WO2023188272A1 - Adhesive tape for semiconductor processing - Google Patents

Adhesive tape for semiconductor processing Download PDF

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Publication number
WO2023188272A1
WO2023188272A1 PCT/JP2022/016521 JP2022016521W WO2023188272A1 WO 2023188272 A1 WO2023188272 A1 WO 2023188272A1 JP 2022016521 W JP2022016521 W JP 2022016521W WO 2023188272 A1 WO2023188272 A1 WO 2023188272A1
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WO
WIPO (PCT)
Prior art keywords
buffer layer
semiconductor wafer
meth
semiconductor
adhesive tape
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PCT/JP2022/016521
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French (fr)
Japanese (ja)
Inventor
智 金子
翔斗 鳥越
和幸 田村
裕也 長谷川
Original Assignee
リンテック株式会社
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Application filed by リンテック株式会社 filed Critical リンテック株式会社
Priority to PCT/JP2022/016521 priority Critical patent/WO2023188272A1/en
Priority to TW112109721A priority patent/TW202403853A/en
Publication of WO2023188272A1 publication Critical patent/WO2023188272A1/en

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    • 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

Definitions

  • the present invention relates to an adhesive tape for semiconductor processing. More specifically, the present invention relates to an adhesive tape for semiconductor processing, a method of using the adhesive tape for semiconductor processing, and a method of manufacturing a semiconductor device using the adhesive tape for semiconductor processing.
  • DBG dicing before grinding
  • a modified region is formed inside the semiconductor wafer using a laser or plasma, etc., without forming a groove on the front surface side of the semiconductor wafer, and the semiconductor wafer is
  • a method of obtaining semiconductor chips by dividing into individual pieces has also been proposed. In this method, a semiconductor wafer is cut in the crystal direction starting from the modified region. Therefore, occurrence of chipping can be reduced more than in DBG using a dicing blade. As a result, a semiconductor chip with excellent bending strength can be obtained, and the semiconductor chip can be made even thinner.
  • an adhesive tape for semiconductor processing As such an adhesive tape for semiconductor processing, an adhesive tape for semiconductor processing has been proposed, for example, which has a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order (for example, a patent (See Reference 1, etc.).
  • semiconductor chip cracks chipping and breakage of semiconductor chips (hereinafter referred to as "semiconductor chip cracks”) may occur due to cut dust generated when cutting adhesive tape for semiconductor processing.
  • semiconductor chip cracks chipping and breakage of semiconductor chips
  • the inventors of the present invention investigated the main causes of cut dust generation. As a result, when cutting adhesive tape for semiconductor processing with a blade, the buffer layer is rubbed due to contact between the blade and the buffer layer, causing twisting of the resin that makes up the buffer layer and roughening of the cut surface. It was discovered that cut dust was generated.
  • an object of the present invention is to provide an adhesive tape for semiconductor processing that has excellent cuttability with a blade.
  • the present invention relates to the following [1] to [7].
  • [1] It has a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order, An adhesive tape for semiconductor processing, wherein the buffer layer satisfies both the following requirements ( ⁇ ) and the following requirements ( ⁇ ).
  • - Requirement ( ⁇ ) The breaking energy of the buffer layer at 23° C. is 15 MJ/m 3 or more.
  • the stress increase gradient ⁇ 80-100 is 30 MPa or more.
  • a method of using the adhesive tape for semiconductor processing according to any one of [1] to [3] above comprising: A method of use in which the adhesive tape for semiconductor processing is affixed to the surface of the semiconductor wafer and the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer when back grinding the semiconductor wafer.
  • a step of attaching the adhesive tape for semiconductor processing according to any one of [1] to [3] above to the surface of a semiconductor wafer, and cutting the adhesive tape for semiconductor processing along the outer periphery of the semiconductor wafer S1 A method for manufacturing a semiconductor device.
  • a method for manufacturing a semiconductor device including the following step (S2).
  • Step (S2) Step of grinding the semiconductor wafer from the back side [7]
  • a method for manufacturing a semiconductor device including the following step (S3).
  • - Step (S3) Step of dicing the semiconductor wafer into individual pieces [8]
  • the semiconductor wafer As the semiconductor wafer, a semiconductor wafer with grooves formed on the front side is used, In the step (S2), the semiconductor wafer is singulated into a plurality of chips using the groove as a starting point.
  • the semiconductor wafer As the semiconductor wafer, a semiconductor wafer having a modified region formed therein is used, or a modified region is formed inside the semiconductor wafer after the step (S1), In the step (S2), the semiconductor wafer is singulated into a plurality of chips starting from the modified region.
  • an adhesive tape for semiconductor processing that has excellent cuttability with a blade.
  • FIG. 1 is a schematic cross-sectional view showing an example of the adhesive tape for semiconductor processing of the present invention.
  • FIG. 2 is a process schematic diagram of a method for manufacturing a semiconductor device according to the present invention. It is a figure which shows the analytical model by Abaqus.
  • Example 1sim in "Evaluation of cutting performance by blade (1): Evaluation by simulation”. and Comparative Example 3sim. This is an analysis image by Abaqus.
  • SEM scanning electron microscope
  • (meth)acrylate is a concept that includes both “acrylate” and “methacrylate,” and the same applies to other similar terms.
  • (meth)acryloyl group is a concept that includes both “acryloyl group” and “methacryloyl group.”
  • the weight average molecular weight and number average molecular weight are polystyrene equivalent values measured by gel permeation chromatography (GPC).
  • the adhesive tape for semiconductor processing of the present invention has a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order.
  • the buffer layer satisfies both the following requirement ( ⁇ ) and the following requirement ( ⁇ ).
  • - Requirement ( ⁇ ) The breaking energy of the buffer layer at 23° C. is 15 MJ/m 3 or more.
  • ⁇ Requirement ( ⁇ ) When the buffer layer is subjected to a tensile test at a temperature of 23°C, the strain ( ⁇ 80 ) that is 80% of the breaking strain ( ⁇ 100 ) increases to the breaking strain ( ⁇ 100 ). , the stress increase gradient ⁇ 80-100 is 30 MPa or more.
  • FIG. 1 shows a schematic cross-sectional view of one embodiment of the adhesive tape for semiconductor processing of the present invention.
  • the adhesive tape 1 for semiconductor processing shown in FIG. 1 has a laminated structure in which a buffer layer 11, a base material 12, and an adhesive layer 13 are laminated in this order.
  • a buffer layer 11, a base material 12, and an adhesive layer 13 are directly laminated without using any other layer. Therefore, the adhesive tape 1 for semiconductor processing shown in FIG. 1 is composed of only the buffer layer 11, the base material 12, and the adhesive layer 13.
  • the adhesive tape 1 for semiconductor processing is not necessarily limited to such a form.
  • another layer may be provided between the buffer layer 11 and the base material 12, or between the base material 12 and the adhesive layer 13, if necessary.
  • the other layers include a primer layer, a layer for embedding bumps formed on the circuit surface of the wafer, and the like.
  • a release sheet may be laminated on the surface of the adhesive layer 13 to protect the adhesive layer 13 until use.
  • a coating layer may be provided on the surface of the buffer layer 11.
  • the buffer layer 11, the base material 12, and the adhesive layer 13 each have a single layer structure in FIG. 1, they may have a multilayer structure.
  • adheresive tape for semiconductor processing may be simply abbreviated as “adhesive tape.”
  • the buffer layer has a function of alleviating stress during backside grinding of the semiconductor wafer and preventing cracks and chips from occurring in the semiconductor wafer.
  • adhesive tape is attached to the semiconductor wafer, and after the adhesive tape is cut along the outer periphery of the semiconductor wafer, the semiconductor wafer is placed on a chuck table via the adhesive tape and the back surface is ground. Having the layer helps the semiconductor wafer to be properly held on the chuck table.
  • the adhesive tape having a buffer layer has great advantages.
  • the buffer layer is softer than the base material. Specifically, when cutting the adhesive tape, the resin of the buffer layer may become twisted, resulting in rough cut surfaces and generation of cut dust.
  • the present inventors found that it is effective to suppress cut dust by increasing the cutting performance of the adhesive tape blade and suppressing the roughness of the cut surface of the buffer layer.
  • the above requirement ( ⁇ ) and the above requirement ( ⁇ ) were identified.
  • the breaking energy of the buffer layer at 23° C. is preferably 17 MJ/m 3 or more, more preferably 22 MJ/m 3 or more, and even more preferably is 27 MJ/m 3 or more. Further, from the viewpoint of preventing blade wear, the breaking energy of the buffer layer at 23° C. is preferably 150 MJ/m 3 or less.
  • the breaking energy of the buffer layer at 23°C is determined by the breaking point in the stress-strain diagram, which is a diagram of stress and strain, obtained by a tensile test at 23°C based on JIS K7161:1994 and JIS K7127:1999. This is the value obtained by integrating up to . Strain can be determined by initial test piece length (mm) x elongation (%). In addition, the breaking stress and breaking strain mentioned later are the stress and strain at the time of breaking (breaking point) in the above-mentioned tensile test, respectively.
  • the stress increase gradient ⁇ 80-100 of the buffer layer is less than 30 MPa, the buffer layer cannot be cut easily by the blade.
  • the stress increase gradient ⁇ 80-100 is preferably 50 MPa or more, more preferably 70 MPa or more, still more preferably 75 MPa or more, and even more preferably is 80 MPa or more, even more preferably 85 MPa or more, even more preferably 90 MPa or more, even more preferably 95 MPa or more, even more preferably 100 MPa or more.
  • the stress increase gradient ⁇ 80-100 is usually 200 MPa or less.
  • the buffer layer is a soft layer compared to the base material.
  • the elastic modulus of the buffer layer at 23°C is preferably 1,200 MPa or less, more preferably 1,000 MPa or less, and even more preferably 800 MPa. Below, it is still more preferably 700 MPa or less, still more preferably 500 MPa or less.
  • the fracture stress of the buffer layer is preferably 30 MPa or more, more preferably 50 MPa or more, still more preferably 55 MPa or more, and even more preferably It is 60 MPa or more.
  • the breaking strain ( ⁇ 100 ) of the buffer layer is preferably 0.50 or more, more preferably 1.0 or more, and even more preferably 1.1 or more. , even more preferably 1.2 or more, even more preferably 1.3 or more, even more preferably 1.4 or more.
  • the thickness of the buffer layer is preferably 1 ⁇ m to 100 ⁇ m, more preferably 5 ⁇ m to 80 ⁇ m, and even more preferably 10 ⁇ m to 60 ⁇ m, from the viewpoint of appropriately relieving stress during backside grinding of a semiconductor wafer.
  • the buffer layer can be used without particular restrictions as long as it has the function of appropriately relieving stress during backside grinding of a semiconductor wafer and satisfies the above requirements ( ⁇ ) and ( ⁇ ).
  • the buffer layer is preferably a cured product of a composition for forming a buffer layer containing an energy ray polymerizable compound.
  • each component contained in the layer formed from the composition for forming a buffer layer containing an energy beam polymerizable compound will be explained in order.
  • a composition for forming a buffer layer containing an energy beam polymerizable compound is cured by being irradiated with energy rays.
  • energy ray refers to electromagnetic waves or charged particle beams that have energy quanta. Examples of energy rays include ultraviolet rays, radiation, electron beams, and the like.
  • the ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, fusion lamp, xenon lamp, black light, or LED lamp as an ultraviolet source.
  • the electron beam can be generated by an electron beam accelerator or the like.
  • the composition for forming a buffer layer containing an energy beam polymerizable compound preferably contains urethane (meth)acrylate (a1).
  • the composition for forming a buffer layer can easily adjust the breaking energy of the buffer layer to the above range.
  • the composition for forming a buffer layer also contains a polymerizable compound (a2) having an alicyclic group or a heterocyclic group having 6 to 20 ring atoms and a polymerizable compound having a functional group ( It is more preferable to contain one or more selected from a3).
  • composition for forming a buffer layer may contain a polyfunctional polymerizable compound (a4) in addition to the components (a1) to (a3) described above.
  • composition for forming a buffer layer preferably contains a photopolymerization initiator, and may contain other additives and resin components within a range that does not impair the effects of the present invention.
  • a photopolymerization initiator e.g., a photopolymerization initiator
  • Urethane (meth)acrylate (a1) is a compound having at least a (meth)acryloyl group and a urethane bond, and has the property of being polymerized and cured by energy ray irradiation.
  • Urethane (meth)acrylate (a1) is an oligomer or a polymer, and in this embodiment, an oligomer is preferred.
  • urethane (meth)acrylate (a1) is also referred to as "component (a1)."
  • the weight average molecular weight (Mw) of component (a1) is preferably from 1,000 to 100,000, more preferably from 2,000 to 60,000, even more preferably from 2,000 to less than 10,000.
  • the number of (meth)acryloyl groups (hereinafter also referred to as "functional group number") in component (a1) may be monofunctional, bifunctional, or trifunctional or more, but monofunctional or difunctional is preferable.
  • Component (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 hydroxyl group.
  • the component (a1) may be used alone or in combination of two or more.
  • the polyol compound serving as a raw material for component (a1) 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, and polycarbonate polyols. Among these, polyester type polyols or polycarbonate type polyols are preferred.
  • the polyol compound may be any of bifunctional diols, trifunctional triols, and tetrafunctional or higher functional polyols, but bifunctional diols are preferred, and polyester diols or polycarbonate diols are more preferred.
  • polyvalent isocyanate compounds include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; isophorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and dicyclohexylmethane-2 , 4'-diisocyanate, ⁇ , ⁇ '-diisocyanate, alicyclic diisocyanates such as dimethylcyclohexane; 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, toridine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene.
  • aromatic diisocyanates such as 1,5-diisocyanate. Among these, isophorone diis
  • Urethane (meth)acrylate (a1) can be obtained by reacting a (meth)acrylate having a hydroxy group with a terminal isocyanate urethane prepolymer obtained by reacting the above-mentioned polyol compound and a polyvalent isocyanate compound.
  • the (meth)acrylate having a hydroxy group is not particularly limited as long as it is a compound having a hydroxy group and a (meth)acryloyl group in at least one molecule.
  • (meth)acrylates having a hydroxy group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 4-hydroxycyclohexyl (meth)acrylate.
  • Acrylate 5-hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, etc.
  • hydroxyalkyl (meth)acrylate hydroxy group-containing (meth)acrylamide such as N-methylol (meth)acrylamide; reaction obtained by reacting diglycidyl ester of vinyl alcohol, vinylphenol, or bisphenol A with (meth)acrylic acid things; etc.
  • hydroxyalkyl (meth)acrylate is preferred, and 2-hydroxyethyl (meth)acrylate is more preferred.
  • Conditions for reacting the terminal isocyanate urethane prepolymer and the (meth)acrylate having a hydroxyl group include conditions for reacting at 60° C. to 100° C. for 1 hour to 4 hours in the presence of a solvent and catalyst added as necessary. is preferred.
  • the content of component (a1) in the composition for forming a buffer layer is preferably 10% by mass to 80% by mass, more preferably 30% by mass, based on the total amount (100% by mass) of the composition for forming a buffer layer. ⁇ 80% by weight, more preferably 40% by weight ⁇ 80% by weight.
  • the polymerizable compound (a2) having an alicyclic group or a heterocyclic group having 6 to 20 ring atoms (hereinafter also referred to as "component (a2")) is an alicyclic group or a heterocyclic group having 6 to 20 ring atoms. It is a polymerizable compound having a group, more preferably a compound having at least one (meth)acryloyl group, more preferably a compound having one (meth)acryloyl group.Component (a2) By using it, the film-forming properties of the resulting composition for forming a buffer layer can be improved.
  • component (a3) there is some overlap between the definition of component (a2) and the definition of component (a3) described below, but the overlap is included in component (a3).
  • a compound having at least one (meth)acryloyl group, an alicyclic group or a heterocyclic group having 6 to 20 ring atoms, and a functional group such as a hydroxyl group, an epoxy group, an amide group, or an amino group may be used as a component.
  • the compound is included in component (a3) in the present invention.
  • the number of ring atoms of the alicyclic group or heterocyclic group contained in component (a2) is preferably 6 to 20, more preferably 6 to 18, and still more preferably 6 to 16.
  • Examples of atoms forming the ring structure of the heterocyclic group include carbon atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.
  • the number of ring-forming atoms refers to the number of atoms that make up the ring itself of a compound with a structure in which atoms are bonded in a ring, and refers to atoms that do not make up a ring (for example, hydrogen atoms bonded to atoms that make up a ring).
  • atoms included in the substituent are not included in the number of ring atoms.
  • component (a2) examples include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxy (meth)acrylate, cyclohexyl (meth)acrylate, Alicyclic group-containing (meth)acrylates such as adamantane (meth)acrylate; heterocyclic group-containing (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate and morpholine (meth)acrylate; and the like.
  • the component (a2) may be used alone or in combination of two or more.
  • isobornyl (meth)acrylate is preferred, and among the heterocyclic group-containing (meth)acrylates, tetrahydrofurfuryl (meth)acrylate is preferred.
  • the content of component (a2) in the composition for forming a buffer layer is preferably based on the total amount (100% by mass) of the composition for forming a buffer layer. is 10% by mass to 80% by mass, more preferably 20% by mass to 70% by mass.
  • the polymerizable compound (a3) having a functional group (hereinafter also referred to as "component (a3)”) is a polymerizable compound containing a functional group such as a hydroxyl group, an epoxy group, an amide group, an amino group, and further, A compound having at least one (meth)acryloyl group is preferable, and a compound having one (meth)acryloyl group is more preferable.
  • Component (a3) has good compatibility with component (a1), making it easy to adjust the viscosity of the buffer layer forming composition to an appropriate range.
  • component (a3) examples include hydroxyl group-containing (meth)acrylates, epoxy group-containing compounds, amide group-containing compounds, amino group-containing (meth)acrylates, and the like.
  • hydroxyl group-containing (meth)acrylates examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxy Butyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenylhydroxypropyl (meth)acrylate, cyclohexanol (meth)acrylate, 4-tert-butylcyclohexanol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, etc. Can be mentioned.
  • Examples of epoxy group-containing compounds include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and allylglycidyl ether.
  • Group-containing (meth)acrylates are preferred.
  • Examples of the amide group-containing compound include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, and N-methylol(meth)acrylamide.
  • Examples of the amino group-containing (meth)acrylate include primary amino group-containing (meth)acrylate, secondary amino group-containing (meth)acrylate, and tertiary amino group-containing (meth)acrylate.
  • hydroxyl group-containing (meth)acrylates are preferred, and hydroxyl group-containing (meth)acrylates having an aromatic ring such as phenylhydroxypropyl (meth)acrylate, cyclohexanol (meth)acrylate, 4-tert-butylcyclohexanol acrylate, etc.
  • Hydroxyl group-containing (meth)acrylates having an alicyclic ring are more preferred, and hydroxyl group-containing (meth)acrylates having an alicyclic ring are even more preferred.
  • the number of carbon atoms forming the alicyclic ring is preferably 6 to 20, more preferably 6 to 18, and still more preferably 6 to 16.
  • component (a3) may be used singly or in combination of two or more.
  • the content of component (a3) in the composition for forming a buffer layer is determined from the viewpoint of easily adjusting the breaking energy of the buffer layer within the above range, and from the viewpoint of forming the buffer layer. From the viewpoint of easily improving the film formability of the composition for forming a buffer layer, preferably 5% to 50% by mass, more preferably 10% to 40% by mass, based on the total amount (100% by mass) of the composition for forming a buffer layer. % by mass, more preferably 20% by mass to 30% by mass.
  • the content ratio of component (a2) and component (a3) in the composition for forming a buffer layer [(a2)/ (a3)] is preferably 0.5 to 3.0, more preferably 1.0 to 3.0, even more preferably 1.3 to 3.0, even more preferably 1.5 to 3.0, in terms of mass ratio. It is 2.8.
  • the composition for forming a buffer layer preferably contains a component (a3), and the component (a3) is an alicyclic A hydroxyl group-containing (meth)acrylate having a formula ring is preferable.
  • the polyfunctional polymerizable compound (a4) (hereinafter also referred to as "component (a4)”) refers to a compound having two or more photopolymerizable unsaturated groups.
  • the photopolymerizable unsaturated group is a functional group containing a carbon-carbon double bond, and includes, for example, a (meth)acryloyl group, a vinyl group, an allyl group, a vinylbenzyl group, and the like. Two or more types of photopolymerizable unsaturated groups may be used in combination.
  • a three-dimensional network structure (crosslinked structure) is formed.
  • component (a4) there is some overlap between the definition of component (a4) and the definitions of component (a2) and component (a3) described above, but the overlap is included in component (a4).
  • a compound having an alicyclic group or a heterocyclic group having 6 to 20 ring atoms and having two or more (meth)acryloyl groups is included in the definition of both component (a4) and component (a2).
  • the compound is included in component (a4).
  • compounds containing functional groups such as hydroxyl groups, epoxy groups, amide groups, amino groups, etc., and having two or more (meth)acryloyl groups are included in the definition of both component (a4) and component (a3).
  • the compound is included in component (a4).
  • the number of photopolymerizable unsaturated groups (number of functional groups) in the polyfunctional polymerizable compound is preferably 2 to 10, more preferably 3 to 6.
  • the weight average molecular weight of component (a4) is preferably 30 to 40,000, more preferably 100 to 10,000, and still more preferably 200 to 1,000.
  • component (a4) include diethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and 1,6-hexane.
  • dipentaerythritol hexa(meth)acrylate is preferred.
  • component (a4) may be used individually by 1 type, and may be used in combination of 2 or more types.
  • the content of component (a4) in the composition for forming a buffer layer is preferably 0% by mass to 40% by mass, more preferably 0% by mass, based on the total amount (100% by mass) of the composition for forming a buffer layer. ⁇ 20% by weight, more preferably 0% by weight ⁇ 15% by weight.
  • the composition for forming a buffer layer may contain a polymerizable compound (a5) (hereinafter referred to as "component (a5)”), as long as the effects of the present invention are not impaired. ) may also be included.
  • Component (a5) is, for example, an alkyl (meth)acrylate having an alkyl group having 1 to 20 carbon atoms; styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N-vinylformamide, N-vinylpyrrolidone, N-vinylcaprolactam, etc. Vinyl compounds: etc.
  • component (a5) may be used alone or in combination of two or more.
  • the content of component (a5) in the composition for forming a buffer layer is preferably 0% by mass to 20% by mass, more preferably 0% to 10% by mass, even more preferably 0% to 5% by mass, and more preferably 0% to 10% by mass. More preferably, it is 0% to 2% by mass.
  • the composition for forming a buffer layer preferably further contains a photopolymerization initiator from the viewpoint of shortening the polymerization time by light irradiation and reducing the amount of light irradiation when forming the buffer layer.
  • photopolymerization initiators examples include benzoin compounds, acetophenone compounds, acylphosphinoxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and photosensitizers such as amines and quinones, and more.
  • 1-hydroxycyclohexyl phenyl ketone 2-hydroxy-2-methyl-1-phenyl-propan-1-one
  • benzoin benzoin methyl ether
  • benzoin ethyl ether benzoin isopropyl ether
  • benzylphenyl sulfide examples include tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and the like.
  • These photopolymerization initiators may be used alone or in combination of two or more.
  • the content of the photopolymerization initiator in the composition for forming a buffer layer is preferably 0.05 parts by mass to 15 parts by mass, more preferably 0.1 parts by mass, based on 100 parts by mass of the total amount of energy ray polymerizable compounds.
  • the amount is from 10 parts by weight, more preferably from 0.3 parts to 5 parts by weight.
  • the composition for forming a buffer layer may contain other additives to the extent that the effects of the present invention are not impaired.
  • other additives include one or more selected from antistatic agents, antioxidants, softeners (plasticizers), fillers, rust preventives, pigments, dyes, and the like.
  • the content of each additive in the composition for forming a buffer layer is preferably 0.01 parts by mass to 6 parts by mass based on 100 parts by mass of the total amount of energy ray polymerizable compounds. parts, more preferably 0.1 parts to 3 parts by weight.
  • the composition for forming a buffer layer may contain a resin component within a range that does not impair the effects of the present invention.
  • the resin component include polyene/thiol resins, polyolefin resins such as polybutene, polybutadiene, and polymethylpentene, and thermoplastic resins such as styrene copolymers.
  • the content of these resin components in the composition for forming a buffer layer is preferably 0% to 20% by mass, more preferably 0% to 10% by mass, even more preferably 0% to 5% by mass, and more preferably 0% to 10% by mass. More preferably, it is 0% to 2% by mass.
  • a buffer layer formed from a composition for forming a buffer layer containing an energy ray polymerizable compound is obtained by polymerizing and curing the composition for forming a buffer layer having the above composition by irradiation with energy rays. That is, the buffer layer is a cured product of the composition for forming a buffer layer. Therefore, the buffer layer contains polymerized units derived from component (a1). Moreover, it is preferable that the buffer layer contains at least one of a polymerized unit derived from component (a2) and a polymerized unit derived from component (a3). Furthermore, it may contain at least one of the polymerized units derived from component (a4) and the polymerized units derived from component (a5).
  • the content ratio of each polymerized unit in the buffer layer usually corresponds to the ratio (preparation ratio) of each component constituting the composition for forming a buffer layer.
  • the buffer layer contains component (a1).
  • ) Contains 10% to 70% by mass of polymerized units derived from.
  • the buffer layer contains component (a2).
  • ) contains 10% to 80% by mass of polymerized units derived from. The same applies to components (a3) to (a5).
  • the breaking energy at 23° C. of the buffer layer is determined by, for example, the weight average molecular weight of the above-mentioned urethane (meth)acrylate (a1). It can be controlled by adjusting the thickness of the buffer layer and selecting the monomer species appropriately.
  • the base material functions as a support for the adhesive tape.
  • the base material include various resin films.
  • polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, norbornene resin
  • Polyolefins such as ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester copolymers, etc.
  • polyvinyl chloride vinyl chloride copolymers
  • Polyvinyl chloride such as coalescence
  • polyester such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, fully aromatic polyester
  • the base material may be a single-layer resin film made of one or more resins selected from these resins, or may be a laminated film in which two or more of these resin films are laminated.
  • the base material since the base material is harder than the buffer layer, it is less likely that the cut surface will become rough when cut with a blade compared to the buffer layer, but from the viewpoint of making the base material more easily cut by the blade , the base material preferably satisfies the following requirement ( ⁇ ).
  • ⁇ - Requirement ( ⁇ ): The product of the breaking strain ( ⁇ 100 ) at a temperature of 23°C and the breaking stress ( ⁇ 100 ) at a temperature of 23°C is 60 MPa or more.
  • the elastic modulus of the base material at 23° C. is preferably 200 MPa or more, more preferably 500 MPa or more, and still more preferably 1,000 MPa or more. Moreover, it is preferably 30,000 MPa or less, more preferably 10,000 MPa or less, and still more preferably 6,000 MPa or less.
  • the thickness of the base material is not particularly limited, but is preferably 110 ⁇ m or less, more preferably 15 ⁇ m to 110 ⁇ m, and even more preferably 20 ⁇ m to 105 ⁇ m. By setting the thickness of the base material to 110 ⁇ m or less, it becomes easier to control the peeling force of the adhesive tape. Further, by setting the thickness of the base material to 15 ⁇ m or more, the base material can easily function as a support for the adhesive tape.
  • the base material may also contain plasticizers, lubricants, infrared absorbers, ultraviolet absorbers, fillers, colorants, antistatic agents, antioxidants, catalysts, etc., as long as they do not impair the effects of the present invention. good.
  • the base material may be transparent or opaque, and may be colored or vapor-deposited as desired.
  • at least one surface of the base material may be subjected to adhesive treatment such as corona treatment in order to improve adhesion to at least one of the buffer layer and the adhesive layer.
  • the base material may include the resin film described above and an easily adhesive layer coated on at least one surface of the resin film.
  • the composition for forming an easily adhesive layer that forms the easily adhesive layer is not particularly limited, but examples thereof include compositions containing polyester resins, urethane resins, polyester urethane resins, acrylic resins, and the like.
  • the composition for forming an easily adhesive layer may contain a crosslinking agent, a photopolymerization initiator, an antioxidant, a softener (plasticizer), a filler, a rust preventive, a pigment, a dye, etc., as necessary. good.
  • the thickness of the adhesive layer is preferably 0.01 ⁇ m to 10 ⁇ m, more preferably 0.03 ⁇ m to 5 ⁇ m.
  • the thickness of the easily bonding layer in the Examples of the present application is smaller than the thickness of the base material, the thickness of the resin film having the easily bonding layer and the thickness of the base material are substantially the same.
  • the material of the easily bonding layer is soft, its influence on the elastic modulus is small, and the elastic modulus of the base material is substantially the same as the Young's modulus of the resin film even when the base material has the easily bonding layer.
  • the product of the breaking strain ( ⁇ 100 ) at a temperature of 23°C and the breaking stress ( ⁇ 100 ) at a temperature of 23°C, which is defined by the requirement ( ⁇ ), and the elastic modulus of the base material are determined by the selection of the resin composition, the plasticity It can be controlled by adding agents, stretching conditions during resin film production, etc. Specifically, when a polyethylene terephthalate film is used as a base material, the elastic modulus of the base material tends to decrease as the content of the ethylene component in the copolymer components increases. Furthermore, when the amount of plasticizer added to the resin composition constituting the base material increases, the elastic modulus of the base material tends to decrease.
  • the adhesive layer is not particularly limited as long as it has appropriate pressure-sensitive adhesive properties at room temperature, but it is preferably one having a shear storage modulus of 0.05 MPa to 0.50 MPa at 23°C.
  • the surface of a semiconductor wafer is usually uneven because circuits and the like are formed thereon.
  • the shear storage modulus of the adhesive layer is more preferably 0.12 to 0.35 MPa.
  • the shear storage modulus of the adhesive layer means the shear storage modulus before curing by energy ray irradiation when the adhesive layer is formed from an energy ray curable adhesive.
  • the shear storage modulus can be measured by the following method.
  • a measurement sample was prepared by punching out a circular shape with a diameter of 7.9 mm from an adhesive layer with a thickness of about 0.5 to 1 mm.
  • ARES dynamic viscoelasticity measuring device manufactured by Rheometric, measure the elastic modulus of the measurement sample when changing the temperature at a frequency of 1 Hz and a temperature range of -30°C to 150°C at a heating rate of 3°C/min. .
  • the elastic modulus at the measurement temperature of 23°C is defined as the shear storage modulus at 23°C.
  • the thickness of the adhesive layer is preferably less than 100 ⁇ m, more preferably 5 to 80 ⁇ m, and even more preferably 10 to 70 ⁇ m.
  • the adhesive layer is formed from, for example, an acrylic adhesive, a urethane adhesive, a rubber adhesive, a silicone adhesive, etc., and an acrylic adhesive is preferred. Moreover, it is preferable that the adhesive layer is formed from an energy ray-curable adhesive.
  • the adhesive layer is formed from an energy ray curable adhesive, so that the shear storage modulus at 23°C is set within the above range before curing by energy ray irradiation, and the peeling force is set to 1000 mN after curing. /50mm or less.
  • the adhesive layer in the present invention should not be interpreted as being limited to these.
  • the energy ray curable adhesive include, in addition to a non-energy ray curable adhesive resin (also referred to as "adhesive resin I"), an energy ray curable adhesive containing an energy ray curable compound other than the adhesive resin. (hereinafter also referred to as "X-type adhesive composition”) can be used.
  • an energy ray curable adhesive an energy ray curable adhesive resin (hereinafter also referred to as "Adhesive Resin II”), which has an unsaturated group introduced into the side chain of a non-energy ray curable adhesive resin, is used.
  • a pressure-sensitive adhesive composition (hereinafter also referred to as "Y-type pressure-sensitive adhesive composition”) which contains the energy ray-curable compound as a main component and does not contain any energy ray-curable compounds other than the adhesive resin may also be used.
  • the energy ray curable adhesive may be a combination of X type and Y type, that is, an energy ray curable adhesive containing an energy ray curable compound other than the adhesive resin in addition to the energy ray curable adhesive resin II.
  • a pressure-sensitive adhesive composition (hereinafter also referred to as "XY-type pressure-sensitive adhesive composition") may be used.
  • XY-type pressure-sensitive adhesive composition it is preferable to use an XY type adhesive composition.
  • the adhesive may be formed from a non-energy ray-curable adhesive composition that does not harden even when irradiated with energy rays.
  • the non-energy ray curable adhesive composition contains at least the non-energy ray curable adhesive resin I, but does not contain the energy ray curable adhesive resin II and the energy ray curable compound described above. be.
  • adhesive resin is used to refer to one or both of the above-described adhesive resin I and adhesive resin II.
  • Specific adhesive resins include, for example, acrylic resins, urethane resins, rubber resins, silicone resins, and acrylic resins are preferred.
  • acrylic adhesive in which an acrylic resin is used as the adhesive resin will be described in more detail.
  • An acrylic polymer (b) is used as the acrylic resin.
  • the acrylic polymer (b) is obtained by polymerizing a monomer containing at least an alkyl (meth)acrylate, and contains structural units derived from the alkyl (meth)acrylate.
  • Examples of the alkyl (meth)acrylate include those in which the alkyl group has 1 to 20 carbon atoms, and the alkyl group may be linear or branched.
  • alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. ) acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, and the like. Alkyl (meth)acrylates may be used alone or in combination of two or more.
  • the acrylic polymer (b) preferably contains a structural unit derived from an alkyl (meth)acrylate in which the alkyl group has 4 or more carbon atoms.
  • the alkyl (meth)acrylate preferably has 4 to 12 carbon atoms, more preferably 4 to 6 carbon atoms.
  • the alkyl (meth)acrylate in which the alkyl group has 4 or more carbon atoms is preferably an alkyl acrylate.
  • the alkyl (meth)acrylate whose alkyl group has 4 or more carbon atoms is based on the total amount of monomers (hereinafter also simply referred to as "total monomer amount") constituting the acrylic polymer (b).
  • the content is preferably 40% to 98% by weight, more preferably 45% to 95% by weight, and still more preferably 50% to 90% by weight.
  • the acrylic polymer (b) contains alkyl groups in order to adjust the elastic modulus and adhesive properties of the adhesive layer.
  • a copolymer containing a structural unit derived from an alkyl (meth)acrylate having 1 to 3 carbon atoms is preferable.
  • the alkyl (meth)acrylate is preferably an alkyl (meth)acrylate having 1 or 2 carbon atoms, more preferably methyl (meth)acrylate, and even more preferably methyl methacrylate.
  • the alkyl (meth)acrylate whose alkyl group has 1 to 3 carbon atoms is preferably 1% by mass to 30% by mass, more preferably 3% by mass to 3% by mass, based on the total amount of monomers.
  • the amount is 26% by weight, more preferably 6% to 22% by weight.
  • the acrylic polymer (b) has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the alkyl (meth)acrylate described above.
  • the functional group of the functional group-containing monomer include a hydroxyl group, a carboxy group, an amino group, and an epoxy group.
  • the functional group-containing monomer reacts with a crosslinking agent described below to become a crosslinking starting point, or reacts with an unsaturated group-containing compound to introduce an unsaturated group into the side chain of the acrylic polymer (b). is possible.
  • Examples of functional group-containing monomers include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, and the like. These monomers may be used alone or in combination of two or more. Among these, hydroxyl group-containing monomers and carboxyl group-containing monomers are preferred, and hydroxyl group-containing monomers are more preferred.
  • hydroxyl group-containing monomers examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-hydroxybutyl (meth)acrylate.
  • 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 functional group-containing monomer is preferably 1% by mass to 35% by mass, more preferably 3% to 32% by mass, still more preferably 6% by mass to the total amount of monomers constituting the acrylic polymer (b). It is 30% by mass.
  • the acrylic polymer (b) may also be derived from monomers copolymerizable with the above acrylic monomers, such as styrene, ⁇ -methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide. It may also include structural units.
  • the above acrylic polymer (b) can be used as a non-energy ray-curable adhesive resin I (acrylic resin).
  • an energy ray-curable acrylic resin one in which a compound having a photopolymerizable unsaturated group (also referred to as an unsaturated group-containing compound) is reacted with the functional group of the acrylic polymer (b) is used. Can be mentioned.
  • the unsaturated group-containing compound is a compound that has both a substituent that can bond to the functional group of the acrylic polymer (b) and a photopolymerizable unsaturated group.
  • the photopolymerizable unsaturated group include a (meth)acryloyl group, a vinyl group, an allyl group, a vinylbenzyl group, and a (meth)acryloyl group is preferred.
  • examples of the substituent which the unsaturated group-containing compound has and which can bond to a functional group include an isocyanate group and a glycidyl group. Therefore, examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, glycidyl (meth)acrylate, and the like.
  • the unsaturated group-containing compound reacts with a part of the functional groups of the acrylic polymer (b), and specifically, 50 to 98 moles of the functional groups of the acrylic polymer (b). % of the unsaturated group-containing compound, more preferably 55 to 93 mol %.
  • the weight average molecular weight (Mw) of the acrylic resin is preferably 300,000 to 1,600,000, more preferably 400,000 to 1,400,000, and even more preferably 500,000 to 1,200,000.
  • the energy ray-curable compound contained in the X-type or XY-type pressure-sensitive adhesive composition is preferably a monomer or oligomer that has an unsaturated group in its molecule and can be polymerized and cured by energy ray irradiation.
  • Examples of such energy ray-curable compounds include trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4- Polyvalent (meth)acrylate monomers such as butylene glycol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy ( Examples include oligomers such as meth)acrylate.
  • urethane (meth)acrylate oligomers are preferred because they have a relatively high molecular weight and are difficult to reduce the shear storage modulus of the adhesive layer.
  • the molecular weight (weight average molecular weight in the case of oligomers) of the energy ray curable compound is preferably 100 to 12,000, more preferably 200 to 10,000, still more preferably 400 to 8,000, and even more preferably 600 to 10,000. 6,000.
  • the content of the energy ray-curable compound in the X-type adhesive composition is preferably 40 parts by mass to 200 parts by mass, more preferably 50 parts by mass to 150 parts by mass, and more preferably 50 parts by mass to 150 parts by mass, based on 100 parts by mass of adhesive resin. Preferably it is 60 parts by mass to 90 parts by mass.
  • the content of the energy ray-curable compound in the XY-type adhesive composition is preferably 1 part by mass to 30 parts by mass, more preferably 2 parts by mass to 20 parts by mass, based on 100 parts by mass of the adhesive resin. parts, more preferably 3 parts to 15 parts by weight.
  • the adhesive resin is energy ray curable, so even if the content of the energy ray curable compound is small, it is possible to sufficiently reduce the peeling force after energy ray irradiation. It is.
  • the adhesive composition further contains a crosslinking agent.
  • the crosslinking agent crosslinks the adhesive resins by reacting with, for example, a functional group derived from a functional group-containing monomer that the adhesive resin has.
  • the crosslinking agent include isocyanate crosslinking agents such as tolylene diisocyanate, hexamethylene diisocyanate, and adducts thereof; epoxy crosslinking agents such as ethylene glycol glycidyl ether; hexa[1-(2-methyl)-aziridinyl ] Aziridine crosslinking agents such as triphosphatriazine; Chelate crosslinking agents such as aluminum chelate; and the like. These crosslinking agents may be used alone or in combination of two or more.
  • the amount of the crosslinking agent is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.03 parts by mass to 7 parts by mass, based on 100 parts by mass of the adhesive resin. More preferably, the amount is 0.05 parts by mass to 4 parts by mass.
  • the adhesive composition when the adhesive composition is energy ray curable, it is preferable that the adhesive composition further contains a photopolymerization initiator.
  • a photopolymerization initiator By containing a photopolymerization initiator, the curing reaction of the pressure-sensitive adhesive composition can sufficiently proceed even with relatively low-energy energy rays such as ultraviolet rays.
  • photopolymerization initiators examples include benzoin compounds, acetophenone compounds, acylphosphinoxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and photosensitizers such as amines and quinones, and more.
  • 1-hydroxycyclohexylphenyl ketone 2-hydroxy-2-methyl-1-phenyl-propan-1-one
  • benzoin benzoin methyl ether
  • benzoin ethyl ether benzoin isopropyl ether
  • benzylphenyl examples include sulfide, tetramethylthiuram monosulfide, azobisisobutyrolonitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and the like.
  • photopolymerization initiators may be used alone or in combination of two or more.
  • the amount of the photopolymerization initiator is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.03 parts to 5 parts by mass, and even more preferably 0.05 parts by mass, based on 100 parts by mass of the adhesive resin. Parts by mass to 5 parts by mass.
  • the adhesive composition may contain other additives to the extent that the effects of the present invention are not impaired.
  • additives include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust preventives, pigments, and dyes.
  • the blending amount of the additives is preferably 0.01 parts by mass to 6 parts by mass based on 100 parts by mass of the adhesive resin.
  • the adhesive composition may be further diluted with an organic solvent to form a solution of the adhesive composition from the viewpoint of improving the applicability to a substrate, a buffer layer, or a release sheet.
  • organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, and isopropanol.
  • the organic solvents used during the synthesis of the adhesive resin may be used as they are, or organic solvents other than those used during the synthesis may be used in order to uniformly apply the solution of the adhesive composition.
  • One or more organic solvents may be added.
  • a release sheet may be attached to the surface of the adhesive tape. Specifically, the release sheet is attached to the surface of the adhesive layer of the adhesive tape. The release sheet protects the adhesive layer during transportation and storage by being attached to the surface of the adhesive layer. The release sheet is releasably attached to the adhesive tape, and is peeled off and removed from the adhesive tape before the adhesive tape is used (ie, before the wafer is attached).
  • a release sheet whose at least one side has been subjected to a release treatment is used, and specifically, a release sheet having a release agent coated on the surface of a base material for the release sheet can be mentioned.
  • a resin film is preferable, and examples of the resin constituting the resin film include polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin, polypropylene resin, polyethylene resin, etc. Polyolefin resins and the like can be mentioned.
  • the release agent include rubber elastomers such as silicone resins, olefin resins, isoprene resins, and butadiene resins, long-chain alkyl resins, alkyd resins, and fluororesins.
  • the thickness of the release sheet is not particularly limited, but is preferably 10 ⁇ m to 200 ⁇ m, more preferably 20 ⁇ m to 150 ⁇ m.
  • the method of manufacturing the adhesive tape for semiconductor processing of the present invention is not particularly limited, and can be manufactured by any known method.
  • a method for manufacturing an adhesive tape having a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order is as follows.
  • the buffer layer When the buffer layer is formed from a buffer layer forming composition containing an energy beam polymerizable compound, the buffer layer formed by coating and curing the buffer layer forming composition on a release sheet, and the base material. By laminating them together and removing the release sheet, a laminate of the buffer layer and the base material can be obtained.
  • the adhesive layer provided on the release sheet is bonded to the base material side of the laminate to produce an adhesive tape with the release sheet attached to the surface of the adhesive layer.
  • the release sheet attached to the surface of the adhesive layer may be peeled off and removed as appropriate before use of the adhesive tape.
  • a method for forming a buffer layer on a release sheet is to directly apply a composition for forming a buffer layer onto a release sheet using a known coating method to form a coating film, and then irradiate this coating film with energy rays. By doing so, a buffer layer can be formed.
  • the buffer layer may be formed by directly coating the composition for forming a buffer layer on one side of the base material and drying it by heating or by irradiating the coated film with energy rays.
  • Examples of methods for applying the composition for forming a buffer layer include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating. Further, in order to improve the coating properties, an organic solvent may be added to the composition for forming a buffer layer, and the composition may be applied in the form of a solution onto a release sheet.
  • the buffer layer forming composition contains an energy ray polymerizable compound
  • the curing of the buffer layer may be performed in one curing process, or may be performed in multiple steps.
  • the coating film on the release sheet may be completely cured to form a buffer layer and then bonded to the base material, or the buffer layer forming film in a semi-cured state may be formed without completely curing the coating film.
  • the buffer layer may be formed by irradiating energy rays again to completely cure the film.
  • the coating film of the composition for forming a buffer layer may be exposed, but it is possible to cover the coating film with a release sheet or base material and irradiate it with energy rays without exposing the coating film. Preferably, it is cured.
  • the method for forming the adhesive layer on the release sheet is to directly apply the adhesive (adhesive composition) onto the release sheet using a known coating method and heat and dry the coated film. layers can be formed.
  • an adhesive layer may be formed by directly applying an adhesive (adhesive composition) to one side of the base material.
  • adhesive adhesive composition
  • methods for applying the adhesive include spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating as shown in the buffer layer manufacturing method.
  • the adhesive tape for semiconductor processing of the present invention is used by applying it to the front surface (circuit forming surface) of a semiconductor wafer and cutting it along the outer periphery of the semiconductor wafer when grinding the back surface of the semiconductor wafer.
  • the adhesive tape for semiconductor processing of the present invention is used when back-grinding a semiconductor wafer (specifically, during semiconductor chip manufacturing including a back-grinding process of the semiconductor wafer). It is used by attaching it to the circuit forming surface) and cutting it along the outer periphery of the semiconductor wafer.
  • Examples of a semiconductor chip manufacturing method that includes a step of back grinding a semiconductor wafer include a method in which a semiconductor wafer is back ground and then diced into pieces, and the above-mentioned DBG or a modification of DBG.
  • the adhesive tape for semiconductor processing of the present invention has excellent cuttability with a blade. Therefore, when cutting the adhesive tape for semiconductor processing along the outer periphery of a semiconductor wafer, cut dust is less likely to be generated, and during semiconductor chip manufacturing including the back grinding process of the semiconductor wafer, the cut dust caused by the semiconductor wafer is less likely to be generated. The occurrence of chipping and damage to the chip is suppressed.
  • the method of use (1) or (2) below is provided.
  • a method of using the adhesive tape for semiconductor processing of the present invention which comprises: attaching the adhesive tape for semiconductor processing to the surface of the semiconductor wafer when back-grinding the semiconductor wafer; A usage method for cutting along the outer circumference of a semiconductor wafer.
  • the method uses, as the semiconductor wafer, a semiconductor wafer with grooves formed on the surface side or a semiconductor wafer with a modified region formed inside.
  • the method of manufacturing a semiconductor device of the present invention is a method of manufacturing a semiconductor chip including a step of grinding the back side of a semiconductor wafer, in which the adhesive tape for semiconductor processing of the present invention is affixed to the front surface (circuit formation surface) of the semiconductor wafer, and the semiconductor
  • the method includes a step (S1) of cutting the processing adhesive tape along the outer periphery of the semiconductor wafer.
  • the adhesive tape for semiconductor processing of the present invention has excellent cuttability with a blade. Therefore, in the step (S1), cut dust is hardly generated, and the occurrence of cracks in the semiconductor chip due to the cut dust is suppressed.
  • FIG. 2 shows a process schematic diagram of the method for manufacturing a semiconductor device of the present invention.
  • the method for manufacturing a semiconductor device of the present invention includes applying an adhesive tape for semiconductor processing to the surface (circuit forming surface) of a semiconductor wafer, and cutting the adhesive tape for semiconductor processing along the outer periphery of the semiconductor wafer.
  • the method includes a step (S1) and a step (S2) of grinding the semiconductor wafer from the back side. After the step (S2), the semiconductor wafer may be diced into individual pieces (aspect 1). Further, the semiconductor wafer may be separated into pieces in the step (S2) (aspect 2).
  • the semiconductor wafer may be a semiconductor wafer with grooves formed on its surface side, and in the step (S2), the semiconductor wafer may be singulated into a plurality of chips using the grooves as starting points.
  • the semiconductor wafer a semiconductor wafer in which a modified region is formed is used, or a modified region is formed inside the semiconductor wafer after the step (S1), and in the step (S2), The semiconductor wafer may be singulated into a plurality of chips starting from the modified region.
  • step (S1) the adhesive tape for semiconductor processing of the present invention is applied to the surface (circuit formation surface) of the semiconductor wafer, and the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer.
  • the adhesive tape for semiconductor processing is applied so as to cover the surface (circuit forming surface) of the semiconductor wafer and the outer peripheral table extending around the outer periphery of the semiconductor wafer.
  • the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer by inserting the blade of a cutter or the like from the surface on the buffer layer side.
  • the cutting speed is usually 10 to 300 mm/s.
  • the temperature of the blade during cutting may be at room temperature, or the blade may be heated for cutting.
  • Examples of semiconductor wafers used in this manufacturing method include silicon wafers, gallium arsenide wafers, silicon carbide wafers, lithium tantalate wafers, lithium niobate wafers, gallium nitride wafers, indium phosphorous wafers, and glass wafers.
  • the thickness of the semiconductor wafer before back grinding is not particularly limited, but is usually about 500 ⁇ m to 1000 ⁇ m.
  • circuit formation on the surface of a semiconductor wafer can be performed by various methods including conventionally widely used methods such as etching method and lift-off method.
  • the semiconductor wafer to which the adhesive tape for semiconductor processing is attached in step (S1) is a semiconductor wafer with grooves formed on its surface.
  • a semiconductor wafer having grooves formed on its surface can be manufactured by laser dicing, blade dicing, or the like using a conventionally known wafer dicing device or the like. The grooves serve as starting points for dividing the semiconductor wafer into individual semiconductor chips.
  • the semiconductor wafer to which the adhesive tape for semiconductor processing is attached in step (S1) is a semiconductor wafer in which a modified region is formed.
  • the modified region may be formed after step (S1).
  • the modified region is a portion of the semiconductor wafer that has been made brittle, and serves as a starting point for dividing the semiconductor wafer into individual chips.
  • a semiconductor wafer with a modified region formed therein is produced by laser irradiation or plasma irradiation focused on the inside of the semiconductor wafer. Laser or plasma irradiation may be performed from the front side or the back side of the semiconductor wafer.
  • the semiconductor wafer with the adhesive tape for semiconductor processing on which the step (S1) has been completed is placed on the chuck table, and is held by suction on the chuck table. At this time, the semiconductor wafer with the adhesive tape for semiconductor processing attached thereto is placed on the chuck table so that the chuck table and the buffer layer of the adhesive tape for semiconductor processing are in direct contact with each other. In other words, the front side of the semiconductor wafer is placed on the chuck table side.
  • step (S3) is performed to separate the semiconductor wafer into pieces.
  • a semiconductor wafer that does not have such a division starting point is used instead of a semiconductor wafer that has a dividing starting point such as a semiconductor wafer with grooves formed on the surface or a semiconductor wafer with a modified region formed inside.
  • step (S2)) the back surface of the semiconductor wafer on the chuck table is ground.
  • the thickness of the semiconductor wafer after back grinding is not particularly limited, but is preferably about 5 ⁇ m to 100 ⁇ m, more preferably 10 ⁇ m to 45 ⁇ m.
  • step (S3) the semiconductor wafer subjected to step (S2) is diced into individual pieces. Dicing can be appropriately performed by employing conventionally known methods such as blade dicing and laser dicing.
  • the shape of the diced semiconductor chip may be square, or may be an elongated shape such as a rectangle.
  • the thickness of the diced semiconductor chip is not particularly limited, but is preferably about 5 ⁇ m to 100 ⁇ m, more preferably 10 ⁇ m to 45 ⁇ m.
  • the area of the diced semiconductor chip is not particularly limited, but is preferably less than 600 mm 2 , more preferably less than 400 mm 2 , and still more preferably less than 300 mm 2 .
  • step (S2) the back surface of the semiconductor wafer is ground and the semiconductor wafer is cut into pieces.
  • step (S2) the back surface of the semiconductor wafer on the chuck table is ground to separate the semiconductor wafer into a plurality of semiconductor chips.
  • a semiconductor wafer with grooves formed on its surface is used.
  • the back surface of the semiconductor wafer is ground to at least the bottom of the groove.
  • the grooves become cuts that penetrate the semiconductor wafer, and the semiconductor wafer is divided by the cuts to be singulated into individual semiconductor chips.
  • a semiconductor wafer in which a modified region is formed is used.
  • a modified region may be formed inside the semiconductor wafer after the step (S1).
  • back grinding may be performed until reaching the modified region, but it is not necessary to strictly reach the modified region. That is, back grinding may be performed to a position close to the modified region so that the semiconductor wafer is broken starting from the modified region and separated into semiconductor chips.
  • a pickup tape which will be described later, may be attached to the obtained plurality of semiconductor chips, and then the pickup tape may be stretched to widen the gaps between the chips.
  • dry polishing may be performed.
  • the shape, thickness, and area of the diced semiconductor chips are as described in the first embodiment. Note that when using a semiconductor wafer in which a modified region is formed, it is easy to make the thickness of the diced semiconductor chips 50 ⁇ m or less, more preferably 10 ⁇ m to 45 ⁇ m.
  • the adhesive tape for semiconductor processing of the present invention has excellent cuttability with a blade. Therefore, cut dust is less likely to be generated in the step (S1). Therefore, in the step (S2) of Aspect 1 and the step (S2) of Aspect 2, even when manufacturing thinner and smaller semiconductor chips, chipping and damage of semiconductor chips caused by the cut dust may occur. Occurrence is suppressed.
  • the adhesive tape for semiconductor processing is peeled off from the diced semiconductor wafer (ie, a plurality of semiconductor chips).
  • This step is performed, for example, by the following method.
  • the adhesive layer of the adhesive tape for semiconductor processing is formed from an energy ray-curable adhesive
  • the adhesive layer is cured by irradiating with energy rays.
  • a pick-up tape is attached to the back side of the diced semiconductor wafer, and the position and orientation are adjusted so that it can be picked up.
  • the ring frame placed on the outer peripheral side of the wafer is also attached to the pick-up tape, and the outer peripheral edge of the pick-up tape is fixed to the ring frame.
  • the wafer and ring frame may be attached to the pickup tape at the same time or at different times.
  • the adhesive tape is peeled off from the plurality of semiconductor chips held on the pickup tape.
  • the pickup tape is not particularly limited, but is configured, for example, by an adhesive tape including a base material and an adhesive layer provided on at least one surface of the base material.
  • Adhesive tape can be a laminate of a film adhesive and a release sheet, a laminate of a dicing tape and a film adhesive, or an adhesive layer and release sheet that have the functions of both a dicing tape and a die bonding tape. Examples include dicing and die bonding tapes.
  • a film adhesive may be applied to the back side of the semiconductor wafer that has been separated into pieces. When using a film adhesive, the film adhesive may have the same shape as the wafer.
  • the adhesive tape for semiconductor processing according to the present invention provides a group of thinner semiconductor chips with a smaller kerf width when a semiconductor wafer is diced. It can be particularly preferably used in a DBG modification method.
  • the adhesive tape for semiconductor processing of the present invention can of course be used to temporarily hold a workpiece during processing of glass, ceramics, etc. It can also be used as various removable adhesive tapes.
  • a high-pressure mercury lamp was applied to the buffer layer composition layer under the conditions of an illuminance of 160 mW/cm 2 and an irradiation amount of 500 mJ/cm 2 .
  • the composition layer for the buffer layer is cured by UV irradiation to form a buffer layer A-1 with a thickness of 28 ⁇ m on one side of the PET film that is the base material, and the PET base material with the buffer layer A-1 is cured. was created.
  • ⁇ Manufacture example A2 Formation of buffer layer A-2> A buffer layer A-2 having a thickness of 28 ⁇ m was formed on a PET film as a base material in the same manner as in Production Example A1 by changing the formulation of the buffer layer composition as follows.
  • ⁇ Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ⁇ 4-tert-butylcyclohexanol acrylate: 40 parts by mass ⁇ Dipentaerythritol hexaacrylate: 10 parts by mass
  • Photopolymerization initiator manufactured by BASF "Irgacure” 1173''): 2.0 parts by mass
  • ⁇ Manufacture example A3 Formation of buffer layer A-3> A buffer layer A-3 having a thickness of 28 ⁇ m was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
  • ⁇ Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ⁇ 4-tert-butylcyclohexanol acrylate: 45 parts by mass ⁇ Dipentaerythritol hexaacrylate: 5 parts by mass
  • Photopolymerization initiator manufactured by BASF "Irgacure” 1173''): 2.0 parts by mass
  • ⁇ Production Example A4 Formation of buffer layer A-4> A buffer layer A-4 having a thickness of 28 ⁇ m was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
  • ⁇ Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ⁇ Isobornyl acrylate: 45 parts by mass ⁇ Dipentaerythritol hexaacrylate: 5 parts by mass ⁇ Photopolymerization initiator (“Irgacure 1173” manufactured by BASF): 2.0 parts by mass
  • ⁇ Comparative manufacturing example B1 Formation of manufacturing of buffer layer B-1> A buffer layer B-1 having a thickness of 28 ⁇ m was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
  • ⁇ Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ⁇ 3,3,5-trimethylcyclohexanol acrylate: 50 parts by mass
  • Photopolymerization initiator (“Irgacure 1173” manufactured by BASF): 2.0 parts by mass Department
  • ⁇ Comparative production example B2 Formation of buffer layer B-2> A buffer layer B-2 having a thickness of 28 ⁇ m was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
  • ⁇ Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ⁇ Isobornyl acrylate: 45 parts by mass ⁇ Tricyclodecane dimethanol diacrylate: 5 parts by mass ⁇ Photopolymerization initiator ("Irgacure 1173" manufactured by BASF Corporation) ): 2.0 parts by mass
  • ⁇ Comparative manufacturing example B3 Formation of buffer layer B-3> A buffer layer B-3 having a thickness of 28 ⁇ m was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
  • ⁇ Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass
  • ⁇ Cyclic trimethylolpropane formal acrylate 50 parts by mass
  • Photopolymerization initiator (“Irgacure 1173” manufactured by BASF): 2.0 parts by mass
  • ⁇ Reference example C1 Base material C-1> As the substrate C-1, a PET film ("Cosmoshine A4300" manufactured by Toyobo Co., Ltd., PET film with easy adhesive layer on both sides, thickness: 50 ⁇ m) was prepared.
  • a PET film (“Cosmoshine A4300” manufactured by Toyobo Co., Ltd., PET film with easy adhesive layer on both sides, thickness: 50 ⁇ m) was prepared.
  • Base material C-2> A polyolefin (PO) film (low-density polyolefin film, thickness: 25 ⁇ m) was prepared as the substrate C-2.
  • PO polyolefin
  • the angle between the surface of the buffer layer and the cutting edge of the blade was set to 57.2°, and the blade was moved in a straight line along the semiconductor wafer at a cutting speed of 80 mm/s.
  • the state of the cross section was analyzed.
  • the blade property was assumed to be a rigid body.
  • the buffer layer and base material were analyzed in the following combinations. ⁇ Example 1 sim. :Buffer layer A-1/PET ⁇ Example 2 sim.
  • the evaluation criteria were as follows, and a rating of 3 or higher was considered a pass. 1: The cross section of the sheet is extremely rough. 2: The cross section of the sheet is rough. 3: The cross section of the sheet is slightly rough. 4: Slight roughness is observed in the cross section of the sheet. 5: No roughness is observed in the cross section of the sheet.
  • an adhesive layer was attached to the PET base material side surface of the PET base material with buffer layer B-3 formed in Comparative Production Example B3, and the lamination of buffer layer B-3/PET base material/adhesive layer was performed.
  • An adhesive tape for semiconductor processing with a structure was produced.
  • Example 1exp. and Comparative Example 3exp An adhesive tape for semiconductor processing was attached to a silicon wafer having a diameter of 12 inches and a thickness of 775 ⁇ m using a backgrinding tape laminator (manufactured by Lintec Corporation, device name: “RAD-3510F/12”). Then, the adhesive tape for semiconductor processing was cut along the outer periphery of the silicon wafer with an art knife (manufactured by OLFA, model number "XB10"). The art knife was inserted from the buffer layer side of the adhesive tape for semiconductor processing. The angle formed between the surface of the buffer layer and the cutting edge of the blade was 57.2°. Moreover, the cutting speed was 80 mm/s. The cross section of the cut adhesive tape for semiconductor processing was observed using a scanning electron microscope (SEM), and evaluated using the same criteria as the evaluation of the sheet cross section (1).
  • SEM scanning electron microscope
  • Comparative Example 1sim. Comparative Example 2sim. It can be seen that the buffer layer does not satisfy the requirement ( ⁇ ) in both cases, and the cutting performance with the blade is poor in both cases.
  • Comparative Example 3sim It can be seen that the buffer layer does not satisfy either requirement ( ⁇ ) or requirement ( ⁇ ), and has extremely poor cutting performance with a blade.
  • Reference example 1sim where the base material satisfies the requirement ( ⁇ ).
  • Reference Example 2sim It can be seen that the cutting performance by the blade is good in all cases.
  • Reference Example 2sim In this case, since the cutting performance of the blade is good even though requirement ( ⁇ ) is not met, it is not possible to judge whether the cutting performance of the base material is good or bad based on requirement ( ⁇ ) and requirement ( ⁇ ). Recognize.
  • Example 1exp. shown in Table 3. and Comparative Example 3exp. is Example 1 sim. and Comparative Example 3sim. These are the results of experimental confirmation.
  • Example 1exp. and Comparative Example 3exp. The evaluation results of the cutting performance by the blade examined in Example 1 sim. and Comparative Example 3sim. It can be seen that the results are in complete agreement with the evaluation results of the cutting performance of the blade investigated by This is also clear from the results shown in FIGS. 4 and 5.

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Abstract

The present invention addresses the problem of providing an adhesive tape for semiconductor processing that has excellent cutability by blade. According to the present invention, an adhesive tape for semiconductor processing includes a layered structure that is formed by layering, in order, a buffer layer, a substrate, and an adhesive layer, the buffer layer satisfying both condition (α) and condition (β). - Condition (α): the breaking energy of the buffer layer at 23°C is at least 15 MJ/m3. - Condition (β): When the buffer layer is tension tested at 23°C, the slope Δρ80–100 of the increase in stress as the strain (ε80) at 80% of the breaking strain (ε100) increases to the breaking strain (ε100) is at least 30 MPa.

Description

半導体加工用粘着テープAdhesive tape for semiconductor processing
　本発明は、半導体加工用粘着テープに関する。さらに詳述すると、本発明は、半導体加工用粘着テープ、当該半導体加工用粘着テープの使用方法、及び当該半導体加工用粘着テープを利用した半導体装置の製造方法に関する。 The present invention relates to an adhesive tape for semiconductor processing. More specifically, the present invention relates to an adhesive tape for semiconductor processing, a method of using the adhesive tape for semiconductor processing, and a method of manufacturing a semiconductor device using the adhesive tape for semiconductor processing.
　近年、各種電子機器の小型化及び多機能化の急速な進展に伴い、各種電子機器に搭載される半導体チップの小型化及び薄型化が求められている。
　半導体チップの薄型化は、一般に、半導体ウエハの裏面を研削することにより行われる。また、薄型化された半導体チップを得るための手法として、先ダイシング法（ＤＢＧ：Ｄｉｃｉｎｇ　Ｂｅｆｏｒｅ　Ｇｒｉｎｄｉｎｇ）と呼ばれる手法が知られている。ＤＢＧは、半導体ウエハの表面側（回路形成面側）から所定深さの溝をダイシングブレード等により形成した後、半導体ウエハ裏面側から研削を行い、研削により半導体ウエハを個片化して半導体チップを得る手法である。
　ＤＢＧでは、半導体ウエハの裏面研削と、半導体ウエハの個片化を同時に行うことができるので、薄型化された半導体チップを効率よく製造することができる。 2. Description of the Related Art In recent years, with the rapid progress in miniaturization and multifunctionalization of various electronic devices, there has been a demand for smaller and thinner semiconductor chips mounted on various electronic devices.
Semiconductor chips are generally made thinner by grinding the back surface of a semiconductor wafer. Further, as a method for obtaining a thinned semiconductor chip, a method called dicing before grinding (DBG) is known. In DBG, grooves of a predetermined depth are formed from the front side (circuit forming side) of a semiconductor wafer using a dicing blade, etc., and then the semiconductor wafer is ground from the back side, and the semiconductor wafer is cut into individual pieces by grinding to form semiconductor chips. This is a method of obtaining
In DBG, it is possible to grind the back surface of a semiconductor wafer and to cut the semiconductor wafer into individual pieces at the same time, so that thinned semiconductor chips can be efficiently manufactured.
　また、ＤＢＧの変形法として、半導体ウエハの表面側に溝を形成することなく、半導体ウエハの内部にレーザー又はプラズマ等により改質領域を形成し、半導体ウエハの裏面研削時の応力等で半導体ウエハを個片化して半導体チップを得る手法も提案されている。この手法の場合、半導体ウエハが改質領域を起点として結晶方向に切断される。そのため、ダイシングブレードを用いたＤＢＧよりもチッピングの発生を低減できる。その結果、抗折強度に優れた半導体チップを得ることができ、半導体チップのさらなる薄型化が可能となる。また、ダイシングブレード等により半導体ウエハ表面に所定深さの溝を形成するＤＢＧと比較して、ダイシングブレードにより半導体ウエハを削り取る領域がないため（換言すれば、カーフ幅が極小であるため）、半導体チップの収率に優れるという利点もある。 In addition, as a modified method of DBG, a modified region is formed inside the semiconductor wafer using a laser or plasma, etc., without forming a groove on the front surface side of the semiconductor wafer, and the semiconductor wafer is A method of obtaining semiconductor chips by dividing into individual pieces has also been proposed. In this method, a semiconductor wafer is cut in the crystal direction starting from the modified region. Therefore, occurrence of chipping can be reduced more than in DBG using a dicing blade. As a result, a semiconductor chip with excellent bending strength can be obtained, and the semiconductor chip can be made even thinner. Also, compared to DBG, which forms grooves of a predetermined depth on the surface of the semiconductor wafer using a dicing blade, etc., there is no area to scrape off the semiconductor wafer with the dicing blade (in other words, the kerf width is extremely small), so the semiconductor Another advantage is that the yield of chips is excellent.
　ところで、ＤＢＧ又はＤＢＧの変形法等の半導体ウエハの裏面研削工程を含む半導体チップの製造時には、半導体ウエハ表面の回路を保護し、また、半導体ウエハ及び半導体チップを保持するために、半導体ウエハ表面にバックグラインドシートと呼ばれる半導体加工用粘着テープを貼付するのが一般的である。
　このような半導体加工用粘着テープとしては、例えば、緩衝層と、基材と、粘着剤層とがこの順で積層された積層構造を有する半導体加工用粘着テープが提案されている（例えば、特許文献１等を参照）。 By the way, when manufacturing a semiconductor chip that includes a back grinding process of a semiconductor wafer using DBG or a modification method of DBG, the surface of the semiconductor wafer is It is common to attach an adhesive tape for semiconductor processing called a backgrind sheet.
As such an adhesive tape for semiconductor processing, an adhesive tape for semiconductor processing has been proposed, for example, which has a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order (for example, a patent (See Reference 1, etc.).
特開２０１５－１８３００８号公報Japanese Patent Application Publication No. 2015-183008
　ところで、ＤＢＧ又はＤＢＧの変形法等の半導体ウエハの裏面研削工程を含む半導体チップの製造時において、半導体ウエハをグラインダ等により裏面研削する際に、半導体ウエハの外周に余分な半導体加工用粘着テープがあると、グラインダが余分な半導体加工用粘着テープを咬み込むことがある。そこで、半導体加工用粘着テープは、裏面研削の前に半導体ウエハの外周に沿って切断される。 By the way, during the manufacturing of semiconductor chips that includes a back grinding process of a semiconductor wafer using DBG or a modification method of DBG, when back grinding the semiconductor wafer with a grinder or the like, excess adhesive tape for semiconductor processing may be left on the outer periphery of the semiconductor wafer. If so, the grinder may bite into the excess adhesive tape for semiconductor processing. Therefore, the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer before back grinding.
　しかしながら、半導体チップの小型化及び薄型化に伴い、半導体加工用粘着テープの切断時に生じるカットダストによって、半導体チップの欠けや破損（以下、これらを「半導体チップのクラック」と称する）が発生することがある。
　そこで、本発明者らは、半導体チップのクラックの発生を抑制すべく、カットダストが発生する主要因について検討した。その結果、半導体加工用粘着テープを刃で切断する際、刃と緩衝層との接触により緩衝層が擦られて、緩衝層を構成する樹脂が撚れ等を起こして切断面が荒れることで、カットダストが発生していることを突き止めた。 However, as semiconductor chips become smaller and thinner, chipping and breakage of semiconductor chips (hereinafter referred to as "semiconductor chip cracks") may occur due to cut dust generated when cutting adhesive tape for semiconductor processing. There is.
In order to suppress the occurrence of cracks in semiconductor chips, the inventors of the present invention investigated the main causes of cut dust generation. As a result, when cutting adhesive tape for semiconductor processing with a blade, the buffer layer is rubbed due to contact between the blade and the buffer layer, causing twisting of the resin that makes up the buffer layer and roughening of the cut surface. It was discovered that cut dust was generated.
　本発明者らは、かかる知見に基づき、カットダストの発生を抑制する手法として、半導体加工用粘着テープの刃による切断性を高めて、緩衝層の切断面の荒れを抑制することが有効であると考え、さらに鋭意検討を進め、本発明に至った。 Based on this knowledge, the present inventors have found that, as a method for suppressing the generation of cut dust, it is effective to improve the cutting performance of the adhesive tape for semiconductor processing by the blade and suppress roughness of the cut surface of the buffer layer. With this in mind, we conducted further intensive studies and arrived at the present invention.
　したがって、本発明の課題は、刃による切断性に優れる半導体加工用粘着テープを提供することを課題とする。 Therefore, an object of the present invention is to provide an adhesive tape for semiconductor processing that has excellent cuttability with a blade.
　本発明者らは、鋭意検討を重ねた結果、特定の要件を満たす緩衝層を有する半導体加工用粘着テープが、上記課題を解決し得ることを見出し、本発明を完成するに至った。 As a result of extensive studies, the present inventors have found that an adhesive tape for semiconductor processing having a buffer layer that satisfies specific requirements can solve the above problems, and have completed the present invention.
　すなわち、本発明は、下記［１］～［７］に関する。
　［１］　緩衝層と、基材と、粘着剤層とがこの順で積層された積層構造を有し、
　前記緩衝層が、下記要件（α）及び下記要件（β）の双方を満たす、半導体加工用粘着テープ。
・要件（α）：前記緩衝層の２３℃における破断エネルギーが１５ＭＪ／ｍ３以上である。
・要件（β）：温度２３℃において前記緩衝層を引張試験に供したときに、破断ひずみ（ε１００）の８０％のひずみ（ε８０）が前記破断ひずみ（ε１００）に増加するまでの、応力の増加勾配Δρ８０－１００が、３０ＭＰａ以上である。
　［２］　前記基材が、下記要件（γ）を満たす、上記［１］に記載の半導体加工用粘着テープ。
・要件（γ）：温度２３℃における破断ひずみ（ε１００）と温度２３℃における破断応力（ρ１００）との積が、６０ＭＰａ以上である。
　［３］　前記粘着剤層の厚さが、１００μｍ未満である上記［１］又は［２］に記載の半導体加工用粘着テープ。
　［４］　上記［１］～［３］のいずれかに記載の半導体加工用粘着テープの使用方法であって、
　半導体ウエハの裏面研削を行う際に、前記半導体加工用粘着テープを半導体ウエハの表面に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する、使用方法。
　［５］　上記［１］～［３］のいずれかに記載の半導体加工用粘着テープを半導体ウエハの表面に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する工程（Ｓ１）を含む、半導体装置の製造方法。
　［６］　上記［５］に記載の半導体装置の製造方法において、
　さらに、下記工程（Ｓ２）を含む、半導体装置の製造方法。
・工程（Ｓ２）：前記半導体ウエハを裏面側から研削する工程
　［７］　上記［６］に記載の半導体装置の製造方法において、
　さらに、下記工程（Ｓ３）を含む、半導体装置の製造方法。
・工程（Ｓ３）：前記半導体ウエハをダイシングして個片化する工程
　［８］　上記［６］に記載の半導体装置の製造方法において、
　前記半導体ウエハとして、表面側に溝が形成された半導体ウエハを用い、
　前記工程（Ｓ２）において、前記半導体ウエハを、前記溝を起点として複数のチップに個片化させる、製造方法。
　［９］　上記［６］に記載の半導体装置の製造方法において、
　前記半導体ウエハとして、内部に改質領域が形成された半導体ウエハを用いるか、又は、前記工程（Ｓ１）の後に前記半導体ウエハの内部に改質領域を形成し、
　前記工程（Ｓ２）において、前記半導体ウエハを、前記改質領域を起点として複数のチップに個片化させる、製造方法。 That is, the present invention relates to the following [1] to [7].
[1] It has a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order,
An adhesive tape for semiconductor processing, wherein the buffer layer satisfies both the following requirements (α) and the following requirements (β).
- Requirement (α): The breaking energy of the buffer layer at 23° C. is 15 MJ/m 3 or more.
・Requirement (β): When the buffer layer is subjected to a tensile test at a temperature of 23°C, the strain (ε 80 ) that is 80% of the breaking strain (ε 100 ) increases to the breaking strain (ε 100 ). , the stress increase gradient Δρ 80-100 is 30 MPa or more.
[2] The adhesive tape for semiconductor processing according to [1] above, wherein the base material satisfies the following requirement (γ).
- Requirement (γ): The product of the breaking strain (ε 100 ) at a temperature of 23°C and the breaking stress (ρ 100 ) at a temperature of 23°C is 60 MPa or more.
[3] The adhesive tape for semiconductor processing according to [1] or [2] above, wherein the adhesive layer has a thickness of less than 100 μm.
[4] A method of using the adhesive tape for semiconductor processing according to any one of [1] to [3] above, comprising:
A method of use in which the adhesive tape for semiconductor processing is affixed to the surface of the semiconductor wafer and the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer when back grinding the semiconductor wafer.
[5] A step of attaching the adhesive tape for semiconductor processing according to any one of [1] to [3] above to the surface of a semiconductor wafer, and cutting the adhesive tape for semiconductor processing along the outer periphery of the semiconductor wafer ( S1) A method for manufacturing a semiconductor device.
[6] In the method for manufacturing a semiconductor device according to [5] above,
Furthermore, a method for manufacturing a semiconductor device, including the following step (S2).
- Step (S2): Step of grinding the semiconductor wafer from the back side [7] In the method for manufacturing a semiconductor device according to [6] above,
Furthermore, a method for manufacturing a semiconductor device including the following step (S3).
- Step (S3): Step of dicing the semiconductor wafer into individual pieces [8] In the method for manufacturing a semiconductor device according to [6] above,
As the semiconductor wafer, a semiconductor wafer with grooves formed on the front side is used,
In the step (S2), the semiconductor wafer is singulated into a plurality of chips using the groove as a starting point.
[9] In the method for manufacturing a semiconductor device according to [6] above,
As the semiconductor wafer, a semiconductor wafer having a modified region formed therein is used, or a modified region is formed inside the semiconductor wafer after the step (S1),
In the step (S2), the semiconductor wafer is singulated into a plurality of chips starting from the modified region.
　本発明によれば、刃による切断性に優れる半導体加工用粘着テープを提供することが可能となる。 According to the present invention, it is possible to provide an adhesive tape for semiconductor processing that has excellent cuttability with a blade.
本発明の半導体加工用粘着テープの一例を示す概略断面図である。FIG. 1 is a schematic cross-sectional view showing an example of the adhesive tape for semiconductor processing of the present invention. 本発明の半導体装置の製造方法の工程概略図である。FIG. 2 is a process schematic diagram of a method for manufacturing a semiconductor device according to the present invention. Ａｂａｑｕｓによる解析モデルを示す図である。It is a figure which shows the analytical model by Abaqus. 「刃による切断性の評価（１）：シミュレーションによる評価」における実施例１ｓｉｍ．と比較例３ｓｉｍ．のＡｂａｑｕｓによる解析画像である。Example 1sim in "Evaluation of cutting performance by blade (1): Evaluation by simulation". and Comparative Example 3sim. This is an analysis image by Abaqus. 「刃による切断性の評価（２）：実験による評価」における実施例１ｅｘｐ．と比較例３ｅｘｐ．の断面の走査型電子顕微鏡（ＳＥＭ）の観察結果（図面代用写真）である。Example 1 exp in “Evaluation of cutting performance by blade (2): Evaluation by experiment”. and Comparative Example 3exp. This is a scanning electron microscope (SEM) observation result (photograph substituted for a drawing) of a cross section of.
　本明細書に記載された数値範囲の上限値および下限値は任意に組み合わせることができる。例えば、数値範囲として「Ａ～Ｂ」及び「Ｃ～Ｄ」が記載されている場合、「Ａ～Ｄ」及び「Ｃ～Ｂ」の数値範囲も、本発明の範囲に含まれる。
　本明細書に記載された数値範囲「下限値～上限値」は、特に断りのない限り、下限値以上、上限値以下であることを意味する。
　本明細書において、実施例の数値は、上限値又は下限値として用いられ得る数値である。 The upper and lower limits of the numerical ranges described herein can be arbitrarily combined. For example, when "A to B" and "C to D" are described as numerical ranges, the numerical ranges of "A to D" and "C to B" are also included in the scope of the present invention.
The numerical range "lower limit to upper limit" described in this specification means not less than the lower limit and not more than the upper limit, unless otherwise specified.
In this specification, the numerical values in Examples are numerical values that can be used as upper limits or lower limits.
　本明細書において、「（メタ）アクリレート」とは、「アクリレート」及び「メタクリレート」の両方を包含する概念であり、他の類似の用語についても同様である。例えば、「（メタ）アクリロイル基」とは、「アクリロイル基」及び「メタクリロイル基」の両方を包含する概念である。
　本明細書において、重量平均分子量及び数平均分子量は、ゲル・パーミエーション・クロマトグラフィー（ＧＰＣ）法により測定されるポリスチレン換算値である。 In this specification, "(meth)acrylate" is a concept that includes both "acrylate" and "methacrylate," and the same applies to other similar terms. For example, "(meth)acryloyl group" is a concept that includes both "acryloyl group" and "methacryloyl group."
In this specification, the weight average molecular weight and number average molecular weight are polystyrene equivalent values measured by gel permeation chromatography (GPC).
［半導体加工用粘着テープの態様］
　本発明の半導体加工用粘着テープは、緩衝層と、基材と、粘着剤層とがこの順で積層された積層構造を有する。そして、緩衝層が、下記要件（α）及び下記要件（β）の双方を満たす。
・要件（α）：前記緩衝層の２３℃における破断エネルギーが１５ＭＪ／ｍ３以上である。
・要件（β）：温度２３℃において前記緩衝層を引張試験に供したときに、破断ひずみ（ε１００）の８０％のひずみ（ε８０）が前記破断ひずみ（ε１００）に増加するまでの、応力の増加勾配Δρ８０－１００が、３０ＭＰａ以上である。 [Aspects of adhesive tape for semiconductor processing]
The adhesive tape for semiconductor processing of the present invention has a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order. The buffer layer satisfies both the following requirement (α) and the following requirement (β).
- Requirement (α): The breaking energy of the buffer layer at 23° C. is 15 MJ/m 3 or more.
・Requirement (β): When the buffer layer is subjected to a tensile test at a temperature of 23°C, the strain (ε 80 ) that is 80% of the breaking strain (ε 100 ) increases to the breaking strain (ε 100 ). , the stress increase gradient Δρ 80-100 is 30 MPa or more.
　図１に、本発明の半導体加工用粘着テープの一態様の断面模式図を示す。図１に示す半導体加工用粘着テープ１は、緩衝層１１と、基材１２と、粘着剤層１３とがこの順で積層された積層構造を有する。
　図１に示す半導体加工用粘着テープ１は、緩衝層１１と、基材１２と、粘着剤層１３とが、他の層を介することなく、直接積層されている。したがって、図１に示す半導体加工用粘着テープ１は、緩衝層１１、基材１２、及び粘着剤層１３のみから構成されている。 FIG. 1 shows a schematic cross-sectional view of one embodiment of the adhesive tape for semiconductor processing of the present invention. The adhesive tape 1 for semiconductor processing shown in FIG. 1 has a laminated structure in which a buffer layer 11, a base material 12, and an adhesive layer 13 are laminated in this order.
In the adhesive tape 1 for semiconductor processing shown in FIG. 1, a buffer layer 11, a base material 12, and an adhesive layer 13 are directly laminated without using any other layer. Therefore, the adhesive tape 1 for semiconductor processing shown in FIG. 1 is composed of only the buffer layer 11, the base material 12, and the adhesive layer 13.
　但し、半導体加工用粘着テープ１は、このような形態には必ずしも限定されない。例えば、緩衝層１１と基材１２との間、基材１２と粘着剤層１３との間の少なくともいずれかに、必要に応じて他の層が設けられていてもよい。当該他の層としては、例えばプライマー層、ウエハの回路面に形成されているバンプを埋め込むための層等が挙げられる。また、粘着剤層１３の表面には、使用時まで粘着剤層１３を保護するための剥離シートが積層されていてもよい。さらに、緩衝層１１の表面にはコート層が設けられていてもよい。
　なお、図１中、緩衝層１１、基材１２、及び粘着剤層１３は、それぞれ単層構造であるが、これらは多層構造であってもよい。 However, the adhesive tape 1 for semiconductor processing is not necessarily limited to such a form. For example, another layer may be provided between the buffer layer 11 and the base material 12, or between the base material 12 and the adhesive layer 13, if necessary. Examples of the other layers include a primer layer, a layer for embedding bumps formed on the circuit surface of the wafer, and the like. Furthermore, a release sheet may be laminated on the surface of the adhesive layer 13 to protect the adhesive layer 13 until use. Furthermore, a coating layer may be provided on the surface of the buffer layer 11.
In addition, although the buffer layer 11, the base material 12, and the adhesive layer 13 each have a single layer structure in FIG. 1, they may have a multilayer structure.
　以下、半導体加工用粘着テープの各部材の物性及び構成について、詳細に説明する。
　なお、以降の説明では、「半導体加工用粘着テープ」を、単に「粘着テープ」と略記することもある。 Hereinafter, the physical properties and structure of each member of the adhesive tape for semiconductor processing will be explained in detail.
In addition, in the following description, "adhesive tape for semiconductor processing" may be simply abbreviated as "adhesive tape."
［緩衝層］
　緩衝層は、半導体ウエハの裏面研削時の応力を緩和して、半導体ウエハに割れ及び欠けが生じることを防止する機能を有する。また、半導体ウエハに粘着テープを貼付し、半導体ウエハの外周に沿って粘着テープが切断された後、半導体ウエハは粘着テープを介してチャックテーブル上に配置され裏面研削されるが、粘着テープが緩衝層を有することで、半導体ウエハがチャックテーブルに適切に保持されやすくなる。このように、半導体ウエハの裏面研削を行う場合、粘着テープが緩衝層を有することによって、多大な利点がある。
　しかし、その一方で、緩衝層が基材と比較して軟質であるが故に、欠点も存在する。具体的には、粘着テープの切断時に緩衝層の樹脂が撚れ等を起こし、切断面が荒れて、カットダストが発生することがある。 [Buffer layer]
The buffer layer has a function of alleviating stress during backside grinding of the semiconductor wafer and preventing cracks and chips from occurring in the semiconductor wafer. In addition, adhesive tape is attached to the semiconductor wafer, and after the adhesive tape is cut along the outer periphery of the semiconductor wafer, the semiconductor wafer is placed on a chuck table via the adhesive tape and the back surface is ground. Having the layer helps the semiconductor wafer to be properly held on the chuck table. As described above, when performing backside grinding of a semiconductor wafer, the adhesive tape having a buffer layer has great advantages.
However, on the other hand, there are also drawbacks because the buffer layer is softer than the base material. Specifically, when cutting the adhesive tape, the resin of the buffer layer may become twisted, resulting in rough cut surfaces and generation of cut dust.
　本発明者らは、上記欠点を解消すべく熟慮を重ねた結果、粘着テープの刃による切断性を高めて、緩衝層の切断面の荒れを抑制することが、カットダストの抑制に有効であるとの考えに至り、鋭意検討を行った。その結果、緩衝層の破断エネルギーと、緩衝層の応力－ひずみ線図における破断点近傍の応力の増加勾配とに着目することによって、緩衝層の刃による切断性を優れたものとできることを見出した。そして、さらに検討を重ねて、上記要件（α）及び上記要件（β）を特定するに至った。 As a result of careful consideration in order to eliminate the above-mentioned drawbacks, the present inventors found that it is effective to suppress cut dust by increasing the cutting performance of the adhesive tape blade and suppressing the roughness of the cut surface of the buffer layer. We came up with this idea and conducted a thorough study. As a result, they found that by focusing on the fracture energy of the buffer layer and the gradient of increase in stress near the break point in the stress-strain diagram of the buffer layer, it was possible to improve the cutting performance of the buffer layer with the blade. . After further consideration, the above requirement (α) and the above requirement (β) were identified.
＜要件（α）＞
　要件（α）では、緩衝層の２３℃における破断エネルギーが１５ＭＪ／ｍ３以上であることを規定している。緩衝層の２３℃における破断エネルギーが１５ＭＪ／ｍ３以上であり、且つ緩衝層が要件（β）も満たすことで、緩衝層の刃による切断性を優れたものとできる。緩衝層の２３℃における破断エネルギーが１５ＭＪ／ｍ３以上であると、緩衝層は、刃が当たっても変形し難く、緩衝層の撚れ等が抑制され、切断性が良好になるものと推察される。
　なお、緩衝層の２３℃における破断エネルギーが１５ＭＪ／ｍ３未満であると、緩衝層の刃による切断性を優れたものとできない。
　ここで、緩衝層の刃による切断性をより優れたものとしやすくする観点から、緩衝層の２３℃における破断エネルギーは、好ましくは１７ＭＪ／ｍ３以上、より好ましくは２２ＭＪ／ｍ３以上、更に好ましくは２７ＭＪ／ｍ３以上である。
　また、刃の摩耗を防ぐ観点から、緩衝層の２３℃における破断エネルギーは、好ましくは１５０ＭＪ／ｍ３以下である。
　なお、緩衝層の２３℃における破断エネルギーは、ＪＩＳ　Ｋ７１６１：１９９４及びＪＩＳ　Ｋ７１２７：１９９９に基づく２３℃における引張試験により得られる、応力とひずみとを線図化した応力－ひずみ線図において、破断点までを積分した値である。ひずみは、初期の試験片長さ（ｍｍ）×伸度（％）により求めることができる。なお、後述する破断応力及び破断ひずみは、それぞれ上記引張試験における破断時（破断点）の応力及びひずみである。 <Requirements (α)>
Requirement (α) stipulates that the breaking energy of the buffer layer at 23° C. is 15 MJ/m 3 or more. When the breaking energy of the buffer layer at 23° C. is 15 MJ/m 3 or more and the buffer layer also satisfies the requirement (β), the buffer layer can have excellent cutting properties with a blade. It is presumed that when the breaking energy of the buffer layer at 23°C is 15 MJ/ m3 or more, the buffer layer is difficult to deform even when hit by a blade, the twisting etc. of the buffer layer is suppressed, and the cutting performance is improved. be done.
Note that if the breaking energy of the buffer layer at 23° C. is less than 15 MJ/m 3 , the buffer layer cannot have excellent cutting properties with a blade.
Here, from the viewpoint of making it easier to improve the cutting properties of the buffer layer by the blade, the breaking energy of the buffer layer at 23° C. is preferably 17 MJ/m 3 or more, more preferably 22 MJ/m 3 or more, and even more preferably is 27 MJ/m 3 or more.
Further, from the viewpoint of preventing blade wear, the breaking energy of the buffer layer at 23° C. is preferably 150 MJ/m 3 or less.
The breaking energy of the buffer layer at 23°C is determined by the breaking point in the stress-strain diagram, which is a diagram of stress and strain, obtained by a tensile test at 23°C based on JIS K7161:1994 and JIS K7127:1999. This is the value obtained by integrating up to . Strain can be determined by initial test piece length (mm) x elongation (%). In addition, the breaking stress and breaking strain mentioned later are the stress and strain at the time of breaking (breaking point) in the above-mentioned tensile test, respectively.
＜要件（β）＞
　要件（β）では、温度２３℃において緩衝層を引張試験に供したときに、破断ひずみ（ε１００）の８０％のひずみ（ε８０）が前記破断ひずみ（ε１００）に増加するまでの、応力の増加勾配Δρ８０－１００が、３０ＭＰａ以上であることを規定している。応力の増加勾配Δρ８０－１００が、３０ＭＰａ以上であると、加工硬化（ひずみ硬化）によって、刃による切断の過程で緩衝層の硬化の度合いが向上し、刃による切断時に緩衝層の変形（伸び）が抑制される。そのため、緩衝層の撚れ等が抑制され、切断性が良好になるものと推察される。
　なお、緩衝層の応力の増加勾配Δρ８０－１００が、３０ＭＰａ未満であると、緩衝層の刃による切断性を優れたものとできない。
　ここで、緩衝層の刃による切断性をより優れたものとする観点から、応力の増加勾配Δρ８０－１００は、好ましくは５０ＭＰａ以上、より好ましくは７０ＭＰａ以上、更に好ましくは７５ＭＰａ以上、より更に好ましくは８０ＭＰａ以上、更になお好ましくは８５ＭＰａ以上、一層好ましくは９０ＭＰａ以上、より一層好ましくは９５ＭＰａ以上、更に一層好ましくは１００ＭＰａ以上である。また、応力の増加勾配Δρ８０－１００は、通常、２００ＭＰａ以下である。 <Requirements (β)>
The requirement (β) is that when the buffer layer is subjected to a tensile test at a temperature of 23° C., until the strain (ε 80 ) that is 80% of the breaking strain (ε 100 ) increases to the breaking strain (ε 100 ), It is specified that the stress increase gradient Δρ 80-100 is 30 MPa or more. When the stress increase gradient Δρ 80-100 is 30 MPa or more, the degree of hardening of the buffer layer increases during the cutting process with the blade due to work hardening (strain hardening), and the deformation (elongation) of the buffer layer during cutting with the blade increases. ) is suppressed. Therefore, it is presumed that twisting of the buffer layer is suppressed and the cutting properties are improved.
Note that if the stress increase gradient Δρ 80-100 of the buffer layer is less than 30 MPa, the buffer layer cannot be cut easily by the blade.
Here, from the viewpoint of improving the cutting properties of the buffer layer with the blade, the stress increase gradient Δρ 80-100 is preferably 50 MPa or more, more preferably 70 MPa or more, still more preferably 75 MPa or more, and even more preferably is 80 MPa or more, even more preferably 85 MPa or more, even more preferably 90 MPa or more, even more preferably 95 MPa or more, even more preferably 100 MPa or more. Further, the stress increase gradient Δρ 80-100 is usually 200 MPa or less.
＜他の物性値＞
　緩衝層は、基材と比較して軟質の層である。これにより、半導体ウエハの裏面研削時の応力が適切に緩和される。
　なお、半導体ウエハの裏面研削時の応力をより適切に緩和しやすくする観点から、緩衝層の２３℃における弾性率は、好ましくは１，２００ＭＰａ以下、より好ましくは１，０００ＭＰａ以下、更に好ましくは８００ＭＰａ以下、より更に好ましくは７００ＭＰａ以下、更になお好ましくは５００ＭＰａ以下である。 <Other physical property values>
The buffer layer is a soft layer compared to the base material. As a result, stress during backside grinding of the semiconductor wafer is appropriately alleviated.
In addition, from the viewpoint of facilitating more appropriate relaxation of stress during backside grinding of a semiconductor wafer, the elastic modulus of the buffer layer at 23°C is preferably 1,200 MPa or less, more preferably 1,000 MPa or less, and even more preferably 800 MPa. Below, it is still more preferably 700 MPa or less, still more preferably 500 MPa or less.
　また、上記の破断エネルギー及び応力の増加勾配Δρ８０－１００を得やすくする観点から、緩衝層の破断応力は、好ましくは３０ＭＰａ以上、より好ましくは５０ＭＰａ以上、更に好ましくは５５ＭＰａ以上、より更に好ましくは６０ＭＰａ以上である。
　さらに、応力の増加勾配Δρ８０－１００を得やすくする観点から、緩衝層の破断ひずみ（ε１００）は、好ましくは０．５０以上、より好ましくは１．０以上、更に好ましくは１．１以上、より更に好ましくは１．２以上、更になお好ましくは１．３以上、一層好ましくは１．４以上である。 Further, from the viewpoint of easily obtaining the above-mentioned fracture energy and stress increase gradient Δρ 80-100 , the fracture stress of the buffer layer is preferably 30 MPa or more, more preferably 50 MPa or more, still more preferably 55 MPa or more, and even more preferably It is 60 MPa or more.
Furthermore, from the viewpoint of easily obtaining the stress increase gradient Δρ 80-100 , the breaking strain (ε 100 ) of the buffer layer is preferably 0.50 or more, more preferably 1.0 or more, and even more preferably 1.1 or more. , even more preferably 1.2 or more, even more preferably 1.3 or more, even more preferably 1.4 or more.
＜緩衝層の厚さ＞
　緩衝層の厚さは、半導体ウエハの裏面研削時の応力を適切に緩和する観点から、好ましくは１μｍ～１００μｍ、より好ましくは５μｍ～８０μｍ、更に好ましくは１０μｍ～６０μｍである。 <Thickness of buffer layer>
The thickness of the buffer layer is preferably 1 μm to 100 μm, more preferably 5 μm to 80 μm, and even more preferably 10 μm to 60 μm, from the viewpoint of appropriately relieving stress during backside grinding of a semiconductor wafer.
＜緩衝層の構成＞
　緩衝層は、半導体ウエハの裏面研削時の応力を適切に緩和する機能を有し、且つ上記要件（α）及び上記要件（β）を満たすものであれば、特に制限なく用いることができるが、本発明の効果をより発揮させやすくする観点から、緩衝層は、エネルギー線重合性化合物を含む緩衝層形成用組成物の硬化物であることが好ましい。
　以下、エネルギー線重合性化合物を含む緩衝層形成用組成物から形成される層に含まれる各成分について順に説明する。 <Structure of buffer layer>
The buffer layer can be used without particular restrictions as long as it has the function of appropriately relieving stress during backside grinding of a semiconductor wafer and satisfies the above requirements (α) and (β). From the viewpoint of making it easier to exhibit the effects of the present invention, the buffer layer is preferably a cured product of a composition for forming a buffer layer containing an energy ray polymerizable compound.
Hereinafter, each component contained in the layer formed from the composition for forming a buffer layer containing an energy beam polymerizable compound will be explained in order.
＜＜エネルギー線重合性化合物を含む緩衝層形成用組成物から形成される層＞＞
　エネルギー線重合性化合物を含む緩衝層形成用組成物は、エネルギー線が照射されることで硬化する。
　本明細書において、「エネルギー線」とは、電磁波又は荷電粒子線の中でエネルギー量子を有するものを意味する。エネルギー線の例としては、紫外線、放射線、電子線等が挙げられる。紫外線は、例えば、紫外線源として高圧水銀ランプ、ヒュージョンランプ、キセノンランプ、ブラックライト又はＬＥＤランプ等を用いることで照射できる。電子線は、電子線加速器等によって発生させたものを照射できる。
　エネルギー線重合性化合物を含む緩衝層形成用組成物は、より具体的には、ウレタン（メタ）アクリレート（ａ１）を含むことが好ましい。緩衝層形成用組成物は、上記（ａ１）成分を含有することで、緩衝層の破断エネルギーを上記範囲に調整しやすい。
　また、緩衝層形成用組成物は、上記（ａ１）に加えて、環形成原子数６～２０の脂環基又は複素環基を有する重合性化合物（ａ２）及び官能基を有する重合性化合物（ａ３）から選択される１種以上を含有することがより好ましい。
　また、緩衝層形成用組成物は、上記（ａ１）～（ａ３）成分に加えて、多官能重合性化合物（ａ４）を含有してもよい。
　さらに、緩衝層形成用組成物は光重合開始剤を含有することが好ましく、本発明の効果を損なわない範囲において、その他の添加剤や樹脂成分を含有してもよい。
　以下、エネルギー線重合性化合物を含む緩衝層形成用組成物中に含まれる各成分について詳細に説明する。 <<Layer formed from a buffer layer forming composition containing an energy beam polymerizable compound>>
A composition for forming a buffer layer containing an energy ray polymerizable compound is cured by being irradiated with energy rays.
As used herein, the term "energy ray" refers to electromagnetic waves or charged particle beams that have energy quanta. Examples of energy rays include ultraviolet rays, radiation, electron beams, and the like. The ultraviolet rays can be irradiated using, for example, a high-pressure mercury lamp, fusion lamp, xenon lamp, black light, or LED lamp as an ultraviolet source. The electron beam can be generated by an electron beam accelerator or the like.
More specifically, the composition for forming a buffer layer containing an energy beam polymerizable compound preferably contains urethane (meth)acrylate (a1). By containing the component (a1), the composition for forming a buffer layer can easily adjust the breaking energy of the buffer layer to the above range.
In addition to the above (a1), the composition for forming a buffer layer also contains a polymerizable compound (a2) having an alicyclic group or a heterocyclic group having 6 to 20 ring atoms and a polymerizable compound having a functional group ( It is more preferable to contain one or more selected from a3).
Further, the composition for forming a buffer layer may contain a polyfunctional polymerizable compound (a4) in addition to the components (a1) to (a3) described above.
Furthermore, the composition for forming a buffer layer preferably contains a photopolymerization initiator, and may contain other additives and resin components within a range that does not impair the effects of the present invention.
Each component contained in the composition for forming a buffer layer containing an energy beam polymerizable compound will be described in detail below.
（ウレタン（メタ）アクリレート（ａ１））
　ウレタン（メタ）アクリレート（ａ１）とは、少なくとも（メタ）アクリロイル基及びウレタン結合を有する化合物であり、エネルギー線照射により重合硬化する性質を有するものである。ウレタン（メタ）アクリレート（ａ１）は、オリゴマーまたはポリマーであり、本実施形態ではオリゴマーが好ましい。
　なお、以降の説明では、「ウレタン（メタ）アクリレート（ａ１）」を「成分（ａ１）」ともいう。 (Urethane (meth)acrylate (a1))
Urethane (meth)acrylate (a1) is a compound having at least a (meth)acryloyl group and a urethane bond, and has the property of being polymerized and cured by energy ray irradiation. Urethane (meth)acrylate (a1) is an oligomer or a polymer, and in this embodiment, an oligomer is preferred.
In addition, in the following description, "urethane (meth)acrylate (a1)" is also referred to as "component (a1)."
　成分（ａ１）の重量平均分子量（Ｍｗ）は、好ましくは１，０００～１００，０００、より好ましくは２，０００～６０，０００、更に好ましくは２，０００～１０，０００未満である。
　また、成分（ａ１）中の（メタ）アクリロイル基数（以下、「官能基数」ともいう）としては、単官能、２官能、もしくは３官能以上でもよいが、単官能又は２官能であることが好ましい。
　成分（ａ１）は、例えば、ポリオール化合物と、多価イソシアネート化合物とを反応させて得られる末端イソシアネートウレタンプレポリマーに、ヒドロキシル基を有する（メタ）アクリレートを反応させて得ることができる。なお、成分（ａ１）は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 The weight average molecular weight (Mw) of component (a1) is preferably from 1,000 to 100,000, more preferably from 2,000 to 60,000, even more preferably from 2,000 to less than 10,000.
The number of (meth)acryloyl groups (hereinafter also referred to as "functional group number") in component (a1) may be monofunctional, bifunctional, or trifunctional or more, but monofunctional or difunctional is preferable. .
Component (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 hydroxyl group. In addition, the component (a1) may be used alone or in combination of two or more.
　成分（ａ１）の原料となるポリオール化合物は、ヒドロキシ基を２つ以上有する化合物であれば特に限定されない。具体的なポリオール化合物としては、例えば、アルキレンジオール、ポリエーテル型ポリオール、ポリエステル型ポリオール、ポリカーボネート型ポリオール等が挙げられる。これらの中でも、ポリエステル型ポリオール又はポリカーボネート型ポリオールが好ましい。
　なお、ポリオール化合物としては、２官能のジオール、３官能のトリオール、４官能以上のポリオールのいずれであってもよいが、２官能のジオールが好ましく、ポリエステル型ジオールまたはポリカーボネート型ジオールがより好ましい。 The polyol compound serving as a raw material for component (a1) 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, and polycarbonate polyols. Among these, polyester type polyols or polycarbonate type polyols are preferred.
The polyol compound may be any of bifunctional diols, trifunctional triols, and tetrafunctional or higher functional polyols, but bifunctional diols are preferred, and polyester diols or polycarbonate diols are more preferred.
　多価イソシアネート化合物としては、例えば、テトラメチレンジイソシアネート、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系ポリイソシアネート類；イソホロンジイソシアネート、ノルボルナンジイソシアネート、ジシクロヘキシルメタン－４，４’－ジイソシアネート、ジシクロヘキシルメタン－２，４’－ジイソシアネート、ω，ω’－ジイソシアネートジメチルシクロヘキサン等の脂環族系ジイソシアネート類；４，４’－ジフェニルメタンジイソシアネート、トリレンジイソシアネート、キシリレンジイソシアネート、トリジンジイソシアネート、テトラメチレンキシリレンジイソシアネート、ナフタレン－１，５－ジイソシアネート等の芳香族系ジイソシアネート類等が挙げられる。
　これらの中でも、イソホロンジイソシアネート、ヘキサメチレンジイソシアネート、キシリレンジイソシアネートが好ましい。 Examples of polyvalent isocyanate compounds include aliphatic polyisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate; isophorone diisocyanate, norbornane diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and dicyclohexylmethane-2 , 4'-diisocyanate, ω, ω'-diisocyanate, alicyclic diisocyanates such as dimethylcyclohexane; 4,4'-diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, toridine diisocyanate, tetramethylene xylylene diisocyanate, naphthalene. Examples include aromatic diisocyanates such as 1,5-diisocyanate.
Among these, isophorone diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are preferred.
　上述のポリオール化合物と、多価イソシアネート化合物とを反応させて得られる末端イソシアネートウレタンプレポリマーに、ヒドロキシ基を有する（メタ）アクリレートを反応させてウレタン（メタ）アクリレート（ａ１）を得ることができる。ヒドロキシ基を有する（メタ）アクリレートとしては、少なくとも１分子中にヒドロキシ基及び（メタ）アクリロイル基を有する化合物であれば、特に限定されない。 Urethane (meth)acrylate (a1) can be obtained by reacting a (meth)acrylate having a hydroxy group with a terminal isocyanate urethane prepolymer obtained by reacting the above-mentioned polyol compound and a polyvalent isocyanate compound. The (meth)acrylate having a hydroxy group is not particularly limited as long as it is a compound having a hydroxy group and a (meth)acryloyl group in at least one molecule.
　具体的なヒドロキシ基を有する（メタ）アクリレートとしては、例えば、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシシクロヘキシル（メタ）アクリレート、５－ヒドロキシシクロオクチル（メタ）アクリレート、２－ヒドロキシ－３－フェニルオキシプロピル（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ポリエチレングリコールモノ（メタ）アクリレート、ポリプロピレングリコールモノ（メタ）アクリレート等のヒドロキシアルキル（メタ）アクリレート；Ｎ－メチロール（メタ）アクリルアミド等のヒドロキシ基含有（メタ）アクリルアミド；ビニルアルコール、ビニルフェノール、ビスフェノールＡのジグリシジルエステルに（メタ）アクリル酸を反応させて得られる反応物；等が挙げられる。
　これらの中でも、ヒドロキシアルキル（メタ）アクリレートが好ましく、２－ヒドロキシエチル（メタ）アクリレートがより好ましい。 Specific examples of (meth)acrylates having a hydroxy group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 4-hydroxycyclohexyl (meth)acrylate. Acrylate, 5-hydroxycyclooctyl (meth)acrylate, 2-hydroxy-3-phenyloxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, etc. hydroxyalkyl (meth)acrylate; hydroxy group-containing (meth)acrylamide such as N-methylol (meth)acrylamide; reaction obtained by reacting diglycidyl ester of vinyl alcohol, vinylphenol, or bisphenol A with (meth)acrylic acid things; etc.
Among these, hydroxyalkyl (meth)acrylate is preferred, and 2-hydroxyethyl (meth)acrylate is more preferred.
　末端イソシアネートウレタンプレポリマー及びヒドロキシ基を有する（メタ）アクリレートを反応させる条件としては、必要に応じて添加される溶剤、触媒の存在下、６０℃～１００℃で、１時間～４時間反応させる条件が好ましい。
　緩衝層形成用組成物中の成分（ａ１）の含有量は、緩衝層形成用組成物の全量（１００質量％）に対して、好ましくは１０質量％～８０質量％、より好ましくは３０質量％～８０質量％、更に好ましくは４０質量％～８０質量％である。 Conditions for reacting the terminal isocyanate urethane prepolymer and the (meth)acrylate having a hydroxyl group include conditions for reacting at 60° C. to 100° C. for 1 hour to 4 hours in the presence of a solvent and catalyst added as necessary. is preferred.
The content of component (a1) in the composition for forming a buffer layer is preferably 10% by mass to 80% by mass, more preferably 30% by mass, based on the total amount (100% by mass) of the composition for forming a buffer layer. ~80% by weight, more preferably 40% by weight ~ 80% by weight.
（環形成原子数６～２０の脂環基又は複素環基を有する重合性化合物（ａ２））
　環形成原子数６～２０の脂環基又は複素環基を有する重合性化合物（ａ２）（以下、「成分（ａ２」ともいう）は、環形成原子数６～２０の脂環基又は複素環基を有する重合性化合物であり、さらには、少なくとも１つの（メタ）アクリロイル基を有する化合物であることが好ましく、より好ましくは１つの（メタ）アクリロイル基を有する化合物である。成分（ａ２）を用いることで、得られる緩衝層形成用組成物の成膜性を向上させることができる。 (Polymerizable compound (a2) having an alicyclic group or a heterocyclic group having 6 to 20 ring atoms)
The polymerizable compound (a2) having an alicyclic group or a heterocyclic group having 6 to 20 ring atoms (hereinafter also referred to as "component (a2")) is an alicyclic group or a heterocyclic group having 6 to 20 ring atoms. It is a polymerizable compound having a group, more preferably a compound having at least one (meth)acryloyl group, more preferably a compound having one (meth)acryloyl group.Component (a2) By using it, the film-forming properties of the resulting composition for forming a buffer layer can be improved.
　なお、成分（ａ２）の定義と、後述する成分（ａ３）の定義とは重複する部分があるが、重複部分は成分（ａ３）に含まれる。例えば、少なくとも１つの（メタ）アクリロイル基と、環形成原子数６～２０の脂環基又は複素環基と、水酸基、エポキシ基、アミド基、アミノ基等の官能基とを有する化合物は、成分（ａ２）と成分（ａ３）の両方の定義に含まれるが、本発明において当該化合物は、成分（ａ３）に含まれるものとする。 Note that there is some overlap between the definition of component (a2) and the definition of component (a3) described below, but the overlap is included in component (a3). For example, a compound having at least one (meth)acryloyl group, an alicyclic group or a heterocyclic group having 6 to 20 ring atoms, and a functional group such as a hydroxyl group, an epoxy group, an amide group, or an amino group may be used as a component. Although it is included in the definition of both (a2) and component (a3), the compound is included in component (a3) in the present invention.
　成分（ａ２）が有する脂環基又は複素環基の環形成原子数は、好ましくは６～２０であるが、より好ましくは６～１８、さらに好ましくは６～１６である。当該複素環基の環構造を形成する原子としては、例えば、炭素原子、窒素原子、酸素原子、硫黄原子等が挙げられる。
　なお、環形成原子数とは、原子が環状に結合した構造の化合物の当該環自体を構成する原子の数を表し、環を構成しない原子（例えば、環を構成する原子に結合した水素原子）や、当該環が置換基によって置換される場合の置換基に含まれる原子は環形成原子数には含まない。 The number of ring atoms of the alicyclic group or heterocyclic group contained in component (a2) is preferably 6 to 20, more preferably 6 to 18, and still more preferably 6 to 16. Examples of atoms forming the ring structure of the heterocyclic group include carbon atoms, nitrogen atoms, oxygen atoms, and sulfur atoms.
Note that the number of ring-forming atoms refers to the number of atoms that make up the ring itself of a compound with a structure in which atoms are bonded in a ring, and refers to atoms that do not make up a ring (for example, hydrogen atoms bonded to atoms that make up a ring). In the case where the ring is substituted with a substituent, atoms included in the substituent are not included in the number of ring atoms.
　具体的な成分（ａ２）としては、例えば、イソボルニル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、ジシクロペンテニルオキシ（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、アダマンタン（メタ）アクリレート等の脂環基含有（メタ）アクリレート；テトラヒドロフルフリル（メタ）アクリレート、モルホリン（メタ）アクリレート等の複素環基含有（メタ）アクリレート；等が挙げられる。
　なお、成分（ａ２）は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。
　脂環基含有（メタ）アクリレートの中ではイソボルニル（メタ）アクリレートが好ましく、複素環基含有（メタ）アクリレートの中ではテトラヒドロフルフリル（メタ）アクリレートが好ましい。 Specific examples of component (a2) include isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyloxy (meth)acrylate, cyclohexyl (meth)acrylate, Alicyclic group-containing (meth)acrylates such as adamantane (meth)acrylate; heterocyclic group-containing (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate and morpholine (meth)acrylate; and the like.
In addition, the component (a2) may be used alone or in combination of two or more.
Among the alicyclic group-containing (meth)acrylates, isobornyl (meth)acrylate is preferred, and among the heterocyclic group-containing (meth)acrylates, tetrahydrofurfuryl (meth)acrylate is preferred.
　緩衝層形成用組成物が成分（ａ２）を含む場合、緩衝層形成用組成物中の成分（ａ２）の含有量は、緩衝層形成用組成物の全量（１００質量％）に対して、好ましくは１０質量％～８０質量％、より好ましくは２０質量％～７０質量％である。 When the composition for forming a buffer layer contains component (a2), the content of component (a2) in the composition for forming a buffer layer is preferably based on the total amount (100% by mass) of the composition for forming a buffer layer. is 10% by mass to 80% by mass, more preferably 20% by mass to 70% by mass.
（官能基を有する重合性化合物（ａ３））
　官能基を有する重合性化合物（ａ３）（以下、「成分（ａ３）」ともいう）は、水酸基、エポキシ基、アミド基、アミノ基等の官能基を含有する重合性化合物であり、さらには、少なくとも１つの（メタ）アクリロイル基を有する化合物であることが好ましく、より好ましくは１つの（メタ）アクリロイル基を有する化合物である。
　成分（ａ３）は、成分（ａ１）との相溶性が良好であり、緩衝層形成用組成物の粘度を適度な範囲に調整しやすくなる。また、当該組成物から形成される緩衝層の破断エネルギーを上記範囲に調整しやすくなり、緩衝層を比較的薄くしても緩衝性能が良好になる。
　成分（ａ３）としては、例えば、水酸基含有（メタ）アクリレート、エポキシ基含有化合物、アミド基含有化合物、アミノ基含有（メタ）アクリレート等が挙げられる。 (Polymerizable compound (a3) having a functional group)
The polymerizable compound (a3) having a functional group (hereinafter also referred to as "component (a3)") is a polymerizable compound containing a functional group such as a hydroxyl group, an epoxy group, an amide group, an amino group, and further, A compound having at least one (meth)acryloyl group is preferable, and a compound having one (meth)acryloyl group is more preferable.
Component (a3) has good compatibility with component (a1), making it easy to adjust the viscosity of the buffer layer forming composition to an appropriate range. Furthermore, the breaking energy of the buffer layer formed from the composition can be easily adjusted within the above range, and even if the buffer layer is made relatively thin, the buffering performance can be improved.
Examples of component (a3) include hydroxyl group-containing (meth)acrylates, epoxy group-containing compounds, amide group-containing compounds, amino group-containing (meth)acrylates, and the like.
　水酸基含有（メタ）アクリレートとしては、例えば、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、３－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、フェニルヒドロキシプロピル（メタ）アクリレート、シクロヘキサノール（メタ）アクリレート、４－ｔｅｒｔ－ブチルシクロヘキサノールアクリレート、２－ヒドロキシ－３－フェノキシプロピルアクリレート等が挙げられる。
　エポキシ基含有化合物としては、例えば、グリシジル（メタ）アクリレート、メチルグリシジル（メタ）アクリレート、アリルグリシジルエーテル等が挙げられ、これらの中では、グリシジル（メタ）アクリレート、メチルグリシジル（メタ）アクリレート等のエポキシ基含有（メタ）アクリレートが好ましい。
　アミド基含有化合物としては、例えば、（メタ）アクリルアミド、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ－ブチル（メタ）アクリルアミド、Ｎ－メチロール（メタ）アクリルアミド、Ｎ－メチロールプロパン（メタ）アクリルアミド、Ｎ－メトキシメチル（メタ）アクリルアミド、Ｎ－ブトキシメチル（メタ）アクリルアミド等が挙げられる。
　アミノ基含有（メタ）アクリレートとしては、例えば、第１級アミノ基含有（メタ）アクリレート、第２級アミノ基含有（メタ）アクリレート、第３級アミノ基含有（メタ）アクリレート等が挙げられる。 Examples of hydroxyl group-containing (meth)acrylates include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxy Butyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, phenylhydroxypropyl (meth)acrylate, cyclohexanol (meth)acrylate, 4-tert-butylcyclohexanol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, etc. Can be mentioned.
Examples of epoxy group-containing compounds include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and allylglycidyl ether. Group-containing (meth)acrylates are preferred.
Examples of the amide group-containing compound include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylolpropane(meth)acrylamide, and N-methylol(meth)acrylamide. -methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide and the like.
Examples of the amino group-containing (meth)acrylate include primary amino group-containing (meth)acrylate, secondary amino group-containing (meth)acrylate, and tertiary amino group-containing (meth)acrylate.
　これらの中でも、水酸基含有（メタ）アクリレートが好ましく、フェニルヒドロキシプロピル（メタ）アクリレート等の芳香環を有する水酸基含有（メタ）アクリレート、シクロヘキサノール（メタ）アクリレート、４－ｔｅｒｔ－ブチルシクロヘキサノールアクリレート等の脂環式環を有する水酸基含有（メタ）アクリレートがより好ましく、脂環式環を有する水酸基含有（メタ）アクリレートが更に好ましい。当該脂環式環の環形成炭素数は、好ましくは６～２０、より好ましくは６～１８、更に好ましくは６～１６である。
　なお、成分（ａ３）は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 Among these, hydroxyl group-containing (meth)acrylates are preferred, and hydroxyl group-containing (meth)acrylates having an aromatic ring such as phenylhydroxypropyl (meth)acrylate, cyclohexanol (meth)acrylate, 4-tert-butylcyclohexanol acrylate, etc. Hydroxyl group-containing (meth)acrylates having an alicyclic ring are more preferred, and hydroxyl group-containing (meth)acrylates having an alicyclic ring are even more preferred. The number of carbon atoms forming the alicyclic ring is preferably 6 to 20, more preferably 6 to 18, and still more preferably 6 to 16.
In addition, component (a3) may be used singly or in combination of two or more.
　緩衝層形成用組成物が成分（ａ３）を含む場合、緩衝層形成用組成物中の成分（ａ３）の含有量は、緩衝層の破断エネルギーを上記範囲に調整しやすくする観点、緩衝層形成用組成物の成膜性を向上させやすくする観点から、緩衝層形成用組成物の全量（１００質量％）に対して、好ましくは５質量％～５０質量％、より好ましくは１０質量％～４０質量％、更に好ましくは２０質量％～３０質量％である。
　また、緩衝層形成用組成物が成分（ａ２）及び（ａ３）の双方を含む場合、緩衝層形成用組成物中の成分（ａ２）と成分（ａ３）との含有量比［（ａ２）／（ａ３）］は、質量比で、好ましくは０．５～３．０、より好ましくは１．０～３．０、更に好ましくは１．３～３．０、より更に好ましくは１．５～２．８である。
　なお、上記要件（α）及び（β）を満たす緩衝層を調製しやすくする観点から、緩衝層形成用組成物は成分（ａ３）を含むことが好ましく、当該成分（ａ３）としては、脂環式環を有する水酸基含有（メタ）アクリレートであることが好ましい。 When the composition for forming a buffer layer contains component (a3), the content of component (a3) in the composition for forming a buffer layer is determined from the viewpoint of easily adjusting the breaking energy of the buffer layer within the above range, and from the viewpoint of forming the buffer layer. From the viewpoint of easily improving the film formability of the composition for forming a buffer layer, preferably 5% to 50% by mass, more preferably 10% to 40% by mass, based on the total amount (100% by mass) of the composition for forming a buffer layer. % by mass, more preferably 20% by mass to 30% by mass.
Further, when the composition for forming a buffer layer contains both components (a2) and (a3), the content ratio of component (a2) and component (a3) in the composition for forming a buffer layer [(a2)/ (a3)] is preferably 0.5 to 3.0, more preferably 1.0 to 3.0, even more preferably 1.3 to 3.0, even more preferably 1.5 to 3.0, in terms of mass ratio. It is 2.8.
In addition, from the viewpoint of facilitating the preparation of a buffer layer that satisfies the above requirements (α) and (β), the composition for forming a buffer layer preferably contains a component (a3), and the component (a3) is an alicyclic A hydroxyl group-containing (meth)acrylate having a formula ring is preferable.
（多官能重合性化合物（ａ４））
　多官能重合性化合物（ａ４）（以下、「成分（ａ４）」ともいう）とは、光重合性不飽和基を２つ以上有する化合物をいう。光重合性不飽和基は、炭素－炭素二重結合を含む官能基であり、例えば、（メタ）アクリロイル基、ビニル基、アリル基、ビニルベンジル基等が挙げられる。光重合性不飽和基は２種以上を組み合わせてもよい。多官能重合性化合物中の光重合性不飽和基と成分（ａ１）中の（メタ）アクリロイル基とが反応したり、成分（ａ４）中の光重合性不飽和基同士が反応したりすることで、三次元網目構造（架橋構造）が形成される。多官能重合性化合物を使用すると、光重合性不飽和基を１つしか含まない化合物を使用した場合と比較して、エネルギー線照射により形成される架橋構造が増加するため、緩衝層が特異な粘弾性を示し、破断エネルギーを上記範囲に調整しやすくなる。 (Polyfunctional polymerizable compound (a4))
The polyfunctional polymerizable compound (a4) (hereinafter also referred to as "component (a4)") refers to a compound having two or more photopolymerizable unsaturated groups. The photopolymerizable unsaturated group is a functional group containing a carbon-carbon double bond, and includes, for example, a (meth)acryloyl group, a vinyl group, an allyl group, a vinylbenzyl group, and the like. Two or more types of photopolymerizable unsaturated groups may be used in combination. The photopolymerizable unsaturated group in the polyfunctional polymerizable compound and the (meth)acryloyl group in component (a1) react, or the photopolymerizable unsaturated groups in component (a4) react with each other. A three-dimensional network structure (crosslinked structure) is formed. When a polyfunctional polymerizable compound is used, the number of crosslinked structures formed by energy ray irradiation increases compared to when a compound containing only one photopolymerizable unsaturated group is used, so the buffer layer has a unique structure. It exhibits viscoelasticity, making it easier to adjust the breaking energy within the above range.
　なお、成分（ａ４）の定義と、先述した成分（ａ２）や成分（ａ３）の定義とは重複する部分があるが、重複部分は成分（ａ４）に含まれる。例えば、環形成原子数６～２０の脂環基又は複素環基を有し、（メタ）アクリロイル基を２つ以上有する化合物は、成分（ａ４）と成分（ａ２）の両方の定義に含まれるが、本発明において当該化合物は、成分（ａ４）に含まれるものとする。また、水酸基、エポキシ基、アミド基、アミノ基等の官能基を含有し、（メタ）アクリロイル基を２つ以上有する化合物は、成分（ａ４）と成分（ａ３）の両方の定義に含まれるが、本発明において当該化合物は、成分（ａ４）に含まれるものとする。 Note that there is some overlap between the definition of component (a4) and the definitions of component (a2) and component (a3) described above, but the overlap is included in component (a4). For example, a compound having an alicyclic group or a heterocyclic group having 6 to 20 ring atoms and having two or more (meth)acryloyl groups is included in the definition of both component (a4) and component (a2). However, in the present invention, the compound is included in component (a4). Furthermore, compounds containing functional groups such as hydroxyl groups, epoxy groups, amide groups, amino groups, etc., and having two or more (meth)acryloyl groups are included in the definition of both component (a4) and component (a3). In the present invention, the compound is included in component (a4).
　上記観点から、多官能重合性化合物中における光重合性不飽和基の数（官能基数）は、２～１０が好ましく、３～６がより好ましい。 From the above viewpoint, the number of photopolymerizable unsaturated groups (number of functional groups) in the polyfunctional polymerizable compound is preferably 2 to 10, more preferably 3 to 6.
　また、成分（ａ４）の重量平均分子量は、好ましくは３０～４０，０００、より好ましくは１００～１０，０００、更に好ましくは２００～１，０００である。 Furthermore, the weight average molecular weight of component (a4) is preferably 30 to 40,000, more preferably 100 to 10,000, and still more preferably 200 to 1,000.
　具体的な成分（ａ４）としては、例えば、ジエチレングリコールジ（メタ）アクリレート、エチレングリコールジ（メタ）アクリレート、テトラエチレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、ジビニルベンゼン、（メタ）アクリル酸ビニル、アジピン酸ジビニル、Ｎ，Ｎ'－メチレンビス（メタ）アクリルアミド等が挙げられる。
　これらの中でも、ジペンタエリスリトールヘキサ（メタ）アクリレートが好ましい。
　なお、成分（ａ４）は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 Specific examples of component (a4) include diethylene glycol di(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and 1,6-hexane. Diol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, divinylbenzene, vinyl (meth)acrylate , divinyl adipate, N,N'-methylenebis(meth)acrylamide, and the like.
Among these, dipentaerythritol hexa(meth)acrylate is preferred.
In addition, component (a4) may be used individually by 1 type, and may be used in combination of 2 or more types.
　緩衝層形成用組成物中の成分（ａ４）の含有量は、緩衝層形成用組成物の全量（１００質量％）に対して、好ましくは０質量％～４０質量％、より好ましくは０質量％～２０質量％、更に好ましくは０質量％～１５質量％である。 The content of component (a4) in the composition for forming a buffer layer is preferably 0% by mass to 40% by mass, more preferably 0% by mass, based on the total amount (100% by mass) of the composition for forming a buffer layer. ~20% by weight, more preferably 0% by weight ~ 15% by weight.
（成分（ａ１）～（ａ４）以外の重合性化合物（ａ５））
　緩衝層形成用組成物には、本発明の効果を損なわない範囲において、上記の成分（ａ１）～（ａ４）以外のその他成分として、重合性化合物（ａ５）（以下、「成分（ａ５）」ともいう）を含有してもよい。
　成分（ａ５）としては、例えば、炭素数１～２０のアルキル基を有するアルキル（メタ）アクリレート；スチレン、ヒドロキシエチルビニルエーテル、ヒドロキシブチルビニルエーテル、Ｎ－ビニルホルムアミド、Ｎ－ビニルピロリドン、Ｎ－ビニルカプロラクタム等のビニル化合物：等が挙げられる。
　なお、成分（ａ５）は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 (Polymerizable compound (a5) other than components (a1) to (a4))
In addition to the above-mentioned components (a1) to (a4), the composition for forming a buffer layer may contain a polymerizable compound (a5) (hereinafter referred to as "component (a5)"), as long as the effects of the present invention are not impaired. ) may also be included.
Component (a5) is, for example, an alkyl (meth)acrylate having an alkyl group having 1 to 20 carbon atoms; styrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N-vinylformamide, N-vinylpyrrolidone, N-vinylcaprolactam, etc. Vinyl compounds: etc.
In addition, component (a5) may be used alone or in combination of two or more.
　緩衝層形成用組成物中の成分（ａ５）の含有量は、好ましくは０質量％～２０質量％、より好ましくは０質量％～１０質量％、更に好ましくは０質量％～５質量％、より更に好ましくは０質量％～２質量％である。 The content of component (a5) in the composition for forming a buffer layer is preferably 0% by mass to 20% by mass, more preferably 0% to 10% by mass, even more preferably 0% to 5% by mass, and more preferably 0% to 10% by mass. More preferably, it is 0% to 2% by mass.
（光重合開始剤）
　緩衝層形成用組成物には、緩衝層を形成する際、光照射による重合時間を短縮させ、また、光照射量を低減させる観点から、さらに光重合開始剤を含有することが好ましい。 (Photopolymerization initiator)
The composition for forming a buffer layer preferably further contains a photopolymerization initiator from the viewpoint of shortening the polymerization time by light irradiation and reducing the amount of light irradiation when forming the buffer layer.
　光重合開始剤としては、例えば、ベンゾイン化合物、アセトフェノン化合物、アシルフォスフィノキサイド化合物、チタノセン化合物、チオキサントン化合物、パーオキサイド化合物、さらには、アミンやキノン等の光増感剤等が挙げられ、より具体的には、例えば、１－ヒドロキシシクロヘキシルフェニルケトン、２－ヒドロキシ－２－メチル－１－フェニル－プロパン－１－オン、ベンゾイン、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル、ベンジルフェニルサルファイド、テトラメチルチウラムモノサルファイド、アゾビスイソブチロニトリル、ジベンジル、ジアセチル、８－クロロアンスラキノン、ビス（２，４，６－トリメチルベンゾイル）フェニルフォスフィンオキシド等が挙げられる。
　これらの光重合開始剤は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。 Examples of photopolymerization initiators include benzoin compounds, acetophenone compounds, acylphosphinoxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and photosensitizers such as amines and quinones, and more. Specifically, for example, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzylphenyl sulfide, Examples include tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and the like.
These photopolymerization initiators may be used alone or in combination of two or more.
　緩衝層形成用組成物中の光重合開始剤の含有量は、エネルギー線重合性化合物の合計量１００質量部に対して、好ましくは０．０５質量部～１５質量部、より好ましくは０．１質量部～１０質量部、更に好ましくは０．３質量部～５質量部である。 The content of the photopolymerization initiator in the composition for forming a buffer layer is preferably 0.05 parts by mass to 15 parts by mass, more preferably 0.1 parts by mass, based on 100 parts by mass of the total amount of energy ray polymerizable compounds. The amount is from 10 parts by weight, more preferably from 0.3 parts to 5 parts by weight.
（その他の添加剤）
　緩衝層形成用組成物には、本発明の効果を損なわない範囲において、その他の添加剤を含有してもよい。その他の添加剤としては、例えば、帯電防止剤、酸化防止剤、軟化剤（可塑剤）、充填剤、防錆剤、顔料、染料等から選択される１種以上が挙げられる。これらの添加剤を配合する場合、緩衝層形成用組成物中の各添加剤の含有量は、エネルギー線重合性化合物の合計量１００質量部に対して、好ましくは０．０１質量部～６質量部、より好ましくは０．１質量部～３質量部である。 (Other additives)
The composition for forming a buffer layer may contain other additives to the extent that the effects of the present invention are not impaired. Examples of other additives include one or more selected from antistatic agents, antioxidants, softeners (plasticizers), fillers, rust preventives, pigments, dyes, and the like. When these additives are blended, the content of each additive in the composition for forming a buffer layer is preferably 0.01 parts by mass to 6 parts by mass based on 100 parts by mass of the total amount of energy ray polymerizable compounds. parts, more preferably 0.1 parts to 3 parts by weight.
（樹脂成分）
　緩衝層形成用組成物には、本発明の効果を損なわない範囲において、樹脂成分を含有してもよい。樹脂成分としては、例えば、ポリエン・チオール系樹脂や、ポリブテン、ポリブタジエン、ポリメチルペンテン等のポリオレフィン系樹脂、及びスチレン系共重合体等の熱可塑性樹脂等が挙げられる。
　緩衝層形成用組成物中のこれらの樹脂成分の含有量は、好ましくは０質量％～２０質量％、より好ましくは０質量％～１０質量％、更に好ましくは０質量％～５質量％、より更に好ましくは０質量％～２質量％である。 (resin component)
The composition for forming a buffer layer may contain a resin component within a range that does not impair the effects of the present invention. Examples of the resin component include polyene/thiol resins, polyolefin resins such as polybutene, polybutadiene, and polymethylpentene, and thermoplastic resins such as styrene copolymers.
The content of these resin components in the composition for forming a buffer layer is preferably 0% to 20% by mass, more preferably 0% to 10% by mass, even more preferably 0% to 5% by mass, and more preferably 0% to 10% by mass. More preferably, it is 0% to 2% by mass.
　エネルギー線重合性化合物を含む緩衝層形成用組成物から形成される緩衝層は、上記組成の緩衝層形成用組成物をエネルギー線照射により重合硬化して得られる。つまり、当該緩衝層は、緩衝層形成用組成物の硬化物である。
　したがって、当該緩衝層は、成分（ａ１）由来の重合単位を含む。また、当該緩衝層は、成分（ａ２）由来の重合単位及び成分（ａ３）由来の重合単位のうちの少なくとも１つを含有することが好ましい。さらに、成分（ａ４）由来の重合単位及び成分（ａ５）由来の重合単位のうちの少なくとも一方を含有していてもよい。
　緩衝層における各重合単位の含有割合は、通常、緩衝層形成用組成物を構成する各成分の比率（仕込み比）に一致する。例えば、緩衝層形成用組成物中の成分（ａ１）の含有量が緩衝層形成用組成物の全量（１００質量％）に対して１０質量％～７０質量％の場合、緩衝層は成分（ａ１）に由来する重合単位を１０質量％～７０質量％含有する。また、緩衝層形成用組成物中の成分（ａ２）の含有量が緩衝層形成用組成物の全量（１００質量％）に対して１０質量％～８０質量％の場合、緩衝層は成分（ａ２）に由来する重合単位を１０質量％～８０質量％含有する。成分（ａ３）～（ａ５）についても同様である。 A buffer layer formed from a composition for forming a buffer layer containing an energy ray polymerizable compound is obtained by polymerizing and curing the composition for forming a buffer layer having the above composition by irradiation with energy rays. That is, the buffer layer is a cured product of the composition for forming a buffer layer.
Therefore, the buffer layer contains polymerized units derived from component (a1). Moreover, it is preferable that the buffer layer contains at least one of a polymerized unit derived from component (a2) and a polymerized unit derived from component (a3). Furthermore, it may contain at least one of the polymerized units derived from component (a4) and the polymerized units derived from component (a5).
The content ratio of each polymerized unit in the buffer layer usually corresponds to the ratio (preparation ratio) of each component constituting the composition for forming a buffer layer. For example, when the content of component (a1) in the composition for forming a buffer layer is 10% by mass to 70% by mass with respect to the total amount (100% by mass) of the composition for forming a buffer layer, the buffer layer contains component (a1). ) Contains 10% to 70% by mass of polymerized units derived from. Further, when the content of component (a2) in the composition for forming a buffer layer is 10% by mass to 80% by mass with respect to the total amount (100% by mass) of the composition for forming a buffer layer, the buffer layer contains component (a2). ) contains 10% to 80% by mass of polymerized units derived from. The same applies to components (a3) to (a5).
　緩衝層の２３℃における破断エネルギーは、緩衝層がエネルギー線重合性化合物を含む緩衝層形成用組成物の硬化物である場合には、例えば上述のウレタン（メタ）アクリレート（ａ１）の重量平均分子量や緩衝層の厚みを調整し、またモノマー種を適宜選択することにより制御できる。 When the buffer layer is a cured product of a composition for forming a buffer layer containing an energy beam polymerizable compound, the breaking energy at 23° C. of the buffer layer is determined by, for example, the weight average molecular weight of the above-mentioned urethane (meth)acrylate (a1). It can be controlled by adjusting the thickness of the buffer layer and selecting the monomer species appropriately.
［基材］
　基材は、粘着テープの支持体としての機能を有する。
　基材としては、各種の樹脂フィルムが挙げられる。具体的には、低密度ポリエチレン（ＬＤＰＥ）、直鎖低密度ポリエチレン（ＬＬＤＰＥ）、高密度ポリエチレン（ＨＤＰＥ）等のポリエチレン、ポリプロピレン、ポリブテン、ポリブタジエン、ポリメチルペンテン、エチレン－ノルボルネン共重合体、ノルボルネン樹脂等のポリオレフィン；エチレン－酢酸ビニル共重合体、エチレン－（メタ）アクリル酸共重合体、エチレン－（メタ）アクリル酸エステル共重合体等のエチレン系共重合体；ポリ塩化ビニル、塩化ビニル共重合体等のポリ塩化ビニル；ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリブチレンテレフタレート、全芳香族ポリエステル等のポリエステル；ポリウレタン、ポリイミド、ポリアミド、ポリカーボネート、フッ素樹脂、ポリアセタール、変性ポリフェニレンオキシド、ポリフェニレンスルフィド、ポリスルホン、ポリエーテルケトン、アクリル系重合体などから選ばれる１種以上からなる樹脂フィルムが挙げられる。またこれらの架橋フィルム、アイオノマーフィルムのような変性フィルムも用いられる。基材は、これら樹脂から選ばれる１種又は２種以上の樹脂からなる樹脂フィルムの単層フィルムであってもよく、これらの樹脂フィルムを２種以上積層した積層フィルムであってもよい。 [Base material]
The base material functions as a support for the adhesive tape.
Examples of the base material include various resin films. Specifically, polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE), polypropylene, polybutene, polybutadiene, polymethylpentene, ethylene-norbornene copolymer, norbornene resin Polyolefins such as ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester copolymers, etc.; polyvinyl chloride, vinyl chloride copolymers Polyvinyl chloride such as coalescence; polyester such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, fully aromatic polyester; polyurethane, polyimide, polyamide, polycarbonate, fluororesin, polyacetal, modified polyphenylene oxide, polyphenylene sulfide, polysulfone, polyether Examples include resin films made of one or more selected from ketones, acrylic polymers, and the like. Modified films such as these crosslinked films and ionomer films can also be used. The base material may be a single-layer resin film made of one or more resins selected from these resins, or may be a laminated film in which two or more of these resin films are laminated.
　なお、基材は、緩衝層と比較して硬質であるため、刃による切断時に緩衝層と比較して切断面の荒れ等が発生し難いが、刃による切断性により優れる基材とする観点から、基材は、下記要件（γ）を満たすことが好ましい。
・要件（γ）：温度２３℃における破断ひずみ（ε１００）と温度２３℃における破断応力（ρ１００）との積が、６０ＭＰａ以上である。 In addition, since the base material is harder than the buffer layer, it is less likely that the cut surface will become rough when cut with a blade compared to the buffer layer, but from the viewpoint of making the base material more easily cut by the blade , the base material preferably satisfies the following requirement (γ).
- Requirement (γ): The product of the breaking strain (ε 100 ) at a temperature of 23°C and the breaking stress (ρ 100 ) at a temperature of 23°C is 60 MPa or more.
　また、基材は、２３℃における弾性率が、好ましくは２００ＭＰａ以上、より好ましくは５００ＭＰａ以上、更に好ましくは１，０００ＭＰａ以上である。また、好ましくは３０，０００ＭＰａ以下、より好ましくは１０，０００ＭＰａ以下、更に好ましくは６，０００ＭＰａ以下である。 Furthermore, the elastic modulus of the base material at 23° C. is preferably 200 MPa or more, more preferably 500 MPa or more, and still more preferably 1,000 MPa or more. Moreover, it is preferably 30,000 MPa or less, more preferably 10,000 MPa or less, and still more preferably 6,000 MPa or less.
　基材の厚さは特に限定されないが、１１０μｍ以下であることが好ましく、１５μｍ～１１０μｍであることがより好ましく、２０μｍ～１０５μｍであることが更に好ましい。基材の厚さを１１０μｍ以下とすることで、粘着テープの剥離力を制御しやすくなる。また、基材の厚さを１５μｍ以上とすることで、基材が粘着テープの支持体としての機能を果たしやすくなる。 The thickness of the base material is not particularly limited, but is preferably 110 μm or less, more preferably 15 μm to 110 μm, and even more preferably 20 μm to 105 μm. By setting the thickness of the base material to 110 μm or less, it becomes easier to control the peeling force of the adhesive tape. Further, by setting the thickness of the base material to 15 μm or more, the base material can easily function as a support for the adhesive tape.
　また、基材には、本発明の効果を損なわない範囲において、可塑剤、滑剤、赤外線吸収剤、紫外線吸収剤、フィラー、着色剤、帯電防止剤、酸化防止剤、触媒等を含有させてもよい。また、基材は、透明なものであっても、不透明なものであってもよく、所望により着色又は蒸着されていてもよい。
　また、基材の少なくとも一方の表面には、緩衝層及び粘着剤層の少なくとも一方との密着性を向上させるために、コロナ処理等の接着処理を施してもよい。また、基材は、上記した樹脂フィルムと、樹脂フィルムの少なくとも一方の表面に被膜された易接着層とを有しているものでもよい。 The base material may also contain plasticizers, lubricants, infrared absorbers, ultraviolet absorbers, fillers, colorants, antistatic agents, antioxidants, catalysts, etc., as long as they do not impair the effects of the present invention. good. Further, the base material may be transparent or opaque, and may be colored or vapor-deposited as desired.
Further, at least one surface of the base material may be subjected to adhesive treatment such as corona treatment in order to improve adhesion to at least one of the buffer layer and the adhesive layer. Further, the base material may include the resin film described above and an easily adhesive layer coated on at least one surface of the resin film.
　易接着層を形成する易接着層形成用組成物としては、特に限定されないが、例えば、ポリエステル系樹脂、ウレタン系樹脂、ポリエステルウレタン系樹脂、アクリル系樹脂等を含む組成物が挙げられる。易接着層形成用組成物には、必要に応じて、架橋剤、光重合開始剤、酸化防止剤、軟化剤（可塑剤）、充填剤、防錆剤、顔料、染料等を含有してもよい。
　易接着層の厚さとしては、好ましくは０．０１μｍ～１０μｍ、より好ましくは０．０３μｍ～５μｍである。なお、本願実施例における易接着層の厚さは、基材の厚さに対して小さいため、易接着層を有する樹脂フィルムの厚みと基材の厚みとは実質的に同一である。また、易接着層の材質は柔らかいため、弾性率に与える影響は小さく、基材の弾性率は、易接着層を有する場合でも、樹脂フィルムのヤング率と実質的に同一である。 The composition for forming an easily adhesive layer that forms the easily adhesive layer is not particularly limited, but examples thereof include compositions containing polyester resins, urethane resins, polyester urethane resins, acrylic resins, and the like. The composition for forming an easily adhesive layer may contain a crosslinking agent, a photopolymerization initiator, an antioxidant, a softener (plasticizer), a filler, a rust preventive, a pigment, a dye, etc., as necessary. good.
The thickness of the adhesive layer is preferably 0.01 μm to 10 μm, more preferably 0.03 μm to 5 μm. In addition, since the thickness of the easily bonding layer in the Examples of the present application is smaller than the thickness of the base material, the thickness of the resin film having the easily bonding layer and the thickness of the base material are substantially the same. In addition, since the material of the easily bonding layer is soft, its influence on the elastic modulus is small, and the elastic modulus of the base material is substantially the same as the Young's modulus of the resin film even when the base material has the easily bonding layer.
　例えば、要件（γ）で規定される、温度２３℃における破断ひずみ（ε１００）と温度２３℃における破断応力（ρ１００）との積、及び基材の弾性率は、樹脂組成の選択、可塑剤の添加、樹脂フィルム製造時の延伸条件などにより制御できる。具体的には、基材としてポリエチレンテレフタレートフィルムを用いる場合、共重合成分中のエチレン成分の含有割合が多くなると、基材の弾性率は低下する傾向がある。また、基材を構成する樹脂組成物に対して可塑剤の配合量が多くなると基材の弾性率は低下する傾向がある。 For example, the product of the breaking strain (ε 100 ) at a temperature of 23°C and the breaking stress (ρ 100 ) at a temperature of 23°C, which is defined by the requirement (γ), and the elastic modulus of the base material are determined by the selection of the resin composition, the plasticity It can be controlled by adding agents, stretching conditions during resin film production, etc. Specifically, when a polyethylene terephthalate film is used as a base material, the elastic modulus of the base material tends to decrease as the content of the ethylene component in the copolymer components increases. Furthermore, when the amount of plasticizer added to the resin composition constituting the base material increases, the elastic modulus of the base material tends to decrease.
［粘着剤層］
　粘着剤層は、常温において適度な感圧接着性を有する限り特に限定はされないが、２３℃におけるせん断貯蔵弾性率が０．０５ＭＰａ～０．５０ＭＰａであるものが好ましい。半導体ウエハの表面には、回路等が形成され通常凹凸がある。粘着剤層のせん断貯蔵弾性率が上記範囲内となることで、凹凸があるウエハ表面に粘着テープを貼付する際、ウエハ表面の凹凸と粘着剤層とを十分に接触させ、かつ粘着剤層の接着性を適切に発揮させることが可能になる。そのため、粘着テープの半導体ウエハへの固定を確実に行い、かつ裏面研削時にウエハ表面を適切に保護することが可能になる。これらの観点から、粘着剤層のせん断貯蔵弾性率は、０．１２～０．３５ＭＰａであることがより好ましい。なお、粘着剤層のせん断貯蔵弾性率とは、粘着剤層がエネルギー線硬化性粘着剤から形成される場合には、エネルギー線照射による硬化前のせん断貯蔵弾性率を意味する。 [Adhesive layer]
The adhesive layer is not particularly limited as long as it has appropriate pressure-sensitive adhesive properties at room temperature, but it is preferably one having a shear storage modulus of 0.05 MPa to 0.50 MPa at 23°C. The surface of a semiconductor wafer is usually uneven because circuits and the like are formed thereon. By setting the shear storage modulus of the adhesive layer within the above range, when applying an adhesive tape to an uneven wafer surface, the unevenness of the wafer surface and the adhesive layer can be brought into sufficient contact, and the adhesive layer can be It becomes possible to exhibit adhesiveness appropriately. Therefore, it is possible to reliably fix the adhesive tape to the semiconductor wafer and to appropriately protect the wafer surface during backside grinding. From these viewpoints, the shear storage modulus of the adhesive layer is more preferably 0.12 to 0.35 MPa. Note that the shear storage modulus of the adhesive layer means the shear storage modulus before curing by energy ray irradiation when the adhesive layer is formed from an energy ray curable adhesive.
　せん断貯蔵弾性率は以下の方法により測定できる。厚みが約０．５～１ｍｍの粘着剤層を直径７．９ｍｍの円形に打ち抜いたものを測定試料とする。レオメトリック社製の動的粘弾性測定装置ＡＲＥＳを用い、周波数１Ｈｚ、－３０℃から１５０℃の温度範囲を昇温速度３℃／分で温度変化させたときの測定試料の弾性率を測定する。測定温度２３℃での弾性率を、２３℃におけるせん断貯蔵弾性率とする。 The shear storage modulus can be measured by the following method. A measurement sample was prepared by punching out a circular shape with a diameter of 7.9 mm from an adhesive layer with a thickness of about 0.5 to 1 mm. Using the dynamic viscoelasticity measuring device ARES manufactured by Rheometric, measure the elastic modulus of the measurement sample when changing the temperature at a frequency of 1 Hz and a temperature range of -30°C to 150°C at a heating rate of 3°C/min. . The elastic modulus at the measurement temperature of 23°C is defined as the shear storage modulus at 23°C.
　粘着剤層の厚さは、１００μｍ未満であることが好ましく、５～８０μｍがより好ましく、１０～７０μｍがさらに好ましい。粘着剤層をこのように薄くすると、粘着テープの切断時におけるカットダストの発生が抑制され、裏面研削時に生じる半導体チップのクラックを一層防止しやすくなる。 The thickness of the adhesive layer is preferably less than 100 μm, more preferably 5 to 80 μm, and even more preferably 10 to 70 μm. When the adhesive layer is made thin in this manner, the generation of cut dust when cutting the adhesive tape is suppressed, and it becomes easier to prevent cracks in the semiconductor chip that occur during backside grinding.
　粘着剤層は、例えば、アクリル系粘着剤、ウレタン系粘着剤、ゴム系粘着剤、シリコーン系粘着剤等から形成されるが、アクリル系粘着剤が好ましい。
　また、粘着剤層は、エネルギー線硬化性粘着剤から形成されることが好ましい。粘着剤層は、エネルギー線硬化性粘着剤から形成されることで、エネルギー線照射による硬化前には、２３℃におけるせん断貯蔵弾性率を上記範囲に設定しつつ、硬化後においては剥離力を１０００ｍＮ／５０ｍｍ以下に容易に設定することが可能になる。 The adhesive layer is formed from, for example, an acrylic adhesive, a urethane adhesive, a rubber adhesive, a silicone adhesive, etc., and an acrylic adhesive is preferred.
Moreover, it is preferable that the adhesive layer is formed from an energy ray-curable adhesive. The adhesive layer is formed from an energy ray curable adhesive, so that the shear storage modulus at 23°C is set within the above range before curing by energy ray irradiation, and the peeling force is set to 1000 mN after curing. /50mm or less.
　以下、粘着剤の具体例について詳述するが、これらは非限定的例示であり、本発明における粘着剤層はこれらに限定的に解釈されるべきではない。
　エネルギー線硬化性粘着剤としては、例えば、非エネルギー線硬化性の粘着性樹脂（「粘着性樹脂Ｉ」ともいう）に加え、粘着性樹脂以外のエネルギー線硬化性化合物を含むエネルギー線硬化性粘着剤組成物（以下、「Ｘ型の粘着剤組成物」ともいう）が使用可能である。また、エネルギー線硬化性粘着剤として、非エネルギー線硬化性の粘着性樹脂の側鎖に不飽和基を導入したエネルギー線硬化性の粘着性樹脂（以下、「粘着性樹脂ＩＩ」ともいう）を主成分として含み、粘着性樹脂以外のエネルギー線硬化性化合物を含まない粘着剤組成物（以下、「Ｙ型の粘着剤組成物」ともいう）も使用してもよい。 Hereinafter, specific examples of the adhesive will be described in detail, but these are just non-limiting examples, and the adhesive layer in the present invention should not be interpreted as being limited to these.
Examples of the energy ray curable adhesive include, in addition to a non-energy ray curable adhesive resin (also referred to as "adhesive resin I"), an energy ray curable adhesive containing an energy ray curable compound other than the adhesive resin. (hereinafter also referred to as "X-type adhesive composition") can be used. In addition, as an energy ray curable adhesive, an energy ray curable adhesive resin (hereinafter also referred to as "Adhesive Resin II"), which has an unsaturated group introduced into the side chain of a non-energy ray curable adhesive resin, is used. A pressure-sensitive adhesive composition (hereinafter also referred to as "Y-type pressure-sensitive adhesive composition") which contains the energy ray-curable compound as a main component and does not contain any energy ray-curable compounds other than the adhesive resin may also be used.
　さらに、エネルギー線硬化性粘着剤としては、Ｘ型とＹ型の併用型、すなわち、エネルギー線硬化性の粘着性樹脂ＩＩに加え、粘着性樹脂以外のエネルギー線硬化性化合物も含むエネルギー線硬化性粘着剤組成物（以下、「ＸＹ型の粘着剤組成物」ともいう）を使用してもよい。
　これらの中では、ＸＹ型の粘着剤組成物を使用することが好ましい。ＸＹ型のものを使用することで、硬化前においては十分な粘着特性を有する一方で、硬化後においては、半導体ウエハに対する剥離力を十分に低くすることが可能である。 Furthermore, the energy ray curable adhesive may be a combination of X type and Y type, that is, an energy ray curable adhesive containing an energy ray curable compound other than the adhesive resin in addition to the energy ray curable adhesive resin II. A pressure-sensitive adhesive composition (hereinafter also referred to as "XY-type pressure-sensitive adhesive composition") may be used.
Among these, it is preferable to use an XY type adhesive composition. By using an XY type material, it is possible to have sufficient adhesive properties before curing, and to sufficiently reduce the peeling force against the semiconductor wafer after curing.
　ただし、粘着剤としては、エネルギー線を照射しても硬化しない非エネルギー線硬化性の粘着剤組成物から形成してもよい。非エネルギー線硬化性の粘着剤組成物は、少なくとも非エネルギー線硬化性の粘着性樹脂Ｉを含有する一方、上記したエネルギー線硬化性の粘着性樹脂ＩＩ及びエネルギー線硬化性化合物を含有しないものである。 However, the adhesive may be formed from a non-energy ray-curable adhesive composition that does not harden even when irradiated with energy rays. The non-energy ray curable adhesive composition contains at least the non-energy ray curable adhesive resin I, but does not contain the energy ray curable adhesive resin II and the energy ray curable compound described above. be.
　なお、以下の説明において「粘着性樹脂」は、上記した粘着性樹脂Ｉ及び粘着性樹脂ＩＩの一方又は両方を指す用語として使用する。具体的な粘着性樹脂としては、例えば、アクリル系樹脂、ウレタン系樹脂、ゴム系樹脂、シリコーン系樹脂等が挙げられるが、アクリル系樹脂が好ましい。
　以下、粘着性樹脂として、アクリル系樹脂が使用されるアクリル系粘着剤についてより詳細に説明する。 In the following description, the term "adhesive resin" is used to refer to one or both of the above-described adhesive resin I and adhesive resin II. Specific adhesive resins include, for example, acrylic resins, urethane resins, rubber resins, silicone resins, and acrylic resins are preferred.
Hereinafter, the acrylic adhesive in which an acrylic resin is used as the adhesive resin will be described in more detail.
＜アクリル系樹脂＞
　アクリル系樹脂には、アクリル系重合体（ｂ）が使用される。アクリル系重合体（ｂ）は、少なくともアルキル（メタ）アクリレートを含むモノマーを重合して得たものであり、アルキル（メタ）アクリレート由来の構成単位を含む。アルキル（メタ）アクリレートとしては、アルキル基の炭素数が１～２０のものが挙げられ、アルキル基は直鎖であってもよいし、分岐であってもよい。アルキル（メタ）アクリレートの具体例としては、メチル（メタ）アクリレート、エチル（メタ）アクリレート、イソプロピル（メタ）アクリレート、ｎ－プロピル（メタ）アクリレート、ｎ－ブチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ｎ－オクチル（メタ）アクリレート、イソオクチル（メタ）アクリレート、ノニル（メタ）アクリレート、デシル（メタ）アクリレート、ウンデシル（メタ）アクリレート、ドデシル（メタ）アクリレート等が挙げられる。アルキル（メタ）アクリレートは、単独で又は２種以上組み合わせて用いてもよい。 <Acrylic resin>
An acrylic polymer (b) is used as the acrylic resin. The acrylic polymer (b) is obtained by polymerizing a monomer containing at least an alkyl (meth)acrylate, and contains structural units derived from the alkyl (meth)acrylate. Examples of the alkyl (meth)acrylate include those in which the alkyl group has 1 to 20 carbon atoms, and the alkyl group may be linear or branched. Specific examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. ) acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, and the like. Alkyl (meth)acrylates may be used alone or in combination of two or more.
　また、アクリル系重合体（ｂ）は、粘着剤層の粘着力を向上させる観点から、アルキル基の炭素数が４以上であるアルキル（メタ）アクリレート由来の構成単位を含むことが好ましい。該アルキル（メタ）アクリレートの炭素数としては、好ましくは４～１２、さらに好ましくは４～６である。また、アルキル基の炭素数が４以上であるアルキル（メタ）アクリレートは、アルキルアクリレートであることが好ましい。 Furthermore, from the viewpoint of improving the adhesive strength of the adhesive layer, the acrylic polymer (b) preferably contains a structural unit derived from an alkyl (meth)acrylate in which the alkyl group has 4 or more carbon atoms. The alkyl (meth)acrylate preferably has 4 to 12 carbon atoms, more preferably 4 to 6 carbon atoms. Further, the alkyl (meth)acrylate in which the alkyl group has 4 or more carbon atoms is preferably an alkyl acrylate.
　アクリル系重合体（ｂ）において、アルキル基の炭素数が４以上であるアルキル（メタ）アクリレートは、アクリル系重合体（ｂ）を構成するモノマー全量（以下単に“モノマー全量”ともいう）に対して、好ましくは４０質量％～９８質量％、より好ましくは４５質量％～９５質量％、更に好ましくは５０質量％～９０質量％である。 In the acrylic polymer (b), the alkyl (meth)acrylate whose alkyl group has 4 or more carbon atoms is based on the total amount of monomers (hereinafter also simply referred to as "total monomer amount") constituting the acrylic polymer (b). The content is preferably 40% to 98% by weight, more preferably 45% to 95% by weight, and still more preferably 50% to 90% by weight.
　アクリル系重合体（ｂ）は、アルキル基の炭素数が４以上であるアルキル（メタ）アクレート由来の構成単位に加えて、粘着剤層の弾性率や粘着特性を調整するために、アルキル基の炭素数が１～３であるアルキル（メタ）アクリレート由来の構成単位を含む共重合体であることが好ましい。なお、該アルキル（メタ）アクリレートは、炭素数１又は２のアルキル（メタ）アクリレートであることが好ましく、メチル（メタ）アクリレートがより好ましく、メチルメタクリレートが更に好ましい。アクリル系重合体（ｂ）において、アルキル基の炭素数が１～３であるアルキル（メタ）アクリレートは、モノマー全量に対して、好ましくは１質量％～３０質量％、より好ましくは３質量％～２６質量％、更に好ましくは６質量％～２２質量％である。 In addition to the structural unit derived from alkyl (meth)acrylate in which the alkyl group has 4 or more carbon atoms, the acrylic polymer (b) contains alkyl groups in order to adjust the elastic modulus and adhesive properties of the adhesive layer. A copolymer containing a structural unit derived from an alkyl (meth)acrylate having 1 to 3 carbon atoms is preferable. Note that the alkyl (meth)acrylate is preferably an alkyl (meth)acrylate having 1 or 2 carbon atoms, more preferably methyl (meth)acrylate, and even more preferably methyl methacrylate. In the acrylic polymer (b), the alkyl (meth)acrylate whose alkyl group has 1 to 3 carbon atoms is preferably 1% by mass to 30% by mass, more preferably 3% by mass to 3% by mass, based on the total amount of monomers. The amount is 26% by weight, more preferably 6% to 22% by weight.
　アクリル系重合体（ｂ）は、上記したアルキル（メタ）アクリレート由来の構成単位に加えて、官能基含有モノマー由来の構成単位を有することが好ましい。官能基含有モノマーの官能基としては、水酸基、カルボキシ基、アミノ基、エポキシ基等が挙げられる。官能基含有モノマーは、後述の架橋剤と反応し、架橋起点となったり、不飽和基含有化合物と反応して、アクリル系重合体（ｂ）の側鎖に不飽和基を導入させたりすることが可能である。 It is preferable that the acrylic polymer (b) has a structural unit derived from a functional group-containing monomer in addition to the structural unit derived from the alkyl (meth)acrylate described above. Examples of the functional group of the functional group-containing monomer include a hydroxyl group, a carboxy group, an amino group, and an epoxy group. The functional group-containing monomer reacts with a crosslinking agent described below to become a crosslinking starting point, or reacts with an unsaturated group-containing compound to introduce an unsaturated group into the side chain of the acrylic polymer (b). is possible.
　官能基含有モノマーとしては、水酸基含有モノマー、カルボキシ基含有モノマー、アミノ基含有モノマー、エポキシ基含有モノマー等が挙げられる。これらのモノマーは、単独で又は２種以上組み合わせて用いてもよい。これらの中でも、水酸基含有モノマー、カルボキシ基含有モノマーが好ましく、水酸基含有モノマーがより好ましい。 Examples of functional group-containing monomers include hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, epoxy group-containing monomers, and the like. These monomers may be used alone or in combination of two or more. Among these, hydroxyl group-containing monomers and carboxyl group-containing monomers are preferred, and hydroxyl group-containing monomers are more preferred.
　水酸基含有モノマーとしては、例えば、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、３－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート等のヒドロキシアルキル（メタ）アクリレート；ビニルアルコール、アリルアルコール等の不飽和アルコール等が挙げられる。 Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 3-hydroxybutyl (meth)acrylate. ) acrylate, hydroxyalkyl (meth)acrylates such as 4-hydroxybutyl (meth)acrylate; and unsaturated alcohols such as vinyl alcohol and allyl alcohol.
　カルボキシ基含有モノマーとしては、例えば、（メタ）アクリル酸、クロトン酸等のエチレン性不飽和モノカルボン酸；フマル酸、イタコン酸、マレイン酸、シトラコン酸等のエチレン性不飽和ジカルボン酸及びその無水物、２－カルボキシエチルメタクリレート等が挙げられる。 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.
　官能基含有モノマーは、アクリル系重合体（ｂ）を構成するモノマー全量に対して、好ましくは１質量％～３５質量％、より好ましくは３質量％～３２質量％、更に好ましくは６質量％～３０質量％である。
　また、アクリル系重合体（ｂ）は、上記以外にも、スチレン、α－メチルスチレン、ビニルトルエン、蟻酸ビニル、酢酸ビニル、アクリロニトリル、アクリルアミド等の上記のアクリル系モノマーと共重合可能なモノマー由来の構成単位を含んでもよい。 The functional group-containing monomer is preferably 1% by mass to 35% by mass, more preferably 3% to 32% by mass, still more preferably 6% by mass to the total amount of monomers constituting the acrylic polymer (b). It is 30% by mass.
In addition to the above, the acrylic polymer (b) may also be derived from monomers copolymerizable with the above acrylic monomers, such as styrene, α-methylstyrene, vinyltoluene, vinyl formate, vinyl acetate, acrylonitrile, and acrylamide. It may also include structural units.
　上記アクリル系重合体（ｂ）は、非エネルギー線硬化性の粘着性樹脂Ｉ（アクリル系樹脂）として使用することができる。また、エネルギー線硬化性のアクリル系樹脂としては、上記アクリル系重合体（ｂ）の官能基に、光重合性不飽和基を有する化合物（不飽和基含有化合物ともいう）を反応させたものが挙げられる。 The above acrylic polymer (b) can be used as a non-energy ray-curable adhesive resin I (acrylic resin). In addition, as an energy ray-curable acrylic resin, one in which a compound having a photopolymerizable unsaturated group (also referred to as an unsaturated group-containing compound) is reacted with the functional group of the acrylic polymer (b) is used. Can be mentioned.
　不飽和基含有化合物は、アクリル系重合体（ｂ）の官能基と結合可能な置換基、及び光重合性不飽和基の双方を有する化合物である。光重合性不飽和基としては、（メタ）アクリロイル基、ビニル基、アリル基、ビニルベンジル基等が挙げられ、（メタ）アクリロイル基が好ましい。
　また、不飽和基含有化合物が有する、官能基と結合可能な置換基としては、イソシアネート基やグリシジル基等が挙げられる。したがって、不飽和基含有化合物としては、例えば、（メタ）アクリロイルオキシエチルイソシアネート、（メタ）アクリロイルイソシアネート、グリシジル（メタ）アクリレート等が挙げられる。 The unsaturated group-containing compound is a compound that has both a substituent that can bond to the functional group of the acrylic polymer (b) and a photopolymerizable unsaturated group. Examples of the photopolymerizable unsaturated group include a (meth)acryloyl group, a vinyl group, an allyl group, a vinylbenzyl group, and a (meth)acryloyl group is preferred.
Further, examples of the substituent which the unsaturated group-containing compound has and which can bond to a functional group include an isocyanate group and a glycidyl group. Therefore, examples of the unsaturated group-containing compound include (meth)acryloyloxyethyl isocyanate, (meth)acryloyl isocyanate, glycidyl (meth)acrylate, and the like.
　また、不飽和基含有化合物は、アクリル系重合体（ｂ）の官能基の一部に反応することが好ましく、具体的には、アクリル系重合体（ｂ）が有する官能基の５０～９８モル％に、不飽和基含有化合物を反応させることが好ましく、５５～９３モル％反応させることがより好ましい。このように、エネルギー線硬化性アクリル系樹脂において、官能基の一部が不飽和基含有化合物と反応せずに残存することで、架橋剤によって架橋されやすくなる。
　なお、アクリル系樹脂の重量平均分子量（Ｍｗ）は、好ましくは３０万～１６０万、より好ましくは４０万～１４０万、さらに好ましくは５０万～１２０万である。 Further, it is preferable that the unsaturated group-containing compound reacts with a part of the functional groups of the acrylic polymer (b), and specifically, 50 to 98 moles of the functional groups of the acrylic polymer (b). % of the unsaturated group-containing compound, more preferably 55 to 93 mol %. In this way, in the energy beam-curable acrylic resin, some of the functional groups remain without reacting with the unsaturated group-containing compound, making it easier to be crosslinked by the crosslinking agent.
The weight average molecular weight (Mw) of the acrylic resin is preferably 300,000 to 1,600,000, more preferably 400,000 to 1,400,000, and even more preferably 500,000 to 1,200,000.
＜エネルギー線硬化性化合物＞
　Ｘ型又はＸＹ型の粘着剤組成物に含有されるエネルギー線硬化性化合物としては、分子内に不飽和基を有し、エネルギー線照射により重合硬化可能なモノマー又はオリゴマーが好ましい。
　このようなエネルギー線硬化性化合物としては、例えば、トリメチロールプロパントリ（メタ）アクリレート、ペンタエリスリトール（メタ）アクリレート、ペンタエリスリトールテトラ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、１，４－ブチレングリコールジ（メタ）アクリレート、１，６－へキサンジオール（メタ）アクリレート等の多価（メタ）アクリレートモノマー、ウレタン（メタ）アクリレート、ポリエステル（メタ）アクリレート，ポリエーテル（メタ）アクリレート、エポキシ（メタ）アクリレート等のオリゴマーが挙げられる。 <Energy ray curable compound>
The energy ray-curable compound contained in the X-type or XY-type pressure-sensitive adhesive composition is preferably a monomer or oligomer that has an unsaturated group in its molecule and can be polymerized and cured by energy ray irradiation.
Examples of such energy ray-curable compounds include trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4- Polyvalent (meth)acrylate monomers such as butylene glycol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, epoxy ( Examples include oligomers such as meth)acrylate.
　これらの中でも、比較的分子量が高く、粘着剤層のせん断貯蔵弾性率を低下させにくい観点から、ウレタン（メタ）アクリレートオリゴマーが好ましい。
　エネルギー線硬化性化合物の分子量（オリゴマーの場合は重量平均分子量）は、好ましくは１００～１２，０００、より好ましくは２００～１０，０００、更に好ましくは４００～８，０００、より更に好ましくは６００～６，０００である。 Among these, urethane (meth)acrylate oligomers are preferred because they have a relatively high molecular weight and are difficult to reduce the shear storage modulus of the adhesive layer.
The molecular weight (weight average molecular weight in the case of oligomers) of the energy ray curable compound is preferably 100 to 12,000, more preferably 200 to 10,000, still more preferably 400 to 8,000, and even more preferably 600 to 10,000. 6,000.
　Ｘ型の粘着剤組成物におけるエネルギー線硬化性化合物の含有量は、粘着性樹脂１００質量部に対して、好ましくは４０質量部～２００質量部、より好ましくは５０質量部～１５０質量部、さらに好ましくは６０質量部～９０質量部である。
　一方で、ＸＹ型の粘着剤組成物におけるエネルギー線硬化性化合物の含有量は、粘着性樹脂１００質量部に対して、好ましくは１質量部～３０質量部、より好ましくは２質量部～２０質量部、さらに好ましくは３質量部～１５質量部である。ＸＹ型の粘着剤組成物では、粘着性樹脂が、エネルギー線硬化性であるため、エネルギー線硬化性化合物の含有量が少なくても、エネルギー線照射後、十分に剥離力を低下させることが可能である。 The content of the energy ray-curable compound in the X-type adhesive composition is preferably 40 parts by mass to 200 parts by mass, more preferably 50 parts by mass to 150 parts by mass, and more preferably 50 parts by mass to 150 parts by mass, based on 100 parts by mass of adhesive resin. Preferably it is 60 parts by mass to 90 parts by mass.
On the other hand, the content of the energy ray-curable compound in the XY-type adhesive composition is preferably 1 part by mass to 30 parts by mass, more preferably 2 parts by mass to 20 parts by mass, based on 100 parts by mass of the adhesive resin. parts, more preferably 3 parts to 15 parts by weight. In the XY type adhesive composition, the adhesive resin is energy ray curable, so even if the content of the energy ray curable compound is small, it is possible to sufficiently reduce the peeling force after energy ray irradiation. It is.
＜架橋剤＞
　粘着剤組成物は、さらに架橋剤を含有することが好ましい。架橋剤は、例えば粘着性樹脂が有する官能基含有モノマー由来の官能基に反応して、粘着性樹脂同士を架橋するものである。架橋剤としては、例えば、トリレンジイソシアネート、ヘキサメチレンジイソシアネート等、及びそれらのアダクト体等のイソシアネート系架橋剤；エチレングリコールグリシジルエーテル等のエポキシ系架橋剤；ヘキサ［１－（２－メチル）－アジリジニル］トリフォスファトリアジン等のアジリジン系架橋剤；アルミニウムキレート等のキレート系架橋剤；等が挙げられる。これらの架橋剤は、単独で又は２種以上を組み合わせて用いてもよい。 <Crosslinking agent>
It is preferable that the adhesive composition further contains a crosslinking agent. The crosslinking agent crosslinks the adhesive resins by reacting with, for example, a functional group derived from a functional group-containing monomer that the adhesive resin has. Examples of the crosslinking agent include isocyanate crosslinking agents such as tolylene diisocyanate, hexamethylene diisocyanate, and adducts thereof; epoxy crosslinking agents such as ethylene glycol glycidyl ether; hexa[1-(2-methyl)-aziridinyl ] Aziridine crosslinking agents such as triphosphatriazine; Chelate crosslinking agents such as aluminum chelate; and the like. These crosslinking agents may be used alone or in combination of two or more.
　これらの中でも、凝集力を高めて粘着力を向上させる観点、及び入手し易さ等の観点から、イソシアネート系架橋剤が好ましい。
　架橋剤の配合量は、架橋反応を促進させる観点から、粘着性樹脂１００質量部に対して、好ましくは０．０１質量部～１０質量部、より好ましくは０．０３質量部～７質量部、さらに好ましくは０．０５質量部～４質量部である。 Among these, isocyanate-based crosslinking agents are preferred from the viewpoint of increasing cohesive force to improve adhesive strength and from the viewpoint of ease of availability.
From the viewpoint of promoting the crosslinking reaction, the amount of the crosslinking agent is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.03 parts by mass to 7 parts by mass, based on 100 parts by mass of the adhesive resin. More preferably, the amount is 0.05 parts by mass to 4 parts by mass.
＜光重合開始剤＞
　また、粘着剤組成物がエネルギー線硬化性である場合には、粘着剤組成物は、さらに光重合開始剤を含有することが好ましい。光重合開始剤を含有することで、紫外線等の比較的低エネルギーのエネルギー線でも、粘着剤組成物の硬化反応を十分に進行させることができる。 <Photopolymerization initiator>
Moreover, when the adhesive composition is energy ray curable, it is preferable that the adhesive composition further contains a photopolymerization initiator. By containing a photopolymerization initiator, the curing reaction of the pressure-sensitive adhesive composition can sufficiently proceed even with relatively low-energy energy rays such as ultraviolet rays.
　光重合開始剤としては、例えば、ベンゾイン化合物、アセトフェノン化合物、アシルフォスフィノキサイド化合物、チタノセン化合物、チオキサントン化合物、パーオキサイド化合物、さらには、アミンやキノン等の光増感剤等が挙げられ、より具体的には、例えば、１－ヒドロキシシクロへキシルフェニルケトン、２－ヒドロキシ－２－メチル－１－フェニル－プロパン－１－オン、ベンゾイン、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインイソプロピルエーテル、ベンジルフェニルサルファイド、テトラメチルチウラムモノサルファイド、アゾビスイソブチロルニトリル、ジベンジル、ジアセチル、８－クロールアンスラキノン、ビス（２，４，６－トリメチルベンゾイル）フェニルフォスフィンオキシド等が挙げられる。 Examples of photopolymerization initiators include benzoin compounds, acetophenone compounds, acylphosphinoxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and photosensitizers such as amines and quinones, and more. Specifically, for example, 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzylphenyl Examples include sulfide, tetramethylthiuram monosulfide, azobisisobutyrolonitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and the like.
　これらの光重合開始剤は、１種を単独で用いてもよく、２種以上を組み合わせて用いてもよい。
　光重合開始剤の配合量は、粘着性樹脂１００質量部に対して、好ましくは０．０１質量部～１０質量部、より好ましくは０．０３質量部～５質量部、更に好ましくは０．０５質量部～５質量部である。 These photopolymerization initiators may be used alone or in combination of two or more.
The amount of the photopolymerization initiator is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.03 parts to 5 parts by mass, and even more preferably 0.05 parts by mass, based on 100 parts by mass of the adhesive resin. Parts by mass to 5 parts by mass.
＜その他の添加剤＞
　粘着性組成物は、本発明の効果を損なわない範囲において、その他の添加剤を含有してもよい。その他の添加剤としては、例えば、帯電防止剤、酸化防止剤、軟化剤（可塑剤）、充填剤、防錆剤、顔料、染料等が挙げられる。これらの添加剤を配合する場合、添加剤の配合量は、粘着性樹脂１００質量部に対して、好ましくは０．０１質量部～６質量部である。 <Other additives>
The adhesive composition may contain other additives to the extent that the effects of the present invention are not impaired. Examples of other additives include antistatic agents, antioxidants, softeners (plasticizers), fillers, rust preventives, pigments, and dyes. When blending these additives, the blending amount of the additives is preferably 0.01 parts by mass to 6 parts by mass based on 100 parts by mass of the adhesive resin.
　また、粘着性組成物は、基材、緩衝層や剥離シートへの塗布性を向上させる観点から、さらに有機溶媒で希釈して、粘着性組成物の溶液の形態としてもよい。
　有機溶媒としては、例えば、メチルエチルケトン、アセトン、酢酸エチル、テトラヒドロフラン、ジオキサン、シクロヘキサン、ｎ－ヘキサン、トルエン、キシレン、ｎ－プロパノール、イソプロパノール等が挙げられる。
　なお、これらの有機溶媒は、粘着性樹脂の合成時に使用された有機溶媒をそのまま用いてもよいし、該粘着剤組成物の溶液を均一に塗布できるように、合成時に使用された有機溶媒以外の１種以上の有機溶媒を加えてもよい。 Further, the adhesive composition may be further diluted with an organic solvent to form a solution of the adhesive composition from the viewpoint of improving the applicability to a substrate, a buffer layer, or a release sheet.
Examples of the organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, and isopropanol.
As these organic solvents, the organic solvents used during the synthesis of the adhesive resin may be used as they are, or organic solvents other than those used during the synthesis may be used in order to uniformly apply the solution of the adhesive composition. One or more organic solvents may be added.
［剥離シート］
　粘着テープの表面には、剥離シートが貼付されていてもよい。剥離シートは、具体的には、粘着テープの粘着剤層の表面に貼付される。剥離シートは、粘着剤層表面に貼付されることで輸送時、保管時に粘着剤層を保護する。剥離シートは、剥離可能に粘着テープに貼付されており、粘着テープが使用される前（すなわち、ウエハ貼付前）には、粘着テープから剥離されて取り除かれる。
　剥離シートは、少なくとも一方の面が剥離処理をされた剥離シートが用いられ、具体的には、剥離シート用基材の表面上に剥離剤を塗布したもの等が挙げられる。 [Release sheet]
A release sheet may be attached to the surface of the adhesive tape. Specifically, the release sheet is attached to the surface of the adhesive layer of the adhesive tape. The release sheet protects the adhesive layer during transportation and storage by being attached to the surface of the adhesive layer. The release sheet is releasably attached to the adhesive tape, and is peeled off and removed from the adhesive tape before the adhesive tape is used (ie, before the wafer is attached).
As the release sheet, a release sheet whose at least one side has been subjected to a release treatment is used, and specifically, a release sheet having a release agent coated on the surface of a base material for the release sheet can be mentioned.
　剥離シート用基材としては、樹脂フィルムが好ましく、当該樹脂フィルムを構成する樹脂としては、例えば、ポリエチレンテレフタレート樹脂、ポリブチレンテレフタレート樹脂、ポリエチレンナフタレート樹脂等のポリエステル樹脂フィルム、ポリプロピレン樹脂、ポリエチレン樹脂等のポリオレフィン樹脂等が挙げられる。剥離剤としては、例えば、シリコーン系樹脂、オレフィン系樹脂、イソプレン系樹脂、ブタジエン系樹脂等のゴム系エラストマー、長鎖アルキル系樹脂、アルキド系樹脂、フッ素系樹脂等が挙げられる。
　剥離シートの厚さは、特に制限ないが、好ましくは１０μｍ～２００μｍ、より好ましくは２０μｍ～１５０μｍである。 As the base material for the release sheet, a resin film is preferable, and examples of the resin constituting the resin film include polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, and polyethylene naphthalate resin, polypropylene resin, polyethylene resin, etc. Polyolefin resins and the like can be mentioned. Examples of the release agent include rubber elastomers such as silicone resins, olefin resins, isoprene resins, and butadiene resins, long-chain alkyl resins, alkyd resins, and fluororesins.
The thickness of the release sheet is not particularly limited, but is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm.
［半導体加工用粘着テープの製造方法］
　本発明の半導体加工用粘着テープの製造方法としては、特に制限はなく、公知の方法により製造することができる。
　例えば、緩衝層と、基材と、粘着剤層とがこの順で積層された積層構造を有する粘着テープの製造方法は以下のとおりである。 [Method for manufacturing adhesive tape for semiconductor processing]
The method of manufacturing the adhesive tape for semiconductor processing of the present invention is not particularly limited, and can be manufactured by any known method.
For example, a method for manufacturing an adhesive tape having a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order is as follows.
　緩衝層がエネルギー線重合性化合物を含む緩衝層形成用組成物から形成される場合には、剥離シート上に緩衝層形成用組成物を塗工、硬化して設けた緩衝層と、基材とを貼り合わせ、剥離シートを除去することで、緩衝層と基材との積層体が得られる。 When the buffer layer is formed from a buffer layer forming composition containing an energy beam polymerizable compound, the buffer layer formed by coating and curing the buffer layer forming composition on a release sheet, and the base material. By laminating them together and removing the release sheet, a laminate of the buffer layer and the base material can be obtained.
　そして、剥離シート上に設けた粘着剤層を、積層体の基材側に貼り合わせ、粘着剤層の表面に剥離シートが貼付された粘着テープを製造することができる。粘着剤層の表面に貼付される剥離シートは、粘着テープの使用前に適宜剥離して除去すればよい。 Then, the adhesive layer provided on the release sheet is bonded to the base material side of the laminate to produce an adhesive tape with the release sheet attached to the surface of the adhesive layer. The release sheet attached to the surface of the adhesive layer may be peeled off and removed as appropriate before use of the adhesive tape.
　剥離シート上に緩衝層を形成する方法としては、剥離シート上に緩衝層形成用組成物を、公知の塗布方法にて、直接塗布して塗布膜を形成し、この塗布膜にエネルギー線を照射することで、緩衝層を形成することができる。また、基材の片面に、緩衝層形成用組成物を直接塗布して、加熱乾燥あるいは塗布膜にエネルギー線を照射することで、緩衝層を形成してもよい。 A method for forming a buffer layer on a release sheet is to directly apply a composition for forming a buffer layer onto a release sheet using a known coating method to form a coating film, and then irradiate this coating film with energy rays. By doing so, a buffer layer can be formed. Alternatively, the buffer layer may be formed by directly coating the composition for forming a buffer layer on one side of the base material and drying it by heating or by irradiating the coated film with energy rays.
　緩衝層形成用組成物の塗布方法としては、例えば、スピンコート法、スプレーコート法、バーコート法、ナイフコート法、ロールコート法、ブレードコート法、ダイコート法、グラビアコート法等が挙げられる。また、塗布性を向上させるために、緩衝層形成用組成物に対して有機溶媒を配合し、溶液の形態として、剥離シート上に塗布してもよい。 Examples of methods for applying the composition for forming a buffer layer include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating. Further, in order to improve the coating properties, an organic solvent may be added to the composition for forming a buffer layer, and the composition may be applied in the form of a solution onto a release sheet.
　緩衝層形成用組成物がエネルギー線重合性化合物を含む場合、緩衝層形成用組成物の塗布膜に対して、エネルギー線を照射することで硬化させ、緩衝層を形成することが好ましい。緩衝層の硬化は、一度の硬化処理で行ってもよいし、複数回に分けて行ってもよい。例えば、剥離シート上の塗布膜を完全に硬化させて緩衝層を形成した後に基材に貼り合わせてもよく、当該塗布膜を完全に硬化させずに半硬化の状態の緩衝層形成膜を形成し、当該緩衝層形成膜を基材に貼り合わせた後、再度エネルギー線を照射して完全に硬化させて緩衝層を形成してもよい。当該硬化処理で照射するエネルギー線としては、紫外線が好ましい。なお、硬化する際は、緩衝層形成用組成物の塗布膜が暴露された状態でもよいが、剥離シートや基材で塗布膜が覆われ、塗布膜が暴露されない状態でエネルギー線を照射して硬化することが好ましい。 When the buffer layer forming composition contains an energy ray polymerizable compound, it is preferable to cure the coating film of the buffer layer forming composition by irradiating it with energy rays to form a buffer layer. The curing of the buffer layer may be performed in one curing process, or may be performed in multiple steps. For example, the coating film on the release sheet may be completely cured to form a buffer layer and then bonded to the base material, or the buffer layer forming film in a semi-cured state may be formed without completely curing the coating film. However, after bonding the buffer layer forming film to the base material, the buffer layer may be formed by irradiating energy rays again to completely cure the film. As the energy rays irradiated in the curing process, ultraviolet rays are preferable. When curing, the coating film of the composition for forming a buffer layer may be exposed, but it is possible to cover the coating film with a release sheet or base material and irradiate it with energy rays without exposing the coating film. Preferably, it is cured.
　剥離シート上に粘着剤層を形成する方法としては、剥離シート上に粘着剤（粘着剤組成物）を、公知の塗布方法にて、直接塗布して塗布膜を加熱乾燥することで、粘着剤層を形成することができる。 The method for forming the adhesive layer on the release sheet is to directly apply the adhesive (adhesive composition) onto the release sheet using a known coating method and heat and dry the coated film. layers can be formed.
　また、基材の片面に、粘着剤（粘着剤組成物）を直接塗布して、粘着剤層を形成してもよい。粘着剤の塗布方法としては、緩衝層の製造法で示した、スプレーコート法、バーコート法、ナイフコート法、ロールコート法、ブレードコート法、ダイコート法、グラビアコート法等が挙げられる。 Alternatively, an adhesive layer may be formed by directly applying an adhesive (adhesive composition) to one side of the base material. Examples of methods for applying the adhesive include spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating as shown in the buffer layer manufacturing method.
［半導体加工用粘着テープの使用方法］
　本発明の半導体加工用粘着テープは、半導体ウエハの裏面研削を行う際に、半導体ウエハの表面（回路形成面）に貼付し、半導体ウエハの外周に沿って切断して、使用される。
　本発明の一態様において、本発明の半導体加工用粘着テープは、半導体ウエハを裏面研削する際に（詳細には、半導体ウエハの裏面研削工程を含む半導体チップの製造時に）、半導体ウエハの表面（回路形成面）に貼付し、半導体ウエハの外周に沿って切断して、使用される。
　半導体ウエハの裏面研削工程を含む半導体チップの製造方法としては、半導体ウエハを裏面研削した後にダイシングして個片化する方法、上述したＤＢＧ又はＤＢＧの変形法が挙げられる。
　本発明の半導体加工用粘着テープは、刃による切断性に優れる。そのため、当該半導体加工用粘着テープを半導体ウエハの外周に沿って切断する際に、カットダストが発生し難く、半導体ウエハの裏面研削工程を含む半導体チップの製造時において、当該カットダストに起因する半導体チップの欠けや破損の発生が抑制される。 [How to use adhesive tape for semiconductor processing]
The adhesive tape for semiconductor processing of the present invention is used by applying it to the front surface (circuit forming surface) of a semiconductor wafer and cutting it along the outer periphery of the semiconductor wafer when grinding the back surface of the semiconductor wafer.
In one aspect of the present invention, the adhesive tape for semiconductor processing of the present invention is used when back-grinding a semiconductor wafer (specifically, during semiconductor chip manufacturing including a back-grinding process of the semiconductor wafer). It is used by attaching it to the circuit forming surface) and cutting it along the outer periphery of the semiconductor wafer.
Examples of a semiconductor chip manufacturing method that includes a step of back grinding a semiconductor wafer include a method in which a semiconductor wafer is back ground and then diced into pieces, and the above-mentioned DBG or a modification of DBG.
The adhesive tape for semiconductor processing of the present invention has excellent cuttability with a blade. Therefore, when cutting the adhesive tape for semiconductor processing along the outer periphery of a semiconductor wafer, cut dust is less likely to be generated, and during semiconductor chip manufacturing including the back grinding process of the semiconductor wafer, the cut dust caused by the semiconductor wafer is less likely to be generated. The occurrence of chipping and damage to the chip is suppressed.
　したがって、本発明の一態様では、下記（１）又は（２）の使用方法が提供される。
（１）本発明の半導体加工用粘着テープの使用方法であって、半導体ウエハを裏面研削する際に、前記半導体加工用粘着テープを半導体ウエハの表面に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する、使用方法。
（２）上記（１）の使用方法において、半導体ウエハとして、表面側に溝が形成された半導体ウエハ又は内部に改質領域が形成された半導体ウエハを用いる、使用方法。 Therefore, in one aspect of the present invention, the method of use (1) or (2) below is provided.
(1) A method of using the adhesive tape for semiconductor processing of the present invention, which comprises: attaching the adhesive tape for semiconductor processing to the surface of the semiconductor wafer when back-grinding the semiconductor wafer; A usage method for cutting along the outer circumference of a semiconductor wafer.
(2) In the method of (1) above, the method uses, as the semiconductor wafer, a semiconductor wafer with grooves formed on the surface side or a semiconductor wafer with a modified region formed inside.
［半導体装置の製造方法］
　本発明の半導体装置の製造方法は、半導体ウエハの裏面研削工程を含む半導体チップの製造方法であり、本発明の半導体加工用粘着テープを半導体ウエハの表面（回路形成面）に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する工程（Ｓ１）を含む。
　本発明の半導体加工用粘着テープは、刃による切断性に優れる。そのため、上記工程（Ｓ１）において、カットダストが発生し難く、当該カットダストに起因する半導体チップのクラックの発生が抑制される。 [Method for manufacturing semiconductor device]
The method of manufacturing a semiconductor device of the present invention is a method of manufacturing a semiconductor chip including a step of grinding the back side of a semiconductor wafer, in which the adhesive tape for semiconductor processing of the present invention is affixed to the front surface (circuit formation surface) of the semiconductor wafer, and the semiconductor The method includes a step (S1) of cutting the processing adhesive tape along the outer periphery of the semiconductor wafer.
The adhesive tape for semiconductor processing of the present invention has excellent cuttability with a blade. Therefore, in the step (S1), cut dust is hardly generated, and the occurrence of cracks in the semiconductor chip due to the cut dust is suppressed.
　本発明の半導体装置の製造方法の工程概略図を図２に示す。
　本発明の半導体装置の製造方法は、大まかには、半導体加工用粘着テープを半導体ウエハの表面（回路形成面）に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する工程（Ｓ１）と、前記半導体ウエハを裏面側から研削する工程（Ｓ２）とを含む。
　前記半導体ウエハは、工程（Ｓ２）の後、ダイシングして個片化してもよい（態様１）。
　また、前記半導体ウエハは、工程（Ｓ２）において個片化してもよい（態様２）。
　具体的には、前記半導体ウエハとして、表面側に溝が形成された半導体ウエハを用い、工程（Ｓ２）において、前記半導体ウエハを、前記溝を起点として複数のチップに個片化させてもよい。
　また、前記半導体ウエハとして、内部に改質領域が形成された半導体ウエハを用いるか、又は、前記工程（Ｓ１）の後に前記半導体ウエハの内部に改質領域を形成し、工程（Ｓ２）において、前記半導体ウエハを、改質領域を起点として複数のチップに個片化させてもよい。 FIG. 2 shows a process schematic diagram of the method for manufacturing a semiconductor device of the present invention.
Roughly speaking, the method for manufacturing a semiconductor device of the present invention includes applying an adhesive tape for semiconductor processing to the surface (circuit forming surface) of a semiconductor wafer, and cutting the adhesive tape for semiconductor processing along the outer periphery of the semiconductor wafer. The method includes a step (S1) and a step (S2) of grinding the semiconductor wafer from the back side.
After the step (S2), the semiconductor wafer may be diced into individual pieces (aspect 1).
Further, the semiconductor wafer may be separated into pieces in the step (S2) (aspect 2).
Specifically, the semiconductor wafer may be a semiconductor wafer with grooves formed on its surface side, and in the step (S2), the semiconductor wafer may be singulated into a plurality of chips using the grooves as starting points. .
Further, as the semiconductor wafer, a semiconductor wafer in which a modified region is formed is used, or a modified region is formed inside the semiconductor wafer after the step (S1), and in the step (S2), The semiconductor wafer may be singulated into a plurality of chips starting from the modified region.
　以下に、各工程の詳細について説明する。 The details of each step will be explained below.
＜工程（Ｓ１）＞
　工程（Ｓ１）では、本発明の半導体加工用粘着テープを半導体ウエハの表面（回路形成面）に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する。
　半導体加工用粘着テープは、半導体ウエハの表面（回路形成面）およびその外周に拡がる外周テーブルを覆うように貼り付けられる。そして、半導体加工用粘着テープは、半導体ウエハの外周に沿って、カッター等の刃により緩衝層側の面から入刃されて切断される。切断速度は、通常１０～３００ｍｍ／ｓである。切断時の刃の温度は室温でもよく、また、刃を加熱して切断してもよい。 <Step (S1)>
In step (S1), the adhesive tape for semiconductor processing of the present invention is applied to the surface (circuit formation surface) of the semiconductor wafer, and the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer.
The adhesive tape for semiconductor processing is applied so as to cover the surface (circuit forming surface) of the semiconductor wafer and the outer peripheral table extending around the outer periphery of the semiconductor wafer. Then, the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer by inserting the blade of a cutter or the like from the surface on the buffer layer side. The cutting speed is usually 10 to 300 mm/s. The temperature of the blade during cutting may be at room temperature, or the blade may be heated for cutting.
　本製造方法で用いられる半導体ウエハとしては、例えば、シリコンウエハ、ガリウム砒素ウエハ、炭化ケイ素ウエハ、タンタル酸リチウムウエハ、ニオブ酸リチウムウエハ、窒化ガリウムウエハ、インジウム燐ウエハ、及びガラスウエハ等が挙げられる。
　半導体ウエハの裏面研削前の厚さは特に限定されないが、通常は５００μｍ～１０００μｍ程度である。
　また、半導体ウエハの表面への回路形成は、エッチング法及びリフトオフ法等の従来汎用されている方法を含む様々な方法により行うことができる。 Examples of semiconductor wafers used in this manufacturing method include silicon wafers, gallium arsenide wafers, silicon carbide wafers, lithium tantalate wafers, lithium niobate wafers, gallium nitride wafers, indium phosphorous wafers, and glass wafers.
The thickness of the semiconductor wafer before back grinding is not particularly limited, but is usually about 500 μm to 1000 μm.
Further, circuit formation on the surface of a semiconductor wafer can be performed by various methods including conventionally widely used methods such as etching method and lift-off method.
　本製造方法においてＤＢＧを採用する場合、工程（Ｓ１）において半導体加工用粘着テープを貼付する半導体ウエハは、表面に溝が形成された半導体ウエハである。
　表面に溝が形成された半導体ウエハは、従来公知のウエハダイシング装置等を用いてレーザーダイシングやブレードダイシング等により作製することができる。当該溝は、半導体ウエハを個片化して半導体チップにする際の分割起点となる。 When DBG is employed in this manufacturing method, the semiconductor wafer to which the adhesive tape for semiconductor processing is attached in step (S1) is a semiconductor wafer with grooves formed on its surface.
A semiconductor wafer having grooves formed on its surface can be manufactured by laser dicing, blade dicing, or the like using a conventionally known wafer dicing device or the like. The grooves serve as starting points for dividing the semiconductor wafer into individual semiconductor chips.
　本製造方法においてＤＢＧの変形法を採用する場合、工程（Ｓ１）において半導体加工用粘着テープを貼付する半導体ウエハは、内部に改質領域が形成された半導体ウエハである。但し、当該改質領域は、工程（Ｓ１）の後に形成してもよい。
　改質領域は、半導体ウエハにおいて、脆質化された部分であり、半導体ウエハを個片化して半導体チップにする際の分割起点となる。
　内部に改質領域が形成された半導体ウエハは、半導体ウエハの内部に焦点を合わせたレーザーの照射やプラズマの照射により作製される。レーザー又はプラズマの照射は、半導体ウエハの表面側から行っても、裏面側から行ってもよい。 When the DBG modification method is adopted in this manufacturing method, the semiconductor wafer to which the adhesive tape for semiconductor processing is attached in step (S1) is a semiconductor wafer in which a modified region is formed. However, the modified region may be formed after step (S1).
The modified region is a portion of the semiconductor wafer that has been made brittle, and serves as a starting point for dividing the semiconductor wafer into individual chips.
A semiconductor wafer with a modified region formed therein is produced by laser irradiation or plasma irradiation focused on the inside of the semiconductor wafer. Laser or plasma irradiation may be performed from the front side or the back side of the semiconductor wafer.
　工程（Ｓ１）が完了した、半導体加工用粘着テープ付きの半導体ウエハは、チャックテーブル上に載置され、チャックテーブルに吸着されて保持される。その際、半導体加工用粘着テープ付きの半導体ウエハは、チャックテーブルと半導体加工用粘着テープの緩衝層とが直接接するようにチャックテーブル上に載置される。つまり、半導体ウエハは、表面側がチャックテーブル側に配置される。 The semiconductor wafer with the adhesive tape for semiconductor processing on which the step (S1) has been completed is placed on the chuck table, and is held by suction on the chuck table. At this time, the semiconductor wafer with the adhesive tape for semiconductor processing attached thereto is placed on the chuck table so that the chuck table and the buffer layer of the adhesive tape for semiconductor processing are in direct contact with each other. In other words, the front side of the semiconductor wafer is placed on the chuck table side.
＜態様１＞
　態様１では、工程（Ｓ２）を実施した後、工程（Ｓ３）を実施して、半導体ウエハを個片化する。
　態様１では、表面に溝が形成された半導体ウエハや内部に改質領域が形成された半導体ウエハのような分割起点を有する半導体ウエハではなく、このような分割起点を有しない半導体ウエハが用いられる。
（工程（Ｓ２））
　工程（２）では、チャックテーブル上の半導体ウエハの裏面を研削する。
　裏面研削後の半導体ウエハの厚さは、特に限定されないが、好ましくは５μｍ～１００μｍ程度、より好ましくは１０μｍ～４５μｍである。 <Aspect 1>
In embodiment 1, after the step (S2) is performed, the step (S3) is performed to separate the semiconductor wafer into pieces.
In embodiment 1, a semiconductor wafer that does not have such a division starting point is used instead of a semiconductor wafer that has a dividing starting point such as a semiconductor wafer with grooves formed on the surface or a semiconductor wafer with a modified region formed inside. .
(Step (S2))
In step (2), the back surface of the semiconductor wafer on the chuck table is ground.
The thickness of the semiconductor wafer after back grinding is not particularly limited, but is preferably about 5 μm to 100 μm, more preferably 10 μm to 45 μm.
（工程（Ｓ３））
　工程（Ｓ３）では、工程（Ｓ２）を実施した半導体ウエハをダイシングして個片化する。ダイシングは、ブレードダイシングやレーザーダイシング等、従来公知の方法を採用して適宜実施することができる。 (Step (S3))
In step (S3), the semiconductor wafer subjected to step (S2) is diced into individual pieces. Dicing can be appropriately performed by employing conventionally known methods such as blade dicing and laser dicing.
　個片化された半導体チップの形状は、方形でもよいし、矩形等の細長形状となっていてもよい。また、個片化された半導体チップの厚さは特に限定されないが、好ましくは５μｍ～１００μｍ程度、より好ましくは１０μｍ～４５μｍである。
　個片化された半導体チップの面積は特に限定されないが、好ましくは６００ｍｍ２未満、より好ましくは４００ｍｍ２未満、さらに好ましくは３００ｍｍ２未満である。 The shape of the diced semiconductor chip may be square, or may be an elongated shape such as a rectangle. Furthermore, the thickness of the diced semiconductor chip is not particularly limited, but is preferably about 5 μm to 100 μm, more preferably 10 μm to 45 μm.
The area of the diced semiconductor chip is not particularly limited, but is preferably less than 600 mm 2 , more preferably less than 400 mm 2 , and still more preferably less than 300 mm 2 .
＜態様２＞
　態様２では、工程（Ｓ２）において、半導体ウエハを裏面研削するとともに、半導体ウエハを個片化する。
（工程（Ｓ２））
　工程（Ｓ２）では、チャックテーブル上の半導体ウエハの裏面を研削して、半導体ウエハを複数の半導体チップに個片化する。 <Aspect 2>
In the second embodiment, in the step (S2), the back surface of the semiconductor wafer is ground and the semiconductor wafer is cut into pieces.
(Step (S2))
In step (S2), the back surface of the semiconductor wafer on the chuck table is ground to separate the semiconductor wafer into a plurality of semiconductor chips.
　ここで、態様２における第一実施形態では、表面に溝が形成された半導体ウエハが用いられる。この場合には、少なくとも溝の底部に至る位置まで半導体ウエハの裏面研削を行う。この裏面研削により、溝は、半導体ウエハを貫通する切り込みとなり、半導体ウエハは切り込みにより分割されて、個々の半導体チップに個片化されることになる。 Here, in the first embodiment of aspect 2, a semiconductor wafer with grooves formed on its surface is used. In this case, the back surface of the semiconductor wafer is ground to at least the bottom of the groove. By this back grinding, the grooves become cuts that penetrate the semiconductor wafer, and the semiconductor wafer is divided by the cuts to be singulated into individual semiconductor chips.
　また、態様２における第二実施形態では、内部に改質領域が形成された半導体ウエハが用いられる。又は、前記工程（Ｓ１）の後に前記半導体ウエハの内部に改質領域を形成してもよい。態様２における第二実施形態では、改質領域に至るまで裏面研削を行ってもよいが、厳密に改質領域まで至らなくてもよい。すなわち、改質領域を起点として半導体ウエハが破壊されて半導体チップに個片化されるように、改質領域に近接する位置まで裏面研削を行えばよい。 Furthermore, in the second embodiment of aspect 2, a semiconductor wafer in which a modified region is formed is used. Alternatively, a modified region may be formed inside the semiconductor wafer after the step (S1). In the second embodiment of aspect 2, back grinding may be performed until reaching the modified region, but it is not necessary to strictly reach the modified region. That is, back grinding may be performed to a position close to the modified region so that the semiconductor wafer is broken starting from the modified region and separated into semiconductor chips.
　また、得られた複数の半導体チップは、後述するピックアップテープを貼付してからピックアップテープを延伸し、チップ間の隙間を広げるようにしてもよい。 Alternatively, a pickup tape, which will be described later, may be attached to the obtained plurality of semiconductor chips, and then the pickup tape may be stretched to widen the gaps between the chips.
　また、裏面研削の終了後、チップのピックアップに先立ち、ドライポリッシュを行ってもよい。 Furthermore, after finishing the back grinding and before picking up the chips, dry polishing may be performed.
　個片化された半導体チップの形状、厚さ、面積は、態様１で説明したとおりである。
　なお、内部に改質領域が形成された半導体ウエハを用いる場合、個片化された半導体チップの厚さを５０μｍ以下、より好ましくは１０μｍ～４５μｍとすることが容易になる。 The shape, thickness, and area of the diced semiconductor chips are as described in the first embodiment.
Note that when using a semiconductor wafer in which a modified region is formed, it is easy to make the thickness of the diced semiconductor chips 50 μm or less, more preferably 10 μm to 45 μm.
　本発明の半導体加工用粘着テープは、刃による切断性に優れる。そのため、上記工程（Ｓ１）において、カットダストが発生し難い。したがって、態様１の工程（Ｓ２）及び態様２の工程（Ｓ２）において、薄型化・小型化された半導体チップを製造する場合であっても、当該カットダストに起因する半導体チップの欠けや破損の発生が抑制される。 The adhesive tape for semiconductor processing of the present invention has excellent cuttability with a blade. Therefore, cut dust is less likely to be generated in the step (S1). Therefore, in the step (S2) of Aspect 1 and the step (S2) of Aspect 2, even when manufacturing thinner and smaller semiconductor chips, chipping and damage of semiconductor chips caused by the cut dust may occur. Occurrence is suppressed.
＜半導体加工用粘着テープの剥離＞
　工程（Ｓ２）の後、個片化された半導体ウエハ（すなわち、複数の半導体チップ）から、半導体加工用粘着テープを剥離する。
　本工程は、例えば、以下の方法により行う。
　半導体加工用粘着テープの粘着剤層が、エネルギー線硬化性粘着剤から形成される場合には、エネルギー線を照射して粘着剤層を硬化する。次いで、個片化された半導体ウエハの裏面側に、ピックアップテープを貼付し、ピックアップが可能なように位置及び方向合わせを行う。その際、ウエハの外周側に配置したリングフレームもピックアープテープに貼り合わせ、ピックアップテープの外周縁部をリングフレームに固定する。ピックアップテープには、ウエハとリングフレームを同時に貼り合わせてもよいし、別々のタイミングで貼り合わせてもよい。次いで、ピックアップテープ上に保持された複数の半導体チップから粘着テープを剥離する。 <Peeling of adhesive tape for semiconductor processing>
After the step (S2), the adhesive tape for semiconductor processing is peeled off from the diced semiconductor wafer (ie, a plurality of semiconductor chips).
This step is performed, for example, by the following method.
When the adhesive layer of the adhesive tape for semiconductor processing is formed from an energy ray-curable adhesive, the adhesive layer is cured by irradiating with energy rays. Next, a pick-up tape is attached to the back side of the diced semiconductor wafer, and the position and orientation are adjusted so that it can be picked up. At this time, the ring frame placed on the outer peripheral side of the wafer is also attached to the pick-up tape, and the outer peripheral edge of the pick-up tape is fixed to the ring frame. The wafer and ring frame may be attached to the pickup tape at the same time or at different times. Next, the adhesive tape is peeled off from the plurality of semiconductor chips held on the pickup tape.
　その後、ピックアップテープ上にある複数の半導体チップをピックアップし基板等の上に固定化して、半導体装置を製造する。なお、ピックアップテープは、特に限定されないが、例えば、基材と、基材の少なくとも一方の面に設けられた粘着剤層を備える粘着テープによって構成される。 Thereafter, a plurality of semiconductor chips on the pickup tape are picked up and fixed onto a substrate or the like to manufacture a semiconductor device. Note that the pickup tape is not particularly limited, but is configured, for example, by an adhesive tape including a base material and an adhesive layer provided on at least one surface of the base material.
　また、ピックアップテープの代わりに、接着テープを用いることもできる。接着テープとは、フィルム状接着剤と剥離シートとの積層体、ダイシングテープとフィルム状接着剤との積層体や、ダイシングテープとダイボンディングテープの両方の機能を有する接着剤層と剥離シートとからなるダイシング・ダイボンディングテープ等が挙げられる。また、ピックアップテープを貼付する前に、個片化された半導体ウエハの裏面側にフィルム状接着剤を貼り合わせてもよい。フィルム状接着剤を用いる場合、フィルム状接着剤はウエハと同形状としてもよい。 Also, adhesive tape can be used instead of the pickup tape. Adhesive tape can be a laminate of a film adhesive and a release sheet, a laminate of a dicing tape and a film adhesive, or an adhesive layer and release sheet that have the functions of both a dicing tape and a die bonding tape. Examples include dicing and die bonding tapes. Further, before applying the pickup tape, a film adhesive may be applied to the back side of the semiconductor wafer that has been separated into pieces. When using a film adhesive, the film adhesive may have the same shape as the wafer.
　接着テープを用いる場合やピックアップテープを貼付する前に個片化された半導体ウエハの裏面側にフィルム状接着剤を貼り合わせる場合には、接着テープやピックアップテープ上にある複数の半導体チップは、半導体チップと同形状に分割された接着剤層と共にピックアップされる。そして、半導体チップは接着剤層を介して基板等の上に固定化され、半導体装置が製造される。接着剤層の分割は、レーザーやエキスパンドによって行われる。 When using an adhesive tape or when bonding a film adhesive to the back side of a semiconductor wafer that has been cut into pieces before pasting a pick-up tape, multiple semiconductor chips on the adhesive tape or pick-up tape are The chip is picked up together with the adhesive layer, which is divided into parts having the same shape as the chip. Then, the semiconductor chip is fixed onto a substrate or the like via an adhesive layer, and a semiconductor device is manufactured. The adhesive layer is divided by laser or expansion.
　以上、本発明の半導体装置の製造方法について説明したが、本発明の半導体加工用粘着テープは、半導体ウエハを個片化した際に、カーフ幅の小さく、より薄化された半導体チップ群が得られるＤＢＧの変形法に特に好ましく使用できる。 The method for manufacturing a semiconductor device according to the present invention has been described above, and the adhesive tape for semiconductor processing according to the present invention provides a group of thinner semiconductor chips with a smaller kerf width when a semiconductor wafer is diced. It can be particularly preferably used in a DBG modification method.
　なお、本発明の半導体加工用粘着テープは、ガラス、セラミック等の加工時にも被加工物を一時的に保持するために使用することも勿論可能である。また、各種の再剥離粘着テープとしても使用できる。 Note that the adhesive tape for semiconductor processing of the present invention can of course be used to temporarily hold a workpiece during processing of glass, ceramics, etc. It can also be used as various removable adhesive tapes.
　本発明について、以下の実施例により具体的に説明するが、本発明は以下の実施例に限定されるものではない。 The present invention will be specifically explained with reference to the following examples, but the present invention is not limited to the following examples.
［製造例Ａ１～Ａ４、比較製造例Ｂ１～Ｂ３、参考例Ｃ１～Ｃ２］
＜製造例Ａ１：緩衝層Ａ－１の形成＞
　ウレタンアクリレートオリゴマー（ＣＮ８８８８、アルケマ株式会社製）７５質量部と、４－ｔｅｒｔ－ブチルシクロヘキサノールアクリレート２５質量部との合計１００質量部に対して、光重合開始剤（ＢＡＳＦ社製「イルガキュア１１７３」、２－ヒドロキシ－２－メチル－１－フェニルプロパン－１－オン）を２．０質量部配合し、緩衝層用組成物を得た。
　得られた緩衝層用組成物を、ナイフコート法により、基材であるＰＥＴフィルム（東洋紡株式会社製「コスモシャインＡ４３００」、両面易接着層付ＰＥＴフィルム、厚み：５０μｍ）の上に厚みが２８μｍになるように塗工して緩衝層用組成物層を形成し、塗工直後に緩衝層用組成物層に高圧水銀ランプを用いて、照度１６０ｍＷ／ｃｍ２、照射量５００ｍＪ／ｃｍ２の条件で紫外線照射を行うことにより緩衝層用組成物層を硬化させ、基材であるＰＥＴフィルムの一方の面に厚さ２８μｍの緩衝層Ａ－１を形成し、緩衝層Ａ－１付きＰＥＴ基材を作製した。 [Production Examples A1 to A4, Comparative Production Examples B1 to B3, Reference Examples C1 to C2]
<Manufacture example A1: Formation of buffer layer A-1>
A photopolymerization initiator ("Irgacure 1173" manufactured by BASF Corporation), 2.0 parts by mass of 2-hydroxy-2-methyl-1-phenylpropan-1-one) was added to obtain a buffer layer composition.
The obtained composition for a buffer layer was applied to a thickness of 28 μm on a PET film (“Cosmoshine A4300” manufactured by Toyobo Co., Ltd., PET film with easy adhesive layer on both sides, thickness: 50 μm) as a base material by a knife coating method. Immediately after coating, a high-pressure mercury lamp was applied to the buffer layer composition layer under the conditions of an illuminance of 160 mW/cm 2 and an irradiation amount of 500 mJ/cm 2 . The composition layer for the buffer layer is cured by UV irradiation to form a buffer layer A-1 with a thickness of 28 μm on one side of the PET film that is the base material, and the PET base material with the buffer layer A-1 is cured. was created.
＜製造例Ａ２：緩衝層Ａ－２の形成＞
　緩衝層用組成物の配合を、以下のように変更し、製造例Ａ１と同様の方法で、基材であるＰＥＴフィルム上に厚さ２８μｍの緩衝層Ａ－２を形成した。
・ウレタンアクリレートオリゴマー（ＣＮ８８８８、アルケマ株式会社製）：５０質量部
・４－ｔｅｒｔ－ブチルシクロヘキサノールアクリレート：４０質量部
・ジペンタエリスリトールヘキサアクリレート：１０質量部
・光重合開始剤（ＢＡＳＦ社製「イルガキュア１１７３」）：２．０質量部 <Manufacture example A2: Formation of buffer layer A-2>
A buffer layer A-2 having a thickness of 28 μm was formed on a PET film as a base material in the same manner as in Production Example A1 by changing the formulation of the buffer layer composition as follows.
・Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ・4-tert-butylcyclohexanol acrylate: 40 parts by mass ・Dipentaerythritol hexaacrylate: 10 parts by mass ・Photopolymerization initiator (manufactured by BASF "Irgacure") 1173''): 2.0 parts by mass
＜製造例Ａ３：緩衝層Ａ－３の形成＞
　緩衝層用組成物の配合を、以下のように変更し、製造例Ａ１と同様の方法で、基材であるＰＥＴフィルム上に厚さ２８μｍの緩衝層Ａ－３を形成した。
・ウレタンアクリレートオリゴマー（ＣＮ８８８８、アルケマ株式会社製）：５０質量部
・４－ｔｅｒｔ－ブチルシクロヘキサノールアクリレート：４５質量部
・ジペンタエリスリトールヘキサアクリレート：５質量部
・光重合開始剤（ＢＡＳＦ社製「イルガキュア１１７３」）：２．０質量部 <Manufacture example A3: Formation of buffer layer A-3>
A buffer layer A-3 having a thickness of 28 μm was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
・Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ・4-tert-butylcyclohexanol acrylate: 45 parts by mass ・Dipentaerythritol hexaacrylate: 5 parts by mass ・Photopolymerization initiator (manufactured by BASF "Irgacure") 1173''): 2.0 parts by mass
＜製造例Ａ４：緩衝層Ａ－４の形成＞
　緩衝層用組成物の配合を、以下のように変更し、製造例Ａ１と同様の方法で、基材であるＰＥＴフィルム上に厚さ２８μｍの緩衝層Ａ－４を形成した。
・ウレタンアクリレートオリゴマー（ＣＮ８８８８、アルケマ株式会社製）：５０質量部
・イソボルニルアクリレート：４５質量部
・ジペンタエリスリトールヘキサアクリレート：５質量部
・光重合開始剤（ＢＡＳＦ社製「イルガキュア１１７３」）：２．０質量部 <Production Example A4: Formation of buffer layer A-4>
A buffer layer A-4 having a thickness of 28 μm was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
・Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ・Isobornyl acrylate: 45 parts by mass ・Dipentaerythritol hexaacrylate: 5 parts by mass ・Photopolymerization initiator (“Irgacure 1173” manufactured by BASF): 2.0 parts by mass
＜比較製造例Ｂ１：緩衝層Ｂ－１の製造の形成＞
　緩衝層用組成物の配合を、以下のように変更し、製造例Ａ１と同様の方法で、基材であるＰＥＴフィルム上に厚さ２８μｍの緩衝層Ｂ－１を形成した。
・ウレタンアクリレートオリゴマー（ＣＮ８８８８、アルケマ株式会社製）：５０質量部
・３，３，５－トリメチルシクロヘキサノールアクリレート：５０質量部
・光重合開始剤（ＢＡＳＦ社製「イルガキュア１１７３」）：２．０質量部 <Comparative manufacturing example B1: Formation of manufacturing of buffer layer B-1>
A buffer layer B-1 having a thickness of 28 μm was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
・Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ・3,3,5-trimethylcyclohexanol acrylate: 50 parts by mass ・Photopolymerization initiator (“Irgacure 1173” manufactured by BASF): 2.0 parts by mass Department
＜比較製造例Ｂ２：緩衝層Ｂ－２の形成＞
　緩衝層用組成物の配合を、以下のように変更し、製造例Ａ１と同様の方法で、基材であるＰＥＴフィルム上に厚さ２８μｍの緩衝層Ｂ－２を形成した。
・ウレタンアクリレートオリゴマー（ＣＮ８８８８、アルケマ株式会社製）：５０質量部
・イソボルニルアクリレート：４５質量部
・トリシクロデカンジメタノールジアクリレート：５質量部
・光重合開始剤（ＢＡＳＦ社製「イルガキュア１１７３」）：２．０質量部 <Comparative production example B2: Formation of buffer layer B-2>
A buffer layer B-2 having a thickness of 28 μm was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
・Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ・Isobornyl acrylate: 45 parts by mass ・Tricyclodecane dimethanol diacrylate: 5 parts by mass ・Photopolymerization initiator ("Irgacure 1173" manufactured by BASF Corporation) ): 2.0 parts by mass
＜比較製造例Ｂ３：緩衝層Ｂ－３の形成＞
　緩衝層用組成物の配合を、以下のように変更し、製造例Ａ１と同様の方法で、基材であるＰＥＴフィルム上に厚さ２８μｍの緩衝層Ｂ－３を形成した。
・ウレタンアクリレートオリゴマー（ＣＮ８８８８、アルケマ株式会社製）：５０質量部
・環状トリメチロールプロパンフォルマルアクリレート：５０質量部
・光重合開始剤（ＢＡＳＦ社製「イルガキュア１１７３」）：２．０質量部 <Comparative manufacturing example B3: Formation of buffer layer B-3>
A buffer layer B-3 having a thickness of 28 μm was formed on a PET film as a base material in the same manner as in Production Example A1, with the formulation of the buffer layer composition changed as follows.
・Urethane acrylate oligomer (CN8888, manufactured by Arkema Corporation): 50 parts by mass ・Cyclic trimethylolpropane formal acrylate: 50 parts by mass ・Photopolymerization initiator (“Irgacure 1173” manufactured by BASF): 2.0 parts by mass
＜参考例Ｃ１：基材Ｃ－１＞
　基材Ｃ－１として、ＰＥＴフィルム（東洋紡株式会社製「コスモシャインＡ４３００」、両面易接着層付ＰＥＴフィルム、厚み：５０μｍ）を準備した。 <Reference example C1: Base material C-1>
As the substrate C-1, a PET film ("Cosmoshine A4300" manufactured by Toyobo Co., Ltd., PET film with easy adhesive layer on both sides, thickness: 50 μm) was prepared.
＜参考例Ｃ２：基材Ｃ－２＞
　基材Ｃ－２として、ポリオレフィン（ＰＯ）フィルム（低密度ポリオレフィンフィルム、厚み：２５μ））を準備した。 <Reference example C2: Base material C-2>
A polyolefin (PO) film (low-density polyolefin film, thickness: 25 μm) was prepared as the substrate C-2.
［測定方法及び評価方法］
＜緩衝層及び基材の各種物性値の測定・算出＞
　基材及び緩衝層の弾性率、破断エネルギー、破断応力、及び破断ひずみは、精密万能試験機（株式会社島津製作所製装置名「オートグラフＡＧ－ＩＳ」）を用いて測定した。
　具体的には、緩衝層Ａ－１～Ａ－４、緩衝層Ｂ－１～Ｂ－３、基材Ｃ－１～基材Ｃ－２について、幅１．５ｍｍ×長さ１５０ｍｍ×厚さ０．２ｍｍの測定用サンプルを作製した。そして、当該測定用サンプルについて、チャック間１００ｍｍ（測定用サンプルの長手方向の両端２５ｍｍずつを装置に固定）、引張速度２００ｍｍ／ｓｅｃ、２３℃、５０％ＲＨの条件にて、測定を行った。また、その際に得られた応力－ひずみデータから、緩衝層Ａ－１～Ａ－４、緩衝層Ｂ―１～Ｂ－３、基材Ｃ－１～基材Ｃ－２について、破断ひずみ（ε１００）の８０％のひずみ（ε８０）が破断ひずみ（ε１００）に増加するまでの、応力の増加勾配Δρ８０－１００を算出した。また、破断応力と破断ひずみ（ε１００）の積も算出した。 [Measurement method and evaluation method]
<Measurement and calculation of various physical property values of buffer layer and base material>
The elastic modulus, breaking energy, breaking stress, and breaking strain of the base material and the buffer layer were measured using a precision universal testing machine (manufactured by Shimadzu Corporation, device name "Autograph AG-IS").
Specifically, for buffer layers A-1 to A-4, buffer layers B-1 to B-3, and base materials C-1 to C-2, width 1.5 mm x length 150 mm x thickness 0. A measurement sample of .2 mm was prepared. Then, measurements were performed on the measurement sample under conditions of a chuck distance of 100 mm (25 mm of each longitudinal end of the measurement sample were fixed to the device), a tensile speed of 200 mm/sec, 23° C., and 50% RH. In addition, from the stress-strain data obtained at that time, the breaking strain ( The stress increase slope Δρ 80-100 until the strain (ε 80 ) of 80% of ε 100 ) increases to the breaking strain (ε 100 ) was calculated. Moreover, the product of breaking stress and breaking strain (ε 100 ) was also calculated.
＜刃による切断性の評価（１）：シミュレーションによる評価＞
　汎用有限要素解析ソフトウエアである「Ａｂａｑｕｓ」を用い、半導体加工用粘着テープを刃で切断した際の断面の状態をシミュレーションにより評価した。
　解析モデルを図３に示す。
　半導体ウエハは長方形とし、該半導体ウエハ上に緩衝層と基材とが積層した積層構造を有する半導体加工用粘着テープを積層した解析モデルを想定した。なお、当該解析モデルでは、半導体加工用粘着テープの一方の端部は半導体ウエハに拘束された状態であり、もう一方の端部は外周テーブル側に完全拘束された状態を想定した。そして、緩衝層表面と刃の刃先との成す角度を５７．２°に設定し、切断速度８０ｍｍ／ｓで、刃を半導体ウエハの沿った直線方向に移動させたときの半導体加工用粘着テープの断面の状態を解析した。
　なお、上記解析モデルにおいて、刃物性は剛体とした。
　また、刃については、アートナイフ（ＯＬＦＡ社製、型番「ＸＢ１０」）の使用を想定し、当該アートナイフのうち、切断に関与する箇所のみをモデル化して、寸法を入力した。
　緩衝層及び基材は、以下の組み合わせで解析した。
・実施例１ｓｉｍ．：緩衝層Ａ－１／ＰＥＴ
・実施例２ｓｉｍ．：緩衝層Ａ－２／ＰＥＴ
・実施例３ｓｉｍ．：緩衝層Ａ－３／ＰＥＴ
・実施例４ｓｉｍ．：緩衝層Ａ－４／ＰＥＴ
・比較例１ｓｉｍ．：緩衝層Ｂ－１／ＰＥＴ
・比較例２ｓｉｍ．：緩衝層Ｂ－２／ＰＥＴ
・比較例３ｓｉｍ．：緩衝層Ｂ－３／ＰＥＴ
・参考例１ｓｉｍ．：ＰＥＴ
・参考例２ｓｉｍ．：ＰＯ
　緩衝層の厚さは２８μｍとした。基材の厚さは５０μｍとした。
　また、緩衝層及び基材の物性値として、上記精密万能試験機により測定した応力－ひずみデータと、当該データに基づく弾性率、降伏応力、及び破断点を入力した。
　なお、刃と緩衝層間の摩擦係数は０．２５に設定した。 <Evaluation of cutting performance by blade (1): Evaluation by simulation>
Using "Abaqus", a general-purpose finite element analysis software, the state of the cross section when the adhesive tape for semiconductor processing was cut with a blade was evaluated by simulation.
The analytical model is shown in Figure 3.
The semiconductor wafer was assumed to be rectangular, and an analytical model was assumed in which an adhesive tape for semiconductor processing having a laminated structure in which a buffer layer and a base material were laminated was laminated on the semiconductor wafer. In this analysis model, it is assumed that one end of the adhesive tape for semiconductor processing is restrained to the semiconductor wafer, and the other end is completely restrained to the outer peripheral table side. The angle between the surface of the buffer layer and the cutting edge of the blade was set to 57.2°, and the blade was moved in a straight line along the semiconductor wafer at a cutting speed of 80 mm/s. The state of the cross section was analyzed.
In addition, in the above analysis model, the blade property was assumed to be a rigid body.
Regarding the blade, assuming the use of an art knife (manufactured by OLFA, model number "XB10"), only the parts of the art knife involved in cutting were modeled and the dimensions were entered.
The buffer layer and base material were analyzed in the following combinations.
・Example 1 sim. :Buffer layer A-1/PET
・Example 2 sim. :Buffer layer A-2/PET
・Example 3 sim. :Buffer layer A-3/PET
・Example 4sim. :Buffer layer A-4/PET
・Comparative example 1sim. :Buffer layer B-1/PET
・Comparative example 2sim. :Buffer layer B-2/PET
・Comparative example 3sim. :Buffer layer B-3/PET
・Reference example 1sim. :PET
・Reference example 2sim. :P.O.
The thickness of the buffer layer was 28 μm. The thickness of the base material was 50 μm.
In addition, as physical property values of the buffer layer and the base material, stress-strain data measured by the above-mentioned precision universal testing machine, elastic modulus, yield stress, and breaking point based on the data were input.
Note that the friction coefficient between the blade and the buffer layer was set to 0.25.
　評価基準は、以下のとおりとし、３以上を合格とした。
１：シート断面が非常に荒れている。
２：シート断面が荒れている。
３：シート断面がやや荒れている。
４：シート断面に荒れが僅かに見られる程度である。
５：シート断面に荒れが見られない。 The evaluation criteria were as follows, and a rating of 3 or higher was considered a pass.
1: The cross section of the sheet is extremely rough.
2: The cross section of the sheet is rough.
3: The cross section of the sheet is slightly rough.
4: Slight roughness is observed in the cross section of the sheet.
5: No roughness is observed in the cross section of the sheet.
＜刃による切断性の評価（２）：実験による評価＞
　下記構成の半導体加工用粘着テープを準備した。
・実施例１ｅｘｐ．：衝層Ａ－１／ＰＥＴ／粘着剤層
・比較例３ｅｘｐ．：緩衝層Ｂ－３／ＰＥＴ／粘着剤層 <Evaluation of cutting performance by blade (2): Evaluation by experiment>
An adhesive tape for semiconductor processing having the following configuration was prepared.
・Example 1exp. : Throat layer A-1/PET/adhesive layer/Comparative example 3exp. :Buffer layer B-3/PET/adhesive layer
（粘着剤層の形成）
　ｎ－ブチルアクリレート（ＢＡ）６５質量部、メチルメタクリレート（ＭＭＡ）２０質量部、及び２－ヒドロキシエチルアクリレート（２ＨＥＡ）１５質量部を共重合して得たアクリル系重合体に、当該アクリル系重合体の全水酸基のうち８０モル％の水酸基に付加するように、２－メタクリロイルオキシエチルイソシアネート（ＭＯＩ）を反応させて、エネルギー線硬化性のアクリル系樹脂（Ｍｗ：５０万）を得た。
　このエネルギー線硬化性のアクリル系樹脂１００質量部に、エネルギー線硬化性化合物である多官能ウレタンアクリレートを６質量部、イソシアネート系架橋剤（東ソー株式会社製「コロネートＬ」）を０．３７５質量部、光重合開始剤としてビス（２，４，６－トリメチルベンゾイル）フェニルフォスフィンオキシドを１質量部配合し、メチルエチルケトンで希釈し、固形分濃度３２質量％の粘着剤組成物の塗工液を調製した。 (Formation of adhesive layer)
An acrylic polymer obtained by copolymerizing 65 parts by mass of n-butyl acrylate (BA), 20 parts by mass of methyl methacrylate (MMA), and 15 parts by mass of 2-hydroxyethyl acrylate (2HEA), An energy ray-curable acrylic resin (Mw: 500,000) was obtained by reacting 2-methacryloyloxyethyl isocyanate (MOI) so as to add to 80 mol% of the total hydroxyl groups.
To 100 parts by mass of this energy ray-curable acrylic resin, 6 parts by mass of polyfunctional urethane acrylate, which is an energy ray-curable compound, and 0.375 parts by mass of an isocyanate-based crosslinking agent ("Coronate L" manufactured by Tosoh Corporation). , 1 part by mass of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide was blended as a photopolymerization initiator and diluted with methyl ethyl ketone to prepare a coating solution of an adhesive composition with a solid content concentration of 32% by mass. did.
（半導体加工用粘着テープの作製）
　剥離シート（リンテック社製、商品名「ＳＰ－ＰＥＴ３８１０３１」）の剥離処理面に、上記で得た粘着剤組成物の塗工液を塗工し、加熱乾燥させて、剥離シート上に厚さが３０μｍの粘着剤層を形成した。
　そして、製造例Ａ１で形成した緩衝層Ａ－１付きＰＥＴ基材のＰＥＴ基材側の面に、粘着剤層を貼り合わせ、緩衝層Ａ－１／ＰＥＴ基材／粘着剤層の積層構造を有する半導体加工用粘着テープを作製した。
　同様に、比較製造例Ｂ３で形成した緩衝層Ｂ－３付きＰＥＴ基材のＰＥＴ基材側の面に、粘着剤層を貼り合わせ、緩衝層Ｂ－３／ＰＥＴ基材／粘着剤層の積層構造を有する半導体加工用粘着テープを作製した。 (Production of adhesive tape for semiconductor processing)
The coating solution of the adhesive composition obtained above is applied to the release-treated surface of a release sheet (manufactured by Lintec Corporation, trade name "SP-PET381031"), and the coating liquid of the adhesive composition obtained above is heated and dried to form a thick layer on the release sheet. A 30 μm adhesive layer was formed.
Then, an adhesive layer is attached to the PET base material side surface of the PET base material with the buffer layer A-1 formed in Production Example A1 to form a laminated structure of buffer layer A-1/PET base material/adhesive layer. An adhesive tape for semiconductor processing was produced.
Similarly, an adhesive layer was attached to the PET base material side surface of the PET base material with buffer layer B-3 formed in Comparative Production Example B3, and the lamination of buffer layer B-3/PET base material/adhesive layer was performed. An adhesive tape for semiconductor processing with a structure was produced.
（評価）
　実施例１ｅｘｐ．及び比較例３ｅｘｐ．の半導体加工用粘着テープを、直径１２インチ、厚み７７５μｍのシリコンウエハに、バックグラインド用テープラミネーター（リンテック社製、装置名「ＲＡＤ－３５１０Ｆ／１２」）を用いて貼付した。そして、半導体加工用粘着テープを、シリコンウエハの外周に沿って、アートナイフ（ＯＬＦＡ社製、型番「ＸＢ１０」）で切断した。アートナイフは、半導体加工用粘着テープの緩衝層側から入刃した。緩衝層表面と刃の刃先との成す角度は５７．２°とした。また、切断速度は８０ｍｍ／ｓとした。切断した半導体加工用粘着テープの断面を走査型電子顕微鏡（ＳＥＭ）で観察し、シート断面の評価（１）と同様の基準にて評価した。 (evaluation)
Example 1exp. and Comparative Example 3exp. An adhesive tape for semiconductor processing was attached to a silicon wafer having a diameter of 12 inches and a thickness of 775 μm using a backgrinding tape laminator (manufactured by Lintec Corporation, device name: “RAD-3510F/12”). Then, the adhesive tape for semiconductor processing was cut along the outer periphery of the silicon wafer with an art knife (manufactured by OLFA, model number "XB10"). The art knife was inserted from the buffer layer side of the adhesive tape for semiconductor processing. The angle formed between the surface of the buffer layer and the cutting edge of the blade was 57.2°. Moreover, the cutting speed was 80 mm/s. The cross section of the cut adhesive tape for semiconductor processing was observed using a scanning electron microscope (SEM), and evaluated using the same criteria as the evaluation of the sheet cross section (1).
　「刃による切断性の評価（１）：シミュレーションによる評価」の結果のうち、実施例と比較例の結果を表１に示し、参考例の結果を表２に示す。
　また、「刃による切断性の評価（２）：実験による評価」の結果を表３に示す。
　さらに、「刃による切断性の評価（１）：シミュレーションによる評価」における実施例１ｓｉｍ．と比較例３ｓｉｍ．の解析画像を図４に示し、「刃による切断性の評価（２）：実験による評価」における走査型電子顕微鏡（ＳＥＭ）の観察結果を図５に示す。 Among the results of "Evaluation of Cuttability by Blade (1): Evaluation by Simulation", the results of Examples and Comparative Examples are shown in Table 1, and the results of Reference Examples are shown in Table 2.
In addition, Table 3 shows the results of "Evaluation of Cuttability by Blade (2): Experimental Evaluation".
Furthermore, Example 1sim in "Evaluation of cutting performance by blade (1): Evaluation by simulation". and Comparative Example 3sim. An analysis image is shown in FIG. 4, and FIG. 5 shows the observation results of a scanning electron microscope (SEM) in "Evaluation of Cuttability by Blade (2): Experimental Evaluation".
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　表１より、以下のことがわかる。
　緩衝層が要件（α）及び要件（β）を満たす実施例１ｓｉｍ．、実施例２ｓｉｍ．、実施例３ｓｉｍ．、実施例４ｓｉｍ．では、いずれも刃による切断性が良好であることがわかる。
　これに対し、比較例１ｓｉｍ．、比較例２ｓｉｍ．では、緩衝層が要件（β）を満たしておらず、いずれも刃による切断性に劣ることがわかる。
　また、比較例３ｓｉｍ．では、緩衝層が要件（α）も要件（β）も満たしておらず、刃による切断性に極めて劣ることがわかる。 From Table 1, the following can be seen.
Example 1 sim. in which the buffer layer satisfies the requirements (α) and (β). , Example 2 sim. , Example 3 sim. , Example 4sim. It can be seen that the cutting performance by the blade is good in all cases.
In contrast, Comparative Example 1sim. , Comparative Example 2sim. It can be seen that the buffer layer does not satisfy the requirement (β) in both cases, and the cutting performance with the blade is poor in both cases.
Moreover, Comparative Example 3sim. It can be seen that the buffer layer does not satisfy either requirement (α) or requirement (β), and has extremely poor cutting performance with a blade.
　表２より、以下のことがわかる。
　基材が要件（γ）を満たす参考例１ｓｉｍ．及び参考例２ｓｉｍ．では、いずれも刃による切断性が良好であることがわかる。
　ここで、参考例２ｓｉｍ．では、要件（β）を満たしていないにもかかわらず、刃による切断性が良好であることから、基材については、要件（α）及び要件（β）による切断性の良否を判断できないことがわかる。 From Table 2, the following can be seen.
Reference example 1sim where the base material satisfies the requirement (γ). and Reference Example 2sim. It can be seen that the cutting performance by the blade is good in all cases.
Here, Reference Example 2sim. In this case, since the cutting performance of the blade is good even though requirement (β) is not met, it is not possible to judge whether the cutting performance of the base material is good or bad based on requirement (α) and requirement (β). Recognize.
　表３より、以下のことがわかる。
　表３に示す実施例１ｅｘｐ．及び比較例３ｅｘｐ．は、実施例１ｓｉｍ．及び比較例３ｓｉｍ．を実験的に確かめた結果である。実施例１ｅｘｐ．及び比較例３ｅｘｐ．により検討した刃による切断性の評価結果は、実施例１ｓｉｍ．及び比較例３ｓｉｍ．により検討した刃による切断性の評価結果と完全に一致していることがわかる。
　このことは、図４及び図５に示す結果からも明らかである。 From Table 3, the following can be seen.
Example 1exp. shown in Table 3. and Comparative Example 3exp. is Example 1 sim. and Comparative Example 3sim. These are the results of experimental confirmation. Example 1exp. and Comparative Example 3exp. The evaluation results of the cutting performance by the blade examined in Example 1 sim. and Comparative Example 3sim. It can be seen that the results are in complete agreement with the evaluation results of the cutting performance of the blade investigated by
This is also clear from the results shown in FIGS. 4 and 5.
１　　半導体加工用粘着テープ
１１　緩衝層
１２　基材
１３　粘着剤層

  1 Adhesive tape for semiconductor processing 11 Buffer layer 12 Base material 13 Adhesive layer

Claims (9)

  1. 　緩衝層と、基材と、粘着剤層とがこの順で積層された積層構造を有し、
    　前記緩衝層が、下記要件（α）及び下記要件（β）の双方を満たす、半導体加工用粘着テープ。
    ・要件（α）：前記緩衝層の２３℃における破断エネルギーが１５ＭＪ／ｍ３以上である。
    ・要件（β）：温度２３℃において前記緩衝層を引張試験に供したときに、破断ひずみ（ε１００）の８０％のひずみ（ε８０）が前記破断ひずみ（ε１００）に増加するまでの、応力の増加勾配Δρ８０－１００が、３０ＭＰａ以上である。     It has a laminated structure in which a buffer layer, a base material, and an adhesive layer are laminated in this order,
    An adhesive tape for semiconductor processing, wherein the buffer layer satisfies both the following requirements (α) and the following requirements (β).
    - Requirement (α): The breaking energy of the buffer layer at 23° C. is 15 MJ/m 3 or more.
    ・Requirement (β): When the buffer layer is subjected to a tensile test at a temperature of 23°C, the strain (ε 80 ) that is 80% of the breaking strain (ε 100 ) increases to the breaking strain (ε 100 ). , the stress increase gradient Δρ 80-100 is 30 MPa or more.
  2. 　前記基材が、下記要件（γ）を満たす、請求項１に記載の半導体加工用粘着テープ。
    ・要件（γ）：温度２３℃における破断ひずみ（ε１００）と温度２３℃における破断応力（ρ１００）との積が、６０ＭＰａ以上である。     The adhesive tape for semiconductor processing according to claim 1, wherein the base material satisfies the following requirement (γ).
    - Requirement (γ): The product of the breaking strain (ε 100 ) at a temperature of 23°C and the breaking stress (ρ 100 ) at a temperature of 23°C is 60 MPa or more.
  3. 　前記粘着剤層の厚さが、１００μｍ未満である、請求項１又は２に記載の半導体加工用粘着テープ。 The adhesive tape for semiconductor processing according to claim 1 or 2, wherein the adhesive layer has a thickness of less than 100 μm.
  4. 　請求項１～３のいずれか１項に記載の半導体加工用粘着テープの使用方法であって、
    　半導体ウエハを裏面研削する際に、前記半導体加工用粘着テープを半導体ウエハの表面に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する、使用方法。     A method of using the adhesive tape for semiconductor processing according to any one of claims 1 to 3, comprising:
    A method of use in which the adhesive tape for semiconductor processing is affixed to the surface of the semiconductor wafer and the adhesive tape for semiconductor processing is cut along the outer periphery of the semiconductor wafer when back grinding the semiconductor wafer.
  5. 　請求項１～３のいずれか１項に記載の半導体加工用粘着テープを半導体ウエハの表面に貼付し、前記半導体加工用粘着テープを前記半導体ウエハの外周に沿って切断する工程（Ｓ１）を含む、半導体装置の製造方法。 A step (S1) of attaching the adhesive tape for semiconductor processing according to any one of claims 1 to 3 to the surface of a semiconductor wafer and cutting the adhesive tape for semiconductor processing along the outer periphery of the semiconductor wafer. , a method for manufacturing a semiconductor device.
  6. 　請求項５に記載の半導体装置の製造方法において、
    　さらに、下記工程（Ｓ２）を含む、半導体装置の製造方法。
    ・工程（Ｓ２）：前記半導体ウエハを裏面側から研削する工程     The method for manufacturing a semiconductor device according to claim 5,
    Furthermore, a method for manufacturing a semiconductor device, including the following step (S2).
    ・Step (S2): Step of grinding the semiconductor wafer from the back side
  7. 　請求項６に記載の半導体装置の製造方法において、
    　さらに、下記工程（Ｓ３）を含む、半導体装置の製造方法。
    ・工程（Ｓ３）：前記半導体ウエハをダイシングして個片化する工程     The method for manufacturing a semiconductor device according to claim 6,
    Furthermore, a method for manufacturing a semiconductor device including the following step (S3).
    ・Step (S3): Step of dicing the semiconductor wafer into individual pieces
  8. 　請求項６に記載の半導体装置の製造方法において、
    　前記半導体ウエハとして、表面側に溝が形成された半導体ウエハを用い、
    　前記工程（Ｓ２）において、前記半導体ウエハを、前記溝を起点として複数のチップに個片化させる、製造方法。     The method for manufacturing a semiconductor device according to claim 6,
    As the semiconductor wafer, a semiconductor wafer with grooves formed on the front side is used,
    In the step (S2), the semiconductor wafer is singulated into a plurality of chips using the groove as a starting point.
  9. 　請求項６に記載の半導体装置の製造方法において、
    　前記半導体ウエハとして、内部に改質領域が形成された半導体ウエハを用いるか、又は、前記工程（Ｓ１）の後に前記半導体ウエハの内部に改質領域を形成し、
    　前記工程（Ｓ２）において、前記半導体ウエハを、前記改質領域を起点として複数のチップに個片化させる、製造方法。

          The method for manufacturing a semiconductor device according to claim 6,
    As the semiconductor wafer, a semiconductor wafer having a modified region formed therein is used, or a modified region is formed inside the semiconductor wafer after the step (S1),
    In the step (S2), the semiconductor wafer is singulated into a plurality of chips starting from the modified region.
PCT/JP2022/016521 2022-03-31 2022-03-31 Adhesive tape for semiconductor processing WO2023188272A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012209363A (en) * 2011-03-29 2012-10-25 Sumitomo Bakelite Co Ltd Dicing film
WO2017150676A1 (en) * 2016-03-03 2017-09-08 リンテック株式会社 Adhesive tape for semiconductor processing and method for producing semiconductor device
WO2020003919A1 (en) * 2018-06-26 2020-01-02 リンテック株式会社 Semiconductor processing adhesive tape and method of manufacturing semiconductor device
WO2020003920A1 (en) * 2018-06-26 2020-01-02 リンテック株式会社 Adhesive tape for semiconductor processing and method for producing semiconductor device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012209363A (en) * 2011-03-29 2012-10-25 Sumitomo Bakelite Co Ltd Dicing film
WO2017150676A1 (en) * 2016-03-03 2017-09-08 リンテック株式会社 Adhesive tape for semiconductor processing and method for producing semiconductor device
WO2020003919A1 (en) * 2018-06-26 2020-01-02 リンテック株式会社 Semiconductor processing adhesive tape and method of manufacturing semiconductor device
WO2020003920A1 (en) * 2018-06-26 2020-01-02 リンテック株式会社 Adhesive tape for semiconductor processing and method for producing semiconductor device

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