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
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/30—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers
  • B32B27/308—Layered products comprising a layer of synthetic resin comprising vinyl (co)polymers; comprising acrylic (co)polymers comprising acrylic (co)polymers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/40—Layered products comprising a layer of synthetic resin comprising polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D123/00—Coating compositions based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Coating compositions based on derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D175/00—Coating compositions based on polyureas or polyurethanes; Coating compositions based on derivatives of such polymers
  • C09D175/04—Polyurethanes
  • C09D175/14—Polyurethanes having carbon-to-carbon unsaturated bonds
• • 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
  • C09J201/00—Adhesives based on unspecified macromolecular compounds
• • 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
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
  • C09J7/29—Laminated material
• • 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 potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table 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
• • 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 potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table 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
  • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
  • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting
• • 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
  • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
  • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
  • H01L21/6835—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support
  • H01L21/6836—Wafer tapes, e.g. grinding or dicing support tapes
• • 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
  • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
  • C09J2203/326—Applications of adhesives in processes or use of adhesives in the form of films or foils for bonding electronic components such as wafers, chips or semiconductors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2221/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof covered by H01L21/00
  • H01L2221/67—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere
  • H01L2221/683—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere for supporting or gripping
  • H01L2221/68304—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support
  • H01L2221/68327—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support used during dicing or grinding

Definitions

• the present invention relates to an adhesive sheet for semiconductor processing and a method for manufacturing a semiconductor device.
• the pre-dicing method is a method in which grooves of a predetermined depth are formed on the surface of a semiconductor wafer using a dicing blade or the like, and then the semiconductor wafer is ground from the back side to the grooves, thereby singulating into semiconductor chips. .
• the stealth dicing method after forming a modified region inside a semiconductor wafer by irradiating a laser beam, the semiconductor wafer is ground from the back surface side, and the modified region is used as a splitting starting point to cut semiconductor chips. It is a method of singulating into pieces. These methods also use a back grind sheet to protect the surface of the semiconductor wafer.
• Patent Document 1 as an adhesive sheet for protecting the surface of a semiconductor wafer applicable to the pre-dicing method or the stealth pre-dicing method, a substrate film and an intermediate layer provided on at least one side of the substrate film and made of an adhesive are disclosed. and an outermost adhesive layer provided on the outermost layer on the opposite side of the base film of the intermediate layer, wherein the intermediate layer is cured by a curing treatment after the adhesive sheet is formed.
• a pressure-sensitive adhesive sheet for protecting the surface of a semiconductor wafer is disclosed which is made of a hardening material.
• the adhesive sheet for protecting the surface of a semiconductor wafer of Patent Document 1 it is possible to suppress the kerf shift in which the original chip spacing collapses after the semiconductor wafer is singulated into chips, and to prevent contamination due to grinding dust of the semiconductor wafer. can be suppressed, and it is possible to prevent adhesive residue on the chip when the surface protection tape is peeled off.
• back surface the surface of the back grind sheet attached to the semiconductor wafer opposite to the surface attached to the semiconductor wafer (hereinafter also referred to as "back surface") is fixed by a support device such as a chuck table. be. Then, the back surface of the semiconductor wafer fixed on the table of the support device through the back grind sheet is ground while cooling water is supplied to the grinding surface for removing heat and grinding debris from the grinding.
• the part where the grinding dust exists is the starting point, and the impact when fixing the semiconductor wafer to the table, during the backgrinding. Cracks may occur in the semiconductor wafer or the semiconductor chip due to the pressure, vibration, and the like. Since the grinding dust adheres to the back surface of the back grind sheet while being contained in the cooling water, it is necessary to reduce the amount of grinding dust adhered to the back surface of the back grind sheet in order to suppress the occurrence of cracks. be.
• the pressure-sensitive adhesive sheet for protecting the surface of a semiconductor wafer of Patent Literature 1 cannot sufficiently meet the demand for reducing the amount of grinding dust adhering to the back surface of the back grind sheet.
• the present invention has been made in view of the above circumstances, and aims to provide a semiconductor processing pressure-sensitive adhesive sheet in which the amount of adhered grinding dust is reduced, and a method for manufacturing a semiconductor device using the semiconductor processing pressure-sensitive adhesive sheet. aim.
• a semiconductor processing pressure-sensitive adhesive sheet having, in this order, a surface coat layer containing a polyolefin resin, a buffer layer, a base material, and a pressure-sensitive adhesive layer. , completed the following invention.
• the present invention relates to the following [1] to [11].
• [1] having a surface coat layer, a buffer layer, a substrate and an adhesive layer in this order, The pressure-sensitive adhesive sheet for semiconductor processing, wherein the surface coat layer is a layer containing a polyolefin resin.
• the polyolefin-based resin contains structural units derived from a chain olefin having 2 to 6 carbon atoms.
• the polyolefin resin further contains a structural unit derived from a monomer having an oxygen atom and an ethylenically unsaturated bond.
• a method of manufacturing a semiconductor device comprising: [11] A dividing line forming step, which is the step a of forming a groove in the surface of a semiconductor wafer or the step b of forming a modified region inside the semiconductor wafer from the front surface or the back surface of the semiconductor wafer; After the step a, or before or after the step b, the adhesive sheet for semiconductor processing according to any one of the above [1] to [9] is applied to the surface of the semiconductor wafer using the adhesive layer as an attachment surface.
• a sheet pasting step to be pasted on With the surface coating layer side of the adhesive sheet for semiconductor processing attached to the semiconductor wafer fixed by a support device, the back surface of the semiconductor wafer is ground to form a plurality of semiconductor chips starting from the grooves or modified regions.
• a grinding and singulation step which singulates into The method for manufacturing a semiconductor device according to the above [10], comprising:
• the present invention it is possible to provide a semiconductor processing pressure-sensitive adhesive sheet with reduced adhesion of grinding dust, and a method for manufacturing a semiconductor device using the semiconductor processing pressure-sensitive adhesive sheet.
• (meth)acrylic acid refers to both “acrylic acid” and “methacrylic acid”, and the same applies to other similar terms.
• the term "energy ray” means an electromagnetic wave or charged particle beam that has an energy quantum, and examples thereof include ultraviolet rays, radiation, electron beams, and the like.
• Ultraviolet rays can be applied by using, for example, an electrodeless lamp, a high-pressure mercury lamp, a metal halide lamp, a UV-LED, or the like as an ultraviolet light source.
• the electron beam can be generated by an electron beam accelerator or the like.
• energy ray-polymerizable means the property of polymerizing by irradiation with energy rays.
• energy ray curability means the property of being cured by irradiation with energy rays
• non-energy ray curability means the property of not having energy ray curability.
• the "front surface” of a semiconductor wafer refers to the surface on which circuits are formed
• the "back surface” refers to the surface on which no circuits are formed.
• the adhesive sheet for semiconductor processing of the present embodiment (hereinafter also referred to as "adhesive sheet") has a surface coat layer, a buffer layer, a base material and an adhesive layer in this order, and the surface coat layer is a polyolefin-based It is an adhesive sheet for semiconductor processing containing a resin.
• the pressure-sensitive adhesive sheet of the present embodiment is attached to the surface of a semiconductor device, which is a work, and is used to apply a predetermined processing to the semiconductor device while protecting the surface. After subjecting the work to predetermined processing, the adhesive sheet of the present embodiment is removed from the semiconductor device by peeling.
• semiconductor device refers to all devices that can function by utilizing semiconductor characteristics, such as a semiconductor wafer, a semiconductor chip, an electronic component including the semiconductor chip, and an electronic component comprising the electronic component. Examples include electronic devices.
• the adhesive sheet of the present embodiment is suitable for processing semiconductor wafers.
• the pressure-sensitive adhesive sheet of the present embodiment may or may not have layers other than the surface coat layer, the buffer layer, the substrate, and the pressure-sensitive adhesive layer.
• Layers other than the substrate and the adhesive layer include, for example, an intermediate layer provided between the substrate and the adhesive layer, and a release sheet provided on the surface of the adhesive layer opposite to the substrate. .
• Each member constituting the pressure-sensitive adhesive sheet of the present embodiment will be described below in order.
• the surface coat layer is a layer provided on the side opposite to the base material of the buffer layer, and is a layer fixed by a supporting device when processing the semiconductor device.
• the surface coat layer is a layer containing a polyolefin-based resin, and has a property to which water containing grinding dust is difficult to adhere. Therefore, the pressure-sensitive adhesive sheet of the present embodiment has a reduced amount of grinding dust adhering to the back surface, and can suppress damage to the workpiece due to the grinding dust adhering to the back surface.
• the polyolefin resin contained in the surface coat layer is a resin obtained by polymerizing a monomer containing at least an olefin.
• the "polyolefin-based resin” in the present embodiment is a resin obtained by homopolymerizing an olefin or a resin obtained by copolymerizing an olefin with a monomer other than an olefin, and has 50 structural units derived from an olefin. It means any of the resins containing more than mass %.
• olefin in the present embodiment means an unsaturated hydrocarbon having an ethylenically unsaturated bond, and heteroatom-containing compounds are not included in the term “olefin” in the present embodiment.
• ethylenically unsaturated bond in the present embodiment means a carbon-carbon double bond capable of addition reaction, and does not include the double bond of the aromatic ring.
• a group containing an ethylenically unsaturated bond may be simply referred to as an "unsaturated group”.
• Polyolefin-based resins may be used alone or in combination of two or more.
• the content of structural units derived from olefins in the polyolefin resin is not particularly limited, but is preferably 70% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more.
• the content of structural units derived from olefin in the polyolefin resin may be 100% by mass, preferably 99.5% by mass or less, more preferably 99% by mass or less.
• the content of structural units derived from olefins in the polyolefin resin is equal to or less than the above upper limit, it is possible to incorporate structural units derived from monomers other than olefins for the purpose of improving solvent solubility and the like. There is a tendency that the formation of the surface coating layer by is facilitated.
• olefins constituting polyolefin resins include chain olefins, cyclic olefins, and aromatic vinyl compounds.
• the olefins constituting the polyolefin-based resin may be used singly or in combination of two or more.
• chain olefins examples include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 2-methyl-1-propene, 3- Chain monoolefins such as methyl-1-pentene, 4-methyl-1-pentene, 5-methyl-1-hexene; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1, Chain non-conjugated dienes such as 4-hexadiene; 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-phenyl-1,3-butadiene, 1, Chain conjugated dienes such as 3-hexadiene; Among these, chain olefins having 2 to 6 carbon atoms are preferred, and ethylene and propylene are more preferred.
• Cyclic olefins include, for example, cyclic monoolefins such as cyclobutene, cyclopentene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, and cyclooctene; cyclohexadiene, methylcyclohexadiene, cyclooctadiene, methylcyclooctadiene, phenylcyclooctadiene, etc.
• cyclic monoolefins such as cyclobutene, cyclopentene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, and cyclooctene
• cyclohexadiene methylcyclohexadiene
• cyclooctadiene methylcyclooctadiene
• phenylcyclooctadiene
• cyclic diolefins of polycyclic olefins such as 6,11-tetraene; Among these, tetracyclododecene is preferable from the viewpoint of improving solvent solubility and facilitating the formation of a surface coat layer by coating.
• aromatic vinyl compounds examples include styrene, o-methylstyrene, m-methylstyrene and p-methylstyrene.
• Examples of monomers other than olefins that may be copolymerized with olefins include monomers having an oxygen atom and an ethylenically unsaturated bond, monomers having a nitrogen atom and an ethylenically unsaturated bond, and the like. Monomers other than olefins may be used singly or in combination of two or more.
• Examples of monomers having an oxygen atom and an ethylenically unsaturated bond include acid anhydrides such as maleic anhydride, methyl maleic anhydride, dimethyl maleic anhydride, phenyl maleic anhydride, and diphenyl maleic anhydride; Acids, maleic acids such as dimethyl maleate, diethyl maleate, dibutyl maleate, monomethyl maleate; methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cycloalkyl (Meth)acrylic acid and (meth)acrylic acid esters such as cycloalkyl (meth)acrylate, benzyl (meth)acrylate, and isobornyl (meth)acrylate having 3 to 20 carbon atoms in the group; vinyl acetate, vinyl propionate, etc.
• Acids maleic acids such as dimethyl maleate,
• vinyl ester compound Among these, acid anhydrides and vinyl ester compounds are preferred, maleic anhydride and vinyl acetate are more preferred, and maleic anhydride is preferred, from the viewpoint of improving solvent solubility and facilitating the formation of a surface coat layer by coating. More preferred.
• Monomers having a nitrogen atom and an ethylenically unsaturated bond include, for example, maleimide compounds and their derivatives, nitrile-based monomers, and the like.
• maleimide compounds and derivatives thereof include maleimide; N-alkyl-substituted maleimides such as N-methylmaleimide and N-ethylmaleimide; N-aryl-substituted maleimides such as N-phenylmaleimide;
• nitrile-based monomers include acrylonitrile and methacrylonitrile.
• the polyolefin resin is a structural unit derived from a chain olefin having 2 to 6 carbon atoms (hereinafter referred to as a "chain olefin structural unit (A )”), and more preferably contains one or more selected from the group consisting of structural units derived from ethylene and structural units derived from propylene.
• chain olefin structural unit (A ) a structural unit derived from a chain olefin having 2 to 6 carbon atoms
• the polyolefin resin is a monomer having an oxygen atom and an ethylenically unsaturated bond together with the chain olefin structural unit (A). It is preferable to contain a structural unit derived from (hereinafter also referred to as "a structural unit (B) containing an oxygen atom").
• a structural unit (B) containing an oxygen atom a structural unit derived from (hereinafter also referred to as "a structural unit (B) containing an oxygen atom”).
• a structural unit (B) containing an oxygen atom the content of the chain olefin structural unit (A) in the polyolefin resin is particularly limited.
• the polyolefin-based resin contains a chain olefin-based structural unit (A) and a structural unit (B) containing an oxygen atom
• the content of the structural unit (B) containing an oxygen atom in the polyolefin-based resin is particularly limited. However, it is preferably 0.5 to 20% by mass, more preferably 1 to 10% by mass, still more preferably 1.2 to 5% by mass.
• the polyolefin-based resin together with the chain-like olefin-based structural unit (A), is a structural unit derived from a cyclic olefin (hereinafter referred to as , also referred to as “cyclic olefin-based structural unit (C)”).
• cyclic olefin-based structural unit (C) a structural unit derived from a cyclic olefin (hereinafter referred to as , also referred to as “cyclic olefin-based structural unit (C)”.
• the polyolefin resin contains the chain olefin structural unit (A) and the cyclic olefin structural unit (C)
• the content of the chain olefin structural unit (A) in the polyolefin resin is not particularly limited.
• the polyolefin-based resin contains a chain olefin-based structural unit (A) and a cyclic olefin-based structural unit (C), the content of the cyclic olefin-based structural unit (C) in the polyolefin-based resin is not particularly limited. , preferably 10 to 90% by mass, more preferably 30 to 80% by mass, still more preferably 50 to 75% by mass.
• polyolefin resins examples include homopolymers such as polyethylene, polypropylene, and polybutadiene; ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-maleic anhydride copolymers, ethylene-vinyl acetate copolymers, Ethylene-(meth)acrylate copolymer, ethylene-tetracyclododecene copolymer, propylene-butene copolymer, propylene-maleic anhydride copolymer, propylene-vinyl acetate copolymer, propylene-(meth)acrylate Binary copolymers such as copolymers and propylene-tetracyclododecene copolymers; ethylene-maleic anhydride-vinyl acetate copolymers, ethylene-maleic anhydride-(meth)acrylate copolymers, ethylene-acetic acid Vinyl-(meth)acrylate copoly
• ethylene-vinyl acetate copolymer ethylene-tetracyclodone
• a decene copolymer and an ethylene-butene-maleic anhydride copolymer are preferred, and an ethylene-butene-maleic anhydride copolymer is more preferred.
• the polyolefin resin preferably has solubility in organic solvents. Specifically, the polyolefin resin preferably dissolves in toluene at 23° C. by 1% by mass or more, more preferably by 5% by mass or more, and even more preferably by 8% by mass or more. .
• the heteroatom content in the polyolefin resin is not particularly limited, but is preferably 7% by mass or less, more preferably 0.2 to 4% by mass, and still more preferably 0.5 to 1% by mass.
• the heteroatom content in the polyolefin resin is equal to or less than the above upper limit, there is a tendency that the amount of adhering grinding dust can be further reduced.
• the heteroatom content in the polyolefin resin is equal to or higher than the above lower limit, the solvent solubility tends to be improved, and the formation of a surface coat layer by coating tends to be facilitated.
• the term "heteroatom” means all atoms other than carbon atoms and hydrogen atoms.
• the surface coat layer may contain other components as long as the effects of the present invention are not impaired.
• Other components include, for example, resins other than polyolefin resins; additives such as antistatic agents, antioxidants, softeners, fillers, rust preventives, pigments and dyes; and the like.
• the content of the polyolefin resin with respect to the total amount of the surface coat layer is not particularly limited, but from the viewpoint of further reducing the amount of grinding dust adhesion, it is preferably 90 to 100% by mass, more preferably 95 to 100% by mass, and even more preferably. is 98 to 100% by mass.
• the static contact angle of water at 23° C. (hereinafter also simply referred to as “water contact angle”) with respect to the surface coat layer of the pressure-sensitive adhesive sheet of the present embodiment is preferably 85° or more.
• the water contact angle of the surface coat layer is preferably 90° or more, more preferably 93° or more, and even more preferably 96° or more, from the viewpoint of further reducing the amount of adhered grinding dust.
• the upper limit of the water contact angle of the surface coat layer is not particularly limited, it may be, for example, 150° or less or 100° or less from the viewpoint of ease of manufacture.
• the water contact angle of the surface coat layer is a value measured in conformity with JIS R 3257:1999, and specifically can be measured by the method described in Examples.
• the thickness of the surface coat layer is not particularly limited, it is preferably 0.05 to 10 ⁇ m, more preferably 0.2 to 7 ⁇ m, still more preferably 1 to 4 ⁇ m.
• the thickness of the surface coat layer is at least the above lower limit, it is possible to form a uniform layer, and the amount of adhering grinding dust tends to be sufficiently reduced. Further, when the thickness of the surface coat layer is equal to or less than the above upper limit, the effect of the buffer layer of absorbing irregularities such as foreign matter on the chuck table tends to be easily obtained.
• the buffer layer is a layer provided between the base material and the surface coating layer, and plays a role of absorbing vibrations, impacts, etc. generated during back grinding and preventing cracks from occurring in the workpiece. Furthermore, by providing the buffer layer, it is possible to absorb irregularities such as foreign substances existing on the table of the supporting device, thereby improving the holding property of the adhesive sheet by the supporting device.
• the buffer layer can be formed from a buffer layer-forming composition.
• the buffer layer is preferably a layer obtained by curing a buffer layer-forming composition containing an energy ray-polymerizable compound with energy rays.
• the buffer layer-forming composition preferably contains urethane (meth)acrylate (a1) as the energy ray-polymerizable compound.
• the composition for forming a buffer layer includes, in addition to the urethane (meth)acrylate (a1), a polymerizable compound (a2) having an alicyclic group or a heterocyclic group having 6 to 20 ring-forming atoms. and more preferably one or more selected from the group consisting of a polymerizable compound having a functional group (a3), in addition to the urethane (meth) acrylate (a1), an lipid having 6 to 20 ring atoms It is more preferable to contain a polymerizable compound (a2) having a cyclic group or a heterocyclic group and a polymerizable compound (a3) having a functional group.
• the urethane (meth)acrylate (a1) is a compound having a (meth)acryloyl group and a urethane bond, and has the property of being polymerized by energy ray irradiation.
• the urethane (meth)acrylate (a1) may be used alone or in combination of two or more.
• the weight average molecular weight (Mw) of the urethane (meth)acrylate (a1) is not particularly limited, but is preferably from 1,000 to 100,000, more preferably from 2,000 to 60,000, still more preferably from 3,000 to 20,000.
• the mass average molecular weight (Mw) means a value converted to standard polystyrene measured by a gel permeation chromatography (GPC) method, specifically measured by the method described in Examples. value.
• the number of (meth)acryloyl groups that the urethane (meth)acrylate (a1) has in one molecule is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, still more preferably 1 or 2. is one.
• the urethane (meth)acrylate (a1) can be obtained, for example, by reacting a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound and a polyvalent isocyanate compound with a (meth)acrylate having a hydroxy group. .
• the polyol compound is not particularly limited as long as it is a compound having two or more hydroxy groups.
• Specific examples of polyol compounds include alkylene diols, polyether polyols, polyester polyols, polycarbonate polyols, and the like. Among these, polyester type polyols are preferred.
• the polyol compound may be a bifunctional diol, a trifunctional triol, or a tetrafunctional or higher polyol, preferably a bifunctional diol, and more preferably a polyester type diol.
• a polyol compound may be used individually by 1 type, and may use 2 or more types together.
• polyvalent isocyanate compounds include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate and trimethylhexamethylene diisocyanate; Alicyclic diisocyanates such as ,4'-diisocyanate, ⁇ , ⁇ '-diisocyanatedimethylcyclohexane;4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tolidine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene- aromatic diisocyanates such as 1,5-diisocyanate; Among these, isophorone diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are preferred. Polyvalent isocyanate compounds may be used alone or in combination of two or more.
• the (meth)acrylate having a hydroxyl group to be reacted with the terminal isocyanate urethane prepolymer is not particularly limited as long as it is a compound having a hydroxyl group and a (meth)acryloyl group in at least one molecule.
• (Meth)acrylates having a hydroxy group include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, 5 -Hydroxyalkyl such as hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, etc.) (meth)acrylates; hydroxy group-containing (meth)acrylamides such as N-methylol (meth)acrylamide; reaction products obtained by reacting vinyl alcohol, vinylphenol, diglycidyl ester of bisphenol A with (meth)acrylic acid; is mentioned. Among these, hydroxyalkyl (meth)acrylates are preferred, and 2-hydroxyethy
• Conditions for reacting a terminal isocyanate urethane prepolymer and a (meth)acrylate having a hydroxy group are not particularly limited. Conditions for reacting for 1 to 4 hours can be set.
• the content of the urethane (meth)acrylate (a1) in the buffer layer-forming composition is not particularly limited, but is preferably 10 to 10% with respect to the total amount (100% by mass) of the active ingredients in the buffer layer-forming composition. 70% by mass, more preferably 20 to 60% by mass, and even more preferably 30 to 50% by mass.
• the active ingredient of the composition for forming a buffer layer means the ingredients contained in the composition for forming a buffer layer, excluding the ingredients such as the organic solvent removed in the process of forming the buffer layer. means an ingredient.
• the buffer layer-forming composition contains a polymerizable compound (a2) having an alicyclic or heterocyclic group having 6 to 20 ring-forming atoms (hereinafter referred to as "a polymerizable compound having an alicyclic or heterocyclic group (a2) ”) tends to improve the film formability of the composition for forming a buffer layer.
• a polymerizable compound having an alicyclic or heterocyclic group (a2) tends to improve the film formability of the composition for forming a buffer layer.
• the number of ring-forming atoms refers to the number of atoms constituting the ring itself of a compound having a structure in which atoms are cyclically bonded, and atoms that do not constitute a ring (for example, hydrogen atoms bonded to atoms that constitute a ring). , and when the ring is substituted with a substituent, atoms included in the substituent are not included in the number of ring-forming atoms.
• Atoms forming the ring structure of the heterocyclic group include, for example, a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom and the like.
• the polymerizable compound (a2) having an alicyclic group or a heterocyclic group may be used alone or in combination of two or more.
• the polymerizable compound (a2) having an alicyclic group or heterocyclic group is preferably a compound having a (meth)acryloyl group.
• the number of (meth)acryloyl groups in one molecule of the polymerizable compound (a2) having an alicyclic group or a heterocyclic group is not particularly limited, but is preferably 1 or more, more preferably 1 or 2, More preferably, the number is one.
• the number of ring-forming atoms of the alicyclic group or heterocyclic group in the polymerizable compound (a2) having an alicyclic group or heterocyclic group is 6 to 20, preferably 6 to 18, more preferably 6 to 16, More preferably 7-12.
• Examples of the polymerizable compound (a2) having an alicyclic group or a heterocyclic group include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxy (meth) Alicyclic group-containing (meth)acrylates such as acrylate, cyclohexyl (meth)acrylate, and adamantane (meth)acrylate; heterocyclic group-containing (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate and morpholine (meth)acrylate; mentioned. Among these, alicyclic group-containing (meth)acrylates are preferred, and isobornyl (meth)acrylates are more preferred.
• the content of the polymerizable compound (a2) having an alicyclic group or a heterocyclic group in the buffer layer-forming composition is not particularly limited, but the total amount (100% by mass) of the active ingredients in the buffer layer-forming composition %, preferably 10 to 70% by mass, more preferably 20 to 60% by mass, and even more preferably 30 to 50% by mass.
• the polymerizable compound (a3) having a functional group may be used alone or in combination of two or more.
• Examples of the functional group that the polymerizable compound (a3) having a functional group has include a hydroxyl group, an epoxy group, an amide group, and an amino group.
• the number of functional groups in one molecule of the polymerizable compound (a3) having a functional group is 1 or more, preferably 1 to 3, more preferably 1 or 2, still more preferably 1. be.
• the polymerizable compound (a3) having a functional group is preferably a compound having a (meth)acryloyl group together with the functional group.
• the number of (meth)acryloyl groups in one molecule of the polymerizable compound (a3) having a functional group is not particularly limited, but is preferably one or more, more preferably one or two, and still more preferably one. is.
• Examples of the polymerizable compound (a3) having a functional group include hydroxyl group-containing polymerizable compounds, epoxy group-containing polymerizable compounds, amide group-containing polymerizable compounds, amino group-containing polymerizable compounds, and the like.
• hydroxyl group-containing polymerizable compounds examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate and the like hydroxyl group-containing (meth) acrylate; hydroxyethyl vinyl ether, hydroxybutyl vinyl ether and other vinyl ether compounds; be done.
• epoxy group-containing polymerizable compounds examples include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and allyl glycidyl ether.
• amide group-containing polymerizable compounds include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, and N-methylolpropane(meth)acrylamide. , N-methoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, N-vinylformamide and the like.
• amino group-containing polymerizable compounds examples include amino group-containing (meth)acrylates such as primary amino group-containing (meth)acrylates, secondary amino group-containing (meth)acrylates, and tertiary amino group-containing (meth)acrylates. ) acrylates and the like.
• hydroxyl group-containing (meth)acrylates are preferred, and hydroxyl group-containing (meth)acrylates having an aromatic ring such as 2-hydroxy-3-phenoxypropyl (meth)acrylate are more preferred.
• the content of the polymerizable compound (a3) having a functional group in the buffer layer-forming composition is not particularly limited, but is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, still more preferably 15 to 25% by mass.
• the composition for forming a buffer layer may contain polymerizable compounds other than the components (a1) to (a3) as long as the effects of the present invention are not impaired.
• Other polymerizable compounds include, for example, alkyl (meth)acrylates having an alkyl group having 1 to 20 carbon atoms; vinyl compounds such as styrene, N-vinylpyrrolidone and N-vinylcaprolactam; and the like.
• Other polymerizable compounds may be used singly or in combination of two or more.
• the content of the other polymerizable compound in the buffer layer-forming composition is not particularly limited, but is preferably 0 to 20% by mass with respect to the total amount (100% by mass) of the active ingredients in the buffer layer-forming composition. , more preferably 0 to 10% by mass, more preferably 0 to 2% by mass.
• the composition for forming a buffer layer containing an energy ray-polymerizable compound preferably further contains a photopolymerization initiator from the viewpoint of reducing the polymerization time and the amount of energy ray irradiation due to energy ray irradiation.
• a photoinitiator may be used individually by 1 type, and may use 2 or more types together.
• photopolymerization initiators examples include benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and photosensitizers such as amines and quinones.
• 1-hydroxycyclohexylphenyl ketone 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzylphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and the like.
• 1-hydroxycyclohexylphenyl ketone is preferred.
• the content of the photopolymerization initiator in the buffer layer-forming composition is not particularly limited, but from the viewpoint of allowing the energy ray curing reaction to proceed homogeneously and sufficiently, the total amount of the energy ray polymerizable compound is 100 parts by mass. , preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, still more preferably 0.3 to 5 parts by mass.
• the buffer layer-forming composition may contain other components as long as the effects of the present invention are not impaired.
• Other components include, for example, resin components other than the resins described above; additives such as antistatic agents, antioxidants, softeners, fillers, rust preventives, pigments and dyes;
• the content of the other resin components in the buffer layer-forming composition is not particularly limited, but is preferably 0 to 20% by mass with respect to the total amount (100% by mass) of the active ingredients in the buffer layer-forming composition. More preferably 0 to 10 mass %, still more preferably 0 to 2 mass %.
• the content of other additives in the buffer layer-forming composition is not particularly limited, but each is preferably 0 to 6 with respect to the total amount (100% by mass) of the active ingredients in the buffer layer-forming composition. % by mass, more preferably 0.01 to 5% by mass, still more preferably 0.1 to 3% by mass.
• the Young's modulus of the buffer layer at 23° C. is smaller than the Young's modulus of the substrate at 23° C. Specifically, it is preferably less than 1,200 MPa, more preferably 900 MPa or less. Also.
• the Young's modulus of the buffer layer at 23° C. is preferably 50 MPa or higher, more preferably 100 MPa or higher.
• the Young's modulus of the buffer layer at 23° C. can be measured at a test speed of 200 mm/min according to JIS K 7127:1999.
• the stress relaxation rate of the buffer layer is not particularly limited, it is preferably 70 to 100%, more preferably 75 to 100%, still more preferably 78 to 98%.
• the thickness of the buffer layer is not particularly limited, it is preferably 10 to 70 ⁇ m, more preferably 15 to 50 ⁇ m, still more preferably 20 to 40 ⁇ m.
• the thickness of the buffer layer is at least the above lower limit, the effect of absorbing vibrations, impacts, etc., generated during back grinding and the holding property of the adhesive sheet tend to be enhanced. Further, when the thickness of the buffer layer is equal to or less than the above upper limit value, excessive deformation of the buffer layer tends to be suppressed when the work is processed.
• the pressure-sensitive adhesive layer is a layer provided on the side opposite to the buffer layer of the base material, and is a layer to be attached to the work.
• the adhesive layer is preferably a layer formed from an energy ray-curable adhesive.
• Examples of the energy ray-curable pressure-sensitive adhesive include the following X-type pressure-sensitive adhesive composition, Y-type pressure-sensitive adhesive composition, and XY-type pressure-sensitive adhesive composition.
• X-type adhesive composition Energy ray-curable containing a non-energy ray-curable adhesive resin (hereinafter also referred to as “adhesive resin I”) and an energy ray-curable compound other than the adhesive resin
• Adhesive composition Y-type adhesive composition an energy ray-curable adhesive resin in which an unsaturated group is introduced into the side chain of a non-energy ray-curable adhesive resin (hereinafter, also referred to as "adhesive resin II" ) and does not contain an energy ray-curable compound other than the adhesive resin
• XY-type adhesive composition the energy ray-curable adhesive resin II and other than the adhesive resin and an energy ray-curable pressure-sensitive adhesive composition containing: and an energy ray-curable pressure-sensitive adhesive composition of XY type.
• the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer may be a layer formed from a non-energy ray-curable pressure-sensitive adhesive that does not harden even when irradiated with energy rays.
• non-energy ray-curable adhesives include those containing adhesive resin I but not containing adhesive resin II and energy ray-curable compounds.
• tacky resin is used as a term indicating one or both of tacky resin I and tacky resin II.
• adheresive composition when simply referred to as "adhesive composition", an X-type adhesive composition, a Y-type adhesive composition, an XY-type adhesive composition, and other adhesive compositions The concept also includes things.
• adhesive resins examples include acrylic resins, urethane resins, rubber resins, and silicone resins. Among these, acrylic resins are preferable.
• the acrylic resin preferably contains structural units derived from alkyl (meth)acrylate.
• alkyl (meth)acrylates include alkyl (meth)acrylates in which the alkyl group has 1 to 20 carbon atoms.
• the alkyl group of the alkyl (meth)acrylate may be linear or branched.
• the acrylic resin preferably contains a structural unit derived from an alkyl (meth)acrylate having an alkyl group with 4 or more carbon atoms.
• the structural unit derived from the alkyl (meth)acrylate having 4 or more carbon atoms in the alkyl group contained in the acrylic resin may be one type alone or two or more types.
• the number of carbon atoms in the alkyl group of the alkyl (meth)acrylate having 4 or more carbon atoms in the alkyl group is preferably 4 to 12, more preferably 4 to 8, and still more preferably 4 to 6.
• alkyl (meth)acrylates in which the alkyl group has 4 or more carbon atoms include butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl ( meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate and the like.
• butyl (meth)acrylate is preferred, and butyl acrylate is more preferred.
• the acrylic resin contains a structural unit derived from an alkyl (meth)acrylate in which the alkyl group has 4 or more carbon atoms
• the content thereof is determined from the viewpoint of further improving the adhesive strength of the pressure-sensitive adhesive layer. It is preferably 30 to 90% by mass, more preferably 40 to 80% by mass, still more preferably 45 to 60% by mass in the system resin.
• the acrylic resin contains a structural unit derived from an alkyl (meth)acrylate having 4 or more carbon atoms in the alkyl group, and an alkyl group. It preferably contains a structural unit derived from an alkyl (meth)acrylate having 1 to 3 carbon atoms.
• the structural unit derived from the alkyl (meth)acrylate having 1 to 3 carbon atoms in the alkyl group contained in the acrylic resin may be of one type or two or more types.
• alkyl (meth)acrylates having 1 to 3 carbon atoms in the alkyl group examples include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate and the like. .
• methyl (meth)acrylate and ethyl (meth)acrylate are preferred, methyl (meth)acrylate is more preferred, and methyl methacrylate is even more preferred.
• the acrylic resin contains a structural unit derived from an alkyl (meth)acrylate in which the alkyl group has 1 to 3 carbon atoms, the content thereof is preferably 1 to 35% by mass in the acrylic resin, and more It is preferably 5 to 30% by mass, more preferably 15 to 25% by mass.
• the acrylic resin preferably further contains structural units derived from functional group-containing monomers.
• the acrylic resin contains a structural unit derived from a functional group-containing monomer, the functional group as a cross-linking starting point that reacts with the cross-linking agent or reacts with the unsaturated group-containing compound to create an unsaturated group in the side chain of the acrylic resin.
• Functional groups can be introduced that allow the introduction of saturated groups.
• the structural unit derived from the functional group-containing monomer contained in the acrylic resin may be one type alone or two or more types.
• Examples of functional group-containing monomers include hydroxyl group-containing monomers, carboxy group-containing monomers, amino group-containing monomers, and epoxy group-containing monomers. Among these, hydroxyl group-containing monomers and carboxy group-containing monomers are preferable, and hydroxyl group-containing monomers are more preferable.
• hydroxyl group-containing monomers examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, ) hydroxyalkyl (meth)acrylates such as acrylate and 4-hydroxybutyl (meth)acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol; Carboxy group-containing monomers include, for example, ethylenically unsaturated monocarboxylic acids such as (meth)acrylic acid and crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, maleic acid and citraconic acid, and their anhydrides ; 2-carboxyethyl methacrylate; and the like.
• the acrylic resin contains a structural unit derived from a functional group-containing monomer
• the content is not particularly limited, but preferably 5 to 45% by mass, more preferably 15 to 40% by mass in the acrylic resin. , more preferably 25 to 35% by mass.
• the acrylic resin may contain, in addition to the above structural units, structural units derived from other monomers copolymerizable with acrylic monomers. Constituent units derived from other monomers contained in the acrylic resin may be one type alone or two or more types. Other monomers include, for example, styrene, ⁇ -methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide and the like.
• the acrylic resin may further have an energy ray polymerizable unsaturated group introduced thereinto to impart energy ray curability.
• the unsaturated group is, for example, a functional group of an acrylic resin containing structural units derived from a functional group-containing monomer, and a compound having a reactive substituent and an unsaturated group having reactivity with the functional group (hereinafter referred to as " (also referred to as "unsaturated group-containing compound").
• the unsaturated group-containing compounds may be used singly or in combination of two or more. Examples of the unsaturated group that the unsaturated group-containing compound has include a (meth)acryloyl group, a vinyl group, and an allyl group.
• a (meth)acryloyl group is preferred.
• reactive substituents that the unsaturated group-containing compound has include an isocyanate group and a glycidyl group.
• unsaturated group-containing compounds include (meth)acryloyloxyethyl isocyanate, (meth)acryloylisocyanate, glycidyl (meth)acrylate and the like.
• a functional group that reacts with the unsaturated group-containing compound is not particularly limited, but is preferably 60 to 98 mol%, more preferably 70 to 95 mol%, still more preferably 80 to 93 mol%.
• the ratio of the functional group that reacts with the unsaturated group-containing compound is within the above range, sufficient energy ray curability can be imparted to the acrylic resin, and the functional group that has not reacted with the unsaturated group-containing compound is crosslinked.
• the acrylic resin can be crosslinked by reacting with the agent.
• the mass average molecular weight (Mw) of the acrylic resin is not particularly limited, but is preferably 300,000 to 1,500,000, more preferably 350,000 to 1,000,000, and still more preferably 400,000 to 600,000.
• Mw mass average molecular weight
• Energy ray-curable compound contained in the X-type or XY-type pressure-sensitive adhesive composition, a monomer or oligomer having an unsaturated group in the molecule and capable of being cured by energy ray irradiation is preferable.
• Energy ray-curable compounds include, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,4-butylene glycol di
• Polyvalent (meth)acrylate monomers such as (meth)acrylate and 1,6-hexanediol (meth)acrylate; urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy (meth)acrylate, etc. oligomer; and the like.
• urethane (meth)acrylate oligomers are preferable because they have a relatively high molecular weight and are less likely to lower the elastic modulus of the pressure-sensitive adhesive layer.
• the molecular weight of the energy ray-curable compound is not particularly limited, it is preferably 100 to 12,000, more preferably 200 to 10,000, even more preferably 400 to 8,000, still more preferably 600 to 6,000. be.
• the above molecular weight means the weight average molecular weight (Mw).
• the content of the energy ray-curable compound in the X-type adhesive composition is not particularly limited, but is preferably 40 to 200 parts by mass, more preferably 50 to 150 parts by mass, relative to 100 parts by mass of the adhesive resin. , more preferably 60 to 90 parts by mass.
• the content of the energy ray-curable compound in the X-type pressure-sensitive adhesive composition is within the above range, the balance between the adhesive strength before energy ray irradiation and the releasability after energy ray irradiation tends to be good.
• the content of the energy ray-curable compound in the XY-type adhesive composition is not particularly limited, but is preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass, relative to 100 parts by mass of the adhesive resin. , more preferably 3 to 15 parts by mass.
• the content of the energy ray-curable compound in the XY-type pressure-sensitive adhesive composition is within the above range, the balance between the adhesive strength before energy ray irradiation and the releasability after energy ray irradiation tends to be good.
• the adhesive resin is energy ray-curable, even if the content of the energy ray-curable compound is small, the peeling force tends to be sufficiently reduced after energy ray irradiation. It is in.
• the pressure-sensitive adhesive composition preferably further contains a cross-linking agent.
• the cross-linking agent cross-links the adhesive resins by, for example, reacting with functional groups derived from the functional group-containing monomers of the adhesive resins.
• the cross-linking agents may be used alone or in combination of two or more.
• cross-linking agents examples include isocyanate-based cross-linking agents such as tolylene diisocyanate, hexamethylene diisocyanate, and adducts thereof; epoxy-based cross-linking agents such as ethylene glycol glycidyl ether; hexa[1-(2-methyl)-aziridinyl]trifo aziridine-based cross-linking agents such as sfatriazine; chelate-based cross-linking agents such as aluminum chelate;
• the isocyanate-based cross-linking agent is preferable from the viewpoint of increasing the cohesive strength to further improve the adhesive strength and from the viewpoint of availability.
• the pressure-sensitive adhesive composition contains a cross-linking agent
• its content is not particularly limited, but from the viewpoint of moderately advancing the cross-linking reaction, it is preferably 0.01 to 10 parts per 100 parts by mass of the pressure-sensitive adhesive resin. parts by mass, more preferably 0.03 to 7 parts by mass, and even more preferably 0.05 to 4 parts by mass.
• the adhesive composition preferably further contains a photopolymerization initiator.
• the energy ray-curable pressure-sensitive adhesive contains a photopolymerization initiator, the curing reaction of the energy ray-curable pressure-sensitive adhesive tends to proceed sufficiently even with relatively low-energy energy rays such as ultraviolet rays.
• a photoinitiator may be used individually by 1 type, and may use 2 or more types together.
• photopolymerization initiators examples include benzoin compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and photosensitizers such as amines and quinones.
• 1-hydroxycyclohexylphenyl ketone 2-hydroxy-2-methyl-1-phenyl-propan-1-one
• benzoin benzoin methyl ether
• benzoin ethyl ether benzoin isopropyl ether
• benzylphenyl sulfide tetramethylthiuram monosulfide
• azobisisobutyronitrile dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and the like.
• the energy ray-curable adhesive contains a photopolymerization initiator
• the content is not particularly limited, but from the viewpoint of allowing the energy ray curing reaction to proceed homogeneously and sufficiently, it is added to 100 parts by mass of the adhesive resin. , preferably 0.01 to 10 parts by mass, more preferably 0.03 to 7 parts by mass, still more preferably 0.05 to 5 parts by mass.
• the pressure-sensitive adhesive composition may contain other additives as long as the effects of the present invention are not impaired.
• Other additives include, for example, antistatic agents, antioxidants, softeners, fillers, rust inhibitors, pigments, dyes, and the like.
• the content of other additives in the adhesive composition is not particularly limited, but for each of the total amount (100% by mass) of the active ingredients of the adhesive composition, preferably 0 to 6% by mass, more than It is preferably 0.01 to 5% by mass, more preferably 0.1 to 3% by mass.
• the active ingredient of the pressure-sensitive adhesive composition refers to the components contained in the pressure-sensitive adhesive composition, excluding the components such as the organic solvent removed in the process of forming the pressure-sensitive adhesive layer. means.
• the pressure-sensitive adhesive composition may be diluted with an organic solvent to form a solution, from the viewpoint of further improving coatability onto a substrate, a release sheet, or the like.
• organic solvents include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol and isopropanol.
• An organic solvent may be used individually by 1 type, and may use 2 or more types together.
• the organic solvent the organic solvent used during the synthesis of the adhesive resin may be used as it is, or one or more organic solvents other than the organic solvent used during the synthesis may be added.
• the storage modulus G′ of the pressure-sensitive adhesive layer at 23° C. is not particularly limited, but is preferably 0.05 to 0.5 MPa, more preferably 0.1 to 0.4 MPa, still more preferably 0.12 to 0.3 MPa. is.
• the storage elastic modulus G′ of the pressure-sensitive adhesive layer at 23° C. is within the above range, even if the surface of the work has unevenness, the pressure-sensitive adhesive layer can be obtained with excellent conformability to the uneven shape, and the surface of the work can be smoothed during processing. They tend to be better protected.
• the storage elastic modulus G' of the adhesive layer means the storage elastic modulus G' before curing by energy ray irradiation when the adhesive layer is formed from an energy ray-curable adhesive.
• the storage elastic modulus G′ of the adhesive layer at 23° C. was determined by a torsional shear method using a viscoelasticity measuring device, using a test piece cut out of the adhesive layer with a thickness of 3 mm into a circular shape with a diameter of 8 mm, at a frequency of 1 Hz, Measurement can be performed at a measurement temperature of 23°C.
• the thickness of the pressure-sensitive adhesive layer is not particularly limited, it is preferably 5 to 100 ⁇ m, more preferably 10 to 80 ⁇ m, still more preferably 15 to 60 ⁇ m.
• the thickness of the pressure-sensitive adhesive layer is at least the above lower limit value, excellent adhesiveness can be obtained, and the surface of the work tends to be better protected during processing. Further, when the thickness of the adhesive layer is equal to or less than the above upper limit value, the generation of tape scraps is suppressed when the adhesive sheet is cut, and there is a tendency that damage to the work can be prevented more satisfactorily.
• Examples of the substrate include various resin films.
• Examples of the resin constituting the resin film include polyethylene such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and high-density polyethylene (HDPE); polypropylene, polybutene, polybutadiene, polymethylpentene, and ethylene-norbornene.
• LDPE low-density polyethylene
• LLDPE linear low-density polyethylene
• HDPE high-density polyethylene
• polypropylene polybutene
• polybutadiene polymethylpentene
• ethylene-norbornene ethylene-norbornene
• Polyolefins such as copolymers and norbornene resins; ethylene-based copolymers such as ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, and ethylene-(meth)acrylic acid ester copolymers; polychloride Polyvinyl chloride such as vinyl and vinyl chloride copolymer; Polyester such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and wholly aromatic polyester; Polyurethane, polyimide, polyamide, polycarbonate, fluororesin, polyacetal, modified polyphenylene oxide, polyphenylene sulfide, polysulfone, polyetherketone, acrylic polymer; and the like.
• the substrate may be a single-layer film of a resin film made of one or more resins selected from these resins, or may be a laminated film obtained by laminating two or more of these resin films. Moreover, a modified film such as a crosslinked film of the above resin or an ionomer film may be used.
• the substrate is preferably one or more selected from polyester films, polyamide films, polyimide films and biaxially oriented polypropylene films, more preferably polyester films, and still more preferably polyethylene terephthalate films.
• the Young's modulus of the substrate is not particularly limited, it is preferably 1,000 MPa or more, more preferably 1,800 to 30,000 MPa, and still more preferably 2,500 to 6,000 MPa.
• the Young's modulus of the base material is equal to or higher than the above lower limit, there is a tendency that the effect of suppressing vibration during machining of a workpiece is further improved.
• the Young's modulus of the base material is equal to or less than the above upper limit, workability in attaching to a work and workability in peeling from the work tend to be improved.
• the Young's modulus of the substrate can be measured under the conditions of a test speed of 200 mm/min in accordance with JIS K 7127:1999.
• the thickness of the substrate is not particularly limited, it is preferably 10 to 200 ⁇ m, more preferably 25 to 100 ⁇ m, still more preferably 30 to 70 ⁇ m.
• the thickness of the substrate is at least the above lower limit, there is a tendency that sufficient strength for functioning as a support for the pressure-sensitive adhesive sheet can be obtained.
• the thickness of the base material is equal to or less than the above upper limit value, appropriate flexibility is obtained, and the handleability tends to be improved.
• the "thickness of the base material” means the thickness of the entire base material. means.
• the substrate may contain plasticizers, lubricants, infrared absorbers, ultraviolet absorbers, fillers, colorants, antistatic agents, antioxidants, catalysts, etc., as long as the effects of the present invention are not impaired.
• the substrate may be transparent or opaque, and optionally colored or vapor-deposited. From the viewpoint of improving adhesion with other layers, the base material may have been subjected to a surface treatment such as corona treatment on at least one surface. A layer may be provided.
• the adhesive sheet of the present embodiment may have a release sheet attached to at least one of the surface of the adhesive layer and the surface of the surface coat layer.
• the release sheet protects the surface of the pressure-sensitive adhesive sheet by being releasably attached to the surface before use, and is peeled off and removed when the pressure-sensitive adhesive sheet is to be used.
• the release sheet may be a single-sided release sheet or a double-sided release sheet.
• As the release sheet a release sheet obtained by applying a release agent to a release sheet base material is preferably used.
• a resin film is preferable, and examples of the resin film include polyester films such as polyethylene terephthalate film, polybutylene terephthalate film and polyethylene naphthalate film; polyolefin films such as polypropylene film and polyethylene film; are mentioned.
• release agents include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, and butadiene-based resins; long-chain alkyl-based resins, alkyd-based resins, fluorine-based resins, and the like.
• the thickness of the release sheet is not particularly limited, it is preferably 5 to 200 ⁇ m, more preferably 10 to 100 ⁇ m, still more preferably 20 to 50 ⁇ m.
• the total thickness of the pressure-sensitive adhesive sheet of the present embodiment is not particularly limited, but is preferably 30-300 ⁇ m, more preferably 40-220 ⁇ m, and still more preferably 45-160 ⁇ m.
• the total thickness of the adhesive sheet is at least the above lower limit, the adhesive performance of the adhesive layer, the shock absorption performance of the buffer layer, etc. are appropriately maintained, and the adhesive sheet for semiconductor processing tends to sufficiently exhibit its function.
• the total thickness of the adhesive sheet is equal to or less than the above upper limit, there is a tendency that the peeling force when peeling the work from the adhesive sheet can be reduced.
• the "total thickness of the adhesive sheet” means the thickness from the surface of the surface coat layer of the adhesive sheet to the surface of the adhesive layer, and when a release sheet is provided, the thickness of the release sheet thickness is not included in the total thickness.
• the method for producing the pressure-sensitive adhesive sheet of this embodiment is not particularly limited, and it can be produced by a known method.
• the pressure-sensitive adhesive sheet of the present embodiment includes, for example, a step of forming a pressure-sensitive adhesive layer on one side of a substrate (hereinafter also referred to as a "pressure-sensitive adhesive layer forming step"), and a buffer layer on the other side of the substrate.
• a method comprising a step of forming (hereinafter also referred to as “buffer layer forming step”) and a step of forming a surface coat layer on the side of the buffer layer opposite to the base material (hereinafter also referred to as “surface coat layer forming step”) can be manufactured by The order of these steps is not particularly limited, and if they can be carried out simultaneously, they may be carried out at the same time.
• the pressure-sensitive adhesive layer forming step may be, for example, a method of laminating a pressure-sensitive adhesive layer formed on a release sheet to the surface of the base material, and directly applying the pressure-sensitive adhesive composition to the surface of the base material.
• a method of forming an agent layer may also be used.
• the buffer layer forming step may be, for example, a method of laminating a buffer layer formed on a release sheet to the surface of the base material, and applying a buffer layer-forming composition directly to the surface of the base material.
• a method of forming a layer may be used.
• the surface coat layer forming step may be, for example, a method of bonding a surface coat layer formed on a release sheet to the surface of the buffer layer on the substrate, and a surface coat layer is formed on the surface of the buffer layer on the substrate.
• a surface coating layer may be formed by directly applying a coating liquid for coating.
• the buffer layer forming step and the surface coat layer forming step may be a method in which the surface coat layer and the buffer layer are provided on the release sheet in this order, and then the buffer layer is attached to the surface of the substrate.
• a method for forming a pressure-sensitive adhesive layer, a buffer layer or a surface coat layer on a release sheet for example, a pressure-sensitive adhesive composition, a buffer layer-forming composition, or a surface coat layer coating solution is applied onto a release sheet by a known method. After application by a method, energy beam irradiation, heat drying, or the like may be performed, if necessary.
• Examples of methods for applying the pressure-sensitive adhesive composition, buffer layer-forming composition, or surface coating layer coating liquid include spin coating, spray coating, bar coating, knife coating, roll coating, and blade coating. , a die coating method, a gravure coating method, and the like.
• the curing treatment by energy ray irradiation may be performed once or in multiple steps.
• the buffer layer-forming composition may be completely cured by irradiation with energy rays, and then on the release sheet After completely curing the composition for forming a buffer layer, it may be attached to the substrate.
• the curing treatment is performed in multiple steps, after forming a coating film of the buffer layer-forming composition on the release sheet, the buffer layer-forming composition is semi-cured on the release sheet without being completely cured.
• the composition for forming a buffer layer may be completely cured by curing to the state of (1), bonding it to the base material, and then irradiating the energy beam again.
• Ultraviolet rays are preferable as the energy rays irradiated in the curing treatment of the composition for forming a buffer layer.
• the coating film of the composition for forming a buffer layer may be in a state of being exposed to the outside. It is preferable to irradiate the energy beam without exposure to
• the pressure-sensitive adhesive sheet of the present embodiment is suitable for back-grinding, and is suitable for back-grinding in which the back surface of a semiconductor wafer is ground while the pressure-sensitive adhesive sheet of the present embodiment is attached to the circuit-forming surface of the semiconductor wafer.
• the pressure-sensitive adhesive sheet of the present embodiment has the effect of suppressing the generation of cracks when thinning a semiconductor wafer, and is therefore suitable for processes such as pre-dicing and stealth pre-dicing.
• the method for manufacturing the semiconductor device of this embodiment includes: a step of attaching the adhesive sheet for semiconductor processing of the present embodiment to the surface of a semiconductor wafer using the adhesive layer as an attachment surface; a step of grinding the back surface of the semiconductor wafer in a state where the surface coating layer side of the semiconductor processing adhesive sheet attached to the semiconductor wafer is fixed by a supporting device;
• a method for manufacturing a semiconductor device comprising:
• the method for manufacturing the semiconductor device of this embodiment includes: a step of forming grooves on the surface of a semiconductor wafer, or step b of forming a modified region inside the semiconductor wafer from the front surface or the back surface of the semiconductor wafer; After the step a, or before or after the step b, a sheet attaching step of attaching the adhesive sheet for semiconductor processing of the present embodiment to the surface of the semiconductor wafer with the adhesive layer as the attaching surface; With the surface coating layer side of the adhesive sheet for semiconductor processing attached to the semiconductor wafer fixed by a support device, the back surface of the semiconductor wafer is ground to form a plurality of semiconductor chips starting from the grooves or modified regions.
• the method for manufacturing a semiconductor device includes: Furthermore, the method for manufacturing a semiconductor device of this embodiment may include a peeling step of peeling the adhesive sheet for semiconductor processing of this embodiment from the plurality of semiconductor chips after the grinding and singulation steps.
• the method of manufacturing a semiconductor device having the above step a corresponds to the pre-dicing method
• the method of manufacturing a semiconductor device having the step b corresponds to the stealth pre-dicing method.
• Examples of semiconductor wafers used in the manufacturing method of this embodiment include silicon wafers, gallium arsenide wafers, gallium nitride wafers, silicon carbide wafers, glass wafers, and sapphire wafers. Among these, silicon wafers are preferred. Circuits such as wiring, capacitors, diodes, and transistors are usually formed on the surface of a semiconductor wafer. These circuits can be formed by conventionally known methods such as etching and lift-off. The thickness of the semiconductor wafer before grinding is not particularly limited, but is usually 500 to 1,000 ⁇ m. Each step of the method for manufacturing the semiconductor device of this embodiment will be described in detail below.
• the planned dividing line forming step is a step a of forming grooves on the surface of the semiconductor wafer, or a step b of forming a modified region inside the semiconductor wafer from the front surface or the back surface of the semiconductor wafer.
• Step a is a step of forming grooves on the surface of the semiconductor wafer, and is performed before sticking the adhesive sheet on the surface of the semiconductor wafer.
• the groove formed in the surface of the semiconductor wafer in step a is a groove shallower than the thickness of the semiconductor wafer.
• the semiconductor wafer is back-ground to reach the grooves formed in step a, and divided into a plurality of semiconductor chips. Therefore, in step a, grooves are formed along dividing lines along which the semiconductor wafer is divided into individual semiconductor chips.
• the grooves can be formed by dicing using a conventionally known wafer dicing device or the like.
• Step b is a step of forming a modified region inside the semiconductor wafer from the front surface or the back surface of the semiconductor wafer, and may be performed before or after attaching the adhesive sheet to the surface of the semiconductor wafer.
• a modified region is formed inside the semiconductor wafer by irradiating a laser focused inside the semiconductor wafer.
• the modified region is an embrittled portion of the semiconductor wafer, which is thinned by grinding the back surface of the semiconductor wafer or broken by the application of grinding force, and the semiconductor wafer is divided into individual semiconductor chips. This is the area that becomes the starting point for conversion. Therefore, the modified regions are formed along dividing lines along which the semiconductor wafer is divided into individual semiconductor chips.
• Laser irradiation may be performed from the front surface side of the semiconductor wafer or from the back surface side.
• the semiconductor wafer may be irradiated with the laser through the adhesive sheet.
• the sheet attaching step is a step of attaching an adhesive sheet to the surface of the semiconductor wafer after the step a or before or after the step b using the adhesive layer as the attaching surface.
• the method of attaching the adhesive sheet is not particularly limited, and for example, a conventionally known method using a laminator or the like can be applied.
• the back surface of the semiconductor wafer is ground in a state where the surface coating layer side of the adhesive sheet attached to the semiconductor wafer is fixed by a support device, and a plurality of pieces are formed with the grooves or modified regions as starting points.
• This is the step of singulating into semiconductor chips.
• the semiconductor wafer to which the adhesive sheet is attached and the grooves or modified regions are formed is fixed by a supporting device on the surface coating layer side of the adhesive sheet.
• the support device is not particularly limited, a device such as a chuck table that sucks and holds a fixed object is preferable.
• the back surface of the fixed semiconductor wafer is ground to singulate the semiconductor wafer into a plurality of semiconductor chips.
• the backside grinding is performed by grinding the semiconductor wafer to at least the position where the ground surface reaches the bottom of the groove.
• the grooves become cuts penetrating the wafer, and the semiconductor wafer is divided by the cuts into individual semiconductor chips.
• the ground surface may reach the modified region, but strictly does not have to reach the modified region. That is, the semiconductor wafer may be ground from the modified region to a position close to the modified region so that the semiconductor wafer is broken into individual semiconductor chips starting from the modified region. For example, after grinding the semiconductor wafer to a position close to the modified region without singulating the semiconductor wafer, a pick-up tape is attached to the semiconductor wafer, and the pick-up tape is stretched to singulate into semiconductor chips. may
• the shape of the individualized semiconductor chips may be a square or an elongated shape such as a rectangle.
• the thickness of the singulated semiconductor chips is not particularly limited, but is preferably 5 to 100 ⁇ m, more preferably 7 to 70 ⁇ m, still more preferably 10 to 45 ⁇ m.
• the chip size of the singulated semiconductor chips is not particularly limited, but is preferably less than 50 mm 2 , more preferably less than 30 mm 2 , still more preferably less than 10 mm 2 .
• the peeling step is a step of peeling off the adhesive sheet from the plurality of semiconductor chips after the grinding and singulation steps.
• the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is formed from an energy ray-curable pressure-sensitive adhesive
• the pressure-sensitive adhesive is cured by irradiation with energy rays to reduce the peel strength of the pressure-sensitive adhesive layer, and then the pressure-sensitive adhesive sheet is removed. exfoliate.
• a pick-up tape may be used when peeling off the adhesive sheet.
• a pickup tape is composed of, for example, a substrate and an adhesive sheet provided with an adhesive layer provided on one surface of the substrate.
• the pick-up tape When using a pick-up tape, first, the pick-up tape is attached to the rear surface side of the singulated semiconductor wafer, and the position and direction are aligned so that pick-up is possible. At this time, it is preferable that the ring frame arranged on the outer peripheral side of the semiconductor wafer is also adhered to the pick-up tape, and the outer peripheral edge of the pick-up tape is fixed to the ring frame. Next, the adhesive sheet is peeled off from the plurality of semiconductor chips fixed on the pickup tape. After that, a plurality of semiconductor chips on the pickup tape may be picked up and fixed on a substrate or the like to manufacture a semiconductor device.
• Mass average molecular weight (Mw) The mass average molecular weight (Mw) was measured using a gel permeation chromatograph (manufactured by Tosoh Corporation, product name "HLC-8220") under the following conditions, and calculated in terms of standard polystyrene. (Measurement condition) ⁇ Column: "TSK guard column HXL-H”"TSK gel GMHXL (x 2)""TSK gel G2000HXL” (both manufactured by Tosoh Corporation) ⁇ Column temperature: 40°C ⁇ Developing solvent: tetrahydrofuran ⁇ Flow rate: 1.0 mL/min
• the total thickness of the pressure-sensitive adhesive sheet, the thickness of each layer, and the thickness of a test piece prepared from these were measured using a constant-pressure thickness gauge (manufactured by Teclock Co., Ltd., trade name "PG-02"). At this time, arbitrary 10 points were measured and an average value was calculated.
• the total thickness of the adhesive sheet is a value obtained by measuring the thickness of the adhesive sheet with a release sheet and subtracting the thickness of the release sheet from the measured thickness.
• the thickness of the buffer layer is a value obtained by subtracting the thickness of the base material from the thickness of the base material with the buffer layer.
• the thickness of the surface coat layer is a value obtained by subtracting the thickness of the release sheet from the thickness of the surface coat layer with the release sheet.
• the thickness of the pressure-sensitive adhesive layer is the total thickness of the pressure-sensitive adhesive sheet minus the thickness of the surface coat layer, the buffer layer and the substrate.
• grinding dust adhering part means an island-shaped grinding dust adhering part formed by drying droplets of grinding water adhering to the surface coat layer.
• D Grinding dust adheres to the entire surface of the surface coat layer.
• Production example 2 An acrylic polymer was obtained by copolymerizing 52 parts by mass of n-butyl acrylate, 20 parts by mass of methyl methacrylate, and 28 parts by mass of 2-hydroxyethyl acrylate. Next, 2-methacryloyloxyethyl isocyanate is reacted so as to be added to 90 mol% of all hydroxyl groups of the acrylic polymer to obtain an energy ray-curable polymer having a mass average molecular weight (Mw) of 500,000. An acrylic resin was obtained.
• Mw mass average molecular weight
• a coating liquid for a coat layer was prepared.
• 100 parts by mass of the resin shown in Table 1 and 30 parts by mass of silica filler (manufactured by Nissan Chemical Industries, Ltd., trade name "Snowtex (registered trademark) UP") were added so that the active ingredient concentration was 5% by mass.
• a coating liquid for a surface coating layer was prepared by dissolving and dispersing in toluene.
• buffer layer-forming composition 40 parts by mass of urethane acrylate oligomer obtained in Production Example 1, 40 parts by mass of isobornyl acrylate, 20 parts by mass of 2-hydroxy-3-phenoxypropyl acrylate, photopolymerization initiator 2.0 parts by mass of 1-hydroxycyclohexylphenyl ketone and 0.2 parts by mass of a phthalocyanine pigment were blended to prepare a composition for forming a buffer layer.
• a laminate having a buffer layer, a substrate and an adhesive layer in this order is obtained by attaching the adhesive layer of the adhesive layer-attached release sheet to the surface of the cushioning layer-attached substrate on which the cushioning layer is not provided. made.
• the coating liquid for the surface coating layer obtained above was applied to the release-treated surface of a release sheet (trade name “SP-PET381031” manufactured by Lintec Corporation) with a Meyer bar so that the thickness after drying was 2 ⁇ m. After coating, the surface coating layer with a release sheet was prepared by heating and drying.
• the surface coat layer of the release sheet-attached surface coat layer was adhered to the surface of the buffer layer of the laminate to obtain a pressure-sensitive adhesive sheet having a surface coat layer, a buffer layer, a substrate and a pressure-sensitive adhesive layer in this order. .
• Table 1 shows the evaluation results of the adhesive sheets obtained in each example and comparative example.
• Maleic anhydride-modified polyolefin resin propylene-butene-maleic anhydride copolymer, maleic anhydride modification rate: 1.5% by mass, weight average molecular weight (Mw): 75,000, heteroatom content: 0.735 % by mass, manufactured by Toyobo Co., Ltd., trade name "Toyotac (registered trademark) PMA-L"
• Ethylene-cyclic olefin copolymer ethylene-tetracyclododecene copolymer, content of structural units derived from tetracyclododecene: 20 to 32 mol%, heteroatom content: 5.2% by mass, Mitsui Chemical Co., Ltd., trade name “APEL (registered trademark) APL6509T”
• Ethylene-vinyl acetate copolymer Vinyl acetate content: 14% by mass, heteroatom content: 0% by mass, manufactured by Toyobo Co., Ltd.

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