiment may be 50 mol% or more, 70 mol% or more, or 80 mol% or more. The upper limit of the saponification degree is 100 mol%. By including polyvinyl alcohol having a saponification degree of 50 mol% or more, the gas barrier property of the barrier layer is further improved, and the resolution of the formed resist pattern tends to be further improved. In addition, the "saponification degree" in this specification refers to a value measured in accordance with JIS K 6726 (1994) (Test method for polyvinyl alcohol) specified by the Japanese Industrial Standards.

[0032] The polyvinyl alcohol may be used in combination of two or more kinds having different saponification degrees, viscosities, polymerization degrees, modified species, etc. The average polymerization degree of the polyvinyl alcohol may be 300 to 5000, 300 to 3500, or 300 to 2000. The water-soluble resin may be used alone or in combination of two or more kinds. The water-soluble resin may contain, for example, polyvinyl alcohol and polyvinylpyrrolidone. In this case, the mass ratio of polyvinyl alcohol to polyvinylpyrrolidone (PVA:PVP) may be 40:60 to 90:10, 50:50 to 90:10, or 60:40 to 90:10.

[0033] From the viewpoint of improving gas barrier properties, the content of the water-soluble resin in the resin composition for forming a barrier layer of the present embodiment may be 50 to 300 parts by mass, 60 to 250 parts by mass, 70 to 200 parts by mass, 80 to 150 parts by mass, or 80 to 125 parts by mass relative to 500 parts by mass of water.

[0034] The content of the water-soluble resin in the barrier layer may be 99.0 to 99.95 mass%, 99.3 to 99.9 mass%, or 99.5 to 99.8 mass% based on the total solid content of the barrier layer, from the viewpoints of improving the gas barrier property, improving the peelability between the support film and the barrier layer, and improving the solubility in a developer.

[0035] (Leveling agent) The barrier layer may contain a leveling agent. The leveling agent is oriented on the coating surface to equalize the tension of the coating surface. The leveling agent may be an acrylic polymer, a vinyl-based, a silicone-based, a fluorine-based, or the like. From the viewpoints of transferability to the photosensitive element and solubility in the developer, the leveling agent is preferably an acrylic polymer. From the viewpoints of preventing unintended peeling between the layers while keeping the adhesion between the barrier layer and the support film within an appropriate range and making the adhesive strength between the support film and the barrier layer smaller than the adhesive strength between the barrier layer and the photosensitive layer, and of easily preventing defects from occurring on the barrier layer surface when the barrier layer is formed on the support film (repelling is less likely to occur), the acrylic polymer preferably contains a copolymer having a structural unit derived from at least one selected from the group consisting of butyl (meth)acrylate, isobutyl (meth)acrylate, and methoxy-terminated EO-modified (meth)acrylate, more preferably contains a copolymer having a structural unit derived from butyl (meth)acrylate and isobutyl (meth)acrylate, and even more preferably contains a copolymer having a structural unit derived from butyl (meth)acrylate, isobutyl (meth)acrylate, and methoxy-terminated EO-modified (meth)acrylate.

[0036] The content of each structural unit constituting the acrylic polymer may be, for example, in the following ranges based on the total amount of the structural units. The content of the structural unit derived from butyl (meth)acrylate may be 2 to 20 mass%, 5 to 15 mass%, or 5 to 10 mass%, from the viewpoint of further reducing the number of defects on the barrier layer surface and further suppressing the barrier layer from being damaged when the support film is peeled off. The content of the structural unit derived from isobutyl (meth)acrylate may be 40 to 80 mass%, 50 to 70 mass%, or 55 to 65 mass%, from the viewpoint of further reducing the number of defects on the barrier layer surface and further suppressing the barrier layer from being damaged when the support film is peeled off. The content of the structural unit derived from terminal methoxy group EO-modified (meth)acrylate may be 15 to 45 mass%, 20 to 40 mass%, or 25 to 35 mass%, from the viewpoint of further reducing the number of defects on the barrier layer surface and further suppressing the barrier layer from being damaged when the support film is peeled off. The weight average molecular weight of the acrylic polymer may be 10,000 to 40,000, or 10,000 to 20,000, from the viewpoint of further reducing the number of defects on the surface of the barrier layer and further suppressing damage to the barrier layer when the support film is peeled off.

[0037] The content of the leveling agent in the barrier layer may be 0.05 to 1.0 mass %, 0.1 to 0.7 mass %, or 0.2 to 0.5 mass % based on the total solid content of the barrier layer, from the viewpoint of further reducing the number of defects on the barrier layer surface and further suppressing damage to the barrier layer when the support film is peeled off.

[0038] (UV absorber) The barrier layer may contain an ultraviolet absorbing agent. The ultraviolet absorbing agent (UV absorber) is a compound having a light absorption band in the wavelength range of 300 nm to 400 nm. The ultraviolet absorbing agent may be water-soluble. From the viewpoint of further improving the resolution, the ultraviolet absorbing agent may have a maximum absorption wavelength in the wavelength range of 250 nm to 500 nm. By containing such an ultraviolet absorbing agent, the resolution can be improved.

[0039] The i-line absorptivity of the ultraviolet absorbent may be 5 to 95%, 10 to 90%, or 15 to 75%. The i-line absorptivity can be measured by an ultraviolet-visible spectrophotometer.

[0040] The ultraviolet absorbents may be used alone or in combination of two or more. The solubility of the ultraviolet absorbent in water at 20° C. may be 0.01 g / 100 mL-H2O or more, 0.1 g / 100 mL-H2O or more, or 1 g / 100 mL-H2O or more, from the viewpoint of suppressing aggregation and precipitation of the ultraviolet absorbent in the barrier layer.

[0041] Examples of the ultraviolet absorber include oxybenzophenone compounds, triazole compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, diphenyl acrylate compounds, cyanoacrylate compounds, diphenyl cyanoacrylate compounds, iron or nickel complex salt compounds, etc. Among these, from the viewpoint of further improving the resolution, oxybenzophenone compounds and benzophenone compounds are preferred, benzophenone sulfonic acid compounds are more preferred, and oxybenzophenone sulfonic acid compounds are even more preferred. Note that the "benzophenone sulfonic acid compound" is a compound having a sulfo group in a benzophenone compound, and the benzophenone sulfonic acid compound may be a hydrate. It is speculated that these compounds have a hydrophilic sulfo group in the benzophenone skeleton, which increases the affinity of the benzophenone skeleton with the resist, while the sulfo group increases the affinity with the barrier layer, thereby achieving both resolution and removability of the barrier layer. Among the oxybenzophenone compounds, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid hydrate represented by the following formula (1) is preferred.

[0042] [ka]

[0043] The barrier layer of this embodiment may have an absorbance of 0.01 to 2.0, or 0.1 to 1.0, for light having a wavelength of 365 nm. When the absorbance is 0.01 or more, better resolution tends to be obtained, and when the absorbance is 2.0 or less, the resist pattern shape of the obtained resist pattern tends to be better. The absorbance of the barrier layer can be measured, for example, using a UV spectrophotometer (Hitachi, Ltd., spectrophotometer U-3310). The measurement is performed by placing a laminated film having a barrier layer of any thickness formed on a support film on the measurement side, placing a support film on the reference side, and continuously measuring wavelengths from 300 to 700 nm in absorbance mode, and reading the value at a wavelength of 365 nm.

[0044] (Other Ingredients) The resin composition for forming a barrier layer of the present embodiment may contain alcohols having 3 or more carbon atoms. The alcohols having 3 or more carbon atoms may be monohydric alcohols or polyhydric alcohols (excluding plasticizers of polyhydric alcohol compounds described later). The alcohols having 3 or more carbon atoms may contain at least one selected from the group consisting of compounds represented by the following chemical formulas (2) to (4) and compounds represented by the following general formula (5). By containing these alcohols having 3 or more carbon atoms, the peelability between the barrier layer and the support film can be improved. Therefore, when peeling the support film from the photosensitive element, unintended peeling between the barrier layer and the photosensitive layer can be suppressed, and the deterioration of gas barrier properties and the deterioration of resolution caused by such unintended peeling can be suppressed. [ka] [ka] [ka] [ka]

[0045] In general formula (5), R 11 represents an alkyl group, and R 12 represents an alkylene group. 11 Group and R 12 The sum of the carbon numbers of the R groups is 3 or more. 11 Group and R 12 From the viewpoint of further improving the affinity for water, the sum of the carbon numbers of the R 11 The alkyl group represented by the formula (I) may be an alkyl group having 1 to 4 carbon atoms, and R 12 The alkylene group represented by the formula (5) may be an alkylene group having 1 to 3 carbon atoms. The alcohol having 3 or more carbon atoms represented by the formula (5) may be 2-butoxy-ethanol or 1-methoxy-2-propanol.

[0046] The alcohols having 3 or more carbon atoms may be used alone or in combination of two or more. The solubility of the alcohols having 3 or more carbon atoms in water at 20° C. may be 300 mL / 100 mL-H2O or more, 500 mL / 100 mL-H2O or more, or 1000 mL / 100 mL-H2O or more, from the viewpoint of further suppressing layer separation of the barrier layer.

[0047] In this specification, the "solubility of alcohols having 3 or more carbon atoms in water at 20°C" can be calculated by mixing the alcohols with water at 20°C and checking whether the mixture becomes cloudy. Specifically, a colorless transparent glass container with a ground glass stopper is filled with a mixture of A mL of the alcohols and 100 mL of water to prepare sample 3, and water alone (100 mL) is filled to prepare sample 4. Next, sample 3 and sample 4 in the glass container are thoroughly shaken and mixed, and it is confirmed that the bubbles have disappeared. Immediately after confirmation, both containers are placed side by side under diffuse daylight or light equivalent thereto, and the state of the liquid in sample 3 is compared with the state of the liquid in sample 4. Sample 3 and sample 4 are compared, and the amount A mL of the alcohols added when sample 3 is observed to be more cloudy is defined as the solubility of the alcohols in water at 20°C.

[0048] The content of the alcohol having 3 or more carbon atoms in the resin composition for forming a barrier layer of the present embodiment may be 100 to 500 parts by mass, or 125 to 450 parts by mass, relative to 500 parts by mass of water. When this content is 100 parts by mass or more, the peelability between the formed barrier layer and the support film tends to be improved, and when it is 500 parts by mass or less, the solubility of the water-soluble resin tends to be improved, making it easier to form the barrier layer.

[0049] The content of the alcohol having 3 or more carbon atoms in the barrier layer of the present embodiment may be more than 0 mass% and 2.0 mass% or less, 0.001 to 2.0 mass%, or 0.005 to 1.0 mass% based on the total amount of the barrier layer (the total solid content of the resin composition for forming the barrier layer that forms the barrier layer). A content of 2.0 mass% or less tends to suppress diffusion of the alcohol in a later step, and a content of 0.001 mass% or more tends to improve the peelability between the barrier layer and the support film.

[0050] The resin composition for forming a barrier layer of the present embodiment may contain an alcohol having less than 3 carbon atoms. When the resin composition contains an alcohol having less than 3 carbon atoms, the content of the alcohol may be 125 to 375 parts by mass, or 150 to 325 parts by mass, relative to 500 parts by mass of water. When the content is 125 parts by mass or more, the solubility of the water-soluble resin tends to be improved and the barrier layer tends to be easily formed, and when the content is 375 parts by mass or less, the peelability between the barrier layer and the support film tends to be improved. In addition, the content of the alcohol having less than 3 carbon atoms in the barrier layer of the present embodiment may be 0.1 to 10 mass% (i.e., the amount of the alcohol having less than 3 carbon atoms is 0.1 to 10 parts by mass relative to 100 parts by mass of the total amount of the alcohol having 3 or more carbon atoms) based on the total amount of the alcohol having 3 or more carbon atoms in the barrier layer, from the viewpoint of improving the peelability between the barrier layer and the support film.

[0051] The barrier layer and the resin composition for forming a barrier layer of the present embodiment may contain known additives such as plasticizers, surfactants, etc., to the extent that the effects of the present disclosure are not impaired. Also, the barrier layer and the resin composition for forming a barrier layer of the present embodiment may contain a peeling promoter to the extent that the effects of the present disclosure are not impaired.

[0052] The barrier layer in the photosensitive element of this embodiment can be formed, for example, by applying the barrier layer-forming resin composition of this embodiment onto a support film and drying it. When the barrier layer-forming resin composition contains a leveling agent, when the barrier layer-forming resin composition is applied onto a support film, the leveling agent is likely to be unevenly distributed on the surface side of the support film in the coating. This makes it easy to reduce the surface tension of the barrier layer-forming resin composition and to suppress repelling. In addition, uneven distribution of the leveling agent on the surface side of the support film in the barrier layer makes it easy to reduce the adhesion between the support film and the barrier layer.

[0053] The thickness of the barrier layer is not particularly limited. From the viewpoint of ease of removal of the barrier layer, the thickness of the barrier layer may be 12 μm or less, 10 μm or less, 8 μm or less, 7 μm or less, or 6 μm or less. From the viewpoint of ease of formation of the barrier layer and resolution, the thickness of the barrier layer may be 1.0 μm or more, 1.5 μm or more, 2 μm or more, 3 μm or more, or 4 μm or more. From the viewpoint of suppressing migration of the barrier layer, the thickness of the barrier layer may be 2 μm or more, 3 μm or more, or 4 μm or more.

[0054] <Photosensitive layer> The photosensitive layer of this embodiment is a layer formed using a photosensitive resin composition described later. The photosensitive resin composition can be used according to a desired purpose as long as the properties change when irradiated with light (for example, photocured), and may be either negative type or positive type. The photosensitive resin composition may contain (A) a binder polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator. In addition, it may contain (D) a photosensitizer, (E) a polymerization inhibitor, or other components as necessary. Each component used in the photosensitive resin composition of this embodiment will be described in more detail below.

[0055] ((A) Binder polymer) The (A) binder polymer (hereinafter also referred to as "(A) component") can be produced, for example, by radical polymerization of a polymerizable monomer. Examples of the polymerizable monomer include polymerizable styrene derivatives substituted at the α-position or aromatic ring, such as styrene, vinyltoluene, and α-methylstyrene, acrylamides such as diacetoneacrylamide, acrylonitrile, vinyl alcohol ethers such as vinyl-n-butyl ether, (meth)acrylic acid alkyl esters, (meth)acrylic acid benzyl esters such as benzyl methacrylate, (meth)acrylic acid tetrahydrofurfuryl esters, (meth)acrylic acid dimethylaminoethyl esters, and (meth)acrylic acid diethylaminoethyl esters. Examples of the maleic acid monoesters include esters, (meth)acrylic acid glycidyl esters, 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)acrylic acid, β-styryl (meth)acrylic acid, 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. These may be used alone or in combination of two or more.

[0056] Among these, from the viewpoint of improving plasticity, (meth)acrylic acid alkyl esters may be included. Examples of (meth)acrylic acid alkyl esters include compounds represented by the following general formula (II) and compounds in which the alkyl groups of these compounds are substituted with hydroxyl groups, epoxy groups, halogen groups, etc. H2C=C(R 6 )-COOR 7 (II)

[0057] In general formula (II), R 6 represents a hydrogen atom or a methyl group, R 7R represents an alkyl group having 1 to 12 carbon atoms. 7 Examples of the alkyl group having 1 to 12 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, and structural isomers of these groups.

[0058] Examples of the (meth)acrylic acid alkyl ester represented by the general formula (II) include (meth)acrylic acid methyl ester, (meth)acrylic acid ethyl ester, (meth)acrylic acid propyl ester, (meth)acrylic acid butyl ester, (meth)acrylic acid pentyl ester, (meth)acrylic acid hexyl ester, (meth)acrylic acid heptyl ester, (meth)acrylic acid octyl ester, (meth)acrylic acid 2-ethylhexyl ester, (meth)acrylic acid nonyl ester, (meth)acrylic acid decyl ester, (meth)acrylic acid undecyl ester, (meth)acrylic acid dodecyl ester, etc. These may be used alone or in combination of two or more.

[0059] From the viewpoint of alkaline developability, the component (A) may contain a carboxy group. The component (A) containing a carboxy group can be produced, for example, by radical polymerization of a polymerizable monomer having a carboxy group with another polymerizable monomer. The polymerizable monomer having a carboxy group may be (meth)acrylic acid or methacrylic acid. The acid value of the component (A) containing a carboxy group may be 50 to 250 mgKOH / g, 50 to 200 mgKOH / g, or 100 to 200 mgKOH / g.

[0060] The carboxy group content of component (A) (the blending ratio of polymerizable monomers having a carboxy group to the total amount of polymerizable monomers used in the binder polymer) may be 12 to 50 mass%, 12 to 40 mass%, 15 to 35 mass%, 15 to 30 mass%, or 20 to 30 mass%, from the viewpoint of improving the alkali developability and the alkali resistance in a well-balanced manner. When the carboxy group content is 12 mass% or more, the alkali developability tends to be improved, and when it is 50 mass% or less, the alkali resistance tends to be excellent.

[0061] The content of the structural unit derived from the polymerizable monomer having a carboxy group in the component (A) correlates with the blending ratio of the polymerizable monomer having a carboxy group, and may be 12 to 50 mass%, 12 to 40 mass%, 15 to 35 mass%, 15 to 30 mass%, or 20 to 30 mass%.

[0062] From the viewpoint of adhesion and chemical resistance, the (A) component may use styrene or a styrene derivative as a polymerizable monomer. When the styrene or styrene derivative is used as the polymerizable monomer, its content (the blending ratio of styrene or a styrene derivative to the total amount of polymerizable monomers used in the (A) component) may be 10 to 60 mass%, 15 to 50 mass%, 30 to 50 mass%, 35 to 50 mass%, or 40 to 50 mass% from the viewpoint of further improving adhesion and chemical resistance. When the content is 10 mass% or more, adhesion tends to be improved, and when it is 60 mass% or less, it is possible to suppress the peeled pieces from becoming large during development, and the time required for peeling tends to be suppressed from being prolonged.

[0063] The content of structural units derived from styrene or a styrene derivative in component (A) correlates with the blending ratio of the styrene or styrene derivative, and may be 10 to 60 mass%, 15 to 50 mass%, 30 to 50 mass%, 35 to 50 mass%, or 40 to 50 mass%.

[0064] From the viewpoints of resolution and aspect ratio, the component (A) may use a benzyl (meth)acrylate ester as a polymerizable monomer. From the viewpoints of further improving the resolution and aspect ratio, the content of structural units derived from the benzyl (meth)acrylate ester in the component (A) may be 15 to 50 mass%, 15 to 45 mass%, 15 to 40 mass%, 15 to 35 mass%, or 20 to 30 mass%.

[0065] These binder polymers can be used alone or in combination of two or more. When two or more types are used in combination, examples of the (A) component include two or more binder polymers made of different polymerizable monomers, two or more binder polymers having different weight average molecular weights, and two or more binder polymers having different dispersities.

[0066] The component (A) can be produced by a conventional method, for example, by radical polymerization of an alkyl (meth)acrylate ester, (meth)acrylic acid, styrene, or the like.

[0067] From the viewpoint of improving mechanical strength and alkaline developability in a well-balanced manner, the weight average molecular weight of the (A) component may be 20,000 to 300,000, 40,000 to 150,000, 40,000 to 120,000, or 50,000 to 80,000. When the weight average molecular weight of the (A) component is 20,000 or more, the developer resistance tends to be excellent, and when it is 300,000 or less, the development time tends to be suppressed from being extended. The weight average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) and converted using a calibration curve prepared using standard polystyrene.

[0068] The content of the above component (A) may 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, based on 100 parts by mass of the total solid content of the components (A) and (B), which will be described later. When the content of the component (A) is within this range, the coating properties of the photosensitive resin composition and the strength of the photocured part are improved.

[0069] ((B) Photopolymerizable compound) The photosensitive resin composition according to the present embodiment may contain a photopolymerizable compound (B) (hereinafter, also referred to as "component (B)"). The component (B) may be any compound that is photopolymerizable or photocrosslinkable, and may be, for example, a compound having at least one ethylenically unsaturated bond in the molecule.

[0070] The component (B) may contain a bisphenol type (meth)acrylate compound. Examples of the bisphenol type (meth)acrylate compound include 2,2-bis(4-((meth)acryloxypolyethoxy)phenyl)propane, 2,2-bis(4-((meth)acryloxypolypropoxy)phenyl)propane, and 2,2-bis(4-((meth)acryloxypolyethoxypolypropoxy)phenyl)propane. These may be used alone or in combination of two or more. In addition, the bisphenol type (meth)acrylate compound may contain 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane and 2,2-bis(4-(methacryloxydiethoxy)phenyl)propane.

[0071] Commercially available bisphenol type (meth)acrylate compounds include, for example, 2,2-bis(4-(methacryloxydiethoxy)phenyl)propane ("BPE-200" manufactured by Shin-Nakamura Chemical Co., Ltd.), 2,2-bis(4-(methacryloxypentaethoxy)phenyl)propane ("BPE-500" manufactured by Shin-Nakamura Chemical Co., Ltd. or "FA-321M" manufactured by Showa Denko Materials Inc.), 2,2-bis(4-(methacryloxypentadecaethoxy)phenyl)propane ("BPE-1300" manufactured by Shin-Nakamura Chemical Co., Ltd.), and 2,2-bis(4-(methacryloxypolyethoxy)phenyl)propane ("BP-2EM" manufactured by Kyoeisha Chemical Co., Ltd. (EO group: 2.6 (average value))).

[0072] From the viewpoint of further improving chemical resistance, the content of the bisphenol type (meth)acrylate compound may be 1 to 50 mass%, 3 to 40 mass%, 10 to 40 mass%, 20 to 40 mass%, or 30 to 40 mass% relative to the total solid content of the (A) component and the (B) component.

[0073] Furthermore, from the viewpoint of further improving chemical resistance, the content of the bisphenol type (meth)acrylate compound may be 30 to 99 mass%, 50 to 97 mass%, 60 to 95 mass%, 70 to 95 mass%, or 80 to 90 mass% relative to the total solid content of the (B) component.

[0074] The content of component (B) may be 20 to 70 parts by mass, 25 to 60 parts by mass, or 30 to 50 parts by mass, based on 100 parts by mass of the total solid content of components (A) and (B). When the content of component (B) is within this range, the photosensitive resin composition exhibits improved resolution, adhesion, and suppression of resist tail generation, as well as improved photosensitivity and coatability.

[0075] ((C) Photopolymerization initiator) The photosensitive resin composition according to the present embodiment may contain at least one photopolymerization initiator (C) (hereinafter, also referred to as "component (C)"). There are no particular limitations on the component (C) as long as it can polymerize component (B), and the component (C) can be appropriately selected from commonly used photopolymerization initiators.

[0076] Examples of the component (C) include aromatic ketones such as 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1, quinones such as alkylanthraquinones, benzoin ether compounds such as benzoin alkyl ethers, benzoin compounds such as benzoin and alkylbenzoins, benzyl derivatives such as benzyl dimethyl ketal, 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimers and 2-(o-fluorophenyl)-4,5-diphenylimidazole dimers, and acridine derivatives such as 9-phenylacridine and 1,7-(9,9'-acridinyl)heptane. These can be used alone or in combination of two or more.

[0077] Among these, from the viewpoint of improving resolution, 2,4,5-triarylimidazole dimer may be contained. Examples of the 2,4,5-triarylimidazole dimer include 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-bis-(m-methoxyphenyl)imidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer. Among these, from the viewpoint of improving photosensitivity stability, 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer may be contained.

[0078] As the 2,4,5-triarylimidazole dimer, for example, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole is commercially available as B-CIM (product name, manufactured by Hodogaya Chemical Co., Ltd.).

[0079] From the viewpoints of further improving the photosensitivity and adhesion and further suppressing the light absorption of the component (C), the component (C) may contain at least one kind of 2,4,5-triarylimidazole dimer or may contain 2-(2-chlorophenyl)-4,5-diphenylimidazole dimer. The 2,4,5-triarylimidazole dimer may have a symmetric or asymmetric structure.

[0080] The content of component (C) may be 0.01 to 30 parts by mass, 0.1 to 10 parts by mass, 1 to 7 parts by mass, 1 to 6 parts by mass, 1 to 5 parts by mass, or 2 to 5 parts by mass, based on 100 parts by mass of the total solid content of components (A) and (B). When the content of component (C) is 0.01 part by mass or more, photosensitivity, resolution, and adhesion tend to be improved, and when it is 30 parts by mass or less, the resist pattern shape tends to be excellent.

[0081] ((D) Photosensitizer) The photosensitive resin composition according to the present embodiment may contain a photosensitizer (D) (hereinafter, also referred to as "component (D)"). By containing component (D), it tends to be possible to effectively utilize the absorption wavelength of the actinic ray used for exposure.

[0082] Examples of the (D) component include pyrazolines, dialkylaminobenzophenones, anthracenes, coumarins, acridines, xanthones, oxazoles, benzoxazoles, thiazoles, benzothiazoles, triazoles, stilbenes, triazines, thiophenes, naphthalimides, and triarylamines. These can be used alone or in combination of two or more. From the viewpoint of more effectively utilizing the absorption wavelength of the actinic radiation used for exposure, the (D) component may include pyrazolines, anthracenes, coumarins, acridines, or dialkylaminobenzophenones, and may include coumarins, acridines, or dialkylaminobenzophenones, or may include dialkylaminobenzophenones. Commercially available dialkylaminobenzophenones include, for example, "EAB" manufactured by Hodogaya Chemical Co., Ltd.

[0083] When the (D) component is contained, its content may be 1.0 parts by mass or less, 0.5 parts by mass or less, 0.15 parts by mass or less, 0.12 parts by mass or less, or 0.10 parts by mass or less, based on 100 parts by mass of the total solid content of the (A) component and the (B) component. When the (D) component is 1.0 parts by mass or less, based on 100 parts by mass of the total solid content of the (A) component and the (B) component, the deterioration of the resist pattern shape and the resist tail generation tendency can be suppressed, and the resolution tends to be improved. In addition, the (D) component may be 0.01 parts by mass or more, based on 100 parts by mass of the total solid content of the (A) component and the (B) component, from the viewpoint of easily obtaining high photosensitivity and good resolution.

[0084] ((E) Polymerization inhibitor) The photosensitive resin composition according to the present embodiment may contain (E) a polymerization inhibitor (hereinafter also referred to as "component (E)"). By containing component (E), it tends to be possible to adjust the exposure dose required for photocuring the photosensitive resin composition to an optimal exposure dose for exposure with a projection exposure machine. Examples of component (E) include alkyl catechols such as catechol, resorcinol (resorcin), 1,4-hydroquinone, 2-methylcatechol, 3-methylcatechol, 4-methylcatechol, 2-ethylcatechol, 3-ethylcatechol, 4-ethylcatechol, 2-propylcatechol, 3-propylcatechol, 4-propylcatechol, 2-n-butylcatechol, 3-n-butylcatechol, 4-n-butylcatechol, 2-tert-butylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, and 3,5-di-tert-butylcatechol; Examples of the resorcinol include alkyl resorcinols such as rucinol, 4-methylresorcinol, 5-methylresorcinol (orcinol), 2-ethylresorcinol, 4-ethylresorcinol, 2-propylresorcinol, 4-propylresorcinol, 2-n-butylresorcinol, 4-n-butylresorcinol, 2-tert-butylresorcinol, and 4-tert-butylresorcinol, alkyl hydroquinones such as methylhydroquinone, ethylhydroquinone, propylhydroquinone, tert-butylhydroquinone, and 2,5-di-tert-butylhydroquinone, pyrogallol, and phloroglucinol. These may be used alone or in combination of two or more.

[0085] (Other Ingredients) The photosensitive resin composition according to the present embodiment may contain, as necessary, 0.01 to 20 parts by mass of each of additives such as dyes such as malachite green, Victoria Pure Blue, brilliant green, and methyl violet, photocoloring agents such as tribromophenyl sulfone, leuco crystal violet, diphenylamine, benzylamine, triphenylamine, diethylaniline, and o-chloroaniline, thermal coloring inhibitors, plasticizers such as p-toluenesulfonamide, pigments, fillers, defoamers, flame retardants, adhesion imparting agents, leveling agents, peeling promoters, antioxidants, fragrances, imaging agents, and thermal crosslinking agents, based on 100 parts by mass of the total solid content of the (A) component and the (B) component. These additives may be used alone or in combination of two or more.

[0086] In addition, the photosensitive resin composition according to this embodiment may contain at least one organic solvent as necessary in order to improve the handling property of the photosensitive composition or to adjust the viscosity and storage stability. As the organic solvent, any organic solvent that is commonly used may be used without any particular limitation. Specifically, for example, organic solvents such as methanol, ethanol, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, toluene, N,N-dimethylformamide, propylene glycol monomethyl ether, or mixed solvents thereof may be mentioned. These may be used alone or in combination of two or more.

[0087] <Protective layer> In the photosensitive element of the present embodiment, a protective layer may be laminated on the surface of the photosensitive layer opposite to the surface in contact with the barrier layer. As the protective layer, for example, a polymer film such as polyethylene or polypropylene may be used. In addition, the same polymer film as the support film described above may be used, or a different polymer film may be used.

[0088] A method for producing a photosensitive element in which a support film, a barrier layer, a photosensitive layer and a protective layer are laminated in this order will be described below.

[0089] <Method of manufacturing photosensitive element> First, for example, a water-soluble resin containing polyvinyl alcohol is gradually added to a mixed solvent of water heated to 70 to 90°C and an organic solvent used as needed so that the solid content is 10 to 20% by mass, and stirred for about 1 hour, and then other components such as a leveling agent are mixed and dissolved uniformly as needed to obtain a resin composition for forming a barrier layer. In this specification, the term "solid content" refers to the non-volatile content of the resin composition excluding volatile substances such as water and organic solvents. In other words, it refers to components other than solvents such as water and organic solvents that remain without volatilizing in the drying process, and includes liquid, starch syrup, and wax-like substances at room temperature around 25°C.

[0090] Next, the resin composition for forming a barrier layer is applied onto a support film and dried to form a barrier layer. The resin composition for forming a barrier layer can be applied onto a support film by a known method such as roll coating, comma coating, gravure coating, air knife coating, die coating, bar coating, or spray coating.

[0091] The applied resin composition for forming a barrier layer may be dried for 5 to 30 minutes at 70 to 150° C. without any particular limitation as long as it can remove at least a part of the solvent such as water. After drying, the amount of the solvent remaining in the barrier layer may be 2% by mass or less from the viewpoint of preventing the diffusion of the solvent in the subsequent steps.

[0092] Next, a photosensitive resin composition may be applied on the barrier layer of the support film on which the barrier layer is formed in the same manner as the application of the resin composition for forming a barrier layer, and then dried to form a photosensitive layer on the barrier layer. Next, a protective layer may be laminated on the photosensitive layer thus formed, thereby producing a photosensitive element having a support film, a barrier layer, a photosensitive layer, and a protective layer in this order. In addition, a photosensitive element having a support film, a barrier layer, a photosensitive layer, and a protective layer in this order may be obtained by laminating a support film on which a barrier layer is formed and a protective layer on which a photosensitive layer is formed.

[0093] The thickness of the photosensitive layer in the photosensitive element can be appropriately selected depending on the application, and may be 1 μm or more, 5 μm or more, or 10 μm or more after drying, and may be 200 μm or less, 100 μm or less, 50 μm or less, or less than 20 μm. When the thickness of the photosensitive layer is 1 μm or more, 5 μm or more, or 10 μm or more, industrial coating becomes easy and productivity tends to improve. In addition, when the thickness of the photosensitive layer is 200 μm or less, 100 μm or less, 50 μm or less, or less than 20 μm, the photosensitivity is high and the photocuring property of the bottom of the resist is excellent, so that a resist pattern with excellent resolution and aspect ratio tends to be formed.

[0094] The melt viscosity of the photosensitive layer in the photosensitive element at 110°C can be appropriately selected depending on the type of substrate (undercoat) in contact with the photosensitive layer, and may be 50 to 10,000 Pa·s, 100 to 5,000 Pa·s, or 200 to 1,000 Pa·s at 110°C after drying. When the melt viscosity at 110°C is 50 Pa·s or more, wrinkles and voids do not occur in the lamination process, and productivity tends to improve. Also, when the melt viscosity at 110°C is 10,000 Pa·s or less, adhesion to the undercoat improves in the lamination process, and adhesion defects tend to be reduced.

[0095] The form of the photosensitive element according to the present embodiment is not particularly limited. For example, it may be in the form of a sheet, or may be wound in the form of a roll around a core. When wound in the form of a roll, it may be wound so that the support film is on the outside. Examples of materials for the core include plastics such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, and ABS resin (acrylonitrile-butadiene-styrene copolymer).

[0096] The end faces of the thus obtained rolled photosensitive element roll may be provided with end face separators from the viewpoint of end face protection, or may be provided with moisture-proof end face separators from the viewpoint of edge fusion resistance. As a packaging method, the rolled photosensitive element roll may be packaged in a black sheet with low moisture permeability.

[0097] The photosensitive element according to this embodiment can be suitably used, for example, in the method for forming a resist pattern and the method for producing a printed wiring board, which will be described later.

[0098] [Method of forming resist pattern] The method for forming a resist pattern according to the present embodiment includes: (i) a step of arranging a photosensitive layer, a barrier layer, and a support film on a substrate in this order from the substrate side using the photosensitive element (hereinafter also referred to as "(i) photosensitive layer and barrier layer forming step"); (ii) a step of removing the support film and exposing the photosensitive layer to active light through the barrier layer (hereinafter also referred to as "(ii) exposure step"); and (iii) a step of removing the uncured parts of the barrier layer and the photosensitive layer from the substrate (hereinafter also referred to as "(iii) development step"); and may include other steps as necessary. The resist pattern may be a photocured product pattern of a photosensitive resin composition or a relief pattern. Depending on the purpose, the resist pattern in the present embodiment may be used as a resist or for other purposes such as a protective film.

[0099] (i) Photosensitive layer and barrier layer forming step In the photosensitive layer and barrier layer forming step, the photosensitive layer and barrier layer are formed on a substrate using the photosensitive element. The substrate is not particularly limited, but typically includes a circuit-forming substrate having an insulating layer and a conductor layer formed on the insulating layer, or a die pad (substrate for lead frame) such as an alloy substrate.

[0100] As a method for forming the photosensitive layer and the barrier layer on the substrate, for example, when a photosensitive element having a protective layer is used, the protective layer is removed, and then the photosensitive layer of the photosensitive element is heated and pressed onto the substrate to form the photosensitive layer and the barrier layer on the substrate, thereby obtaining a laminate having the substrate, the photosensitive layer, the barrier layer, and the support film in this order.

[0101] When the photosensitive layer and barrier layer forming step is carried out using a photosensitive element, the step may be carried out under reduced pressure from the viewpoint of adhesion and conformability. Heating during compression may be carried out at a temperature of 70 to 130° C., and compression may be carried out at a pressure of 0.1 to 1.0 MPa (1 to 10 kgf / cm 2 ) pressure, but these conditions can be appropriately selected as necessary. Note that if the photosensitive layer of the photosensitive element is heated to 70 to 130°C, it is not necessary to preheat the substrate in advance, but the substrate can be preheated in order to further improve the adhesion and tracking ability.

[0102] ((ii) Exposure process) In the exposure step, the support film is removed, and the photosensitive layer is exposed to active light through the barrier layer. As a result, the exposed portion irradiated with active light may be photocured to form a photocured portion (latent image), or the unexposed portion not irradiated with active light may be photocured to form a photocured portion. When the photosensitive layer and the barrier layer are formed using the above-mentioned photosensitive element, the support film present on the photosensitive layer is peeled off, and then the layer is exposed. By exposing the photosensitive layer through the barrier layer, a resist pattern with excellent resolution and resist pattern shape can be formed.

[0103] As the exposure method, a known exposure method can be applied, for example, a method of irradiating an active light beam in an image-wise manner through a negative or positive mask pattern called artwork (mask exposure method), an LDI (Laser Direct Imaging) exposure method, or a method of irradiating an active light beam projected from an image of a photomask in an image-wise manner through a lens (projection exposure method), etc. Among them, the projection exposure method may be used from the viewpoint of excellent resolution. That is, the photosensitive element etc. according to this embodiment is applied to the projection exposure method. The projection exposure method can also be said to be an exposure method using an active light beam with attenuated energy.

[0104] The light source of the actinic ray is not particularly limited as long as it is a commonly used known light source, and for example, a carbon arc lamp, a mercury vapor arc lamp, an ultra-high pressure mercury 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, a semiconductor laser such as a gallium nitride blue-violet laser, and the like that effectively emit ultraviolet light are used. In addition, a photographic flood lamp, a sun lamp, and the like that effectively emit visible light may be used. Among these, from the viewpoint of improving the resolution and alignment in a well-balanced manner, a light source that can emit i-line monochromatic light with an exposure wavelength of 365 nm, a light source that can emit h-line monochromatic light with an exposure wavelength of 405 nm, or a light source that can emit actinic ray with an exposure wavelength of IHG may be used, and among them, a light source that can emit i-line monochromatic light with an exposure wavelength of 365 nm may be used. Examples of light sources that can emit i-line monochromatic light with an exposure wavelength of 365 nm include ultra-high pressure mercury lamps.

[0105] ((iii) Development process) In the developing step, the barrier layer and the uncured portion of the photosensitive layer are removed from the substrate. The developing step forms a resist pattern on the substrate, which is made up of a photocured portion of the photosensitive layer. When the barrier layer is water-soluble, the barrier layer may be removed by washing with water, and then the uncured portion other than the photocured portion may be removed by a developer. When the barrier layer is soluble in a developer, the barrier layer may be removed by a developer together with the uncured portion other than the photocured portion. Examples of the developing method include wet development.

[0106] In the case of wet development, a developer corresponding to the photosensitive resin composition can be used to develop the photosensitive resin composition by a known wet development method. Examples of the wet development method include a dip method, a paddle method, a high-pressure spray method, a method using brushing, slapping, scrubbing, and a swinging immersion method, and from the viewpoint of improving the resolution, the high-pressure spray method is the most suitable. These wet development methods may be used alone or in combination of two or more methods.

[0107] The developer is appropriately selected depending on the composition of the photosensitive resin composition, and examples thereof include an alkaline aqueous solution and an organic solvent developer.

[0108] From the viewpoint of safety, stability, and good operability, an alkaline aqueous solution may be used as the developer. Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium, or potassium hydroxide, 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.

[0109] Examples of the alkaline aqueous solution used for development include a dilute solution of 0.1 to 5% by mass of sodium carbonate, a dilute solution of 0.1 to 5% by mass of potassium carbonate, a dilute solution of 0.1 to 5% by mass of sodium hydroxide, and a dilute solution of 0.1 to 5% by mass of sodium tetraborate. The pH of the alkaline aqueous solution used for development may be in the range of 9 to 11, and the temperature of the alkaline aqueous solution can be adjusted according to the developability of the photosensitive layer. The alkaline aqueous solution may contain, for example, a surfactant, an antifoaming agent, and a small amount of an organic solvent for promoting development. Examples of the organic solvent used in the alkaline aqueous solution include 3-acetone alcohol, acetone, ethyl acetate, an alkoxyethanol having an alkoxy group with 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

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

[0111] (Other processes) In the method for forming a resist pattern according to this embodiment, after removing the uncured portion in the development step, heating at 60 to 250° C. or applying a 0.2 to 10 J / cm 2 2 The method may further include a step of hardening the resist pattern by exposure to light at an exposure dose of 1000 nm or more.

[0112] [Manufacturing method for printed wiring boards] The method for producing a printed wiring board according to this embodiment includes a step of forming a conductor pattern by etching or plating a substrate on which a resist pattern has been formed by the above-mentioned method for forming a resist pattern, and may include other steps such as a resist pattern removal step as necessary. The method for producing a printed wiring board according to this embodiment can be suitably used for forming a conductor pattern by using the above-mentioned method for forming a resist pattern using a photosensitive element, and is more suitably applied to a method for forming a conductor pattern by plating. The conductor pattern can also be called a circuit.

[0113] In the etching process, a resist pattern formed on a substrate having a conductor layer is used as a mask to etch away the conductor layer of the substrate that is not covered with resist, thereby forming a conductor pattern.

[0114] The method of etching is appropriately selected depending on the conductor layer to be removed. Examples of the etching solution include a cupric chloride solution, a ferric chloride solution, an alkaline etching solution, a hydrogen peroxide-based etching solution, etc., and a ferric chloride solution may be used because of its good etch factor.

[0115] On the other hand, in plating, a resist pattern formed on a substrate having a conductor layer is used as a mask to plate copper, solder, etc., on the conductor layer of the substrate that is not covered with the resist. After plating, the resist is removed by removing the resist pattern, which will be described later, and the conductor layer that was covered with the resist is further etched to form a conductor pattern.

[0116] The plating method may be either electrolytic plating or electroless plating, and more preferably electroless plating. Examples of electroless plating include copper plating such as copper sulfate plating and copper pyrophosphate plating, solder plating such as high-throw solder plating, nickel plating such as Watts bath (nickel sulfate-nickel chloride) plating and nickel sulfamate plating, and gold plating such as hard gold plating and soft gold plating.

[0117] After the etching or plating process, the resist pattern on the substrate is removed. The resist pattern can be removed, for example, by stripping with an aqueous solution that is more strongly alkaline than the aqueous solution used in the development process. As the aqueous solution of the strong alkali, for example, an aqueous solution of 1 to 10% by mass of sodium hydroxide, an aqueous solution of 1 to 10% by mass of potassium hydroxide, etc. can be used. Among these, an aqueous solution of 1 to 5% by mass of sodium hydroxide or an aqueous solution of potassium hydroxide can be used.

[0118] Methods for removing the resist pattern include, for example, a dipping method and a spray method, which may be used alone or in combination.

[0119] When the resist pattern is removed after the plating process, the conductor layer covered with the resist is etched by an etching process to form a conductor pattern, thereby manufacturing a desired printed wiring board. The method of the etching process is appropriately selected depending on the conductor layer to be removed. For example, the above-mentioned etching solution can be used.

[0120] The method for manufacturing a printed wiring board according to this embodiment can be applied to the manufacture of not only single-layer printed wiring boards but also multi-layer printed wiring boards, and can also be applied to the manufacture of printed wiring boards having small diameter through holes.

[0121] The method for manufacturing a printed wiring board according to this embodiment can be suitably used for manufacturing a high-density package substrate, particularly for manufacturing a wiring board by a semi-additive process. An example of a manufacturing process for a wiring board by a semi-additive process is shown in FIG.

[0122] In FIG. 2(a), a substrate (substrate for forming a circuit) in which a conductor layer 40 is formed on an insulating layer 50 is prepared. The conductor layer 40 is, for example, a copper layer. In FIG. 2(b), a photosensitive layer 30 and a barrier layer 20 are formed on the conductor layer 40 of the substrate by the photosensitive layer and barrier layer forming process. In FIG. 2(c), a photocured portion is formed in the photosensitive layer 30 by irradiating the photosensitive layer 30 with active light 80 projected from an image of a photomask through the barrier layer 20 by the exposure process. In FIG. 2(d), a resist pattern 32, which is a photocured portion, is formed on the substrate by removing the region (including the barrier layer) other than the photocured portion formed by the exposure process by the development process. In FIG. 2(e), a plating layer 60 is formed on the conductor layer 40 of the substrate that is not covered by resist by a plating process using the resist pattern 32, which is a photocured portion, as a mask. In FIG. 2(f), the resist pattern 32, which is the photocured portion, is peeled off with a strong alkaline aqueous solution, and then the conductor layer 40 masked by the resist pattern 32 is removed by flash etching to form the plating layer 62 after etching and the conductor pattern 70 including the conductor layer 42 after etching. The conductor layer 40 and the plating layer 60 may be made of the same material or different materials. When the conductor layer 40 and the plating layer 60 are made of the same material, the conductor layer 40 and the plating layer 60 may be integrated together. Although the projection exposure method is described in FIG. 2, the resist pattern 32 may be formed by using a combination of a mask exposure method and an LDI exposure method.

[0123] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments. EXAMPLES

[0124] Hereinafter, the present disclosure will be described in more detail based on examples, but the present disclosure is not limited to the following examples. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0125] <Synthesis of Binder Polymer A-1> A solution (a) was prepared by mixing 270g of methacrylic acid, 500g of styrene, 200g of benzyl methacrylate, and 30g of 2-hydroxyethyl methacrylate, which are polymerizable monomers, and 9g of azobisisobutyronitrile. A solution (b) was prepared by mixing 1.4g of azobisisobutyronitrile with a mixture of 160g of 1-methoxy-2-propanol and 120g of toluene. A mixture of 450g of 1-methoxy-2-propanol and 380g of toluene was added to a flask equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel, and a nitrogen gas inlet tube, and then the mixture was stirred while blowing nitrogen gas into the flask and heated to 80°C. The solution (a) was added dropwise to the mixture in the flask at a constant dropping rate over 4 hours, and then stirred at 80°C for 2 hours. Next, the solution (b) was added dropwise to the solution in the flask at a constant rate over 10 minutes, and the solution in the flask was stirred at 80°C for 3 hours. The solution in the flask was then heated to 90°C over 30 minutes, and kept at 90°C for 6 hours. The stirring was then stopped and the solution was cooled to room temperature (25°C) to obtain a solution of binder polymer A-1. The non-volatile content (solid content) of the binder polymer A-1 solution was 49% by mass. The weight average molecular weight (Mw) of the binder polymer A-1 was 35,000.

[0126] The weight average molecular weight was measured by gel permeation chromatography (GPC) and calculated using a calibration curve of standard polystyrene. The GPC conditions are as follows: (GPC conditions) Columns: Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R400M (Showa Denko Materials Co., Ltd.) Eluent: Tetrahydrofuran Measurement temperature: 40℃ Flow rate: 2.05mL / min Detector: Hitachi L-2490 RI (Hitachi, Ltd.)

[0127] <Preparation of Resin Composition for Forming Barrier Layer> A resin composition for forming a barrier layer was obtained by mixing the components shown in Table 1 below in the amounts (unit: parts by mass) shown in the same table. Specifically, the water-soluble resin was slowly added to a solvent at room temperature, and after the entire amount was added, the mixture was stirred for 1 hour, and then the leveling agent was mixed and dissolved uniformly, thereby obtaining a resin composition for forming a barrier layer. The amount of the water-soluble resin in Table 1 is the amount of solid content.

[0128] <Preparation of Photosensitive Resin Composition> Next, photosensitive resin compositions were obtained by mixing the components shown in Table 1 in the amounts (unit: parts by mass) shown in the same table. Note that the blending amount of the binder polymer in Table 1 is the blending amount in terms of solid content.

[0129] [Table 1]

[0130] Details of each component in Table 1 are as follows. (Water-soluble resin) *1: HC-100G (polyvinyl alcohol, manufactured by Taisei Chemical Co., Ltd., product name: Maltite HC-100G, solid content 13.5% by mass) *2: K-30 (Polyvinylpyrrolidone, manufactured by Nippon Shokubai Co., Ltd., product name)

[0131] (Leveling agent) *3: WS-314 (acrylic polymer, manufactured by Kyoeisha Chemical Co., Ltd., product name, components: 48% by mass of acrylic polymer and 52% by mass of 3-methoxy-3-methyl-1-butanol, composition of acrylic polymer: copolymer of approximately 6.89 mol% butyl (meth)acrylate, approximately 61.4 mol% isobutyl (meth)acrylate and approximately 31.7 mol% terminal methoxy group EO modified (meth)acrylate)

[0132] Component (A): Binder polymer *4: A-1 (binder polymer A-1 obtained in Synthesis Example 1)

[0133] (B) Component: Photopolymerizable compound *5: FA-321M (product name, manufactured by Showa Denko Materials Co., Ltd.) 2,2-Bis(4-(methacryloxypolyethoxy)phenyl)propane (average 10 mol ethylene oxide adduct) *6: FA-024M (product name, manufactured by Showa Denko Materials Co., Ltd.) (PO)(EO)(PO) modified dimethacrylate (average 6 mol of ethylene oxide and average 12 mol of propylene oxide adduct (total value)) *7: BP-2EM (Kyoeisha Chemical Co., Ltd., product name) 2,2-bis(4-(methacryloxypolyethoxy)phenyl)propane (EO groups: 2.6 (total value))

[0134] Component (C): Photopolymerization initiator *8: B-CIM (product name, manufactured by Hodogaya Chemical Co., Ltd.) 2,2'-Bis(2-chlorophenyl)-4,4',5,5'-tetraphenylbiimidazole

[0135] (D) Component: Photosensitizer *9: PZ-501D (product name, manufactured by Nippon Chemical Industry Co., Ltd.) 1-Phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline

[0136] Component (E): Polymerization inhibitor *10: Q-TBC-5P (manufactured by DIC Corporation, product name) 4-tert-Butylcatechol *11:LA-7RD (product name, manufactured by ADEKA Corporation) 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl

[0137] Other Ingredients *12: Leuco Crystal Violet (Yamada Chemical Industry Co., Ltd.) (color developer) *13: SF-808H (manufactured by Sanwa Kasei Co., Ltd., product name) (adhesion promoter) Mixture of carboxybenzotriazole, 5-amino-1H-tetrazole and methoxypropanol *14: Malachite Green (Osaka Organic Chemical Industry Co., Ltd.) (dye)

[0138] [Examples 1 to 3, Comparative Examples 1 and 3] <Preparation of Photosensitive Element> (Preparing the support film) Five types of PET films A to E containing lubricant (particles) were prepared as support films for photosensitive elements. The thickness of each of the PET films A to E was 16 μm. The size and amount of the lubricant (particles) contained in the PET films A to E differ. The following measurements were carried out on the PET films A to E. The results are shown in Table 2.

[0139] [Number of particles with a diameter of 0.8 μm or more] For PET films A to E, the number of particles with a diameter of 0.8 μm or more on the surface F1 on the side on which the barrier layer or photosensitive layer is formed is 0.0225 mm 2 The number of particles per one was measured using a laser microscope under the following conditions.

[0140] -Measurement conditions- Equipment: Hybrid laser microscope (manufactured by Lasertec Corporation, product name: OPTELICS HYBRID) Measurement range: 150μm square Measurement details: Acquire a brightness image of the surface F1 of the PET film. The acquired brightness image is binarized to measure the particle (lubricant) size and number. 2 The number of particles within the measurement range was calculated. The measurement was performed five times, and the average value was taken as the number of particles.

[0141] [Number of particles with a diameter of 5.0 μm or more] For PET films A to E, the number of particles with a diameter of 5.0 μm or more on the surface F1 on the side on which the barrier layer or photosensitive layer is formed is 0.0225 mm 2 The number of particles per unit area was measured in the same manner as in the measurement of the number of particles with a diameter of 0.8 μm or more.

[0142] [Haze] The haze of the PET films A to E was measured using a turbidity meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH-5000") in accordance with the method prescribed in JIS K7105.

[0143] [Linear expansion coefficient in TD direction] The linear expansion coefficients in the TD direction of the PET films A to E were measured by the following method. First, the PET film was cut into a size of 3 mm x 30 mm so that the TD direction was the longitudinal direction to obtain a test piece. The test piece was set in a thermomechanical analyzer (Seiko Instruments Inc., SSC5200 type) in tension mode with a chuck distance of 20 mm. The set test piece was treated under conditions of a temperature range of 20 to 250°C and a heating rate of 5°C / min, and the linear expansion coefficients in the TD direction of the test piece were measured. From the measurement results, the linear expansion coefficients at 80 to 110°C were read. This linear expansion coefficient is the average value at 80 to 110°C.

[0144] (Creation of Barrier Layer) Next, the resin composition for forming a barrier layer was applied to the surface F1 of the PET film (support film) so as to have a uniform thickness, and dried for 10 minutes in a hot air convection dryer at 95°C to form a barrier layer having a thickness of 5 μm after drying.

[0145] (Preparation of photosensitive layer) Next, a photosensitive resin composition was applied onto the barrier layer so as to have a uniform thickness, and dried for 10 minutes in a hot air convection dryer at 100° C. to form a photosensitive layer having a dried thickness of 15 μm.

[0146] Next, a polyethylene protective film (protective layer) (manufactured by Tamapoly Co., Ltd., product name "NF-15A") was laminated onto this photosensitive layer to obtain a photosensitive element in which a PET film (support film), a barrier layer, a photosensitive layer, and a protective layer were laminated in that order.

[0147] [Comparative Example 2] <Preparation of Photosensitive Element> A photosensitive element having a PET film (support film), a photosensitive layer, and a protective layer laminated in this order was obtained in the same manner as in Example 2, except that no barrier layer was provided.

[0148] [Comparative Example 4] <Preparation of Photosensitive Element> A photosensitive element having a PET film (support film), a photosensitive layer, and a protective layer laminated in this order was obtained in the same manner as in Comparative Example 3, except that no barrier layer was provided.

[0149] [evaluation] <Preparation of Laminate> A Cu-sputtered PET film (manufactured by Geomatec Co., Ltd., plate thickness: 125 μm, Ra<50 nm) was heated to 80° C. as a substrate, and the above-mentioned photosensitive element was pressed onto the substrate while peeling off the protective layer so that the photosensitive layer was in contact with the copper surface. Pressing was performed using a heat roll at 110° C. at a roll speed of 1.0 m / min under a pressure of 0.40 MPa using a heat roll. In this way, a laminate (Examples 1 to 3, Comparative Examples 1 and 3) in which the substrate, the photosensitive layer, the barrier layer, and the support film were laminated in this order, or a laminate (Comparative Examples 2 and 4) in which the substrate, the photosensitive layer, and the support film were laminated in this order was obtained. These laminates were used as test pieces in the following tests. HLM-3000 (manufactured by Taisei Laminator Co., Ltd., product name) was used as a laminator.

[0150] <Measurement of minimum development time> The support film was peeled off from the test piece to expose the barrier layer or photosensitive layer, and a 1% by mass aqueous solution of sodium carbonate at 30° C. was sprayed on the exposed surface. The time until the photosensitive layer was completely removed was measured and taken as the minimum development time.

[0151] <Formation of Resist Pattern> The support film was peeled off from the test pieces of Examples 1 to 3 and Comparative Examples 1 and 3, and a glass chrome type phototool (size: 9 cm × 9 cm, having three types of wiring patterns with line width / space width of 10 μm / 10 μm, 15 μm / 15 μm, and 20 μm / 20 μm evenly distributed, or an adhesion negative: having a wiring pattern with line width / space width of x / x (x: 1 to 18, unit: μm)) was placed on the exposed barrier layer as a negative, and a light exposure of 110 mJ / cm was performed using a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240-SM-XJ01") with an ultra-high pressure mercury lamp (365 nm) as a light source. 2 The photosensitive layer was exposed to an exposure dose of 10000000000000. After exposure, a 1% by weight aqueous solution of sodium carbonate at 30°C was sprayed for twice the minimum development time to remove the unexposed areas and form a resist pattern. The same operation was repeated five times to prepare five resist patterns for evaluation.

[0152] On the other hand, for the test pieces of Comparative Examples 2 and 4, the above-mentioned phototool was placed on the support film, and a projection exposure apparatus (manufactured by Ushio Inc., product name "UX-2240-SM-XJ01") with an ultra-high pressure mercury lamp (365 nm) as the light source was used to expose the test pieces to light at 110 mJ / cm 2 The photosensitive layer was exposed through the support film at an exposure dose of 1000000000000000. After exposure, the support film was peeled off to expose the photosensitive layer, and a 1% by weight aqueous solution of sodium carbonate at 30°C was sprayed on the layer for twice the minimum development time to remove the unexposed areas and form a resist pattern. The same operation was repeated five times to prepare five resist patterns for evaluation.

[0153] <Measurement of the number of defects> The resist pattern formed by the above method (in a 9 cm × 9 cm area, three types of resist patterns (length 9 cm) with line width / space width of 10 μm / 10 μm, 15 μm / 15 μm, and 20 μm / 20 μm are evenly provided over a width of 9 cm so that the number of each is the same) was inspected using an automatic optical inspection device (AOI, manufactured by Orbotech Japan, product name "Ultra Fusion 600"), and the number of resist defect parts where the resist was missing by 5 μm or more was counted. The number of the above resist defect parts was counted for five resist patterns for evaluation, and the total was taken as the number of defects. The results are shown in Table 2.

[0154] <Measurement of LER> The LER (Line Edge Roughness) of the resist pattern formed by the above method was measured by the following method. That is, using a Computer Numerical Control image measurement system (manufactured by Nikon Corporation, product name "NEXIV VMZ-R4540"), an area where a resist pattern with a line width / space width of 5 μm / 5 μm was formed was imaged. In the scanning measurement of NEXIV VMZ-R4540, the contour of the resist pattern on the substrate was specified, and for six lines of the resist pattern, the coordinates of the contour of the resist pattern were measured. In the measurement of the coordinates, the measurement of 260 points of coordinates engraved at 0.2 μm intervals for a length of 52 μm was performed for each of the contours on one side and the other side of the line. Also, these measurements were performed three times for each of the six lines. As a result, a total of 9360 points of coordinates were measured. Then, based on the measured 9360 points of coordinates, the variation (3σ) of the contour of the resist pattern was calculated. σ is the standard deviation, and 3σ of the contour of the resist pattern is the LER (Line Edge Roughness). The results are shown in Table 2.

[0155] <Evaluation of Laminability> A copper-clad laminate (manufactured by Showa Denko Materials Co., Ltd., product name "MCL-E-679", size: 500 mm or more x 500 mm or more), which is a glass epoxy material with copper foil (thickness: 35 μm) laminated on both sides, was pickled and washed with water, then air-dried and heated to 80 ° C. While peeling off the protective layer, the above-mentioned photosensitive element was pressed onto the copper-clad laminate so that the photosensitive layer was in contact with the copper surface. Pressing was performed using a 110 ° C. heat roll at a roll speed of 1.0 m / min under a pressure of 0.40 MPa. After pressing, the presence or absence of voids between the copper-clad laminate and the photosensitive layer was observed and evaluated based on the following evaluation criteria. The results are shown in Table 2. A: No voids were observed. B: Voids were rarely observed. C: Voids were rarely observed.

[0156] [Table 2] [Explanation of symbols]

[0157] Reference Signs List 1: photosensitive element, 2: support film, 3, 20: barrier layer, 4, 30: photosensitive layer, 5: protective layer, 32: resist pattern, 40: conductive layer, 42: conductive layer after etching, 50: insulating layer, 60: plating layer, 62: plating layer after etching, 70: conductive pattern, 80: actinic light.

Claims

1. A photosensitive element comprising a support film, a barrier layer, and a photosensitive layer in this order, The number of particles with a diameter of 0.8 μm or larger, measured on the barrier layer side surface of the support film, is 0.0225 mm. ２ A photosensitive element consisting of 5 to 100 elements per unit.

2. The photosensitive element according to Claim 1, wherein the coefficient of linear expansion of the support film in the TD direction at 80 to 110°C is 170 ppm / K or less.

3. The photosensitive element according to claim 1, wherein the barrier layer comprises a water-soluble resin.

4. The photosensitive element according to claim 1, wherein the thickness of the barrier layer is 2 to 12 μm.

5. The photosensitive element according to claim 1, wherein the number of particles with a diameter of 5.0 μm or more measured on the barrier layer side surface of the support film is 0 per 0.0225 mm².

6. A step of arranging a photosensitive layer, a barrier layer, and a support film on a substrate in this order from the substrate side, using the photosensitive element described in any one of Claims 1 to 5, The steps include removing the support film and exposing the photosensitive layer to active light through the barrier layer, A step of removing the uncured portion of the photosensitive layer and the barrier layer from the substrate, A method for forming a resist pattern, comprising the characteristics of a resist pattern.

7. A method for manufacturing a printed wiring board, comprising the step of etching or plating a substrate on which a resist pattern has been formed by the resist pattern formation method described in Claim 6 to form a conductor pattern.

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