Photosensitive resin laminate

Abstract

To provide a photosensitive resin laminate which includes a support film, and a photosensitive resin layer stacked on the support film.SOLUTION: A photosensitive resin layer contains 30 mass% to 70 mass% of an alkali-soluble polymer, 20 mass% to 50 mass% of a compound having an ethylenic unsaturated double bond, and 0.01 mass% to 20 mass% of a photopolymerization initiator. The alkali-soluble polymer contains (meth)acrylate having an aromatic group as a copolymerization component, and has an acid equivalent of 350 or more. The compound having the ethylenic unsaturated double bond contains 50 mass% to 100 mass% of an acrylate monomer based on total mass, and has a double bond equivalent of 150 or more. A thickness of the photosensitive resin layer is 30 μm or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a photosensitive resin laminate. [Background technology]

[0002] Conventionally, photolithography has been used for the manufacture of printed wiring boards and precision processing of metals. Photosensitive resin laminates used in photolithography are classified into negative-type, in which unexposed areas are dissolved and removed, and positive-type, in which exposed areas are dissolved and removed.

[0003] A general method for forming a pattern using a photosensitive resin laminate will be briefly described. First, the protective layer is peeled off from the photosensitive resin laminate. Using a laminator, a photosensitive resin layer and a support are laminated on a substrate such as a copper-clad laminate or a copper-sputtered thin film in the order of substrate, photosensitive resin layer, and support. The photosensitive resin layer is exposed to light through a photomask bearing the desired wiring pattern. After exposure, the support is peeled off from the laminate, and the unexposed or exposed areas are dissolved or dispersed and removed using a developer, forming a resist pattern on the substrate. Bumps for semiconductors and the like can be formed by subjecting the substrate bearing the resist pattern to plating processes such as copper plating and solder plating.

[0004] Various photosensitive resin laminates have been studied for forming resist patterns or semiconductor bumps. For example, Patent Documents 1 to 7 describe photosensitive resin laminates having a photosensitive resin layer containing a specific alkali-soluble polymer, a photopolymerizable monomer, and a photopolymerization initiator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2009 / 078380 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-227309 [Patent Document 3] International Publication No. 2011 / 037182 [Patent Document 4] Japanese Patent Application Laid-Open No. 2013-246387 [Patent Document 5] Japanese Patent Application Laid-Open No. 2014-002285 [Patent Document 6] Japanese Patent Application Laid-Open No. 2014-126701 [Patent Document 7] International Publication No. 2019 / 088268 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, there has been a demand for finer and denser wiring, and accordingly, plating methods have become more widely used as a method for forming metal wiring. The shape of wiring formed by plating methods depends on the shape and thickness of the resist pattern. Plating methods generally use a photosensitive resin laminate having a thick photosensitive resin layer, and require high resolution and reduction of the phenomenon in which part of the photosensitive resin layer is not removed and remains in a tapered shape (so-called "footing").

[0007] If a photosensitive resin with poor processability in a stripper solution is used, the stripped cured resist does not dissolve and remains as a residue in the stripper solution. The retained stripping residue can clog the pump of the stripper. Therefore, the processability of the photosensitive resin in a stripper solution (hereinafter also referred to as "stripping processability") is required. Furthermore, the stripper solution used to remove the cured resist pattern consumes its components as it is removed. If a photosensitive resin with significant component consumption is used, problems such as stripping residue are likely to occur, reducing productivity, unless the stripper solution is made up more frequently. Therefore, it is required to reduce the frequency of stripper solution preparation (hereinafter also referred to as "stripper solution fatigue").

[0008] Photosensitive resins used in plating processes are also required to reduce the phenomenon in which plating penetrates into the bottom of a cured resist pattern during plating processing (hereinafter also referred to as "plating penetration").

[0009] Therefore, an object of the present disclosure is to provide a photosensitive resin laminate that can improve resolution, reduce footing, improve stripper processability and stripper fatigue resistance, and suppress plating penetration. [Means for solving the problem]

[0010] Examples of embodiments of the present disclosure are listed below. [1] A photosensitive resin laminate comprising a support film and a photosensitive resin layer laminated on the support film, wherein the photosensitive resin layer comprises: (A) 30% by mass to 70% by mass of an alkali-soluble polymer; (B) 20% by mass to 50% by mass of a compound having an ethylenically unsaturated double bond; (C) 0.01% by mass to 20% by mass of a photopolymerization initiator; Contains the alkali-soluble polymer contains a (meth)acrylate having an aromatic group as a copolymerization component and has an acid equivalent of 350 or more; the compound having an ethylenically unsaturated double bond contains 50% by mass to 100% by mass of an acrylate monomer based on the total mass of the compound having an ethylenically unsaturated double bond, and has a double bond equivalent of 150 or more; The photosensitive resin layer has a thickness of 30 μm or more. [2] Item 2. The photosensitive resin laminate according to item 1, wherein the alkali-soluble polymer contains benzyl (meth)acrylate as a copolymerization component. [3] When the film thickness of the photosensitive resin layer is T [μm] and the absorbance of the photosensitive resin layer at a wavelength of 365 nm is A, the following formula: [4] 4. The photosensitive resin laminate according to any one of items 1 to 3, wherein the alkali-soluble polymer contains 45% by mass to 95% by mass of benzyl (meth)acrylate as a copolymerization component. [5] ​5. The photosensitive resin laminate according to any one of items 1 to 4, wherein the alkali-soluble polymer contains 50% by mass or more of benzyl (meth)acrylate as a copolymerization component. [6] 5. The photosensitive resin laminate according to any one of items 1 to 4, wherein the alkali-soluble polymer contains 70% by mass or more of benzyl (meth)acrylate as a copolymerization component. [7] 7. The photosensitive resin laminate according to any one of items 1 to 6, wherein the compound having an ethylenically unsaturated double bond contains an acrylate monomer and a methacrylate monomer. [8] 8. The photosensitive resin laminate according to item 7, wherein the mass ratio of the acrylate monomer to the methacrylate monomer (acrylate monomer / methacrylate monomer) is 1.2 or more and 25.0 or less. [9] 9. The photosensitive resin laminate according to any one of items 1 to 8, wherein the alkali-soluble polymer does not contain styrene or a styrene derivative as a copolymerization component.

[10] 10. The photosensitive resin laminate according to any one of items 1 to 9, wherein the alkali-soluble polymer has an acid equivalent of 370 or more.

[11] 10. The photosensitive resin laminate according to any one of items 1 to 9, wherein the alkali-soluble polymer has an acid equivalent of 410 or more.

[12] 12. The photosensitive resin laminate according to any one of items 1 to 11, wherein the compound having an ethylenically unsaturated double bond does not include a compound having a trimethylolpropane skeleton.

[13] 13. The photosensitive resin laminate according to any one of items 1 to 12, wherein the compound having an ethylenically unsaturated double bond includes a tetrafunctional or higher functional compound.

[14] 14. The photosensitive resin laminate according to any one of items 1 to 13, wherein the compound having an ethylenically unsaturated double bond contains 50% by mass to 99% by mass of an acrylate monomer based on the total mass of the compound having an ethylenically unsaturated double bond.

[15] 14. The photosensitive resin laminate according to any one of items 1 to 13, wherein the compound having an ethylenically unsaturated double bond contains 60% by mass to 99% by mass of an acrylate monomer based on the total mass of the compound having an ethylenically unsaturated double bond.

[16] 14. The photosensitive resin laminate according to any one of items 1 to 13, wherein the compound having an ethylenically unsaturated double bond contains 70% by mass to 99% by mass of an acrylate monomer based on the total mass of the compound having an ethylenically unsaturated double bond.

[17] 17. The photosensitive resin laminate according to any one of items 1 to 16, wherein the compound having an ethylenically unsaturated double bond has a double bond equivalent of 200 or more.

[18] 18. The photosensitive resin laminate according to any one of items 1 to 17, wherein the mass ratio (A / B) of the alkali-soluble polymer to the compound having an ethylenically unsaturated double bond is 1.40 or more.

[19] 18. The photosensitive resin laminate according to any one of items 1 to 17, wherein the mass ratio (A / B) of the alkali-soluble polymer to the compound having an ethylenically unsaturated double bond is 1.60 or more.

[20] 18. The photosensitive resin laminate according to any one of items 1 to 17, wherein the mass ratio (A / B) of the alkali-soluble polymer to the compound having an ethylenically unsaturated double bond is 1.80 or more. [twenty one] 21. The photosensitive resin laminate according to any one of items 1 to 20, wherein the photopolymerization initiator contains a 2,4,5-triarylimidazole dimer. [twenty two] 22. The photosensitive resin laminate according to any one of items 1 to 21, wherein the photosensitive resin layer has a thickness of more than 40 μm. [twenty three] 22. The photosensitive resin laminate according to any one of items 1 to 21, wherein the photosensitive resin layer has a thickness of more than 70 μm. [twenty four] 22. The photosensitive resin laminate according to any one of items 1 to 21, wherein the photosensitive resin layer has a thickness of more than 100 μm. [twenty five] 22. The photosensitive resin laminate according to any one of items 1 to 21, wherein the photosensitive resin layer has a thickness of more than 150 μm.

[26] 22. The photosensitive resin laminate according to any one of items 1 to 21, wherein the photosensitive resin layer has a thickness of more than 200 μm. [Effects of the Invention]

[0011] According to the present disclosure, there is provided a photosensitive resin laminate that can improve resolution, reduce bottom shapes, improve stripper processability and stripper fatigue resistance, and suppress plating penetration. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a SEM photograph showing an example in which the resist edge (a) and plating penetration (b) are small. [Figure 2] FIG. 2 is a SEM photograph showing an example in which the resist edge (a) and plating penetration (b) are large. [Figure 3] FIG. 3 is an SEM photograph showing defects when a copper pillar is formed using a photosensitive resin with poor stripping solution fatigue resistance and then peeled off. DETAILED DESCRIPTION OF THE INVENTION

[0013] <Photosensitive resin laminate> The photosensitive resin laminate of the present disclosure includes a support film and a photosensitive resin layer laminated on the support film. The photosensitive resin laminate is preferably a dry film resist. The photosensitive resin layer may have a protective layer on the surface opposite to the support film, as necessary.

[0014] The photosensitive resin layer contains (A) 30% to 70% by mass of an alkali-soluble polymer, (B) 20% to 50% by mass of a compound having an ethylenically unsaturated double bond, and (C) 0.01% to 20% by mass of a photopolymerization initiator. If desired, the photosensitive resin layer may contain, in addition to components (A) to (C), a polymer other than component (A), a monomer other than component (B), an initiator other than component (C), and other components such as dyes, antioxidants, and plasticizers.

[0015] (A) Alkali-soluble polymer The alkali-soluble polymer contains a (meth)acrylate having an aromatic group as a copolymerization component. The amount of the alkali-soluble polymer is 30% by mass to 70% by mass, preferably 40% by mass to 70% by mass, and more preferably 50% by mass to 70% by mass, based on the total solid mass of the photosensitive resin layer. The inclusion of a (meth)acrylate having an aromatic group as a copolymerization component offers advantages such as a shorter minimum development time, improved resolution, reduced footing, and improved resistance to plating penetration. In this specification, the alkali-soluble polymer refers to a polymer that can be dissolved in an alkaline aqueous solution. (Meth)acrylate means acrylate or methacrylate, and (meth)acrylic means acrylic or methacrylic.

[0016] The aromatic group of the (meth)acrylate having an aromatic group is preferably an aromatic group having 6 to 20 carbon atoms, such as a phenyl group, a benzyl group, a biphenyl group, or a naphthyl group. The hydrogen atoms of the aromatic group may be unsubstituted or substituted. If substituted, the substituent may be a hydrocarbon group having 1 to 5 carbon atoms, a hydroxyl group, or a halogen group. From the viewpoints of shortening the minimum development time, improving resolution, reducing footing, and further improving resistance to plating penetration, the (meth)acrylate having an aromatic group preferably contains benzyl (meth)acrylate. The proportion of benzyl (meth)acrylate contained as a copolymerization component in the alkali-soluble polymer is preferably 45% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on the mass of all monomers constituting the alkali-soluble polymer. A high proportion of benzyl (meth)acrylate improves stripper processability. The amount of benzyl (meth)acrylate is preferably less than 100% by mass, more preferably 95% by mass or less, and even more preferably 90% by mass or less, based on the amount of all monomers constituting the alkali-soluble polymer.

[0017] The alkali-soluble polymer has an acid equivalent of 350 or more, preferably 370 or more, more preferably 380 or more, even more preferably 390 or more, even more preferably 400 or more, and particularly preferably 410 or more. The acid equivalent refers to the mass in grams of the alkali-soluble polymer per equivalent of carboxyl group. An acid equivalent of 350 or more has advantages such as shortening the minimum development time, improving resolution, and preventing fatigue of the stripper solution and wrinkles during storage. The upper limit of the acid equivalent is not limited, but is preferably 600 or less. An acid equivalent of 600 or less can improve developability and strippability.

[0018] The weight-average molecular weight of the alkali-soluble polymer is preferably 5,000 to 500,000, more preferably 5,000 to 300,000, even more preferably 10,000 to 200,000, and even more preferably 20,000 to 100,000. A weight-average molecular weight of 5,000 or more reduces development aggregates and improves the properties of the unexposed film in the photosensitive resin laminate, such as edge fusing and cut-chip resistance. On the other hand, a weight-average molecular weight of 500,000 or less improves solubility in the developer. Edge fusing is the property of preventing the photosensitive resin layer from protruding from the edge of a roll when the photosensitive resin laminate is wound into a roll. Cut-chip resistance is the property of preventing chipping when the unexposed film is cut with a cutter. If the cut chip property is poor, scattered chips may adhere to, for example, the upper surface of the photosensitive resin laminate, and the chips may be transferred to a mask in the subsequent exposure step, causing defects.

[0019] The alkali-soluble polymer may contain a copolymerization component other than the (meth)acrylate having an aromatic group. Examples of such copolymerization components include carboxylic acids, carboxylates, and acid anhydrides having at least one polymerizable unsaturated group in the molecule, such as (meth)acrylic acid, fumaric acid, cinnamic acid, crotonic acid, itaconic acid, maleic anhydride, maleic acid half ester (meth)acrylic acid, alkyl (meth)acrylates; (meth)acrylonitrile; (meth)acrylamide; and aromatic vinyl compounds such as styrene and styrene derivatives. Examples of styrene derivatives include oxystyrene, hydroxystyrene, acetoxystyrene, alkylstyrene, and halogenoalkylstyrene.

[0020] The alkyl group of the alkyl (meth)acrylate may be linear, branched, or cyclic, and may have, for example, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more, and 12 or less, 11 or less, 10 or less, 9 or less, or 8 or less carbon atoms. More specific examples of the alkyl group of the alkyl (meth)acrylate include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, ethylhexyl, nonyl, decyl, undecyl, and dodecyl groups. Among these, 2-ethylhexyl is even more preferred from the viewpoints of shortening development time and reducing footing of the resist pattern. By using, for example, 2-ethylhexyl (meth)acrylate as part of the monomer used in synthesizing the alkali-soluble polymer, an alkali-soluble polymer containing 2-ethylhexyl acrylate as a copolymerization component can be obtained.

[0021] Preferred combinations of copolymerization components in the alkali-soluble polymer include, for example, (meth)acrylic acid and benzyl (meth)acrylate; (meth)acrylic acid, benzyl (meth)acrylate and an aromatic vinyl compound; and (meth)acrylic acid, benzyl (meth)acrylate and an alkyl (meth)acrylate. More specific examples include, for example, methacrylic acid and benzyl methacrylate; acrylic acid, benzyl methacrylate and styrene; and acrylic acid, benzyl methacrylate and 2-ethylhexyl acrylate.

[0022] (B) Compound Having an Ethylenically Unsaturated Double Bond The photosensitive resin layer contains a compound having an ethylenically unsaturated double bond in an amount of 20% by mass or more to 50% by mass, preferably 20% by mass to 40% by mass, based on the total mass of solids in the photosensitive resin layer. The ethylenically unsaturated double bond can be polymerized by irradiation with light in the presence of a photopolymerization initiator, thereby curing the photosensitive resin layer.

[0023] The compound having an ethylenically unsaturated double bond includes an acrylate monomer. The amount of the acrylate monomer is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more, based on the total mass of the compound having an ethylenically unsaturated double bond, and may be 100% by mass. The amount of the acrylate monomer is 100% by mass or less, preferably 99% by mass or less, and even more preferably 95% by mass or less, based on the total mass of the compound having an ethylenically unsaturated double bond. When the amount of the acrylate monomer is within the above range, stripper processability, stripper fatigue resistance, and plating penetration resistance tend to be improved. The compound having an ethylenically unsaturated double bond may also contain other monomers, such as methacrylate monomers, as long as it contains an acrylate monomer. When the compound having an ethylenically unsaturated double bond contains an acrylate monomer and a methacrylate monomer, stripper processability, stripper fatigue resistance, plating penetration resistance, and the like tend to be further improved, which is preferable. From the same viewpoint, the mass ratio of the acrylate monomer to the methacrylate monomer (acrylate monomer / methacrylate monomer) is preferably 1.2 or more and 25.0 or less, more preferably 1.2 or more and 20.0 or less, and even more preferably 1.2 or more and 15.0 or less.

[0024] The compound having an ethylenically unsaturated double bond has a double bond equivalent of 150 or more, preferably 160 or more, more preferably 170 or more, even more preferably 180 or more, still more preferably 190 or more, and particularly preferably 200 or more. A double bond equivalent of 150 or more tends to improve resistance to plating penetration, stripper processability, and stripper fatigue resistance. The upper limit of the double bond equivalent of the compound having an ethylenically unsaturated double bond is not limited, but may be, for example, 500 or less, 400 or less, or 300 or less. In this specification, "double bond equivalent" means the molecular weight per ethylenically unsaturated double bond.

[0025] The number of functional groups of the compound having an ethylenically unsaturated double bond may be monofunctional, preferably difunctional or more, more preferably trifunctional or more, even more preferably tetrafunctional or more, and may be pentafunctional or more, or sextuplicate or more. In the present specification, the term "functionality" refers to the number of ethylenically unsaturated double bonds per molecule of the compound, and in the case of an acrylate monomer, for example, it is defined as the number of acryloyl groups per molecule. When the compound having an ethylenically unsaturated double bond contains a compound with a large number of functional groups, the plating penetration resistance of the resist pattern tends to be improved. This effect is particularly pronounced when the acrylate monomer is a tetrafunctional or more acrylate monomer.

[0026] Examples of compounds having a monofunctional ethylenic double bond include compounds in which (meth)acrylic acid is added to one end of a (poly)alkylene glycol; and compounds in which (meth)acrylic acid is added to one end of a (poly)alkylene glycol and a group not having an ethylenic double bond, such as an alkyl group, is added to the other end. The alkylene of the (poly)alkylene glycol is preferably an alkylene group having 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, or a butylene group.

[0027] Examples of bifunctional or higher functional compounds include compounds having a structure in which at least two or all of the hydrogen atoms of the hydroxyl groups in a skeleton such as (poly)alkylene glycol, bisphenol A, trimethylolpropane, glycerin, pentaerythritol, or dipentaerythritol are substituted with a functional group having an ethylenically unsaturated double bond, preferably a functional group having a (meth)acrylate group, and more preferably a functional group having an acrylate group. However, from the viewpoint of resistance to plating penetration, it is more preferable that the compound having an ethylenically unsaturated double bond does not include a compound having a trimethylolpropane skeleton.

[0028] Examples of the compound having a (poly)alkylene glycol skeleton and a bifunctional ethylenically unsaturated double bond include compounds represented by the following general formula (I): [ka] {In the formula, each Y independently represents an alkylene group, each R1 and R2 independently represents a methyl group or a hydrogen atom, and each n independently represents an integer of 1 to 50.} Examples of the compound include compounds represented by the following formula:

[0029] In the general formula (I), each Y is independently an alkylene group preferably having 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, or a butylene group. The (YO) moiety may contain repeating units of different alkylene oxides, or may consist of repeating units of the same alkylene oxide. When the (YO) moiety contains different alkylene oxides, the arrangement may be random, alternating, or block. n represents an integer of 1 to 50, preferably 3 to 20, and more preferably 6 to 10.

[0030] More specifically, examples of the compound represented by the above general formula (I) include: Hexaethylene glycol dimethacrylate, Dimethacrylate of heptaethylene glycol, Dimethacrylate of octaethylene glycol, Dimethacrylate of nonaethylene glycol, Decaethylene glycol dimethacrylate, Hexapropylene glycol dimethacrylate, Heptapropylene glycol dimethacrylate, Octapropylene glycol dimethacrylate, dimethacrylate of nonapropylene glycol, and Decapropylene glycol dimethacrylate etc.

[0031] The double bond equivalent of the (meth)acrylate monomer represented by the general formula (I) is preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, from the viewpoints of resistance to plating penetration, stripper solution processability, and stripper solution fatigue resistance, and is optionally 500 or less, 400 or less, or 300 or less.

[0032] The compound having a bisphenol A skeleton and a bifunctional ethylenically unsaturated double bond includes compounds represented by the following general formula (II): [ka] {In the formula, each Y independently represents an alkylene group, each R1 and R2 independently represents a methyl group or a hydrogen atom, and each n1 and n2 independently represents an integer of 1 to 100.} When the skeleton has an aromatic ring, the resistance to plating penetration tends to be improved.

[0033] In the general formula (II), each Y is independently an alkylene group preferably having 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, or a butylene group. From the viewpoints of imparting flexibility to the cured film, improving film strength, suppressing development aggregation, and increasing the reactivity of the ethylenically unsaturated double bond, it is preferred that at least one or all of the Ys be a 1,2-ethylene group. The (YO) moieties may contain repeating units of different alkylene oxides, or may be composed of repeating units of the same alkylene oxide. When the (YO) moieties contain different alkylene oxides, the arrangement thereof may be random, alternating, or block. n1 and n2 each independently represent an integer of 1 to 100, preferably 1 to 50, more preferably 1 to 20, and even more preferably 1 to 10, and are preferably 2≦n1+n2≦200, more preferably 2≦n1+n2≦100, even more preferably 2≦n1+n2≦40, and particularly preferably 2≦n1+n2≦20.

[0034] More specifically, examples of the compound represented by the general formula (II) include: Diacrylate of ethylene glycol with an average of 1 mole of ethylene oxide added to each end of bisphenol A, Diacrylate of ethylene glycol with an average of 2 moles of ethylene oxide added to each end of bisphenol A, Diacrylate of ethylene glycol with an average of 5 moles of ethylene oxide added to each end of bisphenol A, Diacrylate of alkylene glycol with an average of 6 moles of ethylene oxide and an average of 2 moles of propylene oxide added to both ends of bisphenol A, Diacrylate of alkylene glycol with an average of 15 moles of ethylene oxide and an average of 2 moles of propylene oxide added to both ends of bisphenol A, Dimethacrylate of ethylene glycol with an average of one mole of ethylene oxide added to each end of bisphenol A, Dimethacrylate of ethylene glycol with an average of 2 moles of ethylene oxide added to each end of bisphenol A, Dimethacrylate of ethylene glycol with an average of 5 moles of ethylene oxide added to each end of bisphenol A, Dimethacrylate of alkylene glycol in which an average of 6 moles of ethylene oxide and an average of 2 moles of propylene oxide are added to both ends of bisphenol A, and Dimethacrylate of alkylene glycol with an average of 15 moles of ethylene oxide and an average of 2 moles of propylene oxide added to both ends of bisphenol A Examples include:

[0035] The double bond equivalent of the (meth)acrylate monomer represented by the general formula (II) is preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, from the viewpoints of resistance to plating penetration, stripper solution processability, and stripper solution fatigue resistance, and is optionally 500 or less, 400 or less, or 300 or less.

[0036] As the compound having a trimethylolpropane skeleton and a trifunctional ethylenically unsaturated double bond, there is mentioned the compound represented by the following general formula (III): [ka] {In the formula, n1, n2, and n3 each independently represent an integer of 1 to 25, provided that n1+n2+n3 represents an integer of 3 to 75, and R1, R2, and R3 each independently represent a methyl group or a hydrogen atom.} Examples of the compound include compounds represented by the following formula:

[0037] In the general formula (III), n1, n2, and n3 each independently represent an integer of 1 to 25, preferably 1 to 10, and more preferably 1 to 3. n1+n2+n3 represents an integer of 3 to 75, preferably 3 to 30, more preferably 3 to 15, and even more preferably 3 to 9. n1+n2+n3 is preferably 9 or greater from the viewpoints of suppressing the occurrence of resist tails, improving film strength, and imparting flexibility to the cured film. n1+n2+n3 is preferably 75 or less from the viewpoints of high resolution and adhesion, good release properties, and controlling edge fusing properties.

[0038] Specific examples of the compound represented by the above general formula (III) include: Triacrylate in which an average of 3 moles of ethylene oxide are added to the terminal hydroxyl groups of trimethylolpropane, Triacrylate in which an average of 9 moles of ethylene oxide are added to the terminal hydroxyl groups of trimethylolpropane, A triacrylate in which an average of 15 moles of ethylene oxide in total is added to the terminal hydroxyl groups of trimethylolpropane, and Triacrylate in which an average of 30 moles of ethylene oxide are added to the terminal hydroxyl groups of trimethylolpropane, Examples include:

[0039] The double bond equivalent of the (meth)acrylate monomer represented by the general formula (III) is preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, from the viewpoints of resistance to plating penetration, stripper solution processability, and stripper solution fatigue resistance, and is optionally 500 or less, 400 or less, or 300 or less.

[0040] Examples of compounds having a glycerin skeleton and a trifunctional ethylenically unsaturated double bond include compounds of the following formula (VI): [ka] {In the formula, each Y independently represents an alkylene group, each R independently represents a methyl group or a hydrogen atom, and each n independently represents an integer of 0 to 200.} Examples of the compound include compounds represented by the following formula:

[0041] In general formula (VI), each Y is independently an alkylene group preferably having 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, or a butylene group. From the viewpoints of imparting flexibility to the cured film, improving film strength, suppressing development aggregation, and increasing the reactivity of the ethylenically unsaturated double bond, it is preferred that at least one or all of the Ys be a 1,2-ethylene group. The (YO) moieties may contain repeating units of different alkylene oxides or may be composed of repeating units of the same alkylene oxide. When the (YO) moieties contain different alkylene oxides, the arrangement thereof may be random, alternating, or block. Each n is independently an integer of 0 to 200, and it is preferred that at least one n is an integer of 1 to 200, and more preferred that three n's are integers of 1 to 200. In general formula (VI), n may be 0, i.e., no alkylene oxide moiety may be present. It is preferable that the total number of n's is 1 or more from the viewpoints of suppressing the occurrence of a resist skirt, improving film strength, and imparting flexibility to the cured film, and it is preferable that the total number of n's is 200 or less from the viewpoints of high resolution and adhesion, good release properties, and controlling edge fusing properties.

[0042] The double bond equivalent of the (meth)acrylate monomer represented by the general formula (IV) is preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, from the viewpoints of resistance to plating penetration, stripper solution processability, and stripper solution fatigue resistance, and is optionally 500 or less, 400 or less, or 300 or less.

[0043] As the compound having a pentaerythritol skeleton and a tetrafunctional ethylenically unsaturated double bond, there is mentioned the compound represented by the following general formula (V): [ka] {In the formula, n1, n2, n3, and n4 each independently represent an integer of 1 to 25, n1 + n2 + n3 + n4 is an integer of 4 to 100, R1, R2, R3, and R4 each independently represent a methyl group or a hydrogen atom, R5, R6, R7, and R8 each independently represent an alkylene group, and when there are multiple R5, R6, R7, and R8, the multiple R5, R6, R7, and R8 may be the same as or different from one another.} Examples of the compound include compounds represented by the following formula:

[0044] In general formula (V), R5, R6, R7, and R8 are each independently an alkylene group preferably having 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, or a butylene group. From the viewpoints of imparting flexibility to the cured film, improving film strength, suppressing development aggregation, and increasing the reactivity of the ethylenically unsaturated double bond, it is preferred that at least one or all of R5, R6, R7, and R8 be a 1,2-ethylene group. n1+n2+n3+n4 is 4 to 100, preferably 4 to 80, more preferably 4 to 40, even more preferably 4 to 20, and particularly preferably 4 to 16. It is preferred that n1+n2+n3+n4 is 4 or greater from the viewpoints of suppressing the formation of a resist tail, improving film strength, and imparting flexibility to the cured film. It is preferable that n1+n2+n3+n4 is 100 or less from the viewpoints of high resolution and adhesion, good peeling properties, and controlling edge fusing properties.

[0045] Specific examples of the compound represented by the general formula (V) include: a tetraacrylate in which an average of 4 moles of ethylene oxide in total is added to the terminal hydroxyl groups of pentaerythritol; A tetraacrylate in which an average of 9 moles of ethylene oxide in total are added to the terminal hydroxyl groups of pentaerythritol, a tetraacrylate in which an average of 12 moles of ethylene oxide in total are added to the terminal hydroxyl groups of pentaerythritol; a tetraacrylate in which an average of 15 moles of ethylene oxide in total has been added to the terminal hydroxyl groups of pentaerythritol; a tetraacrylate in which an average of 20 moles of ethylene oxide in total is added to the terminal hydroxyl groups of pentaerythritol; A tetraacrylate in which an average of 28 moles of ethylene oxide in total is added to the terminal hydroxyl groups of pentaerythritol, and A tetraacrylate in which an average of 35 moles of ethylene oxide are added to the terminal hydroxyl groups of pentaerythritol. Examples include:

[0046] The double bond equivalent of the (meth)acrylate monomer represented by the general formula (V) is preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, from the viewpoints of resistance to plating penetration, stripper solution processability, and stripper solution fatigue resistance, and is optionally 500 or less, 400 or less, or 300 or less.

[0047] As the compound having a dipentaerythritol skeleton and a hexafunctional ethylenically unsaturated double bond, there is mentioned the compound represented by the following general formula (VI): [ka] {In the formula, each R independently represents a methyl group or a hydrogen atom, and each n independently represents an integer of 0 to 30.} In general formula (VI), n may be 0, that is, the alkylene oxide moiety may not be present.

[0048] In general formula (VI), n's are each independently an integer of 0 to 30, preferably 1 to 20, more preferably 2 to 10, and even more preferably 3 to 5. The total n's is 0 to 180, preferably 6 to 120, more preferably 12 to 60, and even more preferably 18 to 30. A total n of 1 or more is preferred from the viewpoints of suppressing the occurrence of resist tails, improving film strength, and imparting flexibility to the cured film. A total n of 180 or less is preferred from the viewpoints of high resolution and adhesion, good release properties, and controlling edge fusing properties.

[0049] Specific examples of the hexaacrylate compound represented by general formula (VI) include: Dipentaerythritol hexaacrylate, hexaacrylate in which a total of 1 to 36 moles of ethylene oxide are added to six terminals of dipentaerythritol; Hexaacrylate in which a total of 6 to 30 moles of ethylene oxide are added to the six terminals of dipentaerythritol, Hexaacrylate in which a total of 12 to 30 moles of ethylene oxide are added to the six terminals of dipentaerythritol, Hexaacrylate in which a total of 18 to 30 moles of ethylene oxide are added to the six terminals of dipentaerythritol, and Hexaacrylate in which a total of 1 to 10 moles of ε-caprolactone are attached to the six terminals of dipentaerythritol etc.

[0050] The double bond equivalent of the (meth)acrylate monomer represented by the general formula (VI) is preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, from the viewpoints of resistance to plating submersion, stripper treatment ability, and stripper fatigue resistance, and is optionally 500 or less, 400 or less, or 300 or less.

[0051] The acrylate monomer contained in the compound having an ethylenically unsaturated double bond is preferably at least one of the acrylate compounds represented by general formula (III), general formula (V), and general formula (VI) having a double bond equivalent of 150 or more. However, from the viewpoint of further improving resistance to plating penetration, it is more preferable that the compound does not contain an acrylate compound having a trimethylolpropane skeleton represented by general formula (III).

[0052] The mass ratio (A / B) of the alkali-soluble polymer to the compound having an ethylenically unsaturated double bond is preferably 1.40 or more, more preferably 1.60 or more, and even more preferably 1.80 or more. When the mass ratio of A / B is within the above range, the stripping solution processability and stripping solution fatigue resistance are improved, and wrinkles in the resist during storage tend to be suppressed.

[0053] (C) Photopolymerization initiator A photopolymerization initiator is a compound that can initiate polymerization of a compound having an ethylenically unsaturated double bond by irradiating the compound with light in the presence of the compound.

[0054] The amount of photopolymerization initiator in the photosensitive resin layer is 0.01% by mass to 20% by mass, preferably 0.3% by mass to 10% by mass, and more preferably 1% by mass to 5% by mass, based on the total solids mass of the photosensitive resin layer. When the amount of photopolymerization initiator is 0.01% by mass or more, an exposed pattern with a sufficient remaining film rate after development can be obtained. When the amount of photopolymerization initiator is 20% by mass or less, light can be sufficiently transmitted to the bottom surface of the resist, high resolution can be obtained, and development aggregation in the developer can be suppressed.

[0055] Examples of the photopolymerization initiator include imidazole compounds, aromatic ketones, acridine compounds, and N-aryl-α-amino acid compounds. One type of photopolymerization initiator may be used alone, or two or more types may be used in combination.

[0056] Imidazole compounds tend to improve the plating penetration resistance and suppress footing of resist patterns. Examples of imidazole compounds include imidazoles having an aliphatic group, such as methylimidazole, 2-ethyl-4-methylimidazole, 1-isobutyl-2-methylimidazole, 2-ethyl-4-methylimidazole, ethylimidazole, isopropylimidazole, 2,4-dimethylimidazole, undecylimidazole, heptadecylimidazole, etc.; and imidazoles having an aromatic group, such as 1-benzyl-2-methylimidazole, phenylimidazole (e.g., 2-phenylimidazole), 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, triarylimidazole, or dimers thereof. Among these, from the viewpoint of plating resistance and suppressing the occurrence of base, imidazoles having an aromatic group are preferred, triarylimidazole (for example, lophine) or a dimer thereof is more preferred, and triarylimidazole dimer is even more preferred.

[0057] Examples of the triarylimidazole dimer include 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer.

[0058] Aromatic ketones are preferred from the viewpoint of improving sensitivity. Examples of aromatic ketones include benzophenone, N,N'-tetramethyl-4,4'-dimethylaminobenzophenone (Michler's ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4,4'-bis(diethylamino)benzophenone, 2-benzyl-2-dimethylamino-1-(4-monophornophenyl)-butanone-1, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1. Among these, 4,4'-bis(diethylamino)benzophenone is preferred.

[0059] Acridine compounds are preferred from the viewpoints of improving sensitivity and achieving both high sensitivity and suppression of footing. Examples of acridine compounds include 1,7-bis(9,9'-acridinyl)heptane, 9-phenylacridine, 9-methylacridine, 9-ethylacridine, 9-chloroethylacridine, 9-methoxyacridine, 9-ethoxyacridine, 9-(4-methylphenyl)acridine, 9-(4-ethylphenyl)acridine, 9-(4-n-propylphenyl)acridine, 9-(4-n-butylphenyl)acridine, 9-(4-tert-butylphenyl)acridine, 9-(4-methoxyphenyl)acridine, 9-(4-ethoxyphenyl)acridine, and 9-(4-acetylphenyl). 9-(2-pyridyl)acridine, 9-(3-pyridyl)acridine, and 9-(4-pyridyl)acridine. Among these, 1,7-bis(9,9'-acridinyl)heptane or 9-phenylacridine are preferred in terms of sensitivity, resolution, availability, etc.

[0060] N-aryl-α-amino acid compounds are preferred from the viewpoint of improving sensitivity. Examples of N-aryl-α-amino acid compounds include N-phenylglycine, N-methyl-N-phenylglycine, and N-ethyl-N-phenylglycine.

[0061] Further examples of photopolymerization initiators include, for example: quinones such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone; Benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzyl derivatives such as benzyl methyl ketal; Coumarin compounds; Pyrazoline derivatives such as 1-phenyl-3-(4-tert-butyl-styryl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-butyl-phenyl)-pyrazoline, 1-phenyl-3-(4-biphenyl)-5-(4-tert-octyl-phenyl)-pyrazoline; Examples include:

[0062] <dye> The photosensitive resin layer may further contain a dye. The dye may contain at least one selected from leuco dyes, fluoran dyes, and other coloring substances. When the photosensitive resin layer contains these components, the exposed portions develop color, improving visibility. Furthermore, when an inspection machine or the like reads the alignment marker for exposure, the contrast between the exposed and unexposed portions is increased, making them easier to recognize.

[0063] Examples of leuco dyes include tris(4-dimethylaminophenyl)methane [leuco crystal violet], bis(4-dimethylaminophenyl)phenylmethane [leucomalachite green], etc. From the viewpoint of obtaining good contrast, leuco crystal violet is preferred as the leuco dye.

[0064] Examples of fluoran dyes include 2-(dibenzylamino)fluoran, 2-anilino-3-methyl-6-diethylaminofluoran, 2-anilino-3-methyl-6-dibutylaminofluoran, 2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluoran, 2-anilino-3-methyl-6-N-methyl-N-cyclohexylaminofluoran, 2-anilino-3-chloro-6-diethylaminofluoran, and 2-anilino-3-methyl-6-N-ethyl-N-isoamylaminofluoran. 2-anilino-3-methyl-6-N-ethyl-N-isobutylaminofluoran, 2-anilino-6-dibutylaminofluoran, 2-anilino-3-methyl-6-N-ethyl-N-tetrahydrofurfurylaminofluoran, 2-anilino-3-methyl-6-piperidinoaminofluoran, 2-(o-chloroanilino)-6-diethylaminofluoran, and 2-(3,4-dichloroanilino)-6-diethylaminofluoran.

[0065] The amount of the leuco dye or fluoran dye in the photosensitive resin layer is preferably 0.1% by mass to 10% by mass, more preferably 0.2% by mass to 5% by mass, and even more preferably 0.3% by mass to 1% by mass, based on the total solids mass of the photosensitive resin layer. When the amount of the dye is 0.1% by mass or more, the contrast between exposed and unexposed areas tends to be improved. When the amount of the dye is 10% by mass or less, the storage stability of the photosensitive resin layer tends to be improved, and the generation of aggregates during development tends to be suppressed.

[0066] Examples of coloring substances include fuchsin, phthalocyanine green, auramine base, paramagienta, crystal violet, methyl orange, Nile blue 2B, malachite green (manufactured by Hodogaya Chemical Co., Ltd., Eizen (registered trademark) MALACHITE GREEN), basic blue 7 (e.g., Eizen (registered trademark) Victoria Pure Blue BOH conc., etc.), basic blue 20, and diamond green (manufactured by Hodogaya Chemical Co., Ltd., Eizen (registered trademark) DIAMOND GREEN GH).

[0067] The amount of the coloring substance in the photosensitive resin layer is preferably 0.001% by mass to 1% by mass based on the total solid mass of the photosensitive resin layer. When the amount of the coloring substance is 0.001% by mass or more, contrast tends to be improved, and when it is 1% by mass or less, storage stability tends to be improved.

[0068] <Halogen compounds> The photosensitive resin layer may further contain a halogen compound, and preferably contains a halogen compound in combination with the leuco dye. When the photosensitive resin layer contains a combination of a leuco dye and a halogen compound, adhesion and contrast tend to be improved.

[0069] Examples of halogen compounds include amyl bromide, isoamyl bromide, isobutylene bromide, ethylene bromide, diphenylmethyl bromide, benzyl bromide, methylene bromide, tribromomethylphenylsulfone, carbon tetrabromide, tris(2,3-dibromopropyl)phosphate, trichloroacetamide, amyl iodide, isobutyl iodide, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane, and chlorinated triazine compounds. Among these, tribromomethylphenylsulfone is preferred. Halogen compounds such as tribromomethylphenylsulfone are highly effective when used in combination with an acridine-based compound as a photopolymerization initiator, and are preferred from the viewpoints of improving resolution, adhesion, sensitivity, contrast, tent film puncture resistance, suppressing resist footing, and etching resistance.

[0070] From the above viewpoints, the content of the halogen compound in the photosensitive resin layer is preferably 0.01% by mass based on the total solid mass of the photosensitive resin layer. This content is more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, and particularly preferably 0.5% by mass or more. Furthermore, it is preferable that this content be 3% by mass or less from the viewpoints of maintaining the storage stability of the hue in the photosensitive layer and suppressing the generation of aggregates during development. This content is more preferably 2% by mass or less, even more preferably 1.5% by mass or less.

[0071] <Antioxidants> The photosensitive resin layer may further contain an antioxidant. The antioxidant can improve the thermal stability and storage stability of the photosensitive resin layer. The antioxidant is preferably at least one compound selected from the group consisting of dicarboxylic polymerization inhibitors, benzotriazoles, and carboxybenzotriazoles.

[0072] Examples of radical polymerization inhibitors include p-methoxyphenol, hydroquinone, pyrogallol, naphthylamine, tert-butylcatechol, biphenol, cuprous chloride, 2,6-di-tert-butyl-p-cresol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), and 4,4'-thiobis(6-tert-butyl-m-cresol). , 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, styrenated phenol (for example, Kawaguchi Chemical Industry Co., Ltd., trade name "ANTAGE SP"), tribenzylphenol (for example, Kawaguchi Chemical Industry Co., Ltd., trade name "TBP", a phenol compound having 1 to 3 benzyl groups), and diphenylnitrosamine.

[0073] Examples of benzotriazoles include 1,2,3-benzotriazole, 1-chloro-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-benzotriazole, bis(N-2-ethylhexyl)aminomethylene-1,2,3-tolyltriazole, and bis(N-2-hydroxyethyl)aminomethylene-1,2,3-benzotriazole.

[0074] Examples of carboxybenzotriazoles include 4-carboxy-1,2,3-benzotriazole, 5-carboxy-1,2,3-benzotriazole, N-(N,N-di-2-ethylhexyl)aminomethylenecarboxybenzotriazole, N-(N,N-di-2-hydroxyethyl)aminomethylenecarboxybenzotriazole, N-(N,N-di-2-ethylhexyl)aminoethylenecarboxybenzotriazole, and mixtures thereof. Among these, a mixture of 4-carboxy-1,2,3-benzotriazole and 5-carboxy-1,2,3-benzotriazole is preferred, with the mixing ratio being preferably about 1:1 by mass.

[0075] The total content of the antioxidant is preferably 0.01% by mass to 3% by mass, and more preferably 0.05% by mass to 1% by mass, based on the total solid mass of the photosensitive resin layer. When the amount of the antioxidant is 0.01% by mass or more, the storage stability of the photosensitive resin layer is improved, and when it is 3% by mass or less, sensitivity is maintained and decolorization of the dye tends to be suppressed.

[0076] <Plasticizer> The photosensitive resin layer may contain a plasticizer as needed, for example, glycol esters such as polyethylene glycol, polypropylene glycol, polyoxypropylene polyoxyethylene ether, polyoxyethylene monomethyl ether, polyoxypropylene monomethyl ether, polyoxyethylene polyoxypropylene monomethyl ether, polyoxyethylene monoethyl ether, polyoxypropylene monoethyl ether, and polyoxyethylene polyoxypropylene monoethyl ether; phthalates such as diethyl phthalate; o-toluenesulfonic acid amide, p-toluenesulfonic acid amide, tributyl citrate, triethyl citrate, triethyl acetylcitrate, tri-n-propyl acetylcitrate, tri-n-butyl acetylcitrate, etc.; Propylene glycol, which is propylene oxide added to both ends of bisphenol A, and ethylene glycol, which is ethylene oxide added to both ends of bisphenol A; Aluminum salts with 1 to 3 moles of nitrosophenylhydroxylamine added; These can be used alone or in combination of two or more. Among these, from the viewpoint of resistance to plating penetration, an aluminum salt having 3 moles of nitrosophenylhydroxylamine added thereto is preferred.

[0077] The amount of plasticizer in the photosensitive resin layer is preferably 1% by mass to 50% by mass, and more preferably 1% by mass to 30% by mass, based on the total solid mass of the photosensitive resin layer. When the amount of plasticizer is 1% by mass or more, delay in development time is suppressed and flexibility is imparted to the cured film, while when the amount is 50% by mass or less, insufficient curing and edge fuse tend to be suppressed.

[0078] <solvent> As described below, the photosensitive resin layer can be formed by dissolving each component in a solvent, applying the solution to a support film, and then drying. The resulting photosensitive resin layer may contain residual solvent. Examples of the solvent include ketones such as methyl ethyl ketone (MEK), and alcohols such as methanol, ethanol, and isopropanol.

[0079] <Film Thickness> The film thickness of the photosensitive resin layer is 30 μm or more, preferably more than 40 μm, more preferably more than 70 μm, still more preferably more than 100 μm, even more preferably more than 150 μm, and particularly preferably more than 200 μm. In the plating process, a photosensitive resin laminate having a photosensitive resin layer with a thick film (30 μm or more) is used. Further, since the film thickness of the photosensitive resin layer is thick, generation of laminar air can be suppressed, and a photosensitive resin laminate suitable for the plating process can be obtained. The upper limit of the film thickness of the photosensitive resin layer is not limited, but for example, it can be 500 μm or less, 400 μm or less, or 300 μm or less.

[0080] 〈Absorbance〉 For the photosensitive resin laminate, when the film thickness of the photosensitive resin layer is T (μm) and the absorbance of the photosensitive resin layer at a wavelength of 365 nm is A, it is preferable to satisfy the relationship represented by the following formula: 0 < A / T ≤ 0.007. As the film thickness increases, particularly when T exceeds 100 μm, it becomes difficult for light to reach the bottom of the photosensitive resin layer and crosslinking becomes difficult. However, a photosensitive resin laminate that satisfies the above relationship means that light can easily reach the bottom even with a thick film. Therefore, it is preferable from the viewpoints of improving resolution, reducing bleeding, improving stripping liquid treatment properties, and improving stripping liquid fatigue resistance as compared with a photosensitive resin laminate having A / T > 0.007.

[0081] 〈Support Film〉 As the support film, a transparent film that transmits light radiated from an exposure light source is desirable. Examples of the support film include a polyethylene terephthalate film, a polyvinyl alcohol film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyvinylidene chloride film, a vinylidene chloride copolymer film, a polymethyl methacrylate copolymer film, a polystyrene film, a polyacrylonitrile film, a styrene copolymer film, a polyamide film, and a cellulose derivative film. These films can also be used in a stretched form as necessary. The haze of the support film is preferably 5 or less. The thickness of the support film is preferably 10 μm to 30 μm in consideration of maintaining strength, although a thinner thickness is advantageous in terms of image forming properties and economy.

[0082] <Protective layer> The photosensitive resin laminate may have a protective layer on the surface of the photosensitive resin layer opposite the support film. The protective layer serves to protect the photosensitive resin layer. The protective layer preferably has an appropriate adhesive strength to the photosensitive resin layer. That is, it is preferable that the adhesive strength of the protective layer to the photosensitive resin layer is sufficiently smaller than the adhesive strength of the support film to the photosensitive resin layer, so that the protective layer can be easily peeled off from the photosensitive resin laminate. For example, a polyethylene film, a polypropylene film, or a film with excellent peelability as disclosed in JP-A-59-202457 can be used as the protective layer. The thickness of the protective layer is preferably 10 μm to 100 μm, more preferably 10 to 50 μm.

[0083] <<Method for producing photosensitive resin laminate>> The photosensitive resin laminate can be produced by sequentially laminating a photosensitive resin layer and, if necessary, a protective layer on a support film. Known lamination methods can be used. For example, the components used in the photosensitive resin layer are mixed with a solvent that dissolves them to obtain a uniform solution (coating liquid). Examples of the solvent include ketones such as methyl ethyl ketone (MEK), and alcohols such as methanol, ethanol, and isopropanol. The amount of solvent is preferably such that the viscosity of the coating liquid is 500 to 4,000 mPa·s at 25°C. The coating liquid is applied to a support film and then dried to form a photosensitive resin layer on the support film. Known methods can be used for coating, such as a method using a bar coater or a roll coater. Subsequently, if necessary, a protective layer is laminated on the photosensitive resin layer to produce a photosensitive resin laminate.

[0084] <<Method for forming a resist pattern and a semiconductor bump>> A resist pattern can be formed using the photosensitive resin laminate of the present disclosure. a step of laminating a photosensitive resin layer of the photosensitive resin laminate on a substrate (laminating step); a step of exposing the laminated photosensitive resin laminate to light (exposure step); a step of developing the exposed photosensitive resin laminate to form a resist pattern (developing step); If desired, a step of heating the obtained resist pattern (heating step); may include:

[0085] A semiconductor bump can be formed using the substrate on which the resist pattern is formed. Optionally, a descum and plating pretreatment step; a step of forming semiconductor bumps by copper plating or solder plating the substrate on which the resist pattern has been formed (plating step); If desired, a step of etching the substrate on which the resist pattern has been formed (etching step); If desired, a step of peeling the resist pattern from the substrate (peeling step); may include:

[0086] Hereinafter, a series of methods for forming a resist pattern and semiconductor bumps using a photosensitive resin laminate and a sputtered copper thin film as a substrate will be exemplified.

[0087] (1) Lamination process For example, while peeling off the protective layer of the photosensitive resin laminate, the laminate is adhered to a substrate such as a sputtered copper thin film using, for example, a hot roll laminator. The sputtered copper thin film is preferably a copper-sputtered silicon wafer in which a copper layer is formed on a silicon wafer using a sputtering device.

[0088] (2) Exposure process The exposure process may be, for example: a step of exposing the photosensitive resin layer of the photosensitive resin laminate laminated on the substrate to light through a mask film having a desired wiring pattern in a state where the mask film is in close contact with the photosensitive resin layer; a step of exposing a desired wiring pattern by a direct imaging exposure method; A process of exposing a photomask image by projecting it through a lens. It can be.

[0089] (3)Developing process After the exposure step, the support film on the photosensitive resin layer is peeled off, and the unexposed areas (in the case of a negative-tone) or exposed areas (in the case of a positive-tone) are developed and removed using an alkaline aqueous developer to form a resist pattern on the substrate. The alkaline aqueous solution can be an aqueous solution of Na2CO3 or K2CO3. The alkaline aqueous solution is appropriately selected depending on the characteristics of the photosensitive resin layer, but it is preferable to use an aqueous Na2CO3 solution with a concentration of about 0.2 to 2% by mass and at a temperature of about 20 to 40°C.

[0090] (4)Heating process If desired, the formed resist pattern may be further heated, for example, at about 100°C to 300°C for 1 minute to 5 hours. By carrying out this heating step, it is possible to further improve the adhesion and chemical resistance of the resulting cured resist pattern. In this case, for example, a heating furnace using hot air, infrared, or far-infrared radiation may be used.

[0091] (5) Descumming and pre-plating treatment If desired, the substrate on which the resist pattern has been formed can be subjected to a plasma treatment and / or a water immersion treatment to perform descumming and pre-plating treatment.

[0092] (6) Plating process A conductive pattern can be produced by plating the substrate surface exposed by development (for example, the copper surface of a sputtered copper thin film) with copper or solder. The plating solution is preferably a copper sulfate plating solution.

[0093] (7) Etching process If desired, an etching solution may be sprayed onto the resist pattern formed through the above steps to etch the copper surface not covered by the resist pattern, thereby forming a circuit pattern. Examples of the etching method include acid etching and alkaline etching, and the etching is carried out by a method suitable for the photosensitive resin laminate to be used.

[0094] (8) Peeling process The laminate is then treated with an aqueous solution having a stronger alkalinity than the developer, allowing the resist pattern to be stripped from the substrate. The stripping solution is preferably at least one selected from the group consisting of an aqueous solution of NaOH or KOH having a concentration of about 2 to 5% by mass and a temperature of about 40 to 70°C; SPR920 (product name); and R-101 (product name). A small amount of a water-soluble solvent may be added to the stripping solution.

[0095] The photosensitive resin laminate, resist pattern, and semiconductor bump described above can be used, for example, to form a semiconductor package. [Example]

[0096] <<Measurement and Evaluation Methods>> <Acid equivalent> The acid equivalent was measured by potentiometric titration using a titrator (for example, Hiranuma Automatic Titrator (COM-555) manufactured by Hiranuma Sangyo Co., Ltd.) and a 0.1 mol / L aqueous sodium hydroxide solution.

[0097] <Absorbance> The absorbance (A) of the photosensitive resin laminate at a wavelength of 365 nm was measured using an ultraviolet-visible light (UV-Vis) measuring device (U-3010 spectrophotometer, manufactured by Hitachi High-Technologies Corporation). The protective film was peeled off from the photosensitive resin laminate, and the absorbance at 365 nm was measured, and the obtained value was taken as the absorbance (A). Air was used as a blank sample.

[0098] <Lami Air> The wafer substrate after lamination was observed, and the number of bubbles with a diameter of 1 μm or more that occurred between the photosensitive resin and the wafer was counted and ranked as follows: E (Excellent): 0 bubbles G (Good): 1 to 5 bubbles F (Acceptable): 6 to 10 bubbles P (Not acceptable): 11 or more bubbles

[0099] <Minimum development time> The shortest time required for the unexposed portion of the photosensitive resin layer to completely dissolve was measured as the "minimum development time" and ranked as follows: E (Excellent): Minimum development time is 300 seconds or less G (Good): Minimum development time is greater than 300 seconds and less than 320 seconds F (Acceptable): Minimum development time is over 320 seconds and 340 seconds or less P (Not allowed): Minimum development time value exceeds 340 seconds

[0100] <Resolution> The minimum circular hole mask value at which a hardened resist pattern was normally formed was taken as the resolution, and was ranked as follows: E (Excellent): Resolution 100μm or less G (Good): Over 100 μm, 120 μm or less F (Acceptable): Over 120 μm and up to 130 μm P (unacceptable): Over 130 μm

[0101] <Resist Hem Pull> After patterning 150 μm circular holes and descumming the substrate, the substrate was cut and the length of the resist bottom skirt was observed using an SEM. The results were ranked as follows: Figure 1(a) shows an example of a small resist skirt, and Figure 2(a) shows an example of a large resist skirt. E (Excellent): Bottom length 3 μm or less; G (good): over 3 μm and ≤ 4 μm; F (Fair): Over 4 μm and 5 μm or less; P (unacceptable): Over 5 μm

[0102] <Plating penetration resistance> After copper plating, the hardened resist was peeled off and the bottom of the 150 μm circular copper post on the substrate was observed using an SEM and ranked as follows: Figure 1(b) shows an example of small under-plating, and Figure 2(b) shows an example of large under-plating. E (Excellent): No copper plating penetration G (Good): Copper plating penetration of 1 μm or less F (Acceptable): Copper plating penetration over 1 μm wide and 3 μm wide or less P (not allowed): Copper plating over 3 μm wide

[0103] <Stripping solution processability> exposure: The photosensitive resin laminate was exposed from the support film side to prepare a cured resist. For exposure, an Ultratech Prisma ghi stepper (manufactured by Ultratech Corporation) was used. The exposure dose was 390 mJ / cm. 2 It was carried out at.

[0104] developing: The polyethylene film was peeled off from the exposed photosensitive resin laminate, and the laminate was developed by spraying a 1% by mass Na2CO3 aqueous solution at 30°C for twice the "minimum development time." Then, the polyethylene terephthalate film was peeled off to obtain a cured resist.

[0105] Peelability evaluation 1: The resulting hardened resist was 1.4 cm 3 The resist was immersed in 30 mL of a 3% NaOH stripper at 65°C for 75 minutes. The remaining cured film was then filtered and vacuum dried. The mass of the filtrate was divided by the mass of the cured resist initially immersed to determine the remaining film ratio, and the strippability was evaluated. The results were ranked as follows: E (Excellent): Remaining film rate is 0% G (Good): Residual film rate is over 0% and 10% or less F (Acceptable): Residual film rate is over 10% and 25% or less P (Not acceptable): Remaining film rate exceeds 25%

[0106] Peelability evaluation 2: The same evaluation as in the above stripping treatment evaluation 1 was carried out using SPR920 as the stripping solution. E (Excellent): Remaining film rate is 0% G (Good): Residual film rate is over 0% and 10% or less F (Acceptable): Residual film rate is over 10% and 25% or less P (Not acceptable): Remaining film rate exceeds 25%

[0107] Peelability evaluation 3: The same evaluation as in the above stripping treatment evaluation 1 was carried out except that R-101 was used as the stripping solution. E (Excellent): Remaining film rate is 0% G (Good): Residual film rate is over 0% and 10% or less F (Acceptable): Residual film rate is over 10% and 25% or less P (Not acceptable): Remaining film rate exceeds 25%

[0108] <Stripping solution fatigue> Stripping solution fatigue evaluation 1: The hardened resist obtained by exposure and development under the conditions described in the "Stripping solution processability" section above was 1.4 cm. 3 The substrate was immersed in 30 mL of a 3% NaOH stripping solution at 65°C for 75 minutes, and the remaining cured film was filtered to obtain a filtrate (fatigue stripping solution). After that, the substrate was exposed and developed under the above conditions to obtain 0.007 cm of cured resist. 3 After immersion in 30 mL of this fatigue stripping solution for 75 minutes, the remaining cured film was filtered and vacuum dried. The mass of the filtrate obtained was divided by the mass of the immersed cured resist to determine the remaining film rate, and the stripping processability was evaluated. The results were ranked as follows: E (Excellent): Remaining film rate is 0% G (Good): Residual film rate is over 0% and 10% or less F (Acceptable): Residual film rate is over 10% and 25% or less P (Not acceptable): Remaining film rate exceeds 25%

[0109] Stripping solution fatigue evaluation 2: The fatigue stripper solution prepared in SPR920 was used in the same manner as in the above Stripper Fatigue Evaluation 1. E (Excellent): Remaining film rate is 0% G (Good): Residual film rate is over 0% and 10% or less F (Acceptable): Residual film rate is over 10% and 25% or less P (Not acceptable): Remaining film rate exceeds 25%

[0110] Stripping solution fatigue evaluation 3: The fatigue stripper solution prepared using R-101 was evaluated in the same manner as in the above Stripper Fatigue Evaluation 1. E (Excellent): Remaining film rate is 0% G (Good): Residual film rate is over 0% and 10% or less F (Acceptable): Residual film rate is over 10% and 25% or less P (Not acceptable): Remaining film rate exceeds 25%

[0111] Figure 3 shows an SEM image of copper pillars formed using a photosensitive resin with poor stripper fatigue resistance, after which the cured resist was stripped away. Stripping residue remains between the copper pillars.

[0112] <Resist wrinkles during storage> An 8 cm x 20 cm photosensitive resin laminate was wrapped around a 8.5 cm diameter plastic bottle and left for a certain period of time at 23°C and 50% RH. The degree of wrinkles on the resist surface was evaluated and ranked as follows: E (Excellent): No wrinkles after 12 hours or more G (Good): Over 6 hours, wrinkles appear within 12 hours F (Acceptable): Over 3 hours, wrinkles appear within 6 hours P (Not acceptable): Wrinkles appear within 3 hours

[0113] Example 1 <Preparation of Photosensitive Resin Laminate> The materials shown in Table 1 below were stirred and mixed in the composition shown in Table 2 (where the number for each component indicates the amount (parts by mass) of solid content) to obtain a photosensitive resin coating solution. The obtained coating solution was uniformly applied using a bar coater to the surface of a 16 μm thick polyethylene terephthalate film (Toray Industries, Inc., FB-40) used as a support film, and then dried in a dryer at 95°C for 12 minutes to form a photosensitive resin layer. The thickness (T) of the photosensitive resin layer after drying was 60 μm.

[0114] A 19 μm thick polyethylene film (GF-18, manufactured by Tama Poly Co., Ltd.) was laminated as a protective layer on the surface of the photosensitive resin layer where the support film was not laminated, to obtain a photosensitive resin laminate. The absorbance (A) of the photosensitive resin laminate at a wavelength of 365 nm was 0.4067. The evaluation results are shown in Table 4 below.

[0115] <Semiconductor Bump Fabrication> Base material: When preparing copper posts, a copper-sputtered silicon wafer was used as the substrate, which was a 6-inch silicon wafer on which a copper layer of 2000 angstroms (Å) thickness had been formed using a Canon Anelva sputtering device (L-440S-FHL).

[0116] laminate: While peeling off the polyethylene film from the photosensitive resin laminate, the laminate was laminated onto a silicon wafer preheated to 70°C using a hot roll laminator (TAISEI LAMINATOR CO., LTD., VA-400III) at a roll temperature of 70°C. The air pressure was 0.20 MPa, and the lamination speed was 0.18 m / min.

[0117] exposure: Using a glass chrome mask with a circular hole pattern ranging from 100 μm to 150 μm in 10 μm increments, the laser was irradiated at 390 mJ / cm using an Ultratech Prisma ghi stepper (Ultratech Corporation). 2 The illuminance measured on the substrate surface was 2400 mW / cm 2 It was.

[0118] developing: After exposure, the polyethylene terephthalate film was peeled off from the laminate, and development was carried out by spraying a 1% by mass Na2CO3 aqueous solution at 30°C at a flow rate of 200 mL / min using a spin developing machine (Takizawa Sangyo Co., Ltd., spin developing machine AD-1200).

[0119] Descum and pre-plating treatment: The substrate was subjected to plasma treatment using a low-pressure plasma device (EXAM, manufactured by Shinko Seiki Co., Ltd.) under conditions of 50 Pa, 133 W, O 2 40 mL / min., CF 4 1 mL / min. 1500 sec, for plating pretreatment.

[0120] Copper sulfate plating: Copper posts were prepared by copper plating as described below, followed by stripping the substrate as described below. A copper sulfate plating solution was prepared by adding 20 mL of SC-50 R1 (manufactured by MICROFAB®) and 12 mL of SC-50 R2 (manufactured by MICROFAB®) to 968 mL of SC-50 MU MA. The pre-plated substrate (6 cm x 12.5 cm) was plated for 100 minutes using the prepared copper sulfate plating solution in a Haring Cell Uniform Plating Apparatus (manufactured by Yamamoto Plating Tester Co., Ltd.) with the current adjusted so that copper was deposited at a height of 1 μm per minute. The resulting copper plating film was 100 μm thick. Peeling: The plated substrate was stripped by heating at 65°C for 70 minutes using a stripping solution containing 3% NaOH, SPR920 (manufactured by KANTO-PPC), and R-101 (manufactured by Mitsubishi Gas Chemical Co., Inc.).

[0121] Examples 2 to 20 and Comparative Examples 1 to 7 A photosensitive resin laminate, a resist pattern, and a semiconductor bump were formed and evaluated in the same manner as in Example 1, except that the materials and compositions were changed as shown in Tables 1 to 3. The evaluation results are shown in Tables 4 and 5.

[0122] [Table 1]

[0123] [Table 2]

[0124] [Table 3]

[0125] [Table 4]

[0126] [Table 5] [Industrial Applicability]

[0127] The photosensitive resin laminate of the present disclosure can be used to form a resist pattern and a semiconductor bump, and the resist pattern and the semiconductor bump can be used, for example, to form a semiconductor package.

Claims

1. A photosensitive resin laminate comprising a support film and a photosensitive resin layer laminated on the support film, wherein the photosensitive resin layer comprises: (A) 30% by mass to 70% by mass of an alkali-soluble polymer; (B) 20% by mass to 50% by mass of a compound having an ethylenically unsaturated double bond; (C) 0.01% by mass to 20% by mass of a photopolymerization initiator; Contains the alkali-soluble polymer contains a (meth)acrylate having an aromatic group as a copolymerization component, the acidic group contained in the alkali-soluble polymer is a carboxyl group, the acid equivalent is 350 or more, and the alkali-soluble polymer does not have an ethylenically unsaturated double bond; the compound having an ethylenically unsaturated double bond is an acrylate monomer, or an acrylate monomer and a methacrylate monomer, and contains 50% by mass to 100% by mass of the acrylate monomer based on the total mass of the compound having an ethylenically unsaturated double bond; the compound having an ethylenically unsaturated double bond has a functionality of 2 to 6 and a double bond equivalent of 150 to 500; The thickness of the photosensitive resin layer is 30 μm or more, The photosensitive resin laminate is a photosensitive resin laminate used in a plating method.

2. 2. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer contains, as copolymerization components, only a (meth)acrylate having an aromatic group and at least one compound selected from the group consisting of a carboxylic acid, a carboxylate, and an acid anhydride having one polymerizable unsaturated group in the molecule, an alkyl (meth)acrylate, and an aromatic vinyl compound.

3. 3. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer contains benzyl (meth)acrylate as a copolymerization component.

4. 4. The photosensitive resin laminate according to claim 1, wherein, when the film thickness of the photosensitive resin layer is T [μm] and the absorbance of the photosensitive resin layer at a wavelength of 365 nm is A, the photosensitive resin laminate satisfies the relationship represented by the following formula: 0<A / T≦0.

007.

5. 5. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer contains 45% by mass to 95% by mass of benzyl (meth)acrylate as a copolymerization component.

6. 6. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer contains 50% by mass or more of benzyl (meth)acrylate as a copolymerization component.

7. 6. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer contains 70% by mass or more of benzyl (meth)acrylate as a copolymerization component.

8. 8. The photosensitive resin laminate according to claim 1, wherein the compound having an ethylenically unsaturated double bond contains an acrylate monomer and a methacrylate monomer.

9. 9. The photosensitive resin laminate according to claim 8, wherein a mass ratio of the acrylate monomer to the methacrylate monomer (acrylate monomer / methacrylate monomer) is 1.2 or more and 25.0 or less.

10. 10. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer does not contain styrene or a styrene derivative as a copolymerization component.

11. 11. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer has an acid equivalent of 370 or more.

12. 11. The photosensitive resin laminate according to claim 1, wherein the alkali-soluble polymer has an acid equivalent of 410 or more.

13. The photosensitive resin laminate according to any one of claims 1 to 12, wherein the compound having an ethylenically unsaturated double bond does not include a compound having a trimethylolpropane skeleton.

14. The photosensitive resin laminate according to any one of claims 1 to 13, wherein the compound having an ethylenically unsaturated double bond includes a tetrafunctional or higher functional compound.

15. The photosensitive resin laminate according to any one of claims 1 to 14, wherein the compound having an ethylenically unsaturated double bond contains 50 mass% to 99 mass% of an acrylate monomer, based on the total mass of the compound having an ethylenically unsaturated double bond.

16. The photosensitive resin laminate according to any one of claims 1 to 14, wherein the compound having an ethylenically unsaturated double bond contains 60 mass% to 99 mass% of an acrylate monomer, based on the total mass of the compound having an ethylenically unsaturated double bond.

17. The photosensitive resin laminate according to any one of claims 1 to 14, wherein the compound having an ethylenically unsaturated double bond contains 70 mass% to 99 mass% of an acrylate monomer, based on the total mass of the compound having an ethylenically unsaturated double bond.

18. 18. The photosensitive resin laminate according to any one of claims 1 to 17, wherein the compound having an ethylenically unsaturated double bond has a double bond equivalent of 200 or more.

19. The photosensitive resin laminate according to any one of claims 1 to 18, wherein the mass ratio (A / B) of the alkali-soluble polymer to the compound having an ethylenically unsaturated double bond is 1.40 or more.

20. The photosensitive resin laminate according to any one of claims 1 to 18, wherein the mass ratio (A / B) of the alkali-soluble polymer to the compound having an ethylenically unsaturated double bond is 1.60 or more.

21. The photosensitive resin laminate according to any one of claims 1 to 18, wherein the mass ratio (A / B) of the alkali-soluble polymer to the compound having an ethylenically unsaturated double bond is 1.80 or more.

22. The photosensitive resin laminate according to any one of claims 1 to 21, wherein the photopolymerization initiator contains a 2,4,5-triarylimidazole dimer.

23. The photosensitive resin laminate according to any one of claims 1 to 22, wherein the photosensitive resin layer has a thickness of more than 40 µm.

24. The photosensitive resin laminate according to any one of claims 1 to 22, wherein the photosensitive resin layer has a thickness of more than 70 µm.

25. The photosensitive resin laminate according to any one of claims 1 to 22, wherein the photosensitive resin layer has a thickness of more than 100 µm.

26. The photosensitive resin laminate according to any one of claims 1 to 22, wherein the photosensitive resin layer has a thickness of more than 150 µm.

27. The photosensitive resin laminate according to any one of claims 1 to 22, wherein the photosensitive resin layer has a thickness of more than 200 µm.

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