TW202526509A - Photosensitive resin laminate, method for forming photoresist pattern, and method for manufacturing wiring board with conductor pattern - Google Patents

Abstract

The present disclosure provides a photosensitive resin laminate which has a provisional support and a photosensitive resin layer that contains a photosensitive resin composition, wherein the photosensitive resin composition contains the following components: (A) an alkali-soluble polymer; (B) a photopolymerizable compound; and (C) a photopolymerization initiator. The alkali-soluble polymer (A) includes (A-1) a copolymer which has the following constituent unit: (a1) a constituent unit that is derived from a compound having two or more alcoholic hydroxyl groups and a (meth)acryloyl group.

Description

Photosensitive resin laminate, method for forming photoresist pattern, and method for manufacturing wiring board with conductor pattern

The present invention relates to a photosensitive resin laminate, a method for forming a photoresist pattern, and a method for manufacturing a wiring board having a conductive pattern.

The wiring patterns (hereinafter also referred to as "conductor patterns") on wiring boards and other components of electronic devices are generally produced using a photolithography process. This process, for example, includes the following steps: Laying a photosensitive resin layer on a substrate, followed by exposure and development to form a photoresist pattern; Etching or plating the substrate with the photoresist pattern to form a conductor pattern; and Removing the photoresist pattern from the substrate.

Patent Document 1 proposes a photosensitive resin composition comprising a binder polymer, a photopolymerizable compound, a photopolymerization initiator, and an anthracene-based sensitizer. The binder polymer comprises hydroxyalkyl (meth)acrylate units and styrene or styrene derivative units, with the styrene or styrene derivative unit content being 40% by mass or greater. Patent Document 1 describes the use of this photosensitive resin composition, which enables the formation of photoresist patterns with excellent adhesion and resolution. [Prior Art Document] [Patent Document]

[Patent Document 1] International Publication No. 2021/193232

[Technical Problems Solved by the Invention] In photolithography processes, not only are the photoresist pattern's adhesion and resolution required, but the photosensitive resin layer's developability and the resist pattern's strength also required to be excellent. However, Patent Document 1 still has room for improvement in terms of balancing and satisfying these requirements.

Therefore, the present invention aims to provide a photosensitive resin laminate that not only achieves high adhesion and resolution of the photoresist pattern, but also balances the developability of the photosensitive resin layer and the strength of the photoresist pattern, thereby satisfying all of these requirements. Furthermore, the present invention provides a method for forming a photoresist pattern using the photosensitive resin laminate, as well as a method for manufacturing a wiring board having a conductive pattern. [Technical Means]

One aspect of the present invention is as follows. [1] A photosensitive resin laminate having a temporary support and a photosensitive resin layer containing a photosensitive resin composition; and the aforementioned photosensitive resin composition contains the following components: (A) an alkali-soluble polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator; the aforementioned (A) alkali-soluble polymer contains a copolymer (A-1) having the following constituent units: (a1) a constituent unit derived from a compound having two or more alcoholic hydroxyl groups and (meth)acrylic groups; and (a3) a constituent unit derived from styrene, a styrene derivative, or benzyl (meth)acrylate. [2] The photosensitive resin laminate as described in item 1, wherein the aforementioned (a1) constituent unit derived from the aforementioned compound is glyceryl mono(meth)acrylate. [3] The photosensitive resin laminate as described in item 1 or 2, wherein the content of the aforementioned (a1) constituent unit in the aforementioned component (A) is 0.5 to 30% by mass. [4] The photosensitive resin laminate as described in any one of items 1 to 3, wherein the content of the aforementioned (a1) constituent unit in the aforementioned component (A) is 1.0 to 10% by mass. [5] The photosensitive resin laminate as described in any one of items 1 to 4, wherein the content of the aforementioned (a1) constituent unit in the aforementioned (A) component is 1.0 to 5.0 mass%. [6] The photosensitive resin laminate as described in any one of items 1 to 5, wherein the aforementioned (A-1) copolymer further comprises the following constituent units: (a2) a constituent unit derived from a compound having a carboxyl group and an ethylenically unsaturated bond. [7] The photosensitive resin laminate as described in any one of items 1 to 6, wherein the content of the aforementioned (a3) constituent unit in the aforementioned (A) component is 10 mass% or more. [8] The photosensitive resin laminate as described in any one of items 1 to 7, wherein the content of the (a3) constituent unit in the (A) component is 20 to 70% by mass. [9] The photosensitive resin laminate as described in any one of items 1 to 8, wherein the weight average molecular weight of the (A) component is 10,000 to 60,000. [10] The photosensitive resin laminate as described in any one of items 1 to 9, wherein the (B) component contains a compound having two ethylenically unsaturated bonds in one molecule. [11] The photosensitive resin laminate as described in any one of items 1 to 10, wherein the (C) component contains a hexaarylbiimidazole compound. [12] A photosensitive resin laminate as described in any one of items 1 to 11, wherein the total content of the aforementioned component (A), the aforementioned component (B), and the aforementioned component (C) is 90% by mass or more relative to the total solid content of the photosensitive resin composition. [13] A photosensitive resin laminate as described in any one of items 1 to 12, further comprising a protective film. [14] A photosensitive resin laminate for forming a conductive pattern, comprising the photosensitive resin laminate as described in any one of items 1 to 13. [15] A photosensitive resin laminate roll, which is formed by rolling up the photosensitive resin laminate described in any one of items 1 to 14. [16] A method for forming a photoresist pattern, which comprises the following steps: a step of laminating a photosensitive resin layer in the photosensitive resin laminate described in any one of items 1 to 14 on a substrate; a step of exposing the photosensitive resin layer; and a step of forming a photoresist pattern by developing the exposed photosensitive resin layer. [17] A method for manufacturing a wiring board having a conductive pattern, comprising the following steps: a step of laminating a photosensitive resin layer in a photosensitive resin laminate as described in any one of items 1 to 14 on a substrate; a step of exposing the photosensitive resin layer; a step of forming a photoresist pattern by developing the exposed photosensitive resin layer; and a step of etching or plating the substrate having the photoresist pattern formed thereon to form a conductive pattern on the substrate.

Furthermore, an aspect related to one aspect of the present invention is as follows. [1] A photosensitive resin laminate having a temporary support and a photosensitive resin layer containing a photosensitive resin composition; and the aforementioned photosensitive resin composition contains the following components: (A) an alkali-soluble polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator; the aforementioned (A) alkali-soluble polymer contains a copolymer (A-1) having the following constituent units: (a1) a constituent unit derived from a compound having two or more alcoholic hydroxyl groups and (meth)acryloyl groups. [2] The photosensitive resin laminate as described in item 1, wherein the aforementioned (a1) constituent unit derived from the aforementioned compound is glyceryl mono(meth)acrylate. [3] The photosensitive resin laminate as described in item 1 or 2, wherein the content of the aforementioned (a1) constituent unit in the aforementioned component (A) is 0.5 to 30% by mass. [4] The photosensitive resin laminate as described in any one of items 1 to 3, wherein the content of the aforementioned (a1) constituent unit in the aforementioned component (A) is 1.0 to 10% by mass. [5] The photosensitive resin laminate as described in any one of items 1 to 4, wherein the content of the aforementioned (a1) constituent unit in the aforementioned (A) component is 1.0 to 5.0 mass%. [6] The photosensitive resin laminate as described in any one of items 1 to 5, wherein the aforementioned (A-1) copolymer further comprises the following constituent units: (a2) a constituent unit derived from a compound having a carboxyl group and an ethylenically unsaturated bond. [7] The photosensitive resin laminate as described in any one of items 1 to 6, wherein the aforementioned (A-1) copolymer further comprises the following constituent units: (a3) a constituent unit derived from styrene, a styrene derivative, or benzyl (meth)acrylate. [8] The photosensitive resin laminate as described in item 7, wherein the content of the (a3) constituent unit in the (A) component is 20 to 70% by mass. [9] The photosensitive resin laminate as described in any one of items 1 to 8, wherein the weight average molecular weight of the (A) component is 10,000 to 60,000. [10] The photosensitive resin laminate as described in any one of items 1 to 9, wherein the (B) component contains a compound having two ethylenically unsaturated bonds in one molecule. [11] The photosensitive resin laminate as described in any one of items 1 to 10, wherein the (C) component contains a hexaarylbiimidazole compound. [12] A photosensitive resin laminate as described in any one of items 1 to 11, wherein the total content of the aforementioned component (A), the aforementioned component (B), and the aforementioned component (C) is 90% by mass or more relative to the total solid content of the photosensitive resin composition. [13] A photosensitive resin laminate as described in any one of items 1 to 12, further comprising a protective film. [14] A photosensitive resin laminate for forming a conductive pattern, comprising the photosensitive resin laminate as described in any one of items 1 to 13. [15] A photosensitive resin laminate roll, which is formed by rolling up the photosensitive resin laminate described in any one of items 1 to 14. [16] A method for forming a photoresist pattern, which comprises the following steps: a step of laminating a photosensitive resin layer in the photosensitive resin laminate described in any one of items 1 to 14 on a substrate; a step of exposing the photosensitive resin layer; and a step of forming a photoresist pattern by developing the exposed photosensitive resin layer. [17] A method for manufacturing a wiring board having a conductive pattern, comprising the following steps: a step of laminating a photosensitive resin layer of a photosensitive resin laminate as described in any one of items 1 to 14 on a substrate; a step of exposing the photosensitive resin layer; a step of forming a photoresist pattern by developing the exposed photosensitive resin layer; and a step of etching or plating the substrate having the photoresist pattern formed thereon to form a conductive pattern on the substrate. [Effects of the Invention]

The present invention provides a photosensitive resin laminate that not only achieves high adhesion and resolution of the photoresist pattern, but also balances the developability of the photosensitive resin layer and the strength of the photoresist pattern, achieving all of these goals. Furthermore, the present invention provides a method for forming a photoresist pattern using the photosensitive resin laminate, as well as a method for manufacturing a wiring board having a conductive pattern.

The present invention is not limited to this embodiment, and various modifications can be made within the scope of its gist.

In this specification, when there are multiple structures represented by the same symbol in the same formula, unless otherwise specified, the structures can be individually independent and selected, and can be the same or different from each other. When there are multiple structures represented by the same symbol in different formulas, unless otherwise specified, the structures can also be individually independent and selected, and can be the same or different from each other. In this specification, various measurements are performed based on the methods described in the embodiments unless otherwise specified. In this specification, the upper limit or lower limit of a numerical range described in a step-by-step manner can be replaced with the upper limit or lower limit of another corresponding numerical range described in a step-by-step manner, and further, can be replaced with the corresponding value described in the embodiments.

In this specification, "(meth)acrylic acid" means "acrylic acid" and/or "methacrylic acid"; "(meth)acrylate" means "acrylate" and/or "methacrylate"; and "(meth)acrylic acid" means "acrylic acid" and/or "methacrylic acid." A "compound containing a (meth)acryloyl group," for example, is referred to as a "(meth)acrylate compound." In this specification, the term "step" refers not only to individual steps but also to steps that cannot be clearly distinguished from other steps, as long as they achieve the function of the step. In the drawings, scales, shapes, and lengths may be exaggerated for clarity. In this specification, the "solid components" of a photosensitive resin composition refer to the components of the photosensitive resin composition other than the solvent.

In one embodiment, unless otherwise specified, the following terms have the following meanings: "Developability" refers to the developing performance of the photosensitive resin layer (photoresist); "Sensitivity" refers to the exposure sensitivity of the photosensitive resin layer (photoresist); "Adhesion" refers to the adhesion between the photoresist pattern and the substrate; "Resolution" refers to the resolution performance of the photoresist pattern; "Fine line strength" refers to the strength of the photoresist pattern.

[Photosensitive Resin Laminate] One aspect of this embodiment is a photosensitive resin laminate. The photosensitive resin laminate comprises a supporting film and a photosensitive resin layer containing a photosensitive resin composition; and the photosensitive resin composition comprises the following components: (A) an alkali-soluble polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator; the alkali-soluble polymer (A) comprises a copolymer (A-1) having the following constituent units: (a1) a constituent unit derived from a compound having two or more alcoholic hydroxyl groups and (meth)acryloyl groups.

Another aspect of this embodiment is a photosensitive resin laminate. The photosensitive resin laminate comprises a supporting film and a photosensitive resin layer containing a photosensitive resin composition; the photosensitive resin composition comprises the following components: (A) an alkali-soluble polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator; the alkali-soluble polymer (A) comprises a copolymer (A-1) having the following constituent units: (a1) a constituent unit derived from a compound having two or more alcoholic hydroxyl groups and (meth)acrylic groups, and (a3) a constituent unit derived from styrene, a styrene derivative, or benzyl (meth)acrylate. That is, the copolymer (A-1) comprises, in one embodiment: (a1) a constituent unit derived from a compound having two or more alcoholic hydroxyl groups and a (meth)acryl group. In another embodiment, in addition to (a1), the copolymer further comprises: (a3) a constituent unit derived from styrene, a styrene derivative, or benzyl (meth)acrylate.

In recent years, with the miniaturization of electronic devices and the increasing density of wiring within them, there has been a growing demand for photosensitive resin laminates capable of forming fine photoresist patterns with excellent properties. Examples of fine photoresist patterns with excellent properties include those with line widths of 7μm or less and excellent adhesion, resolution, and fine line strength. Furthermore, from the perspective of efficient production and use of photosensitive resin laminates, there is a desire for the photosensitive resin layer to exhibit excellent developability.

One approach to achieving the desired properties of the photosensitive resin layer and resist pattern involves controlling the constituent units and physical properties of component (A). From this perspective, to improve resolution and adhesion, the use of a copolymer as component (A) is conceivable. Such copolymers utilize highly hydrophobic monomers. However, this high hydrophobicity can reduce solubility in developer solutions, leading to decreased developability. To address this, a design could be developed that uses a compound containing a hydroxyl group as a copolymer component to impart hydrophilicity to the copolymer.

The inventors have focused on using a monomer containing two or more alcoholic hydroxyl groups as a copolymer component to form a (meth)acrylic resin copolymer. The presence of two or more alcoholic hydroxyl groups derived from the monomer in this copolymer allows for a copolymer with locally excellent hydrophilic properties, even when used in combination with a highly hydrophobic monomer. According to this embodiment, a photosensitive resin laminate is provided that, by controlling the constituent units and physical properties of component (A), balances the developability of the photosensitive resin layer and the strength of the resist pattern, achieving all of these benefits, in addition to maintaining photoresist pattern adhesion and resolution.

[Temporary Support] A temporary support is peeled off from the photosensitive resin layer before the exposure step or the development step. The temporary support is a layer or film used to support the photosensitive resin layer, preferably a transparent substrate that transmits the exposure light (active light). This substrate is sometimes referred to as a "support film" or "support," but in this specification, it is referred to as the "temporary support."

Examples of substrates that can be used as temporary supports, particularly transparent ones, include synthetic resins such as polyethylene, polypropylene, polycarbonate, and polyethylene terephthalate. Among them, polyethylene terephthalate (PET) is preferred as a temporary support due to its moderate flexibility and strength.

From the perspective of ensuring easy identification, the absorbance of the temporary support at a wavelength of 365 nm is preferably 0.3 or less, more preferably 0.2 or less, even more preferably 0.1 or less, and most preferably 0.08 or less (e.g., 0.080). The absorbance may also be 0 or greater.

A film with minimal internal foreign matter, such as a high-quality film, is preferably used as a temporary support. Specifically, examples of high-quality films include PET films synthesized using a Ti-based catalyst, PET films with a small diameter and low lubricant content, PET films containing lubricants only on one side, thin-film PET films, PET films with a smoothing treatment applied to at least one side, and PET films with a roughening treatment such as plasma treatment applied to at least one side. Using a high-quality film as a temporary support reduces the risk of foreign matter within the temporary support blocking the exposure light. This allows the photosensitive resin layer to be exposed to the exposure light more easily, resulting in improved resolution of the photosensitive resin laminate.

The thickness of the temporary support is preferably 5-25 μm, more preferably 6-20 μm. Thinner temporary supports tend to contain fewer internal foreign objects, thus preventing a decrease in resolution. On the other hand, if the thickness is less than 5 μm, it is prone to deformation in the winding direction due to tension during the coating and winding manufacturing steps, or to cracking due to microscopic scratches. As a result, the temporary support is likely to be insufficiently strong, and wrinkles may form in the photosensitive resin laminate when it is pressed onto the substrate.

At least one surface of the temporary support can be smoothed using a calendering device or the like. This can reduce the surface roughness of one surface of the support film, particularly the surface in contact with the photosensitive resin layer, making it easier to achieve the effects of the present invention.

From the perspective of improving the parallelism of light irradiating the photosensitive resin layer and achieving high resolution, the haze of the temporary support is preferably 0.01% to 1.5%, more preferably 0.01% to 1.2%, and even more preferably 0.01% to 0.95%.

[Photosensitive Resin Layer] The photosensitive resin layer contains a photosensitive resin composition. The photosensitive resin composition contains "(A) an alkali-soluble polymer," "(B) a compound having an ethylenically unsaturated bond," and "(C) a photopolymerization initiator." The photosensitive resin composition may optionally contain "(D) a dye" and/or "(E) other components." In this specification, (A) through (E) are sometimes referred to simply as "component (A)" through "component (E)." Each component (A) through (E), or the raw materials for each component, may be used alone or in combination.

From the perspective of facilitating the effects of this embodiment and being suitable for forming a conductive pattern, the total content of component (A), component (B), and component (C) relative to the total solid content of the photosensitive resin composition is preferably 90% by mass or more, more preferably 95% by mass or more.

The thickness of the photosensitive resin layer is preferably 3 to 100 μm, with a specific preferred thickness being 100 μm. A smaller thickness improves resolution, while a larger thickness improves the strength of the photosensitive resin layer. The thickness of the photosensitive resin layer can be, for example, 7 μm or greater, 15 μm or greater, 25 μm or greater, or 40 μm or greater. Alternatively, it can be 60 μm or less, or 50 μm or less.

The thickness of the photosensitive resin layer can be selected based on the composition and application of the photosensitive resin laminate, the composition and application of the photoresist pattern obtained using the photosensitive resin laminate, and the composition and application of the conductor pattern or electronic device produced using the photosensitive resin laminate. When plating a substrate with a photoresist pattern formed thereon, the thickness of the photosensitive resin layer is preferably 10-30 μm, more preferably 15-25 μm.

(Component (A): Alkali-soluble polymer) Component (A) is a polymer soluble in alkaline aqueous solutions, for example, a polymer having carboxyl groups.

Component (A) comprises a copolymer (A-1) having the following constituent units: (a1) constituent units derived from a compound having two or more alcoholic hydroxyl groups and (meth)acryloyl groups. Component (A) may comprise multiple copolymers, for example, multiple copolymers (A-1). Furthermore, it may comprise copolymers other than (A-1) copolymers (hereinafter referred to as "other copolymers"). When component (A) comprises multiple copolymers, the content of the repeating units in component (A) represents the weighted average of the ratios of the repeating units in each copolymer, weighted by the ratio of the content of each copolymer. Furthermore, when component (A) comprises multiple copolymers, the molecular weight and polydispersity of component (A) as a whole are preferably such that the weighted average, weighted by the ratio of the content of each copolymer, falls within the ranges described below.

The weight average molecular weight (Mw) of component (A) is preferably 5,000 to 500,000, more preferably 10,000 to 200,000, even more preferably 20,000 to 100,000, and particularly preferably 23,000 to 60,000. A weight average molecular weight (Mw) of component (A) of 5,000 or greater facilitates maintaining a uniform thickness of the photosensitive resin laminate and ensuring resistance to developer solutions. A weight average molecular weight (Mw) of component (A) of 500,000 or less facilitates maintaining the developability of the photosensitive resin laminate.

The dispersity (Mw/Mn), which is the ratio of the weight average molecular weight (Mw) of component (A) to the number average molecular weight (Mn) of component (A), is preferably 1.0 to 6.0.

The content of the constituent unit (a1) in component (A) is preferably 0.5% by mass or more from the viewpoint of excellent adhesion and fine line strength, and preferably 30% by mass or less from the viewpoint of excellent developability. From the same viewpoints, the content is more preferably 1.0 to 10% by mass, and even more preferably 1.0 to 5% by mass.

The content of the constituent units (a1) is also preferably selected so that the number of hydroxyl groups per 1g of component (A) falls within the specified range. To achieve excellent adhesion, the number of hydroxyl groups is preferably 0.050 mmol or greater; to achieve excellent developing properties, the number of hydroxyl groups is preferably 3.50 mmol or less. From the same perspective, the number of hydroxyl groups is more preferably 0.11 to 1.25 mmol, and even more preferably 0.20 to 0.65 mmol.

The number of hydroxyl groups is expressed by the following formula: Number of hydroxyl groups = (X × Y) / (Z × 100) {wherein, X represents the number of hydroxyl groups contained in the (a1) constituent unit, Y represents the content (mass %) of the (a1) constituent unit contained in the (A) component, and Z represents the molecular weight of the (a1) compound.} When the (a1) constituent unit or a constituent unit other than the (a1) constituent unit contains a compound having multiple hydroxyl groups, the individual compounds having hydroxyl groups can be referred to as Compounds 1 to n, and the number of hydroxyl groups can be expressed as follows: However, in the formula, _Xi represents the number of hydroxyl groups contained in compound i (i = 1 to n), _Yi represents the content (mass %) of compound i (i = 1 to n) contained in component (A), and _Zi represents the molecular weight of compound i (i = 1 to n).

From the perspective of the alkali solubility of component (A) and the proper development of the developing properties of the photosensitive resin composition, the acid value of component (A) is preferably 50 to 600 mgKOH/g. The acid value of component (A) may be 60 mgKOH/g or more, 80 mgKOH/g or more, 500 mgKOH/g or less, or 400 mgKOH/g or less. From the same perspective, the photosensitive resin composition preferably has an acid value of 20 to 300 mgKOH/g. From the same perspective, the acid value of the photosensitive resin composition may be 30 mgKOH/g or more, 40 mgKOH/g or more, 200 mgKOH/g or less, or 150 mgKOH/g or less.

The acid value is determined by dissolving approximately 1 g of precisely weighed sample in 100 mL of acetone and performing a neutralization titration with a 1 mol/L aqueous potassium hydroxide solution. Based on the amount of potassium hydroxide solution added, the acid value can be calculated using the following formula: Acid value (mgKOH/g) = 56.1 × {amount of 1 mol/L aqueous potassium hydroxide solution added (mL)} / {mass of precisely weighed sample (g)}. Neutralization titrations can be performed, for example, using the Hiranuma Automatic Titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd.

Component (A) may further contain the constituent unit (a3) described below. The content of the constituent unit (a3) in component (A) is preferably 10% by mass or greater to ensure excellent adhesion, and preferably 85% by mass or less to ensure excellent developability. From the same perspectives, this content is more preferably 20% to 80% by mass, and even more preferably 30% to 75% by mass.

The constituent units (a3) are preferably units derived from styrene, a styrene derivative, or benzyl (meth)acrylate. From the perspective of excellent adhesion, the constituent units derived from styrene are particularly preferred. The content of the constituent units derived from styrene in component (A) is preferably 10% by mass or greater, more preferably 20% by mass or greater, and even more preferably 30% by mass or greater. From the perspective of developing properties, the content of the constituent units derived from styrene can be 70% by mass or less, and even more preferably 65% by mass or less.

The content of component (A) relative to the total solid content of the photosensitive resin composition may be 10% by mass or greater, 20% by mass or greater, 25% by mass or greater, 30% by mass or greater, 35% by mass or greater, 40% by mass or greater, 45% by mass or greater, 50% by mass or greater, 55% by mass or greater, or 60% by mass or greater. Alternatively, this content may be 90% by mass or less, 80% by mass or less, 70% by mass or less, 60% by mass or less, or 50% by mass or less. A content of 90% by mass or less is preferred for easier control of developing time, while a content of 10% by mass or greater is preferred for excellent edge melting resistance.

(A-1) Copolymer (A-1) Copolymer comprises the following constituent units: (a1) constituent units derived from a compound having two or more alcoholic hydroxyl groups and (meth)acryloyl groups (in this specification, the "compound having two or more alcoholic hydroxyl groups and (meth)acryloyl groups" may be referred to simply as the "(a1) compound"). In this specification, "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. Furthermore, "constituent units derived from the (a1) compound" means constituent units formed by copolymerizing the (a1) compound. Furthermore, "constituent units derived from the (a1) compound" means constituent units having two or more alcoholic hydroxyl groups in the (a1) compound. In this specification, "a constituent unit derived from compound (a1)" may be referred to simply as "(a1) constituent unit." Furthermore, the number of alcoholic hydroxyl groups in compound (a1) or the (a1) constituent unit may be 5 or less, 4 or less, or 3 or less.

The weight average molecular weight (Mw) of the copolymer (A-1) is preferably 5,000 to 500,000, more preferably 10,000 to 200,000, even more preferably 20,000 to 100,000, and particularly preferably 23,000 to 60,000. A weight average molecular weight (Mw) of 5,000 or greater for the copolymer (A-1) facilitates maintaining a uniform thickness of the photosensitive resin laminate and ensuring resistance to developer solutions. A weight average molecular weight (Mw) of 500,000 or less for the copolymer (A-1) facilitates maintaining the developability of the photosensitive resin laminate.

The dispersity (Mw/Mn), which is the ratio of the weight average molecular weight (Mw) of the copolymer (A-1) to the number average molecular weight (Mn) of the copolymer (A-1), is preferably 1.0 to 6.0.

The content of the (A-1) copolymer is preferably 1-80% by mass, more preferably 1-70% by mass, even more preferably 5-60% by mass, and particularly preferably 10-55% by mass, relative to the total solids content of the photosensitive resin composition. A content of 5% or greater facilitates excellent adhesion and fine line strength. A content of 80% or less facilitates ensuring resistance to developer solutions. From a similar perspective, the content of the (A-1) copolymer is preferably 5% by mass or greater, more preferably 10% by mass or greater, and even more preferably 15% by mass or greater, relative to component (A). The photosensitive resin composition may contain one type of copolymer (A-1) or two or more different types of copolymers. When two or more different (A-1) copolymers are used, the above content refers to the total content of the two or more (A-1) copolymers (A-1).

(a1) Compound Examples of the (a1) compound include glycerol mono(meth)acrylate, 2-hydroxy-1-(hydroxymethyl)ethyl (meth)acrylate, 3,4-dihydroxybutyl (meth)acrylate, 2,4-dihydroxybutyl (meth)acrylate, 4,5-dihydroxypentyl (meth)acrylate, 2,3,4-trihydroxybutyl (meth)acrylate, and 2-hydroxy-3-(2-hydroxyethoxy) (meth)acrylate. Among these, glycerol mono(meth)acrylate is preferred as the (a1) compound.

Commercially available products of glycerol mono(meth)acrylate include Blemmer (registered trademark) GLM, Blemmer GLM-EX, and Blemmer GLM-R (all trade names, manufactured by NOF Corporation).

The proportion of the (a1) constituent unit in the (A-1) copolymer is preferably 0.5% by mass or greater from the perspective of excellent adhesion and fine line strength, and preferably 30% by mass or less from the perspective of excellent adhesion and resolution. From the same perspective, the proportion of the (a1) constituent unit is more preferably 1 to 10% by mass, and particularly preferably 1 to 5% by mass. The (A-1) copolymer may have a plurality of different (a1) constituent units. In this case, the total proportion of all constituent units corresponding to the (a1) constituent unit is preferably within the above range.

(a2) Compound The (A-1) copolymer preferably further comprises the following constituent units: (a2) constituent units derived from a compound having a carboxyl group and an ethylenically unsaturated bond (in this specification, the "compound having a carboxyl group and an ethylenically unsaturated bond" may be referred to simply as the "(a2) compound"). In this specification, the "constituent units derived from the (a2) compound" may be referred to simply as the "(a2) constituent units."

Examples of the compound (a2) include (meth)acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, and 4-vinylbenzoic acid. Among these, (meth)acrylic acid is preferred, and methacrylic acid is more preferred, from the perspective of excellent adhesion and resolution.

The proportion of the constituent units (a2) in the copolymer (A-1) is preferably 10 to 40 mass %, more preferably 15 to 35 mass %, and even more preferably 18 to 30 mass %, from the viewpoint of excellent developability and resolution.

(a3) Compound The (A-1) copolymer preferably further comprises the following constituent units: (a3) A constituent unit derived from styrene, a styrene derivative, or benzyl (meth)acrylate (In this specification, "styrene, a styrene derivative, or benzyl (meth)acrylate" may be referred to simply as "(a3) compound"). In this specification, "a constituent unit derived from (a3) compound" may be referred to simply as "(a3) constituent unit." Among the (a3) compounds, the styrene derivative may be a styrene derivative without a carboxyl group, such as 4-methylstyrene, 4-hydroxystyrene, 4-methoxystyrene, 4-chlorostyrene, and 4-(chloromethyl)styrene. Among these, styrene is preferred as the (a3) compound from the perspectives of excellent adhesion and resolution.

The proportion of the (a3) constituent units in the copolymer (A-1) is preferably 10% by mass or greater from the viewpoint of excellent developing properties and resolution, and preferably 85% by mass or less from the viewpoint of excellent developing properties. From the same viewpoint, the proportion of the (a3) constituent units is preferably 20 to 80% by mass, and more preferably 30 to 75% by mass.

Among the above-mentioned constituent units (a3), constituent units derived from styrene are preferred from the perspective of excellent adhesion. The content of constituent units derived from styrene in component (A) is preferably 10% by mass or greater, more preferably 20% by mass or greater, and even more preferably 30% by mass or greater. From the perspective of excellent developability, the content of constituent units derived from styrene can be 70% by mass or less, more preferably 65% by mass or less.

Other Monomers Copolymer (A-1) may contain constituent units derived from monomers other than the above-mentioned compounds (a1) to (a3) (hereinafter referred to as "other monomers").

Other monomers are compounds other than the compounds (a1) to (a3) above, for example, compounds having at least one ethylenically unsaturated bond in the molecule. Specific examples of other monomers include (meth)acrylates, vinyl alcohol, vinyl acetate, esters (e.g., (meth)acrylonitrile), N-phenylmaleimide, and maleic anhydride.

(Meth)acrylates are a concept that includes chain alkyl esters, cyclic alkyl esters, and compounds in which the hydrogen atoms in these ester compounds are replaced by hydroxyl groups. Examples of (meth)acrylates include benzyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, tertiary butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, n-tetradecyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, isoborneol (meth)acrylate, and dicyclopentanyl (meth)acrylate. Other monomers may include, for example, compounds having one alcoholic hydroxyl group and a (meth)acryloyl group.

Other Copolymers Component (A) may optionally contain other copolymers. Preferably, the other copolymers comprise units derived from monomers composed of at least one of the first monomers described below, or more preferably, comprise units derived from monomer components composed of at least one of the first monomers and at least one of the second monomers described below.

First Monomer The first monomer is a compound having a carboxyl group and an ethylenically unsaturated group in its molecule. This first monomer is equivalent to compound (a2) above.

The content of the constituent units derived from the first monomer is preferably 10-40 mass %, more preferably 15-35 mass %, and even more preferably 18-30 mass %, based on component (A), from the viewpoint of excellent developability and resolution.

The content of the constituent units derived from the first monomer is preferably such that the acid value of the component (A) or the acid value of the photosensitive resin composition is within the above range.

Second Monomer The second monomer is a non-acidic compound having at least one free-radically polymerizable ethylenically unsaturated bond in its molecule. Specifically, the second monomer may be the aforementioned compound (a3), or a compound other than compounds (a1) through (a3). These compounds have at least one free-radically polymerizable ethylenically unsaturated bond in their molecule.

Synthesis of Component (A) Component (A) can be synthesized by mixing one or more of the monomers described above with appropriate amounts of benzoyl peroxide and a free radical polymerization initiator such as azoisobutyronitrile in a solution diluted with a solvent such as acetone, methyl ethyl ketone, or isopropyl alcohol, followed by heating and stirring. Component (A) can also be synthesized by dropwise adding a portion of the mixture to the reaction solution. Alternatively, further solvent may be added after the reaction to adjust the desired concentration. Synthesis methods include solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization. Synthesis by living free radical polymerization is also possible.

<Component (B): Photopolymerizable Compound> Component (B) is a photopolymerizable compound, for example, a compound having at least one or two ethylenically unsaturated bonds in one molecule.

From the perspective of obtaining a photosensitive resin layer with moderate flexibility, the compound having ethylenically unsaturated bonds in the photosensitive resin composition is preferably a compound having two ethylenically unsaturated bonds per molecule. Furthermore, from the perspective of excellent crosslinking efficiency during the exposure step, the photosensitive resin composition may further contain a compound having three, four, five, or six ethylenically unsaturated bonds per molecule, in addition to or in addition to a compound having two ethylenically unsaturated bonds per molecule.

From the perspective of achieving excellent resolution, the content of the compound having two ethylenically unsaturated bonds per molecule is preferably 50% by mass or greater, more preferably 60% by mass or greater, and even more preferably 70% by mass or greater, based on the total amount of component (B). This content may be 100% by mass or less, based on the total amount of component (B).

When component (B) contains a compound having three or more ethylenically unsaturated bonds per molecule, the content of such compound is preferably 30% by mass or less, or 20% by mass or less, based on the total amount of component (B), from the perspective of improving crosslinking efficiency during the exposure step and thereby improving adhesion. Such content may be 1% by mass or more, or 5% by mass or more, based on the total amount of component (B).

Component (B) preferably comprises a (meth)acrylate compound. Regarding component (B), "a (meth)acrylate compound having n (meth)acryloyl groups in one molecule" may be referred to as "n-functional." For example, component (B) having one, two, three, four, five, or six ethylenically unsaturated bonds in one molecule may be referred to as "monofunctional (or monofunctional)," "difunctional," "trifunctional," "tetrafunctional," "pentafunctional," or "hexafunctional," respectively.

Examples of the bifunctional (meth)acrylate compound include alkyl di(meth)acrylate, 1,3-bis(meth)acryloyloxy-2-propanol, and tricyclodecanol di(meth)acrylate.

Examples of bifunctional (meth)acrylate compounds include polyalkylene glycol di(meth)acrylate and di(meth)acrylate having a bisphenol A structure. Here, "bisphenol A structure" includes a hydrogenated bisphenol A structure.

Examples of the polyalkylene glycol di(meth)acrylate include polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, and compounds represented by the following general formula (I). [Chemical 1] (In the formula, R ¹ is independently a hydrogen atom or a methyl group; X ¹ O and Y ¹ O are independently an oxyethyl group or an oxypropyl group; (X ¹ O)m1, (X ¹ O)m2, and (Y ¹ O)n1 are independently a (poly)oxyethylene chain or a (poly)oxypropylene chain; m1, m2, and n1 are independently an integer from 0 to 40; m1+m2 is 1 to 40; and n1 is 1 to 20).

Examples of the polyalkylene glycol di(meth)acrylate represented by the above formula (I) include a vinyl compound (product name "FA-024M" manufactured by Resonac) in which R ¹ = methyl, m1 + m2 = 6 (average value), n1 = 12 (average value), X ¹ O is an oxyethyl group, and Y ¹ O is an oxypropyl group.

Examples of di(meth)acrylates having a bisphenol A structure include compounds represented by the following general formula (II). [Chemistry 2] (In the formula, R ² is independently a hydrogen atom or a methyl group; X ² O and Y ² O are independently oxyethyl or oxypropyl; m3, m4, n2, and n3 are independently integers from 0 to 40; m3 + m4 is 1 to 40; and n2 + n3 is 0 to 20.) Furthermore, the di(meth)acrylate having a hydrogenated bisphenol A structure is a compound obtained by hydrogenating the aromatic ring of the compound represented by formula (II).

Examples of the compound represented by the above formula (II) include BPE-200 (R ² = methyl, X ² O = oxyethylidene, m3 + m4 = 4, and n2 = n3 = 0), BPE-500 (R ² = methyl, X ² O = oxyethylidene, m3 + m4 = 10, and n2 = n3 = 0), BPE-900 (R ² = methyl, X ² O = oxyethylidene, m3 + m4 = 17, and n2 = n3 = 0) (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), FA-321M (R ² = methyl, X ² O = oxyethylidene, m3 + m4 = 10, and n2 = n3 = 0), FA-P321M (R ² = methyl, X ² O=oxypropyl, m3+m4=10, and n2=n3=0) (the above are product names manufactured by Lisenoco Co., Ltd.)

From the perspective of excellent adhesion and resolution, component (B) preferably comprises a compound represented by the aforementioned general formula (II). The content of this compound, based on the total amount of component (B), is preferably 1% by mass or greater, more preferably 20% by mass or greater, even more preferably 50% by mass or greater, and even more preferably 70% by mass or greater. This content, based on the total amount of component (B), may be 100% by mass or less.

The average value of n2+n3+m3+m4 in the compound represented by formula (II) is preferably 20 or less, and more preferably 10 or less, from the perspective of excellent resolution and adhesion. Component (B) more preferably comprises a compound having an average value of n2+n3+m3+m4 of greater than 5 and less than 10, and a compound having an average value of n2+n3+m3+m4 of 5 or less. The average value of n2+n3+m3+m4 may be 2 or greater. The number of oxyethyl or oxypropyl group constituent units is an integer value in a single molecule and a rational number representing an average value in a collection of multiple molecules.

Commercially available bifunctional (meth)acrylate compounds include: NK ESTER (registered trademark) A-HD-N, NK ESTER A-NOD-N, NK ESTER A-DOD-N, NK ESTER A-NPG, NK ESTER 701A, NK ESTER A-200, NK ESTER A-400, NK ESTER A-600, NK ESTER A-1000, NK ESTER APG-200, NK ESTER APG-400, NK ESTER APG-700, NK ESTER A-PTMG65, NK ESTER A-DCP, NK ESTER ABE-300, NK ESTER A-BPE-4, NK ESTER A-BPE-10, NK ESTER A-BPE-20, NK ESTER HD-N, NK ESTER NOD-N, NK ESTER DOD-N, NK ESTER NPG, NK ESTER 701, NK ESTER 2G, NK ESTER 3G, NK ESTER 4G, NK ESTER 9G, NK ESTER 14G, NK ESTER 23G, NK ESTER 9PG, NK ESTER DCP, NK ESTER BPE-80N, NK ESTER BPE-100, NK ESTER BPE-200, NK ESTER BPE-500, NK ESTER BPE-900, NK ESTER BPE-1300N, NK OLIGO (registered trademark) UA-4200, NK OLIGO UA-160TM, NK OLIGO UA-290TM, NK OLIGO UA-W2A, NK OLIGO UA-4400, NK OLIGO UA-122P, NK OLIGO U-200PA (all manufactured by Shin-Nakamura Chemical Industry Co., Ltd.); LIGHT ACRYLATE (registered trademark) 3EG-A, LIGHT ACRYLATE 4EG-A, LIGHT ACRYLATE 9EG-A, LIGHT ACRYLATE 14EG-A, LIGHT ACRYLATE PTMGA-250, LIGHT ACRYLATE NP-A, LIGHT ACRYLATE MPD-A, LIGHT ACRYLATE 1.6HX-A, LIGHT ACRYLATE 1.9ND-A, LIGHT ACRYLATE DCP-A, LIGHT ACRYLATE BP-4EAL, LIGHT ACRYLATE BP-4PA, LIGHT ACRYLATE HPP-A, LIGHT ESTER G-201P (all manufactured by Kyoeisha Chemical Co., Ltd.); FANCRYL (registered trademark) FA-124AS, FANCRYL FA-023M, FANCRYL FA-121M, FANCRYL FA-124M, FANCRYL FA-125M, FANCRYL FA-129AS, FANCRYL FA-137M, FANCRYL FA-220M, FANCRYL FA-222A, FANCRYL FA-240A, FANCRYL FA-240M, FANCRYL FA-320M, FANCRYL FA-3218M, FANCRYL FA-321A, FANCRYL FA-321M, FANCRYL FA-324A, FANCRYL FA-731A, FANCRYL FA-P240A, FANCRYL FA-P270A, FANCRYL FA-PTG9A, FANCRYL FA-PTG9M, FANCRYL FA-PTG28A, FANCRYL FA-PTG49A (all manufactured by Lisenoko); DPGDA, HDDA, TPGDA, EBECRYL 145, EBECRYL 150, PEG400DA, EBECRYL 11, IRR 214-K, EBECRYL 130, EBECRYL PEG200DMA (all manufactured by DAICEL-ALLNEX); SR212, SR213, SR230, SR238F, SR259, SR268, SR272, SR306H, SR344, SR349, SR508, CD560, CD561, CD564, SR601, SR602, SR610, SR833S, SR9003 , SR9045, SR9209, SR205, SR206, SR209, SR210, SR214, SR231, SR239, SR248, SR252, SR297, SR348, SR480, CD540, CD541, CD542, SR603, SR644, SR9036 (all manufactured by Arkema); KAYARAD (registered trademark) NPGDA, KAYARAD PEG400DA, KAYARAD FM-400, KAYARAD R-167, KAYARAD HX-220, KAYARAD HX-620, KAYARAD R-551, KAYARAD R-712, KAYARAD R-604, KAYARAD R-684 (all manufactured by Nippon Kayaku Co., Ltd.), etc.

Examples of trifunctional or higher-functional (meth)acrylate compounds include trihydroxymethylpropane tri(meth)acrylate, glyceryl tri(meth)acrylate, isocyanuric acid tri(meth)acrylate, pentaerythritol (tri/tetra) (meth)acrylate, diglyceryl tetra(meth)acrylate, triglyceryl penta(meth)acrylate, ditrihydroxymethylpropane (tetra/penta/hexa) (meth)acrylate, and dipentaerythritol (tetra/penta/hexa) (meth)acrylate.

Examples of trifunctional or higher-functional (meth)acrylate compounds include compounds obtained by forming (meth)acrylates from an alcohol having three or more groups to which oxyalkylene groups can be added as a central skeleton, to which oxyalkylene groups such as oxyethyl, oxypropyl or oxybutyl are added, and (meth)acrylic acid. Examples of such compounds include epoxy-modified tri(meth)acrylate of trihydroxymethylpropane, epoxy-modified tri(meth)acrylate of glycerol, epoxy-modified pentaerythritol (tri/tetra)(meth)acrylate, epoxy-modified diglyceryl tetra(meth)acrylate, epoxy-modified triglyceryl penta(meth)acrylate, epoxy-modified ditrihydroxymethylpropane (tetra/penta/hexa)(meth)acrylate, epoxy-modified dipentaerythritol (tetra/penta/hexa)(meth)acrylate, and epoxy-modified isocyanuric acid tri(meth)acrylate. Preferred oxyalkylene groups include ethylene oxide, propylene oxide, and butylene oxide.

From the viewpoint of excellent developing properties, the trifunctional or higher-functional (meth)acrylate compound may include epoxide-modified pentaerythritol (tri/tetra) (meth)acrylate and/or epoxide-modified dipentaerythritol (tetra/penta/hexa) (meth)acrylate.

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

The content of component (B) relative to the total solid content of the photosensitive resin composition is preferably 30% by mass or greater, more preferably 35% by mass or greater, to ensure excellent sensitivity, viscosity, and tracking properties. Furthermore, to ensure excellent edge melting resistance, viscosity, and resolution, it is preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 42% by mass or less. "Edge melting resistance" refers to the property of photoresist overflowing from the end faces of a photosensitive element roll during storage; the less this overflow, the better. Furthermore, "viscosity" refers to the adhesive properties of the photosensitive resin composition.

From the perspective of achieving excellent edge melting resistance, viscosity, and resolution, the ratio of the content of component (B) to the content of component (A) based on the total solid content of the photosensitive resin composition {(content of component (B) / content of component (A))} is preferably 1.2 or less, more preferably 1.1 or less, even more preferably 1.0 or less, and particularly preferably 0.9 or less. Furthermore, this ratio is preferably 0.5 or greater, more preferably 0.55 or greater, and particularly preferably 0.6 or greater.

The amount of ethylenically unsaturated bonds per 100g of the solid content of the photosensitive resin composition is preferably 0.1 to 0.3 mol. When this amount is 0.1 mol or greater, the water washing step after development can be performed, thereby preventing the photosensitive resin component from eluting from the cured photoresist pattern during the washing step, thereby preventing contamination of the washing step. Furthermore, when this amount is 0.3 mol or less, the water washing step after development can be performed, thereby preventing damage and detachment of the cured photoresist pattern during the washing step, thereby preventing contamination of the washing step. From the same viewpoint, the amount is more preferably 0.1 to 0.25 mol, further more preferably 0.1 to 0.2 mol, particularly preferably 0.11 to 0.2 mol or 0.11 to 0.15 mol.

The amount of ethylenically unsaturated bonds per 100 g of the solid content of the photosensitive resin composition is preferably 0.1 mol or more, more preferably 0.11 mol or more, even more preferably 0.12 mol or more, and particularly preferably 0.13 mol or more. Furthermore, this amount is preferably 0.3 mol or less, more preferably 0.28 mol or less, even more preferably 0.25 mol or less, and particularly preferably 0.22 mol or less, 0.20 mol or less, 0.18 mol or less, or 0.15 mol or less.

Component (C): Photopolymerization Initiator Component (C) is a compound that generates free radicals upon exposure to light (active radiation), which then promotes the free radical polymerization of component (B).

Examples of the component (C) include hexaarylbiimidazole compounds, N-aryl-α-amino acid compounds, quinone compounds, aromatic ketone compounds, anthracene or anthracene derivatives, acetophenone compounds, acylphosphine oxide compounds, benzoin compounds, benzoin ether compounds, dialkyl ketal compounds, thioxanthone compounds, dialkylaminobenzoate compounds, oxime ester compounds, acridine compounds, pyrazoline derivatives, N-arylamino acid ester compounds, and halogen compounds.

The content of component (C) is preferably 0.1-20% by mass, more preferably 0.5-10% by mass, relative to the total solid content of the photosensitive resin composition. By adjusting the content of component (C) within this range, sufficient sensitivity is easily achieved, allowing light to penetrate sufficiently to the bottom of the photosensitive resin layer even with a small exposure dose, thereby easily achieving high resolution.

From the perspectives of excellent sensitivity, resolution, and adhesion, component (C) preferably contains a hexaarylbiimidazole compound. In this case, from the same perspective, the content of the hexaarylbiimidazole compound in the photosensitive resin composition is preferably 0.1 to 15% by mass, more preferably 0.5 to 10% by mass.

Component (C) preferably contains a hexaarylbiimidazole compound and a photopolymerization initiator other than the hexaarylbiimidazole compound (e.g., an aromatic ketone compound). In this case, the content of the photopolymerization initiator other than the hexaarylbiimidazole compound in the photosensitive resin composition is preferably 0.5% by mass or less, more preferably 0.01 to 0.4% by mass. Furthermore, the content of the hexaarylbiimidazole compound in the photosensitive resin composition is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass.

Examples of hexaarylbiimidazole compounds include dimers of compounds having a porphyrin structure (porphyrin dimers), namely, dimers of 2,4,5-triarylimidazoles. Examples of 2,4,5-triarylimidazole dimers include dimers of 2-(o-chlorophenyl)-4,5-diphenylimidazole (also known as 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole), 2,2'-bis-(2-fluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole, and 2,2'-bis-(2,3-difluoromethylphenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole. azole, 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, 2,2'-bis-(2,3,4-trifluorophenyl)-4,4',5,5'-tetrakis-(3-methoxyphenyl)-biimidazole Bis(2,3,6-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, 2,2'-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. Among these hexaarylbiimidazole compounds, the dimer of 2-(o-chlorophenyl)-4,5-diphenylimidazole is preferred due to its excellent sensitivity, resolution, and adhesion.

Examples of N-aryl-α-amino acid compounds include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine. Among these, N-phenylglycine is the most preferred N-aryl-α-amino acid compound due to its excellent sensitization effect.

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

Examples of aromatic ketone compounds include phenyl ketone, Michelle's ketone [4,4'-bis(dimethylamino)phenyl ketone], 4,4'-bis(diethylamino)phenyl ketone, and 4-methoxy-4'-dimethylaminophenyl ketone.

Examples of anthracene or anthracene derivatives include anthracene, 9,10-dialkoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, and 10-phenyl-9-anthracene boronic acid. Among these, anthracene or anthracene derivatives, 9,10-dibutoxyanthracene, 9,10-diphenylanthracene, and 10-phenyl-9-anthracene boronic acid are preferred due to their excellent sensitization effect and adhesion. 9,10-diphenylanthracene is particularly preferred.

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

Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzyldiphenylphosphine oxide, bis(2,4,6-trimethylbenzyl)phosphine oxide, and bis(2,6-dimethoxybenzyl)-2,4,4-trimethylpentylphosphine oxide. Commercially available acylphosphine oxide compounds include Lucirin TPO (manufactured by BASF) and Irgacure-819 (manufactured by BASF).

Examples of benzoin compounds and benzoin ether compounds include benzoin, benzoin ethyl ether, benzoin phenyl ether, methylbenzoin, and ethylbenzoin. Examples of dialkyl ketal compounds include dibenzodione dimethyl ketal and dibenzodione diethyl ketal. Examples of thiothione compounds include 2,4-diethylthiothione, 2,4-diisopropylthiothione, and 2-chlorothiothione. Examples of dialkylaminobenzoic acid ester compounds include ethyl dimethylaminobenzoate, ethyl diethylaminobenzoate, ethyl p-dimethylaminobenzoate, and 2-ethylhexyl-4-(dimethylamino)benzoate.

Examples of oxime ester compounds include 1-phenyl-1,2-propanedione-2-O-benzoyl oxime and 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. Commercially available oxime ester compounds include CGI-325, Irgacure-OXE01, and Irgacure-OXE02 (all manufactured by BASF).

As acridine compounds, 1,7-bis(9,9'-acridinyl)heptane or 9-phenylacridine are preferred due to their excellent sensitivity, resolution, and availability. As pyrazoline derivatives, 1-phenyl-3-(4-tert-butyl-phenyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-octyl-phenyl)-pyrazoline, and 1-phenyl-3-(4-methoxyphenyl-styryl)-5-(4-methoxyphenyl)-pyrazoline are preferred due to their excellent adhesion and ease of forming highly rectangular resist patterns.

Examples of N-aryl amino acid ester compounds include methyl N-phenylglycine, ethyl N-phenylglycine, n-propyl N-phenylglycine, isopropyl N-phenylglycine, 1-butyl N-phenylglycine, 2-butyl N-phenylglycine, tertiary butyl N-phenylglycine, pentyl N-phenylglycine, hexyl N-phenylglycine, pentyl N-phenylglycine, and octyl N-phenylglycine.

Examples of halogen compounds include bromopentane, isopentane bromopentane, 1,2-dibromo-2-methylpropane, 1,2-dibromoethane, diphenylmethane bromomethane, benzyl bromide, dibromomethane, tribromomethylphenylsulfonium, carbon tetrabromide, tris(2,3-dibromopropyl)phosphate, trichloroacetamide, iodopentane, isobutane iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, triazine chloride compounds, and diallyliodonium compounds. Among these, tribromomethylphenylsulfonium is preferred.

<Component (D): Dye> Component (D) includes dyes such as stealth dyes and primer dyes. The "dye" here refers to dyes that are soluble in water or organic solvents, as opposed to "pigments," which are poorly soluble in water or organic solvents or do not require water or organic solvents. Such pigments are often contained in photosensitive resin compositions for color filters as colorants, for example.

By incorporating a stealth dye as component (D), the photosensitive resin laminate exhibits excellent color development in the unexposed areas and resist pattern stripping properties. Examples of stealth dyes include stealth crystal violet (tris[4-(dimethylamino)phenyl]methane) and 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide. Of these, stealth crystal violet is particularly preferred.

The content of the stealth dye is preferably 0.01-2% by mass, more preferably 0.1-1.5% by mass, relative to the total solid content of the photosensitive resin composition. By adjusting the stealth dye content within this range, good color rendering and excellent sensitivity can be easily achieved.

Examples of base dyes include diamond green [CAS number (hereinafter the same): 633-03-4] (e.g., Aizen Diamond Green GH, manufactured by Hodogaya Chemical Industry Co., Ltd.), fuchsine [632-99-5], methyl violet [603-47-4], methyl green [82-94-0], Victoria Blue B [2580-56-5], basic blue 7 [2390-60-5] (e.g., Aizen Victoria Pure Blue BOH, manufactured by Hodogaya Chemical Industry Co., Ltd.), rose red B [81-88-9], rose red 6G [989-38-8], and basic yellow 2 [2465-27-2]. Of these, diamond green is preferred as a base dye due to its excellent coloring properties, hue stability, and exposure contrast.

The content of the primer dye relative to the total solid content of the photosensitive resin composition is preferably 0.001-3% by mass, more preferably 0.01-2% by mass, and even more preferably 0.04-1% by mass. To achieve good coloring properties, the primer dye content is preferably above the lower limit stated above. To maintain the sensitivity of the photosensitive resin layer, it is preferably below the upper limit stated above.

(E) Components: Other Ingredients The photosensitive resin composition may contain antioxidants, stabilizers, sensitizers, plasticizers, etc. as desired. Other ingredients are those other than (A) through (D) above.

Examples of antioxidants include triphenyl phosphite (e.g., ADEKA, trade name: TPP), tris(2,4-di-tert-butylphenyl) phosphite (e.g., ADEKA, trade name: 2112), tris(mononylphenyl) phosphite (e.g., ADEKA, trade name: 1178), and bis(mononylphenyl)-dinonylphenyl phosphite (e.g., ADEKA, trade name: 329K). These can be used alone or in combination.

The antioxidant content in the photosensitive resin composition is preferably 0.01-0.8% by mass, more preferably 0.01-0.3% by mass. To ensure good color stability of the resist pattern and enhance the sensitivity of the photosensitive resin layer, the antioxidant content is preferably above the lower limit. On the other hand, to achieve good color stability and enhanced adhesion while suppressing the color development of the resist pattern, the antioxidant content is preferably below the upper limit.

To improve the thermal stability and/or storage stability of the photosensitive resin composition, a stabilizer may be used. Examples of such stabilizers include at least one of a free radical polymerization inhibitor and an epoxy compound having a glycidyl group. These stabilizers may be used alone or in combination of two or more.

Examples of free radical polymerization inhibitors include p-methoxyphenol, hydroquinone, oligol, naphthylamine, phenothiazine, tertiary butyl o-catechol, cuprous chloride, 2,6-di-tertiary butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tertiary butylphenol), 2,2'-methylenebis(4-ethyl-6-tertiary butylphenol), triethylene glycol-bis[3-(3-tertiary butyl-5-methyl-4-hydroxyphenyl)propionate], aluminum salts of nitrosophenylhydroxylamine (e.g., aluminum salts of nitrosophenylhydroxylamine with a 3 mol addition), and diphenylnitrosamine. Among these, triethylene glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], phenothiazine, tert-butyl o-catechin, and/or an aluminum salt of nitrosophenylhydroxylamine added with 3 mol. These can be used alone or in combination of two or more.

Examples of epoxy compounds having a glycidyl group include neopentyl glycol diglycidyl ether (e.g., Epolight 1500NP manufactured by Kyoeisha Chemical Co., Ltd.), nonaethylene glycol diglycidyl ether (e.g., Epolight 400E manufactured by Kyoeisha Chemical Co., Ltd.), bisphenol A-propylene oxide 2-mole adduct diglycidyl ether (e.g., Epolight 3002 manufactured by Kyoeisha Chemical Co., Ltd.), and 1,6-hexanediol diglycidyl ether (e.g., Epolight 1600 manufactured by Kyoeisha Chemical Co., Ltd.). These can be used alone or in combination of two or more.

The combined content of the free radical polymerization inhibitor and the glycidyl group-containing epoxy compound in the photosensitive resin composition is preferably 0.001 to 3% by mass, more preferably 0.05 to 1% by mass. To impart good storage stability to the photosensitive resin composition, the combined content is preferably at least the above lower limit. To maintain the sensitivity of the photosensitive resin layer, the combined content is preferably at most the above upper limit.

[Protective Film] The photosensitive resin laminate of this embodiment can further include a protective film. A temporary support, a photosensitive resin layer, and a protective film can be sequentially laminated. The protective film can be laminated onto the photosensitive resin layer side of the laminate comprising the temporary support and the photosensitive resin layer, and functions as a protective layer for protecting the photosensitive resin layer.

When the adhesion between the photosensitive resin layer and the protective film is sufficiently weaker than the adhesion between the photosensitive resin layer and the temporary support, the protective film can be easily peeled from the photosensitive resin layer. Examples of protective films include polyethylene film, polypropylene film, stretched polypropylene film, and polyester film. A release layer may also be provided on the surface of the protective film.

The thickness of the protective film is preferably 10 to 100 μm, more preferably 10 to 50 μm. Examples of protective films include: ALPHAN (registered trademark) EM-501, ALPHAN E-200, ALPHAN E-201F, ALPHAN FG-201, ALPHAN MA-411 (all manufactured by Prince Airt Co., Ltd.); TORAYFAN (registered trademark) KW37, TORAYFAN 2578, TORAYFAN 2548, TORAYFAN 2500, TORAYFAN YM17S, Cerapeel (registered trademark) PJ271, Cerapeel PJ111, Cerapeel HP2, Cerapeel PJ101, Cerapeel WZ, Cerapeel MDA, Cerapeel MFA, Cerapeel TK07, Cerapeel BKE, Cerapeel BX8A, Cerapeel SY (all manufactured by Toray Industries, Inc.); GF-18, GF-818, GF-858 (all manufactured by Tamapolly), etc.

[Photosensitive Resin Laminate Roll] Another aspect of this embodiment is a photosensitive resin laminate roll, which is formed by rolling up the above-described photosensitive resin laminate. The photosensitive resin laminate forming the roll may be elongated or may have a core at the center of the roll.

[Photoresist Pattern Formation Method] Another aspect of this embodiment is a method (manufacturing method) for forming a photoresist pattern using the above-mentioned photosensitive resin laminate. This manufacturing method comprises the following steps: Laminating a photosensitive resin layer from the above-mentioned photosensitive resin laminate on a substrate (lamination step); Exposing the photosensitive resin layer (exposure step); and Developing the exposed photosensitive resin layer. By undergoing these steps, a photoresist pattern is produced.

(Lamination Step) In the lamination step, the photosensitive resin layer of the aforementioned photosensitive resin laminate is deposited on a substrate. Specifically, if the photosensitive resin laminate includes a protective film, the protective film is peeled off from the photosensitive resin laminate to expose the photosensitive resin layer. The photosensitive resin layer is then heated and pressed onto the substrate surface using a lamination press, performing one or more lamination steps. Examples of substrate materials include copper, stainless steel (SUS), glass, and indium tin oxide (ITO). The heating temperature during lamination is generally between 40°C and 160°C. Heating and laminating can be performed using a lamination press equipped with rollers or by repeatedly passing the laminate of the substrate and photosensitive resin layer through the rollers several times. Heating and laminating can be performed in a reduced pressure environment if desired.

(Exposure Step) The exposure step involves exposing the photosensitive resin layer. Specifically, an exposure machine is used to expose the photosensitive resin layer. Exposure can be performed after removing a temporary support member, if desired. During the exposure step, the exposure is performed through a photomask. The exposure amount can be determined by the light source illumination and exposure time, or can be measured using a light meter.

During the exposure step, direct imaging exposure can also be performed. In direct imaging exposure, the photosensitive resin layer is exposed directly using a patterning device, without a mask. The light source used is a semiconductor laser with a wavelength of 350-410nm or an ultra-high-pressure mercury lamp. When the pattern is computer-controlled, the exposure dose is determined by the illumination of the exposure light source and the substrate's travel speed.

In the exposure step, the exposure light irradiation method is preferably at least one method selected from the group consisting of projection exposure method, proximity exposure method, contact exposure method, direct imaging exposure method, and electron beam direct writing method, and more preferably projection exposure method or direct imaging exposure method.

The exposure step may also include: After the exposure and before the development step, heating the substrate and the exposed photosensitive resin layer (heating step). In this heating step, the heating temperature is preferably between approximately 30°C and approximately 200°C, more preferably between 30°C and 150°C, and even more preferably between 35°C and 120°C. Implementing the heating step facilitates achieving excellent resolution and adhesion. Heating can also be performed using an infrared or far-infrared heating furnace, hot air, a constant temperature bath, a heating plate, a hot air dryer, an infrared dryer, or a heating roller.

The time elapsed from the exposure step to the heating step, more specifically, the time from the moment exposure is completed (i.e., the moment exposure stops) to the moment heating starts, is preferably 10 to 600 seconds, more preferably 20 to 300 seconds. The time elapsed from the moment heating starts to the moment heating stops is preferably 1 to 120 seconds, more preferably 5 to 60 seconds.

(Developing Step) The developing step involves developing the exposed photosensitive resin layer. Specifically, a developing device is used to remove the unexposed or exposed areas of the exposed photosensitive resin layer using a developer. Subsequently, a developer containing or composed of an alkaline aqueous solution is used to remove the unexposed or exposed areas, thereby forming a photoresist pattern. If a temporary support is present on the photosensitive resin layer after exposure, it is removed from the layer before the above-described development process is performed.

Alkaline aqueous solutions used as developer solutions are preferably aqueous solutions _{of Na₂CO₃} , _K₂CO₃ , and tetramethylammonium hydroxide. _The alkaline aqueous solution is selected based on the properties of the photosensitive resin layer; for example, a _{Na₂CO₃ aqueous} solution with a concentration of 0.2-2% by mass is used. The developer solution may also contain a surfactant and/or a defoaming agent, or a small amount of an organic solvent to promote development. During the development step, the developer solution temperature is preferably maintained constant within the range of 20-40°C.

The developing step preferably includes, after development, a step of washing the substrate and photoresist pattern (washing step). The washing step facilitates removal of developer residues on the substrate and photoresist pattern. Examples of the washing water used in the washing step include pure water and industrial water. To achieve excellent resolution and easily form a highly rectangular photoresist pattern, a polyvalent metal salt at a concentration of 0.001 to 1 mass% may be mixed into the washing water to suit the characteristics of the photosensitive resin layer. Examples of polyvalent metal salts include _MgSO₄ . The temperature of the washing water in the washing step is preferably maintained constant within the range of 20 to 40°C.

The development step, after the development step, or after the development step and the water washing step, may also include: Heating the substrate and the formed photoresist pattern (heating step). In this heating step, the heating temperature is preferably 60-300°C. This heating step can improve the chemical resistance of the photoresist pattern. Heating can be performed using an infrared or far-infrared heating furnace, hot air, or other methods.

[Conductor Pattern Manufacturing Method] Another aspect of this embodiment is a method for manufacturing a conductor pattern using the above-mentioned photosensitive resin laminate. This manufacturing method comprises the following steps: Laminating the photosensitive resin layer of the above-mentioned photosensitive resin laminate on a substrate; Exposing the photosensitive resin layer; and Forming a photoresist pattern by developing the exposed photosensitive resin layer; Etching or plating the substrate with the photoresist pattern (conductor pattern formation step).

In the conductor patterning step, the substrate with the photoresist pattern formed thereon is etched or plated. Specifically, the conductor patterning step involves forming a conductor pattern on the surface (e.g., copper surface) of the substrate (e.g., a metal plate or metal film insulation plate, as described above) exposed by development using conventional etching or plating methods.

The conductor pattern forming step, after forming the conductor pattern, may also include: A step of stripping the photoresist pattern remaining on the substrate from the substrate (a stripping step). By removing the photoresist pattern from the substrate through the stripping step, a wiring board (e.g., a printed circuit board) having the desired conductor pattern is obtained.

During the stripping step, an aqueous solution with a stronger alkalinity than the developer is used. Examples of such alkaline aqueous solutions (hereinafter referred to as "stripping solutions") include 2-5% by mass aqueous solutions of NaOH or KOH, or aqueous solutions of organic amines. The stripping solution may also contain a small amount of a water-soluble solvent, such as ethanol. The temperature of the stripping solution during the stripping step is preferably between 40°C and 70°C.

In this embodiment, the photosensitive resin laminate can be used in the following applications: the manufacture of printed wiring boards; the manufacture of lead frames for mounting IC chips; the precision processing of metal foils, such as metal mask manufacturing; the manufacture of packages, such as ball grid arrays (BGAs) and chip-scale packages (CSPs); the manufacture of tape substrates, such as chip-on-film (COF) and tape automated bonding (TAB); the manufacture of semiconductor bumps; and the manufacture of ITO electrodes, address electrodes, electromagnetic shielding covers, and other partitions for flat panel displays.

By performing the above-mentioned conductor pattern forming step, a method for manufacturing a wiring board according to another embodiment of the present invention can be provided. The wiring board has a conductor pattern formed by the above-mentioned conductor pattern forming step.

Unless otherwise specified, the values of the above parameters in this specification are determined according to the measurement methods described in the Examples below. [Examples]

The following examples and comparative examples illustrate this embodiment. However, this embodiment is not limited to the following examples. The following methods were used for various fabrication, measurements, and evaluations of the embodiments and comparative examples.

[Example 1] (Synthesis of Component (A)) As shown in the table below, the specified monomers (copolymer components) were mixed with azobisisobutyronitrile in the specified amounts (unit: parts by mass) to prepare solution (a)-1. A flask equipped with a stirrer, reflux condenser, thermometer, dropping funnel, and nitrogen inlet was charged with 140 g of methyl ethyl ketone and 40 g of ethanol. The flask was stirred while nitrogen was introduced and the temperature was raised to 80°C. Next, solution (a)-1 was added dropwise to the flask at a constant rate over 4 hours, followed by stirring at 80°C for 2 hours.

Next, 0.5 parts by mass of azobisisobutyronitrile was dissolved in 50 parts by mass of a mixture of 30 parts by mass of methyl ethyl ketone and 20 parts by mass of ethanol to prepare solution (b). 50.5 g of solution (b) was added dropwise to the flask at a constant rate over 10 minutes, followed by stirring at 80°C for 3 hours. The mixture in the flask was then heated to 90°C over 30 minutes, then maintained at 90°C with stirring for 2 hours. Stirring was then stopped and the mixture was cooled to room temperature (25°C). This yielded solutions of alkali-soluble polymers A1-A9. The weight-average molecular weights (Mw) of alkali-soluble polymers A1-A9 are shown in the table below.

The weight-average molecular weight is determined by gel permeation chromatography (GPC) and derived by conversion using a calibration curve based on standard polystyrene. The GPC conditions are as follows. (GPC Conditions) Pump: JASCO Corporation PU-4580 Degasser: DG-2080-53 Column Oven: CO-1560 Columns: 4 of the following Shodex Corporation KF-807 / KF-806M × 2 / KF-802.5 Eluent: Tetrahydrofuran Measurement Temperature: 40°C Flow Rate: 1.00 mL/min Detector: JASCO Corporation RI-1560

Preparation of the Photosensitive Resin Layer and Photosensitive Resin Laminate The ingredients listed in the table below were mixed according to the indicated amounts (parts by mass) and methyl ethyl ketone was added at a solids concentration of 60%. The mixture was thoroughly stirred to obtain a prepared solution of a photosensitive resin composition. The amounts (parts by mass) listed in the table below refer to the mass of the non-volatile components (solids).

A 16μm-thick polyethylene terephthalate film (QS71, manufactured by Toray Industries, Inc.) was prepared as a support film. The prepared solution was evenly applied to the support film using a bar coater and then dried in a dryer at 95°C for 2 minutes and 30 seconds. This resulted in a photosensitive resin laminate with a 25μm-thick photosensitive resin layer on the support film.

Next, a 19μm-thick polyethylene film (GF-818, manufactured by Tamaboli Co., Ltd.) was laminated to the surface of the photosensitive resin layer opposite the support film, acting as a protective film. The laminate of the support film, photosensitive resin layer, and protective film was referred to as the photosensitive resin laminate.

<Preparing a Photosensitive Resin Roll> The resulting photosensitive resin laminate is rolled up using conventional methods to produce a photosensitive resin roll.

<Entire Surface of Substrate> The surface of a 0.4 mm thick copper-clad laminate with an 18 μm thick rolled copper foil was cleaned with a 10 mass% H ₂ SO ₄ aqueous solution and then with pure water.

Lamination Step The cleaned copper-clad laminate was preheated to 50°C. While peeling the protective film from the photosensitive resin laminate, the laminate was laminated using a hot roll laminating press (AL-700, manufactured by Asahi Kasei Corporation) at a roll temperature of 105°C, with the photosensitive resin laminate in contact with the preheated copper-clad laminate surface. This produced an evaluation substrate. The air pressure during lamination was set at 0.35 MPa, and the lamination speed was set at 1.5 m/min.

Exposure Step After lamination for two hours, the evaluation substrate was exposed using a projection exposure machine (UX-2003SM-AGG01, manufactured by U-Zhi Wang Electric Co., Ltd.) at a wavelength of 365nm using a designated projection exposure mask pattern.

Heating Step After one minute of exposure, the evaluation substrates were heated for 30 seconds using a constant-temperature thermostat (DKM600, manufactured by Yamato Scientific Co., Ltd.) with air flow set to 60°C.

<Development Step> The support film is peeled from the photosensitive resin layer. Development is then performed using an alkaline developer (Fuji Kiko Co., Ltd., dry film developer) using a 1% by mass _{Na₂CO₃ aqueous} solution at 30°C at a pressure of 0.15 Pa for a specified time (development spraying step). The photosensitive resin layer is then rinsed by spraying pure water for a specified time (water washing spraying step). This forms a photoresist pattern on the evaluation substrate. The development spraying and water washing spraying times are each set to twice the minimum development time described below.

[Example 2] to [Example 24] and [Comparative Examples 1 to 6] Except for the changes shown in the table below, the (A) component, photosensitive resin layer, photosensitive resin laminate, and photosensitive resin roll were prepared in the same manner as in Example 1, and a photoresist pattern was formed.

[Evaluation] <Developability (Minimum Development Time: sec)> After the lamination step, the evaluation substrate was subjected to the above-described development step. The minimum time required for complete dissolution of the photosensitive resin layer was visually measured and used as the minimum development time. Using the measured minimum development time, the development performance was evaluated based on the following criteria. In this example, the shorter the minimum development time, the better the development performance. A minimum development time of 20 seconds or less was considered acceptable, and a minimum development time of 18 seconds or less was considered particularly good.

<Sensitivity (Optimum Exposure: mJ/ ^cm² )> Prepare a mask pattern with a line width (L)/space width (S) ratio (hereinafter simply referred to as "L/S") of 8/8 (unit: μm). Next, use this mask to perform the aforementioned exposure, heating, and development steps to form a pattern on an evaluation substrate. Next, determine the exposure (10 mJ/ ^cm² spacing) (unit: mJ/ ^cm² ) that gives the formed pattern a line width closest to 8 μm. The lower this exposure (optimum exposure), the higher the sensitivity. The line width of the pattern is measured based on an image observed using an optical microscope at 100x magnification.

Figure 1 is a plan view of an example of the configuration of a photomask pattern used in this evaluation. In the figure, within region 100 of the photomask, areas that transmit exposure light are designated by 10 (transmitting region 10), while areas that do not transmit exposure light are designated by 1 (light-blocking region 1). Light-blocking region 1 is indicated by diagonal lines. Transmitting region 10 has a predetermined width and extends in the x-direction. Multiple transmitting regions 10 are arranged at predetermined intervals in the width direction (y-direction). In this embodiment, the unexposed portions of the photosensitive resin layer are removed during the development step. Therefore, based on the mask pattern shown in the figure, it can be theoretically predicted that a photoresist pattern having an L/S ratio corresponding to the width of the transmissive region 10 (L: line) and the width of the light-shielding region 1 (S: space) will be formed.

Adhesion Evaluation was conducted using a photoresist pattern with an L/S ratio of x/3x {x = 1 to 15 (varied at 0.5 μm intervals)} (unit: μm). Specifically, the evaluation substrate, obtained after the aforementioned full-surface and lamination steps, was exposed through the photoresist at the optimal exposure dose. Subsequently, the substrate was subjected to the aforementioned heating and development steps to form a photoresist pattern with a line length of 7 mm.

Figure 2 is a plan view of an example of the mask pattern used in this evaluation. In the figure, region 100A of the mask includes a transparent region 10 and a light-blocking region 1. The L/S value in region 100A shown in the figure is different from that in region 100 shown in Figure 1.

Observe the formed photoresist pattern using an optical microscope at 100x magnification. Detect lines (exposed portions) in the observed image without snaking or defects. Use the minimum line width (L1) to evaluate adhesion based on the following criteria. In this embodiment, the smaller the minimum line width (L1), the better the adhesion. A minimum line width (L1) of 6.0 μm or less is considered acceptable, and a minimum line width (L1) of 5.0 μm or less is considered exceptionally good.

Resolution Evaluation was performed using a photomask with an L/S ratio of x/x (x = 1 to 20 (varied in 0.5 μm intervals)) (unit: μm). Specifically, the evaluation substrate, obtained after the aforementioned full-surface and lamination steps, was exposed through the photomask at the optimal exposure dose. Subsequently, through the aforementioned heating and development steps, a photoresist pattern with a line (exposed portion) length of 7 mm was formed.

Figure 3 is a plan view of an example of the configuration of the photomask pattern used in this evaluation. In the figure, region 100B of the photomask includes a transmissive region 10 and a light-shielding region 1. The light-shielding region 1 has a predetermined width and extends in the x-direction. Multiple light-shielding regions 1 are arranged at predetermined intervals in the width direction (y-direction). The photomask pattern in Figure 3, similar to the photomask pattern in Figure 1, theoretically predicts that a photoresist pattern with an L/S ratio corresponding to the width of the transmissive region 10 (L: line) and the width of the light-shielding region 1 (S: pitch) will be formed.

The formed photoresist pattern was observed using an optical microscope at 100x magnification. The lines in the observed image were detected to be free of meandering and defects (exposed portion) and free of photoresist residue (unexposed portion). The minimum line width (L2) was used to evaluate resolution based on the following criteria. In this embodiment, the smaller the minimum line width (L2), the better the resolution. A minimum line width (L2) of 7.0μm or less was considered acceptable, and a minimum line width (L2) of 6.0μm or less was considered exceptionally good.

Fine Line Strength Evaluation was conducted using a photoresist pattern with an L/S ratio of x/200 (x = 1 to 20 (varied in 0.5 μm intervals)) (unit: μm). Specifically, the evaluation substrate, obtained after the aforementioned full-surface and lamination steps, was exposed through the photoresist at the optimal exposure dose. Subsequently, through the aforementioned heating and development steps, a photoresist pattern with a line (exposed portion) length of 7 mm was formed.

Figure 4 is a plan view of an example of the mask pattern used in this evaluation. In the figure, region 100C of the mask shows a transparent region 10 and a light-blocking region 1. The L/S value in region 100C shown in the figure is different from that in region 100 shown in Figure 1.

Observe the formed photoresist pattern using an optical microscope at 100x magnification. Detect lines (exposed portions) in the observed image that are free of meandering and defects. Use the minimum line width (L3) to evaluate fine line strength based on the following criteria. In this embodiment, the smaller the minimum line width (L3), the better the fine line strength. A minimum line width (L3) of 7.0 μm or less is considered acceptable, and a minimum line width (L3) of 6.0 μm or less is considered exceptionally good.

The above results are shown in the table below. In addition, in each of the embodiments, it was confirmed that a wiring board having a conductive pattern can be manufactured using conventional methods.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

As demonstrated in the above table, the embodiments provide a photosensitive resin laminate that not only achieves excellent adhesion and resolution of the photoresist pattern, but also balances the developability of the photosensitive resin layer and the strength of the photoresist pattern, achieving all of these desired effects. [Industrial Applicability]

By using the photosensitive resin laminate of the present invention, a photosensitive resin laminate can be provided that not only achieves excellent adhesion and resolution of the photoresist pattern, but also balances the developability of the photosensitive resin layer and the strength of the photoresist pattern, thereby satisfying all these requirements. This photosensitive resin laminate can be widely used as a photosensitive resin laminate for forming photoresist patterns on printed wiring boards, etc.

1: Light-blocking area 10: Transmitting area 100: Area within the mask 100A: Area within the mask 100B: Area within the mask 100C: Area within the mask L: Line S: Spacing

[Figure 1] is a plan view showing the configuration of a photomask pattern related to this embodiment. [Figure 2] is a plan view showing the configuration of a photomask pattern related to this embodiment. [Figure 3] is a plan view showing the configuration of a photomask pattern related to this embodiment. [Figure 4] is a plan view showing the configuration of a photomask pattern related to this embodiment.

Claims (17)

A photosensitive resin laminate comprising a temporary support and a photosensitive resin layer containing a photosensitive resin composition; wherein the photosensitive resin composition comprises the following components: (A) an alkali-soluble polymer, (B) a photopolymerizable compound, and (C) a photopolymerization initiator; wherein the alkali-soluble polymer (A) comprises a copolymer (A-1) having the following constituent units: (a1) a constituent unit derived from a compound having two or more alcoholic hydroxyl groups and a (meth)acrylic group; and (a3) a constituent unit derived from styrene, a styrene derivative, or benzyl (meth)acrylate. The photosensitive resin laminate according to claim 1, wherein the (a1) constituent unit derived from the compound is glyceryl mono(meth)acrylate. The photosensitive resin laminate according to claim 1 or 2, wherein the content of the constituent unit (a1) in the component (A) is 0.5 to 30 mass %. The photosensitive resin laminate according to claim 1 or 2, wherein the content of the constituent unit (a1) in the component (A) is 1.0 to 10% by mass. The photosensitive resin laminate according to claim 1 or 2, wherein the content of the constituent unit (a1) in the component (A) is 1.0 to 5.0 mass %. The photosensitive resin laminate according to claim 1 or 2, wherein the copolymer (A-1) further comprises the following constituent units: (a2) constituent units derived from a compound having a carboxyl group and an ethylenically unsaturated bond. The photosensitive resin laminate according to claim 1 or 2, wherein the content of the (a3) constituent unit in the component (A) is 10% by mass or more. The photosensitive resin laminate according to claim 1 or 2, wherein the content of the (a3) constituent unit in the (A) component is 20 to 70 mass %. The photosensitive resin laminate according to claim 1 or 2, wherein the weight average molecular weight of the component (A) is 10,000 to 60,000. The photosensitive resin laminate according to claim 1 or 2, wherein the component (B) contains a compound having two ethylenically unsaturated bonds in one molecule. The photosensitive resin laminate according to claim 1 or 2, wherein the component (C) contains a hexaarylbiimidazole compound. The photosensitive resin laminate according to claim 1 or 2, wherein the total content of the component (A), the component (B), and the component (C) is 90% by mass or more relative to the total solid content of the photosensitive resin composition. The photosensitive resin laminate as claimed in claim 1 or 2, further comprising a protective film. A photosensitive resin laminate for forming a conductive pattern is composed of the photosensitive resin laminate as described in claim 1 or 2. A photosensitive resin laminate roll is formed by rolling up the photosensitive resin laminate according to claim 1 or 2. A method for forming a photoresist pattern comprises the following steps: Laying a photosensitive resin layer from the photosensitive resin laminate described in claim 1 or 2 on a substrate; Exposing the photosensitive resin layer; and Developing the exposed photosensitive resin layer to form a photoresist pattern. A method for manufacturing a wiring board having a conductive pattern comprises the following steps: Laying a photosensitive resin layer from the photosensitive resin laminate described in claim 1 or 2 on a substrate; Exposing the photosensitive resin layer; Forming a photoresist pattern by developing the exposed photosensitive resin layer; and Etching or plating the substrate having the photoresist pattern formed thereon to form a conductive pattern on the substrate.