Photosensitive element

Abstract

Provided is a photosensitive element capable of forming a resist pattern having a thin photosensitive resin composition layer and high resolution, and capable of improving the manufacturing yield of a conductor pattern by suppressing resist pattern defects caused by a support film. In one embodiment, provided is a photosensitive element comprising a support film and a photosensitive resin composition layer, wherein: (1) the thickness of the photosensitive resin composition layer is 30 μm or less; (2) a hole pattern having a diameter of 10 μm or less can be resolved; and (3) the number of foreign substances having a long diameter of 5-30 μm, which are present inside the support film is 0.0004 / mm2 or less; and (4) the ratio of the number of foreign substances having no voids observable by an optical microscope having an objective lens with a numerical aperture of 0.6 to the number of the foreign substances having a major axis of 5-30 μm is 50% or less.

Description

Photosensitive element

[0001] The present invention relates to a photosensitive element.

[0002] Resists are used in various electronic devices to manufacture printed wiring boards and the like for mounting components, semiconductors, and the like. Conventionally, photosensitive elements, so-called dry film photoresists (hereinafter sometimes referred to as DF), have been used, which are formed by laminating a photosensitive resin composition layer on a support film and, if necessary, further laminating a protective film on the photosensitive resin composition layer. Currently, alkaline development-type photosensitive resin composition layers, which use a weak alkaline aqueous solution as a developer, are commonly used. To produce a printed wiring board or the like using DF, for example, the following steps are taken. If the DF has a protective film, the protective film is first peeled off. Then, the DF is laminated onto a substrate for producing permanent circuits, such as a copper-clad laminate or a flexible substrate, using a laminator or the like, and exposed through a wiring pattern mask film or the like. Next, the support film is peeled off as needed, and the uncured portions of the photosensitive resin composition layer (e.g., the unexposed portions in a negative-type photosensitive resin composition) are dissolved or dispersed and removed using a developer, forming a cured resist pattern (hereinafter sometimes simply referred to as a resist pattern) on the substrate.

[0003] After forming a resist pattern, the process of forming a circuit can be broadly divided into two methods. The first method is a method (etching method) in which the substrate surface not covered by the resist pattern (e.g., the copper surface of a copper-clad laminate) is etched and then the resist pattern portion is removed with an alkaline aqueous solution stronger than the developer. The second method is a method (plating method) in which the substrate surface is plated with copper, solder, nickel, tin, etc., and then the resist pattern portion is removed in the same manner as the first method, and the exposed substrate surface (e.g., the copper surface of a copper-clad laminate) is etched. Cupric chloride, ferric chloride, cupric ammonia complex solution, etc. are used for etching. In recent years, with the miniaturization and weight reduction of electronic devices, printed wiring boards have become increasingly finer and denser, and high-performance DFs that provide high resolution, good line width reproducibility, etc. are required in the above-mentioned manufacturing process.

[0004] In particular, there is a demand for photosensitive elements that achieve high-definition and multi-layering with high yields for package substrates. Because yields are heavily influenced by the defect rate caused by foreign matter in the photosensitive element, the importance of reducing foreign matter is increasing. In recent years, progress has been made in identifying the causes of defects caused by foreign matter, and many of these have been improved, but the effectiveness of reducing the defect rate has plateaued. Meanwhile, demands for yield are becoming stricter every year, making it extremely important to suppress not only causes of defects that occur frequently, but also causes of defects that occur infrequently.

[0005] Patent Document 1 describes a photosensitive resin laminate roll formed by rolling up a photosensitive resin laminate including a support film and a photosensitive resin composition layer containing a photosensitive resin composition formed on the support film, in which the support film has regions in which, when small pieces of 0.75 mm × 11 mm are cut out from the support film at any 10 different locations, the number of fine particles having a diameter of 2 μm or more contained in each small piece is 200 or less on a number average at the 10 locations, and the back surface of the support film includes a region in which the arithmetic mean roughness is 0.01 μm or more.

[0006] Patent Document 2 describes a photosensitive resin laminate comprising a support film and a photosensitive resin composition layer formed on the support film and containing a photosensitive resin composition, in which, when square pieces with sides of 5 mm are cut out from any 10 positions on the support film, the number of fine particles of 1.5 μm or more and less than 4.5 μm contained in each small piece is 0 to 200 on average from the 10 positions.

[0007] Patent Document 3 discloses a method for detecting foreign particles having an outer diameter of 1.0 μm or more and 10.0 μm or less, which contain one or more elements selected from calcium, aluminum, antimony, and silicon, at a density of 1 to 100 particles / 100 cm. 2 A biaxially oriented polyester film for dry film resist is described.

[0008] Patent Document 4 discloses a photosensitive resin laminate comprising a support film and a photosensitive resin composition layer formed on the support film, the support film containing fine particles, and the support film is observed at a depth of 13.5 mm using an incident-light laser microscope. 2 The present invention describes a photosensitive resin laminate that includes a region in which the total area ratio of optically abnormal regions when observed over an area of ​​300 ppm or less.

[0009] Patent Document 5 discloses a photosensitive element having a support film (A) and a photosensitive resin composition layer (B) in this order, in which the developed area ratio Sdr of the interface of the support film (A) on the side opposite to the side in contact with the photosensitive resin composition layer (B) as defined in ISO 25178 is A1 (%) is Sdr A1 <0.005(%).

[0010] JP 2019-101405 A, International Publication No. 2018 / 105620, JP 2022-158018 A, International Publication No. 2019 / 124452, International Publication No. 2022 / 163652

[0011] In areas where light irradiation of the photosensitive resin composition layer is insufficient or non-uniform due to foreign matter on the support film, defects in the formed conductor pattern may occur. The techniques described in Patent Documents 1 to 5 make it possible to address the frequent occurrence of foreign matter on support films. However, these conventional techniques have a small foreign matter inspection area, and therefore defects caused by foreign matter still occur despite the small amount of foreign matter detected in the foreign matter inspection area. In particular, when the photosensitive resin composition layer is thin, defects in the resist pattern are likely to appear as significant defects such as holes. Furthermore, when forming a high-resolution resist pattern, even slight defects in the resist pattern are undesirable. Therefore, when forming a thin photosensitive resin composition layer or a high-resolution resist pattern, further reduction of foreign matter that causes defects in the resist pattern is required to reduce resist pattern defects and improve the manufacturing yield of conductor patterns and / or accurately estimate the yield.

[0012] One aspect of the present invention aims to solve the above-mentioned problems and to provide a photosensitive element that can form a thin photosensitive resin composition layer and a high-resolution resist pattern, and that can suppress defects in the resist pattern caused by the support film, thereby improving the manufacturing yield of the conductor pattern.

[0013] The present invention encompasses the following items: [Item 1] A photosensitive element comprising a support film and a photosensitive resin composition layer, wherein (1) the thickness of the photosensitive resin composition layer is 30 μm or less, (2) a circular hole pattern of 10 μm or less in diameter can be resolved, and (3) the number of foreign particles having a major axis of 5 μm to 30 μm present inside the support film is 0.0004 pieces / mm 2 (4) A photosensitive element in which the number of foreign particles having a major axis of 5 μm to 30 μm that do not have voids and are observable with an optical microscope having an objective lens with a numerical aperture of 0.6 is 50% or less. [Item 2] A photosensitive element in which the number of foreign particles having a major axis of 10 μm to 20 μm present inside the support film is 0.00015 particles / mm 2 Item 3. The photosensitive element according to item 1, wherein the number of foreign particles having a major axis of 10 μm to 20 μm that do not have voids and are observable with an optical microscope having an objective lens with a numerical aperture of 0.6 is 50% or less. 2[Item 4] The photosensitive element according to any one of items 1 to 3, wherein the support film includes a coating layer on a side opposite to the photosensitive resin composition layer side, the maximum load P when testing the surface of the support film on the coating layer side for slippage with a wafer in accordance with JIS K7125 is 0.1 N≦P≦5.0 N, and the developed area ratio Sdr of the surface of the support film on the coating layer side, as determined in accordance with ISO 25178, is 0.0001≦Sdr≦0.005. [Item 5] The photosensitive element according to any one of Items 1 to 4, wherein when square pieces with sides of 5 mm are cut out from any 10 positions on the support film, in each of the small pieces, the number average at the 10 positions is: 0 to 200 microparticles with a major axis of 1.5 μm or more and less than 4.5 μm; 0 to 10 microparticles with a major axis of 4.5 μm or more and less than 10 μm; and 0 to 1 microparticle. [Item 6] The photosensitive element according to any one of Items 1 to 5, wherein the photosensitive resin composition layer comprises: (A) an alkali-soluble polymer; (B) a compound having an ethylenically unsaturated bond; and (C) a polymerization initiator and / or sensitizer; the component (A) comprises, based on the total amount of the component (A), 15% by mass to 65% by mass of structural units derived from (meth)acrylic acid and 30% by mass to 85% by mass of structural units derived from styrene and / or a styrene derivative; the component (B) comprises 15% by mass or more of a di(meth)acrylate having a bisphenol A skeleton, based on the total solids content of the photosensitive resin composition layer; and the component (C) comprises 3% by mass or more of a compound having a biimidazole structure, based on the total solids content of the photosensitive resin composition layer.[Item 7] The photosensitive element according to any one of Items 1 to 6, wherein the photosensitive resin composition layer comprises: (A) an alkali-soluble polymer; (B) a compound having an ethylenically unsaturated bond; and (C) a polymerization initiator and / or sensitizer; the component (A) comprises, based on the total amount of component (A), 15 to 65% by mass of structural units derived from (meth)acrylic acid and 30 to 85% by mass of structural units derived from styrene and / or a styrene derivative; the component (B) comprises 15% by mass or more of a di(meth)acrylate having a bisphenol A skeleton, based on the total solids content of the photosensitive resin composition layer; the component (C) comprises 3% by mass or more of a compound having a biimidazole structure, based on the total solids content of the photosensitive resin composition layer; and the component (C) further comprises a compound having a skeleton of at least one derivative selected from the group consisting of pyrazoline derivatives, anthracene derivatives, benzophenone derivatives, naphthalene derivatives, and oxazole derivatives. [Item 8] The photosensitive element according to any one of Items 1 to 7, which is capable of resolving a pattern of circular holes having a diameter of 5 μm or less. [Item 9] A photosensitive element comprising a support film and a photosensitive resin composition layer, wherein (1) the thickness of the photosensitive resin composition layer is 30 μm or less, (2) a pattern of circular holes having a diameter of 10 μm or less can be resolved, and (3) the number of foreign particles having a major axis of 5 μm to 30 μm present in a range of 5% to 95% when a position on one surface of the support film is defined as 0%, a position on the other surface as 100%, and a position at the center in the thickness direction as 50% is 0.0004 particles / mm. 2 (4) A photosensitive element in which, among the foreign particles having a major axis of 5 μm to 30 μm, the number ratio of foreign particles having no voids observable with an optical microscope having an objective lens with a numerical aperture of 0.6 is 50% or less. [Item 10] When a position on one side of the support film is defined as 0%, a position on the other side as 100%, and a position at the center in the thickness direction as 50%, the number of foreign particles having a major axis of 10 μm to 20 μm present in a range of 5% to 95% is 0.00015 particles / mm 2Item 11. The photosensitive element according to Item 9, wherein the number of foreign particles having a major axis of 10 μm to 20 μm that do not have voids observable with an optical microscope having an objective lens with a numerical aperture of 0.6 is 50% or less. 2 11. The photosensitive element of item 10, wherein:

[0014] According to one aspect of the present invention, a photosensitive element can be provided that has a thin photosensitive resin composition layer and is capable of forming a high-resolution resist pattern, while suppressing defects in the resist pattern caused by the support film, thereby improving the manufacturing yield of the conductor pattern.

[0015] 1A and 1B are diagrams illustrating an example of a special foreign substance, an example of a conventional foreign substance, and a diagram illustrating a design for a yield test.

[0016] Hereinafter, exemplary embodiments for carrying out the present invention (hereinafter also referred to as "present embodiments") will be described in detail. Note that the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof. Note that, unless otherwise specified, the various parameters described below are measured according to the measurement methods in the examples described below or methods that are understood to be equivalent to these by those skilled in the art.

[0017] <Photosensitive Element> The photosensitive element of this embodiment includes a support film and a photosensitive resin composition layer. In one aspect, the photosensitive resin composition layer has a predetermined thickness or less. In one aspect, the photosensitive element is capable of resolving a circular hole pattern of a predetermined size or less. In one aspect, the number of foreign matter of a predetermined size present inside the support film is a predetermined number or less. In one aspect, of the foreign matter of the predetermined size, the ratio of the number of foreign matter that does not have voids observable with an optical microscope having an objective lens with a predetermined numerical aperture (and therefore a predetermined resolution) is a predetermined number or less.

[0018] Generally, the support film of a photosensitive element contains intentionally added fine particles to impart slip properties. If the major axis of the fine particles is approximately less than 1.5 μm, they do not interfere with the irradiation of the photosensitive resin composition layer with light. On the other hand, fine particles with a major axis of 1.5 μm or more are preferably not contained in the support film because they may cause the light irradiated onto the photosensitive resin composition layer to be insufficient or uneven. Since intentionally added fine particles usually have a particle size distribution, even if the average particle size is small, they may contain a small amount of fine particles with a major axis of 1.5 μm or more. Reducing the amount of fine particles with a major axis of 1.5 μm or more present in the support film is advantageous in terms of minimizing defects in the resist pattern.

[0019] The material of the intentionally added fine particles is usually not light-shielding in order to make the support film transparent. However, the fine particles may have a refractive index different from that of the matrix polymer of the support film. Furthermore, when the support film is stretched in the film-forming process, the fine particles may act as nuclei, and voids may be formed around the nuclei. Because the fine particles are not light-shielding, they cannot be detected by transmitted light observation with an optical microscope, but they can be detected with a polarizing microscope.

[0020] On the other hand, support films may contain foreign matter that was not intentionally added. Such foreign matter differs from the intentionally added fine particles described above in that it is detected as a light-blocking substance in transmitted light observation using an optical microscope. Such foreign matter originates from dust during support film production, contamination in piping, residual catalyst in the matrix polymer of the support film, etc. Even if the foreign matter is attached to the outside of the support film, it can be removed by cleaning. However, foreign matter inside the support film affects the exposure of the photosensitive resin composition layer, causing defects in the resist pattern. Through the research of the present inventors, it has been discovered that in high-resolution photosensitive elements, foreign matter with a characteristic shape present in the support film at an extremely low frequency causes defects in the resist pattern. Among foreign matter that cause optical abnormalities, such as reflectance or refractive index different from the surroundings or optical phenomena such as scattering and diffraction being stronger than the surroundings, particulate foreign matter present with voids has been previously known, but foreign matter present without voids has not been previously known, and was discovered through the research of the present inventors. The present inventors have also found that foreign matter without voids also causes defects in the resist pattern, just like foreign matter with voids.

[0021] More specifically, void-containing foreign matter includes hard particles unintentionally mixed into the support film, and as described in Patent Document 4, for example, voids are generated by stretching the support film during production. In contrast, void-free foreign matter typically has a characteristic flat shape. Therefore, it is believed that in void-free foreign matter, the foreign matter is encapsulated in a flexible gel or the like, and the gel or the like changes shape during stretching the support film during production, preventing voids from being formed. Void-free foreign matter occurs infrequently. However, when the photosensitive resin composition layer is thin and the photosensitive element has high resolution, even such infrequent foreign matter can significantly reduce the manufacturing yield of the conductor pattern. Therefore, this embodiment particularly focuses on reducing void-free foreign matter among foreign matters present inside the support film.

[0022] In this embodiment, foreign matter without voids is identified as foreign matter without voids that can be observed with an optical microscope having an objective lens with a numerical aperture of 0.6 (also referred to as special foreign matter in this disclosure), and foreign matter with voids is identified as foreign matter with voids that can be observed with an optical microscope having an objective lens with a numerical aperture of 0.6 (also referred to as conventional foreign matter in this disclosure). In an ideal optical system, the minimum distance that can be distinguished as two points is called resolution, and it is known that this resolution can be expressed by the following formula (a1) where the observation wavelength is λ (μm) and the numerical aperture is NA: Resolution = 0.61λ / NA (a1) (Rayleigh resolution). When dimension measurement is performed at an observation wavelength λ = 0.55 (μm) using the objective lens of a typical measuring microscope (magnification 50x, numerical aperture NA = 0.6), the resolution can be calculated to be 0.56 μm ideally. In other words, observation using an optical microscope with an objective lens with a numerical aperture of 0.6 refers to observation under conditions that allow sufficient differentiation between foreign particles with a major axis of 5 μm or greater and fine particles with a major axis of 1.5 μm or greater. Furthermore, according to the inventors' studies, even if an objective lens with a numerical aperture ranging from 0.5 to 0.7 is used instead of a 0.6 objective lens, measurement results are obtained that are substantially equivalent to those obtained when using a 0.6 objective lens. Therefore, in one embodiment, the 0.6 objective lens may be substituted with an objective lens with a numerical aperture ranging from 0.5 to 0.7. Furthermore, "observable" refers to a state in which the outline of the void region is clearly visible with an S / N ratio similar to that of the outer contour of the foreign particle. This means that when a binarization process is performed to extract the outlines of the optical microscope image, a separate outline (void region) is present in addition to the largest outer contour. Figure 1 shows an example of a special foreign particle, and Figure 2 shows an example of a conventional foreign particle.

[0023] In one embodiment, the number of foreign particles having a major axis of 5 μm to 30 μm present inside the support film is controlled to a predetermined level or less, and the number ratio of special foreign particles among the foreign particles is controlled to a predetermined level or less. In a photosensitive element having a thin photosensitive resin composition layer (more specifically, a thickness of 30 μm or less) and capable of forming a high-resolution pattern (more specifically, capable of resolving a circular hole pattern with a diameter of 10 μm or less), the reduction in the number of special foreign particles having a major axis of 5 μm to 30 μm is advantageous in terms of suppressing defects in the resist pattern caused by the support film and improving the manufacturing yield of the conductor pattern. Methods for reducing the number of foreign particles with a major axis of 5 μm to 30 μm can be one or more of the following: (1) adjusting the production conditions of the matrix polymer of the support film (e.g., the type and / or amount of catalyst); (2) removing foreign particles from the molten extrudate, which is the material for the support film, in advance by filtration or other means; (3) inspecting the support film for foreign particles for each lot and selecting lots whose number of foreign particles meets a desired standard; and (4) preventing contamination from the filtration of the molten extrudate to the production of the support film. These methods enable the desired reduction in the number of foreign particles while ensuring stable production of the support film. Furthermore, methods for reducing the number of special foreign particles with a major axis of 5 μm to 30 μm can be one or more of the above methods (1) to (4), particularly (1), (3), and (4).

[0024] In one embodiment, the photosensitive element is capable of resolving a circular hole pattern of 10 μm diameter or less. The ability to resolve a circular hole pattern of 10 μm diameter or less can be confirmed by the procedure outlined below and specifically specified in the [Examples] section. A photosensitive element laminate is obtained by laminating the photosensitive element onto an evaluation substrate. The support film surface side of the photosensitive element laminate is exposed to monochromatic i-line light. After exposure at an optimal exposure dose using a chrome glass photomask containing a circular hole design of 2 to 30 μm diameter, the photosensitive element laminate is developed. The optimal exposure dose is set as the exposure dose at which the resolved circular holes are measured to be 15 μm ± 0.2 μm when exposed with a 15 μm diameter mask. When 100 circular hole designs of 2 to 30 μm diameter are exposed at the optimal exposure dose, the smallest design with 98 or more holes is defined as the resolution value. When the resolution value is 10 μm diameter or less, a circular hole pattern of 10 μm diameter or less can be resolved. The resolution value is preferably 8 μmφ or less, or 5 μmφ or less. A smaller resolution value is advantageous, but in one embodiment, the resolution value may be 1 μmφ or more from the viewpoint of ease of production of the photosensitive element.

[0025] Examples of means for enabling the photosensitive element to resolve a circular hole pattern of 10 μmφ or less using the procedure specifically specified in the [Examples] section include, but are not limited to, reducing the thickness of the photosensitive resin composition layer and improving the balance between the alkali-solubility and hydrophobicity of the components contained in the photosensitive resin composition layer. Examples of means for improving the balance between the alkali-solubility and hydrophobicity of the components contained in the photosensitive resin composition layer include, but are not limited to, adjusting the types and amounts of the alkali-soluble components and hydrophobic components, for example, by setting the content of (meth)acrylic acid in the alkali-soluble polymer (A) within a certain range and setting the content of aromatic rings contained in the photosensitive resin composition layer within a certain range.

[0026] When the photosensitive resin composition layer is thin, the developer can easily penetrate to the bottom of the unexposed areas even in a fine pattern during development of the photosensitive element after exposure, making it easy to improve the resolution of the circular hole pattern.When the photosensitive resin composition layer has a good balance between alkali-solubility and hydrophobicity, the developer can easily penetrate and dissolve into the unexposed areas of the photosensitive element during development of the photosensitive element after exposure, making it easy to improve the resolution of the circular hole pattern.

[0027] Specifically, the following means are preferred. The thickness of the photosensitive resin composition layer is 30 μm or less. The content of structural units derived from (meth)acrylic acid in the alkali-soluble polymer (A) contained in the photosensitive resin composition layer is 15% by mass to 65% by mass, and the content of structural units derived from styrene and / or a styrene derivative is 30% by mass to 85% by mass. The content of di(meth)acrylate having a bisphenol A skeleton contained in the photosensitive resin composition layer is 15% by mass or more based on the total solids content of the photosensitive resin composition layer. The content of compound (C) having a biimidazole structure contained in the photosensitive resin composition layer is 3% by mass or more based on the total solids content of the photosensitive resin composition layer.

[0028] As means for enabling the photosensitive element to resolve a pattern of circular holes of 5 μm or less in diameter by the procedure specifically specified in the section [Examples], the following means are more preferred: - The thickness of the photosensitive resin composition layer is 15 μm or less. - The content of structural units derived from styrene and / or styrene derivatives in the alkali-soluble polymer (A) contained in the photosensitive resin composition layer is 40 mass% or more.

[0029] <Support Film> The support film may have a single-layer structure consisting of only a main layer, or a multilayer structure in which resin layers of different material compositions are laminated. In the case of a multilayer structure, an antistatic layer may be present. In one embodiment, a lubricant layer containing intentionally added fine particles (hereinafter also referred to as added fine particles) is disposed on one side A of the main layer, and on the other side B, (1) a lubricant layer containing added fine particles of the same amount and size as those on side A, (2) a lubricant layer containing added fine particles in a smaller amount than those on side A, (3) a lubricant layer containing added fine particles of smaller size than those on side A, or (4) a coating layer containing or not containing added fine particles may be disposed. In the case of structures (2), (3), or (4), it is preferable to dispose a photosensitive resin composition layer on side B. The presence of a lubricant layer on side A (the side opposite to the photosensitive resin composition layer) is preferable from the viewpoint of the slipperiness of the film, etc. In a typical embodiment, the main layer does not contain added fine particles.

[0030] The support film is preferably a transparent film that transmits light emitted from an exposure light source. Examples of polymers that constitute the support film (in the case of a multi-layer structure, the main layer and other layers (e.g., lubricant layer or coating layer)) include polyester (e.g., polyethylene terephthalate), polyvinyl alcohol, polyvinyl chloride, vinyl chloride copolymers, polyvinylidene chloride, vinylidene chloride copolymers, polymethyl methacrylate copolymers, polystyrene, styrene copolymers, polyacrylonitrile, polyamide, and cellulose derivatives. The support film may be stretched as necessary.

[0031] When the support film includes a lubricant layer, the lubricant layer may include a polymer and additive fine particles. Examples of additive fine particles include inorganic particles such as calcium carbonate, calcium phosphate, silica (silicon dioxide), kaolin, talc, titanium dioxide, alumina (aluminum oxide), barium sulfate, calcium fluoride, lithium fluoride, zeolite, and molybdenum sulfide; organic particles such as polyimide resins, modified olefin resins, crosslinked polystyrene resins, and silicone resins; and mixtures thereof. In one embodiment, the thickness of the lubricant layer is 0.2 μm or more, or 0.4 μm or more, or 0.8 μm or more, and in another embodiment, 2.0 μm or less, or 1.5 μm or less, or 1.0 μm or less. The lubricant layer is usually formed by coextrusion using a casting method (i.e., a method in which the material is heated and melted in an extruder, extruded through a die onto a cooled casting drum, and processed into a sheet).

[0032] When the support film includes a coating layer, the coating layer contains a polymer and may or may not contain additive fine particles. Examples of the polymer include polyester resins, epoxy resins, melamine resins, oxazoline compounds, carbodiimide compounds, isocyanate compounds, acrylic resins, and silicone resins. Examples of the fine particles include organic particles and inorganic particles (e.g., silica (silicon dioxide), titanium dioxide, and alumina (aluminum oxide)). The polymer and the fine particles may be used alone or in combination of two or more. From the viewpoints of dispersion stability and refractive index, spherical organic particles and spherical silica are particularly preferred. The coating layer containing additive fine particles differs from the above-mentioned lubricant layer in that it is applied to the stretched film by in-line coating or offline coating. In one embodiment, the thickness of the coating layer is 0.01 μm or more, or 0.04 μm or more, or 0.08 μm or more, and in one embodiment, 0.40 μm or less, or 0.20 μm or less, or 0.10 μm or less.

[0033] (Foreign matter with a major axis of 5 μm to 30 μm, special foreign matter) In the photosensitive element of this embodiment, the number of foreign matter with a major axis of 5 μm to 30 μm present inside the support film is kept to a predetermined value or less, and the ratio of special foreign matter (i.e., foreign matter with no voids observable with an optical microscope having an objective lens with a numerical aperture of 0.6) to the total number of foreign matter with a major axis of 5 μm to 30 μm is kept to a predetermined value or less. This allows for high yields to be achieved, for example, even in the manufacture of large-area (in one embodiment, 100 mm or more per side) package substrates with fine pitch designs. In the present disclosure, the "interior" of the support film refers to a range of 5% to 95% when the position on one side of the support film is defined as 0%, the position on the other side as 100%, and the position at the center in the thickness direction as 50%. When the support film has a multilayer structure, the thickness of layers on the main layer (e.g., lubricant layers, coating layers, etc.) is typically 5% or less on each side of the main layer relative to the 100% thickness of the main layer. Therefore, the above range of 5% to 95% typically corresponds to the main layer of the support film. Whether or not foreign matter is present inside the support film can be confirmed by observing it under incident light with an optical microscope.

[0034] In one embodiment, the number of foreign particles having a major axis of 5 μm to 30 μm present inside the support film is 0.0004 pieces / mm 2 or less, or 0.0002 pieces / mm 2 or less, or 0.0001 pieces / mm 2 It is desirable that the number of foreign matters is small, but from the viewpoint of ease of manufacturing the support film, in one embodiment, the number of foreign matters is 0.0003 pieces / mm 2 The number of foreign particles having a major diameter of less than 5 μm may be 0.0001 particles / mm. In addition, even if foreign particles having a major diameter of less than 5 μm are present, they have little effect on exposure. Furthermore, foreign particles having a major diameter of more than 30 μm are usually not present because they are removed in advance by filtering the material during the production of the support film. The inside of the support film may contain foreign particles having a major diameter of less than 5 μm and / or foreign particles having a major diameter of more than 30 μm. In one embodiment, the number of these particles is 0.0001 particles / mm. 2 or less, preferably 0 pieces / mm 2 However, in one embodiment, 0.00005 pieces / mm 2 It may be more than that.

[0035] Among foreign particles with major diameters of 5 μm to 30 μm, the number ratio of special foreign particles (foreign particles that do not have voids and are observable with an optical microscope having an objective lens with a numerical aperture of 0.6) is, in one embodiment, 50% or less, 40% or less, or 30% or less. The regions with higher light-shielding properties affect the dry film pattern. While voids refract light but do not block it, regions other than voids completely block light. Foreign particles with a large proportion of light-shielding areas, i.e., special foreign particles that do not contain voids (i.e., those with a large light-shielding area), are more likely to cause dry film pattern defects than conventional foreign particles containing voids. Therefore, a low number ratio means a higher substrate yield when comparing films with the same number of foreign particles. The number ratio is most preferably 0%, but in one embodiment, it may be 25% or more from the perspective of easy availability of support films.

[0036] Among foreign matter particles with a major diameter of 5 μm to 30 μm, foreign matter particles with a major diameter of 10 μm to 20 μm are those that are likely to slip through a filter and become contaminants. Therefore, it is preferable to reduce the number of foreign matter particles with a major diameter of 10 μm to 20 μm to a predetermined value or less, and it is particularly preferable to reduce the number of foreign matter particles with a major diameter of 5 μm to 30 μm to a predetermined value or less and to reduce the number of foreign matter particles with a major diameter of 10 μm to 20 μm to a predetermined value or less. The number of foreign matter particles with a major diameter of 10 μm to 20 μm present inside the support film is preferably 0.0004 particles / mm 2 or less, or 0.0002 pieces / mm 2 or less, or 0.0001 pieces / mm 2 The number is most preferably 0 pieces / mm 2 However, from the viewpoint of availability of the support film, in one embodiment, 2 It may be more than that.

[0037] Among the foreign particles having a major axis of 10 μm to 20 μm, the number ratio of special foreign particles (void-free foreign particles observable with an optical microscope having an objective lens with a numerical aperture of 0.6) is, in one embodiment, 50% or less, 30% or less, or 15% or less. The number ratio is most preferably 0%, but from the viewpoint of ease of obtaining support films, in one embodiment, it may be 40% or more.

[0038] The numbers of foreign matter particles with major axes of 5 μm to 30 μm, foreign matter particles with major axes of 10 μm to 20 μm, and special foreign matter particles are determined by optical microscope observation. More detailed procedures are described in the Examples section. In the Examples, the support film alone is evaluated, but the evaluation results are similar for support films obtained by peeling them from a photosensitive element. Foreign matter is evaluated over a large inspection area at least equivalent to the package substrate. The numerical values ​​in this embodiment are intended to be values ​​obtained by Inspection Method B described in the Examples below. In addition, this embodiment also encompasses embodiments in which the numerical values ​​obtained by Inspection Method A (another method) described in the Examples below are within the ranges listed in this disclosure (i.e., as values ​​obtained by Inspection Method B). Inspection Method B can be performed using an automatic inspection device during the production of the support film, and is advantageous in terms of simplicity.

[0039] The amount of metal element contained in the support film is preferably 20 ppm by mass or less, or 12 ppm by mass or less, from the viewpoint of reducing the number of foreign matters derived from metal aggregates. In one aspect, the amount of metal element is 1 ppm by mass or more, or 2 ppm by mass or more, from the viewpoint of ensuring a sufficient amount of catalyst for synthesizing the constituent polymer of the support film. In one aspect, the amount of the metal element may be the total content of antimony, germanium, and titanium, or in another aspect, the amount of antimony, germanium, or titanium.

[0040] In one embodiment, the foreign matter having a major axis of 5 μm to 30 μm contains one or more metal elements selected from the group consisting of antimony, germanium, and titanium. These metal elements may be used as catalysts for polyester. Thus, in one embodiment, the support film (particularly the main layer) contains polyester, and the foreign matter having a major axis of 5 μm to 30 μm, particularly the special foreign matter, contains one or more metal elements selected from the group consisting of antimony, germanium, and titanium.

[0041] (Fine Particles) In a specific embodiment, the number of foreign particles with a major axis of 5 μm to 30 μm and the ratio of the number of special foreign particles are controlled, and the number of fine particles on the support film is controlled to a predetermined value or less. This can further improve the manufacturing yield of the conductor pattern. 2 When small pieces of the film are cut out, the number of fine particles having a major axis of 1.5 μm or more and less than 4.5 μm is, in one embodiment, 0 to 200 particles per 10 small pieces, the number of fine particles having a major axis of 4.5 μm or more and less than 10 μm is, in one embodiment, 0 to 10 particles, and the number of fine particles having a major axis of 10 μm or more is, in one embodiment, 0 to 1 particle. These fine particles include both intentionally added fine particles and foreign matter. However, in the support film of this embodiment, the number of foreign matter having a major axis of 5 μm to 30 μm is 0.0004 particles / mm 2 Less than 0.1 pieces / 250 mm 2Since the number of foreign particles is less than 100%, it is believed that the number of foreign particles is extremely small. Therefore, the number of fine particles primarily reflects the number of fine particles intentionally added. The particle size of each fine particle can be the particle size of a primary particle or the particle size of an aggregate of primary particles. The diameter of a fine particle is defined as the longest width, i.e., the major axis, of the fine particle, even when the fine particle is not perfectly spherical. The particle size and number of fine particles are values ​​measured using a polarizing microscope over the entire thickness of the support film, and more specific measurement procedures are described in the [Examples] section. Even if a photosensitive element does not satisfy the above-mentioned specific fine particle major diameter and fine particle number when measured at 10 locations, if the specific fine particle major diameter and fine particle number are satisfied when measured at another 10 locations, the photosensitive element is included in the photosensitive element that satisfies the above-mentioned specific fine particle major diameter and fine particle number. An example of a method for obtaining a support film that satisfies the above-mentioned specific fine particle major diameter and fine particle number is a method for producing a support film using a film material that has been passed through a filter that removes fine particles with a major axis of 1.5 μm or more. In one embodiment, after using such a filter, the number of particles can be adjusted by adding particles later to increase the number of particles to within a desired range.

[0042] Of the total area of ​​the support film, preferably 10% or more, or 20% or more, or 30% or more, or 40% or more, or 50% or more, or 60% or more, or 70% or more, or 80% or more, or 90% or more, or about 100% (i.e., substantially the entire area) is a region having the above-mentioned specific particle long diameter and particle number.

[0043] There is no particular upper limit to the size of the fine particles having a major axis of 1.5 μm or more, but in one embodiment, it may be 4.0 μm or less, or 3.5 μm or less.

[0044] The number of fine particles with a major axis of 1.5 μm or more and less than 4.5 μm contained in a square piece of the support film, each 5 mm on a side, is preferably 200 or less, or 180 or less, or 150 or less, or 120 or less, or 100 or less, or 80 or less, or 50 or less, or 30 or less, or 20 or less, or 15 or less, or 10 or less, or 6 or less, or 3 or less, or 2 or less, or 1 or less, from the viewpoint of preventing line width thickening or deterioration of resolution when the focal position is shifted during exposure. Fine particles do not significantly affect these performances during normal exposure. On the other hand, particularly in direct writing, if the focus of the exposed portion is shifted due to substrate distortion, insufficient adhesion of the substrate to the stage, or unevenness on the substrate surface, the effect of light scattering by the fine particles becomes greater. As a result, line width thickening and / or deterioration of resolution (particularly clearness) may occur.

[0045] Fine particles with a major axis of 4.5 μm or more can deteriorate resolution even during normal exposure. On the other hand, fine particles with a major axis of less than 1.5 μm do not cause line width thickening or deterioration in resolution even when the focus is shifted during exposure. In one embodiment, the number average of fine particles with a major axis of 4.5 μm or more at 10 locations in the small piece may be 0 to 200 or 0 to 100, and the number of fine particles with a major axis of less than 1.5 μm may be 0 to 10,000 or 0 to 5,000.

[0046] The fine particles contained in the support film may be inorganic or organic fine particles. Examples of the fine particles include lubricants, additive aggregates, foreign matter mixed in raw materials, and foreign matter mixed in during the manufacturing process. Specific examples of the fine particles include inorganic particles such as calcium carbonate, calcium phosphate, silica (silicon dioxide), kaolin, talc, titanium dioxide, alumina (aluminum oxide), barium sulfate, calcium fluoride, lithium fluoride, zeolite, molybdenum sulfide, antimony, germanium, and titanium, crosslinked polymer particles, and organic particles such as calcium oxalate. These may be used alone or in combination of two or more.

[0047] (Characteristics of the Support Film) The thinner the support film, the fewer foreign matters there are inside, which is advantageous in terms of resolution, but if the thickness is excessively thin, problems such as elongation deformation in the winding direction due to tension, tearing due to minute scratches, and wrinkles during lamination due to insufficient film strength may occur during processes such as coating the photosensitive resin composition layer and winding the photosensitive element. From the above viewpoints, the thickness of the support film is preferably 5 μm or more, or 6 μm or more, and preferably 20 μm or less, or 16 μm or less, or 12 μm or less.

[0048] The haze of the support film is preferably 5% or less, or 2% or less, or 1.5% or less, or 1% or less from the viewpoint of suppressing light scattering during exposure. In one embodiment, the haze may be 0.01% or more from the viewpoint of ease of production of the support film. The haze can be measured with a haze meter.

[0049] At least one surface of the support film may be subjected to a smoothing treatment such as calendaring, and / or a roughening treatment such as plasma treatment or sandblasting. In this case, the exposure light is less likely to be blocked by foreign matter inside the support film, making it easier to irradiate the photosensitive resin composition layer, thereby improving the resolution of the photosensitive element. In one embodiment, the surface of the support film facing the photosensitive resin composition layer (also referred to as the coated surface in this disclosure) may be a smooth surface, and the surface opposite the photosensitive resin composition layer (also referred to as the uncoated surface in this disclosure) may be a rough surface. A smooth coated surface may be advantageous in terms of resolution. On the other hand, a rough uncoated surface may be advantageous in terms of slipperiness.

[0050] The developed area ratio Sdr of the uncoated surface is preferably 0.0001 or more, or 0.0005 or more, or 0.0010 or more from the viewpoint of slipperiness, and preferably 0.0100 or less, or 0.0080 or less, or 0.0050 or less from the viewpoint of resolution. The developed area ratio is a value obtained in accordance with ISO 25178, and a more detailed measurement method will be described later in the section [Examples]. In one embodiment, the support film has a coating layer, and the developed area ratio Sdr is a value of the surface of the support film facing the coating layer (the surface of the coating layer in one embodiment).

[0051] When the sliding property of the uncoated surface with a wafer is tested in accordance with JIS K7125, the maximum load P in one embodiment is 0.1 N≦P≦5.0 N. From the viewpoint of reducing slippage when using a roll, the maximum load P is preferably 0.1 N or more, or 0.5 N or more, or 1.0 N or more, and from the viewpoint of good sliding property, it is preferably 5.0 N or less, or 3.0 N or less, or 2.0 N or less. In one embodiment, the support film has a coating layer, and the maximum load P is the value on the surface of the support film facing the coating layer (the surface of the coating layer in one embodiment).

[0052] The arithmetic mean roughness Ra of the coated surface is preferably 30 nm or less, or 20 nm or less, or 10 nm or less, from the viewpoint of suppressing light scattering during exposure. In one embodiment, the calculated mean roughness Ra may be 1.0 nm or more, from the viewpoint of ease of manufacturing the support film. The method for measuring the arithmetic mean roughness Ra is described in the section [Examples].

[0053] The static friction coefficient of the uncoated surface of the support film against a member in contact with the uncoated surface is preferably 2.0 or less, or 1.8 or less, or 1.5 or less, or 1.2 or less, or 1.0 or less, or 0.9 or less, or 0.8 or less, or 0.7 or less, or 0.6 or less, or 0.5 or less, or 0.4 or less, or 0.3 or less, or 0.2 or less, or 0.1 or less, from the viewpoint of roll winding properties when the photosensitive element is in the form of a roll. A smaller static friction coefficient results in better sliding of the photosensitive element and better roll winding properties, but from the viewpoint of preventing shear, the static friction coefficient is preferably 0.05 or more, or 0.1 or more, or 0.2 or more, or 0.3 or more. The static friction coefficient is a value measured by the method specified in JIS K7125.

[0054] Examples of methods for controlling the surface properties of the uncoated surface (developed area ratio, slipperiness with respect to the wafer, or static friction coefficient) include a method of reducing friction of the uncoated surface by surface roughening, a method of reducing friction of the surface of a member that comes into contact with the uncoated surface and that comes into contact with the support film by surface roughening, and combinations of these. Surface roughening can be achieved by plasma treatment, sandblasting, etc.

[0055] The surface resistivity of the uncoated surface is preferably 1.0×10 from the viewpoint of preventing static electricity of the photosensitive element. 13 Ω or less, or 1.0 x 10 11 Ω or less. When the photosensitive element is taken out by unwinding from the photosensitive element, static electricity may be generated between the member in contact with the uncoated surface of the support film and the uncoated surface of the support film, and this static electricity may cause dust, dirt, etc. to adhere to the support film and deteriorate handling. Setting the surface resistivity of the uncoated surface of the support film within the above range is advantageous in terms of the anti-static effect due to the low surface resistivity. On the other hand, from the viewpoint of ease of production of the support film, the surface resistivity of the uncoated surface of the support film is, in one embodiment, 1.0 × 10 7 Ω or more, or 1.0 x 10 8 It may be Ω or more.

[0056] <Photosensitive Resin Composition Layer> From the viewpoint of forming a highly precise pattern by imparting high resolution to the photosensitive element, the thickness of the photosensitive resin composition layer is, in one embodiment, 30 μm or less, or 25 μm or less, or 15 μm or less, or 7 μm or less. From the viewpoint of preventing an excessive decrease in film strength and reducing defects in the resist pattern, the thickness may be, in one embodiment, 3 μm or more, or 5 μm or more.

[0057] The photosensitive resin composition layer may be composed of a photosensitive resin composition containing (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated double bond, and (C) a photopolymerization initiator and / or sensitizer. The photosensitive resin composition preferably contains, based on the total solids mass of the photosensitive resin composition, 10% to 90% by mass of (A) the alkali-soluble polymer; 5% to 70% by mass of (B) the compound having an ethylenically unsaturated double bond; and 0.01% to 20% by mass of (C) the photopolymerization initiator and / or sensitizer. Each component will be described below in order. It should be noted that the total solids mass of the photosensitive resin composition corresponds to the total solids mass of the photosensitive resin composition layer.

[0058] [Component (A): Alkali-Soluble Polymer] The alkali-soluble polymer of component (A) preferably has a carboxyl group, and from the viewpoint of suitably exhibiting alkali solubility, it preferably has an acid value of 50 to 600 mgKOH / g. The acid value of component (A) may be 60 mgKOH / g or more, or 80 mgKOH / g or more, or 500 mgKOH / g or less, or 400 mgKOH / g or less.

[0059] The component (A) preferably has a repeating unit containing at least one selected from the "first monomers" described below, and more preferably has a repeating unit containing both at least one selected from the "first monomers" and at least one selected from the "second monomers" described below. Furthermore, the proportion of the monomer components in the component (A) is the copolymerization ratio when only one alkali-soluble polymer is used as the component (A), and is a weighted average of the copolymerization ratios when two or more alkali-soluble polymers are used as the component (A), with the content ratio of each alkali-soluble polymer being used as the weight.

[0060] The proportion of aromatic rings in component (A) may be 0.0045 mol / g or more. The aromatic rings may be derived from the first monomer, the second monomer, or both the first and second monomers. Since it is easier to achieve the desired component (A), it is preferable that the proportion of aromatic rings is derived from at least the second monomer. The proportion of aromatic rings in component (A) can be calculated by taking a weighted average of the proportions of aromatic rings contained in each monomer component in component (A) based on the content of each monomer component in component (A). The proportion of aromatic rings contained in each monomer component in component (A) can be calculated by (the number of aromatic rings contained in one monomer molecule / the molecular weight of the monomer).

[0061] The weight average molecular weight (Mw) of component (A) is preferably 10,000 to 60,000. A weight average molecular weight of 60,000 or less is preferred from the standpoint of achieving both flexibility and resolution of the resist pattern, and from the same standpoint, a weight average molecular weight of 55,000 or less is more preferred, and a weight average molecular weight of less than 50,000 is even more preferred. From the same standpoint, a weight average molecular weight of 10,000 or more is preferred, a weight average molecular weight of 14,000 or more is more preferred, and a weight average molecular weight of 25,000 or more is even more preferred.

[0062] The polydispersity of component (A) {weight average molecular weight (Mw) of component (A) / number average molecular weight (Mn) of component (A)} is preferably 1.0 to 6.0, more preferably 1.0 to 5.0, even more preferably 1.0 to 4.0, and particularly preferably 1.0 to 3.0.

[0063] When a mixture of two or more components is used as the component (A), the molecular weights and polydispersities of the multiple components (A) are preferably selected so that the weighted average values, when the content ratio is used as the weight, fall within the respective ranges.

[0064] (First Monomer) The first monomer has a carboxyl group in its molecule. Examples of the first monomer include (meth)acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, 4-vinylbenzoic acid, maleic anhydride, and maleic acid half ester. Among these, (meth)acrylic acid is preferred, and methacrylic acid is more preferred, from the viewpoint of excellent adhesion and resolution. In this specification, "(meth)acrylic acid" means acrylic acid or methacrylic acid, "(meth)acryloyl group" means acryloyl group or methacryloyl group, and "(meth)acrylate" means "acrylate" or "methacrylate".

[0065] The proportion of the first monomer in component (A) is preferably 10 to 50% by mass, based on the total mass of all monomer components. A proportion of 10% by mass or more is preferred from the viewpoint of excellent adhesion and resolution, with 15% by mass or more being more preferred, 18% by mass or more being even more preferred, 21% by mass or more being even more preferred, 23% by mass or more being particularly preferred, and 24% by mass or more being most preferred. A proportion of 50% by mass or less is preferred from the viewpoint of excellent adhesion and resolution, with 35% by mass or less being more preferred, 30% by mass or less being even more preferred, 29% by mass or less being even more preferred, 27% by mass or less being particularly preferred, and 26% by mass or less being most preferred.

[0066] Based on the total amount of component (A), the proportion of structural units derived from (meth)acrylic acid is preferably 15% by mass or more, or 18% by mass or more, or 21% by mass or more, and preferably 50% by mass or less, or 35% by mass or less, or 30% by mass or less.

[0067] (Second Monomer) The second monomer has at least one polymerizable unsaturated group in its molecule. Examples of the second monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, pentamethylpiperidyl (meth)acrylate, tetramethylpiperidyl (meth)acrylate, and tetrahydrofurfuryl. (meth)acrylates such as (meth)acrylate, phenoxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, methoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate; styrene derivatives such as methylstyrene, vinyltoluene, tert-butoxystyrene, acetoxystyrene, styrene dimer, and styrene trimer; esters of vinyl alcohol such as vinyl acetate; and (meth)acrylonitrile.

[0068] The second monomer preferably includes a compound having an aromatic ring. The proportion of this compound in component (A) is preferably 45 to 90% by mass, based on the total mass of all monomer components. A proportion of 45% by mass or more is preferred from the viewpoint of excellent adhesion and resolution, with 50% by mass or more being more preferred, 55% by mass or more being even more preferred, 60% by mass or more being even more preferred, and 65% by mass or more being particularly preferred. A proportion of 90% by mass or less is preferred from the viewpoint of excellent developability, with 80% by mass or less being more preferred.

[0069] Examples of compounds having an aromatic ring include styrene, benzyl (meth)acrylate, methylstyrene, vinyltoluene, tert-butoxystyrene, acetoxystyrene, styrene dimer, styrene trimer, and other styrene derivatives, and 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl (meth)acrylate. Among these, styrene, styrene derivatives, and benzyl (meth)acrylate are preferred, and styrene and styrene derivatives are more preferred.

[0070] Based on the total amount of the component (A), the proportion of structural units derived from styrene and / or styrene derivatives is preferably 30% by mass or more, or 40% by mass or more, or 45% by mass or more, or 50% by mass or more, from the viewpoint of excellent adhesion and resolution of a resist pattern, and is preferably 85% by mass or less, or 75% by mass or less, or 70% by mass or less, from the viewpoint of excellent developability.

[0071] The second monomer may include a compound having an alicyclic ring, and the proportion of this compound in component (A) may be 10 to 40% by mass based on the total mass of all monomer components.

[0072] Examples of the compound having an alicyclic ring include compounds having a group having one cyclic hydrocarbon group, such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group; compounds having a group having two or more cyclic hydrocarbon groups, such as a dicyclopentanyl group, a dicyclopentenyl group, an adamantyl group, and an isobornyl group; and derivatives thereof, such as (meth)acrylic acid esters.

[0073] The second monomer may include a compound having a hydroxy group. The proportion of this compound in component (A) is preferably 1 to 25% by mass, more preferably 1 to 10% by mass, and even more preferably 1 to 6% by mass, based on the total mass of all monomer components. Controlling this proportion within the above range is preferred from the viewpoint of excellent adhesion and resolution.

[0074] Examples of compounds having a hydroxy group include hydroxyalkyl(meth)acrylates, specifically 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 4-hydroxybutyl(meth)acrylate, and glycerin-based (meth)acrylates (for example, glycerin mono(meth)acrylate). These compounds are advantageous in that they are relatively easy to obtain and allow easy control of developability and adhesion.

[0075] The second monomer may include one or more compounds other than those described above, for example, (meth)acrylic acid alkyl esters (linear alkyl esters and cyclic alkyl esters) other than those described above, conjugated diene compounds other than those described above, polar monomers other than those described above (amino group-containing monomers, amide group-containing monomers, cyano group-containing monomers, epoxy group-containing monomers, etc.), crosslinkable monomers other than those described above, acid anhydrides other than those described above, and the like.

[0076] Component (A) may be synthesized by adding an appropriate amount of a radical polymerization initiator such as benzoyl peroxide or azoisobutyronitrile to a solution obtained by diluting the above-mentioned monomer with a solvent such as acetone, methyl ethyl ketone, or isopropanol, and then heating and stirring. Synthesis may be carried out while adding a portion of the mixture dropwise to the reaction solution, or after the reaction is complete, additional solvent may be added to adjust the concentration to the desired level. The synthesis method may be solution polymerization, living radical polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization.

[0077] The content of component (A), based on the total solids mass of the photosensitive resin composition, is preferably 10% by mass or more, or 20% by mass or more, or 25% by mass or more, or 30% by mass or more, or 35% by mass or more, or 40% by mass or more, or 45% by mass or more, or 50% by mass or more, or 55% by mass or more, or 60% by mass or more, from the viewpoint of edge fuse resistance, i.e., from the viewpoint of suppressing exudation of the photosensitive resin composition layer from the film edge surface, and is preferably 90% by mass or less, or 80% by mass or less, or 70% by mass or less, or 60% by mass or less, from the viewpoint of control of development time. Edge fuse resistance is sometimes particularly required when the photosensitive element is formed into a roll.

[0078] [Component (B): Compound Having an Ethylenically Unsaturated Bond] The compound having an ethylenically unsaturated bond, which is component (B), may include a compound having a bisphenol A skeleton. In the present disclosure, the compound having a bisphenol A skeleton also includes a compound having a hydrogenated bisphenol A skeleton. Examples of the compound having a bisphenol A skeleton include di(meth)acrylates having a bisphenol A skeleton. Examples of the di(meth)acrylates having a bisphenol A skeleton include those represented by the following general formula (I): (Wherein, two R 2 are each independently a hydrogen atom or a methyl group, and X 2 O and Y 2 O are each independently an oxyethylene group or an oxypropylene group, m3, m4, n2, and n3 are each independently an integer of 0 to 40, m3+m4 is 1 to 40, and n2+n3 is 0 to 20.

[0079] The content of the di(meth)acrylate having a bisphenol A skeleton is preferably 30% by mass or more, 60% by mass or more, or 80% by mass or more, based on the total solid content of the photosensitive resin composition, from the viewpoint of excellent adhesion and resolution of the resist pattern. The content of the compound may be 100% by mass or less, 99% by mass or less, or 90% by mass or less.

[0080] Component (B) preferably contains a compound having two or more ethylenically unsaturated bonds in one molecule. The photosensitive resin composition may further contain a compound having three, four, five, or six ethylenically unsaturated bonds in one molecule.

[0081] The component (B) preferably contains a compound containing a (meth)acryloyl group (hereinafter referred to as a (meth)acrylate compound), and more preferably contains a difunctional or higher functional (meth)acrylate compound, i.e., a (meth)acrylate compound having two or more (meth)acryloyl groups in one molecule. In a preferred embodiment, the component (B) is a (meth)acrylate compound. From the viewpoint of adhesion and flexibility of the resist pattern, the (meth)acrylate compound preferably contains a difunctional (meth)acrylate compound and a trifunctional or higher functional (meth)acrylate compound. The (meth)acrylate compound may contain a tetrafunctional, pentafunctional, or hexafunctional (meth)acrylate compound.

[0082] Examples of bifunctional (meth)acrylate compounds include alkyl di(meth)acrylate, 1,3-bis(meth)acryloyloxy-2-propanol, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, tricyclodecanol di(meth)acrylate, ethoxylated (hydrogenated) bisphenol A di(meth)acrylate, propoxylated (hydrogenated) bisphenol A di(meth)acrylate, and tetramethylene glycosylated (hydrogenated) bisphenol A di(meth)acrylate.

[0083] Commercially available bifunctional (meth)acrylate compounds include, for example, NK Ester (registered trademark) A-HD-N, A-NOD-N, A-DOD-N, A-NPG, 701A, A-200, A-400, A-600, A-1000, APG-200, APG-400, APG-700, A-PTMG65, A-DCP, ABE-300, A-BPE-4, A-BPE-10, A-BPE-20, HD-N, and NOD-N. , DOD-N, NPG, 701, 2G, 3G, 4G, 9G, 14G, 23G, 9PG, DCP, BPE-80N, BPE-100, BPE-200, BPE-500, BPE-900, BP E-1300N, NK Oligo (registered trademark) UA-4200, UA-160TM, UA-290TM, UA-W2A, UA-4400, UA-122P, U-200PA (manufactured by Shin-Nakamura Chemical Co., Ltd.), Litea Acrylate (registered trademark) 3EG-A, 4EG-A, 9EG-A, 14EG-A, PTMGA-250, NP-A, MPD-A, 1.6HX-A, 1.9ND-A, DCP-A, BP-4EAL, BP-4PA, HPP-A, Light Ester G-201P (all manufactured by Kyoeisha Chemical Co., Ltd.), Fancryl (registered trademark) FA-124AS, FA-023M, FA-121M, FA-124M, FA-125M, FA-12 9AS, FA-137M, FA-220M, FA-222A, FA-240A, FA-240M, FA-320M, FA-3218M, FA-321A, FA-321M, FA-324A, FA-731A, FA-P240A, FA-P270A, FA-PTG9A, FA-PTG9M, FA-PTG28A, FA-PTG49A (all manufactured by Resonac Co., Ltd.), DPGDA, HDDA, TPGDA, EBECRYL 145, EBECRYL 150, PEG400DA, EBECRYL 11, IRR 214-K, EBECRYL 130, EBECRYL PEG200DMA (all manufactured by Daicel Allnex Co., Ltd.), SR212, SR213, SR230, SR238F, SR259, SR268,SR272, SR306H, SR344, SR349, SR508, CD560, CD561, CD564, SR601, SR602, SR610, SR833S, SR9003, SR9045, SR9209, SR205, SR206, SR209, SR210, SR214, SR231, SR239, SR248, SR252, SR297, SR348, S Examples of such copolymers include R480, CD540, CD541, CD542, SR603, SR644, and SR9036 (all manufactured by Arkema Co., Ltd.), KAYARAD (registered trademark) NPGDA, KAYARAD PEG400DA, KAYARAD FM-400, KAYARAD R-167, KAYARAD HX-220, KAYARAD HX-620, KAYARAD R-551, KAYARAD R-712, KAYARAD R-604, and KAYARAD R-684 (all manufactured by Nippon Kayaku Co., Ltd.).

[0084] Examples of trifunctional or higher functional (meth)acrylate compounds include trimethylolpropane tri(meth)acrylate, glycerin tri(meth)acrylate, isocyanuric acid tri(meth)acrylate, pentaerythritol (tri / tetra)(meth)acrylate, ditrimethylolpropane (tetra / penta / hexa)(meth)acrylate, and dipentaerythritol (tetra / penta / hexa)(meth)acrylate.

[0085] Furthermore, examples of the trifunctional or higher functional (meth)acrylate compound include alkylene oxide-modified tri(meth)acrylate of trimethylolpropane, alkylene oxide-modified tri(meth)acrylate of glycerin, alkylene oxide-modified isocyanuric acid tri(meth)acrylate, alkylene oxide-modified pentaerythritol (tri / tetra)(meth)acrylate, alkylene oxide-modified ditrimethylolpropane (tetra / penta / hexa)(meth)acrylate, and alkylene oxide-modified dipentaerythritol (tetra / penta / hexa)(meth)acrylate.

[0086] Commercially available trifunctional or higher (meth)acrylate compounds include, for example, NK Ester (registered trademark) A-TMPT, A-TMPT-9EO, AT-20E, A-GLY-3E, A-GLY-9E, A-GLY-20E, A-9300, A-9200YN, A-TMM-3, A-TMM-3L, A-TMM-3LM-N, A-TMMT, ATM-35E, AD-TMP, A-DPH, and A-9550. A-DPH-12E, TPOA-50, NK Oligo (registered trademark) UA-7100, UA-1100H, U-6LPA, UA-33H, U-10HA, U-10PA, U-15HA (all manufactured by Shin-Nakamura Chemical Co., Ltd.), Light Acrylate (registered trademark) TMP-A, cPE-3A, PE-4A, DPE-6A (all manufactured by Kyoeisha Chemical Co., Ltd.), FA-731A (manufactured by Resonac Co., Ltd.), TMPTA, EBECRYL 160S, OTA 480, PETIA, PETRA, EBECRYL 40, PETA, EBECRYL 140, EBECRYL 1140, EBECRYL 1142, DPHA, EBECRYL 895, EBECRYL 896, EBECRYL Examples of the methyl methyl acrylate copolymer include TMPTMA (manufactured by Daicel Allnex Co., Ltd.), SR351S, SR368, SR415, SR444, SR454, SR492, SR499, CD501, SR502, SR9020, D9021, SR9035, SR295, SR355, SR399, SR494, and SR9041 (manufactured by Arkema Co., Ltd.), KAYARAD (registered trademark) GPO-303, TMPTA, THE-330, TPA-330, PET-30, T-1420(T), RP-1040, DPHA, DPEA-12, D-310, and DPCA-20 (manufactured by Nippon Kayaku Co., Ltd.).

[0087] The content of the tri- or higher functional (meth)acrylate compound may be 0 to 50% by mass, 0 to 25% by mass, or 1 to 15% by mass based on the total amount of the component (B).

[0088] Specifically, compounds that may be contained in component (B) include: dimethacrylate of polyethylene glycol in which an average of 5 mol of EO has been added to each end of bisphenol A (the above-mentioned "FA-321M," product name); dimethacrylate of polyethylene glycol in which an average of 2 mol of EO has been added to each end of bisphenol A; dimethacrylate of polyalkylene glycol in which an average of 3 mol of EO has been added to each end of polypropylene glycol having an average of 12 PO repeating units per molecule ("EO" is an abbreviation for ethylene oxide, and "PO" is an abbreviation for propylene oxide). In relation to the compound represented by the above general formula (I), for example, the above-mentioned "FA-321M" is a compound represented by R 2 = methyl group, X 2 It is expressed as follows: O = oxyethylene group, m3 + m4 = 10, n2 = n3 = 0.

[0089] The content of the component (B) is preferably 30% by mass or more, or 35% by mass or more, based on the total mass of the solid content of the photosensitive resin composition, from the viewpoints of sensitivity, tackiness, and tracking ability, and is preferably 50% by mass or less, or 45% by mass or less, or 42% by mass or less, from the viewpoints of edge fuse resistance, tackiness, and resolution.

[0090] From the viewpoints of edge fuse resistance, tackiness, and resolution, the ratio of the content of the component (B) to the content of the component (A) in the photosensitive resin composition (component (B) / component (A)) is preferably 1.4 or less, or 1.3 or less, or 1.2 or less, or 1.1 or less, and is preferably 0.6 or more, or 0.7 or more, or 0.8 or more, or 0.9 or more, or 1.0 or more.

[0091] The number of ethylenically unsaturated bonds in the photosensitive resin composition per 100 g of solids is preferably 0.10 mol or more, 0.11 mol or more, 0.12 mol or more, or 0.13 mol or more, from the viewpoint that the photosensitive resin component is less likely to elute from the cured resist pattern in the water-rinsing step after development, thereby reducing contamination in the water-rinsing step; and is preferably 0.30 mol or less, 0.28 mol or less, 0.25 mol or less, 0.22 mol or less, 0.20 mol or less, 0.18 mol or less, or 0.15 mol or less, from the viewpoint that the cured resist pattern is less likely to chip and fall off in the water-rinsing step after development, thereby reducing contamination in the water-rinsing step.

[0092] [Component (C): Photopolymerization Initiator and / or Sensitizer] The photopolymerization initiator and / or sensitizer of component (C) generates radicals when exposed to actinic rays, thereby initiating polymerization of a compound having an ethylenically unsaturated bond and / or exhibiting a sensitization effect. Examples of component (C) include (C-1) a biimidazole-based compound and (C-2) a photopolymerization initiator and / or sensitizer other than a biimidazole-based compound.

[0093] (C-1) Biimidazole Compounds) (C-1) Biimidazole compounds refer to compounds having a biimidazole structure, and examples thereof include lophine dimers, i.e., dimers of 2,4,5-triarylimidazole. Examples of biimidazole compounds include dimers of 2-(o-chlorophenyl)-4,5-diphenylimidazole (also known as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole), dimers of 2-(o-chlorophenyl)-4,5-bis-(m-methoxyphenyl)imidazole, dimers of 2-(p-methoxyphenyl)-4,5-diphenylimidazole, and 2,2',5-tris-(o-chlorophenyl)-4-(3,4-dimethoxyphenyl). 2,4-bis-(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole, 2,4,5-tris-(o-chlorophenyl)-diphenylbiimidazole, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-biimidazole, 2,2'-bis-(2-fluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis- (2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,4-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,5-difluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,6-difluorophenyl)-4,4',5,5'-tetrakis-(3-methylphenyl)-biimidazole 2,2'-bis-(2,3,4-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,5-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,4,2,2'-bis-(2,4,6-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,4,5-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, 2,2'-bis-(2,3,4,6-tetrafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, and 2,2'-bis-(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole.

[0094] From the viewpoints of high sensitivity, resolution, and adhesion, it is preferable that component (C) contains a lophine dimer, and among these, it is more preferable that it contains a dimer of 2-(o-chlorophenyl)-4,5-diphenylimidazole (also known as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole).

[0095] ((C-2) Photopolymerization initiators and / or sensitizers other than biimidazole-based compounds) Examples of (C-2) photopolymerization initiators and / or sensitizers other than biimidazole-based compounds include N-aryl-α-amino acid compounds, quinone compounds, aromatic ketone compounds, anthracene compounds, acetophenone compounds, acylphosphine oxide compounds, benzoin compounds, benzoin ether compounds, dialkyl ketal compounds, thioxanthone compounds, dialkylaminobenzoic acid ester compounds, oxime ester compounds, acridine compounds, N-arylamino acid ester compounds, halogen compounds, pyrazoline derivatives, anthracene derivatives, naphthalene derivatives, and oxazole derivatives.

[0096] Examples of N-aryl-α-amino acid compounds include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine. Among these, N-phenylglycine is preferred because of its high sensitizing effect.

[0097] Examples of quinone compounds include 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone, and 3-chloro-2-methylanthraquinone.

[0098] Examples of aromatic ketone compounds include benzophenone derivatives, such as benzophenone, Michler's ketone [4,4'-bis(dimethylamino)benzophenone], and 4-methoxy-4'-dimethylaminobenzophenone. From the viewpoints of sensitization effect and adhesion, examples of aromatic ketone compounds include 4,4'-bis(diethylamino)benzophenone.

[0099] The anthracene compound may be anthracene or a derivative thereof. Examples of the anthracene compound include anthracene, 9,10-dialkoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, and 10-phenyl-9-anthraceneboronic acid. From the viewpoints of sensitization effect and adhesion, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, and 10-phenyl-9-anthraceneboronic acid are preferred, and 9,10-diphenylanthracene is particularly preferred.

[0100] Examples of acetophenone compounds include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)-phenyl(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1. Commercially available acetophenone compounds include the Irgacure series (manufactured by Ciba Specialty Chemicals: Irgacure-907, Irgacure-369, and Irgacure-379, etc.).

[0101] Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phosphine oxide, and bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide. Commercially available acylphosphine oxide compounds include Lucirin TPO (manufactured by BASF) and Irgacure-819 (manufactured by Ciba Specialty Chemicals).

[0102] Examples of the benzoin compound and benzoin ether compound include benzoin, benzoin ethyl ether, benzoin phenyl ether, methylbenzoin, and ethylbenzoin.

[0103] Examples of dialkyl ketal compounds include benzyl dimethyl ketal and benzyl diethyl ketal. Examples of thioxanthone compounds include 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, and 2-chlorothioxanthone. Examples of dialkylaminobenzoate compounds include ethyl dimethylaminobenzoate, ethyl diethylaminobenzoate, ethyl-p-dimethylaminobenzoate, and 2-ethylhexyl-4-(dimethylamino)benzoate.

[0104] Examples of oxime ester compounds include 1-phenyl-1,2-propanedione-2-O-benzoyloxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, etc. Commercially available oxime ester compounds include CGI-325, Irgacure-OXE01, and Irgacure-OXE02 (all manufactured by Ciba Specialty Chemicals).

[0105] As the acridine compound, 1,7-bis(9,9'-acridinyl)heptane or 9-phenylacridine is preferred in terms of sensitivity, resolution, availability, etc.

[0106] Examples of the ester compound of N-arylamino acid include methyl ester of N-phenylglycine, ethyl ester of N-phenylglycine, n-propyl ester of N-phenylglycine, isopropyl ester of N-phenylglycine, 1-butyl ester of N-phenylglycine, 2-butyl ester of N-phenylglycine, tert-butyl ester of N-phenylglycine, pentyl ester of N-phenylglycine, hexyl ester of N-phenylglycine, pentyl ester of N-phenylglycine, and octyl ester of N-phenylglycine.

[0107] Examples of halogen compounds include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzyl bromide, methylene bromide, tribromomethylphenylsulfone, carbon tetrabromide, tris(2,3-dibromopropyl)phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, chlorinated triazine compounds, and diaryliodonium compounds. Among these, tribromomethylphenylsulfone is preferred.

[0108] Examples of pyrazoline derivatives include 1-phenyl-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-(4-(benzoxazol-2-yl)phenyl)-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-octyl-phenyl)-pyrazoline, 1-phenyl-3-(4-isopropylstyryl)-5-(4-isopropylphenyl)-pyrazoline, 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)- From the above viewpoints, pyrazoline, 1-phenyl-3-(3,5-dimethoxystyryl)-5-(3,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(3,4-dimethoxystyryl)-5-(3,4-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,6-dimethoxystyryl)-5-(2,6-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,5-dimethoxystyryl)-5-(2,5-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,3-dimethoxystyryl)-5-(2,3-dimethoxyphenyl)-pyrazoline, 1-phenyl-3-(2,4-dimethoxystyryl)-5-(2,4-dimethoxyphenyl)-pyrazoline, and the like are preferred. From the viewpoints of adhesion and rectangularity of the resist pattern, the pyrazoline derivatives preferably include 1-phenyl-3-(4-tert-butylstyryl)-5-(4-tert-butylphenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-butylphenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-octylphenyl)-pyrazoline, and 1-phenyl-3-(4-methoxystyryl)-5-(4-methoxyphenyl)-pyrazoline. Of these, 1-phenyl-3-(4-biphenyl)-5-(4-tert-butylphenyl)-pyrazoline is more preferred.

[0109] Examples of naphthalene derivatives include 1-methoxynaphthalene, 1-ethoxynaphthalene, 1-propoxynaphthalene, 1-butoxynaphthalene, 1,4-dimethoxynaphthalene, 1-ethoxy-4-methoxynaphthalene, 1,4-diethoxynaphthalene, 1,4-bis(n-butoxy)naphthalene, 1,4-bis(i-butoxy)naphthalene, 1,4-bis(n-pentyloxy)naphthalene, 1,4-bis(n-hexyloxy)naphthalene, and 1,4-bis(n-heptyloxy)naphthalene. Examples of the naphthalene derivative include 1,4-dibenzyloxynaphthalene, 1,4-diphenethyloxynaphthalene, 1,4-diglycidyloxynaphthalene, 1,4-bis(2-methylglycidyloxy)naphthalene, 1-naphthol, 2-naphthol, 1-(2-hydroxyethoxy)naphthalene, and 2-(2-hydroxyethoxy)naphthalene. Of these, 1,4-diethoxynaphthalene is preferred as the naphthalene derivative.

[0110] Examples of oxazole derivatives include 5-tert-butyl-2-[5-(5-tert-butyl-1,3-benzoxazol-2-yl)thiophen-2-yl]-1,3-benzoxazole and 2-[4-(1,3-benzoxazol-2-yl)naphthalen-1-yl]-1,3-benzoxazole.

[0111] From the viewpoints of peelability, sensitivity, resolution, and adhesion, the photopolymerization initiator and / or sensitizer (C-2) other than a biimidazole-based compound preferably includes a compound having at least one skeleton selected from the group consisting of pyrazoline derivatives, anthracene derivatives, benzophenone derivatives, naphthalene derivatives, and oxazole derivatives.

[0112] The content of component (C) is preferably 0.01 to 20 mass %, more preferably 0.5 to 10 mass %, based on the total solids content of the photosensitive resin composition. By adjusting the content of component (C) within the above range, good sensitivity can be obtained and light can be easily transmitted to the bottom of the photosensitive resin composition layer, thereby realizing high resolution.

[0113] The component (C) preferably includes a biimidazole compound (C-1). The content of the biimidazole compound, based on the total solid content of the photosensitive resin composition, is preferably 3% by mass or more, 4% by mass or more, 5% by mass or more, or 6% by mass or more from the viewpoint of obtaining a favorable radical generating effect, and in one aspect, may be 10% by mass or less, or 8% by mass or less from the viewpoint of reducing the amount of foreign matter in the photosensitive resin composition.

[0114] When the component (C) includes the biimidazole-based compound (C-1), the content of the photopolymerization initiator and / or sensitizer other than the biimidazole-based compound (C-2) may be 0.01 to 2.0 mass %, or may be 0.05 to 1.0 mass %, based on the total solids content of the photosensitive resin composition. In this case, good sensitivity can be obtained and light can be easily transmitted to the bottom of the photosensitive resin composition layer, thereby realizing high resolution.

[0115] In a preferred embodiment, the photosensitive resin composition layer comprises (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, and (C) a polymerization initiator and / or a sensitizer, wherein the component (A) comprises, based on the total amount of the component (A), 15% by mass to 65% by mass of structural units derived from (meth)acrylic acid and 30% by mass to 85% by mass of structural units derived from styrene and / or a styrene derivative, the component (B) comprises 15% by mass or more of a di(meth)acrylate having a bisphenol A skeleton, based on the total solids content of the photosensitive resin composition layer, and the component (C) comprises 3% by mass or more of a compound having a biimidazole structure, based on the total solids content of the photosensitive resin composition layer, and includes a compound having a skeleton of at least one derivative selected from the group consisting of pyrazoline derivatives, anthracene derivatives, naphthalene derivatives, and oxazole derivatives.

[0116] [Other Components] The photosensitive resin composition may contain, if desired, antioxidants, stabilizers, leuco dyes, base dyes, color-forming dyes, plasticizers, hindered amines, and the like.

[0117] Examples of the antioxidant include triphenyl phosphite (e.g., manufactured by ADEKA under the trade name of TPP), tris(2,4-di-tert-butylphenyl) phosphite (e.g., manufactured by ADEKA under the trade name of 2112), tris(mononylphenyl) phosphite (e.g., manufactured by ADEKA under the trade name of 1178), and bis(mononylphenyl)-dinonylphenyl phosphite (e.g., manufactured by ADEKA under the trade name of 329K).

[0118] The content of the antioxidant in the photosensitive resin composition is preferably 0.01 to 0.8% by mass, and more preferably 0.01 to 0.3% by mass, based on the total solid content in the photosensitive resin composition. The content of the antioxidant is preferably equal to or greater than the lower limit described above, from the viewpoints of achieving good hue stability of the resist pattern and improving the sensitivity of the photosensitive resin composition layer. On the other hand, the content of the antioxidant is preferably equal to or less than the upper limit described above, from the viewpoints of achieving good hue stability while suppressing the color development of the resist pattern and improving adhesion.

[0119] The stabilizer may be, for example, at least one compound selected from the group consisting of radical polymerization inhibitors, benzotriazoles, and alkylene oxide compounds having a glycidyl group.

[0120] Examples of radical polymerization inhibitors include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, 4-tert-butylcatechol, phenothiazine, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], nitrosophenylhydroxyamine aluminum salt (e.g., aluminum salt with 3 moles of nitrosophenylhydroxylamine added), and diphenylnitrosamine. Among these, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate] or aluminum salt with 3 moles of nitrosophenylhydroxylamine added is preferred.

[0121] Examples of benzotriazoles include 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-tolyltriazole, and bis(N-2-hydroxyethyl)aminomethylene-1,2,3-benzotriazole.

[0122] The benzotriazoles are preferably compounds having a carboxy group, and examples thereof include 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, N-(N,N-di-2-ethylhexyl)aminomethylenecarboxybenzotriazole, N-(N,N-di-2-hydroxyethyl)aminomethylenecarboxybenzotriazole, and N-(N,N-di-2-ethylhexyl)aminoethylenecarboxybenzotriazole, and a 1:1 mixture of 1-(2-di-n-butylaminomethyl)-5-carboxylbenzotriazole and 1-(2-di-n-butylaminomethyl)-6-carboxylbenzotriazole. Among these, 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, and a 1:1 mixture of 1-(2-di-n-butylaminomethyl)-5-carboxylbenzotriazole and 1-(2-di-n-butylaminomethyl)-6-carboxylbenzotriazole are preferred.

[0123] Examples of alkylene oxide compounds having a glycidyl group include neopentyl glycol diglycidyl ether (e.g., Epolite 1500NP manufactured by Kyoeisha Chemical Co., Ltd.), nonaethylene glycol diglycidyl ether (e.g., Epolite 400E manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A-propylene oxide 2-mol adduct diglycidyl ether (e.g., Epolite 3002 manufactured by Kyoeisha Chemical Co., Ltd.), and 1,6-hexanediol diglycidyl ether (e.g., Epolite 1600 manufactured by Kyoeisha Chemical Co., Ltd.).

[0124] The total content of the stabilizers in the photosensitive resin composition is preferably 0.001 to 3 mass %, more preferably 0.05 to 1 mass %, based on the total solid content in the photosensitive resin composition. The total content is preferably equal to or greater than the above lower limit from the viewpoint of imparting good storage stability to the photosensitive resin composition, and is preferably equal to or less than the above upper limit from the viewpoint of maintaining the sensitivity of the photosensitive resin composition layer.

[0125] Examples of base dyes include Diamond Green [CAS Number (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, trade name, manufactured by Hodogaya Chemical Co., Ltd.), Fuchsin [632-99-5], Methyl Violet [603-47-4], Methyl Green [82-94-0], Victoria Blue B [2580-56-5], Basic Blue 7 [2390-60-5] (e.g., Aizen Victoria Pure Blue BOH, trade name, manufactured by Hodogaya Chemical Co., Ltd.), Rhodamine B [81-88-9], Rhodamine 6G [989-38-8], Basic Yellow 2 [2465-27-2], etc. Among these, Diamond Green is preferred from the viewpoint of improving colorability, hue stability, and exposure contrast.

[0126] The content of the base dye in the photosensitive resin composition is preferably 0.001 to 3 mass %, more preferably 0.01 to 2 mass %, and even more preferably 0.04 to 1 mass %, based on the total mass of solids in the photosensitive resin composition. From the viewpoint of obtaining good colorability, the content of the base dye is preferably equal to or greater than the above-mentioned lower limit, while from the viewpoint of maintaining the sensitivity of the photosensitive resin composition layer, the content is preferably equal to or less than the above-mentioned upper limit.

[0127] Known examples of color-forming dyes include combinations of leuco dyes and halogen compounds. Examples of leuco dyes include tris(4-dimethylamino-2-methylphenyl)methane [leuco crystal violet] and tris(4-dimethylamino-2-methylphenyl)methane [leucomalachite green]. Examples of halogen compounds include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzal bromide, methylene bromide, tribromomethylphenyl sulfone, carbon tetrabromide, tris(2,3-dibromopropyl)phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and hexachloroethane. Examples of leuco dyes that may be used include the aforementioned leuco crystal violet and those known as diamond green.

[0128] Examples of additives such as plasticizers include phthalate esters such as diethyl phthalate, o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, triethyl acetylcitrate, tri-n-propyl acetylcitrate, tri-n-butyl acetylcitrate, polypropylene glycol, polyethylene glycol, polyethylene glycol alkyl ether, and polypropylene glycol alkyl ether.

[0129] Examples of the hindered amine compound include 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethyl-1-hydroxypiperidine, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6-tetramethyl-1-oxypiperidine, 2,2,6,6-tetramethylpiperidyl methacrylate, and 1,2,2,6,6-pentamethylpiperidyl methacrylate. From the viewpoint of improving the flexibility of the cured film after the crosslinking reaction and improving the releasability, it is preferable that the hindered amine compound has a monofunctional polymerizable group, and 2,2,6,6-tetramethylpiperidyl methacrylate and 1,2,2,6,6-pentamethylpiperidyl methacrylate are particularly preferred.

[0130] The proportion of the hindered amine compound relative to the total solid mass of the photosensitive resin composition is preferably 0.001 to 10% by mass. From the viewpoint of excellent releasability, this proportion is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.1% by mass or more, and particularly preferably 0.3% by mass or more. On the other hand, from the viewpoint of improving resolution, this proportion is preferably 5% by mass or less, more preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less. The above hindered amine compound may be used as a repeating unit in component (A).

[0131] In this embodiment, the transmittance of the photosensitive resin composition layer at a wavelength of 365 nm when the layer is 25 μm thick is preferably 45% or more, and more preferably 60% or more. In one aspect, the transmittance may be 90% or less from the viewpoint of ease of manufacturing the photosensitive resin composition layer. The transmittance of the photosensitive resin composition layer at a wavelength of 365 nm when the layer is 25 μm thick can be controlled, for example, by the content and / or type of photopolymerization initiator. For example, reducing the content of the photopolymerization initiator and / or using a photopolymerization initiator with a low absorption coefficient at a wavelength of 365 nm tends to increase the transmittance.

[0132] <Prepared Solution of Photosensitive Resin Composition> A prepared solution for producing a photosensitive element may be prepared by adding a solvent to the photosensitive resin composition. Examples of the solvent include ketones such as acetone and methyl ethyl ketone (MEK), and alcohols such as methanol, ethanol, and isopropyl alcohol. In one embodiment, the solvent can be added to the photosensitive resin composition so that the viscosity of the prepared solution is 500 to 4000 mPa·sec at 25°C.

[0133] <Protective Film> The photosensitive element may further include a protective film. The protective film may be disposed on the surface of the photosensitive resin composition layer opposite the support film. When the adhesion strength between the photosensitive resin composition layer and the protective film is sufficiently smaller than the adhesion strength between the photosensitive resin composition layer and the support film, the protective film can be easily peeled off from the photosensitive resin composition layer. Preferred examples of the protective film include polyethylene film, polypropylene film, oriented polypropylene film, and polyester film.

[0134] A release layer can be provided on the surface of the protective film so that the protective film can be easily peeled off from the photosensitive resin composition layer. Release layers are classified into silicone compounds and non-silicone compounds, for example.

[0135] Examples of silicone compounds include condensation reaction type silicone resins obtained by reacting polydimethylsiloxane having silanol ends with polymethylhydrogensiloxane or polymethylmethoxysiloxane; addition reaction type silicone resins obtained by reacting a dimethylsiloxane-methylvinylsiloxane copolymer or a dimethylsiloxane-methylhexenylsiloxane copolymer with polymethylhydrogensiloxane; ultraviolet-curable or electron-beam-curable silicone resins obtained by curing acrylic silicone, epoxy group-containing silicone, or the like with ultraviolet light or electron beam; and modified silicone resins such as epoxy-modified silicone resin (silicone epoxy), polyester-modified silicone resin (silicone polyester), acrylic-modified silicone resin (silicone acrylic), phenol-modified silicone resin (silicone phenol), alkyd-modified silicone resin (silicone alkyd), and melamine-modified silicone resin (silicone melamine).

[0136] Examples of non-silicone compounds include alkyd resins, long-chain alkyl resins, acrylic resins, and polyolefin resins.

[0137] The film thickness of the release layer is preferably 0.001 to 2 μm, more preferably 0.005 to 1 μm, and even more preferably 0.01 to 0.5 μm. If the film thickness is equal to or less than the upper limit, the coating film tends to have a good appearance and the coating film tends to be sufficiently cured. On the other hand, if the film thickness is equal to or greater than the lower limit, sufficient releasability tends to be ensured.

[0138] The thickness of the protective film is preferably 10 to 100 μm, more preferably 10 to 50 μm. Examples of the protective film include Alphan (registered trademark) EM-501, E-200, E-201F, FG-201, and MA-411 (all manufactured by Oji F-Tex Co., Ltd.), Torayfan (registered trademark) KW37, 2578, 2548, 2500, and YM17S, Therapeel (registered trademark) PJ271, PJ111, HP2, PJ101, WZ, MDA, MFA, TK07, BKE, BX8A, and SY (all manufactured by Toray Industries, Inc.), and GF-18, GF-818, and GF-858 (all manufactured by Tamapoly Co., Ltd.).

[0139] <<Production of Photosensitive Element>> The photosensitive element can be produced by laminating a photosensitive resin composition layer and, if necessary, a protective film on a support film. In one embodiment, the method for producing a photosensitive film includes the steps of: mixing the photosensitive resin composition with a solvent that dissolves the photosensitive resin composition to obtain a photosensitive resin composition preparation (coating liquid); applying the coating liquid to the support film using a bar coater or a roll coater and drying the coating liquid to form a photosensitive resin composition layer on the support film; and, if necessary, laminating a protective film on the photosensitive resin composition layer.

[0140] The photosensitive element may be wound into a roll. The roll may or may not have a core. The long photosensitive element may be wound around a core, or may be wound without a core.

[0141] <<Formation of Resist Pattern>> A resist pattern can be formed using the photosensitive element of the present embodiment. In one aspect, a method for producing a resist pattern includes: a step of laminating a photosensitive element on a substrate (laminating step); a step of exposing the photosensitive resin composition layer in the laminated photosensitive element (exposing step); and a step of developing the photosensitive resin composition layer after exposure (developing step).

[0142] <Lamination Step> In the lamination step, if the photosensitive element has a protective film, this is peeled off, and then the photosensitive resin composition layer is laminated once or multiple times using a laminator by thermocompression bonding to the surface of a support (e.g., substrate). Examples of materials for the substrate include copper, stainless steel (SUS), glass, and indium tin oxide (ITO). The heating temperature during lamination is, for example, 40°C to 160°C. Thermocompression bonding can be performed using a laminator equipped with rolls, or by repeatedly passing the laminate of the substrate and the photosensitive resin composition layer through the rolls several times. Thermocompression bonding can be performed in a reduced pressure environment, if desired.

[0143] <Exposure Step> In the exposure step, the photosensitive resin composition layer is exposed to actinic light using an exposure machine. The exposure can be performed after peeling off the support film as desired, or can be performed without peeling off the support film. When exposure is performed through a photomask, the exposure amount is determined by the illuminance of the light source and the exposure time, which may be measured using an actinometer. In the exposure step, direct imaging exposure may be performed. In direct imaging exposure, exposure is performed directly on the substrate using a drawing device without using a photomask. A semiconductor laser or an ultra-high pressure mercury lamp with a wavelength of 350 to 410 nm is used as the light source. When the drawing pattern is controlled by a computer, the exposure amount is determined by the illuminance of the exposure light source and the moving speed of the substrate.

[0144] The light irradiation method used in the exposure step is preferably at least one method selected from the group consisting of a projection exposure method, a proximity exposure method, a contact exposure method, a direct imaging exposure method, and an electron beam direct writing method, and is more preferably a projection exposure method or a direct imaging exposure method.

[0145] A heating step may be performed between the exposure step and the development step. The heating temperature is preferably about 30 to about 200°C, more preferably 30 to 150°C, and even more preferably 35 to 120°C. By performing the heating step, it is easy to improve the resolution and adhesion. Examples of heating methods include a heating furnace using hot air, infrared, or far-infrared rays, as well as a thermostatic bath, a hot plate, a hot air dryer, an infrared dryer, a hot roll, and the like.

[0146] The time elapsed from the exposure step to the heating step, for example, the time elapsed from the time exposure is stopped to the time heating is started, is preferably 10 to 600 seconds, more preferably 20 to 300 seconds. The time elapsed from the time heating is started to the time heating is stopped is preferably 1 to 120 seconds, more preferably 5 to 60 seconds.

[0147] <Developing Step> In the developing step, the uncured portions of the photosensitive resin composition layer after exposure (unexposed portions in the case of a negative type) are removed with a developer using a developing device. After exposure, if there is a support film on the photosensitive resin composition layer, this is peeled off. Subsequently, the exposed portions are developed (removed) using a developer containing an alkaline aqueous solution, thereby obtaining a resist image (resist pattern).

[0148] The alkaline aqueous solution is preferably an aqueous solution of Na2CO3, K2CO3, tetramethylammonium hydroxide, or the like. The alkaline aqueous solution is selected according to the properties of the photosensitive resin composition layer, and examples thereof include an aqueous Na2CO3 solution with a concentration of 0.2 to 2 mass %. The alkaline aqueous solution may contain a surfactant, an antifoaming agent, a small amount of an organic solvent to promote development, and the like. The temperature of the developer in the development step is preferably maintained within a range of 20 to 40°C.

[0149] <Washing Step> After the development step, it is preferable to carry out a washing step to remove the developer contained in the resist pattern. For example, the developer may be removed using washing water. The washing water may be selected according to the properties of the photosensitive resin composition layer, such as pure water or industrial water, and may contain 0.001 to 1 mass % of a polyvalent metal salt such as MgSO4, for example, from the viewpoint of improving the resolution and rectangularity of the resist pattern. The temperature of the washing water in the washing step is preferably maintained within the range of 20 to 40°C.

[0150] <Heating Step> After obtaining the resist pattern, if desired, a step of heating the resist pattern at 60°C to 300°C (heating step) may be carried out. By carrying out this heating step, the chemical resistance of the resist pattern is easily improved. For the heating step, a heating furnace using hot air, infrared rays, or far infrared rays may be used.

[0151] <<Manufacturing of Wiring Boards>> A wiring board can also be manufactured using the photosensitive element of the present embodiment. In one aspect, the method for manufacturing a wiring board includes: a conductor pattern forming step of etching or plating a substrate on which a resist pattern has been formed to form a conductor pattern; and a peeling step of peeling the resist pattern from the substrate.

[0152] <Conductive Pattern Forming Process> If necessary, a process (etching or plating process) may be performed on the substrate on which the resist pattern has been formed as described above. This allows a wiring pattern (conductor pattern) corresponding to the resist pattern to be formed on the substrate. For example, a metal plate or a metal-coated insulating plate may be used as the substrate, and after a resist pattern is formed on the substrate by the above-described method, a desired conductor pattern may be manufactured. An etching or plating process is performed on the substrate surface (e.g., copper surface) exposed by the above-described development. The etching process is performed, for example, by spraying an etching solution onto the resist pattern and the substrate surface. Examples of etching methods include acid etching and alkaline etching. Examples of etching solutions include a hydrochloric acid aqueous solution, a ferric chloride aqueous solution, or a mixture thereof. The plating process is performed by metal plating (e.g., metal plating with a copper sulfate plating solution) or solder plating the substrate portion exposed by the above-described development according to a known plating method.

[0153] <Removal Step> After producing a conductive pattern by the above method, a step (removal step) may be performed in which the resist pattern is removed from the substrate using an aqueous solution that is more alkaline than the developer. This allows for the production of a wiring board (e.g., a printed wiring board) having a desired conductive pattern. Examples of the alkaline aqueous solution for removal (hereinafter also referred to as "removal solution") include a 2 to 5 mass % aqueous solution of NaOH or KOH, or an organic amine-based stripper solution. A small amount of water-soluble solvent may be mixed into the stripper. Examples of the water-soluble solvent include alcohol. The temperature of the stripper solution in the stripping step is preferably within the range of 40 to 70°C.

[0154] <<Uses of Photosensitive Element>> The photosensitive element may be used in the manufacture of printed wiring boards; the manufacture of lead frames for mounting IC chips; precision processing of metal foils such as the manufacture of metal masks; the manufacture of packages such as ball grid arrays (BGA) and chip size packages (CSP); the manufacture of tape substrates such as chip-on-film (COF) and tape automated bonding (TAB); the manufacture of semiconductor bumps; and the manufacture of partition walls of flat panel displays such as ITO electrodes, address electrodes, and electromagnetic wave shields.

[0155] Next, exemplary embodiments of the present invention will be further described with reference to examples, but the present invention is not limited to these examples.

[0156] Examples 1 to 15, Comparative Examples 1 to 15: Production of Photosensitive Elements Preparation of Support Films Support films shown in Table 1 were prepared. For development products A to J, a non-commercially available polyester (special resin) was used for the main layer. For each support film, three lots with a roll length of at least 1000 m were prepared, and the number of foreign particles was determined for each lot according to inspection method B described below. The number of foreign particles for each lot is the average of the measurements taken at the front and rear ends of the lot. For development products A to H and J, the number of foreign particles with a major diameter of 5 μm to 30 μm was 0.0004 particles / mm 2 For developed product I, the number of foreign particles with a major axis of 5 μm to 30 μm was 0.0004 pieces / mm 2 The above selected lots were used as samples for Test Method A and Test Method C, which will be described later.

[0157] <Synthesis of Alkali-Soluble Polymers> Components A-1 to A-5 in Table 2 were synthesized by the following procedure. [A-1] 25 parts by mass of methacrylic acid, 25 parts by mass of styrene, 50 parts by mass of benzyl methacrylate, and 0.8 parts by mass of azobisisobutyronitrile were mixed to prepare solution (a). 200 g of methyl ethyl ketone and 100 g of ethanol were placed in a flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel, and nitrogen gas inlet tube. The mixture was stirred while blowing nitrogen gas into the flask, and the mixture in the flask was heated to 80°C. 300 g of solution (a) was added dropwise to the mixture in the flask at a constant dropping rate over 4 hours, and the mixture was then stirred at 80°C for 2 hours. Next, solution (b) was prepared by dissolving 0.5 parts by mass of azobisisobutyronitrile in 50 parts by mass of a mixture of 30 parts by mass of methyl ethyl ketone and 20 parts by mass of ethanol. 50 g of the solution (b) was added dropwise to the solution in the flask at a constant rate over 10 minutes, and then the mixture was stirred at 80°C for 3 hours. The solution in the flask was further heated to 90°C over 30 minutes and then maintained at 90°C for 2 hours. Stirring was then stopped, and the mixture was cooled to room temperature (25°C). This yielded a solution of alkali-soluble polymer A-1.

[0158] [A-2] An alkali-soluble polymer A-2 was synthesized in the same manner as in [A-1], except that in the preparation of solution (a), 25 parts by mass of methacrylic acid, 25 parts by mass of styrene, and 50 parts by mass of benzyl methacrylate were changed to 25 parts by mass of methacrylic acid, 60 parts by mass of styrene, 5 parts by mass of butyl acrylate, and 10 parts by mass of methyl methacrylate, thereby obtaining a solution of alkali-soluble polymer A-2.

[0159] [A-3] An alkali-soluble polymer A-3 was synthesized in the same manner as in [A-1], except that in the preparation of solution (a), 25 parts by mass of methacrylic acid, 25 parts by mass of styrene, and 50 parts by mass of benzyl methacrylate were changed to 27 parts by mass of methacrylic acid, 39 parts by mass of styrene, 4 parts by mass of 2-hydroxyethyl methacrylate, and 30 parts by mass of benzyl methacrylate, thereby obtaining a solution of alkali-soluble polymer A-3.

[0160] [A-4] An alkali-soluble polymer A-4 was synthesized in the same manner as in [A-1], except that in the preparation of solution (a), 25 parts by mass of methacrylic acid, 25 parts by mass of styrene, and 50 parts by mass of benzyl methacrylate were changed to 20 parts by mass of methacrylic acid, 45 parts by mass of styrene, 25 parts by mass of butyl acrylate, and 10 parts by mass of 2-ethylhexyl methacrylate, thereby obtaining a solution of alkali-soluble polymer A-4.

[0161] [A-5] An alkali-soluble polymer A-5 was synthesized in the same manner as in [A-1], except that in the preparation of solution (a), 25 parts by mass of methacrylic acid, 25 parts by mass of styrene, and 50 parts by mass of benzyl methacrylate were changed to 21 parts by mass of methacrylic acid, 39 parts by mass of styrene, and 40 parts by mass of methyl methacrylate, thereby obtaining a solution of alkali-soluble polymer A-5.

[0162] The weight average molecular weight of the alkali-soluble polymer was determined by measurement by gel permeation chromatography (GPC) and conversion using a calibration curve of standard polystyrene. The GPC conditions are as follows: (GPC conditions) Pump: PU-980 manufactured by JASCO Column: Two columns (Shodex KF-80Y / KF-806M) Eluent: Tetrahydrofuran Measurement temperature: 40°C Flow rate: 2.05 mL / min Detector: RI-1530 manufactured by JASCO

[0163] <Preparation of Photosensitive Resin Composition Preparation> Stepper-A, DI-B, Stepper-C, or DI-D (where the numbers for each component in the table indicate parts by mass based on the solid content) in the formulation shown in Table 2 and a solvent (ethanol) were stirred and mixed to a solid content of 60 mass %. This yielded a preparation containing a photosensitive resin composition.

[0164] <Lamination> The above-mentioned preparation was uniformly applied to the surface of a support film using a bar coater, and then dried in a dryer at 95°C for 3 minutes to form a photosensitive resin composition layer with a film thickness of 7 to 40 µm. The thickness of the photosensitive resin layer was adjusted to the target thickness by adjusting the spacer of the coater. Next, a 19 µm thick polyethylene film (GF-818, manufactured by Tamapoly Co., Ltd.) was laminated as a protective film onto the surface of the photosensitive resin composition layer on the side on which the support film was not laminated. This resulted in a photosensitive element.

[0165] <Evaluation> <Support Film> [Foreign Matter Evaluation: Inspection Method A] (Number of Foreign Matter) The support film alone was used for evaluation. Using a foreign matter removal roller, adhering foreign matter was thoroughly removed from both surfaces of the support film. Using an optical microscope (Nikon Corporation, MEASURING MICROSCOPE MM-800), the number of foreign matters inside the support film was measured. For substances that appeared black when observed with transmitted light, a 50x objective lens (Nikon Objectiv TU Plan ELWD 50x, lens numerical aperture 0.6), and a 10x eyepiece magnification, the illumination was switched and observation was performed with incident light to confirm whether the foreign matter was located inside the film. Only the foreign particles inside the film were observed one by one using an objective lens magnification of 50x (Nikon Objektiv TU Plan ELWD 50x, lens numerical aperture 0.6) and an eyepiece magnification of 10x, and the major diameter was measured. For foreign particles in which voids were visible, the major diameter including the void was measured, and for foreign particles in which voids were not visible, the maximum diameter of the outline was measured. Nine locations in an area of ​​160 mm x 210 mm were inspected, and the total number of foreign particles in the nine locations was obtained for major diameters of 5 μm to 30 μm and 10 μm to 20 μm. The total number of foreign particles was calculated based on the total inspection area (160 mm x 210 mm x 9 = 302,400 mm 2 ) divided by the number of foreign particles (pieces / mm 2 ) was calculated as follows.

[0166] (Ratio of Special Foreign Matter) For each of the foreign matter with a major axis of 5 μm to 30 μm and foreign matter with a major axis of 10 μm to 20 μm detected above, those for which no voids were visually confirmed were counted as special foreign matter. The ratio (%) of special foreign matter to 100% of foreign matter with a major axis of 5 μm to 30 μm, and the ratio (%) of the number of special foreign matter to 100% of foreign matter with a major axis of 10 μm to 20 μm were calculated as the ratio of special foreign matter.

[0167] [Foreign Matter Evaluation: Inspection Method B] The support film alone was subjected to evaluation. Adhering foreign matter was thoroughly removed from both surfaces of the support film using a foreign matter removal roller. The number of foreign matters inside the support film was measured using a Keyence 64-megapixel black-and-white camera (CA HF6400M) equipped with a VS Technology objective lens (VS-LTC7-50CO-28 / F). The binarization conditions were set as follows: upper limit 255, lower limit 90, maximum area 5000, minimum area 150, major / minor axis length ratio 4.0, and circularity 0.3. The coordinates of foreign matters detected using transmitted light were registered. The detected foreign matters were observed using coaxial incident light with a 50x objective lens (Nikon Objektiv TU Plan ELWD 50x, lens numerical aperture 0.6) to confirm whether the foreign matter was located inside the film. The major axis was measured only for foreign matter located inside the film. For foreign matter in which voids were visually recognized, the major axis including the void was measured, and for foreign matter in which voids were not visually recognized, the maximum diameter of the outline was measured. Nine locations in an area of ​​160 mm x 210 mm were inspected, and the total number of foreign matter in the nine locations was obtained for major axes of 5 μm to 30 μm and 10 μm to 20 μm. The total number of foreign matter was calculated based on the total inspection area (160 mm x 210 mm x 9 = 302,400 mm 2 ) divided by the number of foreign particles (pieces / mm 2 ) was calculated as follows.

[0168] (Ratio of Special Foreign Matter) The foreign matter having a major axis of 5 μm to 30 μm and the foreign matter having a major axis of 10 μm to 20 μm detected above were each observed using an objective lens magnification of 50x (Nikon Objektiv TU Plan ELWD 50x, lens numerical aperture 0.6), and those for which no voids were visually observed were counted as special foreign matter. The ratio (%) of special foreign matter to 100% of foreign matter having a major axis of 5 μm to 30 μm, and the ratio (%) of the number of special foreign matter to 100% of foreign matter having a major axis of 10 μm to 20 μm were calculated as the ratio of special foreign matter.

[0169] [Evaluation of Fine Particles: Test Method C] A support film peeled from a prepared photosensitive element was used. Adhering foreign matter was thoroughly removed from both surfaces of the support film using a foreign matter removal roller. The number of fine particles on the support film was measured using an optical microscope (Nikon Corporation, MEASURING MICROSCOPE MM-800). Measurements were performed using incident light through a polarizing filter, an objective lens magnification of 20x, an eyepiece magnification of 10x, and 80% of the maximum light intensity. The support film was placed on a plate with a 0.75 mm x 11 mm hole, and the number of fine particles within the hole was measured. Observation was performed while changing the focus to measure the number of fine particles throughout the thickness of the support film. A monitor was also installed on the optical microscope, and the diameter of the fine particles was measured. Measurements were performed using a monitor (Nikon Corporation, DIGITAL SIGHT DS-L2) with an objective lens magnification of 50x and an eyepiece magnification of 10x. The longest width (i.e., major axis) of a microparticle was taken as the diameter of the microparticle, even when the microparticle was not a perfect sphere. After repeating the measurement at 10 different arbitrary locations, the number average number of microparticles at 10 locations was calculated for each of the major axis sizes of 1.5 μm or more and less than 4.5 μm, 4.5 μm or more and less than 10 μm, and 10 μm or more.

[0170] [Arithmetic Mean Roughness Ra] The arithmetic mean roughness was calculated using a laser microscope by the following method for the uncoated surface (the surface not in contact with the photosensitive resin composition layer) of the support film peeled from the prepared photosensitive element. Measurement item: Ra (arithmetic mean roughness) Test conditions: Measurement length 259 μm (measured linearly) Objective lens: 50x magnification Number of measurements: n=2 Test environment: 23° C.±2° C., 50% RH±5% RH Testing machine: OLS4100 (manufactured by Olympus)

[0171] [Developed Area Ratio Sdr] The developed area ratio Sdr was measured for the uncoated surface (the surface opposite to the photosensitive resin composition layer) of the support film peeled from the prepared photosensitive element using a scanning white light interference microscope (VS1800 manufactured by Hitachi High-Tech) based on the method specified in ISO 25178. Measurement conditions: objective lens × 50, intermediate lens × 1, camera high-pixel measurement range: 112 μm × 112 μm, measurement mode: WAVE, surface correction: fourth-order surface correction

[0172] [Wafer Slipperiness] In accordance with JIS K7125-1987, a friction coefficient measuring instrument "TR-2" (Toyo Seiki Seisakusho) was used. An unprocessed bare wafer was fixed with a thread to a support film peeled from the prepared photosensitive element, and the tension (maximum load) was measured when a load of 200 g (normal force of 1.96 N) was applied and the wafer was moved 70 mm at 100 mm / min. The measurement was performed 10 times. A maximum load of less than 5 N in each measurement was judged as good, and a maximum load of 5 N or more was judged as bad. The results are shown in Tables 3 to 6.

[0173] <Photosensitive Element> [Thickness] The thickness of the support film and the photosensitive resin composition layer was measured using a dot-type thickness meter (FT-A series contact type continuous thickness meter manufactured by Fujiwork Co., Ltd. or dot-type VL-50 series manufactured by Mitutoyo Corporation).

[0174] [Circular hole resolution] (Evaluation substrate) A copper-clad laminate was laminated with ABF-GL102 (manufactured by Ajinomoto Fine-Tech Co., Inc.) as an insulating film, and the resulting evaluation substrate was subjected to desmear and electroless copper plating (forming a copper seed layer with a copper thickness of 1 μm). The surface roughness of the substrate was adjusted to Ra = 0.04 to 0.03 μm by adjusting the swelling temperature in the desmear process. The roughness was measured in the same manner as described above for the support film.

[0175] (Lamination) While peeling off the protective film of the photosensitive element, the photosensitive element was laminated onto an evaluation substrate preheated to 50°C using a hot roll laminator (AL-700, manufactured by Asahi Kasei Corporation) at a roll temperature of 105°C, thereby obtaining a photosensitive element laminate. The air pressure was 0.35 MPa, and the lamination speed was 1.5 m / min.

[0176] (Exposure) The surface side of the support film of the photosensitive element laminate, which had been left for 2 hours after lamination, was exposed to monochromatic i-line light (365 nm) using a segmented projection exposure system (UX-23101, manufactured by Ushio Inc.). A chrome glass photomask containing a circular hole design of 2 to 30 μmφ (in 1 μm increments) was used for exposure at an exposure amount that would yield the minimum resolution of each photosensitive element. For Examples 13 to 15 and Comparative Examples 7, 9, 10, 12, 14, and 15, a direct writing exposure system (FDi-3, manufactured by ORC Manufacturing Co., Ltd., light source peak wavelength: 405 nm) was used for exposure at an exposure amount that would yield the minimum resolution, using exposure data containing a circular hole design of 2 to 30 μmφ (in 1 μm increments).

[0177] (PEB: Post-Exposure Bake) The exposed photosensitive element laminate was heated for 1 minute in a hot air oven preheated to 60°C.

[0178] (Development) After peeling off the support film of the photosensitive element laminate, a 1% by mass Na2CO3 aqueous solution at 30°C was sprayed onto the photosensitive resin composition layer for a predetermined time using an alkali developing machine (a dry film developing machine manufactured by Fuji Kiko Co., Ltd.) to perform development. The developing spray time was twice the shortest developing time, and the water rinsing spray time after development was twice the shortest developing time. In this case, the shortest time required for the photosensitive resin composition layer in the unexposed areas to completely dissolve was defined as the shortest developing time.

[0179] (Confirmation of Optimum Exposure Amount) In a circular hole pattern obtained by exposure through a 15 μmφ mask, the exposure amount at which the diameter of the resolved circular holes measured was 15 μm±0.2 μm was set as the optimum exposure amount.

[0180] (Confirmation of Resolution) When 100 drawing patterns including a circular hole design of 2 to 30 μmφ were exposed at an optimum exposure dose, the smallest size of the circular holes in the drawing pattern among those that formed 98 or more holes was taken as the value of resolution.

[0181] [Yield Tests A to C] For the yield test designs (L / S = 2 μm / 4 μm, L / S = 4 μm / 6 μm, L / S = 8 μm / 13 μm) shown in FIG. 3, processes from lamination to development were carried out in the manner described above, and copper electroplating and flash etching were carried out in the following manner to form wiring.

[0182] FIG. 3 is a plan view showing an example of the configuration of a drawing pattern. In the drawing, in a drawing region 100A, an exposed region is designated by the reference symbol 10, and an unexposed region (hatched region) is designated by the reference symbol 1. The unexposed region 1 has a predetermined width and extends in the x direction, and a plurality of such unexposed regions 1 are arranged in the width direction (y direction) at predetermined intervals. By exposing a photosensitive resin layer based on the drawing pattern of FIG. 3, it is theoretically expected that a resist pattern having an L / S corresponding to the width of the unexposed region 1 (S: space) and the width of the exposed region 10 (L: line) will be formed.

[0183] (Electrolytic copper plating) The developed substrate was immersed in an electrolytic copper plating bath (copper sulfate 70 g / L, sulfuric acid 270 g / L, concentrated hydrochloric acid 50 ppm, and a small amount of additives) at a bath temperature of 25°C and a current density of 1.0 A / dm 2 Electrolytic plating was performed at 40°C for 10 minutes. This formed a plating pattern. A thickness gauge was used to confirm that the copper plating had a thickness of 5 to 6 μm, and the dry film was then peeled off from the substrate at 50°C using an organic amine stripper (Mitsubishi Gas Chemical Company, R-100S (15 vol%) + R-101 (8 vol%)).

[0184] (Flash Etching) The copper seed layer (1 μm thick) was removed by flash etching using a mixed etching solution of sulfuric acid and hydrogen peroxide (manufactured by Ebara Densan Co., Ltd.) to form a post-etching plating pattern (after plating and flash plating: L / S=3 / 3, L / S=5 / 5, L / S=9 / 12).

[0185] (Yield Test A) After plating and flash etching, a design containing 10 L / S = 3 / 3 patterns within a 0.2 mm x 0.2 mm area was spread over a 100 mm x 100 mm area, and a yield test was performed using AOI (automated optical inspection). The 0.2 mm x 0.2 mm area was defined as one field of view, and the 100 mm x 100 mm area was divided into 2,500 areas, with 100 fields of view defined as one area. For each area (2 mm x 2 mm) inspected by AOI, if there was even one field in which a pattern was missing or had a protruding shape that was 1 / 3 or more of the original data, it was counted as defective. The defect rate, which is the ratio of areas counted as defective to the total area, was calculated. The defect rate was ranked as follows: Excellent: Less than 10% Good: 10% to less than 20% Passable: 20% to less than 30% Poor: 30% or more (100% indicates that a pattern could not be formed, and less than 100% indicates that a pattern could be formed but the yield was poor.)

[0186] (Yield Test B) A yield test was performed using AOI on a design in which 10 L / S = 5 / 5 patterns were laid out in a 0.2 mm x 0.2 mm area after plating and flash etching, and the design was spread over a 100 mm x 100 mm area. The 0.2 mm x 0.2 mm area was defined as one field of view, and the 100 mm x 100 mm area was divided into 2,500 areas, with 100 fields of view defined as one area. For a single area (2 mm x 2 mm) inspected by AOI, if a pattern with a missing or protruding shape of 1 / 3 or more compared to the original data was present in even one field of view, it was counted as defective. The defect rate, which is the proportion of areas counted as defective out of the total area, was calculated. The defect rate was ranked as follows: Excellent: Less than 5%; Good: 5% to 10%; Poor: 10% or more (100% indicates that a pattern could not be formed, and less than 100% indicates that a pattern could be formed but the yield was poor).

[0187] (Yield Test C) A design containing 10 L / S=9 / 12 patterns within a 0.2 mm x 0.2 mm area after plating and flash etching was subjected to a yield test using AOI. The 0.2 mm x 0.2 mm area was defined as one field of view, and the 100 mm x 100 mm area was divided into 2,500 areas, with 100 fields of view defined as one area. For a single area (2 mm x 2 mm) inspected by AOI, if a pattern with a missing or protruding shape of 1 / 3 or more compared to the original data was present in even one field of view, it was counted as defective. The defect rate, which is the proportion of areas counted as defective, was calculated. The defect rate was evaluated using the following ranks: Excellent: Less than 1%; Good: 1% to less than 5%; Defective: 5% or greater (100% indicates that a pattern could not be formed, while less than 100% indicates that a pattern could be formed but the yield was poor).

[0188]

[0189]

[0190]

[0191]

[0192]

[0193]

[0194] Tables 3 and 4 show the results when the photosensitive resin composition layer was the same type but the support film was changed. As in Examples 1 to 9, when the number of foreign particles with a major diameter of 5 to 30 μm was small and the ratio of specific foreign particles was low, patterns could be formed with a good yield even at narrow pitches. Among these, Examples 4 to 8, in which the number of foreign particles with a major diameter of 10 to 20 μm and the ratio of specific foreign particles were small, had particularly good yields. On the other hand, when the number of foreign particles with a major diameter of 5 to 30 μm was large, as in Comparative Examples 1 to 5, the yield of narrow-pitch patterns was poor. For Examples 1 and 6, foreign particle evaluation was also performed using Inspection Method A in addition to Inspection Method B, and it was confirmed that the values ​​obtained using Inspection Method A and Inspection Method B were close to each other.

[0195] Referring to Tables 5 and 6, when there was little foreign matter, the photosensitive resin composition layer was thin, and the resolution was good, as in Examples 10 to 15, there was little pattern defect, and it was possible to form a pattern with a good yield even at a narrow pitch. On the other hand, when there was little foreign matter and the resolution was good but the photosensitive resin composition layer was thick, as in Comparative Examples 6 and 7, when there was little foreign matter and the photosensitive resin composition layer was thin but the resolution was poor, as in Comparative Examples 8 and 9, when there was little foreign matter but the photosensitive resin composition layer was thick and the resolution was poor, as in Comparative Example 10, when the resolution was good but there was a lot of foreign matter and the photosensitive resin composition layer was thick, as in Comparative Examples 11 and 12, when the photosensitive resin composition layer was thin but there was a lot of foreign matter and the resolution was poor, as in Comparative Examples 13 and 14, and when there was a lot of foreign matter and the photosensitive resin composition layer was thick and the resolution was poor, as in Comparative Example 15, although holes in the pattern did not occur, there were many defects, and it was not possible to form a narrow pitch.

[0196] The photosensitive element of the present invention can be suitably applied to the production of resist patterns or conductor patterns in printed wiring boards, flexible substrates, lead frame substrates, COF substrates, semiconductor package substrates, transparent electrodes for liquid crystal displays, TFT wiring for liquid crystal displays, PDP electrodes, etc.

Claims

A photosensitive element comprising a support film and a photosensitive resin composition layer, (1) The thickness of the photosensitive resin composition layer is 30 μm or less, (2) It is possible to resolve a circular hole pattern of 10 μmφ or less, (3) The number of foreign particles having a major axis of 5 μm to 30 μm present inside the support film is 0.0004 pieces / mm 2 is as follows: (4) A photosensitive element in which the ratio of the number of foreign particles having no voids observable with an optical microscope having an objective lens with a numerical aperture of 0.6 to the foreign particles having a major axis of 5 μm to 30 μm is 50% or less. 　 The number of foreign particles with a major axis of 10 μm to 20 μm present inside the support film is 0.00015 pieces / mm 2 is as follows:

2. The photosensitive element according to claim 1, wherein the ratio of the number of foreign particles having a major axis of 10 μm to 20 μm that do not have voids observable with an optical microscope having an objective lens with a numerical aperture of 0.6 is 50% or less. 　 The number of foreign particles with a major axis of 10 μm to 20 μm is 0.00001 pieces / mm 2 3. The photosensitive element of claim 2, wherein: 　 the support film includes a coating layer on the side opposite to the photosensitive resin composition layer side, the maximum load P when the sliding property between the surface of the support film on the coating layer side and a wafer is tested in accordance with JIS K7125 is 0.1 N≦P≦5.0 N; 2. The photosensitive element according to claim 1, wherein the developed area ratio Sdr, determined in accordance with ISO 25178, on the surface of the support film facing the coating layer satisfies 0.0001≦Sdr≦0.

005. When square pieces each having a side length of 5 mm are cut out from any 10 positions on the support film, the number average of the 10 positions on each small piece is the number of fine particles having a major axis of 1.5 μm or more and less than 4.5 μm is 0 to 200, the number of fine particles having a major axis of 4.5 μm or more and less than 10 μm is 0 to 10, 2. The photosensitive element according to claim 1, wherein the number of fine particles having a major axis of 10 μm or more is 0 to 1. 　 The photosensitive resin composition layer is (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, and (C) a polymerization initiator and / or a sensitizer, Including, The component (A) contains, based on the total amount of the component (A), 15% by mass to 65% by mass of structural units derived from (meth)acrylic acid and 30% by mass to 85% by mass of structural units derived from styrene and / or a styrene derivative, the component (B) contains a di(meth)acrylate having a bisphenol A skeleton in an amount of 15% by mass or more based on the total solid content of the photosensitive resin composition layer, 2. The photosensitive element according to claim 1, wherein the component (C) contains a compound having a biimidazole structure in an amount of 3% by mass or more based on the total solid content of the photosensitive resin composition layer. 　 The photosensitive resin composition layer is (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated bond, and (C) a polymerization initiator and / or a sensitizer, Including, The component (A) contains, based on the total amount of the component (A), 15% by mass to 65% by mass of structural units derived from (meth)acrylic acid and 30% by mass to 85% by mass of structural units derived from styrene and / or a styrene derivative, the component (B) contains a di(meth)acrylate having a bisphenol A skeleton in an amount of 15% by mass or more based on the total solid content of the photosensitive resin composition layer, the component (C) contains a compound having a biimidazole structure in an amount of 3 mass% or more based on the total solid content of the photosensitive resin composition layer, 2. The photosensitive element according to claim 1, wherein the component (C) further comprises a compound having at least one derivative skeleton selected from the group consisting of pyrazoline derivatives, anthracene derivatives, benzophenone derivatives, naphthalene derivatives, and oxazole derivatives.

2. The photosensitive element of claim 1, which is capable of resolving a pattern of circular holes of 5 μm diameter or less. 　 A photosensitive element comprising a support film and a photosensitive resin composition layer, (1) The thickness of the photosensitive resin composition layer is 30 μm or less, (2) It is possible to resolve a circular hole pattern of 10 μmφ or less, (3) The number of foreign particles with a major axis of 5 μm to 30 μm present in a range of 5% to 95% when the position on one side of the support film is defined as 0%, the position on the other side as 100%, and the position at the center in the thickness direction as 50% is 0.0004 pieces / mm 2 is as follows: (4) A photosensitive element in which the ratio of the number of foreign particles having no voids observable with an optical microscope having an objective lens with a numerical aperture of 0.6 to the foreign particles having a major axis of 5 μm to 30 μm is 50% or less. When the position on one side of the support film is defined as 0%, the position on the other side as 100%, and the position at the center in the thickness direction as 50%, the number of foreign particles with a major axis of 10 μm to 20 μm present in a range of 5% to 95% is 0.00015 pieces / mm 2 is as follows:

10. The photosensitive element according to claim 9, wherein the ratio of the number of foreign particles having no voids observable with an optical microscope having an objective lens with a numerical aperture of 0.6 to the foreign particles having a major axis of 10 μm to 20 μm is 50% or less. 　 The number of foreign particles with a major axis of 10 μm to 20 μm is 0.00001 pieces / mm 2 11. The photosensitive element of claim 10, wherein:

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