WO2023085409A1 - Adhesive tape and processing method - Google Patents

Adhesive tape and processing method Download PDF

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Publication number
WO2023085409A1
WO2023085409A1 PCT/JP2022/042144 JP2022042144W WO2023085409A1 WO 2023085409 A1 WO2023085409 A1 WO 2023085409A1 JP 2022042144 W JP2022042144 W JP 2022042144W WO 2023085409 A1 WO2023085409 A1 WO 2023085409A1
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Prior art keywords
meth
adhesive tape
acrylic polymer
weight
parts
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PCT/JP2022/042144
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French (fr)
Japanese (ja)
Inventor
裕紀 木元
秀 田中
浩子 野上
水貴 蓮見
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デンカ株式会社
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Publication of WO2023085409A1 publication Critical patent/WO2023085409A1/en

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26

Definitions

  • the present invention relates to an adhesive tape and a processing method using it.
  • a semiconductor wafer processing tape is attached to the adherends to temporarily fix the adherends during dicing. As a result, it is possible to prevent chips from flying out during singulation. After dicing, the tape for semiconductor wafer processing is expanded, and the individualized adherends are picked up (peeled off) from the tape for semiconductor wafer processing.
  • an adhesive tape is mainly used in which an adhesive layer that undergoes a curing reaction when irradiated with ultraviolet rays is applied to a film base material that is transparent to ultraviolet rays.
  • the adhesive layer is irradiated with UV rays after dicing, and the curing reaction proceeds to reduce the adhesive strength of the adhesive layer. Can be picked up easily.
  • the push-up pin pushes up the individualized adherend and picks it up.
  • it is required to reduce the adhesive residue of the adhesive tape on the adherend and to be able to pick up even a low pin height at a high yield.
  • the adhesive tape when the adhesive tape is attached to the adherend, if the wettability of the adhesive to the adherend is not good, the glue cannot follow the steps of the adherend and air bubbles form. In such a case, the adhesive may be cured poorly due to oxygen inhibition or the like during ultraviolet irradiation, and the adhesive may remain uncured on the adherend. In addition, if the adhesive strength to the adherend is insufficient, cutting water may enter between the adherend and the adhesive tape during dicing, contaminating the adherend, and furthermore, separating the adherend into individual pieces. scatter.
  • the thickness of the adhesive layer is increased, low molecular weight components and tackifiers are added to increase adhesive strength, and the elastic modulus of the adhesive layer is lowered. It is possible to think of a method of increasing the adhesive strength by increasing the pressure. However, in this case, the adhesive may be melted by frictional heat generated by the rotation of the blade during dicing, and adhesive scraps may adhere to the adherend by being scraped up.
  • the adhesive is cured by UV irradiation in a state where it has been scraped up, the individualized adherends will be fixed to the adhesive tape, making it difficult to pick up at a low pin height, or even if it can be picked up, In some cases, the adhesive cannot be peeled off at the interface with the adherend, and the adhesive itself is destroyed, leaving the adhesive on the adherend.
  • Patent Document 1 discloses the use of an acrylic polymer and a urethane acrylate oligomer having 3 or more unsaturated bonds.
  • the present invention has been made in view of the above problems, and has high adhesive strength before ultraviolet irradiation, low adhesive strength after ultraviolet irradiation, and adhesive strength even when stored for a long time in a high temperature environment.
  • An object of the present invention is to provide a pressure-sensitive adhesive tape and a processing method with little decrease in the .
  • the present inventors diligently studied to solve the above problems. As a result, the present inventors have found that the above problems can be solved by using an amine compound having a predetermined amount of secondary or higher amine groups, and have completed the present invention.
  • the present invention is as follows.
  • the adhesive layer contains a (meth) acrylic polymer having a carboxyl group, an amine compound having a secondary or higher amine group, and a photopolymerization initiator,
  • the content of the amine compound is 0.1 parts by weight or more with respect to 100 parts by weight of the (meth)acrylic polymer,
  • the adhesive layer has an acid value of 10 mgKOH/g or more, Adhesive tape.
  • the content of the amine compound is 15 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.
  • the adhesive tape according to [1].
  • the amine compound comprises a cyclic amine compound; The adhesive tape according to [1] or [2].
  • the cyclic amine compound comprises an alicyclic amine; The adhesive tape according to [3].
  • the cyclic amine compound comprises 1,4-diazabicyclo[2,2,2]octane or a derivative thereof; The adhesive tape according to [3] or [4].
  • the adhesive layer has an acid value of 100 mgKOH/g or less, [1] The adhesive tape according to any one of [5].
  • the (meth)acrylic polymer has a polymerizable double bond at the end and/or side chain, [1] The adhesive tape according to any one of [6].
  • the (meth) acrylic polymer has a structural unit represented by the following formula (1), [1] The adhesive tape according to any one of [7].
  • R 1 represents an organic group having a polymerizable double bond
  • R 2 represents a single bond or an organic group having 1 to 6 carbon atoms
  • R 3 represents a hydrogen atom or a methyl group.
  • the adhesive layer contains an isocyanate compound, The content of the isocyanate compound is 4.0 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.
  • the adherend is a semiconductor wafer, a semiconductor device, or various semiconductor packages, processing method.
  • an adhesive tape having high adhesive strength before ultraviolet irradiation, low adhesive strength after ultraviolet irradiation, and little decrease in adhesive strength even when stored for a long time in a high temperature environment, and a processing method. can be provided.
  • this embodiment an embodiment of the present invention (hereinafter referred to as “this embodiment”) will be described in detail, but the present invention is not limited to this, and various modifications are possible without departing from the gist thereof. is.
  • (meth)acryl means both methacryl and acryl.
  • monomer means a compound before polymerization
  • structural unit means a repeating unit of a certain monomer in a polymer.
  • the adhesive tape of the present embodiment comprises a substrate and an adhesive layer laminated on at least one surface of the substrate, and the adhesive layer is a (meth)acrylic polymer having a carboxyl group (hereinafter referred to as Also referred to as “(meth)acrylic polymer A”), an amine compound having a secondary or higher amine group (hereinafter also referred to as "amine compound B”), and a photopolymerization initiator, and an amine
  • the content of compound B is 0.1 parts by weight or more relative to 100 parts by weight of (meth)acrylic polymer A, and the adhesive layer has an acid value of 10 mgKOH/g or more.
  • the carboxyl groups derived from the matrix polymer present in the adhesive layer of the adhesive tape can have the function of improving the wettability to the adherend and improving the adhesive strength before UV irradiation.
  • the adhesive tape is stored in a high-temperature environment for a long period of time, reactions such as oxidation, esterification, and condensation of the carboxyl groups proceed, and as a result, the adhesiveness derived from the carboxyl groups decreases over time. It turns out that there is a problem.
  • the (meth)acrylic polymer A having a carboxyl group and the amine compound B having a predetermined amount of a secondary or higher amine group are used in combination to increase the adhesive strength before UV irradiation. is high, the adhesive strength after ultraviolet irradiation is low, and the decrease in adhesive strength can be suppressed even when stored for a long period of time in a high-temperature environment. This is probably because the amine group of the amine compound B is coordinated to the carboxyl group of the (meth)acrylic polymer A, and the reaction of the carboxyl group, which causes the adhesiveness to decrease over time, is suppressed.
  • the mechanism of action is not limited to this.
  • the adhesive tape of this embodiment will be described in detail below.
  • Substrate Materials constituting the substrate are not particularly limited, but examples include polyvinyl chloride, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid-acrylic acid ester film, ethylene-ethyl acrylate copolymer. , polyethylene, polypropylene, propylene-based copolymers, ethylene-acrylic acid copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid-(meth)acrylic acid ester copolymers, etc. is crosslinked with metal ions.
  • the materials constituting the substrate may be used singly or in combination of two or more.
  • the substrate may also be a laminate of multiple layers from such materials.
  • the thickness of the substrate is preferably 10-500 ⁇ m, more preferably 50-200 ⁇ m, and even more preferably 70-150 ⁇ m.
  • the thickness of the substrate means the total thickness when the substrate is composed of a plurality of layers.
  • the base material may be chemically or physically surface-treated, if necessary, on the surface that comes into contact with the adhesive layer.
  • the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high voltage shock exposure, and ionizing radiation treatment.
  • Adhesive layer is a layer laminated on at least one surface of the substrate, and comprises a (meth)acrylic polymer A having a carboxyl group, an amine compound B having a secondary or higher amine group, and photopolymerization. and an initiator, and optionally an isocyanate compound and other components.
  • the acid value of the adhesive layer is 10 mgKOH/g or more, preferably 20 to 120 mgKOH/g, more preferably 25 to 100 mgKOH/g, still more preferably 30 to 80 mgKOH/g.
  • the adhesive layer has an acid value of 10 mgKOH/g or more, the adhesive strength before ultraviolet irradiation is further improved.
  • the adhesive layer has an acid value of 120 mgKOH/g or less, the compatibility of each component is further improved, and the adhesive strength after ultraviolet irradiation tends to be further reduced.
  • chip pick-up efficiency tends to be further improved due to a decrease in adhesive strength after ultraviolet irradiation.
  • the acid value of the adhesive layer can be adjusted by the amount of the (meth)acrylic polymer A and the amine compound B used, which will be described later. Also, the acid value of the adhesive layer can be measured by the method described in Examples.
  • the thickness of the adhesive layer is preferably 1.0 to 250 ⁇ m, more preferably 2.0 to 50 ⁇ m, still more preferably 4.0 to 40 ⁇ m.
  • the thickness of the adhesive layer is 1.0 ⁇ m or more, the adhesive strength is further improved, and the scattering of the semiconductor chips divided by the expansion tends to be suppressed.
  • the thickness of the adhesive layer is 250 ⁇ m or less, the cost tends to be further reduced.
  • the total thickness of the adhesive tape when used as an adhesive tape for semiconductor wafer processing is preferably 60-250 ⁇ m, more preferably 70-200 ⁇ m, and still more preferably 70-180 ⁇ m.
  • Carboxyl Group-Containing (Meth)Acrylic Polymer A carboxyl group-containing (meth)acrylic polymer A contributes to an improvement in adhesive strength before ultraviolet irradiation and a decrease in adhesive strength after ultraviolet irradiation.
  • the (meth)acrylic polymer A may be used singly or in combination of two or more.
  • the adhesive layer of the present embodiment may further contain a (meth)acrylic polymer having no carboxyl group, if necessary.
  • the polymerization form of the (meth)acrylic polymer A is not particularly limited, but examples include homopolymers, random copolymers, block copolymers, and graft copolymers. Moreover, the polymerization form of the (meth)acrylic polymer A is not particularly limited, but examples thereof include a linear polymer, a branched polymer, and a crosslinked polymer. The crosslinked or branched polymer may be one in which part of the polymerizable double bonds of the linear polymer are bonded by aging or the like.
  • the content of (meth)acrylic polymer A is preferably 60 to 99% by mass, more preferably 70 to 99% by mass, and still more preferably 80 to 98% by mass, relative to the total amount of the adhesive layer. be.
  • the content of the (meth)acrylic polymer A is within the above range, there is a tendency that the adhesive strength before ultraviolet irradiation is further improved and the adhesive strength after ultraviolet irradiation is further decreased.
  • Structural units possessed by (meth)acrylic polymer A include structural units derived from (meth)acrylic acid or its derivatives (meth)acrylic monomers, as well as copolymerizable with (meth)acrylic monomers. may contain a structural unit derived from a monomer having a polymerizable double bond.
  • the (meth)acrylic polymer A is not particularly limited as long as it is polymerized with (meth)acrylic monomers as basic units and has carboxyl groups at the ends and/or side chains.
  • the (meth)acrylic polymer A may contain a reactive functional group other than a carboxyl group at its terminal and/or side chain. Examples of such reactive functional groups include, but are not limited to, functional groups containing polymerizable double bonds such as hydroxyl groups, epoxy groups, vinyl groups, and (meth)acryloyl groups.
  • Monomers constituting the structural units of (meth)acrylic polymer A are not particularly limited, but examples include aliphatic group-containing monomers, carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, and sulfonic acid group-containing monomers. , phosphate group-containing monomers. Among these, aliphatic group-containing monomers and carboxyl group-containing monomers are more preferable.
  • aliphatic group-containing monomers include, but are not limited to, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group and hexyl group.
  • heptyl cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, octadecyl, and dodecyl Alkyl (meth)acrylates having linear or branched alkyl groups such as groups. These aliphatic group-containing monomers may be used singly or in combination of two or more.
  • the constituent unit of the aliphatic group-containing monomer is preferably 55 to 95 parts by weight, more preferably 65 to 90 parts by weight, more preferably 75 to 95 parts by weight, relative to the total amount of the (meth)acrylic polymer A. 85 parts by weight.
  • the content of the structural unit of the aliphatic group-containing monomer is within the above range, the adhesive strength before ultraviolet irradiation is further improved, and the adhesive strength after ultraviolet irradiation is further reduced, and can be used for a long time in a high temperature environment. Even in the case of storage, there is a tendency that the decrease in adhesive strength is further suppressed.
  • carboxyl group-containing monomers examples include, but are not limited to, acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. . These carboxyl group-containing monomers may be used singly or in combination of two or more.
  • the structural unit of the carboxyl group-containing monomer is preferably 5 to 45 parts by weight, more preferably 10 to 35 parts by weight, still more preferably 15 to 25 parts by weight, relative to the total amount of the (meth)acrylic polymer A. weight part.
  • the content of the structural unit of the carboxyl group-containing monomer is within the above range, the adhesive strength before ultraviolet irradiation is further improved, and the adhesive strength after ultraviolet irradiation is further reduced, and long-term storage in a high-temperature environment. Even if it does, the decrease in adhesive strength tends to be more suppressed.
  • acid anhydride monomers examples include, but are not limited to, maleic anhydride and itaconic anhydride. These acid anhydride monomers may be used singly or in combination of two or more.
  • hydroxyl group-containing monomers include, but are not limited to, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6 (meth)acrylate. -hydroxyhexyl, 8-hydroxyoctyl (meth)acrylate, 1-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc. be done. These hydroxyl group-containing monomers may be used singly or in combination of two or more.
  • sulfonic acid group-containing monomers include, but are not limited to, styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth) Acrylate, and (meth)acryloyloxynaphthalenesulfonic acid, and the like. These sulfonic acid group-containing monomers may be used singly or in combination of two or more.
  • the phosphate group-containing monomer is not particularly limited, but includes, for example, 2-hydroxyethyl acryloyl phosphate.
  • the (meth)acrylic polymer A preferably has a polymerizable double bond at the end and/or side chain. It is more preferable to have a structural unit with This allows the polymerization initiator to proceed with the polymerization reaction of the (meth)acrylic polymer A by irradiation with ultraviolet rays. As the polymerization reaction of the (meth)acrylic polymer A progresses, the adhesive strength after ultraviolet irradiation tends to decrease, and contamination of adherends tends to be further reduced.
  • R 1 represents an organic group having a polymerizable double bond
  • R 2 represents a single bond or an organic group having 1 to 6 carbon atoms
  • R 3 represents a hydrogen atom or a methyl group.
  • Such groups represented by R 1 include, for example, residues after addition of an epoxy compound having a polymerizable double bond to a carboxyl group.
  • the organic group having 1 to 6 carbon atoms represented by R 2 is not particularly limited, and examples thereof include linear, branched or cyclic alkyl groups, alkyleneoxy groups and the like.
  • R 2 is a single bond
  • R 2 examples include structural units in which an epoxy compound having a polymerizable double bond is added to a structural unit derived from acrylic acid or methacrylic acid.
  • the (meth) before introducing the polymerizable double bond is )
  • the carboxyl group of the structural unit derived from the carboxyl group-containing monomer the anhydrous carboxyl group of the structural unit derived from the acid anhydride monomer, or the hydroxyl group of the structural unit derived from the hydroxyl group-containing monomer of the acrylic polymer A, polymerization and a method of reacting a modifier having a double bond.
  • (meth)acrylic polymer A by reacting (meth)acrylic polymer A with an epoxy compound having a polymerizable double bond as a modifier, the constituent units derived from the carboxyl group-containing monomer are allowed to react with the polymerizable double bond via an ester bond. can be introduced. Further, as another example, the (meth)acrylic polymer A is reacted with an isocyanate compound having a polymerizable double bond as a modifier to obtain a structural unit derived from a carboxyl group-containing monomer via an amide bond. Polymerizable double bonds can be introduced.
  • the modifier is not particularly limited as long as it has a functional group that reacts with the functional group of the (meth)acrylic polymer A and has a polymerizable double bond. and an isocyanate compound having a polymerizable double bond.
  • the content of the structural unit into which a polymerizable double bond is introduced as represented by formula (1) is preferably 2.5 to 25% by mass with respect to the total amount of the (meth)acrylic polymer A, More preferably 5.0 to 20% by mass, still more preferably 7.5 to 15% by mass.
  • the content of the structural unit into which the polymerizable double bond is introduced is preferably 15 to 95 mol%, preferably 30 to 85 mol, relative to the total amount of the structural units constituting the (meth)acrylic polymer A. %, and may be 45 to 80 mol %.
  • the content of the structural unit into which a polymerizable double bond is introduced is 2.5% by mass or more or 15 mol% or more, the adhesive strength after ultraviolet irradiation is further reduced, and the (meth)acrylic polymer is formed by ultraviolet irradiation.
  • the cross-linking reaction of the polymerizable double bond of A progresses sufficiently, and the contact area with the adherend decreases due to curing shrinkage, so that the adhesive force tends to decrease sufficiently.
  • the pick-up performance tends to be further improved because it can be easily peeled off.
  • the content of the structural unit into which a polymerizable double bond is introduced is 25% by mass or less or 95% by mol or less, the number of carboxyl groups is relatively increased, so that the adhesive strength before ultraviolet irradiation is further improved. There is a tendency.
  • the tendency that the adhesive layer cannot withstand the deformation of the adhesive tape due to the push-up of the pin during pick-up and the cracking in the shape of the pin and the resulting adhesive residue are suppressed. It is in.
  • the content of the structural unit having a carboxyl group is preferably 5 to 85 mol%, preferably 15 to 70 mol%, relative to the total amount of the structural units constituting the (meth)acrylic polymer A, It may be 25 to 55 mol %.
  • the (meth)acrylic polymer A preferably has a double bond equivalent weight of 500 to 2500 g/mol, more preferably 800 to 2000 g/mol, and still more preferably 1000 to 1800 g/mol.
  • the (meth)acrylic polymer A has a double bond equivalent of 500 g/mol or more, so the number of carboxyl groups is relatively increased, so the adhesive strength before ultraviolet irradiation tends to be further improved. In addition, since excessive cross-linking can be suppressed, the tendency that the adhesive layer cannot withstand the deformation of the adhesive tape due to the push-up of the pin during pick-up and the cracking in the shape of the pin and the resulting adhesive residue are suppressed. It is in.
  • the double bond equivalent of the (meth)acrylic polymer A is 2500 g/mol or less
  • the crosslinking reaction of the polymerizable double bonds of the (meth)acrylic polymer A sufficiently proceeds by irradiation with ultraviolet rays, and curing.
  • the adhesive strength tends to decrease sufficiently.
  • the pick-up performance tends to be further improved because it can be easily peeled off.
  • unpolymerized monomers remain in the adhesive layer, there is a possibility that they can react with the double bonds of the (meth)acrylic polymer A when irradiated with ultraviolet rays, which tends to further suppress adhesive residue. It is in.
  • the number of carboxyl groups is relatively small, there is a tendency that the decrease in adhesive strength is further suppressed even when stored for a long period of time in a high-temperature environment.
  • the "double bond equivalent" described in this specification is according to "acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter test method of chemical products” (JIS K 0070).
  • the iodine value was measured to determine the amount of double bonds. Specifically, an iodine monochloride solution was added to the sample to add it to the double bond, and excess I was titrated with a sodium thiosulfate solution and obtained by the following formula.
  • A ⁇ (BC) x f x 1.269 ⁇ /S
  • either the polymerization initiation terminal and/or the polymerization termination terminal of the (meth)acrylic polymer A is modified with a compound having a polymerizable double bond. is mentioned.
  • the acid value of the (meth)acrylic polymer A is preferably 10 to 1000 mgKOH/g, 20 to 500 mgKOH/g, 30 to 250 mgKOH/g, and even 30 to 100 mgKOH/g. good.
  • the (meth)acrylic polymer A has an acid value of 10 mgKOH/g or more, the adhesive strength before ultraviolet irradiation tends to be further improved.
  • the acid value of the (meth)acrylic polymer A is 1000 mgKOH/g or less, the compatibility of each component is further improved, and the adhesive strength after ultraviolet irradiation tends to be further reduced.
  • the weight average molecular weight of the (meth)acrylic polymer A is preferably 1.0 ⁇ 10 5 to 2.0 ⁇ 10 6 , more preferably 2.0 ⁇ 10 5 to 1.0 ⁇ 10 6 , more preferably 2.5 ⁇ 10 5 to 8.0 ⁇ 10 5 .
  • the weight average molecular weight of the (meth)acrylic polymer A is 1.0 ⁇ 10 5 or more, the high molecular weight component increases, and the higher the molecular weight, the more one (meth)acrylic polymer A ) There are more chances of polymerization between the acrylic polymer A and the polymerizable double bond, so contamination tends to be further reduced.
  • the (meth)acrylic polymer A has a weight average molecular weight of 2.0 ⁇ 10 6 or less, so that the (meth)acrylic polymer A easily moves, and one (meth)acrylic polymer A becomes the other (meth) Since the chances of polymerization with the acrylic polymer A increase, contamination tends to be further reduced.
  • the smaller the molecular weight the lower the elastic modulus of the pressure-sensitive adhesive, which tends to further improve the pressure-sensitive adhesive strength.
  • contamination due to insufficient ultraviolet curing caused by oxygen inhibition can be avoided.
  • a soft pressure-sensitive adhesive tends to be sufficiently cured and shrunk by irradiation with ultraviolet rays, so that the pressure-sensitive adhesive strength after curing can be sufficiently lowered, and the pick-up property tends to be further improved.
  • the "weight average molecular weight” described in this specification is the molecular weight of a sample obtained by dissolving the (meth)acrylic polymer A in tetrahydrofuran using a gel permeation chromatograph analyzer from the standard polystyrene-equivalent molecular weight calibration curve. is.
  • the glass transition point of the (meth)acrylic polymer A is preferably -80 to 23°C, more preferably -70 to 10°C, still more preferably -60 to 0°C.
  • the glass transition point of (meth)acrylic polymer A can be measured by differential scanning calorimetry (DSC method) based on JIS K7121.
  • the adhesive layer of the present embodiment may further contain a primary amine compound, if necessary, in addition to the amine compound B having a secondary or higher amine group.
  • the amine group of the amine compound B is secondary or higher, preferably secondary or tertiary.
  • the amine group in the amine compound B is a carboxyl group in the (meth)acrylic polymer A compared with the case where only a primary amine compound is used. becomes easier to coordinate to, and the effect of suppressing the decrease in adhesive strength during high-temperature storage appears remarkably.
  • the amine compound B is not particularly limited, but includes, for example, chain amines and cyclic amines. Among these, cyclic amines are preferred.
  • the nitrogen atoms in the amine compound B become more likely to coordinate with the carboxyl groups of the (meth)acrylic polymer, and the tendency to further suppress the decrease in adhesive strength during high-temperature storage. It is in.
  • chain amines include, but are not limited to, dibutylamine, diisobutylamine, dihexylamine, dioctylamine, bis(2-ethylhexyl)amine, diphenylamine, N-methylaniline, N-ethylaniline, tripropylamine, tri Butylamine, triisobutylamine, trihexylamine, trioctylamine, tris(2-ethylhexyl)amine.
  • Cyclic amines include alicyclic amines and aromatic amines.
  • alicyclic amines include, but are not limited to, pyrrolidine, piperidine, morpholine, imidazoline; piperazine, homopiperazine, 1-methylpiperazine, 2-methylpiperazine, 1-ethylpiperazine, 1,4-dimethylpiperazine.
  • Piperazine compounds such as 1-(2-aminoethyl) piperazine; tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate, tetrakis ( 2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacic acid, Bis(2,2,6,6-tetramethyl-4-piperidyl)sebacic acid, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4- Piperidyl methacrylate, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexane-1,6-diamine, bis(1,2,2,6,6-pentamethyl-4-piperidyl) ) piperidyl compounds
  • aromatic amine is not particularly limited, but examples include pyrrole, pyridine, pyrimidine, pyrazine; -ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2, Imidazole compounds such as 3-dihydro-1H-pyrrolo[1,2-a]benzimidazole; 1,3,5-triazine, 1,3,5-triazin-2-amine, 2,4-diamino-6- [2′-methylimid
  • alicyclic amines are preferred, piperidyl compounds and 1,4-diazabicyclo[2,2,2]octane compounds are more preferred, and 1,4-diazabicyclo[2,2,2]octane or derivatives thereof is more preferred, and compounds having a hydroxyl group such as 1,4-diazabicyclo[2,2,2]octane-2-methanol are particularly preferred.
  • amine compound B since the nitrogen atoms protrude outside of the amine compound B, the coordinating ability with respect to the carboxyl group is further improved. Therefore, by using such an amine compound B, there is a tendency to suppress the decrease in adhesive strength during high-temperature storage. In addition, having a hydroxyl group or the like tends to further improve compatibility with other components.
  • the term "derivative" refers to a compound in which a hydrogen atom of a certain compound is substituted with a substituent.
  • substituents include, but are not limited to, halogen groups, hydroxyl groups, amino groups, nitro groups, and carboxyl groups.
  • the number of amino groups possessed by the amine compound B is preferably 1 to 4, more preferably 1 to 3, still more preferably 1 to 2.
  • the number of amino groups is in the above range, the coordinating ability to the carboxyl group is improved, and the decrease in adhesive strength during high-temperature storage tends to be suppressed.
  • the content of the amine compound B is 0.1 parts by weight or more, preferably 0.1 to 15 parts by weight, more preferably 0.5 to 100 parts by weight, relative to 100 parts by weight of the (meth)acrylic polymer A. It is 15.0 parts by weight, more preferably 0.5 to 10.0 parts by weight, and even more preferably 0.5 to 5.0 parts by weight.
  • the content of the amine compound B is 0.1 parts by weight or more, the effect of coordinating the amine compound B to the carboxyl groups of the (meth)acrylic polymer A is sufficiently exhibited, and the adhesive strength is reduced during high-temperature storage. more restrained. Further, when the content of the amine compound B is 15 parts by weight or less, the adhesive strength before ultraviolet irradiation is further improved, and contamination of the adherend by the amine compound B tends to be more suppressed.
  • Photopolymerization Initiator By irradiating the adhesive layer with ultraviolet rays, the photopolymerization initiator generates active species such as radicals, thereby promoting the polymerization of the polymerizable double bonds of the (meth)acrylic polymer A. As a result, the adhesive layer is cured, the viscosity is lowered, and the pick-up property is further improved.
  • photopolymerization initiators include, but are not limited to, alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, thioxanthone photopolymerization initiators, aromatic ketones, and aromatic onium salts. compounds, organic peroxides, thio compounds (thiophenyl group-containing compounds, etc.), ⁇ -aminoalkylphenone compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, carbon halogens Compounds with bonds and alkylamine compounds are included.
  • alkylphenone-based photopolymerization initiators such as acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexylphenyl ketone, and 2,2-dimethoxy-2-phenylacetophenone are preferred.
  • acetophenone acetophenone benzyl ketal, 1-hydroxycyclohexylphenyl ketone, and 2,2-dimethoxy-2-phenylacetophenone
  • polymerization tends to proceed more appropriately.
  • the content of the photopolymerization initiator is preferably 0.5 to 10 parts by weight, more preferably 0.5 to 7.5 parts by weight, based on 100 parts by weight of the (meth)acrylic polymer A, More preferably, it is 0.5 to 5.0 parts by weight.
  • the content of the photopolymerization initiator is 0.5 parts by weight or more, there is a tendency that the adhesive layer can be sufficiently cured even when the illuminance or irradiation amount of ultraviolet rays is low.
  • the content of the photopolymerization initiator is 10 parts by weight or less, the risk of the photopolymerization initiator causing contamination tends to decrease.
  • the adhesive layer may contain an isocyanate compound. This tends to further improve the cohesion of the adhesive layer.
  • the number of isocyanate groups per molecule of the isocyanate compound is preferably 2-6, more preferably 2-4.
  • a plurality of (meth)acrylic polymers A can also be crosslinked by the isocyanate compound, so that the cohesive force of the adhesive layer tends to be further improved.
  • the anchoring property between the base material and the adhesive layer is improved, and more stable adhesive properties tend to be obtained.
  • isocyanate compounds include, but are not limited to, aromatic diisocyanates such as trimethylolpropane-modified tolylene diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, and xylylene diisocyanate; cyclohexyl isocyanate); and aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate.
  • An isocyanate compound may be used individually by 1 type, or may use 2 or more types together.
  • trimethylolpropane-modified tolylene diisocyanate is more preferable.
  • the use of such an isocyanate compound tends to further improve the cohesive strength of the adhesive layer.
  • the content of the isocyanate compound is preferably 4.0 parts by weight or less, more preferably 0.05 to 2.0 parts by weight, and still more preferably 100 parts by weight of the (meth)acrylic polymer A. 0.1 to 1.5 parts by weight.
  • the content of the isocyanate compound is 0.1 parts by weight or more, the cross-linking density of the adhesive layer is further improved, cohesive failure occurring at the time of peeling is further suppressed, and contamination caused by cohesive failure tends to be further suppressed. be.
  • the content of the isocyanate compound is 4.0 parts by weight or less, the crosslink density is further lowered and the elastic modulus is lowered, so that the adhesive strength tends to be further improved.
  • Additives such as tackifiers, cross-linking retarders, antioxidants, metal trapping agents, UV absorbers, plasticizers, metal powders, fillers, and colorants may be added to the adhesive layer as necessary. good.
  • tackifiers include, but are not limited to, petroleum resins, terpene resins, terpene phenol resins, aromatic modified terpene resins, coumarone-indene resins, natural resin rosins, modified rosins, glycerol ester rosins, and pentaerythritol ester rosins. , phenol resins, xylene resins, alicyclic petroleum resins, styrene resins, dicyclopentadiene resins, and the like.
  • the cross-linking retarder is not particularly limited, but examples include ⁇ -diketones such as acetylacetone, hexane-2,4-dione, heptane-2,4-dione, octane-2,4-dione; ⁇ -ketoesters such as ethyl acetate, propyl acetoacetate, butyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate; and benzoylacetone.
  • ⁇ -diketones such as acetylacetone, hexane-2,4-dione, heptane-2,4-dione, octane-2,4-dione
  • ⁇ -ketoesters such as ethyl acetate, propyl acetoacetate, butyl acetoacetate, oc
  • antioxidants include, but are not limited to, methylhydroquinone, hydroquinone, 2,2-methylene-bis(4-methyl-6-tertiarybutylphenol), catechol, hydroquinone monomethyl ether, monotertiarybutylhydroquinone, 2 ,5-ditert-butyl hydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-ditert-butyl-p-benzoquinone, picric acid, citric acid, phenothiazine, tert-butyl catechol, 2-butyl -4-hydroxyanisole, 2,6-ditert-butyl-p-cresol and 4-[[4,6-bis(octylthio)-1,3,5-triazin-2-yl]amino]-2,6- Di-tertiary butyl phenol is mentioned.
  • the adhesive tape of the present embodiment may have a protective film attached to the adhesive layer in order to protect the adhesive layer. Since the protective film is peeled off when the adhesive tape is used, it is preferable that the protective film has excellent peelability.
  • the protective film include, but are not limited to, a film made of a fluororesin having a low surface energy, a polyethylene terephthalate film obtained by treating the surface with a silicone-based release agent, and the like.
  • the adhesive tape of the present embodiment can be suitably used for processing semiconductor wafers, semiconductor devices, or various semiconductor packages.
  • the semiconductor wafer may be a wafer on which an electronic circuit or the like is formed before singulation.
  • a semiconductor device refers to various semiconductor chips or elements containing them after being separated into individual pieces.
  • a semiconductor package refers to a resin for protecting a semiconductor chip and connection terminals that connect the semiconductor chip to the outside. is attached.
  • the method for producing the adhesive tape is not particularly limited, but includes a method of forming an adhesive layer on a substrate.
  • the base material of the adhesive tape of this embodiment can be manufactured according to well-known techniques.
  • the means for molding the base material is not particularly limited, but the various materials mentioned above can be melt-kneaded using conventional melt-kneading or various mixing devices (single- or twin-screw extruders, rolls, Banbury mixers, various kneaders, etc.).
  • the components are mixed by using a T-die method, a calender method, or an inflation method to shape the mixture into a base material.
  • Preferred is a method of forming a film using a T-die method using an extruder with good thickness accuracy.
  • the adhesive layer of the adhesive tape of this embodiment can be manufactured according to known techniques.
  • the means for forming the adhesive layer is not particularly limited, but the above various materials are dissolved in a solvent such as an organic solvent to form a varnish, and this is applied on the protective film by a knife coating method, a roll coating method, or a spray coating method. method, gravure coating method, bar coating method, curtain coating method, or the like, and the solvent is removed to form an adhesive layer.
  • An adhesive tape is produced by laminating this on a base material.
  • aging treatment may be performed after forming the adhesive layer.
  • the formed adhesive layer is stored under a predetermined temperature.
  • the temperature conditions are not particularly limited, but are preferably 30 to 50°C, more preferably 35 to 45°C.
  • Storage time is not particularly limited, but preferably 24 to 150 hours, more preferably 48 to 100 hours.
  • the processing method of the present embodiment includes a bonding step of bonding the adhesive tape and the adherend together, and a dicing step of processing the adherend while the adhesive tape and the adherend are bonded together. and an ultraviolet irradiation step of irradiating the adhesive tape after the dicing step with ultraviolet rays, and processing semiconductor wafers, semiconductor devices, or various semiconductor packages as adherends.
  • the processing method of the present embodiment may have a pick-up step of picking up individualized chips from the adhesive tape after ultraviolet irradiation, if necessary.
  • the lamination step is not particularly limited as long as it is a step of laminating the adhesive layer of the adhesive tape and the adherend.
  • the bonding step may be performed under normal temperature and normal pressure, or may be performed under heating or under reduced pressure as necessary.
  • the singulation method by the dicing process is not particularly limited, and conventionally known methods can be used.
  • a silicon wafer can be cut into semiconductor chips by rotating a dicing blade containing diamond abrasive grains at a high speed using a dicing machine.
  • the ultraviolet irradiation method is not particularly limited, but conventionally known methods can be used.
  • an ultraviolet irradiation device is used to irradiate the adhesive tape in the dicing process with ultraviolet rays.
  • the pick-up method is not particularly limited, but a conventionally known method can be used.
  • an expanding device can be used to stretch the adhesive tape after being irradiated with ultraviolet rays in the surface direction, and the chips can be picked up by a pickup device in a state in which each chip is separated.
  • the carboxyl group of the structural unit derived from acrylic acid in the copolymer obtained as described above was reacted with glycidyl methacrylate to obtain acrylic polymer 1 having a double bond in the side chain.
  • acrylic polymer 1 among 100 mol% of the structural units derived from acrylic acid in the copolymer, 60 mol% of the structural units are structural units reacted with glycidyl methacrylate, and 40 mol% of the structural units. was a structural unit derived from acrylic acid.
  • the carboxyl group of the structural unit derived from acrylic acid in the copolymer obtained as described above was reacted with glycidyl methacrylate to obtain an acrylic polymer 2 having a double bond in the side chain.
  • acrylic polymer 2 among 100 mol% of the structural units derived from acrylic acid in the copolymer, 45 mol% of structural units are structural units reacted with glycidyl methacrylate, and 55 mol% of the structural units. was a structural unit derived from acrylic acid.
  • the carboxyl group of the structural unit derived from acrylic acid in the copolymer obtained as described above was reacted with glycidyl methacrylate to obtain an acrylic polymer 5 having a double bond in the side chain.
  • the acrylic polymer 5 among 100 mol% of the structural units derived from acrylic acid in the copolymer, 80 mol% of the structural units are the structural units reacted with glycidyl methacrylate, and 20 mol% of the structural units. was a structural unit derived from acrylic acid.
  • Example 1 To a solution containing 50 parts by weight of acrylic polymer 1 and 50 parts by weight of acrylic polymer 2, 0.2 parts by weight of trimethylolpropane-modified tolylene diisocyanate (Japan Polyurethane Co., Ltd.: Coronate L-45E) and photopolymerization.
  • Trimethylolpropane-modified tolylene diisocyanate Japan Polyurethane Co., Ltd.: Coronate L-45E
  • Initiator (2,2-dimethoxy-2-phenylacetophenone (manufactured by BASF: Omnirad 651)) 2.1 parts by weight, amine 1 (1,4-diazabicyclo[2,2,2]octane-2-methanol, Tosoh Co., Ltd.: RZETA, about 33% active ingredient, diluted with dipropylene glycol) was added so that the active ingredient was 1.0 part by weight, to prepare an ultraviolet curable resin composition.
  • This resin composition is coated on the release-treated surface of a polyethylene terephthalate protective film that has been subjected to release treatment in advance so that the thickness of the adhesive layer after drying is 10 ⁇ m, and dried at 120° C. for 1 minute. rice field.
  • the surface of the adhesive layer and the corona-treated surface of a polyolefin film (substrate) in which the surface to which the adhesive layer is to be bonded was previously subjected to corona treatment were bonded together to transfer the adhesive to the substrate. This was aged in an atmosphere of 40° C. for 72 hours to obtain an adhesive tape.
  • Example 2 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that acrylic polymer 2 was not used and 100 parts by weight of acrylic polymer 1 was used.
  • Example 3 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that acrylic polymer 1 was not used and 100 parts by weight of acrylic polymer 2 was used.
  • Example 4 Acrylic polymer 1 was not used, 95 parts by weight of acrylic polymer 2, and 5 parts by weight of acrylic polymer 4 (polyacrylic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name polyacrylic acid 5000)) were used. An adhesive tape was produced in the same manner as in Example 1.
  • Example 5 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that the amount of Amine 1 used was 0.5 parts by weight.
  • Example 6 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that the amount of Amine 1 used was 10.0 parts by weight.
  • Example 7 The procedure was the same as in Example 1 except that 10.0 parts by weight of amine 2 (2,2,6,6-tetramethyl-4-piperidyl methacrylate, manufactured by ADEKA: LA-87) was used instead of amine 1. to prepare an adhesive tape.
  • amine 2 (2,2,6,6-tetramethyl-4-piperidyl methacrylate, manufactured by ADEKA: LA-87
  • Example 8 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that 10.0 parts by weight of Amine 3 (dioctylamine, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was used instead of Amine 1.
  • Amine 3 dioctylamine, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.
  • Example 9 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that acrylic polymer 1 was not used, and 90 parts by weight of acrylic polymer 2 and 10 parts by weight of acrylic polymer 4 were used.
  • Example 10 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that acrylic polymer 1 and acrylic polymer 2 were not used, and 100 parts by weight of acrylic polymer 5 was used.
  • Adhesive tape was prepared in the same manner as in Example 1, except that 10.0 parts by weight of primary amine amine 4 (polyoxypropylene diamine, manufactured by HUNTMAN: Jeffamine D-400) was used instead of amine 1. was made.
  • primary amine amine 4 polyoxypropylene diamine, manufactured by HUNTMAN: Jeffamine D-400
  • the acid value [mgKOH/g] of the adhesive layer included in the adhesive tape of each example and each comparative example was measured by the following method. Specifically, first, 1 g of a resin composition for forming an adhesive layer is weighed, and this resin composition is dissolved in 30 g of tetrahydrofuran (THF) in a conical beaker. 3 drops were added. Then, a 0.1N KOH solution (solvent: 2-propanol (IPA)) was added dropwise from a burette, and the neutralization point was calculated.
  • THF tetrahydrofuran
  • IPA 2-propanol
  • the glass transition point of (meth)acrylic polymer A was measured by differential scanning calorimetry (DSC method) based on JIS K7121.
  • the adhesive strength of the adhesive tape of each example and each comparative example was determined by the 180° peel strength measurement method of JIS Z0237 (2009) (Method 1: a test method in which a tape and a sheet are peeled off at 180° against a stainless steel test plate). Measured according to Specifically, the pressure-sensitive adhesive tape was pressed onto the surface-cleaned silicon wafer using a pressure-bonding device (roller mass: 2 kg), and the pressure-sensitive adhesive tape was peeled off from the silicon wafer at 180°. S 0 was measured with a universal tensile tester (Tensilon model number: RTG-1210 manufactured by ORIENTEC) in an environment with a temperature of 23° C. and a humidity of 50%.
  • Method 1 a test method in which a tape and a sheet are peeled off at 180° against a stainless steel test plate.
  • the double bond equivalent is determined by measuring the iodine value in accordance with “Testing methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter of chemical products” (JIS K 0070). A heavy bond amount was determined. Specifically, an iodine monochloride solution was added to the sample to add it to the double bond, and excess I was titrated with a sodium thiosulfate solution and obtained by the following formula.
  • A ⁇ (BC) x f x 1.269 ⁇ /S
  • the adhesive tape of the present invention has industrial applicability as a semiconductor wafer processing tape, particularly as an adhesive tape used in a dicing process.

Abstract

An adhesive tape comprising a substrate and an adhesive layer layered on at least one side of the substrate, wherein the adhesive layer contains a (meth)acrylic polymer having a carboxyl group, an amine compound having a secondary or higher amine group, and a photopolymerization initiator, the amine compound content is at least 0.1 parts by weight per 100 parts by weight of the (meth)acrylic polymer, and the acid value of the adhesive layer is at least 10 mg KOH/g.

Description

粘着テープ及び加工方法Adhesive tape and processing method
　本発明は、粘着テープ及びそれを用いた加工方法に関する。 The present invention relates to an adhesive tape and a processing method using it.
　半導体パッケージや半導体ウエハ（以下、「被着体」ともいう）等を個片化する際には、半導体ウエハ加工用テープを被着体に貼り付けて、ダイシング時に被着体を仮固定する。これにより、個片化時にチップ飛びを防ぐことができる。また、ダイシング後には、半導体ウエハ加工用テープをエキスパンディングし、個片化された被着体は半導体ウエハ加工用テープからピックアップ（剥離）する。 When singulating semiconductor packages, semiconductor wafers (hereinafter also referred to as "adherends"), etc., a semiconductor wafer processing tape is attached to the adherends to temporarily fix the adherends during dicing. As a result, it is possible to prevent chips from flying out during singulation. After dicing, the tape for semiconductor wafer processing is expanded, and the individualized adherends are picked up (peeled off) from the tape for semiconductor wafer processing.
　このような半導体ウエハ加工用テープとしては、紫外線に対し透過性を有するフィルム基材上に紫外線照射により硬化反応する粘着層が塗布された粘着テープが主に用いられている。この紫外線硬化型の加工用テープでは、ダイシング後に紫外線を粘着層に照射して、硬化反応を進行させることで粘着層の粘着力を低下させることができるため、個片化された被着体を容易にピックアップすることができる。 As such a tape for semiconductor wafer processing, an adhesive tape is mainly used in which an adhesive layer that undergoes a curing reaction when irradiated with ultraviolet rays is applied to a film base material that is transparent to ultraviolet rays. In this UV-curable processing tape, the adhesive layer is irradiated with UV rays after dicing, and the curing reaction proceeds to reduce the adhesive strength of the adhesive layer. Can be picked up easily.
　上記ピックアップ時には、粘着テープの被着体と接触していない裏面から、突き上げピンにより個片化した被着体を突き上げて、ピックアップを行う。この際に、被着体への粘着テープの糊残りを低減し、また、低いピンハイトでも高収率でピックアップできることが、高品質な電子部品を効率よく製造する観点から求められる。 At the time of picking up, from the back surface of the adhesive tape that is not in contact with the adherend, the push-up pin pushes up the individualized adherend and picks it up. At this time, from the viewpoint of efficiently manufacturing high-quality electronic components, it is required to reduce the adhesive residue of the adhesive tape on the adherend and to be able to pick up even a low pin height at a high yield.
　しかしながら、被着体への粘着テープ貼り付けの際に被着体に対する粘着剤の濡れ性が良くないと、被着体の段差部等に糊が追従しきれず気泡が入る。そうすると、紫外線照射時に酸素阻害等による粘着剤の硬化不良を引き起こし、被着体に粘着剤が硬化しないまま残留することがある。また、被着体に対する粘着力が不足していると、ダイシング時に切削水が被着体と粘着テープの間に浸入して被着体を汚染したり、さらには個片化した被着体が飛散したりする。 However, when the adhesive tape is attached to the adherend, if the wettability of the adhesive to the adherend is not good, the glue cannot follow the steps of the adherend and air bubbles form. In such a case, the adhesive may be cured poorly due to oxygen inhibition or the like during ultraviolet irradiation, and the adhesive may remain uncured on the adherend. In addition, if the adhesive strength to the adherend is insufficient, cutting water may enter between the adherend and the adhesive tape during dicing, contaminating the adherend, and furthermore, separating the adherend into individual pieces. scatter.
　そこで、被着体に対する粘着剤の濡れ性を補うために粘着層の厚さを増加させたり、低分子量成分や粘着付与剤等を配合して粘着力を上げたり、粘着層の弾性率を低下させて粘着力を上げたりする方法が考えられる。しかしながら、この場合、ダイシング時のブレードの回転により生じる摩擦熱により粘着剤が融解し、掻き上げられることで被着体に粘着剤屑が付着することがある。また粘着剤がかき上げられた状態で紫外線照射により硬化すると、個片化された被着体が粘着テープに固定されてしまい、低ピンハイトでのピックアップが困難になったり、ピックアップできた場合でも、被着体との界面で剥離できず粘着剤自身の破壊が起こり、被着体に粘着剤が残留したりすることがある。 Therefore, in order to compensate for the wettability of the adhesive to the adherend, the thickness of the adhesive layer is increased, low molecular weight components and tackifiers are added to increase adhesive strength, and the elastic modulus of the adhesive layer is lowered. It is possible to think of a method of increasing the adhesive strength by increasing the pressure. However, in this case, the adhesive may be melted by frictional heat generated by the rotation of the blade during dicing, and adhesive scraps may adhere to the adherend by being scraped up. In addition, if the adhesive is cured by UV irradiation in a state where it has been scraped up, the individualized adherends will be fixed to the adhesive tape, making it difficult to pick up at a low pin height, or even if it can be picked up, In some cases, the adhesive cannot be peeled off at the interface with the adherend, and the adhesive itself is destroyed, leaving the adhesive on the adherend.
　このような粘着剤の掻き上げを抑制する方法として、特許文献１のように、アクリル系ポリマーと不飽和結合を３個以上有するウレタンアクリレートオリゴマーとを用いることが開示されている。 As a method for suppressing such scraping of the adhesive, Patent Document 1 discloses the use of an acrylic polymer and a urethane acrylate oligomer having 3 or more unsaturated bonds.
特開２００８－０１３６９２号公報JP 2008-013692 A
　しかしながらこのようにアクリル系ポリマーと不飽和結合を３個以上有するウレタンアクリレートオリゴマーを用いた場合には粘着剤のかき上げは抑制されるものの、紫外線照射後の粘着剤が硬くなりすぎることが分かってきた。紫外線照射後に粘着剤が硬くなりすぎると、ピックアップ時にピンで裏から押し上げたときにテープの変形に硬化後の粘着剤が追従できずに割れる現象が生じる。そして、このような糊割れが生じると、かえって糊残りの原因となる可能性がある。 However, it has been found that when a urethane acrylate oligomer having three or more unsaturated bonds with an acrylic polymer is used in this way, although scraping of the adhesive is suppressed, the adhesive becomes too hard after ultraviolet irradiation. rice field. If the adhesive becomes too hard after UV irradiation, the cured adhesive cannot follow the deformation of the tape when the tape is pushed up from the back with a pin during pick-up, resulting in cracking. If such cracking of the adhesive occurs, it may rather cause an adhesive residue.
　そこで、ポリマーにカルボキシル基を導入し、カルボキシル基の極性を利用することで、被着体との濡れ性を確保することが考えられる。この際、カルボキシル基が多いほど粘着力が上昇し、濡れ性も向上するため、チップ飛びなどのリスクを下げることができる。しかし、本発明者らの検討により、カルボキシル基の含有量が多くなるほど、高温環境で長期間保管した場合に粘着力が徐々に低下し、濡れ性が悪化してチップ飛びなどのリスクが上昇してしまうことが分かってきた。 Therefore, it is conceivable to introduce a carboxyl group into the polymer and use the polarity of the carboxyl group to ensure wettability with the adherend. At this time, the greater the number of carboxyl groups, the higher the adhesive strength and wettability, so the risk of chip flying can be reduced. However, according to the studies of the present inventors, as the content of carboxyl groups increases, the adhesive strength gradually decreases when stored in a high-temperature environment for a long period of time, and the wettability deteriorates, increasing the risk of chip flying. I have come to understand that
　本発明は、上記課題に鑑みてなされたものであり、紫外線照射前の粘着力が高く、かつ紫外線照射後の粘着力が低い上、高温環境下で長期間保管した場合であっても粘着力の低下の少ない粘着テープ及び加工方法を提供することを目的とする。 The present invention has been made in view of the above problems, and has high adhesive strength before ultraviolet irradiation, low adhesive strength after ultraviolet irradiation, and adhesive strength even when stored for a long time in a high temperature environment. An object of the present invention is to provide a pressure-sensitive adhesive tape and a processing method with little decrease in the .
　本発明者らは上記課題を解決するために鋭意検討した。その結果、所定量の２級以上のアミン基を有するアミン化合物を用いることにより、上記課題を解決しうることを見出して、本発明を完成するに至った。 The inventors diligently studied to solve the above problems. As a result, the present inventors have found that the above problems can be solved by using an amine compound having a predetermined amount of secondary or higher amine groups, and have completed the present invention.
　すなわち、本発明は以下のとおりである。
〔１〕
　基材と、該基材の少なくとも一方の面に積層された粘着層と、を備え、
　前記粘着層が、カルボキシル基を有する（メタ）アクリル系ポリマーと、２級以上のアミン基を有するアミン化合物と、光重合開始剤と、を含有し、
　前記アミン化合物の含有量が、前記（メタ）アクリル系ポリマー１００重量部に対して、０．１重量部以上であり、
　前記粘着層の酸価が、１０ｍｇＫＯＨ／ｇ以上である、
　粘着テープ。
〔２〕
　前記アミン化合物の含有量が、前記（メタ）アクリル系ポリマー１００重量部に対して、１５重量部以下である、
　〔１〕に記載の粘着テープ。
〔３〕
　前記アミン化合物が、環状アミン化合物を含む、
　〔１〕又は〔２〕に記載の粘着テープ。
〔４〕
　前記環状アミン化合物が、脂環式アミンを含む、
　〔３〕に記載の粘着テープ。
〔５〕
　前記環状アミン化合物が、１，４－ジアザビシクロ［２，２，２］オクタン又はその誘導体を含む、
　〔３〕又は〔４〕に記載の粘着テープ。
〔６〕
　前記粘着層の酸価が、１００ｍｇＫＯＨ／ｇ以下である、
　〔１〕～〔５〕のいずれか一項に記載の粘着テープ。
〔７〕
　前記（メタ）アクリル系ポリマーが、末端及び／又は側鎖に重合性二重結合を有する、
　〔１〕～〔６〕のいずれか一項に記載の粘着テープ。
〔８〕
　前記（メタ）アクリル系ポリマーが、下記式（１）で表される構成単位を有する、
　〔１〕～〔７〕のいずれか一項に記載の粘着テープ。
Figure JPOXMLDOC01-appb-C000002
（式中、Ｒ１は、重合性二重結合を有する有機基を示し、Ｒ２は、単結合又は炭素数１～６の有機基を示し、Ｒ３は、水素原子又はメチル基を示す。）
〔９〕
　前記粘着層が、イソシアネート化合物を含み、
　該イソシアネート化合物の含有量が、前記（メタ）アクリル系ポリマー１００重量部に対して、４．０重量部以下である、
　〔１〕～〔８〕のいずれか一項に記載の粘着テープ。
〔１０〕
　〔１〕～〔９〕のいずれか一項に記載の粘着テープと、被着体と、を貼り合わせる貼合工程と、
　前記粘着テープと前記被着体とを貼り合わせた状態で、前記被着体を加工するダイシング工程と、
　該ダイシング工程後の粘着テープに紫外線を照射する紫外線照射工程と、を有し、
　前記被着体が、半導体ウエハ、半導体デバイス、又は各種半導体パッケージである、
　加工方法。 That is, the present invention is as follows.
[1]
A base material and an adhesive layer laminated on at least one surface of the base material,
The adhesive layer contains a (meth) acrylic polymer having a carboxyl group, an amine compound having a secondary or higher amine group, and a photopolymerization initiator,
The content of the amine compound is 0.1 parts by weight or more with respect to 100 parts by weight of the (meth)acrylic polymer,
The adhesive layer has an acid value of 10 mgKOH/g or more,
Adhesive tape.
[2]
The content of the amine compound is 15 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.
The adhesive tape according to [1].
[3]
wherein the amine compound comprises a cyclic amine compound;
The adhesive tape according to [1] or [2].
[4]
wherein the cyclic amine compound comprises an alicyclic amine;
The adhesive tape according to [3].
[5]
wherein the cyclic amine compound comprises 1,4-diazabicyclo[2,2,2]octane or a derivative thereof;
The adhesive tape according to [3] or [4].
[6]
The adhesive layer has an acid value of 100 mgKOH/g or less,
[1] The adhesive tape according to any one of [5].
[7]
The (meth)acrylic polymer has a polymerizable double bond at the end and/or side chain,
[1] The adhesive tape according to any one of [6].
[8]
The (meth) acrylic polymer has a structural unit represented by the following formula (1),
[1] The adhesive tape according to any one of [7].
Figure JPOXMLDOC01-appb-C000002
(In the formula, R 1 represents an organic group having a polymerizable double bond, R 2 represents a single bond or an organic group having 1 to 6 carbon atoms, and R 3 represents a hydrogen atom or a methyl group. )
[9]
The adhesive layer contains an isocyanate compound,
The content of the isocyanate compound is 4.0 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.
[1] The adhesive tape according to any one of [8].
[10]
A lamination step of laminating the adhesive tape according to any one of [1] to [9] and an adherend,
A dicing step of processing the adherend while the adhesive tape and the adherend are bonded together;
and an ultraviolet irradiation step of irradiating the adhesive tape after the dicing step with ultraviolet rays,
The adherend is a semiconductor wafer, a semiconductor device, or various semiconductor packages,
processing method.
　本発明によれば、紫外線照射前の粘着力が高く、かつ紫外線照射後の粘着力が低い上、高温環境下で長期間保管した場合であっても粘着力の低下の少ない粘着テープ及び加工方法を提供することができる。 ADVANTAGE OF THE INVENTION According to the present invention, an adhesive tape having high adhesive strength before ultraviolet irradiation, low adhesive strength after ultraviolet irradiation, and little decrease in adhesive strength even when stored for a long time in a high temperature environment, and a processing method. can be provided.
　以下、本発明の実施の形態（以下、「本実施形態」という。）について詳細に説明するが、本発明はこれに限定されるものではなく、その要旨を逸脱しない範囲で様々な変形が可能である。 Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail, but the present invention is not limited to this, and various modifications are possible without departing from the gist thereof. is.
　なお、本実施形態において、「（メタ）アクリル」とは、メタクリルとアクリルの両方を意味するものである。また、「モノマー」とは重合前の化合物を意味し、「構成単位」とは、ポリマー中におけるあるモノマーの繰り返し単位を意味する。 In addition, in the present embodiment, "(meth)acryl" means both methacryl and acryl. Further, "monomer" means a compound before polymerization, and "structural unit" means a repeating unit of a certain monomer in a polymer.
１．粘着テープ
　本実施形態の粘着テープは、基材と、該基材の少なくとも一方の面に積層された粘着層と、を備え、粘着層が、カルボキシル基を有する（メタ）アクリル系ポリマー（以下、「（メタ）アクリル系ポリマーＡ」ともいう。）と、２級以上のアミン基を有するアミン化合物（以下、「アミン化合物Ｂ」ともいう。）と、光重合開始剤と、を含有し、アミン化合物Ｂの含有量が、（メタ）アクリル系ポリマーＡ１００重量部に対して、０．１重量部以上であり、粘着層の酸価が、１０ｍｇＫＯＨ／ｇ以上である。 1. Adhesive Tape The adhesive tape of the present embodiment comprises a substrate and an adhesive layer laminated on at least one surface of the substrate, and the adhesive layer is a (meth)acrylic polymer having a carboxyl group (hereinafter referred to as Also referred to as "(meth)acrylic polymer A"), an amine compound having a secondary or higher amine group (hereinafter also referred to as "amine compound B"), and a photopolymerization initiator, and an amine The content of compound B is 0.1 parts by weight or more relative to 100 parts by weight of (meth)acrylic polymer A, and the adhesive layer has an acid value of 10 mgKOH/g or more.
　粘着テープの粘着層中に存在するマトリクスポリマー由来のカルボキシル基は、被着体に対する濡れ性を向上させ紫外線照射前の粘着力を向上する機能を有しうる。しかしながら、粘着テープを高温環境下で長期間保管すると、カルボキシル基の酸化、エステル化、縮合などの反応が進行し、これにより、カルボキシル基に由来して発揮される粘着性が経時的に低下するという問題があることが分かってきた。 The carboxyl groups derived from the matrix polymer present in the adhesive layer of the adhesive tape can have the function of improving the wettability to the adherend and improving the adhesive strength before UV irradiation. However, if the adhesive tape is stored in a high-temperature environment for a long period of time, reactions such as oxidation, esterification, and condensation of the carboxyl groups proceed, and as a result, the adhesiveness derived from the carboxyl groups decreases over time. It turns out that there is a problem.
　これに対して、本実施形態においては、カルボキシル基を有する（メタ）アクリル系ポリマーＡと所定量の２級以上のアミン基を有するアミン化合物Ｂとを併用することにより、紫外線照射前の粘着力が高く、かつ紫外線照射後の粘着力が低い上、高温環境下で長期間保管した場合であっても粘着力の低下を抑制することができる。これは、（メタ）アクリル系ポリマーＡのカルボキシル基にアミン化合物Ｂのアミン基が配位し、経時的に粘着性が低下する要因となるカルボキシル基の反応が抑制されるためと考えられるが、作用機序はこれに限定されるものではない。以下、本実施形態の粘着テープについて詳説する。 On the other hand, in the present embodiment, the (meth)acrylic polymer A having a carboxyl group and the amine compound B having a predetermined amount of a secondary or higher amine group are used in combination to increase the adhesive strength before UV irradiation. is high, the adhesive strength after ultraviolet irradiation is low, and the decrease in adhesive strength can be suppressed even when stored for a long period of time in a high-temperature environment. This is probably because the amine group of the amine compound B is coordinated to the carboxyl group of the (meth)acrylic polymer A, and the reaction of the carboxyl group, which causes the adhesiveness to decrease over time, is suppressed. The mechanism of action is not limited to this. The adhesive tape of this embodiment will be described in detail below.
１．１．基材
　基材を構成する材料としては、特に制限されないが、例えば、ポリ塩化ビニル、ポリエチレンテレフタレート、エチレン－酢酸ビニル共重合体、エチレン－アクリル酸－アクリル酸エステルフィルム、エチレン－エチルアクリレート共重合体、ポリエチレン、ポリプロピレン、プロピレン系共重合体、エチレン－アクリル酸共重合体、及び、エチレン－（メタ）アクリル酸共重合体やエチレン－（メタ）アクリル酸－（メタ）アクリル酸エステル共重合体等を金属イオンで架橋したアイオノマー樹脂が挙げられる。基材を構成する材料は、これらを１種単独用いても、２種以上を併用してもよい。また、基材は、このような材料から複数の層の積層体であってもよい。 1.1. Substrate Materials constituting the substrate are not particularly limited, but examples include polyvinyl chloride, polyethylene terephthalate, ethylene-vinyl acetate copolymer, ethylene-acrylic acid-acrylic acid ester film, ethylene-ethyl acrylate copolymer. , polyethylene, polypropylene, propylene-based copolymers, ethylene-acrylic acid copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid-(meth)acrylic acid ester copolymers, etc. is crosslinked with metal ions. The materials constituting the substrate may be used singly or in combination of two or more. The substrate may also be a laminate of multiple layers from such materials.
　基材の厚さは、好ましくは１０～５００μｍであり、より好ましくは５０～２００μｍであり、さらに好ましくは７０～１５０μｍである。基材の厚さが上記範囲内であることにより、取扱性がより向上し、コストがより低下する傾向にある。ここで、基材の厚さとは、基材が複数の層から構成される場合にはその総厚を意味する。 The thickness of the substrate is preferably 10-500 μm, more preferably 50-200 μm, and even more preferably 70-150 μm. When the thickness of the base material is within the above range, the handleability tends to be further improved and the cost tends to be further reduced. Here, the thickness of the substrate means the total thickness when the substrate is composed of a plurality of layers.
　基材は、粘着層との密着性を向上させるために、必要に応じて、粘着層が接触する面に化学的又は物理的に表面処理が施されていてもよい。上記表面処理としては、例えば、コロナ処理、クロム酸処理、オゾン暴露、火炎暴露、高圧電撃暴露、及びイオン化放射線処理等が挙げられる。 In order to improve adhesion with the adhesive layer, the base material may be chemically or physically surface-treated, if necessary, on the surface that comes into contact with the adhesive layer. Examples of the surface treatment include corona treatment, chromic acid treatment, ozone exposure, flame exposure, high voltage shock exposure, and ionizing radiation treatment.
１．２．粘着層
　粘着層は、基材の少なくとも一方の面に積層された層であって、カルボキシル基を有する（メタ）アクリル系ポリマーＡと、２級以上のアミン基を有するアミン化合物Ｂと、光重合開始剤と、を含有し、必要に応じて、イソシアネート化合物やその他の成分を含んでいてもよい。 1.2. Adhesive layer The adhesive layer is a layer laminated on at least one surface of the substrate, and comprises a (meth)acrylic polymer A having a carboxyl group, an amine compound B having a secondary or higher amine group, and photopolymerization. and an initiator, and optionally an isocyanate compound and other components.
１．２．１．酸価
　粘着層の酸価は、１０ｍｇＫＯＨ／ｇ以上であり、好ましくは２０～１２０ｍｇＫＯＨ／ｇであり、より好ましくは２５～１００ｍｇＫＯＨ／ｇであり、さらに好ましくは３０～８０ｍｇＫＯＨ／ｇである。粘着層の酸価が１０ｍｇＫＯＨ／ｇ以上であることにより、紫外線照射前の粘着力がより向上する。また、粘着層の酸価が１２０ｍｇＫＯＨ／ｇ以下であることにより、各成分の相溶性がより向上し、また、紫外線照射後の粘着力がより低下する傾向にある。また、紫外線照射後の粘着力の低下により、チップのピックアップ効率がより向上する傾向にある。粘着層の酸価は後述する（メタ）アクリル系ポリマーＡやアミン化合物Ｂの使用量により調整することができる。また、粘着層の酸価は実施例に記載の方法により測定することができる。 1.2.1. Acid Value The acid value of the adhesive layer is 10 mgKOH/g or more, preferably 20 to 120 mgKOH/g, more preferably 25 to 100 mgKOH/g, still more preferably 30 to 80 mgKOH/g. When the adhesive layer has an acid value of 10 mgKOH/g or more, the adhesive strength before ultraviolet irradiation is further improved. Further, when the adhesive layer has an acid value of 120 mgKOH/g or less, the compatibility of each component is further improved, and the adhesive strength after ultraviolet irradiation tends to be further reduced. In addition, chip pick-up efficiency tends to be further improved due to a decrease in adhesive strength after ultraviolet irradiation. The acid value of the adhesive layer can be adjusted by the amount of the (meth)acrylic polymer A and the amine compound B used, which will be described later. Also, the acid value of the adhesive layer can be measured by the method described in Examples.
１．２．２．厚さ
　粘着層の厚さは、好ましくは１．０～２５０μｍであり、より好ましくは２．０～５０μｍであり、さらに好ましくは４．０～４０μｍである。粘着層の厚さが１．０μｍ以上であることによって、粘着力がより向上し、エキスパンドによって分割された半導体のチップの飛散が抑制される傾向にある。また、粘着層の厚さが２５０μｍ以下であることにより、コストがより低下する傾向にある。 1.2.2. Thickness The thickness of the adhesive layer is preferably 1.0 to 250 μm, more preferably 2.0 to 50 μm, still more preferably 4.0 to 40 μm. When the thickness of the adhesive layer is 1.0 μm or more, the adhesive strength is further improved, and the scattering of the semiconductor chips divided by the expansion tends to be suppressed. In addition, when the thickness of the adhesive layer is 250 μm or less, the cost tends to be further reduced.
　なお、半導体ウエハ加工用粘着テープとして使用する際の粘着テープの総厚みは、好ましくは６０～２５０μｍであり、より好ましくは７０～２００μｍであり、さらに好ましくは７０～１８０μｍである。 The total thickness of the adhesive tape when used as an adhesive tape for semiconductor wafer processing is preferably 60-250 μm, more preferably 70-200 μm, and still more preferably 70-180 μm.
１．２．３．　カルボキシル基を有する（メタ）アクリル系ポリマー
　カルボキシル基を有する（メタ）アクリル系ポリマーＡは、紫外線照射前の粘着力の向上、紫外線照射後の粘着力の低下に寄与する。（メタ）アクリル系ポリマーＡは、１種単独で用いてもよいし、２種以上を併用してもよい。なお、本実施形態の粘着層は、カルボキシル基を有する（メタ）アクリル系ポリマーＡに加え、必要に応じて、カルボキシル基を有しない（メタ）アクリル系ポリマーをさらに含んでいてもよい。 1.2.3. Carboxyl Group-Containing (Meth)Acrylic Polymer A carboxyl group-containing (meth)acrylic polymer A contributes to an improvement in adhesive strength before ultraviolet irradiation and a decrease in adhesive strength after ultraviolet irradiation. The (meth)acrylic polymer A may be used singly or in combination of two or more. In addition to the (meth)acrylic polymer A having a carboxyl group, the adhesive layer of the present embodiment may further contain a (meth)acrylic polymer having no carboxyl group, if necessary.
　（メタ）アクリル系ポリマーＡの重合形態は、特に制限されないが、例えば、ホモポリマー、ランダム共重合体、ブロック共重合体、又はグラフト共重合体が挙げられる。また、（メタ）アクリル系ポリマーＡの重合形状は、特に限定されないが、例えば、直鎖状ポリマー、分岐状ポリマー、又は架橋状ポリマーが挙げられる。架橋状又は分岐状を有するポリマーは、直鎖形状を有するポリマーの重合性二重結合の一部がエージング等によって結合したものであってもよい。 The polymerization form of the (meth)acrylic polymer A is not particularly limited, but examples include homopolymers, random copolymers, block copolymers, and graft copolymers. Moreover, the polymerization form of the (meth)acrylic polymer A is not particularly limited, but examples thereof include a linear polymer, a branched polymer, and a crosslinked polymer. The crosslinked or branched polymer may be one in which part of the polymerizable double bonds of the linear polymer are bonded by aging or the like.
　（メタ）アクリル系ポリマーＡの含有量は、粘着層の総量に対して、好ましくは６０～９９質量％であり、より好ましくは７０～９９質量％であり、さらに好ましくは８０～９８質量％である。（メタ）アクリル系ポリマーＡの含有量が上記範囲内であることにより、紫外線照射前の粘着力がより向上、紫外線照射後の粘着力がより低下する傾向にある。 The content of (meth)acrylic polymer A is preferably 60 to 99% by mass, more preferably 70 to 99% by mass, and still more preferably 80 to 98% by mass, relative to the total amount of the adhesive layer. be. When the content of the (meth)acrylic polymer A is within the above range, there is a tendency that the adhesive strength before ultraviolet irradiation is further improved and the adhesive strength after ultraviolet irradiation is further decreased.
１．２．３．１．構成単位
　（メタ）アクリル系ポリマーＡが有する構成単位には、（メタ）アクリル酸又はその誘導体である（メタ）アクリル系モノマーに由来する構成単位の他、（メタ）アクリル系モノマーと共重合可能な重合性二重結合を有するモノマーに由来する構成単位が含まれていてもよい。 1.2.3.1. Structural units Structural units possessed by (meth)acrylic polymer A include structural units derived from (meth)acrylic acid or its derivatives (meth)acrylic monomers, as well as copolymerizable with (meth)acrylic monomers. may contain a structural unit derived from a monomer having a polymerizable double bond.
　（メタ）アクリル系ポリマーＡとしては、（メタ）アクリル系モノマーを基本単位として重合されたものであり、かつ末端及び／又は側鎖にカルボキシル基を有するものであれば特に制限されない。また、（メタ）アクリル系ポリマーＡは末端及び／又は側鎖にカルボキシル基以外の反応性官能基を含んでいてもよい。このような反応性官能基としては、特に限定されないが、例えば、水酸基、エポキシ基、ビニル基、（メタ）アクリロイル基のような重合性二重結合を含む官能基などが挙げられる。 The (meth)acrylic polymer A is not particularly limited as long as it is polymerized with (meth)acrylic monomers as basic units and has carboxyl groups at the ends and/or side chains. In addition, the (meth)acrylic polymer A may contain a reactive functional group other than a carboxyl group at its terminal and/or side chain. Examples of such reactive functional groups include, but are not limited to, functional groups containing polymerizable double bonds such as hydroxyl groups, epoxy groups, vinyl groups, and (meth)acryloyl groups.
　（メタ）アクリル系ポリマーＡの構成単位を構成するモノマーとしては、特に限定されないが、例えば、脂肪族基含有モノマー、カルボキシル基含有モノマー、酸無水物モノマー、ヒドロキシル基含有モノマー、スルホン酸基含有モノマー、リン酸基含有モノマーが挙げられる。このなかでも、脂肪族基含有モノマーとカルボキシル基含有モノマーがより好ましい。 Monomers constituting the structural units of (meth)acrylic polymer A are not particularly limited, but examples include aliphatic group-containing monomers, carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, and sulfonic acid group-containing monomers. , phosphate group-containing monomers. Among these, aliphatic group-containing monomers and carboxyl group-containing monomers are more preferable.
　脂肪族基含有モノマーとしては、特に制限されないが、例えば、メチル基、エチル基、ｎ－プロピル基、イソプロピル基、ｎ－ブチル基、ｔ－ブチル基、イソブチル基、アミル基、イソアミル基、ヘキシル基、ヘプチル基、シクロヘキシル基、２－エチルヘキシル基、オクチル基、イソオクチル基、ノニル基、イソノニル基、デシル基、イソデシル基、ウンデシル基、ラウリル基、トリデシル基、テトラデシル基、ステアリル基、オクタデシル基、及びドデシル基などの直鎖又は分岐のアルキル基を有するアルキル（メタ）アクリレートが挙げられる。これら脂肪族基含有モノマーは、１種単独で用いても、または２種類以上を併用してもよい。 Examples of aliphatic group-containing monomers include, but are not limited to, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group and hexyl group. , heptyl, cyclohexyl, 2-ethylhexyl, octyl, isooctyl, nonyl, isononyl, decyl, isodecyl, undecyl, lauryl, tridecyl, tetradecyl, stearyl, octadecyl, and dodecyl Alkyl (meth)acrylates having linear or branched alkyl groups such as groups. These aliphatic group-containing monomers may be used singly or in combination of two or more.
　脂肪族基含有モノマーが有する構成単位は、（メタ）アクリル系ポリマーＡの総量に対して、好ましくは５５～９５重量部であり、より好ましくは６５～９０重量部であり、さらに好ましくは７５～８５重量部である。脂肪族基含有モノマーが有する構成単位の含有量が上記範囲内であることにより、紫外線照射前の粘着力がより向上し、かつ紫外線照射後の粘着力がより低下し、高温環境下で長期間保管した場合であっても粘着力の低下がより抑制される傾向にある。 The constituent unit of the aliphatic group-containing monomer is preferably 55 to 95 parts by weight, more preferably 65 to 90 parts by weight, more preferably 75 to 95 parts by weight, relative to the total amount of the (meth)acrylic polymer A. 85 parts by weight. When the content of the structural unit of the aliphatic group-containing monomer is within the above range, the adhesive strength before ultraviolet irradiation is further improved, and the adhesive strength after ultraviolet irradiation is further reduced, and can be used for a long time in a high temperature environment. Even in the case of storage, there is a tendency that the decrease in adhesive strength is further suppressed.
　カルボキシル基含有モノマーとしては、特に制限されないが、例えば、アクリル酸、メタクリル酸、カルボキシエチル（メタ）アクリレート、カルボキシペンチル（メタ）アクリレート、イタコン酸、マレイン酸、フマール酸、及びクロトン酸などが挙げられる。これらカルボキシル基含有モノマーは、１種単独で用いても、または２種類以上を併用してもよい。 Examples of carboxyl group-containing monomers include, but are not limited to, acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. . These carboxyl group-containing monomers may be used singly or in combination of two or more.
　カルボキシル基含有モノマーが有する構成単位は、（メタ）アクリル系ポリマーＡの総量に対して、好ましくは５～４５重量部であり、より好ましくは１０～３５重量部であり、さらに好ましくは１５～２５重量部である。カルボキシル基含有モノマーが有する構成単位の含有量が上記範囲内であることにより、紫外線照射前の粘着力がより向上し、かつ紫外線照射後の粘着力がより低下し、高温環境下で長期間保管した場合であっても粘着力の低下がより抑制される傾向にある。 The structural unit of the carboxyl group-containing monomer is preferably 5 to 45 parts by weight, more preferably 10 to 35 parts by weight, still more preferably 15 to 25 parts by weight, relative to the total amount of the (meth)acrylic polymer A. weight part. When the content of the structural unit of the carboxyl group-containing monomer is within the above range, the adhesive strength before ultraviolet irradiation is further improved, and the adhesive strength after ultraviolet irradiation is further reduced, and long-term storage in a high-temperature environment. Even if it does, the decrease in adhesive strength tends to be more suppressed.
　酸無水物モノマーとしては、特に限定されないが、例えば、無水マレイン酸や無水イタコン酸などが挙げられる。これら酸無水物モノマーは、１種単独で用いても、または２種類以上を併用してもよい。 Examples of acid anhydride monomers include, but are not limited to, maleic anhydride and itaconic anhydride. These acid anhydride monomers may be used singly or in combination of two or more.
　ヒドロキシル基含有モノマーとしては、特に限定されないが、例えば、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸２－ヒドロキシプロピル、（メタ）アクリル酸４－ヒドロキシブチル、（メタ）アクリル酸６－ヒドロキシヘキシル、（メタ）アクリル酸８－ヒドロキシオクチル、（メタ）アクリル酸１－ヒドロキシデシル、（メタ）アクリル酸１２－ヒドロキシラウリル、及び（４－ヒドロキシメチルシクロヘキシル）メチル（メタ）アクリレートなどが挙げられる。これらヒドロキシル基含有モノマーは、１種単独で用いても、または２種類以上を併用してもよい。 Examples of hydroxyl group-containing monomers include, but are not limited to, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6 (meth)acrylate. -hydroxyhexyl, 8-hydroxyoctyl (meth)acrylate, 1-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc. be done. These hydroxyl group-containing monomers may be used singly or in combination of two or more.
　スルホン酸基含有モノマーとしては、特に限定されないが、例えば、スチレンスルホン酸、アリルスルホン酸、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸、（メタ）アクリルアミドプロパンスルホン酸、スルホプロピル（メタ）アクリレート、及び（メタ）アクリロイルオキシナフタレンスルホン酸などが挙げられる。これらスルホン酸基含有モノマーは、１種単独で用いても、または２種類以上を併用してもよい。 Examples of sulfonic acid group-containing monomers include, but are not limited to, styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth) Acrylate, and (meth)acryloyloxynaphthalenesulfonic acid, and the like. These sulfonic acid group-containing monomers may be used singly or in combination of two or more.
　リン酸基含有モノマーとしては、特に限定されないが、例えば、２－ヒドロキシエチルアクリロイルホスフェートなどが挙げられる。 The phosphate group-containing monomer is not particularly limited, but includes, for example, 2-hydroxyethyl acryloyl phosphate.
　また、（メタ）アクリル系ポリマーＡは、末端及び／又は側鎖に重合性二重結合を有することが好ましく、側鎖に重合性二重結合を導入した構成単位として下記式（１）で表される構成単位を有することがより好ましい。これにより、紫外線照射によって重合開始剤が（メタ）アクリル系ポリマーＡの重合反応を進行することができる。このような（メタ）アクリル系ポリマーＡの重合反応が進行することで、紫外線照射後の粘着力が低下し、被着体への汚染がより低減する傾向にある。
Figure JPOXMLDOC01-appb-C000003
（式中、Ｒ１は、重合性二重結合を有する有機基を示し、Ｒ２は、単結合又は炭素数１～６の有機基を示し、Ｒ３は、水素原子又はメチル基を示す。） In addition, the (meth)acrylic polymer A preferably has a polymerizable double bond at the end and/or side chain. It is more preferable to have a structural unit with This allows the polymerization initiator to proceed with the polymerization reaction of the (meth)acrylic polymer A by irradiation with ultraviolet rays. As the polymerization reaction of the (meth)acrylic polymer A progresses, the adhesive strength after ultraviolet irradiation tends to decrease, and contamination of adherends tends to be further reduced.
Figure JPOXMLDOC01-appb-C000003
(In the formula, R 1 represents an organic group having a polymerizable double bond, R 2 represents a single bond or an organic group having 1 to 6 carbon atoms, and R 3 represents a hydrogen atom or a methyl group. )
　Ｒ１で表される重合性二重結合を有する有機基としては、特に限定されないが、例えば、－ＣＨ２ＯＣ（＝Ｏ）Ｃ（＝ＣＨ２）ＣＨ３、－ＣＨ２ＯＣ（＝Ｏ）Ｃ（＝ＣＨ２）Ｈ、が挙げられる。このようなＲ１で表される基は、例えば、カルボキシル基に対して重合性二重結合を有するエポキシ化合物が付加した後の残基が挙げられる。 The organic group having a polymerizable double bond represented by R 1 is not particularly limited, but examples include -CH 2 OC(=O)C(=CH 2 )CH 3 and -CH 2 OC(=O). and C(=CH 2 )H. Such groups represented by R 1 include, for example, residues after addition of an epoxy compound having a polymerizable double bond to a carboxyl group.
　Ｒ２で表される炭素数１～６の有機基としては、特に限定されないが、例えば、直鎖、分岐、又は環状のアルキル基、アルキレンオキシ基などが挙げられる。 The organic group having 1 to 6 carbon atoms represented by R 2 is not particularly limited, and examples thereof include linear, branched or cyclic alkyl groups, alkyleneoxy groups and the like.
　Ｒ２が単結合の場合としては、例えば、アクリル酸又はメタクリル酸に由来する構成単位に対して、重合性二重結合を有するエポキシ化合物が付加した構成単位が挙げられる。 Examples of the case where R 2 is a single bond include structural units in which an epoxy compound having a polymerizable double bond is added to a structural unit derived from acrylic acid or methacrylic acid.
　式（１）で表される構成単位のように、（メタ）アクリル系ポリマーＡの側鎖に重合性二重結合を有するようにするには、重合性二重結合を導入する前の（メタ）アクリル系ポリマーＡが有する、カルボキシル基含有モノマー由来の構成単位のカルボキシル基、酸無水物モノマー由来の構成単位の無水カルボキシル基、又はヒドロキシル基含有モノマー由来の構成単位のヒドロキシル基に対して、重合性二重結合を有する変性剤を反応させる方法が挙げられる。 In order to have a polymerizable double bond in the side chain of the (meth)acrylic polymer A like the structural unit represented by the formula (1), the (meth) before introducing the polymerizable double bond is ) For the carboxyl group of the structural unit derived from the carboxyl group-containing monomer, the anhydrous carboxyl group of the structural unit derived from the acid anhydride monomer, or the hydroxyl group of the structural unit derived from the hydroxyl group-containing monomer of the acrylic polymer A, polymerization and a method of reacting a modifier having a double bond.
　例えば、（メタ）アクリル系ポリマーＡに対して、変性剤として重合性二重結合を有するエポキシ化合物を反応させることで、カルボキシル基含有モノマー由来の構成単位にエステル結合を介して重合性二重結合を導入することができる。また、他の例として、（メタ）アクリル系ポリマーＡに対して、変性剤として重合性二重結合を有するイソシアネート化合物を反応させることで、カルボキシル基含有モノマー由来の構成単位にアミド結合を介して重合性二重結合を導入することができる。 For example, by reacting (meth)acrylic polymer A with an epoxy compound having a polymerizable double bond as a modifier, the constituent units derived from the carboxyl group-containing monomer are allowed to react with the polymerizable double bond via an ester bond. can be introduced. Further, as another example, the (meth)acrylic polymer A is reacted with an isocyanate compound having a polymerizable double bond as a modifier to obtain a structural unit derived from a carboxyl group-containing monomer via an amide bond. Polymerizable double bonds can be introduced.
　なお、変性剤としては、（メタ）アクリル系ポリマーＡの有する官能基と反応する官能基を有しかつ重合性二重結合を有するものであれば特に制限されないが、例えば、重合性二重結合を有するエポキシ化合物、重合性二重結合を有するイソシアネート化合物などが挙げられる。 The modifier is not particularly limited as long as it has a functional group that reacts with the functional group of the (meth)acrylic polymer A and has a polymerizable double bond. and an isocyanate compound having a polymerizable double bond.
　式（１）で表されるような重合性二重結合を導入した構成単位の含有量は、（メタ）アクリル系ポリマーＡの総量に対して、好ましくは２．５～２５質量％であり、より好ましくは５．０～２０質量％であり、さらに好ましくは７．５～１５質量％である。 The content of the structural unit into which a polymerizable double bond is introduced as represented by formula (1) is preferably 2.5 to 25% by mass with respect to the total amount of the (meth)acrylic polymer A, More preferably 5.0 to 20% by mass, still more preferably 7.5 to 15% by mass.
　また、重合性二重結合を導入した構成単位の含有量は、（メタ）アクリル系ポリマーＡを構成する構成単の総量に対して、好ましくは、１５～９５モル％であり、３０～８５モル％であり、４５～８０モル％であってもよい。 In addition, the content of the structural unit into which the polymerizable double bond is introduced is preferably 15 to 95 mol%, preferably 30 to 85 mol, relative to the total amount of the structural units constituting the (meth)acrylic polymer A. %, and may be 45 to 80 mol %.
　重合性二重結合を導入した構成単位の含有量が２．５質量％以上又は１５モル％以上であることにより、紫外線照射後の粘着力がより低下し、紫外線照射により（メタ）アクリル系ポリマーＡの重合性二重結合の架橋反応が十分に進行し、硬化収縮により被着体との接触面積が減少することで、粘着力が十分に低下する傾向にある。これにより、容易に剥離ができるため、ピックアップ性能がより向上する傾向にある。また、粘着層に未重合のモノマーが残存するような場合であっても、紫外線照射時に（メタ）アクリル系ポリマーＡの二重結合と反応できる可能性もあり、糊残りがより抑制される傾向にある。さらに、相対的にカルボキシル基が少なくなるため、高温環境下で長期間保管した場合であっても粘着力の低下がより抑制される傾向にある。 When the content of the structural unit into which a polymerizable double bond is introduced is 2.5% by mass or more or 15 mol% or more, the adhesive strength after ultraviolet irradiation is further reduced, and the (meth)acrylic polymer is formed by ultraviolet irradiation. The cross-linking reaction of the polymerizable double bond of A progresses sufficiently, and the contact area with the adherend decreases due to curing shrinkage, so that the adhesive force tends to decrease sufficiently. As a result, the pick-up performance tends to be further improved because it can be easily peeled off. In addition, even if unpolymerized monomers remain in the adhesive layer, there is a possibility that they can react with the double bonds of the (meth)acrylic polymer A when irradiated with ultraviolet rays, which tends to further suppress adhesive residue. It is in. Furthermore, since the number of carboxyl groups is relatively small, there is a tendency that the decrease in adhesive strength is further suppressed even when stored for a long period of time in a high-temperature environment.
　また、重合性二重結合を導入した構成単位の含有量が２５質量％以下又は９５モル％以下であることにより、相対的にカルボキシル基が多くなるため、紫外線照射前の粘着力がより向上する傾向にある。また、過度な架橋を抑制できるため、ピックアップ時のピンの突き上げによる粘着テープの変形に粘着層が耐えられずピンの形に割れたり、またそれにより糊残りが生じたりすることが抑制される傾向にある。 In addition, when the content of the structural unit into which a polymerizable double bond is introduced is 25% by mass or less or 95% by mol or less, the number of carboxyl groups is relatively increased, so that the adhesive strength before ultraviolet irradiation is further improved. There is a tendency. In addition, since excessive cross-linking can be suppressed, the tendency that the adhesive layer cannot withstand the deformation of the adhesive tape due to the push-up of the pin during pick-up and the cracking in the shape of the pin and the resulting adhesive residue are suppressed. It is in.
　また、カルボキシル基を有する構成単位の含有量は、（メタ）アクリル系ポリマーＡを構成する構成単の総量に対して、好ましくは、５～８５モル％であり、１５～７０モル％であり、２５～５５モル％であってもよい。 Further, the content of the structural unit having a carboxyl group is preferably 5 to 85 mol%, preferably 15 to 70 mol%, relative to the total amount of the structural units constituting the (meth)acrylic polymer A, It may be 25 to 55 mol %.
　また、（メタ）アクリル系ポリマーＡの二重結合当量は、好ましくは５００～２５００ｇ／ｍｏｌであり、より好ましくは８００～２０００ｇ／ｍｏｌであり、さらに好ましくは１０００～１８００ｇ／ｍｏｌである。 In addition, the (meth)acrylic polymer A preferably has a double bond equivalent weight of 500 to 2500 g/mol, more preferably 800 to 2000 g/mol, and still more preferably 1000 to 1800 g/mol.
　（メタ）アクリル系ポリマーＡの二重結合当量が５００ｇ／ｍｏｌ以上であることにより、相対的にカルボキシル基が多くなるため、紫外線照射前の粘着力がより向上する傾向にある。また、過度な架橋を抑制できるため、ピックアップ時のピンの突き上げによる粘着テープの変形に粘着層が耐えられずピンの形に割れたり、またそれにより糊残りが生じたりすることが抑制される傾向にある。 When the (meth)acrylic polymer A has a double bond equivalent of 500 g/mol or more, the number of carboxyl groups is relatively increased, so the adhesive strength before ultraviolet irradiation tends to be further improved. In addition, since excessive cross-linking can be suppressed, the tendency that the adhesive layer cannot withstand the deformation of the adhesive tape due to the push-up of the pin during pick-up and the cracking in the shape of the pin and the resulting adhesive residue are suppressed. It is in.
　また、（メタ）アクリル系ポリマーＡの二重結合当量が２５００ｇ／ｍｏｌ以下であることにより、紫外線照射により（メタ）アクリル系ポリマーＡの重合性二重結合の架橋反応が十分に進行し、硬化収縮により被着体との接触面積が減少することで、粘着力が十分に低下する傾向にある。これにより、容易に剥離ができるため、ピックアップ性能がより向上する傾向にある。また、粘着層に未重合のモノマーが残存するような場合であっても、紫外線照射時に（メタ）アクリル系ポリマーＡの二重結合と反応できる可能性もあり、糊残りがより抑制される傾向にある。さらに、相対的にカルボキシル基が少なくなるため、高温環境下で長期間保管した場合であっても粘着力の低下がより抑制される傾向にある。 Further, when the double bond equivalent of the (meth)acrylic polymer A is 2500 g/mol or less, the crosslinking reaction of the polymerizable double bonds of the (meth)acrylic polymer A sufficiently proceeds by irradiation with ultraviolet rays, and curing. As the contact area with the adherend decreases due to shrinkage, the adhesive strength tends to decrease sufficiently. As a result, the pick-up performance tends to be further improved because it can be easily peeled off. In addition, even if unpolymerized monomers remain in the adhesive layer, there is a possibility that they can react with the double bonds of the (meth)acrylic polymer A when irradiated with ultraviolet rays, which tends to further suppress adhesive residue. It is in. Furthermore, since the number of carboxyl groups is relatively small, there is a tendency that the decrease in adhesive strength is further suppressed even when stored for a long period of time in a high-temperature environment.
　本明細書で記載する「二重結合当量」は、「化学製品の酸価，けん化価，エステル価，よう素価，水酸基価及び不けん化物の試験方法」（ＪＩＳ　Ｋ　００７０）」に沿って、よう素価を測定し二重結合量を求めたものである。具体的には、試料に一塩化よう素溶液を添加し二重結合に付加させ、過剰のＩをチオ硫酸ナトリウム溶液で滴定し、以下の式で求めた。
　Ａ＝｛（Ｂ－Ｃ）×ｆ×１．２６９｝／Ｓ
　Ａ：よう素価
　Ｂ：空試験に用いたチオ硫酸ナトリウム溶液の量（ｍＬ）
　Ｃ：滴定に用いたチオ硫酸ナトリウム溶液の量（ｍＬ）
　ｆ：チオ硫酸ナトリウム溶液のファクター
　Ｓ：試料の質量（ｇ） The "double bond equivalent" described in this specification is according to "acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter test method of chemical products" (JIS K 0070). , the iodine value was measured to determine the amount of double bonds. Specifically, an iodine monochloride solution was added to the sample to add it to the double bond, and excess I was titrated with a sodium thiosulfate solution and obtained by the following formula.
A = {(BC) x f x 1.269}/S
A: Iodine value B: Amount of sodium thiosulfate solution used for blank test (mL)
C: Amount of sodium thiosulfate solution used for titration (mL)
f: factor of sodium thiosulfate solution S: mass of sample (g)
　なお、末端に重合性二重結合を有するようにするには、（メタ）アクリル系ポリマーＡの重合開始末端及び／又は重合停止末端のいずれかを重合性二重結合を有する化合物で変性する方法が挙げられる。 In order to have a polymerizable double bond at the terminal, either the polymerization initiation terminal and/or the polymerization termination terminal of the (meth)acrylic polymer A is modified with a compound having a polymerizable double bond. is mentioned.
　また、（メタ）アクリル系ポリマーＡの酸価は、好ましくは、１０～１０００ｍｇＫＯＨ／ｇであり、２０～５００ｍｇＫＯＨ／ｇであり、３０～２５０ｍｇＫＯＨ／ｇであり、３０～１００ｍｇＫＯＨ／ｇであってもよい。（メタ）アクリル系ポリマーＡの酸価が１０ｍｇＫＯＨ／ｇ以上であることにより、紫外線照射前の粘着力がより向上する傾向にある。また、（メタ）アクリル系ポリマーＡの酸価が１０００ｍｇＫＯＨ／ｇ以下であることにより、各成分の相溶性がより向上し、また、紫外線照射後の粘着力がより低下する傾向にある。 Further, the acid value of the (meth)acrylic polymer A is preferably 10 to 1000 mgKOH/g, 20 to 500 mgKOH/g, 30 to 250 mgKOH/g, and even 30 to 100 mgKOH/g. good. When the (meth)acrylic polymer A has an acid value of 10 mgKOH/g or more, the adhesive strength before ultraviolet irradiation tends to be further improved. Further, when the acid value of the (meth)acrylic polymer A is 1000 mgKOH/g or less, the compatibility of each component is further improved, and the adhesive strength after ultraviolet irradiation tends to be further reduced.
１．２．３．２．重量平均分子量
　（メタ）アクリル系ポリマーＡの重量平均分子量は、好ましくは１．０×１０５～２．０×１０６であり、より好ましくは２．０×１０５～１．０×１０６、さらに好ましくは、２．５×１０５～８．０×１０５である。 1.2.3.2. Weight Average Molecular Weight The weight average molecular weight of the (meth)acrylic polymer A is preferably 1.0×10 5 to 2.0×10 6 , more preferably 2.0×10 5 to 1.0×10 6 , more preferably 2.5×10 5 to 8.0×10 5 .
　（メタ）アクリル系ポリマーＡの重量平均分子量が１．０×１０５以上であることにより、高分子量成分が多くなるほか、分子量が高いほど１つの（メタ）アクリル系ポリマーＡが他の（メタ）アクリル系ポリマーＡと重合性二重結合で重合する機会が多くなるため、汚染がより低減する傾向にある。 When the weight average molecular weight of the (meth)acrylic polymer A is 1.0 × 10 5 or more, the high molecular weight component increases, and the higher the molecular weight, the more one (meth)acrylic polymer A ) There are more chances of polymerization between the acrylic polymer A and the polymerizable double bond, so contamination tends to be further reduced.
　（メタ）アクリル系ポリマーＡの重量平均分子量が２．０×１０６以下であることにより、（メタ）アクリル系ポリマーＡが動きやすく、１つの（メタ）アクリル系ポリマーＡが他の（メタ）アクリル系ポリマーＡと重合する機会が多くなるため、汚染がより低減する傾向にある。また、分子量が小さいほど粘着剤の弾性率が低くなり、粘着力がより向上する傾向にある。また、被着体への追従性が良くなり被着体の段差にも追従できるため、酸素阻害が原因の紫外線硬化不良による汚染を避けることができる。さらに柔らかい粘着剤は紫外線照射により十分に硬化収縮しやすいため、硬化後の粘着力を十分に下げることができるため、ピックアップ性もより向上する傾向にある。 The (meth)acrylic polymer A has a weight average molecular weight of 2.0×10 6 or less, so that the (meth)acrylic polymer A easily moves, and one (meth)acrylic polymer A becomes the other (meth) Since the chances of polymerization with the acrylic polymer A increase, contamination tends to be further reduced. In addition, the smaller the molecular weight, the lower the elastic modulus of the pressure-sensitive adhesive, which tends to further improve the pressure-sensitive adhesive strength. In addition, since the followability to the adherend is improved and the adherend can follow steps, contamination due to insufficient ultraviolet curing caused by oxygen inhibition can be avoided. Further, a soft pressure-sensitive adhesive tends to be sufficiently cured and shrunk by irradiation with ultraviolet rays, so that the pressure-sensitive adhesive strength after curing can be sufficiently lowered, and the pick-up property tends to be further improved.
　本明細書で記載する「重量平均分子量」は、（メタ）アクリル系ポリマーＡをテトラヒドロフランに溶解したサンプルを、ゲル浸透クロマトグラフ分析装置を用いて、スタンダードポリスチレン換算の分子量の検量線から測定した分子量である。 The "weight average molecular weight" described in this specification is the molecular weight of a sample obtained by dissolving the (meth)acrylic polymer A in tetrahydrofuran using a gel permeation chromatograph analyzer from the standard polystyrene-equivalent molecular weight calibration curve. is.
１．２．３．３．ガラス転移点
　（メタ）アクリル系ポリマーＡのガラス転移点は、好ましくは－８０～２３℃であり、より好ましくは－７０～１０℃であり、さらに好ましくは－６０～０℃である。（メタ）アクリル系ポリマーＡのガラス転移点が－８０℃以上であることにより、汚染がより低減する傾向にある。また、（メタ）アクリル系ポリマーＡのガラス転移点が２３℃以下であることにより、被着物に対する接着性がより向上する傾向にある。（メタ）アクリル系ポリマーＡのガラス転移点は、ＪＩＳ　Ｋ７１２１に基づいて、示差走査熱量測定法（ＤＳＣ法）により測定できる。 1.2.3.3. Glass transition point The glass transition point of the (meth)acrylic polymer A is preferably -80 to 23°C, more preferably -70 to 10°C, still more preferably -60 to 0°C. When the (meth)acrylic polymer A has a glass transition point of −80° C. or higher, contamination tends to be further reduced. Moreover, since the (meth)acrylic polymer A has a glass transition point of 23° C. or less, the adhesiveness to the adherend tends to be further improved. The glass transition point of (meth)acrylic polymer A can be measured by differential scanning calorimetry (DSC method) based on JIS K7121.
１．２．４．　２級以上のアミン基を有するアミン化合物
　２級以上のアミン基を有するアミン化合物Ｂは、（メタ）アクリル系ポリマーＡ由来のカルボキシル基に対して配位することで、カルボキシル基の酸化、エステル化、縮合などの反応を抑制することができ、経時的な粘着性の低下を抑制できる。なお、本実施形態の粘着層は、２級以上のアミン基を有するアミン化合物Ｂに加え、必要に応じて、１級のアミン化合物をさらに含んでいてもよい。 1.2.4. Amine compound having a secondary or higher amine group The amine compound B having a secondary or higher amine group coordinates to the carboxyl group derived from the (meth)acrylic polymer A, thereby oxidizing and esterifying the carboxyl group. , condensation, etc., can be suppressed, and a decrease in adhesiveness over time can be suppressed. The adhesive layer of the present embodiment may further contain a primary amine compound, if necessary, in addition to the amine compound B having a secondary or higher amine group.
　アミン化合物Ｂが有するアミン基は、２級以上であり、好ましくは２～３級である。２級以上のアミン基を有するアミン化合物Ｂを用いることにより、１級のアミン化合物のみを用いた場合と比較して、アミン化合物Ｂ中のアミン基が（メタ）アクリル系ポリマーＡ中のカルボキシル基に配位しやすくなり、高温保管時の粘着力低下抑制効果が顕著に表れる。 The amine group of the amine compound B is secondary or higher, preferably secondary or tertiary. By using the amine compound B having a secondary or higher amine group, the amine group in the amine compound B is a carboxyl group in the (meth)acrylic polymer A compared with the case where only a primary amine compound is used. becomes easier to coordinate to, and the effect of suppressing the decrease in adhesive strength during high-temperature storage appears remarkably.
　アミン化合物Ｂとしては、特に限定されないが、例えば、鎖状アミンや環状アミンが挙げられる。このなかでも、環状アミンが好ましい。このようなアミン化合物Ｂを用いることにより、アミン化合物Ｂ中の窒素原子がより（メタ）アクリル系ポリマーのカルボキシル基に配位しやすくなり、高温保管時の粘着力の低下がより抑制される傾向にある。 The amine compound B is not particularly limited, but includes, for example, chain amines and cyclic amines. Among these, cyclic amines are preferred. By using such an amine compound B, the nitrogen atoms in the amine compound B become more likely to coordinate with the carboxyl groups of the (meth)acrylic polymer, and the tendency to further suppress the decrease in adhesive strength during high-temperature storage. It is in.
　鎖状アミンとしては、特に限定されないが、例えば、ジブチルアミン、ジイソブチルアミン、ジヘキシルアミン、ジオクチルアミン、ビス（２－エチルヘキシル）アミン、ジフェニルアミン、Ｎ－メチルアニリン、Ｎ－エチルアニリン、トリプロピルアミン、トリブチルアミン、トリイソブチルアミン、トリヘキシルアミン、トリオクチルアミン、トリス（２－エチルヘキシル）アミンが挙げられる。 Examples of chain amines include, but are not limited to, dibutylamine, diisobutylamine, dihexylamine, dioctylamine, bis(2-ethylhexyl)amine, diphenylamine, N-methylaniline, N-ethylaniline, tripropylamine, tri Butylamine, triisobutylamine, trihexylamine, trioctylamine, tris(2-ethylhexyl)amine.
　環状アミンとしては、脂環族アミンと芳香族アミンが挙げられる。脂環族アミンとしては、特に限定されないが、例えば、ピロリジン、ピぺリジン、モルホリン、イミダゾリン；ピペラジン、ホモピペラジン、１－メチルピペラジン、２－メチルピペラジン、１－エチルピペラジン、１，４－ジメチルピペラジン、１－（２－アミノエチル）ピペラジン等のピペラジン系化合物；テトラキス（１，２，２，６，６－ペンタメチル－４－ピペリジル）ブタン－１，２，３，４－テトラカルボキシレート、テトラキス（２，２，６，６－テトラメチル－４－ピペリジル）ブタン－１，２，３，４－テトラカルボキシレート、ビス（１，２，２，６，６－ペンタメチル－４－ピペリジル）セバシン酸、ビス（２，２，６，６－テトラメチル－４－ピペリジル）セバシン酸、１，２，２，６，６－ペンタメチル－４－ピペリジルメタクリレート、２，２，６，６－テトラメチル－４－ピペリジルメタクリレート、Ｎ，Ｎ’－ビス（２，２，６，６－テトラメチル－４－ピペリジル）ヘキサン－１，６－ジアミン、ビス（１，２，２，６，６－ペンタメチル－４－ピペリジル）ブチル（３，５－ジ－ｔｅｒｔ－ブチル－４－ヒドロキシベンジル）マロン酸などのピペリジル系化合物；１，４－ジアザビシクロ［２，２，２］オクタン、２－メチル－１，４－ジアザビシクロ［２，２，２］オクタン、１，４－ジアザビシクロ［２，２，２］オクタン－２－オール、２－クロロ－１，４－ジアザビシクロ［２，２，２］オクタン、１，４－ジアザビシクロ［２，２，２］オクタン－２－メタノール、１，４－ジアザビシクロ［２，２，２］オクタン－２，５－ジメタノール、１，４－ジアザビシクロ［２，２，２］オクタン－２－カルボン酸、１，４－ジアザビシクロ［２，２，２］オクタン－２－カルボン酸メチル、１，４－ジアザビシクロ［２，２，２］オクタ－２－エン、１，４－ジアザビシクロ［２，２，２］オクタ－２，５－ジエン、１，４－ジアザビシクロ［２，２，２］オクタ－イルメチル－２－プロペノエートなど１，４－ジアザビシクロ［２，２，２］オクタン系化合物；１，５－ジアザビシクロ［３，２，２］ノナン、１，４－ジアザビシクロ［３，２，２］ノナン、１，８－ジアザビシクロ［５，４，０］－７－ウンデセン、１，５－ジアザビシクロ［４，３，０］－５－ノネンが挙げられる。 Cyclic amines include alicyclic amines and aromatic amines. Examples of alicyclic amines include, but are not limited to, pyrrolidine, piperidine, morpholine, imidazoline; piperazine, homopiperazine, 1-methylpiperazine, 2-methylpiperazine, 1-ethylpiperazine, 1,4-dimethylpiperazine. , Piperazine compounds such as 1-(2-aminoethyl) piperazine; tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-tetracarboxylate, tetrakis ( 2,2,6,6-tetramethyl-4-piperidyl)butane-1,2,3,4-tetracarboxylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacic acid, Bis(2,2,6,6-tetramethyl-4-piperidyl)sebacic acid, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4- Piperidyl methacrylate, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexane-1,6-diamine, bis(1,2,2,6,6-pentamethyl-4-piperidyl) ) piperidyl compounds such as butyl (3,5-di-tert-butyl-4-hydroxybenzyl)malonic acid; 1,4-diazabicyclo[2,2,2]octane, 2-methyl-1,4-diazabicyclo[ 2,2,2] octane, 1,4-diazabicyclo[2,2,2]octan-2-ol, 2-chloro-1,4-diazabicyclo[2,2,2]octane, 1,4-diazabicyclo[ 2,2,2]octane-2-methanol, 1,4-diazabicyclo[2,2,2]octane-2,5-dimethanol, 1,4-diazabicyclo[2,2,2]octane-2-carvone acid, methyl 1,4-diazabicyclo[2,2,2]octane-2-carboxylate, 1,4-diazabicyclo[2,2,2]oct-2-ene, 1,4-diazabicyclo[2,2, 2] Octa-2,5-diene, 1,4-diazabicyclo[2,2,2]octane compounds such as 1,4-diazabicyclo[2,2,2]oct-ylmethyl-2-propenoate; diazabicyclo[3,2,2]nonane, 1,4-diazabicyclo[3,2,2]nonane, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3 ,0]-5-nonene.
　また、芳香族アミンとしては、特に限定されないが、例えば、ピロール、ピリジン、ピリミジン、ピラジン；イミダゾール、２－メチルイミダゾール、２－ウンデシルイミダゾール、２－ヘプタデシルイミダゾール、１，２－ジメチルイミダゾール、２－エチル－４－メチルイミダゾール、２－フェニルイミダゾール、２－フェニル－４－メチルイミダゾール、１－ベンジル－２－フェニルイミダゾール、１－シアノエチル－２－メチルイミダゾール、１－シアノエチル－２－ウンデシルイミダゾール、１－シアノエチル－２－エチル－４－メチルイミダゾール、１－シアノエチル－２－フェニルイミダゾール、２－フェニル－４，５－ジヒドロキシメチルイミダゾール、２－フェニル－４－メチル－５－ヒドロキシメチルイミダゾール、２，３－ジヒドロ－１Ｈ－ピロロ［１，２－ａ］ベンズイミダゾールなどのイミダゾール系化合物；１，３，５－トリアジン、１，３，５－トリアジン－２－アミン、２，４－ジアミノ－６－［２’－メチルイミダゾリル－（１’）］エチル－ｓ－トリアジン、２，４－ジアミノ－６－［２’－ウンデシルイミダゾリル－（１’）］エチル－ｓ－トリアジン、２，４－ジアミノ－６－［２’－エチル－４’－メチルイミダゾリル－（１’）］エチル－ｓ－トリアジンなどのトリアジン系化合物が挙げられる。 In addition, the aromatic amine is not particularly limited, but examples include pyrrole, pyridine, pyrimidine, pyrazine; -ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2, Imidazole compounds such as 3-dihydro-1H-pyrrolo[1,2-a]benzimidazole; 1,3,5-triazine, 1,3,5-triazin-2-amine, 2,4-diamino-6- [2′-methylimidazolyl-(1′)]ethyl-s-triazine, 2,4-diamino-6-[2′-undecylimidazolyl-(1′)]ethyl-s-triazine, 2,4-diamino -6-[2'-ethyl-4'-methylimidazolyl-(1')]ethyl-s-triazine and other triazine compounds.
　このなかでも、脂環式アミンが好ましく、ピペリジル系化合物や１，４－ジアザビシクロ［２，２，２］オクタン系化合物がより好ましく、１，４－ジアザビシクロ［２，２，２］オクタン又はその誘導体がさらに好ましく、１，４－ジアザビシクロ［２，２，２］オクタン－２－メタノールなどの水酸基を有する化合物が特に好ましい。このようなアミン化合物Ｂは、窒素原子がアミン化合物Ｂの外側に張り出すため、カルボキシル基に対する配位性がより向上する。そのため、このようなアミン化合物Ｂを用いることにより、高温保管時の粘着力の低下より抑制される傾向にある。また、水酸基などを有することにより、他成分との相溶性がより向上する傾向にある。 Among these, alicyclic amines are preferred, piperidyl compounds and 1,4-diazabicyclo[2,2,2]octane compounds are more preferred, and 1,4-diazabicyclo[2,2,2]octane or derivatives thereof is more preferred, and compounds having a hydroxyl group such as 1,4-diazabicyclo[2,2,2]octane-2-methanol are particularly preferred. In such amine compound B, since the nitrogen atoms protrude outside of the amine compound B, the coordinating ability with respect to the carboxyl group is further improved. Therefore, by using such an amine compound B, there is a tendency to suppress the decrease in adhesive strength during high-temperature storage. In addition, having a hydroxyl group or the like tends to further improve compatibility with other components.
　なお、本実施形態において「誘導体」とは、ある化合物の水素原子が置換基に置換されている化合物をいう。置換基としては、特に限定されないが、例えば、ハロゲン基、ヒドロキシル基、アミノ基、ニトロ基、カルボキシル基が挙げられる。 In the present embodiment, the term "derivative" refers to a compound in which a hydrogen atom of a certain compound is substituted with a substituent. Examples of substituents include, but are not limited to, halogen groups, hydroxyl groups, amino groups, nitro groups, and carboxyl groups.
　アミン化合物Ｂが有するアミノ基の数は、好ましくは１～４個であり、より好ましくは１～３個であり、さらに好ましくは１～２個である。アミノ基の数が上記範囲である低分子であることにより、カルボキシル基に対する配位性がより向上し、高温保管時の粘着力の低下より抑制される傾向にある。 The number of amino groups possessed by the amine compound B is preferably 1 to 4, more preferably 1 to 3, still more preferably 1 to 2. When the number of amino groups is in the above range, the coordinating ability to the carboxyl group is improved, and the decrease in adhesive strength during high-temperature storage tends to be suppressed.
　アミン化合物Ｂの含有量は、（メタ）アクリル系ポリマーＡ　１００重量部に対して、０．１重量部以上であり、好ましくは０．１～１５重量部であり、より好ましくは０．５～１５．０重量部であり、さらに好ましくは０．５～１０．０重量部であり、よりさらに好ましくは０．５～５．０重量部である。アミン化合物Ｂの含有量が０．１重量部以上であることにより、（メタ）アクリル系ポリマーＡのカルボキシル基へのアミン化合物Ｂの配位効果が十分発揮され、高温保管時の粘着力低下がより抑制される。また、アミン化合物Ｂの含有量が１５重量部以下であることにより、紫外線照射前の粘着力がより向上するほか、アミン化合物Ｂによる被着体への汚染がより抑制される傾向にある。 The content of the amine compound B is 0.1 parts by weight or more, preferably 0.1 to 15 parts by weight, more preferably 0.5 to 100 parts by weight, relative to 100 parts by weight of the (meth)acrylic polymer A. It is 15.0 parts by weight, more preferably 0.5 to 10.0 parts by weight, and even more preferably 0.5 to 5.0 parts by weight. When the content of the amine compound B is 0.1 parts by weight or more, the effect of coordinating the amine compound B to the carboxyl groups of the (meth)acrylic polymer A is sufficiently exhibited, and the adhesive strength is reduced during high-temperature storage. more restrained. Further, when the content of the amine compound B is 15 parts by weight or less, the adhesive strength before ultraviolet irradiation is further improved, and contamination of the adherend by the amine compound B tends to be more suppressed.
１．２．５．　光重合開始剤
　粘着層に紫外線照射をすることで、光重合開始剤がラジカルなどの活性種を発生させ、それにより（メタ）アクリル系ポリマーＡの重合性二重結合の重合が進行する。これにより粘着層が硬化し、粘度が低下して、ピックアップ性がより向上する。 1.2.5. Photopolymerization Initiator By irradiating the adhesive layer with ultraviolet rays, the photopolymerization initiator generates active species such as radicals, thereby promoting the polymerization of the polymerizable double bonds of the (meth)acrylic polymer A. As a result, the adhesive layer is cured, the viscosity is lowered, and the pick-up property is further improved.
　このような光重合開始剤としては、特に限定されないが、例えば、アルキルフェノン系光重合開始剤、アシルホスフィンオキサイド系光重合開始剤、チオキサントン系光重合開始剤、芳香族ケトン類、芳香族オニウム塩化合物、有機過酸化物、チオ化合物（チオフェニル基含有化合物など）、α－アミノアルキルフェノン化合物、ヘキサアリールビイミダゾール化合物、ケトオキシムエステル化合物、ボレート化合物、アジニウム化合物、メタロセン化合物、活性エステル化合物、炭素ハロゲン結合を有する化合物、及びアルキルアミン化合物が挙げられる。 Examples of such photopolymerization initiators include, but are not limited to, alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, thioxanthone photopolymerization initiators, aromatic ketones, and aromatic onium salts. compounds, organic peroxides, thio compounds (thiophenyl group-containing compounds, etc.), α-aminoalkylphenone compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, carbon halogens Compounds with bonds and alkylamine compounds are included.
　このなかでも、アセトフェノン、アセトフェノンベンジルケタール、１－ヒドロキシシクロヘキシルフェニルケトン、２，２－ジメトキシ－２－フェニルアセトフェノンなどのアルキルフェノン系光重合開始剤が好ましい。このような光重合開始剤を用いることにより、重合がより適切に進行する傾向にある。 Among these, alkylphenone-based photopolymerization initiators such as acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexylphenyl ketone, and 2,2-dimethoxy-2-phenylacetophenone are preferred. By using such a photopolymerization initiator, polymerization tends to proceed more appropriately.
　光重合開始剤の含有量は、（メタ）アクリル系ポリマーＡ　１００重量部に対して、好ましくは０．５～１０重量部であり、より好ましくは０．５～７．５重量部であり、さらに好ましくは０．５～５．０重量部である。光重合開始剤の含有量が０．５重量部以上であることにより、紫外線の照度又は照射量が低い場合であっても、十分に粘着層を硬化させることができる傾向にある。また、光重合開始剤の含有量が１０重量部以下であることにより、光重合開始剤が汚染の原因となるリスクが低下する傾向にある。 The content of the photopolymerization initiator is preferably 0.5 to 10 parts by weight, more preferably 0.5 to 7.5 parts by weight, based on 100 parts by weight of the (meth)acrylic polymer A, More preferably, it is 0.5 to 5.0 parts by weight. When the content of the photopolymerization initiator is 0.5 parts by weight or more, there is a tendency that the adhesive layer can be sufficiently cured even when the illuminance or irradiation amount of ultraviolet rays is low. Moreover, when the content of the photopolymerization initiator is 10 parts by weight or less, the risk of the photopolymerization initiator causing contamination tends to decrease.
１．２．６．イソシアネート化合物
　粘着層は、イソシアネート化合物を含んでいてもよい。これにより、粘着層の凝集力がより向上する傾向にある。イソシアネート化合物一分子当たりのイソシアネート基の数は、好ましくは２～６個であり、より好ましくは２～４個である。このようなイソシアネート化合物を用いることにより、複数の（メタ）アクリル系ポリマーＡ間をイソシアネート化合物によっても架橋することができるため、粘着層の凝集力がより向上する傾向にある。また、基材と粘着層とのアンカー性も向上し、より安定した粘着特性が得られる傾向にある。 1.2.6. Isocyanate Compound The adhesive layer may contain an isocyanate compound. This tends to further improve the cohesion of the adhesive layer. The number of isocyanate groups per molecule of the isocyanate compound is preferably 2-6, more preferably 2-4. By using such an isocyanate compound, a plurality of (meth)acrylic polymers A can also be crosslinked by the isocyanate compound, so that the cohesive force of the adhesive layer tends to be further improved. In addition, the anchoring property between the base material and the adhesive layer is improved, and more stable adhesive properties tend to be obtained.
　このようなイソシアネート化合物としては、特に限定されないが、例えば、トリメチロールプロパン変性トリレンジイソシアネート、トリレンジイソシアネート、４，４－ジフェニルメタンジイソシアネート、キシリレンジイソシアネート等の芳香族ジイソシアネート；イソホロンジイソシアネート、メチレンビス（４－シクロヘキシルイソシアネート）等の脂環族ジイソシアネート；ヘキサメチレンジイソシアネート、トリメチルヘキサメチレンジイソシアネート等の脂肪族ジイソシアネートが挙げられる。イソシアネート化合物は１種単独で用いても、２種以上を併用してもよい。 Examples of such isocyanate compounds include, but are not limited to, aromatic diisocyanates such as trimethylolpropane-modified tolylene diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, and xylylene diisocyanate; cyclohexyl isocyanate); and aliphatic diisocyanates such as hexamethylene diisocyanate and trimethylhexamethylene diisocyanate. An isocyanate compound may be used individually by 1 type, or may use 2 or more types together.
　このなかでも、トリメチロールプロパン変性トリレンジイソシアネートがより好ましい。このようなイソシアネート化合物を用いることにより、粘着層の凝集力がより向上する傾向にある。 Among these, trimethylolpropane-modified tolylene diisocyanate is more preferable. The use of such an isocyanate compound tends to further improve the cohesive strength of the adhesive layer.
　イソシアネート化合物の含有量は、（メタ）アクリル系ポリマーＡ　１００重量部に対して、好ましくは４．０重量部以下であり、より好ましくは０．０５～２．０重量部であり、さらに好ましくは０．１～１．５重量部である。イソシアネート化合物の含有量が０．１重量部以上であることにより、粘着層の架橋密度がより向上し、剥離時に生じる凝集破壊がより抑制され、凝集破壊に起因する汚染がより抑制される傾向にある。また、イソシアネート化合物の含有量が４．０重量部以下であることにより、架橋密度がより低下し、弾性率が低くなるため、粘着力がより向上する傾向にある。 The content of the isocyanate compound is preferably 4.0 parts by weight or less, more preferably 0.05 to 2.0 parts by weight, and still more preferably 100 parts by weight of the (meth)acrylic polymer A. 0.1 to 1.5 parts by weight. When the content of the isocyanate compound is 0.1 parts by weight or more, the cross-linking density of the adhesive layer is further improved, cohesive failure occurring at the time of peeling is further suppressed, and contamination caused by cohesive failure tends to be further suppressed. be. In addition, when the content of the isocyanate compound is 4.0 parts by weight or less, the crosslink density is further lowered and the elastic modulus is lowered, so that the adhesive strength tends to be further improved.
１．２．７．その他の成分
　粘着層は、必要に応じて、粘着付与剤、架橋遅延剤、酸化防止剤、金属トラップ剤、紫外線吸収剤、可塑剤、金属粉、フィラー、着色剤などの添加剤を加えてもよい。 1.2.7. Other components Additives such as tackifiers, cross-linking retarders, antioxidants, metal trapping agents, UV absorbers, plasticizers, metal powders, fillers, and colorants may be added to the adhesive layer as necessary. good.
　粘着付与剤としては、特に制限されないが、例えば、石油系樹脂、テルペン樹脂、テルペンフェノール樹脂、芳香族変性テルペン樹脂、クマロンーインデン樹脂、天然樹脂ロジン、変性ロジン、グリセリンエステルロジン、ペンタエリスリトールエステルロジン、フェノール樹脂、キシレン樹脂、脂環族系石油樹脂、スチレン系樹脂、ジシクロペンタジエン樹脂等が挙げられる。 Examples of tackifiers include, but are not limited to, petroleum resins, terpene resins, terpene phenol resins, aromatic modified terpene resins, coumarone-indene resins, natural resin rosins, modified rosins, glycerol ester rosins, and pentaerythritol ester rosins. , phenol resins, xylene resins, alicyclic petroleum resins, styrene resins, dicyclopentadiene resins, and the like.
　架橋遅延剤としては、特に制限されないが、例えば、アセチルアセトン、ヘキサン－２，４－ジオン、ヘプタン－２，４－ジオン、オクタン－２，４－ジオン等のβ－ジケトン類；アセト酢酸メチル、アセト酢酸エチル、アセト酢酸プロピル、アセト酢酸ブチル、アセト酢酸オクチル、アセト酢酸オレイル、アセト酢酸ラウリル、アセト酢酸ステアリル等のβ－ケトエステル類；ベンゾイルアセトン等が挙げられる。 The cross-linking retarder is not particularly limited, but examples include β-diketones such as acetylacetone, hexane-2,4-dione, heptane-2,4-dione, octane-2,4-dione; β-ketoesters such as ethyl acetate, propyl acetoacetate, butyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate, and stearyl acetoacetate; and benzoylacetone.
　酸化防止剤としては、特に制限されないが、例えば、メチルハイドロキノン、ハイドロキノン、２，２－メチレン－ビス（４－メチル－６－ターシャリーブチルフェノール）、カテコール、ハイドロキノンモノメチルエーテル、モノターシャリーブチルハイドロキノン、２，５－ジターシャリーブチルハイドロキノン、ｐ－ベンゾキノン、２，５－ジフェニル－ｐ－ベンゾキノン、２，５－ジターシャリーブチル－ｐ－ベンゾキノン、ピクリン酸、クエン酸、フェノチアジン、ターシャリーブチルカテコール、２－ブチル－４－ヒドロキシアニソール、２，６－ジターシャリーブチル－ｐ－クレゾール及び４－［［４，６－ビス（オクチルチオ）－１，３，５－トリアジン－２－イル］アミノ］－２，６－ジターシャリーブチルフェノールが挙げられる。 Examples of antioxidants include, but are not limited to, methylhydroquinone, hydroquinone, 2,2-methylene-bis(4-methyl-6-tertiarybutylphenol), catechol, hydroquinone monomethyl ether, monotertiarybutylhydroquinone, 2 ,5-ditert-butyl hydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-ditert-butyl-p-benzoquinone, picric acid, citric acid, phenothiazine, tert-butyl catechol, 2-butyl -4-hydroxyanisole, 2,6-ditert-butyl-p-cresol and 4-[[4,6-bis(octylthio)-1,3,5-triazin-2-yl]amino]-2,6- Di-tertiary butyl phenol is mentioned.
１．３．保護フィルム
　本実施形態の粘着テープは、粘着層を保護するため、粘着層に貼り合わせられた保護フィルムを有していてもよい。保護フィルムは、粘着テープの使用時に剥離されるため、剥離性に優れるものが好ましい。保護フィルムとしては、特に制限されないが、例えば、フッ素樹脂からなる表面エネルギーの低いフィルム、ポリエチレンテレフタレートの表面をシリコーン系剥離剤で処理したフィルム等が挙げられる。 1.3. Protective Film The adhesive tape of the present embodiment may have a protective film attached to the adhesive layer in order to protect the adhesive layer. Since the protective film is peeled off when the adhesive tape is used, it is preferable that the protective film has excellent peelability. Examples of the protective film include, but are not limited to, a film made of a fluororesin having a low surface energy, a polyethylene terephthalate film obtained by treating the surface with a silicone-based release agent, and the like.
１．４．用途
　本実施形態の粘着テープは、半導体ウエハ、半導体デバイス、又は各種半導体パッケージの加工用途に好適に用いることができる。半導体ウエハは、電子回路等が形成された個片化前のものであってもよい。また、半導体デバイスは、個片化された後の各種半導体チップあるいはそれを含む素子をいい、半導体パッケージとは、半導体チップにそれを保護するための樹脂と半導体チップと外部とを接続する接続端子を付したものをいう。 1.4. Applications The adhesive tape of the present embodiment can be suitably used for processing semiconductor wafers, semiconductor devices, or various semiconductor packages. The semiconductor wafer may be a wafer on which an electronic circuit or the like is formed before singulation. A semiconductor device refers to various semiconductor chips or elements containing them after being separated into individual pieces. A semiconductor package refers to a resin for protecting a semiconductor chip and connection terminals that connect the semiconductor chip to the outside. is attached.
２．粘着テープの製造方法
　粘着テープの製造方法としては、特に制限されないが、基材上に粘着層を形成する方法が挙げられる。 2. Method for Producing Adhesive Tape The method for producing the adhesive tape is not particularly limited, but includes a method of forming an adhesive layer on a substrate.
　本実施形態の粘着テープの基材は、周知の技術に沿って製造することができる。基材を成形する手段は、特に限定されるものでないが、上記各種材料を慣用の溶融混練等や各種混合装置（１軸又は２軸押出機、ロール、バンバリーミキサー、各種ニーダー等）を使用して各成分が均一に分散するように混合し、当該混合物をＴダイ法、カレンダー法、インフレ法で基材に成形する。好ましくは、厚さ精度がよい押出機によるＴダイ法を用い製膜する方法である。 The base material of the adhesive tape of this embodiment can be manufactured according to well-known techniques. The means for molding the base material is not particularly limited, but the various materials mentioned above can be melt-kneaded using conventional melt-kneading or various mixing devices (single- or twin-screw extruders, rolls, Banbury mixers, various kneaders, etc.). The components are mixed by using a T-die method, a calender method, or an inflation method to shape the mixture into a base material. Preferred is a method of forming a film using a T-die method using an extruder with good thickness accuracy.
　本実施形態の粘着テープの粘着層は、周知の技術に沿って製造することができる。粘着層を成形する手段は、特に限定されるものでないが、上記各種材料を有機溶剤等の溶媒に溶解させてワニス化し、これを保護フィルムの上に、ナイフコート法、ロールコート法、スプレーコート法、グラビアコート法、バーコート法、又はカーテンコート法等によって塗工し、溶媒を除去することによって粘着層を形成する。これを基材上に貼り合せることによって、粘着テープを作製する。 The adhesive layer of the adhesive tape of this embodiment can be manufactured according to known techniques. The means for forming the adhesive layer is not particularly limited, but the above various materials are dissolved in a solvent such as an organic solvent to form a varnish, and this is applied on the protective film by a knife coating method, a roll coating method, or a spray coating method. method, gravure coating method, bar coating method, curtain coating method, or the like, and the solvent is removed to form an adhesive layer. An adhesive tape is produced by laminating this on a base material.
　本実施形態においては、粘着層を形成後に、エージング処理をしてもよい。エージング処理では、形成した粘着層を所定の温度下で保管する。温度条件は、特に制限されないが、好ましくは３０～５０℃であり、より好ましくは３５～４５℃である。また、保管時間は、特に制限されないが、好ましくは２４～１５０時間であり、より好ましくは４８～１００時間である。このエージング処理を行うことで、粘着層の粘着力や、硬化特性が変化する。 In this embodiment, aging treatment may be performed after forming the adhesive layer. In the aging treatment, the formed adhesive layer is stored under a predetermined temperature. The temperature conditions are not particularly limited, but are preferably 30 to 50°C, more preferably 35 to 45°C. Storage time is not particularly limited, but preferably 24 to 150 hours, more preferably 48 to 100 hours. By performing this aging treatment, the adhesive strength and curing properties of the adhesive layer change.
３．加工方法
　本実施形態の加工方法は、上記粘着テープと、被着体と、を貼り合わせる貼合工程と、粘着テープと被着体とを貼り合わせた状態で、被着体を加工するダイシング工程と、ダイシング工程後の粘着テープに紫外線を照射する紫外線照射工程を有し、被着体として半導体ウエハ、半導体デバイス、又は各種半導体パッケージを加工する方法である。また、本実施形態の加工方法は、必要に応じて、紫外線照射後の粘着テープから、個片化したチップをピックアップするピックアップ工程を有していてもよい。 3. Processing method The processing method of the present embodiment includes a bonding step of bonding the adhesive tape and the adherend together, and a dicing step of processing the adherend while the adhesive tape and the adherend are bonded together. and an ultraviolet irradiation step of irradiating the adhesive tape after the dicing step with ultraviolet rays, and processing semiconductor wafers, semiconductor devices, or various semiconductor packages as adherends. Moreover, the processing method of the present embodiment may have a pick-up step of picking up individualized chips from the adhesive tape after ultraviolet irradiation, if necessary.
　貼合工程は、粘着テープの粘着層と被着体とを貼り合わせる工程であれば、特に限定されない。貼り合わせ工程は常温常圧下において行ってもよいし、必要に応じて、加温下や減圧下において行ってもよい。 The lamination step is not particularly limited as long as it is a step of laminating the adhesive layer of the adhesive tape and the adherend. The bonding step may be performed under normal temperature and normal pressure, or may be performed under heating or under reduced pressure as necessary.
　ダイシング工程による個片化方法は、特に制限されず従来公知の方法を用いることができる。例えば、ダイシング装置を用いダイヤモンド砥粒を含有するダイシングブレ―ドを高速回転させることにより、シリコンウエハを半導体チップに切断することができる。 The singulation method by the dicing process is not particularly limited, and conventionally known methods can be used. For example, a silicon wafer can be cut into semiconductor chips by rotating a dicing blade containing diamond abrasive grains at a high speed using a dicing machine.
　紫外線照射方法は、特に制限されないが、従来公知の方法を用いることができる。例えば、紫外線照射装置を用いて、ダイシング工程の粘着テープに紫外線を照射する。 The ultraviolet irradiation method is not particularly limited, but conventionally known methods can be used. For example, an ultraviolet irradiation device is used to irradiate the adhesive tape in the dicing process with ultraviolet rays.
　その後、ピックアップ方法は、特に制限されないが、従来公知の方法を用いることができる。例えば、エキスパンディング装置を用いて、紫外線照射後の粘着テープを面方向に引き伸ばし、各チップを分離させた状態でピックアップ装置によりチップをピックアップすることができる。 After that, the pick-up method is not particularly limited, but a conventionally known method can be used. For example, an expanding device can be used to stretch the adhesive tape after being irradiated with ultraviolet rays in the surface direction, and the chips can be picked up by a pickup device in a state in which each chip is separated.
　以下、本発明を実施例及び比較例を用いてより具体的に説明するが、本発明はこれらに限定されるものではない。 The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to these.
（合成例１：アクリル系ポリマー１）
　アクリル酸２－エチルヘキシル８２重量部と、アクリル酸１８重量部と、重合開始剤（アゾビスイソブチロニトリル）０．０５重量部とを酢酸エチル中で、６５℃で、２４時間、共重合させて、共重合体を得た。 (Synthesis Example 1: Acrylic Polymer 1)
82 parts by weight of 2-ethylhexyl acrylate, 18 parts by weight of acrylic acid, and 0.05 parts by weight of a polymerization initiator (azobisisobutyronitrile) were copolymerized in ethyl acetate at 65° C. for 24 hours. to obtain a copolymer.
　上記のようにして得られた共重合体中のアクリル酸に由来する構成単位のカルボキシル基に、メタクリル酸グリシジルを反応させて、側鎖に二重結合を有するアクリル系ポリマー１を得た。なお、アクリル系ポリマー１は、上記共重合体のアクリル酸に由来する構成単位１００モル％のうち、６０モル％の構成単位がメタクリル酸グリシジルと反応した構成単位であり、４０モル％の構成単位がアクリル酸に由来する構成単位であった。 The carboxyl group of the structural unit derived from acrylic acid in the copolymer obtained as described above was reacted with glycidyl methacrylate to obtain acrylic polymer 1 having a double bond in the side chain. In the acrylic polymer 1, among 100 mol% of the structural units derived from acrylic acid in the copolymer, 60 mol% of the structural units are structural units reacted with glycidyl methacrylate, and 40 mol% of the structural units. was a structural unit derived from acrylic acid.
（合成例２：アクリル系ポリマー２）
　アクリル酸２－エチルヘキシル８２重量部と、アクリル酸１８重量部と、重合開始剤（アゾビスイソブチロニトリル）０．０５重量部とを酢酸エチル中で、６５℃で、２４時間、共重合させて、共重合体を得た。 (Synthesis Example 2: Acrylic polymer 2)
82 parts by weight of 2-ethylhexyl acrylate, 18 parts by weight of acrylic acid, and 0.05 parts by weight of a polymerization initiator (azobisisobutyronitrile) were copolymerized in ethyl acetate at 65° C. for 24 hours. to obtain a copolymer.
　上記のようにして得られた共重合体中のアクリル酸に由来する構成単位のカルボキシル基に、メタクリル酸グリシジルを反応させて、側鎖に二重結合を有するアクリル系ポリマー２を得た。なお、アクリル系ポリマー２は、上記共重合体のアクリル酸に由来する構成単位１００モル％のうち、４５モル％の構成単位がメタクリル酸グリシジルと反応した構成単位であり、５５モル％の構成単位がアクリル酸に由来する構成単位であった。 The carboxyl group of the structural unit derived from acrylic acid in the copolymer obtained as described above was reacted with glycidyl methacrylate to obtain an acrylic polymer 2 having a double bond in the side chain. In acrylic polymer 2, among 100 mol% of the structural units derived from acrylic acid in the copolymer, 45 mol% of structural units are structural units reacted with glycidyl methacrylate, and 55 mol% of the structural units. was a structural unit derived from acrylic acid.
（合成例３：アクリルポリマー５の合成）
　アクリル酸２－エチルヘキシル８２重量部と、アクリル酸１８重量部と、重合開始剤（アゾビスイソブチロニトリル）０．０５重量部とを酢酸エチル中で、６５℃で、２４時間、共重合させて、共重合体を得た。 (Synthesis Example 3: Synthesis of acrylic polymer 5)
82 parts by weight of 2-ethylhexyl acrylate, 18 parts by weight of acrylic acid, and 0.05 parts by weight of a polymerization initiator (azobisisobutyronitrile) were copolymerized in ethyl acetate at 65° C. for 24 hours. to obtain a copolymer.
　上記のようにして得られた共重合体中のアクリル酸に由来する構成単位のカルボキシル基に、メタクリル酸グリシジルを反応させて、側鎖に二重結合を有するアクリル系ポリマー５を得た。なお、アクリル系ポリマー５は、上記共重合体のアクリル酸に由来する構成単位１００モル％のうち、８０モル％の構成単位がメタクリル酸グリシジルと反応した構成単位であり、２０モル％の構成単位がアクリル酸に由来する構成単位であった。 The carboxyl group of the structural unit derived from acrylic acid in the copolymer obtained as described above was reacted with glycidyl methacrylate to obtain an acrylic polymer 5 having a double bond in the side chain. In the acrylic polymer 5, among 100 mol% of the structural units derived from acrylic acid in the copolymer, 80 mol% of the structural units are the structural units reacted with glycidyl methacrylate, and 20 mol% of the structural units. was a structural unit derived from acrylic acid.
（実施例１）
　アクリル系ポリマー１を５０重量部と、アクリル系ポリマー２を５０重量部含む溶液に、トリメチロールプロパン変性トリレンジイソシアネート（日本ポリウレタン株式会社：コロネートＬ－４５Ｅ）を０．２重量部と、光重合開始剤（２，２－ジメトキシ－２－フェニルアセトフェノン（ＢＡＳＦ社製：Ｏｍｎｉｒａｄ　６５１））２．１重量部と、アミン１（１，４－ジアザビシクロ［２，２，２］オクタン－２－メタノール、東ソー製：ＲＺＥＴＡ、有効成分約３３％、ジプロピレングリコールで希釈）を有効成分が１．０重量部となるように加えて、紫外線硬化型の樹脂組成物を調製した。 (Example 1)
To a solution containing 50 parts by weight of acrylic polymer 1 and 50 parts by weight of acrylic polymer 2, 0.2 parts by weight of trimethylolpropane-modified tolylene diisocyanate (Japan Polyurethane Co., Ltd.: Coronate L-45E) and photopolymerization. Initiator (2,2-dimethoxy-2-phenylacetophenone (manufactured by BASF: Omnirad 651)) 2.1 parts by weight, amine 1 (1,4-diazabicyclo[2,2,2]octane-2-methanol, Tosoh Co., Ltd.: RZETA, about 33% active ingredient, diluted with dipropylene glycol) was added so that the active ingredient was 1.0 part by weight, to prepare an ultraviolet curable resin composition.
　この樹脂組成物を、予め離型処理の施されたポリエチレンテレフタレート保護フィルムの離型処理面上に、乾燥後の粘着層の厚みが１０μｍとなるように塗工し、１２０℃で１分間乾燥させた。その後、粘着層の表面と、予め粘着層が張り合わされる表面にコロナ処理が施されたポリオレフィンフィルム（基材）のコロナ処理面と、を貼り合わせて基材に粘着剤を転写させた。これを４０℃の雰囲気下で７２時間エージングし、粘着テープを得た。 This resin composition is coated on the release-treated surface of a polyethylene terephthalate protective film that has been subjected to release treatment in advance so that the thickness of the adhesive layer after drying is 10 μm, and dried at 120° C. for 1 minute. rice field. After that, the surface of the adhesive layer and the corona-treated surface of a polyolefin film (substrate) in which the surface to which the adhesive layer is to be bonded was previously subjected to corona treatment were bonded together to transfer the adhesive to the substrate. This was aged in an atmosphere of 40° C. for 72 hours to obtain an adhesive tape.
（実施例２）
　アクリル系ポリマー２を用いず、アクリル系ポリマー１を１００重量部用いたこと以外は実施例１と同様にして、粘着テープを作製した。 (Example 2)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that acrylic polymer 2 was not used and 100 parts by weight of acrylic polymer 1 was used.
（実施例３）
　アクリル系ポリマー１を用いず、アクリル系ポリマー２を１００重量部用いたこと以外は実施例１と同様にして、粘着テープを作製した。 (Example 3)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that acrylic polymer 1 was not used and 100 parts by weight of acrylic polymer 2 was used.
（実施例４）
　アクリル系ポリマー１を用いず、アクリル系ポリマー２を９５重量部、アクリル系ポリマー４（ポリアクリル酸（富士フィルム和光純薬製、製品名ポリアクリル酸　５０００））を５重量部使用した以外は、実施例１と同様にして、粘着テープを作製した。 (Example 4)
Acrylic polymer 1 was not used, 95 parts by weight of acrylic polymer 2, and 5 parts by weight of acrylic polymer 4 (polyacrylic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., product name polyacrylic acid 5000)) were used. An adhesive tape was produced in the same manner as in Example 1.
（実施例５）
　アミン１の使用量を０．５重量部としたこと以外は、実施例１と同様にして、粘着テープを作製した。 (Example 5)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that the amount of Amine 1 used was 0.5 parts by weight.
（実施例６）
　アミン１の使用量を１０．０重量部としたこと以外は、実施例１と同様にして、粘着テープを作製した。 (Example 6)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that the amount of Amine 1 used was 10.0 parts by weight.
（実施例７）
　アミン１に代えて、アミン２（２，２，６，６－テトラメチル－４－ピペリジルメタクリレート、ＡＤＥＫＡ製：ＬＡ－８７）を１０．０重量部使用したこと以外は、実施例１と同様にして、粘着テープを作製した。 (Example 7)
The procedure was the same as in Example 1 except that 10.0 parts by weight of amine 2 (2,2,6,6-tetramethyl-4-piperidyl methacrylate, manufactured by ADEKA: LA-87) was used instead of amine 1. to prepare an adhesive tape.
（実施例８）
　アミン１に代えて、アミン３（ジオクチルアミン、富士フィルム和光純薬製）を１０．０重量部使用したこと以外は、実施例１と同様にして、粘着テープを作製した。 (Example 8)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that 10.0 parts by weight of Amine 3 (dioctylamine, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was used instead of Amine 1.
（実施例９）
　アクリル系ポリマー１を用いず、アクリル系ポリマー２を９０重量部、アクリル系ポリマー４を１０重量部使用したこと以外は、実施例１と同様にして、粘着テープを作製した。 (Example 9)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that acrylic polymer 1 was not used, and 90 parts by weight of acrylic polymer 2 and 10 parts by weight of acrylic polymer 4 were used.
（実施例１０）
　アクリル系ポリマー１、アクリル系ポリマー２を用いず、アクリル系ポリマー５を１００重量部使用したこと以外は、実施例１と同様にして、粘着テープを作製した。 (Example 10)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that acrylic polymer 1 and acrylic polymer 2 were not used, and 100 parts by weight of acrylic polymer 5 was used.
（比較例１）
　アミン１を用いなかったこと以外は、実施例１と同様にして、粘着テープを作製した。 (Comparative example 1)
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1, except that Amine 1 was not used.
（比較例２）
　アミン１に代えて、１級アミンであるアミン４（ポリオキシプロピレンジアミン、ＨＵＮＴＭＡＮ製：ジェファーミン　Ｄ－４００）を１０．０重量部使用したこと以外は、実施例１と同様にして、粘着テープを作製した。 (Comparative example 2)
Adhesive tape was prepared in the same manner as in Example 1, except that 10.0 parts by weight of primary amine amine 4 (polyoxypropylene diamine, manufactured by HUNTMAN: Jeffamine D-400) was used instead of amine 1. was made.
（比較例３）
　アクリル系ポリマー１及びアクリルポリマー２に代えて、カルボキシル基を含有しないアクリル系ポリマー３（三菱ケミカル製：コーポニール　Ｎ－２９９３）を１００重量部と、カルボキシル基を含有しないアクリル系オリゴマー１（根上工業製：アートレジン　ＵＮ－９０４Ｍ）を３０重量部使用したこと以外は、実施例１と同様にして、粘着テープを作製した。 (Comparative Example 3)
Instead of acrylic polymer 1 and acrylic polymer 2, 100 parts by weight of acrylic polymer 3 containing no carboxyl group (manufactured by Mitsubishi Chemical: Coponyl N-2993) and acrylic oligomer 1 containing no carboxyl group (Negami Kogyo A pressure-sensitive adhesive tape was prepared in the same manner as in Example 1, except that 30 parts by weight of Artresin UN-904M) was used.
＜粘着層の酸価の測定＞
　各実施例および各比較例の粘着テープが備える粘着層の酸価［ｍｇＫＯＨ／ｇ］を以下の方法で測定した。具体的には、まず、粘着層を形成するための樹脂組成物を、１ｇ秤量し、この樹脂組成物をコニカルビーカー中において、テトラヒドロフラン（ＴＨＦ）３０ｇに溶解させ、その後、フェノールフタレインを２、３滴添加した。そして、０．１ＮのＫＯＨ溶液（溶媒：２－プロパノール（ＩＰＡ））をビュレットから滴下して中和点を求めることにより算出した。 <Measurement of acid value of adhesive layer>
The acid value [mgKOH/g] of the adhesive layer included in the adhesive tape of each example and each comparative example was measured by the following method. Specifically, first, 1 g of a resin composition for forming an adhesive layer is weighed, and this resin composition is dissolved in 30 g of tetrahydrofuran (THF) in a conical beaker. 3 drops were added. Then, a 0.1N KOH solution (solvent: 2-propanol (IPA)) was added dropwise from a burette, and the neutralization point was calculated.
＜ガラス転移点の測定＞
　（メタ）アクリル系ポリマーＡのガラス転移点は、ＪＩＳ　Ｋ７１２１に基づいて、示差走査熱量測定法（ＤＳＣ法）により測定した。 <Measurement of glass transition point>
The glass transition point of (meth)acrylic polymer A was measured by differential scanning calorimetry (DSC method) based on JIS K7121.
＜粘着力＞
　各実施例および各比較例の粘着テープの粘着力は、ＪＩＳ　Ｚ０２３７（２００９）の１８０°剥離強度の測定方法（方法１：テープ及びシートをステンレス試験板に対して１８０°に引きはがす試験方法）に準拠して測定した。具体的には、表面を洗浄したシリコンウエハに粘着テープを圧着装置（ローラの質量２ｋｇ）を用いて圧着させて、シリコンウエハに対して１８０°で粘着テープを引き剥がした際の１８０°剥離強度Ｓ０を、温度２３℃湿度５０％の環境下において、万能型引張試験機（ＯＲＩＥＮＴＥＣ社製　テンシロン　型番：ＲＴＧ－１２１０）で測定した。 <Adhesive strength>
The adhesive strength of the adhesive tape of each example and each comparative example was determined by the 180° peel strength measurement method of JIS Z0237 (2009) (Method 1: a test method in which a tape and a sheet are peeled off at 180° against a stainless steel test plate). Measured according to Specifically, the pressure-sensitive adhesive tape was pressed onto the surface-cleaned silicon wafer using a pressure-bonding device (roller mass: 2 kg), and the pressure-sensitive adhesive tape was peeled off from the silicon wafer at 180°. S 0 was measured with a universal tensile tester (Tensilon model number: RTG-1210 manufactured by ORIENTEC) in an environment with a temperature of 23° C. and a humidity of 50%.
　また、表面を洗浄したシリコンウエハに粘着テープを圧着装置（ローラの質量２ｋｇ）を用いて圧着させて、粘着テープに対して、高圧水銀灯により紫外線を１５０ｍＪ／ｃｍ２照射した。その後、シリコンウエハに対して１８０°で粘着テープを引き剥がした際の１８０°剥離強度Ｓ１を上記同様に測定した。測定条件を以下に示す。
（測定条件）
　測定モード　　：引張り
　引張り速度　　：３００ｍｍ／ｍｉｎ
　チャック間距離：５０ｍｍ
　測定サンプル幅：２０ｍｍ Further, an adhesive tape was pressed onto the surface-cleaned silicon wafer using a pressure bonding device (roller mass: 2 kg), and the adhesive tape was irradiated with ultraviolet rays of 150 mJ/cm 2 from a high-pressure mercury lamp. Thereafter, the 180° peel strength S1 when the adhesive tape was peeled off from the silicon wafer at 180° was measured in the same manner as described above. Measurement conditions are shown below.
(Measurement condition)
Measurement mode: Tensile Tensile speed: 300mm/min
Distance between chucks: 50mm
Measurement sample width: 20mm
　上記測定条件にて、紫外線照射前の粘着力と紫外線照射後の粘着力を測定し、それぞれ下記評価基準により評価した。
（評価基準：紫外線照射前の粘着力）
　Ａ：８．０Ｎ／２０ｍｍ以上
　Ｂ：４．０Ｎ／２０ｍｍ以上８．０Ｎ／２０ｍｍ未満
　Ｃ：４．０Ｎ／２０ｍｍ未満
（評価基準：紫外線照射後の粘着力）
　Ａ：０．５Ｎ／２０ｍｍ未満
　Ｂ：０．５Ｎ／２０ｍｍ以上１．０Ｎ／２０ｍｍ未満
　Ｃ：１．０Ｎ／２０ｍｍ以上 Under the above measurement conditions, the adhesive strength before ultraviolet irradiation and the adhesive strength after ultraviolet irradiation were measured and evaluated according to the following evaluation criteria.
(Evaluation criteria: adhesive strength before UV irradiation)
A: 8.0 N / 20 mm or more B: 4.0 N / 20 mm or more and less than 8.0 N / 20 mm C: less than 4.0 N / 20 mm (evaluation criteria: adhesive strength after ultraviolet irradiation)
A: Less than 0.5 N/20 mm B: 0.5 N/20 mm or more and less than 1.0 N/20 mm C: 1.0 N/20 mm or more
＜高温保管時の粘着力変動率の評価＞
　各実施例および各比較例の粘着テープを、４０℃の恒温機内で１か月間保管し、その後、２３℃５０％ＲＨ雰囲気下に２時間以上保管し、テープ温度を２３℃に調整したのち、上記粘着力と同様の方法によって、１８０°剥離強度を測定した。そして、保管前の粘着テープの粘着力に対する保管後の粘着テープの粘着力の比を粘着力の変動率として算出し、下記評価基準に基づいて、高温保管時の粘着力変動率を評価した。
（評価基準：高温保管時の粘着力変動率）
　Ａ：０．９０以以上
　Ｂ：０．８５以上０．９０未満
　Ｃ：０．８５未満 <Evaluation of Adhesive Force Change Rate During High-Temperature Storage>
The adhesive tape of each example and each comparative example was stored in a constant temperature machine at 40°C for 1 month, then stored in an atmosphere of 23°C and 50% RH for 2 hours or more, and the tape temperature was adjusted to 23°C. The 180° peel strength was measured in the same manner as for the adhesive strength. Then, the ratio of the adhesive strength of the adhesive tape after storage to the adhesive strength of the adhesive tape before storage was calculated as an adhesive strength variation rate, and the adhesive strength variation rate during high-temperature storage was evaluated based on the following evaluation criteria.
(Evaluation criteria: Adhesion change rate during high temperature storage)
A: 0.90 or more B: 0.85 or more and less than 0.90 C: less than 0.85
＜二重結合当量＞
　二重結合当量は、「化学製品の酸価，けん化価，エステル価，よう素価，水酸基価及び不けん化物の試験方法」（ＪＩＳ　Ｋ　００７０）」に沿って、よう素価を測定し二重結合量を求めた。具体的には、試料に一塩化よう素溶液を添加し二重結合に付加させ、過剰のIをチオ硫酸ナトリウム溶液で滴定し、以下の式で求めた。
　Ａ＝｛（Ｂ－Ｃ）×ｆ×１．２６９｝／Ｓ
　Ａ：よう素価
　Ｂ：空試験に用いたチオ硫酸ナトリウム溶液の量（ｍＬ）
　Ｃ：滴定に用いたチオ硫酸ナトリウム溶液の量（ｍＬ）
　ｆ：チオ硫酸ナトリウム溶液のファクター
　Ｓ：試料の質量（ｇ） <Double bond equivalent>
The double bond equivalent is determined by measuring the iodine value in accordance with “Testing methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter of chemical products” (JIS K 0070). A heavy bond amount was determined. Specifically, an iodine monochloride solution was added to the sample to add it to the double bond, and excess I was titrated with a sodium thiosulfate solution and obtained by the following formula.
A = {(BC) x f x 1.269}/S
A: Iodine value B: Amount of sodium thiosulfate solution used for blank test (mL)
C: Amount of sodium thiosulfate solution used for titration (mL)
f: factor of sodium thiosulfate solution S: mass of sample (g)
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　本発明の粘着テープは、半導体ウエハ加工用テープ、特にはダイシング工程で用いる粘着テープとして、産業上の利用可能性を有する。 The adhesive tape of the present invention has industrial applicability as a semiconductor wafer processing tape, particularly as an adhesive tape used in a dicing process.

Claims (10)

  1. 　基材と、該基材の少なくとも一方の面に積層された粘着層と、を備え、
    　前記粘着層が、カルボキシル基を有する（メタ）アクリル系ポリマーと、２級以上のアミン基を有するアミン化合物と、光重合開始剤と、を含有し、
    　前記アミン化合物の含有量が、前記（メタ）アクリル系ポリマー１００重量部に対して、０．１重量部以上であり、
    　前記粘着層の酸価が、１０ｍｇＫＯＨ／ｇ以上である、
    　粘着テープ。     A base material and an adhesive layer laminated on at least one surface of the base material,
    The adhesive layer contains a (meth) acrylic polymer having a carboxyl group, an amine compound having a secondary or higher amine group, and a photopolymerization initiator,
    The content of the amine compound is 0.1 parts by weight or more with respect to 100 parts by weight of the (meth)acrylic polymer,
    The adhesive layer has an acid value of 10 mgKOH/g or more,
    Adhesive tape.
  2. 　前記アミン化合物の含有量が、前記（メタ）アクリル系ポリマー１００重量部に対して、１５重量部以下である、
    　請求項１に記載の粘着テープ。     The content of the amine compound is 15 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.
    The adhesive tape according to claim 1.
  3. 　前記アミン化合物が、環状アミン化合物を含む、
    　請求項１又は２に記載の粘着テープ。     wherein the amine compound comprises a cyclic amine compound;
    The adhesive tape according to claim 1 or 2.
  4. 　前記環状アミン化合物が、脂環式アミンを含む、
    　請求項３に記載の粘着テープ。     wherein the cyclic amine compound comprises an alicyclic amine;
    The adhesive tape according to claim 3.
  5. 　前記環状アミン化合物が、１，４－ジアザビシクロ［２，２，２］オクタン又はその誘導体を含む、
    　請求項３又は４に記載の粘着テープ。     wherein the cyclic amine compound comprises 1,4-diazabicyclo[2,2,2]octane or a derivative thereof;
    The adhesive tape according to claim 3 or 4.
  6. 　前記粘着層の酸価が、１００ｍｇＫＯＨ／ｇ以下である、
    　請求項１～５のいずれか一項に記載の粘着テープ。     The adhesive layer has an acid value of 100 mgKOH/g or less,
    The adhesive tape according to any one of claims 1-5.
  7. 　前記（メタ）アクリル系ポリマーが、末端及び／又は側鎖に重合性二重結合を有する、
    　請求項１～６のいずれか一項に記載の粘着テープ。     The (meth)acrylic polymer has a polymerizable double bond at the end and/or side chain,
    The adhesive tape according to any one of claims 1-6.
  8. 　前記（メタ）アクリル系ポリマーが、下記式（１）で表される構成単位を有する、
    　請求項１～７のいずれか一項に記載の粘着テープ。
    Figure JPOXMLDOC01-appb-C000001
    （式中、Ｒ１は、重合性二重結合を有する有機基を示し、Ｒ２は、単結合又は炭素数１～６の有機基を示し、Ｒ３は、水素原子又はメチル基を示す。）     The (meth) acrylic polymer has a structural unit represented by the following formula (1),
    The adhesive tape according to any one of claims 1-7.
    Figure JPOXMLDOC01-appb-C000001
    (In the formula, R 1 represents an organic group having a polymerizable double bond, R 2 represents a single bond or an organic group having 1 to 6 carbon atoms, and R 3 represents a hydrogen atom or a methyl group. )
  9. 　前記粘着層が、イソシアネート化合物を含み、
    　該イソシアネート化合物の含有量が、前記（メタ）アクリル系ポリマー１００重量部に対して、４．０重量部以下である、
    　請求項１～８のいずれか一項に記載の粘着テープ。     The adhesive layer contains an isocyanate compound,
    The content of the isocyanate compound is 4.0 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.
    The adhesive tape according to any one of claims 1-8.
  10. 　請求項１～９のいずれか一項に記載の粘着テープと、被着体と、を貼り合わせる貼合工程と、
    　前記粘着テープと前記被着体とを貼り合わせた状態で、前記被着体を加工するダイシング工程と、
    　該ダイシング工程後の粘着テープに紫外線を照射する紫外線照射工程と、を有し、
    　前記被着体が、半導体ウエハ、半導体デバイス、又は各種半導体パッケージである、
    　加工方法。     A lamination step of laminating the adhesive tape according to any one of claims 1 to 9 and an adherend,
    A dicing step of processing the adherend while the adhesive tape and the adherend are bonded together;
    and an ultraviolet irradiation step of irradiating the adhesive tape after the dicing step with ultraviolet rays,
    The adherend is a semiconductor wafer, a semiconductor device, or various semiconductor packages,
    processing method.
PCT/JP2022/042144 2021-11-12 2022-11-11 Adhesive tape and processing method WO2023085409A1 (en)

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WO2016056269A1 (en) * 2014-01-23 2016-04-14 古河電気工業株式会社 Adhesive tape for protecting semiconductor wafer surface and method for processing semiconductor wafer
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JP2004300405A (en) * 2003-03-20 2004-10-28 Toyo Ink Mfg Co Ltd Adhesive composition and adhesive sheet
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