CN118778362A - Photosensitive resin composition and method for forming resist pattern - Google Patents

Abstract

The present invention provides a photosensitive resin composition for heating after exposure and then developing to obtain a cured resin. The present invention also relates to a method for forming a resist pattern. The above-mentioned photosensitive resin composition is based on its total solid content mass and comprises the following components: (A) 10% to 90% by mass of an alkali-soluble polymer, (B) 5% to 70% by mass of a compound having an ethylenically unsaturated double bond, and (C) 0.01% to 20% by mass of a photopolymerization initiator. The inorganic value (I value) of the alkali-soluble polymer (A) is 720 or less; or the solubility parameter (sp value) of the alkali-soluble polymer (A) is 21.45MPa ^1/2 or less; or the photosensitive resin composition comprises an alkali-soluble polymer (A-1) of 3% or more by mass based on the total solid content mass in the above-mentioned photosensitive resin composition, and the alkali-soluble polymer (A-1) comprises 52% or more of structural units derived from styrene and/or styrene derivatives as monomer components.

Description

Photosensitive resin composition and method for forming resist pattern

This application is a divisional application of an application filed on June 11, 2019, with application number 201980041589.0 and invention name “Photosensitive resin composition and method for forming an anti-etching pattern”.

Technical Field

The present invention relates to a photosensitive resin composition, a method for forming a resist pattern, and the like.

Background Art

Printed circuit boards and the like are used in electronic devices such as personal computers and mobile phones for mounting components, semiconductors, and the like. As resists for manufacturing printed circuit boards and the like, photosensitive resin laminates, so-called dry film photoresists (hereinafter sometimes referred to as "DF"), have been used in the past. The photosensitive resin laminates have a support layer, a photosensitive resin layer laminated on the support layer, and a protective layer laminated on the photosensitive resin layer as required. As the photosensitive resin layer, an alkali-developable resin layer using a weak alkali aqueous solution as a developer is generally used at present.

As a method for using DF to make a printed circuit board, for example, the following method can be cited. In the case where DF has a protective layer, the protective layer is first peeled off. Thereafter, DF is laminated on a substrate such as a copper-clad laminate or a flexible substrate for permanent circuit manufacturing, using a laminator or the like. The laminated DF is exposed through a wiring pattern mask film or the like. The supporting layer is peeled off as needed, and the photosensitive resin layer of the uncured portion (for example, the unexposed portion in the case of a negative type) is dissolved or dispersed and removed using a developer, thereby forming a cured resist pattern (hereinafter sometimes referred to as "resist pattern") on the substrate.

There are two methods for forming a circuit after forming a resist pattern. The first method is an etching method, which includes etching away the substrate surface (e.g., the copper surface of a copper-clad laminate) that is not covered by the resist pattern; and removing the resist pattern portion using an alkaline aqueous solution that is stronger than the developer. The second method is a plating method, which includes plating the substrate surface with copper, solder, nickel, tin, etc.; and removing the resist pattern portion in the same manner as the first method, and etching the exposed substrate surface (e.g., the copper surface of a copper-clad laminate). As a solution in etching, cupric chloride, ferric chloride, or a copper-ammine complex solution can be used.

In recent years, with the miniaturization and lightness of electronic devices, the miniaturization and high density of printed circuit boards have been developed. In the manufacturing process as described above, it is required to provide a high-performance DF with high resolution and high adhesion. For example, Patent Document 1 describes a photosensitive resin composition that improves resolution by using a specific thermoplastic resin, a monomer and a photopolymerization initiator. Patent Document 2 describes a method for forming a resist pattern, which includes a process of heating the exposed photosensitive resin composition layer and the substrate together under pressure using a pressing and heating mechanism. Patent Document 3 describes a method for forming a resist pattern, which includes exposing, heating and developing a laminate having (a) a photosensitive layer and (b) a resin layer formed on a substrate. Patent Document 4 describes a method for forming a resist pattern, which has a process of placing the laminate under a reduced pressure atmosphere or a low oxygen concentration atmosphere at least during the period from exposure to heating treatment. Patent Document 5 describes various additives that are optionally included in the photosensitive resin layer of DF. Patent Document 6 describes a protective layer preferably applied to DF.

Prior art literature

Patent Literature

Patent Document 1: Japanese Patent Application Publication No. 2010-249884

Patent Document 2: Japanese Patent Application Publication No. 2014-191318

Patent Document 3: Japanese Patent Application Publication No. 2016-224161

Patent Document 4: Japanese Patent Application Publication No. 2016-224162

Patent Document 5: Japanese Patent Application Publication No. 2013-156369

Patent Document 6: Japanese Patent Application Laid-Open No. 59-202457

Summary of the invention

Problem that the invention aims to solve

After the exposure process, depending on the situation, the photosensitive resin layer is sometimes subjected to a heating process (post-exposure heating: PEB), and then developed. By implementing this heating process, it is possible to achieve further improvement in high resolution and high adhesion. However, even if the post-exposure heating process is performed, the improvement in adhesion of the conventional photosensitive resin composition is not sufficient. In addition, if a long time has passed after exposure, even if the post-exposure heating process is performed, sometimes good adhesion cannot be obtained.

The present invention is made in view of such existing actual conditions, and one of the objects of the present invention is to provide a photosensitive resin composition that can significantly improve the adhesion when developing after heating after exposure. In particular, in a preferred embodiment, one of the objects is to provide a photosensitive resin composition that exhibits good adhesion even when a long time has passed from exposure to heating.

Solutions for solving problems

The inventors of the present application have repeatedly conducted intensive research to solve the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved by a photosensitive resin composition containing an alkali-soluble polymer having an inorganic value (I value) within a specific range; an alkali-soluble polymer having a solubility parameter (sp value) within a specific range; or an alkali-soluble polymer (A-1) having a structural unit of a specific structure, thereby completing the present invention. The following embodiments [1] to [29] list examples of embodiments of the present invention.

[1] A photosensitive resin composition for obtaining a cured resin by heating after exposure and then developing, wherein the photosensitive resin composition comprises the following components based on the total solid content of the photosensitive resin composition:

(A) 10 to 90% by mass of an alkali-soluble polymer,

(B) 5 to 70% by mass of a compound having an ethylenically unsaturated double bond, and

(C) 0.01% to 20% by mass of a photopolymerization initiator,

The inorganic value (I value) of the alkali-soluble polymer (A) is 720 or less.

[2] The photosensitive resin composition according to item 1, wherein the I value of the alkali-soluble polymer (A) is 635 or less.

[3] The photosensitive resin composition according to item 2, wherein the I value of the alkali-soluble polymer (A) is 600 or less.

[4] The photosensitive resin composition according to any one of items 1 to 3, wherein the alkali-soluble polymer (A) has an I value of 300 or more.

[5] The photosensitive resin composition according to item 4, wherein the I value of the alkali-soluble polymer (A) is 400 or more.

[6] The photosensitive resin composition according to item 5, wherein the I value of the alkali-soluble polymer (A) is 450 or more.

[7] The photosensitive resin composition according to item 6, wherein the I value of the alkali-soluble polymer (A) is 500 or more.

[8] The photosensitive resin composition according to item 7, wherein the I value of the alkali-soluble polymer (A) is 550 or more.

[9] A photosensitive resin composition that is used to obtain a cured resin by heating after exposure and then developing, wherein the photosensitive resin composition comprises the following components based on the total solid content of the photosensitive resin composition:

(A) 10 to 90% by mass of an alkali-soluble polymer,

(B) 5 to 70% by mass of a compound having an ethylenically unsaturated double bond, and

(C) 0.01% to 20% by mass of a photopolymerization initiator,

The solubility parameter (sp value) of the above-mentioned (A) alkali-soluble polymer is 21.45 MPa ^1/2 or less.

[10] The photosensitive resin composition according to item 9, wherein the solubility parameter (sp value) of the alkali-soluble polymer (A) is 21.40 MPa ^1/2 or less.

[11] The photosensitive resin composition according to item 10, wherein the solubility parameter (sp value) of the alkali-soluble polymer (A) is 21.20 MPa ^1/2 or less.

[12] The photosensitive resin composition according to any one of items 9 to 11, wherein the solubility parameter (sp value) of the alkali-soluble polymer (A) is 19.00 MPa ^1/2 or more.

[13] The photosensitive resin composition according to item 12, wherein the solubility parameter (sp value) of the alkali-soluble polymer (A) is 19.50 MPa ^1/2 or more.

[14] The photosensitive resin composition according to item 13, wherein the solubility parameter (sp value) of the alkali-soluble polymer (A) is 20.00 MPa ^1/2 or more.

[15] The photosensitive resin composition according to item 14, wherein the solubility parameter (sp value) of the alkali-soluble polymer (A) is 20.50 MPa ^1/2 or more.

[16] A photosensitive resin composition which is used to obtain a cured resin by heating after exposure and then developing, wherein the photosensitive resin composition comprises the following components based on the total solid content of the photosensitive resin composition:

(A) 10 to 90% by mass of an alkali-soluble polymer,

(B) 5 to 70% by mass of a compound having an ethylenically unsaturated double bond, and

(C) 0.01% to 20% by mass of a photopolymerization initiator,

The photosensitive resin composition comprises, as the alkali-soluble polymer (A), 3% by mass or more of an alkali-soluble polymer (A-1) based on the total solid content in the photosensitive resin composition, wherein the alkali-soluble polymer (A-1) comprises 52% by mass or more of structural units derived from styrene and/or styrene derivatives as monomer components.

[17] The photosensitive resin composition according to item 16, wherein the photosensitive resin composition contains 10% by mass or more of the alkali-soluble polymer (A-1) based on the total solid content in the photosensitive resin composition.

[18] The photosensitive resin composition according to item 16 or 17, wherein the alkali-soluble polymer (A-1) contains 55% by mass or more of a structural unit derived from styrene and/or a styrene derivative as a monomer component.

[19] The photosensitive resin composition according to item 18, wherein the alkali-soluble polymer (A-1) contains 58% by mass or more of a structural unit derived from styrene and/or a styrene derivative as a monomer component.

[20] The photosensitive resin composition according to any one of items 16 to 19, wherein the alkali-soluble polymer (A-1) contains 27% by mass or more of a structural unit derived from (meth)acrylic acid as a monomer component.

[21] The photosensitive resin composition according to any one of items 16 to 19, wherein the alkali-soluble polymer (A-1) further includes a structural unit derived from benzyl (meth)acrylate as a monomer component.

[22] A method for forming a resist pattern, comprising the following steps:

A step of exposing the layer of the photosensitive resin composition according to any one of items 1 to 21;

a heating step of heating the exposed photosensitive resin composition layer; and

A developing step of developing the heated photosensitive resin composition layer.

[23] The method for forming a resist pattern according to item 22, wherein the heating temperature in the heating step is in the range of 30°C to 150°C.

[24] The method for forming a resist pattern according to item 22 or 23, wherein the heating step is performed within 15 minutes after the exposure is stopped.

[25] The method for forming a resist pattern according to any one of items 22 to 24, wherein the exposure step is performed by an exposure method based on direct drawing of a drawing pattern or an exposure method in which an image of a photomask is projected through a lens.

[26] The method for forming a resist pattern according to item 25, wherein the exposure step is performed by an exposure method based on direct drawing of a drawing pattern.

[27] The method for forming a resist pattern according to item 26, wherein the exposure step is performed by exposing using a first laser having a central wavelength less than 390 nm and a second laser having a central wavelength greater than 390 nm.

[28] The method for forming a resist pattern according to Item 27, wherein the central wavelength of the first laser is greater than or equal to 350 nm and less than or equal to 380 nm, and the central wavelength of the second laser is greater than or equal to 400 nm and less than or equal to 410 nm.

[29] A method for manufacturing a circuit substrate, comprising: manufacturing a resist pattern on a substrate by the method described in any one of items 22 to 28, and etching or plating the substrate having the resist pattern to form the circuit substrate.

Effects of the Invention

According to the present invention, the adhesion of the resist pattern when developing after post-exposure heating (PEB) can be significantly improved. In a preferred embodiment, a photosensitive resin composition that exhibits good adhesion even when a long time has passed from exposure to heating can be provided. It should be noted that the above description cannot be regarded as disclosing all embodiments of the present invention and all advantages related to the present invention. Further embodiments of the present invention and their advantages are clarified by referring to the following description.

DETAILED DESCRIPTION

Hereinafter, the embodiment of the present invention will be described in detail for the purpose of illustrating the embodiment of the present invention, but the present invention is not limited to the embodiment of the present invention. In the present specification, the upper limit and the lower limit of each numerical range can be arbitrarily combined.

[Photosensitive resin composition]

The photosensitive resin composition of the present embodiment is a photosensitive resin composition for obtaining a cured resin by heating after exposure and then developing. The photosensitive resin composition comprises the following components based on the total solid content mass of the photosensitive resin composition: (A) 10% to 90% by mass of an alkali-soluble polymer, (B) 5% to 70% by mass of a compound having an ethylenically unsaturated double bond, and (C) 0.01% to 20% by mass of a photopolymerization initiator.

〈(A) Alkali-soluble polymer〉

In this embodiment, the inorganic value (I value) of the alkali-soluble polymer (A) in the photosensitive resin composition can be 720 or less. Here, "I value" is also referred to as "inorganic value", which indicates the degree of physical properties mainly caused by electrical affinity. "O value" is also referred to as "organic value", which indicates the degree of physical properties mainly caused by van der Waals forces. The I/O value is a parameter that represents the scale of the lipophilicity/hydrophilicity of a compound or substituent, and is determined based on the I value and O value inherent in the compound or substituent. A large I/O value indicates high inorganicity. For details on the I/O value, refer to "Organic Concept Diagram" by Yoshio Koda, Sankyo Publishing, 1984, etc.

In this embodiment, the solubility parameter (sp value) of the alkali-soluble polymer (A) in the photosensitive resin composition may be 21.45 MPa ^1/2 or less. The solubility parameter (sp value) refers to the square root of the aggregate energy density of a substance. For details and calculation methods, refer to Toshinao Okitsu, "The Role of Solubility Parameter (SP) in Solubility Theory (First Report)", Journal of the Japanese Adhesion Society, 1993, vol. 29, No. 5, pp. 8-15, etc. In this application specification, the SP value refers to the value calculated using the Okitsu method.

In this embodiment, the photosensitive resin composition may include, as an alkali-soluble polymer (A), 3% by mass or more of an alkali-soluble polymer (A-1) relative to the total solid content in the photosensitive resin composition, wherein the alkali-soluble polymer (A-1) contains 52% by mass or more of structural units derived from styrene and/or styrene derivatives as monomer components.

The photosensitive resin composition of the present embodiment can significantly improve the adhesion during development after exposure, heating, and development by having any one or more of the inorganic value (I value), the solubility parameter (sp value), and the alkali-soluble polymer (A-1). The photosensitive resin composition of the present embodiment may be, for example, an alkali-soluble polymer (A) having an inorganic value (I value) of 720 or less and a solubility parameter (sp value) of 21.45 MPa ^1/2 or less; or an alkali-soluble polymer (A) having an inorganic value (I value) of 720 or less and containing 3% by mass or more of the alkali-soluble polymer (A-1) relative to the total solid content mass; or an alkali-soluble polymer (A) having a solubility parameter (sp value) of 21.45 MPa ^1/2 or less and containing 3% by mass or more of the alkali-soluble polymer (A-1) relative to the total solid content mass; or, an alkali-soluble polymer (A) having an inorganic value (I value) of 720 or less, a solubility parameter (sp value) of 21.45 MPa ^1/2 or less and containing 3% by mass or more of the alkali-soluble polymer (A-1) relative to the total solid content mass.

Generally speaking, the dry film resist obtained from the photosensitive resin composition has a tendency to be difficult to improve in adhesion unless it is heated immediately after exposure. In contrast, the dry film resist obtained from the photosensitive resin composition of the present embodiment can exhibit good adhesion even after a long period of time from exposure to heating, and can obtain a fine resist pattern.

As a reason for the improvement of adhesion when developing after heating after exposure, although not limited by theory, the inventors speculate as follows. If the inorganic value (I value) of the alkali-soluble polymer is 720 or less, the electrical affinity of the alkali-soluble polymer is low, the permeability during development is suppressed, and the swelling/dissolution resistance becomes higher. As a result, it can be considered that even a fine anti-etching pattern will not suffer losses due to development and can be maintained. In addition, if the time from exposure to heating becomes longer, the free radicals generated during exposure collide with the oxygen in the alkali-soluble polymer and become inactivated, so the effect of PEB is reduced. However, it can be considered that alkali-soluble polymers with low electrical affinity are difficult to contain water molecules because water is difficult to ionize, and the movement of oxygen is hindered. Therefore, even if the time elapsed is longer, the effect of PEB can be maintained. It is believed that if the solubility parameter (sp value) of the alkali-soluble polymer is less than 21.45 MPa ^1/2 , the hydrophobicity of the alkali-soluble polymer is high, and the swelling/dissolution resistance during development becomes high. As a result, even a fine resist pattern will not suffer loss due to development and can be maintained. In addition, it is believed that the hygroscopicity of the alkali-soluble polymer with high hydrophobicity is low, and the oxygen migration of water molecules is hindered. Therefore, even if the time from exposure to heating becomes longer, the effect of PEB can be maintained. The photosensitive resin composition contains an alkali-soluble polymer (A-1) of 3% by mass or more relative to the total solid content mass in the photosensitive resin composition, thereby greatly improving the fluidity of the resin by heating after exposure, and can highly take into account the hydrophobicity of the styrene skeleton and the reactivity of the carbon-carbon double bond. As a result, the adhesion can be significantly improved. In addition, by significantly improving the adhesion, good adhesion can be obtained even after a long time after exposure.

The upper limit of the inorganic value (I value) of the alkali-soluble polymer is preferably less than 635 or less than 600, and the lower limit is preferably more than 300, more than 350, more than 400, more than 450, more than 500 or more than 550. By making the inorganic value (I value) more than 350, there is an advantage that the residue of the alkali-soluble polymer is not easy to remain between the fine wirings. One alkali-soluble polymer can be used alone, or two or more can be mixed. When two or more are mixed, the inorganic value (I value) as the alkali-soluble polymer mixture is preferably within a specific range in the present embodiment. The inorganic value (I value) of the mixture, when assuming additive properties, can be obtained in the form of the sum of the values obtained by multiplying the I value of each component by the weight fraction.

The upper limit of the solubility parameter (sp value) of the alkali-soluble polymer is preferably below 21.40MPa ^1/2 or below 21.20MPa ^1/2 , and the lower limit is preferably above 19.00MPa ^1/2 , above 19.50MPa ^1/2 , above 20.00MPa ^1/2 or above ^{20.50MPa 1/2} . By making the solubility parameter (sp value) above 19.00MPa ^1/2 , there is an advantage that the residue of the alkali-soluble polymer is not easy to remain between fine wirings. Alkali-soluble polymers can be used alone, or two or more can be mixed. When two or more are mixed, the solubility parameter (sp value) as the alkali-soluble polymer mixture is preferably within the specific range in the present embodiment. As the solubility parameter (sp value) of the mixture, when it is assumed to have additivity, it can be obtained in the form of the sum of the values obtained by multiplying the sp values of each component by the weight fraction.

In the present embodiment, the alkali-soluble polymer refers to a polymer that is easily soluble in alkaline substances to the extent that the resulting photosensitive resin layer has developability and stripping properties for alkaline aqueous solutions. More specifically, the amount of carboxyl groups contained in the alkali-soluble polymer is preferably 100g to 600g or 250g to 450g in terms of acid equivalent. The acid equivalent refers to the mass (unit: gram) of a polymer having 1 equivalent of carboxyl groups in the molecule. The carboxyl groups in the alkali-soluble polymer impart developability and stripping properties to the photosensitive resin layer for alkaline aqueous solutions. If the acid equivalent is 100 or more, the development tolerance, resolution and adhesion are improved. The acid equivalent is more preferably 250g or more. If the acid equivalent is 600g or less, the developability and stripping properties are improved. The acid equivalent is more preferably 450g or less. In the present application specification, the acid equivalent is a value measured by a potentiometric titration method using a potentiometric titration apparatus and titrating with a 0.1 mol/L NaOH aqueous solution.

The weight average molecular weight (Mw) of the alkali-soluble polymer is preferably 5,000 to 500,000. If the weight average molecular weight is 500,000 or less, the resolution and developability are improved. The weight average molecular weight is more preferably 100,000 or less, 70,000 or less, 60,000 or less, or 50,000 or less. If the weight average molecular weight is 5,000 or more, it is easier to control the properties of the developed aggregates, and the properties of the unexposed film such as the edge fuse and cut chip properties in the photosensitive resin laminate. The weight average molecular weight is more preferably 10,000 or more or 20,000 or more. Edge fuse refers to the degree of ease with which the photosensitive resin layer is exposed from the end face of the roll when the photosensitive resin laminate is rolled into a roll. Cut chipping refers to the degree of ease with which chips are splashed when the unexposed film is cut with a cutter. If the chip debris adheres to the upper surface of the photosensitive resin laminate, etc., it will be transferred to the mask in the subsequent exposure step, etc., and will cause defective products.

The dispersion degree of the alkali-soluble polymer, which is defined as the ratio (Mw/Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn), is preferably 1.0 to 6.0, more preferably 1.0 to 5.0, further preferably 1.0 to 4.0, and further preferably 1.0 to 3.0. The weight average molecular weight (Mw) and number average molecular weight (Mn) of the alkali-soluble polymer are both polystyrene-converted values measured by gel permeation chromatography (GPC).

In order to provide a higher adhesion when developing after heating after exposure, especially a better adhesion after a long time after exposure, the alkali-soluble polymer preferably contains a structural unit derived from a monomer component having an aromatic hydrocarbon group. As an aromatic hydrocarbon group, for example, substituted or unsubstituted phenyl and substituted or unsubstituted aralkyl can be listed. The lower limit of the amount of the monomer component having an aromatic hydrocarbon group in the alkali-soluble polymer is based on the total mass of all monomer components of the alkali-soluble polymer, preferably 20% by mass or more, 40% by mass or more, 50% by mass or more, 55% by mass or more or 60% by mass or more. The upper limit of the amount of the monomer component having an aromatic hydrocarbon group is not limited, and can be, for example, 95% by mass or less or 80% by mass or less. When the photosensitive resin composition contains a variety of alkali-soluble polymers, the amount of the monomer component having an aromatic hydrocarbon group is obtained as a weight average.

As the monomer having an aromatic hydrocarbon group, for example, monomers having an aralkyl group, styrene, and styrene derivatives can be cited. When the alkali-soluble polymer contains a structural unit derived from a monomer having an aralkyl group, styrene, or a styrene derivative, a higher resolution can be provided. As such an alkali-soluble polymer, for example, a copolymer containing methacrylic acid, benzyl methacrylate, and styrene, a copolymer containing methacrylic acid, methyl methacrylate, benzyl methacrylate, and styrene, etc. are preferred.

As the aralkyl group, substituted or unsubstituted phenylalkyl (excluding benzyl) and substituted or unsubstituted benzyl can be listed, and substituted or unsubstituted benzyl is preferred. As the comonomer having a phenylalkyl group, phenylethyl (meth)acrylate can be listed. As the comonomer having a benzyl group, (meth)acrylates having a benzyl group, such as benzyl (meth)acrylate and benzyl (meth)acrylate chloride, and vinyl monomers having a benzyl group, such as vinylbenzyl chloride and vinylbenzyl alcohol, can be listed. As the comonomer having a benzyl group, benzyl (meth)acrylate is preferred.

The alkali-soluble polymer is preferably a polymer of a first monomer having a polymerizable unsaturated group and a carboxyl group in the molecule, and more preferably a copolymer of the first monomer and a non-acidic second monomer having a polymerizable unsaturated group in the molecule. When the alkali-soluble polymer contains a monomer component having an aromatic hydrocarbon group, the alkali-soluble polymer is preferably a copolymer of a monomer having an aromatic hydrocarbon group and at least one first monomer and/or at least one second monomer.

The first monomer is a monomer having a polymerizable unsaturated group and a carboxyl group in the 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. The first monomer is preferably (meth)acrylic acid. In the present application specification, "(meth)acrylic acid" refers to acrylic acid or methacrylic acid, "(meth)acryloyl" refers to acryloyl or methacryloyl, and "(meth)acrylate" refers to "acrylate" or "methacrylate".

The amount of the first monomer in the alkali-soluble polymer is based on the total mass of all monomer components constituting the alkali-soluble polymer, preferably 10% to 50% by mass. If the amount of the first monomer is more than 10% by mass, it is possible to provide better developability and easier control of edge fusion. The amount of the first monomer is more preferably more than 15% by mass or more than 20% by mass. If the amount of the first monomer is less than 50% by mass, it is possible to provide a higher resolution of the resist pattern, a better hem shape and higher chemical resistance. The amount of the first monomer is more preferably less than 35% by mass, less than 32% by mass or less than 30% by mass.

The second monomer is a non-acidic monomer having at least one polymerizable unsaturated group in the molecule. As the second monomer, for example, (meth)acrylate methyl, (meth)acrylate ethyl, (meth)acrylate n-propyl, (meth)acrylate isopropyl, (meth)acrylate n-butyl, (meth)acrylate isobutyl, (meth)acrylate tert-butyl, (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate cyclohexyl, (meth)acrylate 2-ethylhexyl (meth)acrylate and other (meth)acrylate compounds; ester compounds of vinyl alcohol such as vinyl acetate; and (meth)acrylonitrile. As the second monomer, it is preferably at least one selected from the group consisting of methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate and n-butyl (meth)acrylate.

The amount of the second monomer in the alkali-soluble polymer is based on the total mass of all monomer components constituting the alkali-soluble polymer, preferably 10% to 50% by mass. If the amount of the second monomer is more than 10% by mass, it is possible to provide better developability and easier control of edge fusion. The amount of the second monomer is more preferably more than 15% by mass or more than 20% by mass. If the amount of the second monomer is less than 50% by mass, it is possible to provide a higher resolution of the resist pattern, a better hem shape and higher chemical resistance. The amount of the second monomer is more preferably less than 35% by mass, less than 32% by mass or less than 30% by mass.

The alkali-soluble polymer may comprise only one alkali-soluble polymer, or may be a mixture of two or more alkali-soluble polymers. In the case of a mixture of two or more alkali-soluble polymers, the alkali-soluble polymer preferably comprises two or more alkali-soluble polymers comprising monomer components with aromatic hydrocarbon groups, or comprises one or more alkali-soluble polymers comprising monomer components with aromatic hydrocarbon groups and comprises one or more alkali-soluble polymers comprising monomer components with aromatic hydrocarbon groups. In the case of the latter, the amount of the alkali-soluble polymer comprising the monomer components with aromatic hydrocarbon groups is preferably 50% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more or 95% by mass or more relative to the gross mass of the alkali-soluble polymer.

The alkali-soluble polymer is more preferably an alkali-soluble polymer (A-1) containing a structural unit of styrene and/or a styrene derivative as a monomer component. Examples of styrene derivatives include methyl styrene, vinyl toluene, tert-butoxy styrene, acetoxy styrene, 4-vinyl benzoic acid, styrene dimer, and styrene trimer.

The amount of the alkali-soluble polymer (A-1) contained in the photosensitive resin composition is preferably 3% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, based on the total solid content in the photosensitive resin composition.

The structural unit of the alkali-soluble polymer (A-1), i.e. the total amount of styrene and/or styrene derivatives, is preferably 52% by mass or more, 55% by mass or more, 58% by mass or more or 60% by mass or more, based on the gross mass of the alkali-soluble polymer (A-1). By comprising more than 52% by mass of structural units derived from styrene and/or styrene derivatives, and developing after heating after exposure, even a system with a large content of styrene skeleton can greatly improve the fluidity of the resin due to heating, and the hydrophobicity of the styrene skeleton and the reactivity of the carbon-carbon double bond can be highly taken into account. As a result, adhesion can be significantly improved. Moreover, by significantly improving adhesion, good adhesion can be obtained even when the time after exposure becomes long.

If the content of the styrene skeleton is small, the fluidity of the resin (the resulting cured resin) will not be excessively reduced, and the desired reactivity and adhesion will be more easily obtained. In addition, if a long time has passed after exposure, the free radicals in the system gradually become inactivated, and therefore, over time, the effect of improving adhesion by heating after exposure gradually decreases. From these viewpoints, the total amount of the structural units of the alkali-soluble polymer (A-1), i.e., styrene and/or styrene derivatives, is preferably 90% by mass or less, 80% by mass or less, 75% by mass or less, or 70% by mass or less, based on the total mass of the alkali-soluble polymer (A-1).

In order to provide a higher adhesion when developing after heating after exposure, especially a better adhesion after a long time after exposure, the alkali-soluble polymer (A-1) preferably further contains a structural unit derived from (meth) acrylic acid as a monomer component. The amount of the structural unit derived from (meth) acrylic acid is based on the total mass of the alkali-soluble polymer (A-1), preferably 25% by mass or more, 26% by mass or more, 27% by mass or more, 28% by mass or more, or 29% by mass or more. From the same point of view, the amount of the structural unit derived from (meth) acrylic acid is based on the total mass of the alkali-soluble polymer (A-1), preferably 35% by mass or less, 32% by mass or less, or 30% by mass or less.

In order to provide a higher adhesion when developing after heating after exposure, especially a better adhesion after exposure for a long time, the alkali-soluble polymer (A-1) preferably further comprises a structural unit derived from benzyl (meth)acrylate as a monomer component. The amount of the structural unit derived from benzyl (meth)acrylate is based on the total mass of the alkali-soluble polymer (A-1), preferably 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more. From the same point of view, the amount of the structural unit derived from benzyl (meth)acrylate is based on the total mass of the alkali-soluble polymer (A-1), preferably 35% by mass or less, 32% by mass or less, or 30% by mass or less.

The weight average value Tg ^total of the glass transition temperature Tg of the alkali-soluble polymer (A) is preferably 30°C or more and 150°C or less. By making the Tg ^total of the alkali-soluble polymer below 150°C, it is possible to provide higher adhesion when developing after heating after exposure, especially better adhesion when exposed for a long time. The Tg ^total of the alkali-soluble polymer is more preferably below 135°C, below 130°C, below 125°C, below 120°C or below 110°C. By making the Tg ^total of the alkali-soluble polymer above 30°C, it is possible to provide higher edge fusion resistance. The Tg ^total of the alkali-soluble polymer is more preferably above 40°C, above 50°C or above 60°C.

The amount of the alkali-soluble polymer (A) contained in the photosensitive resin composition is preferably 10% to 90% by mass, 30% to 70% by mass, or 40% to 60% by mass, based on the total solid content of the photosensitive resin composition. If the amount of the alkali-soluble polymer in the photosensitive resin composition is 90% by mass or less, it is easier to control the development time. If the amount of the alkali-soluble polymer in the photosensitive resin composition is 10% by mass or more, it is possible to provide higher edge fusion resistance.

The synthesis of alkali-soluble polymer (A) can be carried out by diluting a single or multiple monomers constituting the alkali-soluble polymer with a solvent, adding a free radical polymerization initiator in an appropriate amount, and heating and stirring to polymerize it. As the solution used for polymerization, solvents such as acetone, methyl ethyl ketone and isopropanol can be listed. As free radical polymerization initiators, benzoyl peroxide and azoisobutyronitrile can be listed. A part of the mixture of monomers can be added dropwise to the reaction solution while synthesizing, instead of diluting all monomers with a solution at one time. After the reaction is completed, a solvent can be further added to adjust to the desired concentration. As a synthesis method, in addition to solution polymerization, bulk polymerization, suspension polymerization and emulsion polymerization can be listed.

<(B) Compounds having ethylenically unsaturated double bonds>

In order to provide a better curability of the resin composition and a higher compatibility with an alkali-soluble polymer, the compound (B) having an ethylenically unsaturated double bond preferably contains a compound having a (meth)acryloyl group in the molecule. The number of (meth)acryloyl groups relative to one molecule of compound (B) may be one or more. From the viewpoint of providing better peelability and softness of the cured film, examples of compounds having one (meth)acryloyl group include compounds having (meth)acrylic acid added to a single end of a polyalkylene oxide; compounds having (meth)acrylic acid added to a single end of a polyalkylene oxide and the other end alkylated or allyl etherified; and phthalic acid compounds, etc.

Examples of the compound having one (meth)acryloyl group include a (meth)acrylate of a compound obtained by adding polyethylene glycol to a phenyl group, namely, phenoxyhexaethylene glycol mono(meth)acrylate; a (meth)acrylate of a compound obtained by adding polypropylene glycol to which an average of 2 mol of propylene oxide is added and polyethylene glycol to which an average of 7 mol of ethylene oxide is added to nonylphenol, namely, 4-n-nonylphenoxyheptaethylene glycol dipropylene glycol (meth)acrylate; a (meth)acrylate of a compound obtained by adding polypropylene glycol to which an average of 2 mol of propylene oxide is added and polyethylene glycol to which an average of 7 mol of ethylene oxide is added to nonylphenol, namely, 4-n-nonylphenoxyheptaethylene glycol dipropylene glycol (meth)acrylate; (Meth)acrylates of compounds obtained by adding polypropylene glycol having an average of 1 mol of propylene oxide and polyethylene glycol having an average of 5 mol of ethylene oxide to nonylphenol, i.e., 4-n-nonylphenoxypentaethylene glycol monopropylene glycol (meth)acrylate; and acrylates of compounds obtained by adding polyethylene glycol having an average of 8 mol of ethylene oxide to nonylphenol, i.e., 4-n-nonylphenoxyoctaethylene glycol (meth)acrylate (e.g., M-114 manufactured by Toagosei Co., Ltd.). From the viewpoint of providing higher sensitivity, resolution, and adhesion, compounds having one (meth)acryloyl group may also include γ-chloro-β-hydroxypropyl-β'-methacryloyloxyethyl phthalate.

Examples of the compound having two (meth)acryloyl groups include compounds having (meth)acryloyl groups at both ends of an alkylene oxide chain and compounds having (meth)acryloyl groups at both ends of an alkylene oxide chain in which an ethylene oxide chain and a propylene oxide chain are randomly or block-bonded.

Examples of compounds having two (meth)acryloyl groups include polyethylene glycol (meth)acrylates such as tetraethylene glycol di(meth)acrylate, pentaethylene glycol di(meth)acrylate, hexaethylene glycol di(meth)acrylate, heptaethylene glycol di(meth)acrylate, octaethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, decaethylene glycol di(meth)acrylate, and compounds having (meth)acryloyl groups at both ends of 12 mols of ethylene oxide chains; and polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, and polyalkylene oxide di(meth)acrylate compounds containing ethylene oxide groups and propylene oxide groups in the molecule. As a polyoxyalkylene di(meth)acrylate compound containing an ethylene oxide group and a propylene oxide group in the molecule, for example, dimethacrylate of a glycol obtained by further adding an average of 3 mols of ethylene oxide to both ends of a polypropylene glycol to which an average of 12 mols of propylene oxide are added, and dimethacrylate of a glycol obtained by further adding an average of 15 mols of ethylene oxide to both ends of a polypropylene glycol to which an average of 18 mols of propylene oxide are added, etc. More specifically, FA-023M, FA-024M, FA-027M (product name, manufactured by Hitachi Chemical Co., Ltd.) and the like can be cited. They are preferred because they can provide higher flexibility, resolution, and adhesion.

An example of a compound having two (meth)acryloyl groups in a molecule includes a compound having (meth)acryloyl groups at both ends by modifying bisphenol A with an alkylene oxide from the viewpoint of providing higher resolution and adhesion. Specifically, a compound represented by the following general formula (I) is preferred.

{In the formula, _R1 and _R2 each independently represent a hydrogen atom or a methyl group, A is _C2H4 , _B is _C3H6 , _n1 and _n3 each independently represent _an integer of 1 to 39, and _n1 + _n3 represents an integer of 2 to 40, _n2 and _n4 each independently represent an integer of 0 to 29, and _n2 + _n4 represents an integer of 0 to 30, and the arrangement of the repeating units of -(AO)- and -(BO)- may be random or block. In the case of a block, any of -(AO)- and -(BO)- may be on the biphenyl side.}

From the viewpoint of providing higher resolution and adhesion, preferably, polyethylene glycol dimethacrylate having an average of 5 mol of ethylene oxide added to both ends of bisphenol A, polyethylene glycol dimethacrylate having an average of 2 mol of ethylene oxide added to both ends of bisphenol A, or polyethylene glycol dimethacrylate having an average of 1 mol of ethylene oxide added to both ends of bisphenol A. The aromatic ring in the general formula (I) above may have a hetero atom and/or a substituent.

Examples of heteroatoms include halogen atoms. Examples of substituents include alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 10 carbon atoms, aryl groups having 6 to 18 carbon atoms, phenacyl groups, amino groups, alkylamino groups having 1 to 10 carbon atoms, dialkylamino groups having 2 to 20 carbon atoms, nitro groups, cyano groups, carbonyl groups, mercapto groups, alkylmercapto groups having 1 to 10 carbon atoms, aryl groups, hydroxyl groups, hydroxyalkyl groups having 1 to 20 carbon atoms, carboxyl groups, carboxylalkyl groups having 1 to 10 carbon atoms in alkyl groups, acyl groups having 1 to 10 carbon atoms in alkyl groups, alkoxy groups having 1 to 20 carbon atoms, alkoxycarbonyl groups having 1 to 20 carbon atoms, alkylcarbonyl groups having 2 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, N-alkylcarbamoyl groups having 2 to 10 carbon atoms, or groups containing heterocyclic rings, and aryl groups substituted with these substituents. These substituents may form a condensed ring. The hydrogen atoms in these substituents may be substituted with heteroatoms such as halogen atoms. When the aromatic ring in the general formula (I) has a plurality of substituents, the plurality of substituents may be the same or different.

Examples of the compound having three or more (meth)acryloyl groups in the molecule include compounds obtained by (meth)acrylating an alcohol obtained by adding an alkyleneoxy group such as ethyleneoxy, propyleneoxy, or butyleneoxy to a group having three or more mols of an alkylene oxide group as a central skeleton to which an alkylene oxide group can be added in the molecule. In this case, examples of the compound capable of forming the central skeleton include glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, and isocyanurate ring. Examples of compounds having three or more (meth)acryloyl groups include tri(meth)acrylates, such as ethoxylated glycerol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc.; tetra(meth)acrylates, such as di(trimethylolpropane) tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, etc.; penta(meth)acrylates, such as dipentaerythritol penta(meth)acrylate, etc.; and hexa(meth)acrylates, such as dipentaerythritol hexa(meth)acrylate, etc. From the viewpoints of resolution, adhesion, and resist hem shape, compounds having three or more (meth)acryloyl groups are preferred, and compounds having three or more methacryloyl groups are more preferred.

As the trimethylolpropane tri(meth)acrylate, from the viewpoint of high flexibility and adhesion and suppression of bleeding, for example, trimethacrylate in which an average of 21 mol of ethylene oxide is added to trimethylolpropane and trimethacrylate in which an average of 30 mol of ethylene oxide is added to trimethylolpropane are preferred.

As the tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate is preferred. Pentaerythritol tetra(meth)acrylate may be, for example, a tetra(meth)acrylate obtained by adding 1 to 40 mol of alkylene oxide to the four ends of pentaerythritol. As the hexa(meth)acrylate, for example, a hexa(meth)acrylate obtained by adding 1 to 40 mol of ethylene oxide to the six ends of dipentaerythritol, or a hexa(meth)acrylate obtained by adding 1 to 20 mol of ε-caprolactone to the six ends of dipentaerythritol is preferred.

The (meth)acrylate compounds can be used independently or in combination. In the photosensitive resin composition, other compounds may be included as the compound (B) having an ethylenically unsaturated bond. Other compounds include (meth)acrylates having an urethane bond, compounds obtained by reacting a polyol with an α,β-unsaturated carboxylic acid, compounds obtained by reacting a compound containing a glycidyl group with an α,β-unsaturated carboxylic acid, and 1,6-hexanediol di(meth)acrylate.

The amount of the compound (B) having an ethylenically unsaturated double bond contained in the photosensitive resin composition is preferably 5% to 70% by mass, based on the total solid content mass in the photosensitive resin composition. If the amount of the compound (B) is 5% by mass or more, it is preferred from the viewpoints of sensitivity, resolution and adhesion. The amount of the compound (B) is more preferably 20% by mass or more or 30% by mass or more. If the amount of the compound (B) is 70% by mass or less, it is preferred from the viewpoint of suppressing edge fusion and delayed peeling of the cured resist. The amount of the compound (B) is more preferably 50% by mass or less.

In the present embodiment, the compound (B) may be a compound (B1) having an ethylenically unsaturated double bond and having a structure represented by the following general formula (II).

{In formula (II), A is a divalent hydrocarbon group having 4 or more carbon atoms}. When compound (B) contains compound (B1), it may contain only compound (B1), or, in addition to compound (B1), it may further contain a compound (B2) having an ethylenically unsaturated double bond and not having the structure represented by the above general formula (II).

[Compound (B1)]

The number of ethylenically unsaturated double bonds contained in the compound (B1) may be 1 or more, and from the viewpoint of improving the residual film property during development and the physical properties of the cured product, it is preferably 2 or more, more preferably 2 or more and 6 or less, further preferably 2 or more and 4 or less, and further preferably 2. From the viewpoint of compatibility with the alkali-soluble polymer and the curability of the photosensitive resin composition, the ethylenically unsaturated double bonds contained in the compound (B1) are preferably groups selected from acryloyl and methacryloyl groups (hereinafter also referred to as "(meth)acryloyl groups").

Examples of the compound (B1) include compounds represented by the following general formula (III).

{wherein, the (AO) portion corresponds to the above (II), A is a divalent hydrocarbon group having 4 or more carbon atoms, preferably a divalent hydrocarbon group having 4 to 8 carbon atoms, ^B1 and ^B2 are each independently an ethylene group or a propylene group, the arrangement of ( ^B1 -O), (AO) and ( ^B2 -O) may be random or block, n1 is an integer of 0 to 50, n2 is an integer of 2 to 100, n3 is an integer of 0 to 50, and ^R1 and ^R2 are each independently a hydrogen atom or a methyl group}.

A in formula (III) is a divalent hydrocarbon group having 4 or more carbon atoms, preferably a divalent hydrocarbon group having 4 to 8 carbon atoms. The divalent hydrocarbon group may be linear or branched, and may also contain an alicyclic ring. A is preferably a linear or branched alkylene group. Specific examples of A include tetramethylene, pentamethylene, hexamethylene, octamethylene, butane-2,3-diyl, butane-1,2-diyl, pentane-2,3-diyl, pentane-1,4-diyl, 2,2-dimethyl-1,3-propylene, hexane-1,5-diyl, and the like. A is preferably a divalent hydrocarbon group having 4 carbon atoms, more preferably an alkylene group having 4 carbon atoms, and particularly preferably a tetramethylene group. n2 is an integer of 2 to 100, preferably an integer of 3 to 75, and more preferably an integer of 4 to 50.

^B1 and ^B2 in formula (III) can be independently selected from 1,2-ethylene, 1,2-propylene, 1,3-propylene, etc. n1 and n3 are independently an integer of 0 to 50, preferably an integer of 0 to 30, an integer of 0 to 20, or an integer of 0 to 10. n1+n3 is preferably an integer of 0 to 10. The arrangement of ( ^B1 -O), (AO) and ( ^B2 -O) can be random or block. ^R1 and ^R2 are independently a hydrogen atom or a methyl group.

As compound (B1), it is preferred to select compounds wherein both n1 and n3 in formula (III) are 0, and compounds wherein both n1 and n3 in formula (III) are 1 to 50 (preferably 1 to 30, 1 to 20 or 1 to 10). As compounds wherein both n1 and n2 in formula (III) are 0, for example, di(meth)acrylates of poly(1,4-butylene glycol) to which 2 to 100 mol of butylene oxide are added can be cited. As compounds wherein both n1 and n2 in formula (III) are 1 to 50, for example, di(meth)acrylates of poly(alkylene glycol) obtained by further adding 1 to 50 mol of ethylene oxide or propylene oxide to both ends of poly(1,4-butylene glycol) to which 2 to 100 mol of butylene oxide are added can be cited.

Compound (B1) may include only one compound, or may be a mixture of two or more compounds in which one or more of 1, ^B1 , ^B2 , ^R1 , ^R2 , n1, n2, and n3 in formula (III) are different.

Compound (B2) is a compound having an ethylenically unsaturated double bond and not having a structure represented by formula (II). The number of ethylenically unsaturated double bonds contained in compound (B2) can be 1 or more, and from the viewpoint of improving the residual film property during development and the physical properties of the cured product, it is preferably 2 or more, more preferably 2 or more and 10 or less, 2 or more and 8 or less, or 2 or more and 6 or less. From the viewpoint of compatibility with alkali-soluble polymers and curability of the photosensitive resin composition, the ethylenically unsaturated double bond contained in compound (B2) is preferably a (meth)acryloyl group.

Examples of the compound (B2) having two (meth)acryloyl groups include a compound having (meth)acryloyl groups at both ends of an alkylene oxide chain and a compound having (meth)acryloyl groups added to both ends of an alkylene oxide chain of bisphenol A modified with alkylene oxide.

Among the compounds (B2), the alkylene oxide chain in the compound having (meth)acryloyl groups at both ends of the alkylene oxide chain is a group in which two or more alkylene oxides selected from ethylene oxide and propylene oxide are linked. When the compound (B2) contains both ethylene oxide and propylene oxide, they may be linked randomly or in blocks, or a random linking site and a block linking site may be mixed.

Examples of such a compound (B2) include tetraethylene glycol di(meth)acrylate, pentaethylene glycol di(meth)acrylate, hexaethylene glycol di(meth)acrylate, heptaethylene glycol di(meth)acrylate, octaethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, decaethylene glycol di(meth)acrylate, a compound having a (meth)acryloyl group at both ends of 12 mols of ethylene oxide chains, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, a dimethacrylate of a diol obtained by further adding an average of 3 mols of ethylene oxide to both ends of a polypropylene glycol to which an average of 12 mols of propylene oxide is added, and a dimethacrylate of a diol obtained by further adding an average of 15 mols of ethylene oxide to both ends of a polypropylene glycol to which an average of 18 mols of propylene oxide is added. More specifically, FA-023M, FA-024M, and FA-027M (manufactured by Hitachi Chemical Co., Ltd.) are mentioned, etc. These are preferred from the viewpoints of flexibility, resolution, adhesion, and the like.

Among the compounds (B2), a compound in which a (meth)acryloyl group is added to both ends of an alkylene oxide chain of bisphenol A modified with an alkylene oxide may specifically be a compound represented by the following general formula (I), for example.

{In formula (I), _R1 and _R2 each independently represent _a hydrogen atom or a methyl group, A is _C2H4 , B is _C3H6 , n1 and n3 each independently represent an integer of 1 to 39, and n1+n3 is an integer of 2 to 40, n2 and n4 each independently represent an integer of 0 to 29, _and n2+n4 is an integer of 0 to 30, the arrangement of the repeating units of -(AO)- and -(BO)- may be random or block, and in the case of a block, any of the -(AO)-block and the -(BO)-block may be on the biphenyl side.}

As such a compound (B2), from the viewpoints of resolution and adhesion, etc., preferred are, for example, polyethylene glycol dimethacrylate obtained by adding an average of 5 mol of ethylene oxide to each of the two ends of bisphenol A; polyethylene glycol dimethacrylate obtained by adding an average of 2 mol of ethylene oxide to each of the two ends of bisphenol A; and polyethylene glycol dimethacrylate obtained by adding an average of 1 mol of ethylene oxide to each of the two ends of bisphenol A.

Among the compounds (B2), compounds having three or more (meth)acryloyl groups include, for example, compounds obtained by adding an ethyleneoxy group or a propyleneoxy group to an alcohol having three or more moles of a group capable of adding an alkylene oxide group to the molecule as a central skeleton to form a (meth)acrylate. In this case, compounds capable of forming a central skeleton include, for example, glycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, isocyanurate ring, etc. These tri(meth)acrylates, tetra(meth)acrylates, penta(meth)acrylates, hexa(meth)acrylates, etc. can be used as compounds (B2) having three or more (meth)acryloyl groups.

Among the compounds (B2), examples of tri(meth)acrylates include ethoxylated glycerol tri(meth)acrylate, ethoxylated isocyanuric acid tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, etc. Among the trimethylolpropane tri(meth)acrylates, from the viewpoints of flexibility, adhesion, and suppression of bleed-out, for example, trimethacrylate obtained by adding an average of 21 mol of ethylene oxide to trimethylolpropane, trimethacrylate obtained by adding an average of 30 mol of ethylene oxide to trimethylolpropane, etc. are preferred.

Among the compounds (B2), examples of tetra(meth)acrylates include di(trimethylolpropane)tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, and dipentaerythritol tetra(meth)acrylate. Among these, pentaerythritol tetra(meth)acrylate is preferred. Pentaerythritol tetra(meth)acrylate is preferably a tetra(meth)acrylate obtained by adding a total of 1 mol or more and 40 mol or less of an alkylene oxide to the four ends of pentaerythritol.

Among the compounds (B2), examples of penta(meth)acrylates include dipentaerythritol penta(meth)acrylate and the like.

Among the compounds (B2), preferred hexa(meth)acrylates include, for example, hexa(meth)acrylates obtained by adding 1 mol or more and 40 mol or less of ethylene oxide to the six terminals of dipentaerythritol, and hexa(meth)acrylates obtained by adding 1 mol or more and 20 mol or less of ε-caprolactone to the six terminals of dipentaerythritol.

The compound (B2) may contain only one compound or may be a mixture of two or more compounds.

When compound (B) contains compound (B1) and compound (B2), the amount of compound (B1) is preferably 5% by mass or more, 7% by mass or more, 8% by mass or more, 9% by mass or more, or 10% by mass or more, based on the total mass of compound (B). The amount of compound (B1) is preferably 50% by mass or less, 30% by mass or less, or 20% by mass or less, based on the total mass of compound (B).

Particularly preferred embodiments in which compound (B) includes compound (B1) are listed in the following [Scheme 1] to [Scheme 18].

[Solution 1]

A photosensitive resin composition is used for sequentially performing exposure, heating and development to obtain a resist pattern.

The photosensitive resin composition comprises the following components based on the total solid content of the photosensitive resin composition:

(A) 10% by mass or more and 90% by mass or less of an alkali-soluble polymer;

(B) 5% by mass or more and 70% by mass or less of a compound having an ethylenically unsaturated double bond; and

(C) 0.01% by mass to 20% by mass of a photopolymerization initiator, and

The compound (B) having an ethylenically unsaturated double bond includes a compound (B1) having a structure represented by the following general formula (II).

{In formula (II), A is a divalent hydrocarbon group having 4 or more carbon atoms.}

[Solution 2]

The photosensitive resin composition according to Embodiment 1, wherein the compound (B1) is a compound having two or more ethylenically unsaturated double bonds.

[Solution 3]

The photosensitive resin composition according to embodiment 1 or 2, wherein the compound (B1) is a compound represented by the following general formula (III).

{In formula (III), A is a divalent hydrocarbon group having 4 to 8 carbon atoms, ^B1 and ^B2 are each independently an ethylene group or a propylene group, the arrangement of ( ^B1 -O), (AO) and ( ^B2 -O) may be random or block, n1 is an integer of 0 to 50, n2 is an integer of 2 to 100, n3 is an integer of 0 to 50, and ^R1 and ^R2 are each independently a hydrogen atom or a methyl group.}

[Solution 4]

The photosensitive resin composition according to Embodiment 3, wherein n1 and n3 in the general formula (III) are each independently an integer of 0 to 30.

[Solution 5]

The photosensitive resin composition according to embodiment 3 or 4, wherein in the general formula (III), n1+n3 is an integer of 0 to 10.

[Solution 6]

The photosensitive resin composition according to any one of aspects 1 to 5, wherein A in the general formula (III) is a divalent hydrocarbon group having 4 carbon atoms.

[Solution 7]

The photosensitive resin composition according to any one of aspects 1 to 6, wherein the compound (B) having an ethylenically unsaturated double bond further includes a compound (B2) having an ethylenically unsaturated double bond and not having the structure represented by the general formula (II).

[Scheme 8]

The photosensitive resin composition according to any one of aspects 1 to 7, further comprising a photosensitizer.

[Solution 9]

The photosensitive resin composition according to Embodiment 8, wherein the photosensitizer contains an anthracene compound.

[Scheme 10]

The photosensitive resin composition according to aspect 8 or 9, wherein the photosensitizer contains a dihydropyrazole compound.

[Scheme 11]

The photosensitive resin composition according to any one of aspects 1 to 10, wherein the photopolymerization initiator (C) contains an imidazole compound.

[Scheme 12]

A photosensitive resin laminate comprising:

a support layer; and

A layer of the photosensitive resin composition according to any one of aspects 1 to 11 on the support layer.

[Scheme 13]

A method for forming a resist pattern, comprising the following steps:

A step of exposing the layer of the photosensitive resin composition according to any one of embodiments 1 to 11;

a heating step of heating the photosensitive resin composition layer after the exposure step; and

A developing step of developing the photosensitive resin composition layer after the heating step.

[Scheme 14]

The method for forming a resist pattern according to claim 13, wherein the heating temperature in the heating step is in the range of 30° C. to 150° C.

[Scheme 15]

The method for forming a resist pattern according to claim 13 or 14, wherein the exposure step is performed by an exposure method based on direct drawing of a drawing pattern or an exposure method based on projecting an image of a photomask through a lens.

[Scheme 16]

The method for forming a resist pattern according to claim 13 or 14, wherein the exposure step is performed by an exposure method based on direct drawing of a drawing pattern.

[Scheme 17]

The method for forming a resist pattern according to claim 16, wherein the exposure step is performed by exposing using a first laser having a central wavelength of less than 390 nm and a second laser having a central wavelength of 390 nm or more.

[Scheme 18]

The method for forming a resist pattern according to claim 17, wherein the central wavelength of the first laser light is greater than or equal to 350 nm and less than or equal to 380 nm, and the central wavelength of the second laser light is greater than or equal to 400 nm and less than or equal to 410 nm.

<(C) Photopolymerization initiator>

The photopolymerization initiator (C) is a compound that polymerizes a monomer using light, and may be a photopolymerization initiator generally known in the technical field.

The amount of the photopolymerization initiator in the photosensitive resin composition is preferably 0.01 to 20 mass %, 0.05 to 10 mass %, 0.1 to 7 mass %, or 0.1 to 6 mass %, based on the total solid content of the photosensitive resin composition. If the total amount of the photopolymerization initiator is 0.01 mass % or more, sufficient sensitivity can be obtained, and if it is 20 mass % or less, light is fully transmitted to the bottom surface of the resist, and good high resolution can be obtained.

Examples of photopolymerization initiators include quinone compounds, aromatic ketone compounds, acetophenone compounds, acylphosphine oxide compounds, benzoin or benzoin ether compounds, dialkyl ketal compounds, thioxanthone compounds, dialkylaminobenzoate compounds, oxime ester compounds, acridine compounds, hexaarylbiimidazoles, dihydropyrazole compounds, anthracene compounds, coumarin compounds, N-aryl amino acids or their ester compounds, and halides.

As the aromatic ketone compound, for example, benzophenone, Michler's ketone [4,4'-bis (dimethylamino) benzophenone], 4,4'-bis (diethylamino) benzophenone, 4-methoxy-4'-dimethylamino benzophenone can be cited. Among these, from the viewpoint of adhesion, 4,4'-bis (diethylamino) benzophenone is preferred. From the viewpoint of transmittance, the content of the aromatic ketone compound in the photosensitive resin composition is preferably 0.01% by mass to 0.5% by mass or 0.02% by mass to 0.3% by mass based on the total solid content mass of the photosensitive resin composition.

As the acridine compound, from the viewpoint of sensitivity, resolution and adhesion, 9-phenylacridine, bisacridinylheptane, 9-(p-methylphenyl)acridine and 9-(m-methylphenyl)acridine are preferred. As the anthracene compound, an anthracene derivative having an alkoxy group having 1 to 40 carbon atoms and/or an aryl group having 6 to 40 carbon atoms and optionally having a substituent at the 9th and/or 10th positions is preferred, and from the viewpoint of sensitivity, resolution and adhesion, 9,10-diphenylanthracene, 9,10-dibutoxyanthracene and 9,10-diethoxyanthracene are preferred. As the coumarin compound, from the viewpoint of sensitivity, resolution and adhesion, 7-diethylamino-4-methylcoumarin is preferred. As the N-aryl amino acid or its ester compound, from the viewpoint of sensitivity, resolution and adhesion, N-phenylglycine is preferred, for example. As the halide, tribromomethylphenylsulfone is preferred, for example. Examples of the photopolymerization initiator include 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropane-1-one, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, and triphenylphosphine oxide.

Examples of the hexaarylbiimidazole include 2-(o-chlorophenyl)-4,5-diphenylbiimidazole, 2,2',5-tris(o-chlorophenyl)-4-(3,4-dimethoxyphenyl)-4',5'-diphenylbiimidazole, 2,4-bis(o-chlorophenyl)-5-(3,4-dimethoxyphenyl)-diphenylbiimidazole, 2,4,5-tris(o-chlorophenyl)-diphenylbiimidazole, 2-(o-chlorophenyl)-bis-4,5-(3,4-dimethoxyphenyl)-biimidazole, 2,2'-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-methoxyphenyl)-biimidazole )-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(2,4,5-trifluorophenyl)-4,4',5,5'-tetrakis(3-methoxyphenyl)-biimidazole, , 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 and 2,2'-bis(2,3,4,5,6-pentafluorophenyl)-4,4',5,5'-tetrakis(3-methoxyphenyl)-biimidazole. From the viewpoint of high sensitivity, resolution and adhesion, the hexaarylbiimidazole is preferably 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer. From the viewpoint of improving the release property and/or sensitivity of the photosensitive resin layer, the amount of the hexaarylbiimidazole compound in the photosensitive resin composition is preferably in the range of 0.05 to 7 mass %, 0.1 to 6 mass %, or 1 to 5 mass %.

The photopolymerization initiator can be used alone or in combination of two or more.

〈Photosensitizer〉

From the viewpoint of high transmittance, improving the stripping characteristics and/or sensitivity of the photosensitive resin layer, the photosensitive resin composition may further contain a photosensitizer. As photosensitizers, dihydropyrazole compounds and anthracene compounds can be listed. The content of the photosensitizer in the photosensitive resin composition is based on the total solid content mass of the photosensitive resin composition, preferably 0.01% by mass to 10% by mass, 0.05% by mass to 5% by mass, 0.1% by mass to 3% by mass, 0.1% by mass to 1% by mass or 0.1% by mass to 0.7% by mass. If the amount of the photosensitizer is 0.01% by mass or more, the stripping characteristics and sensitivity of the photosensitive resin layer can be further improved. If the amount of the photosensitizer is 10% by mass or less, the light transmittance of the photosensitive resin layer can be maintained at a high level, which is preferred from the viewpoint of exposure efficiency.

Examples of the dihydropyrazole compound include 1-phenyl-3-(4-tert-butyl-phenyl)-5-(4-tert-butyl-phenyl)-dihydropyrazole, 1-(4-(benzoxazol-2-yl)phenyl)-3-(4-tert-butyl-phenyl)-5-(4-tert-butyl-phenyl)-dihydropyrazole, 1-phenyl-3-(4-biphenylyl)-5-(4-tert-butyl-phenyl)-dihydropyrazole, 1-phenyl-3-(4-biphenylyl)-5-(4-tert-octyl-phenyl)-dihydropyrazole, 1-phenyl-3-(4-isopropylphenyl)-5-(4-isopropylphenyl)-dihydropyrazole, 1-phenyl-3-(4-methoxyphenyl)-5-(4-methoxyphenyl)-dihydropyrazole, and 1-phenyl-3-(4-methoxyphenyl)-5-(4-methoxyphenyl)-dihydropyrazole. 3-(3,5-dimethoxyphenylvinyl)-5-(3,5-dimethoxyphenyl)-dihydropyrazole, 1-phenyl-3-(3,4-dimethoxyphenylvinyl)-5-(3,4-dimethoxyphenyl)-dihydropyrazole, 1-phenyl-3-(2,6-dimethoxyphenylvinyl)-5-(2,6-dimethoxyphenyl)-dihydropyrazole, 1-phenyl-3-(2,5-dimethoxyphenylvinyl)-5-(2,5-dimethoxyphenyl)-dihydropyrazole, 1-phenyl-3-(2,3-dimethoxyphenylvinyl)-5-(2,3-dimethoxyphenyl)-dihydropyrazole, and 1-phenyl-3-(2,4-dimethoxyphenylvinyl)-5-(2,4-dimethoxyphenyl)-dihydropyrazole, etc. As the dihydropyrazole compound, 1-phenyl-3-(4-biphenylyl)-5-(4-tert-butyl-phenyl)-dihydropyrazole is more preferred.

As the anthracene compound, from the viewpoint of sensitivity, resolution, and adhesion, for example, a dialkoxyanthracene compound such as 9,10-diphenylanthracene, 9,10-dibutoxyanthracene, and 9,10-diethoxyanthracene is preferred.

〈Phenol derivatives〉

From the viewpoint of resolution and adhesion, the photosensitive resin composition preferably further contains a phenol derivative. Examples of the phenol derivative include p-methoxyphenol, hydroquinone, pyrogallol, tert-butylcatechol, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2,6-di-tert-butyl-4-methylphenol, 2,5-di-tert-amylhydroquinone, 2,5-di-tert-butylhydroquinone, 2, 2'-Methylenebis(4-methyl-6-tert-butylphenol), bis(2-hydroxy-3-tert-butyl-5-ethylphenyl)methane, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], pentaerythritol-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] Ester], 2,2-dithiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid octadecyl ester, N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamic acid amide), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tri( 3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, 4,4'-thiobis(6-tert-butyl-m-cresol), 4,4'-butylenebis(3-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, styrenated phenol (e.g., ANTAGE SP manufactured by Kawaguchi Chemical Industries, Ltd.), tribenzylphenol (e.g., TBP manufactured by Kawaguchi Chemical Industries, Ltd., phenol having 1 to 3 benzyl groups), biphenol, and the like.

The amount of the phenol derivative in the photosensitive resin composition is preferably 0.001% to 10% by mass based on the total solid content of the photosensitive resin composition. From the viewpoint of resolution and adhesion, the lower limit of the amount of the phenol derivative is more preferably 0.005% by mass or more, 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more. From the viewpoint of less reduction in sensitivity and improved resolution, the lower limit of the amount of the phenol derivative is more preferably 5% by mass or less, 2% by mass or less, 1% by mass or less, 0.5% by mass or less, or 0.3% by mass or less.

<additive>

The photosensitive resin composition may contain additives such as a colorant, a stabilizer, an adhesive aid, and a plasticizer as desired. For example, additives listed in Japanese Unexamined Patent Publication No. 2013-156369 may be used.

(Colorant)

In this embodiment, the photosensitive resin composition may further contain at least one selected from the group consisting of a coloring agent, for example, a dye and a coloring matter, as desired.

As coloring materials, for example, magenta, phthalocyanine green, basic yellow, para-magenta, crystal violet, methyl orange, Nile blue 2B, Victoria blue, malachite green (for example, Hodogaya Chemical Co., Ltd., Aizen (registered trademark) MALACHITEGREEN), basic blue 20 and diamond green (for example, Hodogaya Chemical Co., Ltd., Aizen (registered trademark) DIAMOND GREENGH). The amount of the coloring material in the photosensitive resin composition is preferably 0.001% by mass to 1% by mass based on the total solid content of the photosensitive resin composition. If the amount of the coloring material is 0.001% by mass or more, the handling property of the photosensitive resin composition is improved. If the amount of the coloring material is 1% by mass or less, it is easy to maintain the storage stability of the photosensitive resin composition.

The photosensitive resin composition makes the exposed part color by containing a dye, so it is preferred from the viewpoint of visual observability. When the inspection machine reads the alignment mark for exposure, it is advantageous to easily identify the exposed part when the contrast between the exposed part and the unexposed part is large. From these viewpoints, preferred dyes include leuco dyes and fluoran dyes. As leuco dyes, tris (4-dimethylaminophenyl) methane [leuco crystal violet], bis (4-dimethylaminophenyl) phenyl methane [leuco malachite green], etc. can be listed. From the viewpoint of good contrast, leuco crystal violet is more preferred as a leuco dye. The amount of the dye in the photosensitive resin composition is preferably 0.1% to 10% by mass based on the total solid content mass of the photosensitive resin composition. If the amount of the dye is 0.1% by mass or more, the contrast between the exposed part and the unexposed part becomes better. The amount of the dye is more preferably 0.2% by mass or more or 0.4% by mass or more. If the amount of the dye is 10% by mass or less, it is easy to maintain the storage stability of the photosensitive resin composition. The amount of the dye is more preferably 5% by mass or less or 2% by mass or less.

From the viewpoint of optimizing adhesion and contrast, the photosensitive resin composition preferably contains a combination of a leuco dye and a halide described in the column "(C) Photopolymerization Initiator". When a leuco dye and a halide are used in combination, if the amount of the halide in the photosensitive resin composition is 0.01% by mass to 3% by mass based on the total solid content of the photosensitive resin composition, it is easy to maintain the storage stability of the hue in the photosensitive layer.

(Stabilizer)

The photosensitive resin composition may further contain a stabilizer in order to improve thermal stability and storage stability. The stabilizer may be, for example, at least one compound selected from the group consisting of a radical inhibitor, a benzotriazole compound, and a carboxybenzotriazole compound.

Examples of the radical polymerization inhibitor include naphthylamine, cuprous chloride, nitrosophenylhydroxylamine aluminum salt, diphenylnitrosoamine, etc. In order not to impair the sensitivity of the photosensitive resin composition, nitrosophenylhydroxylamine aluminum salt is preferred.

Examples of the benzotriazole compound 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.

Examples of the carboxybenzotriazole compound 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.

The total amount of the stabilizer in the photosensitive resin composition is preferably 0.01% to 3% by mass or 0.05% to 1% by mass, based on the total solid content of the photosensitive resin composition. If the total amount of the stabilizer is 0.01% by mass or more, the photosensitive resin composition can be given high storage stability. If the total amount of the stabilizer is 3% by mass or less, it is preferred from the viewpoint of maintaining sensitivity and inhibiting dye fading. The fading of the dye can be measured at a transmittance of 630 nm. A high transmittance at a wavelength of 630 nm indicates that the dye has been fading. The transmittance of the laminate of the support layer and the photosensitive resin composition layer at a wavelength of 630 nm is preferably 80% or less, 78% or less, 75% or less, 72% or less, 70% or less, 68% or less, 65% or less, 62% or less, 60% or less, 58% or less, 55% or less, 52% or less or 50% or less. This transmittance is the transmittance of the laminated body of the support layer and the photosensitive resin composition layer, and does not include the protective layer.

(Adhesive additive)

The photosensitive resin composition may further contain an epoxy compound of bisphenol A. Examples of the epoxy compound of bisphenol A include compounds obtained by modifying bisphenol A with polypropylene glycol and epoxidizing the terminal thereof.

(Plasticizer)

The photosensitive resin composition may further contain a plasticizer. Examples of the plasticizer include phthalate compounds (e.g., diethyl phthalate), o-toluenesulfonamide, p-toluenesulfonamide, tributyl citrate, triethyl citrate, acetyl triethyl citrate, acetyl tri-n-propyl citrate, acetyl tri-n-butyl citrate, polyethylene glycol, polypropylene glycol, polyethylene glycol alkyl ether, and polypropylene glycol alkyl ether. More specifically, compounds having a bisphenol skeleton such as ADEKANOLSDX-1569, ADEKANOL SDX-1570, ADEKANOL SDX-1571 and ADEKANOL SDX-479 (manufactured by Asahi Denka Corporation); NEWPOL BP-23P, NEWPOL BP-3P, NEWPOL BP-5P, NEWPOL BPE-20T, NEWPOL BPE-60, NEWPOL BPE-100 and NEWPOL BPE-180 (manufactured by Sanyo Chemical Co., Ltd.); UNIOL DB-400, UNIOL DAB-800, UNIOL DA-350F, UNIOL DA-400 and UNIOL DA-700 (manufactured by NOF Corporation); and BA-P4U GLYCOL and BA-P8 GLYCOL (manufactured by Nippon Emulsifier Co., Ltd.) can also be cited.

The amount of the plasticizer in the photosensitive resin composition is preferably 1% to 50% by mass or 1% to 30% by mass based on the total solid content of the photosensitive resin composition. If the amount of the plasticizer is 1% by mass or more, it is preferred from the viewpoint of suppressing the delay of the development time and imparting flexibility to the cured film. If the amount of the plasticizer is 50% by mass or less, it is preferred from the viewpoint of suppressing insufficient curing and cold flow.

〈Solvent〉

The photosensitive resin composition can be dissolved in a solvent and used in the form of a photosensitive resin composition preparation liquid to manufacture a photosensitive resin laminate. Examples of the solvent include ketone compounds and alcohol compounds. Examples of ketone compounds include methyl ethyl ketone (MEK) and acetone. Examples of alcohol compounds include methanol, ethanol and isopropanol. The amount of solvent added to the photosensitive resin composition is preferably an amount in which the viscosity of the photosensitive resin composition preparation liquid coated on the support layer at 25°C reaches 500mPa·s to 4,000mPa·s.

If the amount of water in the photosensitive resin composition is high, the local plasticization of the photosensitive resin composition is sometimes rapidly promoted, and edge fusion occurs. Therefore, from the viewpoint of inhibiting edge fusion, it is preferred that the amount of water in the photosensitive resin composition is less. The amount of water in the photosensitive resin composition is such that the mass of the photosensitive resin composition after the prepared solution of the photosensitive resin composition is applied to the support layer and dried is measured as a reference (moisture content after drying) to reach 0.7% by mass or less. The amount of water after drying in the photosensitive resin composition is more preferably 0.65% by mass or less, 0.6% by mass or less, 0.55% by mass or less, 0.5% by mass or less, 0.45% by mass or less, 0.4% by mass or less, 0.35% by mass or less, 0.3% by mass or less, 0.25% by mass or less, or 0.2% by mass or less.

[Photosensitive resin laminate]

In this embodiment, the photosensitive resin laminate of the present invention has a support layer and has a layer of the photosensitive resin composition of this embodiment on the support layer (hereinafter also referred to as "photosensitive resin layer"). A protective layer may be further provided on the photosensitive resin layer.

〈Supporting layer〉

As the support layer, a transparent support film that transmits light emitted from the exposure light source is preferred. Examples of the support film include polyethylene terephthalate films, polyvinyl alcohol films, polyvinyl chloride films, vinyl chloride copolymer films, polyvinylidene chloride films, vinylidene chloride copolymer films, polymethyl methacrylate copolymer films, polystyrene films, polyacrylonitrile films, styrene copolymer films, polyamide films, and cellulose derivative films. As the support layer, a stretched support film may be used as required.

From the viewpoint of suppressing light scattering during exposure, the haze of the support layer is preferably less than 5%, less than 2%, less than 1.5% or less than 1.0%. From the same viewpoint, the surface roughness Ra of the surface of the support layer in contact with the photosensitive layer is preferably less than 30nm, less than 20nm or less than 10nm. The thinner the thickness of the support layer, the more it will improve image formation and economy, so it is advantageous, however, in order to maintain the strength of the photosensitive resin laminate, it is preferably 10μm to 30μm. The support layer may contain particles such as a lubricant as desired. The size of the particles is preferably less than 5μm.

The support layer may be a single-layer structure or a multi-layer structure in which a plurality of resin layers are stacked. In the case of a multi-layer structure, an antistatic layer may be provided. As an example of a multi-layer structure, a support layer having a two-layer structure and a resin layer on one side of a substrate and a support layer having a three-layer structure and a resin layer on both sides of a substrate may be provided. As a scheme for a three-layer support layer, the following scheme may be provided: the support film exemplified above is used as a substrate, one side A of the support film has a resin layer containing microparticles, and on the other side B,

(1) having a resin layer containing substantially the same amount of particles as the resin layer on the side of surface A;

(2) having a resin layer containing a smaller amount of particles than the resin layer on the side of surface A;

(3) having a resin layer containing finer particles than those contained in the resin layer on the side of surface A; and

(4) Having a resin layer that does not contain particles; etc.

In the case of the structures of (2), (3) and (4) above, it is preferred to have a photosensitive resin layer on the side of surface B. In this case, it is preferred to have a resin layer containing microparticles on the side of surface A opposite to the photosensitive resin layer from the viewpoint of the slipperiness of the film, etc. The size of the microparticles contained in the resin layer is preferably less than 1.5 μm.

<Photosensitive resin layer>

The photosensitive resin laminate has a photosensitive resin layer on a supporting layer. The photosensitive resin layer is a layer formed from the photosensitive resin composition of the present embodiment. The thickness of the photosensitive resin layer in the photosensitive resin laminate varies depending on the application, and is preferably 1 μm to 300 μm, 3 μm to 100 μm, 5 μm to 60 μm, or 10 μm to 30 μm. If the thickness of the photosensitive resin layer is 1 μm or more, the film strength becomes higher. If the thickness of the photosensitive resin layer is 300 μm or less, the resolution becomes higher.

〈Protective layer〉

The photosensitive resin laminate may have a photosensitive resin layer on a supporting layer, and further have a protective layer on the photosensitive resin layer. An important characteristic of the protective layer used in the photosensitive resin laminate is that its adhesion to the photosensitive resin layer is sufficiently smaller than that of the supporting layer, and can be easily peeled off. As the protective layer, a protective film such as a polyethylene film or a polypropylene film can be used. A film with excellent peelability described in Japanese Patent Publication No. 59-202457 can also be used. The film thickness of the protective layer is preferably 10 μm to 100 μm, more preferably 10 μm to 50 μm.

Sometimes there is a gel called fisheye on the surface of the polyethylene film. When the polyethylene film with fisheye is used as a protective film, the fisheye is sometimes transferred to the photosensitive resin layer. If the fisheye is transferred to the photosensitive resin layer, air is sometimes drawn in during lamination to form a gap, resulting in a defect in the resist pattern. From the viewpoint of preventing fisheyes, the material of the protective layer is preferably stretched polypropylene. As a specific example, ALPHAN E-200A manufactured by Prince Paper Co., Ltd. can be cited.

[Method for producing photosensitive resin laminate]

An example of a method for manufacturing a photosensitive resin laminate using the photosensitive resin composition of the present embodiment is described. The photosensitive resin laminate can be manufactured by sequentially stacking a support layer and a photosensitive resin layer, and a protective layer as required. For example, the photosensitive resin composition of the present embodiment is first mixed with a solvent that dissolves it to prepare a uniform preparation of the photosensitive resin composition. The preparation of the photosensitive resin composition is applied to the support layer using a rod coater or a roller coater, and then dried to remove the solvent, thereby enabling a photosensitive resin layer formed by the photosensitive resin composition to be stacked on the support layer. Then, a protective layer is laminated on the photosensitive resin layer as required, thereby enabling the manufacture of a photosensitive resin laminate.

[Method for producing resist pattern]

An example of a method for producing a resist pattern using the photosensitive resin laminate of the present embodiment is described. The method for producing a resist pattern of the present embodiment includes the following steps:

A step of exposing the photosensitive resin composition layer (photosensitive resin layer) of the present embodiment to light;

A heating step of heating the exposed photosensitive resin layer; and

A developing step of developing the heated photosensitive resin layer.

The photosensitive resin layer exposed in the exposure step is typically laminated on the substrate. The resist pattern forming method of the present embodiment may include a lamination step of laminating the photosensitive resin layer on the substrate before the exposure step.

Examples of the anti-etching pattern include patterns of printed circuit boards, semiconductor elements, printed plates, liquid crystal display panels, touch panels, flexible substrates, lead frame substrates, COF (chip on film) substrates, semiconductor package substrates, transparent electrodes for liquid crystals, TFT wiring for liquid crystals, electrodes for PDP (plasma display panel), and the like.

〈Lamination process〉

In the lamination process, a photosensitive resin layer is formed on a substrate using a laminator. Specifically, when the photosensitive resin laminate has a protective layer, the protective layer is peeled off and then the photosensitive resin layer is heated and pressed onto the substrate surface using a laminator for lamination. Examples of the material of the substrate include copper, stainless steel (SUS), glass, indium tin oxide (ITO), and the like.

The photosensitive resin layer can be laminated only on one side of the substrate surface, or can be laminated on both sides as needed. The heating temperature during lamination is usually 40°C to 160°C. By performing heat pressing during lamination twice or more, the adhesion of the obtained resist pattern to the substrate can also be improved. During heat pressing, a two-stage laminator with two rollers can be used, or the laminate of the substrate and the photosensitive resin layer can be repeatedly passed through the rollers for pressing.

〈Exposure process〉

In the exposure process, the photosensitive resin layer is exposed. Examples of the exposure method include: an exposure method in which a mask film having a desired wiring pattern is closely attached to a support layer and an active light source is used for exposure; an exposure method based on direct drawing of a desired wiring pattern, i.e., a drawing pattern; and an exposure method based on projecting an image of a photomask through a lens.

As the exposure method, an exposure method based on direct drawing of a drawing pattern or an exposure method in which an image of a photomask is projected through a lens is preferred, and an exposure method based on direct drawing of a drawing pattern is more preferred. The advantages of the photosensitive resin composition described in this embodiment are more significant in an exposure method based on direct drawing of a drawing pattern or an exposure method in which an image of a photomask is projected through a lens, and are particularly significant in an exposure method based on direct drawing of a drawing pattern.

In the case where the exposure process is an exposure method based on direct drawing, a laser having a central wavelength of less than 390nm or a laser having a central wavelength of 390nm or more is preferred. A laser having a central wavelength of 350nm or more and 380nm or a laser having a central wavelength of 400nm or more and 410nm or less is more preferred. It is preferably performed by a method of exposing using a first laser having a central wavelength of less than 390nm and a second laser having a central wavelength of 390nm or more. In addition, it is more preferred that the central wavelength of the first laser is 350nm or more and 380nm or less, and the central wavelength of the second laser is 400nm or more and 410nm or less.

〈Heating process〉

In the heating process, the exposed photosensitive resin is heated (heating after exposure). The heating temperature is preferably 30°C to 150°C, more preferably 60°C to 120°C. By implementing this heating process, the resolution and adhesion are improved. As the heating method, hot air, infrared rays, far infrared rays, a constant temperature bath, a heating plate, a hot air dryer, an infrared dryer or a hot roller can be used. If the heating method is a hot roller, it can be processed in a short time, so it is preferred, and more preferably two or more hot rollers.

The time from exposure to heating, more strictly speaking, the time from the time of stopping exposure to the time of starting heating is preferably within 15 minutes or within 10 minutes. The time from the time of stopping exposure to the time of starting heating can be 10 seconds or more, 20 seconds or more, 30 seconds or more, 1 minute or more, 2 minutes or more, 3 minutes or more, 4 minutes or more, or 5 minutes or more.

〈Development process〉

In the development step, the photosensitive resin layer is developed. For example, after exposure, the support layer on the photosensitive resin layer is peeled off, and then the unexposed portion is developed and removed using an alkaline aqueous developer, thereby forming a resist pattern on the substrate.

As the alkaline aqueous solution, an aqueous solution of _Na2CO3 or _K2CO3 is used. The alkaline aqueous solution is appropriately selected depending on the characteristics of the photosensitive resin layer, and an aqueous _Na2CO3 solution having a concentration of about 0.2% to 2 _% by mass and a _temperature of about 20°C to 40°C is _preferred .

[Method for manufacturing circuit board]

A circuit board can be manufactured using a substrate having a resist pattern formed by the above method. The method for manufacturing a circuit board of this embodiment includes a circuit forming step of forming a circuit board by etching or plating the substrate having the resist pattern of this embodiment.

〈Circuit Formation Process〉

In the circuit forming step, a circuit is formed by etching or plating a substrate having a resist pattern. Specifically, a substrate surface exposed by development (eg, a copper surface of a copper-clad laminate) is etched or plated to produce a conductor pattern.

〈Peeling process〉

The manufacturing method of the circuit substrate of the present embodiment may further include a stripping step of stripping the resist pattern from the substrate after the circuit forming step. The resist pattern is stripped from the substrate using an appropriate stripping solution. As the stripping solution, for example, an alkaline aqueous solution and an amine stripping solution can be cited. However, the resist pattern formed by the photosensitive resin composition of the present invention after exposure and heating shows good stripping properties for the amine stripping solution, and the excessive miniaturization of the stripping sheet is suppressed. Therefore, if an amine stripping solution is used as the stripping solution, the advantageous effects of the present invention are better exerted.

The amine contained in the amine stripping liquid may be an inorganic amine or an organic amine. Examples of the inorganic amine include ammonia, hydroxylamine, and hydrazine. Examples of the organic amine include ethanolamine, propanolamine, alkylamine, cyclic amine, and quaternary ammonium salt.

Examples of ethanolamines include monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-ethylethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, and aminoethoxyethanol. Examples of propanolamines include 1-amino-2-propanol, 2-amino-2-methyl-1-propanol, and 2-amino-2-methyl-1,3-propanediol. Examples of alkylamines include monomethylamine, dimethylamine, trimethylamine, ethyleneamine, ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenetetramine, and tetraethylenepentamine. Examples of cyclic amines include choline and morpholine. Examples of quaternary ammonium salts include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, N,N,N-triethyl-N-(2-hydroxyethyl)ammonium hydroxide, and N,N-diethyl-N,N-di(2-hydroxyethyl)ammonium hydroxide.

The amine-based stripping agent used in the present invention may be an aqueous solution containing one or more of the above-exemplified amines. The concentration of the amine in the aqueous solution can be appropriately set depending on the purpose, the composition of the photosensitive resin layer, the development conditions, and the like.

The amine-based release agent used in the present invention may further contain additives generally used in release agents, such as a surfactant, a defoaming agent, a pH adjuster, an antiseptic, an anti-reattachment agent, and the like.

The peeling step is performed at a temperature of, for example, 0°C to 100°C, preferably room temperature (23°C) to 50°C, for, for example, 1 second to 1 hour, preferably 10 seconds to 10 minutes.

After the stripping step, the substrate from which the resist pattern has been removed may be washed with, for example, pure water, as desired.

The photosensitive resin laminate of this embodiment is a photosensitive resin laminate suitable for manufacturing conductor patterns such as printed circuit boards, flexible substrates, lead frame substrates, touch panel substrates, COF substrates, semiconductor package substrates, transparent electrodes for liquid crystals, wiring for liquid crystal TFTs, and electrodes for PDPs.

Example

Hereinafter, although embodiment of this invention is demonstrated concretely by an Example and a comparative example, this invention is not limited to these Examples and comparative examples.

[Examples 1 to 8 and Comparative Examples 1 to 4]

<Production of photosensitive resin laminate>

As shown in Tables 1 to 3 described later, each component (wherein the amount of each component represents the amount of compounding (parts by mass) calculated as the solid content) is fully stirred and mixed to obtain a photosensitive resin composition preparation liquid. In Tables 2 and 3, the I value of the binder refers to the I value calculated as a mixture of alkali-soluble polymers represented by symbols A-1 to A-3. A 16 μm thick polyethylene terephthalate film (manufactured by Toray Industries, Inc., FB-40) was used as a supporting film, and the preparation liquid was evenly applied on its surface using a rod coater, and dried in a dryer at 95°C for 3 minutes to form a photosensitive resin composition layer. The dry thickness of the photosensitive resin composition layer is 25 μm. Next, a 19 μm thick polyethylene film (manufactured by Tamapoly, GF-818) was attached as a protective layer on the surface of the photosensitive resin composition layer on the side where the polyethylene terephthalate film was not laminated to obtain a photosensitive resin laminate.

〈Substrate leveling〉

As a substrate for evaluating image properties, a 0.4 mm thick copper-clad laminate on which a 35 μm rolled copper foil was laminated was jet-washed and polished using a grinding agent (manufactured by Uji Denka Kogyo Co., Ltd., #400) at a jet pressure of 0.2 MPa, and then the substrate surface was cleaned with a 10 mass % H ₂ SO ₄ aqueous solution.

<laminated>

While peeling off the polyethylene film (protective layer) of the photosensitive resin laminate, the photosensitive resin laminate was laminated on the copper-clad laminate preheated to 50° C. using a hot roll laminator (AL-700 manufactured by Asahi Kasei Corporation) at a roll temperature of 105° C. The air pressure was 0.35 MPa and the lamination speed was 1.5 m/min.

<exposure>

The evaluation substrate was exposed 2 hours after lamination using a direct drawing exposure machine (Nuvogo 1000 manufactured by ORBOTECH, light source: 375 nm (30%) + 405 nm (70%)) using a Stouffer 41-step step exposure meter. The exposure was performed at an exposure amount that allowed the maximum residual film level to reach 18 levels during exposure and development using the Stouffer 41-step step exposure meter as a mask.

〈Post-exposure heating〉

The evaluation substrate was heated 1 minute after exposure using a hot roller laminator (manufactured by Asahi Kasei Corporation, AL-700). The roller temperature was set to 105°C, the air pressure was set to 0.30 MPa, and the lamination speed was set to 1.5 m/min. In addition, a separately prepared evaluation substrate was heated in the same manner 7 minutes after exposure. It should be noted that if the time after exposure is extended, the heating effect is reduced, so heating is usually performed about 1 minute after exposure. Therefore, the heating after 7 minutes of exposure in this embodiment is a very severe condition.

<development>

After the polyethylene terephthalate film (support layer) was peeled off, an alkali developer (manufactured by Fuji Kiko Co., Ltd., developer for dry films) was used to spray a 1 mass % Na ₂ CO ₃ aqueous solution at 30° C. for a predetermined time for development. The development spray time was set to twice the shortest development time, and the water washing spray time after development was set to three times the shortest development time. At this time, the shortest time required for the photosensitive resin layer in the unexposed portion to be completely dissolved was set to the shortest development time.

〈Image Evaluation〉

The minimum line width of a pattern in which the mask pattern L/S=X μm/200 μm was normally formed was measured using an optical microscope. This measurement was performed for 8 lines, and the average value of the 8 line widths was determined as an index of adhesion. Adhesion was evaluated based on the following criteria.

A: The minimum close line width of independent patterns is less than 9μm

B: The minimum close line width of the independent pattern is 9 μm or more and less than 10 μm

C: The minimum close line width of the independent pattern is 10 μm or more and less than 11 μm

D: The minimum close line width of the independent pattern is 11μm or more

The materials used in Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 1 below, and the results are shown in Tables 2 and 3 below.

[Table 1]

[Table 2]

[Table 3]

[Examples 9 to 16 and Comparative Examples 5 to 8]

<Production of photosensitive resin laminate>

As shown in Tables 4 to 6 described later, each component (wherein the amount of each component represents the amount (parts by mass) of the solid content) is fully stirred and mixed to obtain a photosensitive resin composition preparation liquid. In Tables 5 and 6, the sp value (MPa ^1/2 ) of the binder represents the sp value of the mixture of the alkali-soluble polymers represented by symbols A-1 to A-3. A 16 μm thick polyethylene terephthalate film (FB-40 manufactured by Toray Industries, Inc.) was used as a supporting film, and the preparation liquid was evenly applied on its surface using a bar coater, and dried in a dryer at 95°C for 3 minutes to form a photosensitive resin composition layer. The dry thickness of the photosensitive resin composition layer is 25 μm. Next, a 19 μm thick polyethylene film (GF-818 manufactured by TAMAPOLY Co., Ltd.) was attached as a protective layer on the surface of the photosensitive resin composition layer on the side where the polyethylene terephthalate film was not laminated to obtain a photosensitive resin laminate.

〈Substrate leveling〉

As a substrate for evaluating image properties, a 0.4 mm thick copper-clad laminate on which a 35 μm rolled copper foil was laminated was jet-washed and polished using a grinding agent (manufactured by Uji Denka Kogyo Co., Ltd., #400) at a jet pressure of 0.2 MPa, and then the substrate surface was cleaned with a 10 mass % H ₂ SO ₄ aqueous solution.

<laminated>

While peeling off the polyethylene film (protective layer) of the photosensitive resin laminate, the photosensitive resin laminate was laminated on the copper-clad laminate preheated to 50° C. using a hot roll laminator (AL-700 manufactured by Asahi Kasei Corporation) at a roll temperature of 105° C. The air pressure was 0.35 MPa and the lamination speed was 1.5 m/min.

<exposure>

The evaluation substrate was exposed 2 hours after lamination using a direct drawing exposure machine (Nuvogo 1000 manufactured by ORBOTECH, light source: 375 nm (30%) + 405 nm (70%)) using a Stouffer 41-step step exposure meter. The exposure was performed at an exposure amount that allowed the maximum residual film level to reach 18 levels during exposure and development using the Stouffer 41-step step exposure meter as a mask.

〈Post-exposure heating〉

The evaluation substrate was heated 1 minute after exposure using a hot roller laminator (manufactured by Asahi Kasei Corporation, AL-700). The roller temperature was set to 105°C, the air pressure was set to 0.30 MPa, and the lamination speed was set to 1.5 m/min. In addition, a separately prepared evaluation substrate was heated in the same manner 7 minutes after exposure. It should be noted that if the time after exposure is extended, the heating effect is reduced, so heating is usually performed about 1 minute after exposure. Therefore, the heating after 7 minutes of exposure in this embodiment is a very severe condition.

<development>

After the polyethylene terephthalate film (support layer) was peeled off, an alkali developer (manufactured by Fuji Kiko Co., Ltd., developer for dry films) was used to spray a 1 mass % Na ₂ CO ₃ aqueous solution at 30° C. for a predetermined time for development. The development spray time was set to twice the shortest development time, and the water washing spray time after development was set to three times the shortest development time. At this time, the shortest time required for the photosensitive resin layer in the unexposed portion to be completely dissolved was set to the shortest development time.

〈Image Evaluation〉

The minimum line width of a pattern in which the mask pattern L/S=X μm/200 μm was normally formed was measured using an optical microscope. This measurement was performed for 8 lines, and the average value of the 8 line widths was determined as an index of adhesion. Adhesion was evaluated based on the following criteria.

A: The minimum close line width of independent patterns is less than 9μm

B: The minimum close line width of the independent pattern is 9 μm or more and less than 10 μm

C: The minimum close line width of the independent pattern is 10 μm or more and less than 11 μm

D: The minimum close line width of the independent pattern is 11μm or more

The materials used in Examples 9 to 16 and Comparative Examples 5 to 8 are shown in Table 4 below, and the results are shown in Tables 5 and 6 below.

[Table 4]

[Table 5]

[Table 6]

[Examples 17 to 24 and Comparative Example 9]

<Determination of weight average molecular weight or number average molecular weight of polymer>

The weight average molecular weight (Mw) or number average molecular weight (Mn) of the polymer was determined in terms of polystyrene by a gel permeation chromatograph (GPC) manufactured by JASCO Corporation (pump: Gulliver, PU-1580 type, columns: four Shodex (registered trademark) (KF-807, KF-806M, KF-806M, KF-802.5) manufactured by Showa Denko Co., Ltd., connected in series, mobile layer solvent: tetrahydrofuran, using a calibration curve based on a polystyrene standard sample (Shodex STANDARD SM-105 manufactured by Showa Denko Co., Ltd.). In addition, the dispersion of the polymer was calculated as the ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn).

<Production of photosensitive resin laminate>

As shown in Tables 7 and 8 described later, each component (wherein the amount of each component represents the amount of compounding (parts by mass) based on the solid content. "A-1 content" represents the content (mass %) of component A-1 shown in Table 7 relative to the solid content in the photosensitive resin composition) and a solvent are fully stirred and mixed to obtain a photosensitive resin composition preparation liquid. A 16 μm thick polyethylene terephthalate film (manufactured by Toray Industries, Inc., FB-40) was used as a supporting film, and the preparation liquid was evenly applied on its surface using a rod coater, and dried in a dryer at 95° C. for 3 minutes to form a photosensitive resin composition layer. The dry thickness of the photosensitive resin composition layer was 25 μm. Next, a 19 μm thick polyethylene film (manufactured by TAMAPOLY, GF-818) was attached as a protective layer on the surface of the photosensitive resin composition layer on the side where the polyethylene terephthalate film was not laminated to obtain a photosensitive resin laminate.

〈Substrate leveling〉

As a substrate for evaluating image properties, a 0.4 mm thick copper-clad laminate laminated with a 35 μm rolled copper foil was jet-washed and polished using a grinding agent (#400 manufactured by Uji Denka Kogyo Co., Ltd.) at a jet pressure of 0.2 MPa, and then the substrate surface was cleaned with a 10 mass % H ₂ SO ₄ aqueous solution.

<laminated>

While peeling off the polyethylene film (protective layer) of the photosensitive resin laminate, the photosensitive resin laminate was laminated on the copper-clad laminate preheated to 50° C. using a hot roll laminator (AL-700 manufactured by Asahi Kasei Corporation) at a roll temperature of 105° C. The air pressure was 0.35 MPa and the lamination speed was 1.5 m/min.

<exposure>

The evaluation substrate was exposed 2 hours after lamination using a direct drawing exposure machine (Nuvogo 1000 manufactured by ORBOTECH, light source: 375 nm (30%) + 405 nm (70%)) using a Stouffer 41-step step exposure meter. The exposure was performed at an exposure amount that allowed the maximum residual film level to reach 18 levels during exposure and development using the Stouffer 41-step step exposure meter as a mask.

〈Post-exposure heating〉

The evaluation substrate was heated 7 minutes after exposure using a hot roll laminator (manufactured by Asahi Kasei Corporation, AL-700). The roll temperature was set to 105°C, the air pressure was set to 0.30 MPa, and the lamination speed was set to 1 m/min. It should be noted that if the time after exposure is extended, the heating effect gradually disappears, so heating is usually performed about 1 minute after exposure. Therefore, heating after 7 minutes of exposure in this example is a very severe condition.

<development>

After the polyethylene terephthalate film (support layer) was peeled off, an alkali developer (manufactured by Fuji Kiko Co., Ltd., developer for dry films) was used to spray a 1 mass % Na ₂ CO ₃ aqueous solution at 30° C. for a predetermined time for development. The development spray time was set to twice the shortest development time. The water washing spray time after development was set to three times the shortest development time. At this time, the shortest time required for the photosensitive resin layer in the unexposed portion to be completely dissolved was set to the shortest development time.

〈Image Evaluation〉

The minimum line width of a pattern in which the mask pattern L/S=X μm/200 μm was normally formed was measured using an optical microscope. This measurement was performed for 8 lines, and the average value of the 8 line widths was determined as the value of adhesion.

The materials used in Examples 17 to 23 and Comparative Example 9 are shown in Table 7 below, and the results are shown in Table 8 below.

[Table 7]

[Table 8]

It is clear from the results of Tables 7 and 8 that the results of image quality evaluation are excellent in the Examples falling within the technical feature range of the present invention, as compared with the Comparative Examples falling outside the scope of the present invention.

The heating condition after exposure in this embodiment is heating after 7 minutes of exposure, so it is a very harsh condition. For example, the adhesion of the compositions of Example 17 and Comparative Example 9 when developed without heating after exposure is 10.6μm. In other words, in the composition of Comparative Example 9, no effect was observed in the heating after 7 minutes of exposure, but Example 23 can improve the adhesion even under very harsh conditions. In addition, under the condition of heating after 1 minute of exposure, the compositions of Example 23 and Comparative Example 9 can both obtain a 9.0μm adhesion.

According to the above results, even when the adhesion is good under the usual heating conditions after exposure, the adhesion is not improved under the harsh conditions of heating 7 minutes after exposure in this embodiment. However, the photosensitive resin composition of the present invention having a specific composition can improve the adhesion for the first time under the harsh heating conditions after exposure. Thus, when manufacturing a circuit substrate, good adhesion can be obtained even if the time after exposure becomes long, so that a high-precision circuit pattern can be stably formed.

[Examples 24 to 38 and Comparative Examples 10 to 11]

<Determination of Weight Average Molecular Weight of Polymer>

The weight average molecular weight (Mw) of the polymer was determined as a polystyrene-equivalent value by gel permeation chromatography (GPC) under the following conditions.

Measuring device: Gel permeation chromatography (GPC) manufactured by JASCO Corporation

Pump: Gulliver PU-1580 manufactured by Nippon SCOP

Column: Showa Denko Co., Ltd., Shodex (registered trademark) KF-807, KF-806M, KF-806M and KF-802.5 four in series

Mobile phase solvent: tetrahydrofuran

Standard sample: Shodex STANDARD SM-105 manufactured by Showa Denko K.K.

<Production of photosensitive resin laminate>

The photosensitive resin composition prepared in each example and comparative example was uniformly coated on the surface of the polyethylene terephthalate film (FB-40, 16 μm thick, manufactured by Toray Industries, Inc.) as a support layer using a bar coater, and dried in a dryer at 95°C for 3 minutes to form a photosensitive resin layer. The dry thickness of the photosensitive resin layer was 25 μm. Next, a polyethylene film (GF-818, 19 μm thick, manufactured by TAMAPOLY Co., Ltd.) was attached as a protective layer to the surface of the side of the photosensitive resin layer on which the polyethylene terephthalate film was not laminated, thereby obtaining a photosensitive resin laminate.

〈Substrate leveling〉

As the substrate, a 0.4 mm thick copper-clad laminate laminated with a 35 μm thick rolled copper foil was used. The copper-clad laminate was spray-washed and polished using a grinding agent (manufactured by Uji Denka Kogyo Co., Ltd., #400) at a spray pressure of 0.2 MPa, and then surface-cleaned with a 10 mass % H ₂ SO ₄ aqueous solution to level the substrate surface.

<laminated>

A photosensitive resin laminate was laminated on a copper-clad laminate preheated to 50° C. using a hot roll laminator (AL-700 manufactured by Asahi Kasei Corporation) while peeling off the polyethylene film (protective layer) to obtain an evaluation substrate. At this time, the roll temperature was 105° C., the air pressure was 0.35 MPa, and the lamination speed was 1.5 m/min.

<exposure>

The evaluation substrate was exposed 2 hours after lamination using a direct drawing exposure machine (Nuvogo Fine 10 manufactured by ORBOTECH, light source: 375 nm (30%) + 405 nm (70%)) using a Stouffer 41-step step exposure meter. The exposure was performed at an exposure amount at which the highest residual film level during exposure and development was 19 levels using the Stouffer 41-step step exposure meter as a mask.

〈Post-exposure heating〉

The evaluation substrate was heated 1 minute after exposure using a hot roll laminator (AL-700 manufactured by Asahi Kasei Corporation) to obtain a cured film of the photosensitive resin layer in the exposed portion at a roll temperature of 105° C., an air pressure of 0.30 MPa, and a lamination speed of 1.5 m/min.

<development>

After the polyethylene terephthalate film (support layer) was peeled off from the evaluation substrate after exposure and heating, an alkali developer (manufactured by Fuji Kiko Co., Ltd., developer for dry films) was used to spray a 1 mass % Na ₂ CO ₃ aqueous solution at 30°C and pure water in sequence for a predetermined time, respectively, to perform development. The development spray time was set to twice the shortest development time, and the water washing spray time after development was set to three times the shortest development time. Here, the shortest development time refers to the shortest time required for the photosensitive resin layer in the unexposed portion to be completely dissolved.

〈Adhesion Evaluation〉

In a test pattern of lines and spaces with a constant space width of 200 μm and a variable line width, the minimum line width normally formed was measured using an optical microscope. This measurement was performed for 8 sets of test patterns, and the average value was used as an indicator of adhesion.

〈Evaluation of peeling time〉

The evaluation substrate after lamination for 2 hours was exposed with a solid pattern of 5 cm in length and 3 cm in width. The evaluation substrate after exposure for 1 minute was heated using a hot roller laminator (manufactured by Asahi Kasei Corporation, AL-700). Next, development was performed at twice the minimum development time, and the water washing spray time after development was set to 3 times the shortest development time to obtain an evaluation sample. As a stripping solution, a mixed aqueous solution of R-100S (12 vol%) and R-101 (4 vol%) manufactured by Ryoko Chemical Co., Ltd. was adjusted to 50°C for use. The evaluation sample was immersed in the stripping solution, and the time until the cured film was stripped from the substrate was recorded. This time was taken as the stripping time and evaluated according to the following criteria.

A (good): peeling time is 45 seconds or less

B (pass): peeling time is more than 45 seconds and less than 50 seconds

C (bad): peeling time exceeds 50 seconds

<Evaluation of peeling piece size>

According to the above-mentioned peeling time evaluation, the evaluation sample was immersed in a peeling liquid, the size of the cured film peeled from the substrate was observed, and the evaluation was performed according to the following criteria.

AA (excellent): The peeling piece size is 1 cm square or more

A (good): The peeling piece size is 7 mm square or more and less than 1 cm square

B (qualified): The peeling piece size is 3 mm square or more and less than 7 mm square

C (bad): The peeling piece size is less than 3 mm square

As (A) an alkali-soluble polymer, (B) a compound having an ethylenically unsaturated double bond and (C) a photopolymerization initiator, and as optional additives (D) a photosensitizer, a colorant and a stabilizer, the components of the types and amounts (parts by mass in terms of solid content) listed in Table 1 and ethanol as a solvent were mixed and stirred sufficiently to prepare a photosensitive resin composition formulation having a solid content concentration of 55% by mass.

The materials used in Examples 24 to 38 and Comparative Examples 10 to 11 are shown in Table 9 below, and the results are shown in Tables 10 to 12 below.

[Table 9]

[Table 10]

[Table 11]

[Table 12]

The results of Tables 10 to 12 confirm that the Examples using the photosensitive resin composition of the present invention are superior in at least one of adhesion, and preferably both of the peeling time and peeling piece size using an amine-based peeling solution, as compared to Comparative Examples outside the scope of the present invention.

Claims (27)

1. A photosensitive resin composition, characterized in that, based on the total solid content of the photosensitive resin composition, it contains the following components: (A) 10 to 90% by mass of an alkali-soluble polymer, (B) 5 to 70% by mass of a compound having an ethylenically unsaturated double bond, and (C) 0.01% to 20% by mass of a photopolymerization initiator, The photosensitive resin composition comprises, as the alkali-soluble polymer (A), 3% by mass or more of an alkali-soluble polymer (A-1) based on the total solid content mass in the photosensitive resin composition, wherein the alkali-soluble polymer (A-1) comprises 55% by mass or more of a structural unit derived from styrene and/or a styrene derivative as a monomer component and 27% by mass or more of a structural unit derived from (meth)acrylic acid as a monomer component. 2 . The photosensitive resin composition according to claim 1 , wherein the photosensitive resin composition contains 10% by mass or more of the alkali-soluble polymer (A-1) based on the total solid content mass in the photosensitive resin composition. 3 . The photosensitive resin composition according to claim 1 , wherein the alkali-soluble polymer (A-1) contains 58% by mass or more of a structural unit derived from styrene and/or a styrene derivative as a monomer component. 4 . The photosensitive resin composition according to claim 1 , wherein the alkali-soluble polymer (A-1) contains 29% by mass or more of a structural unit derived from (meth)acrylic acid as a monomer component. 5 . 5 . The photosensitive resin composition according to claim 1 , wherein the alkali-soluble polymer (A-1) further comprises a structural unit derived from benzyl (meth)acrylate as a monomer component. 6 . The photosensitive resin composition according to claim 1 , wherein the (C) photopolymerization initiator comprises a hexaarylbiimidazole and an anthracene compound. 7 . The photosensitive resin composition according to claim 6 , wherein the anthracene compound is an anthracene derivative having an optionally substituted alkoxy group having 1 to 40 carbon atoms and/or an optionally substituted aryl group having 6 to 40 carbon atoms at the 9- and/or 10-positions. 8 . The photosensitive resin composition according to claim 6 , wherein the anthracene compound is at least one selected from the group consisting of 9,10-diphenylanthracene, 9,10-dibutoxyanthracene, and 9,10-diethoxyanthracene. 9. A photosensitive resin composition, characterized in that, based on the total solid content of the photosensitive resin composition, it comprises the following components: (A) 10 to 90% by mass of an alkali-soluble polymer, (B) 5 to 70% by mass of a compound having an ethylenically unsaturated double bond, and (C) 0.01% to 20% by mass of a photopolymerization initiator, The photosensitive resin composition comprises, as the alkali-soluble polymer (A), 3% by mass or more of an alkali-soluble polymer (A-1) based on the total solid content mass in the photosensitive resin composition, wherein the alkali-soluble polymer (A-1) comprises 52% by mass or more of a structural unit derived from styrene and/or a styrene derivative as a monomer component, comprises 25% by mass or more of a structural unit derived from (meth)acrylic acid as a monomer component, and comprises a structural unit derived from benzyl (meth)acrylate as a monomer component. 10 . The photosensitive resin composition according to claim 9 , wherein the photosensitive resin composition contains 10% by mass or more of the alkali-soluble polymer (A-1) based on the total solid content mass in the photosensitive resin composition. 11 . The photosensitive resin composition according to claim 9 , wherein the alkali-soluble polymer (A-1) contains 55% by mass or more of a structural unit derived from styrene and/or a styrene derivative as a monomer component. 12 . The photosensitive resin composition according to claim 11 , wherein the alkali-soluble polymer (A-1) contains 58% by mass or more of a structural unit derived from styrene and/or a styrene derivative as a monomer component. 13 . The photosensitive resin composition according to claim 9 , wherein the alkali-soluble polymer (A-1) contains 27% by mass or more of a structural unit derived from (meth)acrylic acid as a monomer component. 14 . The photosensitive resin composition according to claim 13 , wherein the alkali-soluble polymer (A-1) contains 29% by mass or more of a structural unit derived from (meth)acrylic acid as a monomer component. 15 . The photosensitive resin composition according to claim 9 , wherein the (C) photopolymerization initiator comprises a hexaarylbiimidazole and an anthracene compound. 16 . The photosensitive resin composition according to claim 15 , wherein the anthracene compound is an anthracene derivative having an optionally substituted alkoxy group having 1 to 40 carbon atoms and/or an optionally substituted aryl group having 6 to 40 carbon atoms at the 9- and/or 10-positions. 17 . The photosensitive resin composition according to claim 15 , wherein the anthracene compound is at least one selected from the group consisting of 9,10-diphenylanthracene, 9,10-dibutoxyanthracene, and 9,10-diethoxyanthracene. 18. The photosensitive resin composition according to any one of claims 1 to 3 and claims 9 to 12, which is a photosensitive resin composition for obtaining a cured resin by heating after exposure and then developing. 19. The photosensitive resin composition according to any one of claims 1 to 3 and claims 9 to 12, wherein the photosensitive resin composition is used to form a resist pattern for manufacturing a circuit board by etching or plating. 20. A method for forming a resist pattern, comprising the following steps: A step of exposing the layer of the photosensitive resin composition according to any one of claims 1 to 19; a heating step of heating the exposed layer of the photosensitive resin composition; and A developing step of developing the heated photosensitive resin composition layer. 21 . The method for forming a resist pattern according to claim 20 , wherein a heating temperature in the heating step is in a range of 30° C. to 150° C. 22. The method for forming a resist pattern according to claim 20 or 21, wherein the heating step is performed within 15 minutes after the light exposure is stopped. 23. The method for forming a resist pattern according to any one of claims 20 to 22, wherein the exposing step is performed by an exposure method based on direct drawing of a drawing pattern or an exposure method based on projecting an image of a photomask through a lens. 24 . The method for forming a resist pattern according to claim 23 , wherein the exposure step is performed by an exposure method based on direct drawing of a drawing pattern. 25 . The method for forming a resist pattern according to claim 24 , wherein the exposing step is performed by exposing with a first laser having a central wavelength of less than 390 nm and a second laser having a central wavelength of 390 nm or more. 26 . The method for forming a resist pattern according to claim 25 , wherein a central wavelength of the first laser light is greater than or equal to 350 nm and less than or equal to 380 nm, and a central wavelength of the second laser light is greater than or equal to 400 nm and less than or equal to 410 nm. 27 . A method for manufacturing a circuit substrate, comprising: manufacturing a resist pattern on a substrate by the method according to claim 20 , and etching or plating the substrate having the resist pattern to form the circuit substrate.