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, precision processing of metals, etc. 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 the substrate, the photosensitive resin layer, and the support. The photosensitive resin layer is exposed through a photomask having a desired wiring pattern. The support is peeled off from the exposed laminate, and the non-exposed or exposed portions are dissolved or dispersed and removed by a developer to form a resist pattern on the substrate. A substrate with a resist pattern can be subjected to plating treatment such as copper plating or solder plating to form bumps for semiconductors and the like.

[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] JP 2011-227309 A [Patent Document 3] International Publication No. 2011 / 037182 [Patent Document 4] JP 2013-246387 A [Patent Document 5] JP 2014-002285 A [Patent Document 6] JP 2014-126701 A [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. In plating methods, a photosensitive resin laminate having a thick photosensitive resin layer is generally used, and high resolution and reduction in the phenomenon in which a part of the photosensitive resin layer is not removed and remains in a tapered shape (so-called "footing") are required.

[0007] If a photosensitive resin with poor processability in a stripping solution is used, the stripped cured resist does not dissolve and remains as a residue in the stripping solution. The retained stripping residue causes the pump of the stripper to clog. For this reason, the processability of the photosensitive resin in the stripping solution (hereinafter also referred to as "stripping processability") is required. In addition, the stripping solution used to remove the cured resist pattern consumes its contained components as it is removed. If a photosensitive resin that consumes components significantly is used, problems such as stripping residue are likely to occur and productivity will decrease unless the frequency of stripping solution preparation is increased. For this reason, it is required to reduce the frequency of stripping solution preparation (hereinafter also referred to as "stripping solution fatigue").

[0008] Photosensitive resins used in plating techniques are also required to reduce the phenomenon in which plating sinks into the bottom of a hardened resist pattern during plating (hereinafter, also referred to as "plating sinking").

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

[0010] Examples of embodiments of the present disclosure are listed in the following items. [1] A photosensitive resin laminate comprising a support film and a photosensitive resin layer laminated on the support film, the photosensitive resin layer comprising: (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 an aromatic group-containing (meth)acrylate 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] 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 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 a 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 a 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 a 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. Effect of the Invention

[0011] According to the present disclosure, there is provided a photosensitive resin laminate which can improve resolution, reduce bottom shapes, improve stripper processability and stripper fatigue resistance, and suppress plating penetration. [Brief description 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. [Diagram 2] FIG. 2 is a pair of SEM photographs showing an example in which the resist edge (a) and plating penetration (b) are large. [Diagram 3] FIG. 3 is an SEM photograph showing defects that occur when a copper pillar is formed using a photosensitive resin that has poor stripping solution fatigue resistance, and then peeled off. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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. If necessary, the photosensitive resin layer may have a protective layer on the surface opposite to the support film.

[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 the components (A) to (C), a polymer other than the component (A), a monomer other than the component (B), and an initiator other than the component (C), as well as other components such as dyes, antioxidants, and plasticizers.

[0015] (A) Alkali-soluble polymer The alkali-soluble polymer contains an aromatic group-containing (meth)acrylate 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 content mass of the photosensitive resin layer. By containing an aromatic group-containing (meth)acrylate as a copolymerization component, there are advantages such as shortening the minimum development time, improving resolution, reducing footing, and improving plating penetration resistance. In the present specification, the alkali-soluble polymer is 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, and examples thereof include a phenyl group, a benzyl group, a biphenyl group, and a naphthyl group. The hydrogen atom of the aromatic group may be unsubstituted or substituted, and when substituted, the substituent may be a hydrocarbon group having 1 to 5 carbon atoms, a hydroxyl group, a halogen group, and the like. From the viewpoint of shortening the minimum development time, improving the resolution, reducing the footing, and further improving the plating submergibility, the (meth)acrylate having an aromatic group preferably contains benzyl (meth)acrylate. The ratio 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. When the ratio of benzyl (meth)acrylate is high, the stripping solution processability is improved. 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. By having an acid equivalent of 350 or more, there are advantages such as shortening the minimum development time, improving the resolution, preventing fatigue of the stripping solution, and preventing wrinkles of the resist during storage. The upper limit of the acid equivalent is not limited, but is preferably, for example, 600 or less. By having an acid equivalent of 600 or less, it is possible to improve the 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. When the weight average molecular weight is 5,000 or more, the development aggregates are reduced, and the properties of the unexposed film, such as edge fuse property and cut chip property, in the photosensitive resin laminate are improved. On the other hand, when the weight average molecular weight is 500,000 or less, the solubility in the developer is improved. The edge fuse property is a property that suppresses the phenomenon that the photosensitive resin layer protrudes from the end face of the roll when the photosensitive resin laminate is wound into a roll. The cut chip property is a property that suppresses the phenomenon that the chip flies when the unexposed film is cut with a cutter. If the cut chipping 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 a 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 the number of carbon atoms may be, for example, 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, or 6 or more, 12 or less, 11 or less, 10 or less, 9 or less, or 8 or less. More specifically, the alkyl group of the alkyl (meth)acrylate may be, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, an ethylhexyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. Among these, from the viewpoint of shortening the development time and reducing the tailing of the resist pattern, the 2-ethylhexyl group is more preferable. By using, for example, 2-ethylhexyl (meth)acrylate as a 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] Preferable 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 specifically, 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 solid mass of the photosensitive resin layer. The ethylenically unsaturated double bond can be polymerized by irradiating light in the presence of a photopolymerization initiator to harden 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. By the amount of the acrylate monomer being within the above range, the stripper processability, stripper fatigue resistance, and plating submersion resistance tend to be improved. The compound having an ethylenically unsaturated double bond may 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, it is preferable because the stripper processability, stripper fatigue resistance, plating submersion resistance, and the like tend to be further improved. 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 further 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, even more preferably 190 or more, and particularly preferably 200 or more. When the double bond equivalent is 150 or more, the plating penetration resistance, stripper processability, and stripper fatigue resistance tend to be improved. 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, the "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 hexafunctional or more. In the present specification, the "number of functional groups" 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 submergence resistance of the resist pattern tends to be improved. This effect is particularly noticeable when the acrylate monomer is a tetrafunctional or more acrylate monomer.

[0026] Examples of the compound having a monofunctional ethylenic double bond include a compound in which (meth)acrylic acid is added to one end of a (poly)alkylene glycol; and a compound 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, a butylene group, etc.

[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] As the compound having a (poly)alkylene glycol skeleton and a difunctional ethylenically unsaturated double bond, there may be mentioned 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 above general formula (I), each Y is independently an alkylene group having preferably 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, and a butylene group. The (YO) portion may contain repeating units of different alkylene oxides, or may be composed of repeating units of the same alkylene oxide. When the (YO) portion contains different alkylene oxides, the arrangement may be random, alternating, or block arrangement. n represents an integer of 1 to 50, preferably 3 to 20, more preferably 6 to 10.

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

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

[0032] As a compound having a bisphenol A skeleton and a difunctional ethylenically unsaturated double bond, there is a compound 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.} The compound having an aromatic ring in the skeleton tends to improve resistance to plating penetration.

[0033] In the above general formula (II), each Y is independently an alkylene group having preferably 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 preferable that at least one or all of the Ys are 1,2-ethylene groups. The (YO) portion may contain repeating units of different alkylene oxides, or may be composed of repeating units of the same alkylene oxide. When the (YO) portion contains different alkylene oxides, the arrangement may be a random, alternating, or block arrangement. 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 above 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 1 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 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, 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. etc.

[0035] The double bond equivalent of the (meth)acrylate monomer represented by the above general formula (II) is, from the viewpoints of resistance to plating penetration, stripper solution processability and stripper solution fatigue resistance, preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, 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 are each independently an integer of 1 to 25, provided that n1+n2+n3 is an integer of 3 to 75, and R1, R2, and R3 are each independently a methyl group or a hydrogen atom.} Examples of the compound include compounds represented by the following formula:

[0037] In the above general formula (III), n1, n2, and n3 are each independently an integer of 1 to 25, preferably 1 to 10, and more preferably 1 to 3. n1+n2+n3 is an integer of 3 to 75, preferably 3 to 30, more preferably 3 to 15, and even more preferably 3 to 9. When n1+n2+n3 is 9 or more, it is preferable from the viewpoints of suppressing the occurrence of resist tails, improving film strength, and imparting flexibility to the cured film. When n1+n2+n3 is 75 or less, it is preferable from the viewpoints of high resolution and adhesion, good peeling 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 have been added to the terminal hydroxyl group of trimethylolpropane, and Triacrylate in which an average of 30 moles of ethylene oxide are added to the terminal hydroxyl groups of trimethylolpropane. etc.

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

[0040] As a compound having a glycerin skeleton and a trifunctional ethylenically unsaturated double bond, there may be mentioned a compound represented by 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 the general formula (VI), each Y is independently an alkylene group having preferably 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, and a butylene group. From the viewpoint 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 preferable that at least one or all of the Ys are 1,2-ethylene groups. The (YO) portion may contain repeating units of different alkylene oxides, or may be composed of repeating units of the same alkylene oxide. When the (YO) portion contains different alkylene oxides, the arrangement may be random, alternating, or block arrangement. Each n is independently an integer of 0 to 200, and it is preferable that at least one n is an integer of 1 to 200, and it is more preferable that three n's are integers of 1 to 200. In the general formula (VI), n may be 0, that is, the alkylene oxide portion may not be present. It is preferable that the total of n is 1 or more from the viewpoints of suppressing the occurrence of resist tails, improving film strength, and imparting flexibility to the cured film.It is preferable that the total of n is 200 or less from the viewpoints of high resolution and adhesion, good peeling properties, and controlling edge fuse properties.

[0042] The double bond equivalent of the (meth)acrylate monomer represented by the above general formula (IV) is, from the viewpoints of resistance to plating penetration, stripper solution processability and stripper solution fatigue resistance, preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, 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 each other.} Examples of the compound include compounds represented by the following formula:

[0044] In the general formula (V), R5, R6, R7 and R8 are each independently an alkylene group having preferably 2 to 10 carbon atoms, more preferably 2 to 4 carbon atoms, such as a 1,2-ethylene group, a 1,2-propylene group, a butylene group, etc. From the viewpoint 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 preferable that at least one or all of R5, R6, R7 and R8 is 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. When n1+n2+n3+n4 is 4 or more, it is preferable from the viewpoint of suppressing the occurrence of resist tails, 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 control of edge fusing properties.

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

[0046] The double bond equivalent of the (meth)acrylate monomer represented by the above general formula (V) is, from the viewpoints of resistance to plating penetration, stripper solution processability and stripper solution fatigue resistance, preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, 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 the general formula (VI), n may be 0, that is, the alkylene oxide portion may not be present.

[0048] In the general formula (VI), n is 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 of n is 0 to 180, preferably 6 to 120, more preferably 12 to 60, and even more preferably 18 to 30. When the total of n is 1 or more, it is preferable from the viewpoints of suppressing the occurrence of resist tails, improving film strength, and imparting flexibility to the cured film. When the total of n is 180 or less, it is preferable from the viewpoints of high resolution and adhesion, good peeling properties, and controlling edge fusing properties.

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

[0050] The double bond equivalent of the (meth)acrylate monomer represented by the above general formula (VI) is, from the viewpoints of resistance to plating submersion, stripper processability and stripper fatigue resistance, preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, and still more preferably 180 or more, 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 the resistance to plating penetration, it is more preferable not to 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 resist wrinkles 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 the 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 solid mass of the photosensitive resin layer. When the amount of the photopolymerization initiator is 0.01% by mass or more, an exposure pattern having a sufficient remaining film rate after development can be obtained. When the amount of the 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. The photopolymerization initiator may be used alone or in combination of two or more kinds.

[0056] Imidazole compounds tend to suppress the plating penetration resistance and 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 (2-phenylimidazole, etc.), 2-phenyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, triarylimidazole, or dimers thereof. Among these, from the viewpoints of plating resistance and suppressing the occurrence of bottoming, 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, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propanone-1, etc. Among them, 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, 9-(4-acetylphenyl)acridine, and 9-(4-acetylphenyl)acridine. 1,7-bis(9,9'-acridinyl)heptane or 9-phenylacridine are preferred from the viewpoints 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 the photopolymerization initiator 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; etc.

[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 portion develops color, improving visibility. Furthermore, when an inspection machine or the like reads the alignment marker for exposure, the contrast between the exposed portion and the unexposed portion becomes large, making it easier to recognize.

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

[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, 2-anilino-3-methyl-6-N-ethylaminofluoran, 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 solid mass of the photosensitive resin layer. When the amount of the dye is 0.1% by mass or more, the contrast between the exposed and unexposed areas tends to improve. When the amount of the dye is 10% by mass or less, the storage stability of the photosensitive resin layer tends to improve, and the generation of aggregates during development tends to be suppressed.

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

[0067] The amount of the coloring material 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 material is 0.001% by mass or more, the contrast is improved, and when it is 1% by mass or less, the 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 them, the halogen compound is preferably tribromomethylphenylsulfone. A halogen compound such as tribromomethylphenylsulfone is highly effective when used in combination with an acridine compound as a photopolymerization initiator, and is preferable from the viewpoints of improving resolution, improving adhesion, improving sensitivity, improving contrast, improving resistance to tent film piercing, suppressing resist skirting, and improving 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. In addition, it is preferable that this content is 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, and 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. As the antioxidant, at least one compound selected from the group consisting of dicarboxy polymerization inhibitors, benzotriazoles, and carboxybenzotriazoles is preferable.

[0072] Examples of the radical polymerization inhibitor 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 them, a mixture of 4-carboxy-1,2,3-benzotriazole and 5-carboxy-1,2,3-benzotriazole is preferred, and the mixing ratio is preferably about 1:1 by mass.

[0075] The total content of the antioxidant is preferably 0.01% by mass to 3% by mass, 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, the sensitivity is maintained and decolorization of the dye tends to be suppressed.

[0076] <Plasticizer> The photosensitive resin layer may contain a plasticizer as necessary. Examples of the plasticizer include 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, acetyl triethyl citrate, acetyl tri-n-propyl citrate, acetyl tri-n-butyl citrate, etc; Propylene glycol, which is made by adding propylene oxide to both ends of bisphenol A, and ethylene glycol, which is made by adding ethylene oxide 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 the plasticizer in the photosensitive resin layer is preferably 1% by mass to 50% by mass, more preferably 1% by mass to 30% by mass, based on the total solid content of the photosensitive resin layer. When the amount of the plasticizer is 1% by mass or more, the delay in development time is suppressed and flexibility is imparted to the cured film, and when the amount is 50% by mass or less, insufficient curing and edge fuse tend to be suppressed.

[0078] <solvent> The photosensitive resin layer can be formed by dissolving each component in a solvent, applying the solution onto a support film, and then drying the solution, as described below. 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 exceeding 40 μm, more preferably exceeding 70 μm, still more preferably exceeding 100 μm, even more preferably exceeding 150 μm, and particularly preferably exceeding 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 large, the 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 can be, for example, 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 fringing, improving stripping solution processability, and improving stripping solution fatigue 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 emitted from the exposure light source is desirable. Examples of the support film include polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene film, polyacrylonitrile film, styrene copolymer film, polyamide film, and 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 one is advantageous in terms of image formability and economy.

[0082] <Protective layer> The photosensitive resin laminate may have a protective layer on the surface of the photosensitive resin layer opposite to the support film. The protective layer plays a role in protecting 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, and the protective layer can be easily peeled off from the photosensitive resin laminate. As the protective layer, for example, a polyethylene film, a polypropylene film, a film with excellent peelability as shown in JP-A-59-202457, and the like can be used. 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. A known method can be adopted as the lamination method. For example, each component used in the photosensitive resin layer is 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 the 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 onto a support film and then dried to form a photosensitive resin layer on the support film. A known method can be adopted for the coating, and examples include a method using a bar coater or a roll coater. Next, if necessary, a protective layer is laminated on the photosensitive resin layer to produce a photosensitive resin laminate.

[0084] <<Method of forming resist pattern and semiconductor bump>> A resist pattern can be formed using the photosensitive resin laminate of the present disclosure. A method for forming a resist pattern includes the following steps: a step of laminating a photosensitive resin layer of the photosensitive resin laminate onto a substrate (lamination 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 by 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 is 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 a semiconductor bump 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 by 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; or A process in which the image of a photomask is projected through a lens to expose the substrate. 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 area (in the case of a negative type) or the exposed area (in the case of a positive type) is developed and removed using an aqueous alkaline solution to form a resist pattern on the substrate. As the aqueous alkaline solution, an aqueous Na2CO3 or K2CO3 solution can be used. The aqueous alkaline solution is appropriately selected according to 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 mass% and at 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 obtained cured resist pattern. For heating in this case, for example, a heating furnace using hot air, infrared, or far infrared rays can 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 descum 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 to form 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 Thereafter, the laminate is treated with an aqueous solution having a stronger alkalinity than the developer, and the resist pattern can be peeled off 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, in forming a semiconductor package. EXAMPLES

[0096] Measurement and evaluation methods <Acid equivalent> The acid equivalent was measured by a potentiometric titration method 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 (Hitachi High-Technologies Corporation, U-3010 spectrophotometer). 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] <Lamiair> The wafer substrate after lamination was observed, and the number of air bubbles having 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 air 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 was ranked as follows: E (Excellent): Minimum development time value 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 greater than 320 seconds and less than 340 seconds P(Not acceptable): 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 (not acceptable): Over 130 μm

[0101] <Resist Hem Pull> A 150μm circular hole was patterned, the descummed substrate was cut, and the length of the resist bottom was observed with an SEM. The results were ranked as follows. Figure 1(a) shows an example of a small resist bottom, and Figure 2(a) shows an example of a large resist bottom. E (Excellent): Bottom length 3μm or less; G (good): over 3 μm, 4 μm or less; F (Fair): More than 4 μm, 5 μm or less; P (not acceptable): Over 5μm

[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 with an SEM and ranked as follows: Figure 1(b) shows an example of small plating penetration, and Figure 2(b) shows an example of large plating penetration. E (Excellent): No copper plating penetration G (Good): Copper plating penetration of 1 μm or less F (OK): Copper plating penetration over 1μm and below 3μm P (not allowed): Copper plating over 3μm 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 Co., Ltd.) was used. The exposure dose was 390 mJ / cm2. 2 It was carried out in.

[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 3% NaOH stripping solution at 65°C for 75 minutes. The remaining cured film was then filtered and vacuum dried, and the mass of the filtrate was divided by the mass of the cured resist initially immersed to determine the remaining film ratio, and the stripping processability was evaluated. The results were ranked as follows: E (Excellent): The remaining film rate is 0% G (Good): Residual film rate is greater than 0% and less than 10% F (Fair): Residual film rate is over 10% and 25% or less P (Not acceptable): Residual film rate exceeds 25%

[0106] Peelability evaluation 2: The same evaluation as in the above stripping processability evaluation 1 was performed except that SPR920 was used as the stripping solution. E (Excellent): The remaining film rate is 0% G (Good): Residual film rate is greater than 0% and less than 10% F (Fair): Residual film rate is over 10% and 25% or less P (Not acceptable): Residual film rate exceeds 25%

[0107] Peelability evaluation 3: The same evaluation as in the above stripping processability evaluation 1 was performed except that R-101 was used as the stripping solution. E (Excellent): The remaining film rate is 0% G (Good): Residual film rate is greater than 0% and less than 10% F (Fair): Residual film rate is over 10% and 25% or less P (Not acceptable): Residual 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-mentioned conditions to obtain a 0.007 cm thick cured resist. 3 After immersing the sample in 30 mL of the fatigue stripping solution for 75 minutes, the remaining cured film was filtered and vacuum dried, and the mass of the filtrate was divided by the mass of the immersed cured resist to determine the remaining film rate and evaluate the stripping processability. E (Excellent): The remaining film rate is 0% G (Good): Residual film rate is greater than 0% and less than 10% F (Fair): Residual film rate is over 10% and 25% or less P (Not acceptable): Residual film rate exceeds 25%

[0109] Stripping solution fatigue evaluation 2: The fatigue stripping solution prepared using SPR920 was used in the fatigue evaluation 1 of the stripping solution described above. E (Excellent): The remaining film rate is 0% G (Good): Residual film rate is greater than 0% and less than 10% F (Fair): Residual film rate is over 10% and 25% or less P (Not acceptable): Residual film rate exceeds 25%

[0110] Stripping solution fatigue evaluation 3: The fatigue stripping solution prepared using R-101 was used in the same manner as in the above-mentioned Stripping Solution Fatigue Evaluation 1. E (Excellent): The remaining film rate is 0% G (Good): Residual film rate is greater than 0% and less than 10% F (Fair): Residual film rate is over 10% and 25% or less P (Not acceptable): Residual film rate exceeds 25%

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

[0112] <Resist wrinkles during storage> A photosensitive resin laminate measuring 8 cm x 20 cm was wrapped around a plastic bottle with a diameter of 8.5 cm and left for a certain period of time under conditions of 23°C and 50% RH. The occurrence 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 (Fair): 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 numbers for each component indicate the amount (parts by mass) of solid content) to obtain a photosensitive resin coating liquid. The obtained coating liquid 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 dried for 12 minutes in a dryer at 95° C. 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 Tamapoly Co., Ltd.) was laminated as a protective layer on the surface of the photosensitive resin layer on which 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] (Fabrication of Semiconductor Bumps) Base material: When preparing copper posts, a copper-sputtered silicon wafer was used as a substrate, which was a 6-inch silicon wafer on which a copper layer of 2000 angstroms (Å) was 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 on 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 from 100 μm to 150 μm in 10 μm increments, the laser was irradiated with 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: The polyethylene terephthalate film was peeled off from the exposed 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 developer (Takizawa Sangyo Co., Ltd., spin developer AD-1200).

[0119] Descum and pre-plating: 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, O2 40 mL / min., CF41 mL / min. 1500 sec, for pre-plating treatment.

[0120] Copper sulfate plating: Copper plating was performed as follows, and the substrate was peeled off as described below to prepare copper posts. 20 mL of SC-50 R1 (manufactured by MICROFAB (registered trademark)) and 12 mL of SC-50 R2 (manufactured by MICROFAB (registered trademark)) were added to 968 mL of SC-50 MU MA to prepare a copper sulfate plating solution. The substrate (6 cm x 12.5 cm) after plating pretreatment was plated for 100 min using the prepared copper sulfate plating solution with a Haring cell uniform plating device (manufactured by Yamamoto Plating Tester Co., Ltd.) by adjusting the current value so that copper was precipitated at a height of 1 μm per minute. The obtained copper plating film had a thickness of 100 μm. Peeling: The plated substrate was heated 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.) to remove the plating.

[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, the photosensitive resin layer comprising: (A) 30% by mass to 70% by mass of an alkali-soluble polymer; (B) a compound having 20% ​​by mass to 50% by mass of an ethylenically unsaturated double bond; (C) 0.01% by mass to 20% by mass of a photopolymerization initiator; Contains The alkali-soluble polymer contains an aromatic group-containing (meth)acrylate as a copolymerization component, has an acid equivalent of 350 or more, and does not contain an ethylenically unsaturated double bond; 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. The photosensitive resin laminate described in claim 1, wherein the alkali-soluble polymer contains as copolymerization components only at least one compound selected from the group consisting of (meth)acrylate having an aromatic group and carboxylic acid, carboxylate and acid anhydride having one polymerizable unsaturated group in the molecule, alkyl (meth)acrylate, and 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. The photosensitive resin laminate according to any one of claims 1 to 3, wherein when a film thickness of the photosensitive resin layer is T [µm] and an absorbance of the photosensitive resin layer at a wavelength of 365 nm is A, a relationship represented by the following formula: 0<A / T≦0.007 is satisfied.

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 compound having four or more functionalities.

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% 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. 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 a 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 a 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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