Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers
  • C09J7/22—Plastics; Metallised plastics
  • C09J7/24—Plastics; Metallised plastics based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
  • C09J7/38—Pressure-sensitive adhesives [PSA]

Definitions

• the present invention when a workpiece such as a semiconductor wafer (hereinafter sometimes referred to as “work”) is subjected to temporary surface protection, polishing, dicing, or the like, the workpiece is stuck and held.
• the present invention relates to an adhesive tape preferably used as a workpiece processing tape.
• this invention relates to the adhesive composition preferably used for this adhesive tape.
• Semiconductor wafers such as silicon and gallium arsenide are manufactured in a large diameter state. After a circuit is formed on the surface of a semiconductor wafer, the semiconductor wafer is ground to a predetermined thickness by backside grinding, and is cut and separated (diced) into element small pieces (semiconductor chips), and then transferred to the next bonding process.
• Various adhesive tapes are used in these series of steps.
• an adhesive tape called a back grind tape is used to hold the wafer during grinding and to protect the circuit surface from grinding debris. Further, following the back surface grinding process, circuit formation or the like may be performed on the ground surface, and also in this case, the wafer is protected and fixed with an adhesive tape for processing.
• a surface protection tape for backside processing such as a back grind tape is composed of a base material and a pressure-sensitive adhesive layer having pressure-sensitive adhesiveness. In order to reliably protect the circuit surface, an adhesive tape using an adhesive that is relatively soft and has high stress relaxation properties may be used.
• the pressure-sensitive adhesive tape used in the dicing process is also called a dicing tape, and is composed of a base material and a pressure-sensitive adhesive layer having pressure-sensitive adhesiveness.
• a pressure-sensitive adhesive tape having a relatively soft base material may be used in order to facilitate expansion for separating the chips.
• a method called wireless bonding is used when a chip separated by dicing is placed on a substrate.
• This method performs electrical connection between a chip and a substrate without using a thin metal wire.
• a protruding electrode called a bump provided on a chip circuit surface, an electrode on the substrate, The electrical connection is ensured by bringing them into contact with each other.
• This mounting method is called face-down mounting or flip-chip mounting, and contributes to the miniaturization of the element.
• a circuit is formed on the surface of a semiconductor wafer, a protrusion is formed on the circuit surface, a back grind tape is applied to the surface, and the back surface is ground. Process and adjust the thickness. Thereafter, the semiconductor wafer is held on a dicing tape, and the semiconductor wafer is diced into chips.
• the back grind tape is required to follow the uneven surface and to protect the circuit surface with certainty. If the followability of the back grind tape is insufficient, grinding dust or the like may enter the circuit surface during grinding of the back surface, which may contaminate or damage the circuit. Therefore, the back grind tape is required to be embedded in a fine uneven surface.
• an adhesive tape comprising a base material, an intermediate layer, and an adhesive layer
• Patent Documents 1 and 2 an adhesive tape comprising a base material, an intermediate layer, and an adhesive layer
• the height difference of the wafer surface is absorbed by the intermediate layer and follows the circuit surface.
• many of the intermediate layers in the document are made of a polyolefin-based polymer, and many of the pressure-sensitive adhesive layers are made of an acrylic polymer.
• Polyolefin polymers and acrylic polymers generally have a low affinity. For this reason, when the back grind tape is peeled off from the circuit surface of the semiconductor wafer, peeling occurs between the intermediate layer and the adhesive layer, which may cause a problem that the adhesive remains on the circuit surface of the semiconductor wafer. is there.
• an adhesive tape having a two-layer structure composed of a base material and an adhesive layer is also known.
• an adhesive tape in order to follow the irregularities on the surface of the semiconductor wafer, it is considered to increase the thickness of the adhesive layer or make the adhesive layer relatively soft.
• a pressure-sensitive adhesive tape may cause problems such as poor appearance and adhesion of the pressure-sensitive adhesive to the circuit surface of the semiconductor wafer.
• ⁇ Adhesive tape is generally wound into a roll and stored and transported. At this time, a winding pressure is applied to the pressure-sensitive adhesive tape, and a part of the pressure-sensitive adhesive layer or the intermediate layer leaks to the roll end surface.
• the resin component may be exposed to an environment of about 40 ° C., and the leakage of the resin component becomes significant. The resin component leaked to the end face of the roll becomes a cause of poor appearance of the end portion, and dust or the like adheres to the semiconductor wafer. Further, when the pressure-sensitive adhesive layer is made relatively soft, the followability to the irregularities on the surface of the semiconductor wafer is improved.
• the pressure-sensitive adhesive layer may be stretched and broken at the time of peeling, and a part of the pressure-sensitive adhesive may remain on the wafer circuit surface (adhesive residue) and contaminate the circuit surface.
• the object of the present invention is to eliminate the adhesive residue on the workpiece and the end appearance defect in the adhesive tape used as a back grind tape or dicing tape.
• the adhesive tape when sticking an adhesive tape on an uneven surface, the adhesive tape is heated to about 40 to 60 ° C. to improve the fluidity and embedding property of the adhesive layer (or intermediate layer) and then sticking.
• leakage of the pressure-sensitive adhesive (or intermediate layer) during storage which is a cause of poor appearance of the edge, is caused by the flow of the pressure-sensitive adhesive (or intermediate layer) at room temperature to about 40 ° C. Therefore, the present inventors have studied in detail the viscoelastic behavior of the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer (or intermediate layer).
• the storage elastic modulus G ′ (23) at 23 ° C. is 1.0 ⁇ 10 5 Pa or more
• the storage elastic modulus G ′ (50) at 50 ° C. is 2.5 ⁇ 10 5 Pa or less
• Tan ⁇ of dynamic viscoelasticity at 60 ° C. is 0.5 or more
• An adhesive composition comprising an acrylic polymer as a main component.
• the ratio of the storage elastic modulus G ′ (60) at 60 ° C. to the storage elastic modulus G ′ (23) at 23 ° C., and G ′ (60) / G ′ (23) is 0.1 to 0.7.
• the adhesive composition as set forth in (1).
• a pressure-sensitive adhesive tape comprising a substrate and a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer comprises the pressure-sensitive adhesive composition according to (1) or (2).
• a pressure-sensitive adhesive tape comprising a base material, a pressure-sensitive adhesive layer, and an intermediate layer between the base material and the pressure-sensitive adhesive layer, wherein the intermediate layer contains the pressure-sensitive adhesive composition according to (1) or (2).
• the peak value of tan ⁇ can generally be confirmed in a low temperature range of about ⁇ 50 to 0 ° C., and tan ⁇ decreases as the temperature rises.
• the elastic modulus decreases with increasing temperature.
• the present inventors have made various studies on the viscoelasticity of the acrylic polymer that is the main component of the pressure-sensitive adhesive composition. The viscoelasticity is such that the fluidity is suppressed at room temperature to about 40 ° C.
• Using such an acrylic polymer as the main component of the adhesive composition makes it easy to control the fluidity of the adhesive layer (or intermediate layer) during application and storage, and follows the uneven surface of the workpiece during application.
• an adhesive tape with little leakage of the adhesive composition during storage is provided.
• the pressure-sensitive adhesive tape means a laminate including a base material and a pressure-sensitive adhesive layer, and does not prevent other constituent layers from being included.
• an intermediate layer may be provided between the base material and the pressure-sensitive adhesive layer, and the base material surface on the pressure-sensitive adhesive layer side includes the base material surface and the pressure-sensitive adhesive layer interface, or the base material surface and the intermediate layer.
• a primer layer may be formed for the purpose of improving adhesion at the interface and preventing migration of low molecular weight components, etc., and a release film for protecting the adhesive layer is laminated on the surface of the adhesive layer until use May be.
• the substrate may be a single layer or a multilayer having a functional layer such as a buffer layer.
• the adhesive composition of the present invention described below is preferably used for an adhesive layer or an intermediate layer of an adhesive tape.
• the back grind tape refers to an adhesive tape used for protecting the wafer circuit surface when grinding the back surface of a semiconductor wafer.
• the dicing tape refers to an adhesive tape used for holding a wafer and chips when the wafer is divided into chips for each circuit.
• the “front surface” of the semiconductor wafer refers to the surface on which the circuit is formed, and the “back surface” refers to the surface on which the circuit is not formed.
• the pressure-sensitive adhesive composition of the present invention contains an acrylic polymer and satisfies the following viscoelastic behavior.
• the viscoelasticity of an adhesive composition is based on a solid component, and when an adhesive composition is a solution form, it means the viscoelasticity of the adhesive substance obtained by drying a solution.
• an adhesive composition consists only of an acrylic polymer, it means the property of acrylic polymer itself.
• the following physical property points out the physical property before hardening an adhesive composition by energy ray irradiation.
• the storage elastic modulus G ′ (23) at 23 ° C. of the adhesive composition is preferably 1.0 ⁇ 10 5 Pa or more, more preferably 1.2 ⁇ 10 5 Pa or more, more preferably 1. 3 ⁇ 10 5 to 8.0 ⁇ 10 5 Pa, particularly preferably 1.7 ⁇ 10 5 to 7.0 ⁇ 10 5 Pa.
• the storage elastic modulus G ′ (23) of the adhesive composition is in the above range, the fluidity at room temperature to about 40 ° C. is suppressed. As a result, even if the pressure-sensitive adhesive tape is stored and transported in a roll form, the pressure-sensitive adhesive composition does not leak from the roll end face, and the appearance of the roll end can be maintained well.
• the storage elastic modulus G ′ (50) at 50 ° C. of the adhesive composition is preferably 2.5 ⁇ 10 5 Pa or less, more preferably 2.4 ⁇ 10 5 Pa or less, more preferably 7. It is 0 ⁇ 10 4 to 2.3 ⁇ 10 5 Pa, and particularly preferably 8.0 ⁇ 10 4 to 2.2 ⁇ 10 5 Pa.
• the storage elastic modulus G ′ (50) of the adhesive composition is in the above range, an appropriate fluidity can be obtained when the adhesive tape is heated to about 40 to 60 ° C. and applied. Improves embedding in unevenness.
• the tan ⁇ of dynamic viscoelasticity at 60 ° C. of the adhesive composition (hereinafter sometimes referred to as “tan ⁇ (60)”) is preferably 0.5 or more, more preferably 0.51 or more. More preferably, it is 0.52 to 0.8, and particularly preferably 0.53 to 0.75.
• Tan ⁇ of the adhesive composition is obtained as follows. That is, a sample having a predetermined shape is obtained from the adhesive composition, a strain having a frequency of 1 Hz is applied to the sample, and the storage elastic modulus G ′ and the loss elastic modulus G ′′ at each measurement temperature are measured. The loss tangent tan ⁇ (G ′′ / G ′) at 60 ° C. is calculated to obtain tan ⁇ (60).
• the pressure-sensitive adhesive composition of the present invention preferably satisfies the following viscoelasticity.
• the ratio of the storage elastic modulus G ′ (60) at 60 ° C. to the storage elastic modulus G ′ (23) at 23 ° C. of the adhesive composition, G ′ (60) / G ′ (23) is preferably 0.1. It is -0.7, More preferably, it is 0.2-0.6, More preferably, it is 0.21-0.45, Most preferably, it is 0.23-0.41.
• G '(60) / G' (23) is within the above range, the adhesive composition or intermediate layer will not flow excessively even if the adhesive layer or intermediate layer is heated, so that the adhesive composition will not enter the fine structure of the circuit surface. . For this reason, even if it peels an adhesive tape after completion
• the pressure-sensitive adhesive composition has a plurality of, preferably two, maximum values of tan ⁇ of dynamic viscoelasticity.
• the polymer includes a site corresponding to a normal adhesive polymer, and a zwitterion Coexists with sites derived from the contained units. Since the viscoelastic behaviors of the two are different, it is considered that a plurality of maximum values of tan ⁇ appear.
• the maximum value of tan ⁇ on the low temperature side appears in the range of ⁇ 50 to 0 ° C.
• the maximum value of tan ⁇ on the high temperature side appears in the range of 10 to 60 ° C.
• the adhesive tape Since it has a maximum value of tan ⁇ on the low temperature side, it has excellent adhesive strength at room temperature, especially initial adhesive strength. In addition, since it has a maximum value of tan ⁇ on the high temperature side, the adhesive tape is heated to about 40 to 60 ° C., and the adhesive is embedded in the irregularities on the surface of the semiconductor wafer. Contamination and breakage of the circuit surface due to water can be reduced.
• the pressure-sensitive adhesive composition according to the present invention contains an acrylic polymer as a main component.
• the acrylic polymer is a polymer mainly composed of a repeating unit derived from (meth) acrylic acid or an ester which is a derivative thereof, and may be a modified polymer.
• Various physical properties of the adhesive composition described above are mainly attributed to the acrylic polymer. Therefore, the adhesive composition of the present invention can be obtained by selecting an acrylic polymer having an appropriate viscoelasticity.
• the acrylic polymer used preferably is demonstrated below, these are non-limiting illustrations and the acrylic polymer of this invention is not limited to the following. Based on the following description and common technical knowledge, other acrylic polymers that can be used in the present invention can be obtained by appropriately adjusting the structure of the polymer.
• the pressure-sensitive adhesive composition according to the present invention preferably contains an acrylic polymer having a repeating unit containing a zwitterionic structure and a repeating unit derived from a (meth) acrylic monomer as an acrylic polymer.
• a repeating unit containing a zwitterionic structure is referred to as a “zwitterion-containing unit”
• a repeating unit derived from a (meth) acrylic monomer is referred to as a “(meth) acrylic unit”.
• a polymer containing is sometimes referred to as a “zwitter ion-containing acrylic polymer”.
• the zwitterion-containing acrylic polymer includes a repeating unit containing a zwitterionic structure.
• the zwitterionic structure refers to a polarization structure including a positive charge and a negative charge.
• the zwitterion-containing acrylic polymer preferably has a zwitterionic structure in the side chain of the polymer.
• the zwitterionic structure is not particularly limited as long as it has a polarization structure, but from the viewpoint of production convenience, the positive charge is preferably a positive charge derived from a quaternary ammonium, a nitrogen-containing heterocyclic ring or a quaternary phosphonium.
• the negative charge is a sulfo residue (SO 3 ⁇ ) derived from sultone.
• the structure of the main chain of the polymer is not particularly limited, but preferably comprises a carbon skeleton. Therefore, a preferable zwitterion-containing unit is represented by the following formula (1).
• the positive charge is derived from quaternary ammonium will be described as an example. However, the positive charge may be derived from a nitrogen-containing heterocyclic ring or quaternary phosphonium.
• R 1 represents a hydrogen atom or a methyl group
• R 2 and R 3 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an ether bond, with or without an ether bond.
• R 2 and R 3 may be bonded to each other to form a ring.
• m is an integer of 2 to 5, preferably 3 or 4.
• the number of carbon atoms of the alkyl group having 1 to 10 carbon atoms of the alkyl group having 1 to 10 carbon atoms with or without an ether bond of R 2 or R 3 is preferably 1 to 8, and more preferably 1 to 5.
• Examples of the alkyl group having no ether bond include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and an n-hexyl group.
• Examples of the alkyl group having an ether bond include groups represented by the following formula (2) or (3).
• R 4 represents an alkyl group having 1 to 8 carbon atoms
• Z 1 represents an alkylene group having 2 to 9 carbon atoms
• the total number of carbon atoms of R 4 and Z 1 is 3 to 10. * Represents a bond.
• R 5 represents an alkyl group having 1 to 6 carbon atoms
• Z 2 represents an alkylene group having 2 to 7 carbon atoms
• Z 3 represents an alkylene group having 2 to 7 carbon atoms.
• R 5 , Z 2 and Z 3 have a total carbon number of 5 to 10. * Represents a bond.
• the number of carbon atoms of the cyanoalkyl group having 2 to 11 carbon atoms in the cyanoalkyl group having 2 to 11 carbon atoms with or without an ether bond of R 2 or R 3 is preferably 2 to 9, and more preferably 2 to 6 .
• Examples of the cyanoalkyl group having no ether bond include a cyanomethyl group, a 2-cyanoethyl group, a 3-cyanopropyl group, a 4-cyanobutyl group, and a 6-cyanohexyl group.
• Examples of the cyanoalkyl group having an ether bond include groups represented by the following formula (4) or (5).
• R 6 represents a cyanoalkyl group having 2 to 9 carbon atoms
• Z 4 represents an alkylene group having 2 to 9 carbon atoms
• the total number of carbon atoms of R 6 and Z 4 is 4 ⁇ 11. * Represents a bond.
• R 7 represents a cyanoalkyl group having 2 to 7 carbon atoms
• Z 5 represents an alkylene group having 2 to 7 carbon atoms
• Z 6 represents an alkylene group having 2 to 7 carbon atoms.
• the total number of carbon atoms of R 7 , Z 5 and Z 6 is 6 to 11. * Represents a bond.
• the carbon number of the alkenyl group having 2 to 10 carbon atoms of the alkenyl group having 2 to 10 carbon atoms with or without an ether bond of R 2 and R 3 is preferably 2 to 9, and more preferably 2 to 6.
• Examples of the alkenyl group having no ether bond include a vinyl group, an allyl group, a 1-butenyl group, a 2-butenyl group, and a 1-pentenyl group.
• Examples of the alkenyl group having an ether bond include groups represented by the following formula (6) or (7).
• R 8 represents an alkenyl group having 2 to 8 carbon atoms
• Z 7 represents an alkylene group having 2 to 8 carbon atoms
• the total number of carbon atoms of R 8 and Z 7 is 4 to 10. * Represents a bond.
• R 9 represents an alkenyl group having 2 to 6 carbon atoms
• Z 8 represents an alkylene group having 2 to 6 carbon atoms
• Z 9 represents an alkylene group having 2 to 6 carbon atoms.
• R 9 , Z 8 and Z 9 have a total carbon number of 6 to 10. * Represents a bond.
• the unsubstituted aryl group include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.
• the substituent of the aryl group having a substituent include an alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group; an alkoxy group having 1 to 6 carbon atoms such as a methoxy group and an ethoxy group; a fluorine atom and a chlorine atom And the like.
• Examples of the ring formed by combining R 2 and R 3 include a pyrrolidine ring, a piperidine ring, and a morpholine ring.
• a 1 represents a divalent group represented by any of the following formulas (8) to (10).
• a 2 and A 3 each independently represent an alkylene group having 1 to 10 carbon atoms, and n represents an integer of 1 to 10.
• * 1 represents a bond with a carbon atom
• * 2 represents a bond with a nitrogen atom.
• the carbon number of the alkylene group having 1 to 10 carbon atoms of A 2 and A 3 is preferably 1 to 8, and more preferably 1 to 6.
• Examples of the alkylene group having 1 to 10 carbon atoms include linear alkylene groups such as methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group; propane-1,2-diyl group, butane-1,3- Examples include branched alkylene groups such as diyl groups.
• n is an integer of 1 to 10, preferably an integer of 1 to 5.
• the positive charge of the zwitterionic structure is derived from a nitrogen-containing heterocyclic ring or quaternary phosphonium
• zwitterion-containing units in which 3 ) is substituted with the structures of the following formulas (11) to (14).
• R 10 represents an alkyl group having 1 to 10 carbon atoms with or without an ether bond, a cyanoalkyl group having 2 to 11 carbon atoms with or without an ether bond, or a carbon having or not having an ether bond.
• R 11 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms with or without an ether bond, provided that either atom of R 10 or R 11 is present.
• the group does not exist and is in a radical state and represents a bond to the A1.
• * represents a bond to (CH 2 ) m .
• R 12 to R 16 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, which may or may not have an ether bond, provided that any one of R 12 to R 16 (Atom or group does not exist and is in a radical state and represents a bond to A1. * Represents a bond to (CH 2 ) m .)
• R 17 to R 21 each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms with or without an ether bond, provided that any one of R 17 to R 21 is (Atom or group does not exist and is in a radical state and represents a bond to A1. * Represents a bond to (CH 2 ) m .)
• R 22 represents an alkyl group having 1 to 10 carbon atoms with or without an ether bond, a cyanoalkyl group having 2 to 11 carbon atoms with or without an ether bond, or a carbon number with or without an ether bond.
• R 2 represents an alkenyl group having 2 to 10 or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and R 23 and R 24 each independently have 1 to 10 carbon atoms having or not having a hydrogen atom or an ether bond.
• the zwitterion-containing acrylic polymer includes the zwitterion-containing unit and the (meth) acrylic unit.
• the proportion of zwitterion-containing units in the zwitterion-containing acrylic polymer is less than 100% by mass, preferably 30% by mass or less, more preferably, based on the total amount of the zwitterion-containing acrylic polymer. It is 15% by mass or less, particularly preferably 0.1 to 10% by mass, and most preferably 0.5 to 5.0% by mass. If the ratio of zwitterion-containing units in the zwitterion-containing acrylic polymer is too small, the characteristics of the adhesive composition will be difficult to express the characteristics derived from zwitterion-containing units, and will be embedded in uneven surfaces. May deteriorate, and the end appearance may be poor. Moreover, when there are too many ratios of a zwitterion containing unit, sufficient adhesiveness may not be acquired.
• Examples of (meth) acrylic units include repeating units derived from (meth) acrylic acid esters, repeating units derived from (meth) acrylic acid, and repeating units derived from (meth) acrylamide.
• the proportion of the (meth) acrylic unit is more than 0% by weight, preferably 70% by weight or more, more preferably 85% by weight or more, particularly preferably 90%, based on the total amount of the zwitterion-containing acrylic polymer. To 99.9% by mass, most preferably 95 to 99.5% by mass.
• (Meth) acrylate is preferably alkyl (meth) acrylate.
• alkyl (meth) acrylate examples include those having 1 to 20 carbon atoms in the alkyl group, and the alkyl group may be linear or branched.
• alkyl (meth) acrylate examples include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) methacrylate, 2-ethylhexyl (meth) ) Acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate and the like.
• Alkyl (meth) acrylates may be used alone or in combination of two or more.
• the alkyl (meth) acrylate having an alkyl group having 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 whose carbon number of an alkyl group is 4 or more is an alkyl acrylate.
• the proportion of the repeating unit derived from an alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms is preferably 40 based on the total amount of the zwitterion-containing acrylic polymer. It is -98 mass%, More preferably, it is 45-95 mass%, More preferably, it is 50-90 mass%.
• the zwitterion-containing acrylic polymer is used to adjust the elastic modulus and adhesive properties of the adhesive composition.
• a copolymer containing a repeating unit derived from an alkyl (meth) acrylate having 1 to 3 carbon atoms may be used.
• the alkyl (meth) acrylate is preferably an alkyl (meth) acrylate having 1 or 2 carbon atoms, more preferably methyl (meth) acrylate, and most preferably methyl methacrylate.
• the ratio of the repeating unit derived from the alkyl (meth) acrylate having an alkyl group having 1 to 3 carbon atoms is preferably based on the total amount of the zwitterion-containing acrylic polymer. It is 0 to 30% by mass, more preferably 0 to 26% by mass, and still more preferably 0 to 22% by mass.
• the zwitterion-containing acrylic polymer can be obtained by copolymerizing a zwitterion-containing polymerizable monomer and a (meth) acrylic monomer.
• a polymerizable monomer having a structure capable of introducing a zwitterionic structure is copolymerized with a (meth) acrylic monomer, and a sultone compound is allowed to act on the resulting copolymer to contain zwitterions.
• An acrylic polymer can also be obtained.
• the zwitterion-containing polymerizable monomer used for the synthesis of the zwitterion-containing acrylic polymer refers to a compound having a polymerizable carbon-carbon double bond in the molecule and the polarization structure.
• the (meth) acrylic monomer include the aforementioned (meth) acrylic acid ester, (meth) acrylic acid, (meth) acrylamide, and the like.
• the zwitterion-containing polymerizable monomer can be appropriately determined according to the target zwitterion-containing acrylic polymer.
• a zwitterion-containing acrylic polymer having a repeating unit represented by the above formula (1) can be synthesized using a zwitterion-containing polymerizable monomer represented by the following formula (1a).
• a containing polymerizable monomer can also be used.
• R 1 , R 2 , R 3 , A 1 and m each have the same meaning as described above.
• the method for synthesizing the zwitterion-containing polymerizable monomer represented by the formula (1a) is not particularly limited.
• the zwitterion-containing polymerizable monomer represented by the formula (1a) can be obtained by reacting the corresponding amine compound (1b) and the sultone compound (1c).
• the amine compound (1b) can be produced and obtained by a known method.
• a compound in which the amine moiety (NR 2 R 3 ) is substituted with a structure capable of introducing zwitterions represented by the following formulas (15) to (18) can also be used.
• R 10 to R 24 represent the same meaning as described above, provided that one atom or group of R 10 or R 11 is a radical state that does not exist and represents a bond to A1. Any one atom or group of R 12 to R 16 is a non-existing radical state, and represents a bond to the A1 Any one atom or group of R 17 to R 21 is a non-existing radical state. And represents a bond to the A1. Any one atom or group of R 22 to R 24 does not exist and is in a radical state and represents a bond to the A1.)
• Examples of the sultone compound (1c) include 1,2-ethane sultone, 1,3-propane sultone, 1,4-butane sultone, 2,4-butane sultone, and 1,5-pentane sultone. These are known compounds, and can be produced and obtained by known methods, and commercially available products can also be used.
• the amount of the sultone compound (1c) used is preferably 0.8 to 1.2 equivalents, more preferably 0, relative to the amine compound (1b). .9 to 1.1 equivalents.
• the reaction of the amine compound (1b) and the sultone compound (1c) may be performed without a solvent or in the presence of an inert solvent.
• Inert solvents used include ether solvents such as tetrahydrofuran and diglyme; nitrile solvents such as acetonitrile and propionitrile; ketone solvents such as acetone and methyl ethyl ketone; aromatic hydrocarbon solvents such as toluene and xylene; chloroform and the like And halogenated hydrocarbon solvents.
• the amount used is not particularly limited, but is usually 1 to 100 parts by mass with respect to 1 part by mass of the amine compound (1b).
• the reaction temperature is not particularly limited, but is usually in the range of 0 to 200 ° C, preferably 10 to 100 ° C, more preferably 20 to 60 ° C. Further, the reaction may be carried out under normal pressure (atmospheric pressure), or the reaction may be carried out under pressurized conditions.
• the reaction time is not particularly limited, but is usually 12 to 332 hours, preferably 24 to 168 hours.
• the reaction is preferably carried out in an inert gas atmosphere such as nitrogen gas or argon gas from the viewpoint of preventing the yield from decreasing due to oxidation by oxygen or hydrolysis of the sultone compound (1c) by moisture in the air.
• the progress of the reaction can be confirmed by ordinary analytical means such as gas chromatography, high performance liquid chromatography, thin layer chromatography, NMR, IR and the like.
• the target zwitterion-containing polymerizable monomer is simply purified by a known purification method such as recrystallization or column chromatography. Can be separated.
• a commercially available product may be used as the zwitterion-containing polymerizable monomer.
• a compound in which the amine of the amine compound (1b) is substituted with a structure capable of introducing a zwitterionic structure of the formulas (15) to (18) is the same as in the case of using the amine compound (1b). Then, the zwitterion-containing polymerizable monomer is obtained by reacting with the sultone compound (1c).
• the method for synthesizing the zwitterion-containing acrylic polymer is not particularly limited.
• a zwitterion-containing polymerizable monomer in the presence of a radical polymerization initiator, a zwitterion-containing polymerizable monomer, a (meth) acrylic monomer and, if necessary, a monomer copolymerizable with the zwitterion-containing polymerizable monomer
• a zwitterion-containing acrylic polymer can be synthesized by carrying out a polymerization reaction of a monomer mixture containing.
• Examples of the radical polymerization initiator include organic peroxides and azo compounds.
• organic peroxides include diacyl peroxides such as lauroyl peroxide and benzoyl peroxide; 1,1-bis (t-butylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) 3,3 Peroxyketals such as 1,5-trimethylcyclohexane; peroxydicarbonates such as diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate; t-butylperoxy-2-ethylhexanoate, t- And peroxyesters such as butyl peroxyisobutyrate.
• 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2, 2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis (2-methylpropionate), 4,4′-azobis (4-cyanovaleric acid), 2,2′-azobis (2-hydroxymethylpropionitrile), 2,2′-azobis [2- (2-imidazolin-2-yl) propane ] Etc. are mentioned. These can be used singly or in combination of two or more.
• the amount of the radical polymerization initiator used is usually 0.0001 to 0.1000 mol, preferably 0.001 mol, based on 1 mol of the monomer used in the polymerization reaction (however, in the case of a copolymer, the total amount of monomers). 0005 to 0.0050 mol.
• the conditions for the radical polymerization reaction are not particularly limited as long as the target polymerization reaction proceeds.
• the heating temperature is usually 40 to 150 ° C., and the reaction time can be appropriately set within the range of 1 minute to 24 hours.
• the obtained reaction solution may be used for the preparation of the adhesive composition as it is, or the zwitterion-containing acrylic polymer may be isolated and purified according to a conventional method.
• the zwitterion-containing acrylic polymer is obtained by copolymerizing a polymerizable monomer having a structure capable of introducing a zwitterionic structure with a (meth) acrylic monomer. It can also be obtained by allowing a sultone compound or the like to act on the polymer.
• Examples of structures into which zwitterionic structures can be introduced include amino groups, nitrogen-containing heterocycles, and phosphines.
• the polymerizable monomer having a structure capable of introducing a zwitterionic structure the above-described amine compound (1b) is preferably used.
• the copolymerization of the amine compound (1b) and the (meth) acrylic monomer is performed under the same conditions as the copolymerization of the zwitterion-containing polymerizable monomer and the (meth) acrylic monomer.
• a zwitterion-containing acrylic polymer is obtained by reacting the sultone compound (1c) with a structure into which the zwitterionic structure of the obtained acrylic polymer can be introduced.
• the reaction between the functional group such as an amino group and the sultone compound can be performed under the same conditions as the reaction between the amine compound (1b) and the sultone compound (1c).
• a compound in which the amine moiety (NR 2 R 3 ) of the amine compound (1b) is substituted with a structure capable of introducing the zwitterionic structures of the above formulas (15) to (18) Can also be used.
• the zwitterion-containing acrylic polymer may have a repeating unit derived from a functional group-containing monomer in addition to the above-described repeating unit.
• 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 later 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 zwitterion-containing acrylic polymer. It is possible to
• Examples of the functional group-containing monomer include a hydroxyl group-containing monomer, a carboxy group-containing monomer, an amino group-containing monomer, and an epoxy group-containing monomer. These monomers may be used alone or in combination of two or more. Among these, a hydroxyl group-containing monomer and a carboxy group-containing monomer are preferable, and a hydroxyl group-containing monomer is more preferable.
• hydroxyl group-containing monomer examples include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 3-hydroxybutyl.
• examples thereof include hydroxyalkyl (meth) acrylates such as (meth) acrylate and 4-hydroxybutyl (meth) acrylate; unsaturated alcohols such as vinyl alcohol and allyl alcohol.
• carboxy group-containing monomer examples include ethylenically unsaturated monocarboxylic acids such as crotonic acid; ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid and citraconic acid, and anhydrides thereof; 2-carboxyethyl methacrylate; Is mentioned.
• the ratio of the repeating unit derived from the functional group-containing monomer is 70% by mass or less, preferably 50% by mass or less, based on the total amount of the zwitterion-containing acrylic polymer.
• the zwitterion-containing acrylic polymer can be copolymerized with the above acrylic monomers such as styrene, ⁇ -methylstyrene, vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide and the like.
• acrylic monomers such as styrene, ⁇ -methylstyrene, vinyl toluene, vinyl formate, vinyl acetate, acrylonitrile, acrylamide and the like.
• a repeating unit derived from a monomer may be included.
• the glass transition temperature (Tg) of the obtained zwitterion-containing acrylic polymer is preferably ⁇ 60 to ⁇ 20 ° C., more preferably ⁇ 50 to ⁇ 22 ° C.
• the Tg of the zwitterion-containing acrylic polymer is the loss tangent (tan ⁇ ) in the region of ⁇ 60 to 50 ° C. in the dynamic viscoelasticity measurement at a frequency of 1 Hz of a sample made of the zwitterion-containing acrylic polymer. Refers to the temperature showing the maximum value. If the Tg of the zwitterion-containing acrylic polymer is too low, adhesive residue tends to occur. Moreover, when Tg is too high, the embedding property to the unevenness
• the glass transition temperature of the zwitterion-containing acrylic polymer tends to decrease, for example, when the proportion of the repeating unit derived from alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms is increased.
• the mass average molecular weight (Mw) of the zwitterion-containing acrylic polymer is preferably 10,000 to 300,000, and more preferably 20,000 to 200,000.
• a mass average molecular weight is the value of standard polystyrene conversion measured by the gel permeation chromatography method. If the Mw of the zwitterion-containing acrylic polymer is too low, adhesive residue tends to occur. On the other hand, if Mw is too high, the embeddability in the irregularities on the circuit surface may deteriorate.
• the mass average molecular weight of the zwitterion-containing acrylic polymer tends to decrease, for example, when the radical polymerization initiator used in the production of the zwitterion-containing acrylic polymer is increased. Further, when the polymerization reaction time is lengthened, the mass average molecular weight tends to increase. When the polymerization reaction temperature is increased, the mass average molecular weight tends to decrease.
• the molecular weight distribution (Mw / Mn, Mn is the number average molecular weight) of the zwitterion-containing acrylic polymer is preferably 15 or less, and more preferably 2 to 11. If the molecular weight distribution of the zwitterion-containing acrylic polymer is too wide, adhesive residue tends to occur.
• the molecular weight distribution of the zwitterion-containing acrylic polymer can be narrowed, for example, by preparing the zwitterion-containing acrylic polymer by the living radical method.
• the living radical method for example, a tellurium-containing compound is used as a radical polymerization initiator.
• the molecular weight distribution can be narrowed by polymerization methods such as atom transfer radical polymerization (Atom Transfer Radical Polymerization: ATRP) and reversible addition-fragmentation chain transfer polymerization (Reversible Addition / Fragmentation Chain Transfer Polymerization: RAFT).
• the pressure-sensitive adhesive composition of the present invention contains an acrylic polymer, preferably a zwitterion-containing acrylic polymer.
• an acrylic polymer preferably a zwitterion-containing acrylic polymer.
• the pressure-sensitive adhesive composition may be formed only from the zwitterion-containing acrylic polymer, and may contain components other than the zwitterion-containing acrylic polymer.
• the proportion of the zwitterion-containing acrylic polymer in the adhesive composition of the present invention is preferably 80% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass, based on the total amount of the adhesive composition. % Or more.
• the adhesive composition of the present invention includes, for example, an energy ray-curable compound, a crosslinking agent, a photopolymerization initiator, an adhesive polymer other than a zwitterion-containing acrylic polymer, and other Additives may be included.
• the energy ray curable compound is preferably a monomer or oligomer having an unsaturated group in the molecule and capable of being polymerized and cured by irradiation with energy rays.
• energy ray curable compounds include trimethylolpropane tri (meth) acrylate, pentaerythritol (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 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, Examples include oligomers such as epoxy (meth) acrylate.
• urethane (meth) acrylate oligomers are preferable from the viewpoint of relatively high molecular weight and difficulty in reducing the elastic modulus of the pressure-sensitive adhesive layer.
• the molecular weight (mass average molecular weight in the case of an oligomer) of the energy beam curable compound is preferably 100 to 12000, more preferably 200 to 10,000, still more preferably 400 to 8000, and particularly preferably 600 to 6000.
• the blending ratio is preferably 1 to 99% by mass, more preferably 10 to 85% by mass, and still more preferably 20%, based on the total amount of the adhesive composition. ⁇ 80% by mass.
• the pressure-sensitive adhesive composition may further contain a crosslinking agent.
• a crosslinking agent reacts with the functional group derived from the functional group containing monomer which an acrylic polymer has, for example, and bridge
• crosslinking agent examples include isocyanate-based crosslinking agents such as tolylene diisocyanate, hexamethylene diisocyanate, and adducts thereof; ethylene glycol glycidyl ether, 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane Epoxy crosslinking agents such as hexa [1- (2-methyl) -aziridinyl] triphosphatriazine and the like; chelating crosslinking agents such as aluminum chelates; and the like. These crosslinking agents may be used alone or in combination of two or more.
• an isocyanate-based crosslinking agent is preferable from the viewpoints of increasing cohesive force and improving adhesive force, and availability.
• the blending ratio thereof is preferably 0.01 to 20% by mass, more preferably 0.05, based on the total amount of the pressure-sensitive adhesive composition, from the viewpoint of promoting the crosslinking reaction. To 15% by mass, more preferably 0.1 to 10% by mass.
• an adhesive composition when an adhesive composition is energy-beam curable, it is preferable that an adhesive composition contains a photoinitiator further.
• the curing reaction of the pressure-sensitive adhesive composition can sufficiently proceed even with relatively low energy energy rays such as ultraviolet rays.
• photopolymerization initiator examples include benzoin compounds, acetophenone compounds, acylphosphinoxide compounds, titanocene compounds, thioxanthone compounds, peroxide compounds, and photosensitizers such as amines and quinones.
• 1-hydroxycyclohexyl phenyl ketone 2-hydroxy-2-methyl-1-phenyl-propan-1-one
• benzoin benzoin methyl ether
• benzoin ethyl ether benzoin isopropyl ether
• benzylphenyl Such as sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, 8-chloroanthraquinone, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, etc. It is below.
• photopolymerization initiators may be used alone or in combination of two or more.
• the blending ratio is preferably 0.1 to 10% by mass, more preferably 0.3 to 8.0% by mass, and still more preferably based on the total amount of the energy ray curable component. 0.5 to 5% by mass.
• an adhesive polymer other than the zwitterion-containing acrylic polymer may be blended in the pressure-sensitive adhesive composition.
• an adhesive polymer an acrylic adhesive polymer having no zwitterionic structure, a urethane adhesive polymer, a rubber adhesive polymer, silicone, which is widely used as a main material of an adhesive, is used. System adhesive polymer and the like.
• an acrylic pressure-sensitive adhesive is preferable from the viewpoint of compatibility and affinity.
• the pressure-sensitive adhesive composition may contain other additives as long as the effects of the present invention are not impaired.
• additives include antistatic agents, antioxidants, tackifiers, softeners (plasticizers), fillers, rust inhibitors, pigments, dyes, and the like.
• the adhesive composition may be further diluted with an organic solvent from the viewpoint of improving applicability to a substrate or a release film to form a solution of the adhesive composition.
• organic solvent include methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol and the like.
• the organic solvent used in the synthesis of the adhesive composition may be used as it is, or the organic solvent used in the synthesis so that the solution of the adhesive composition can be uniformly applied.
• One or more organic solvents other than may be added.
• the storage elastic modulus G ′ (23) of the adhesive composition can be controlled by, for example, the monomer composition of the zwitterion-containing acrylic polymer.
• the storage elastic modulus G ′ (23) tends to decrease.
• the content of zwitterion-containing units is increased, it is considered that a relatively hard structure is formed by the association of zwitterion structures in the vicinity of 23 ° C. This is probably because an ionic bond is generated between the negatively charged site of the zwitterionic structure and the positively charged site of the other zwitterionic structure. As a result, the storage elastic modulus G ′ (23) tends to increase.
• the storage elastic modulus G ′ (50) of the adhesive composition can be controlled by, for example, the monomer composition of the zwitterion-containing acrylic polymer.
• the storage elastic modulus G ′ (50) tends to decrease.
• the content of zwitterion-containing units increases, it is considered that a relatively hard structure is formed by association of zwitterion structures in the vicinity of 50 ° C. This is probably because an ionic bond is generated between the negatively charged site of the zwitterionic structure and the positively charged site of the other zwitterionic structure. As a result, the storage elastic modulus G ′ (50) tends to increase.
• Tan ⁇ (60) can be controlled by, for example, the monomer composition of the zwitterion-containing acrylic polymer.
• the content of the zwitterion-containing unit is increased, energy is consumed for cleavage of the association site between the zwitterion structures near 60 ° C., and the loss elastic modulus G ′′ increases.
• the deformation of the pressure-sensitive adhesive layer or the intermediate layer is maintained when the pressure-sensitive adhesive tape is heated, and the contamination and breakage of the circuit surface due to the cutting water can be reduced.
• G ′ (60) / G ′ (23) of the adhesive composition can be controlled by, for example, the monomer composition of the zwitterion-containing acrylic polymer.
• the storage elastic modulus G ′ (23) tends to decrease. Further, as the content of zwitterion-containing units increases, the storage elastic modulus G ′ (23) tends to increase.
• the storage elastic modulus G ′ (60) tends to decrease.
• the content of the zwitterion-containing unit does not significantly affect the storage elastic modulus G ′ (60), but since the association sites of the zwitterionic structures remain partially even near 60 ° C., the storage elastic modulus G ′ (60 ) Is suppressed excessively.
• the temperature at which the maximum value of tan ⁇ appears can be controlled by, for example, the monomer composition of the zwitterion-containing acrylic polymer. As the content of the zwitterion-containing unit increases, the temperature at which the maximum value of tan ⁇ shifts to the high temperature side for both the low temperature side peak and the high temperature side peak. Therefore, by controlling the monomer composition of the zwitterion-containing acrylic polymer, it is possible to achieve good embedding property and shape maintaining property at a desired application temperature.
• the adhesive tape which concerns on this invention has an adhesive layer or an intermediate
• the application of the adhesive tape is not particularly limited, and for example, it can be used as a back grind tape, a dicing tape, a tape for transferring a chip after pickup, and the like.
• the adhesive tape may be cut in advance according to the shape of the object to be attached. For example, when used for back grinding of a semiconductor wafer, it may be cut into the shape of a semiconductor wafer. Moreover, when using as a dicing tape, you may cut according to the shape of a ring frame.
• a pressure-sensitive adhesive tape having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition will be described as a first form, and a pressure-sensitive adhesive tape having an intermediate layer containing the pressure-sensitive adhesive composition will be described as a second form.
• the adhesive tape which concerns on a 1st form contains a base material and an adhesive layer, and the adhesive layer contains the said adhesive composition, It is characterized by the above-mentioned.
• the base material of the pressure-sensitive adhesive tape according to the first embodiment is not particularly limited as long as the pressure-sensitive adhesive tape can function properly in a desired process such as a dicing process or a back-grinding process.
• a resin-based material is mainly used. Consists of film as material.
• Such films include ethylene-copolymer films such as ethylene-vinyl acetate copolymer films, ethylene- (meth) acrylic acid copolymer films, ethylene- (meth) acrylic acid ester copolymer films; Polyethylene film such as density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, high density polyethylene (HDPE) film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, ethylene-norbornene copolymer film Polyolefin film such as norbornene resin film; polyvinyl chloride film such as polyvinyl chloride film and vinyl chloride copolymer film; polyethylene terephthalate film, polybutylene film Polyester film such as terephthalate film; polyurethane film; polyimide film; polystyrene films; polycarbonate films; and fluorine resin film. Further, modified films such as these crosslinked films and ionomer films are also used
• the film constituting the substrate preferably includes at least one of an ethylene copolymer film and a polyolefin film. It is easy to control the mechanical properties of an ethylene copolymer film in a wide range by changing the copolymerization ratio. For this reason, the base material provided with the ethylene-based copolymer film easily satisfies the mechanical properties required as the base material of the pressure-sensitive adhesive tape according to this embodiment. Moreover, since the ethylene-based copolymer film has relatively high adhesion to the pressure-sensitive adhesive layer, peeling at the interface between the base material and the pressure-sensitive adhesive layer hardly occurs when used as a pressure-sensitive adhesive tape.
• some films such as a polyvinyl chloride film include many components that adversely affect the properties as an adhesive tape.
• the plasticizer contained in the film moves from the base material to the pressure-sensitive adhesive layer, and is further distributed on the surface opposite to the side facing the base material of the pressure-sensitive adhesive layer.
• the adhesiveness of the adhesive layer to the workpiece is lowered.
• the ethylene copolymer film and the polyolefin film have a small content of components that adversely affect the properties of the pressure-sensitive adhesive tape, problems such as a decrease in the adhesiveness of the pressure-sensitive adhesive layer to the work hardly occur. That is, the ethylene copolymer film and the polyolefin film are excellent in chemical stability.
• the base material may contain various additives such as a colorant such as a pigment, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler in a film mainly composed of the resin-based material.
• a colorant such as a pigment, a flame retardant, a plasticizer, an antistatic agent, a lubricant, and a filler in a film mainly composed of the resin-based material.
• the pigment include titanium dioxide and carbon black.
• the filler include organic materials such as melamine resin, inorganic materials such as fumed silica, and metal materials such as nickel particles.
• the content of such an additive is not particularly limited, but should be within a range where the substrate exhibits a desired function and does not lose smoothness and flexibility.
• the base material preferably has transparency to predetermined energy rays such as ultraviolet rays and electron beams.
• base material-coated surface the surface of the base material on the side of the pressure-sensitive adhesive layer
• corona treatment to improve the adhesion to the pressure-sensitive adhesive layer, or a primer layer.
• Various coating films may be provided on the surface of the substrate opposite to the substrate deposition surface.
• the thickness of the substrate is not limited as long as the adhesive tape can function properly in a desired process.
• the range is preferably 20 to 450 ⁇ m, more preferably 25 to 400 ⁇ m, and particularly preferably 50 to 350 ⁇ m.
• a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is formed on one side of the substrate.
• the thickness of the pressure-sensitive adhesive layer is preferably 5 to 50 ⁇ m, particularly preferably 7 to 40 ⁇ m, and more preferably 10 to 20 ⁇ m. If the thickness of the pressure-sensitive adhesive layer is less than 5 ⁇ m, there may be a problem that the variation in the adhesiveness of the pressure-sensitive adhesive layer becomes large.
• the adhesive layer only needs to have a thickness capable of embedding irregularities on the surface of the semiconductor wafer. Therefore, when the adhesive tape is attached to the surface of the semiconductor wafer provided with the bumps, the thickness of the adhesive layer only needs to be larger than the height of the bumps.
• the thickness of the pressure-sensitive adhesive layer is preferably 1.0 or more times the height of the bump, more preferably 1.2 to 3 times, and 1.4 to 2 times. More preferably.
• the bump height refers to the maximum bump height provided on the semiconductor wafer.
• the thickness of the pressure-sensitive adhesive layer is specifically preferably 20 to 300 ⁇ m, more preferably 30 to 200 ⁇ m, and further preferably 40 to 150 ⁇ m.
• intermediate layers made of various soft polymers may be provided between the base material and the pressure-sensitive adhesive layer.
• the configuration of the intermediate layer in the first embodiment is arbitrary and is not necessarily provided.
• the intermediate layer is preferably composed of an acrylic soft polymer.
• the thickness of the pressure-sensitive adhesive layer may be smaller than the bump height. That is, it is only necessary that the irregularities on the surface of the semiconductor wafer can be embedded with two layers of an intermediate layer and an adhesive layer.
• the thickness of the intermediate layer is preferably 30 to 500 ⁇ m, more preferably 50 to 300 ⁇ m, and further preferably 80 to 250 ⁇ m.
• the thickness of the pressure-sensitive adhesive layer laminated with the intermediate layer is preferably 5 to 50 ⁇ m, particularly preferably 7 to 40 ⁇ m, and more preferably 10 to 20 ⁇ m.
• the adhesive tape has a release film laminated on the surface opposite to the substrate side of the adhesive layer for the purpose of protecting the adhesive layer until the adhesive layer is applied to the workpiece. Also good.
• the structure of a peeling film is arbitrary and what peeled the plastic film with the peeling agent etc. is illustrated.
• Specific examples of the plastic film include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, and polyolefin films such as polypropylene and polyethylene.
• the release agent silicone-based, fluorine-based, long-chain alkyl-based, and the like can be used, and among these, a silicone-based material that is inexpensive and provides stable performance is preferable.
• the thickness of the release film is not particularly limited, but is usually about 20 to 250 ⁇ m.
• the adhesive tape which concerns on a 2nd form contains a base material, an adhesive layer, and the intermediate
• This type of adhesive tape is particularly preferably used as a back grind tape.
• the base material is the same as that described for the first embodiment, and the surface on the intermediate layer side of the base material (base material attachment surface) may be subjected to the same treatment as described above.
• the total thickness of the adhesive layer and the intermediate layer only needs to have a thickness capable of embedding irregularities on the surface of the semiconductor wafer. Therefore, when the adhesive tape is attached to the surface of the semiconductor wafer provided with the bumps, the total thickness of the adhesive layer and the intermediate layer only needs to be larger than the height of the bumps.
• the total thickness is preferably 1.0 or more times the height of the bump, more preferably 1.2 to 3 times, and even more preferably 1.4 to 2 times.
• the bump height refers to the maximum bump height provided on the semiconductor wafer.
• the total thickness of the pressure-sensitive adhesive layer and the intermediate layer in this case is specifically preferably 20 to 300 ⁇ m, more preferably 30 to 200 ⁇ m, and further preferably 40 to 150 ⁇ m.
• the pressure-sensitive adhesive is not particularly limited as long as it has an appropriate pressure-sensitive adhesive property at room temperature, but preferably has a storage elastic modulus at 23 ° C. of 0.05 to 0.50 MPa.
• a circuit or the like is formed on the surface of the semiconductor wafer and is usually uneven.
• the pressure-sensitive adhesive tape has a storage elastic modulus within the above range, so that when the adhesive surface is applied to a wafer surface with unevenness, the unevenness of the wafer surface and the pressure-sensitive adhesive layer are sufficiently brought into contact with each other, and the adhesiveness of the pressure-sensitive adhesive layer is improved. It is possible to make it work properly. Therefore, it becomes possible to securely fix the adhesive tape to the semiconductor wafer and to appropriately protect the wafer surface during back grinding.
• the storage elastic modulus of the pressure-sensitive adhesive is more preferably 0.10 to 0.35 MPa.
• the storage elastic modulus of an adhesive means the storage elastic modulus before hardening by energy ray irradiation, when an adhesive layer is formed from an energy ray-curable adhesive.
• the thickness of the pressure-sensitive adhesive layer is preferably less than 40 ⁇ m, more preferably 5 to 35 ⁇ m, and even more preferably 10 to 30 ⁇ m.
• the proportion of the low-rigidity portion of the pressure-sensitive adhesive tape can be reduced, so that the grinding accuracy is improved and it becomes easier to prevent chipping of the semiconductor chip that occurs during back surface grinding.
• adhesion of the adhesive to the semiconductor wafer surface is reduced.
• the pressure-sensitive adhesive layer is formed of, for example, an acrylic pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, etc., and an acrylic pressure-sensitive adhesive is preferable.
• an adhesive layer is formed from an energy-beam curable adhesive.
• the pressure-sensitive adhesive layer is formed from an energy-ray curable pressure-sensitive adhesive, so that the elastic modulus at 23 ° C. is set within the above range before curing by irradiation with energy rays, and the peeling force is 1000 mN / 50 mm after curing. It can be easily set to:
• the adhesive layer on the side opposite to the substrate side surface is used.
• a release film may be laminated on the surface.
• Manufacturing method of adhesive tape There is no restriction
• the pressure-sensitive adhesive layer provided on the release film can be bonded to one side of the substrate, and the pressure-sensitive adhesive tape according to the first embodiment in which the release film is attached to the surface of the pressure-sensitive adhesive layer can be produced. What is necessary is just to peel and remove the peeling film stuck on the surface of an adhesive layer suitably before use of an adhesive tape.
• the intermediate layer provided on the release film was bonded to one side of the substrate, and after the release film was peeled off, the adhesive layer provided on the release film was further bonded to the exposed intermediate layer.
• the adhesive tape which concerns on the 2nd form by which the peeling film was stuck on the surface of the agent layer can be manufactured. What is necessary is just to peel and remove the peeling film stuck on the surface of an adhesive layer suitably before use of an adhesive tape.
• the adhesive composition of the present invention is directly applied on the release film by a known application method and heated to volatilize the solvent from the applied film. The method of drying is simple.
• the pressure-sensitive adhesive composition or intermediate layer may be formed by directly applying the pressure-sensitive adhesive composition to one side of the substrate.
• the method for applying the adhesive composition include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.
• the pressure-sensitive adhesive tape of the present invention is preferably used as a dicing tape or a back grind tape.
• the dicing tape can be preferably used for dicing semiconductor wafers, BGA type packages and the like. In particular, it is suitable as a dicing tape for a semiconductor wafer having a large unevenness on the surface in contact with the dicing tape or a BGA type package.
• the dicing method is not particularly limited, and may be blade dicing using a rotating round blade or dicing using laser light.
• the backside of the wafer is ground while affixing an adhesive tape to the circuit surface of a semiconductor wafer having a circuit formed on the surface to protect the circuit surface, thereby obtaining a wafer having a predetermined thickness.
• the semiconductor wafer may be a silicon wafer or a compound semiconductor wafer such as gallium / arsenic. Formation of a circuit on the wafer surface can be performed by various methods including conventionally used methods such as an etching method and a lift-off method. In the semiconductor wafer circuit forming step, a predetermined circuit is formed. Further, bumps may be formed on the surface of the semiconductor wafer.
• the thickness of the wafer before grinding is not particularly limited, but is usually about 500 to 1000 ⁇ m.
• the surface shape of the semiconductor wafer is not particularly limited, but the pressure-sensitive adhesive tape of the present invention is preferably used for protecting the surface of a wafer having bumps formed on the circuit surface.
• the pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer or an intermediate layer exhibiting the above specific elastic behavior, and exhibits viscoelasticity that can sufficiently follow bump irregularities under heating conditions.
• the adhesive tape of the present invention is applied, it is preferably performed in a state where the storage elastic modulus of the adhesive layer or the intermediate layer is lowered. Therefore, it is preferable to apply the adhesive tape to the semiconductor wafer at a temperature of about 40 to 60 ° C. If the temperature at the time of sticking is too high, the intermediate layer and the pressure-sensitive adhesive layer may be excessively softened and fluidized and leak from the side surface of the pressure-sensitive adhesive tape.
• the adhesive layer or the intermediate layer When the adhesive tape is applied under heating, the adhesive layer or the intermediate layer is embedded in the wafer surface on which the bumps are formed, and the unevenness difference is eliminated. Further, by allowing to cool after sticking, the elastic modulus of the pressure-sensitive adhesive layer or the intermediate layer is recovered and the elastic modulus of the pressure-sensitive adhesive layer or the intermediate layer is increased, so that the wafer can be held in a flat state.
• the pressure-sensitive adhesive tape of the present invention has high followability to the surface shape of the wafer, and the pressure-sensitive adhesive layer or intermediate layer is relatively hard in the normal state. It is possible to reduce the end appearance defect.
• the backside grinding is performed by a known method using a grinder, a suction table for fixing the wafer, etc. with the adhesive tape attached. After the back grinding process, a process of removing the crushed layer generated by grinding may be performed.
• the thickness of the semiconductor wafer after back grinding is not particularly limited, but is preferably about 10 to 400 ⁇ m, particularly preferably about 25 to 300 ⁇ m.
• the pressure-sensitive adhesive tape of the present invention it is possible to reliably hold the wafer during backside grinding of the wafer and to prevent cutting water from entering the circuit surface.
• the pressure-sensitive adhesive tape of the present invention is preferably used in the formation of a wafer with bumps by a so-called tip dicing method, specifically, In the process of grinding the back surface of the semiconductor wafer on which the groove is formed on the surface of the semiconductor wafer or the modified region is formed, and dividing the semiconductor wafer into semiconductor chips by the grinding, Forming a modified region in the semiconductor wafer from the front surface or the back surface of the semiconductor wafer, or a groove having a depth of cut shallower than the wafer thickness from the surface of the semiconductor wafer having bumps; Attaching the adhesive tape as a surface protective tape to the circuit forming surface, A semiconductor wafer having an adhesive tape affixed to the surface and formed with the groove or the modified region is ground from the back side, and is separated into a plurality of chips (chip assemblies) starting from the groove or the modified region. , It is preferably used in a method for manufacturing a semiconductor chip.
• the chip is picked up by a predetermined method.
• the chip assembly may be transferred to another adhesive tape (pickup tape), and then chip pickup may be performed.
• the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is energy ray curable, the pressure-sensitive adhesive layer is irradiated with energy rays to cure the pressure-sensitive adhesive layer.
• a pickup tape is affixed to the back side of the chip assembly, and the position and orientation are adjusted so that pickup is possible.
• the ring frame disposed on the outer peripheral side of the chip assembly is also bonded to the pick-up tape, and the outer peripheral edge of the pickup tape is fixed to the ring frame.
• the chip assembly and the ring frame may be bonded to the pickup tape at the same time, or may be bonded at different timings.
• only the adhesive tape is peeled off, and the chip aggregate is transferred onto the pickup tape.
• the pick-up tape is expanded to separate the chips, and individual semiconductor chips on the pick-up tape are picked up and fixed on a substrate or the like to manufacture a semiconductor device.
• the pickup tape is not particularly limited, but is constituted by, for example, an adhesive tape including a base material and an adhesive layer provided on one surface of the base material.
• the adhesive strength of the pickup tape only needs to be greater than the adhesive strength of the back grind tape at the time of peeling. Moreover, when picking up a chip from the pickup tape, it is preferable that the adhesive strength can be reduced. Therefore, as the pickup tape, an energy ray-curable adhesive tape or a foamable easily peelable film is preferably used.
• an adhesive tape can be used instead of the pickup tape.
• An adhesive tape is a laminate of a film adhesive and a release film, a laminate of a dicing tape and a film adhesive, and an adhesive layer and a release film having the functions of both a dicing tape and a die bonding tape.
• the dicing die-bonding tape etc. which become.
• a film adhesive may be bonded to the back side of the separated semiconductor wafer before the pickup tape is applied. When using a film adhesive, the film adhesive may have the same shape as the wafer.
• the adhesive layer may be divided by a laser or an expand, or by a tension at the time of pickup.
• the use as a dicing tape and a back grind tape was outlined about the pressure-sensitive adhesive tape of the present invention
• the use of the pressure-sensitive adhesive tape of the present invention is not particularly limited, and various types of workpieces having irregular surfaces can be retained or temporarily protected. Can be used for
• the measurement method and evaluation method in the present invention are as follows.
• Mw mass average molecular weight
• Mw mass average molecular weight of the zwitterion-containing acrylic polymer was determined by performing gel permeation chromatography (GPC) under the following conditions.
• GPC gel permeation chromatography
• the adhesive tapes produced in Examples 1 to 4 and Comparative Examples 1 and 2 were cut into strips having a width of 25 mm and affixed to the mirror-polished surface of a silicon wafer (diameter 6 inches) with one side mirror-polished.
• the adhesive tape was attached by reciprocating once with a 2.5 kg roller at 23 ° C. and 50% RH (relative humidity). After sticking the adhesive tape, it was allowed to stand for 20 minutes, and the adhesive tape was peeled off. Peeling was performed with a tensile tester (Orientec, product name “Tensilon”) at a peeling speed of 300 mm / min and a peeling angle of 180 °. After peeling, the wafer surface was visually observed to confirm the presence of adhesive residue.
• the adhesive residue was determined according to the following criteria. A: No visible adhesive residue B: Visual adhesive residue remaining
• Dicing property was evaluated by dicing the silicon wafer using the adhesive tapes prepared in Examples 1 to 4 and Comparative Examples 1 and 2 and counting the number of scattered chips.
• a tape laminator manufactured by FUJiPLA, product name “LPD3226Meister6” was attached to the mirror-polished surface of a silicon wafer (diameter 6 inches, thickness 200 ⁇ m) with one side mirror-polished.
• the pasting conditions were a temperature of 23 ° C. and a pasting speed of 0.4 m / min. With the adhesive tape attached to the silicon wafer, the silicon wafer was diced to a size of 10 mm ⁇ 10 mm to form a chip.
• a dicing machine manufactured by Disco Corporation, product name “DFD-6361”
• the blade rotation speed was 4500 rpm
• the cutting speed was 50 mm / sec.
• the number of peeled chips was counted.
• the chip (triangular chip) at the edge of the wafer that is not a product is not included in the number of scattered parts. Evaluation was performed on the total number of square chips. Dicing property was determined according to the following criteria. A: Chip scattering number less than 3 B: Chip scattering number 3 to less than 10 C: Chip scattering number 10 or more
• the temperature of the laminating table of the apparatus was set to 23 ° C.
• the laminating roller was set to 60 ° C.
• the roller pressure was set to 0.3 MPa
• the pasting speed was set to 10 mm / second.
• the diameter of a circular void generated around the bump from the substrate side was measured using a digital microscope (manufactured by Keyence Corporation, product name “VHX-1000”), and the embedding property was evaluated according to the following criteria. The smaller the gap diameter, the higher the embedding in the bump.
• B Diameter of void is not less than 90 ⁇ m and less than 100 ⁇ m
• C Diameter of void is not less than 100 ⁇ m
• [Zwitterion-containing acrylic polymer 1] In a reaction vessel equipped with a stirrer, 93 parts by mass of n-butyl acrylate (BA), 5 parts by mass of dimethylaminoethyl acrylate (DMAEA), 2 parts by mass of 2-hydroxyethyl acrylate (HEA), and an initiator Azobisisobutyronitrile (AIBN) and 180 parts by mass of ethyl acetate as a solvent were charged, and nitrogen was introduced for 30 minutes with stirring.
• BA n-butyl acrylate
• DAEA dimethylaminoethyl acrylate
• HOA 2-hydroxyethyl acrylate
• AIBN Azobisisobutyronitrile
• Tg Glass transition temperature (Tg) ⁇ 30 ° C., mass average molecular weight (Mw) 100300, molecular weight distribution (Mw / Mn) 10.4, ⁇ 30 ° C.
• Mw mass average molecular weight
• Mw / Mn molecular weight distribution
• Methyl ethyl ketone was added and diluted so that the resulting prepolymer solution 2 had a solid content of 30%.
• 2.33 parts by mass of propane sultone was slowly added dropwise at room temperature, followed by stirring for 3 hours.
• the reaction system was raised to 60 ° C., and further reacted for 48 hours.
• Tg ⁇ 24 ° C., Mw 165000, Mw / Mn 10.3, ⁇ 24 ° C. and 50 ° C. have tan ⁇ maximum peaks, and unit containing zwitter ions
• a zwitterion-containing acrylic polymer 2 having a ratio of 3% by mass was obtained.
• Methyl ethyl ketone was added and diluted so that the resulting prepolymer solution 3 had a solid content of 30%.
• 2.33 parts by mass of propane sultone was slowly added dropwise at room temperature, followed by stirring for 3 hours.
• the reaction system was raised to 60 ° C and then reacted for another 48 hours.
• a zwitterion-containing acrylic polymer 3 having a ratio of 5% by mass was obtained.
• Methyl ethyl ketone was added and diluted so that the resulting prepolymer solution 4 had a solid content of 30%.
• 2.33 parts by mass of propane sultone was slowly added dropwise at room temperature, followed by stirring for 3 hours.
• the reaction system was raised to 60 ° C., and further reacted for 48 hours.
• Tg-33 ° C., Mw 142700, Mw / Mn 10.9, ⁇ 30 ° C. and 60 ° C. had maximum peaks of tan ⁇ , unit containing zwitter ions
• a zwitterion-containing acrylic polymer 4 having a ratio of 4% by mass was obtained.
• Adhesive polymer A Acrylic copolymer resin solution (adhesive) comprising 86 parts by weight of butyl acrylate (BA), 8 parts by weight of methyl methacrylate (MMA), 1 part by weight of acrylic acid (AA), and 5 parts by weight of 2-hydroxyethyl acrylate (2HEA) Agent main component, mass average molecular weight 720000, solid content 35.0% by mass).
• Adhesive polymer B Acrylic copolymer consisting of 59.5 parts by weight of 2-ethylhexyl acrylate (2EHA), 30 parts by weight of vinyl acetate (Vac), 0.5 parts by weight of acrylic acid (AA), and 10 parts by weight of 2-hydroxyethyl acrylate (2HEA)
• EHA 2-ethylhexyl acrylate
• Vac vinyl acetate
• AA acrylic acid
• HOA 2-hydroxyethyl acrylate
• a solution of the combined resin (adhesive main component, mass average molecular weight 700,000, solid content 35.0% by mass) was prepared.
• 1.9 parts by mass (solid content) of a polyisocyanate compound product name “BHS-8515”, manufactured by Toyochem Co., Ltd., solid content 37.5% by mass
• composition C for intermediate layer An acrylic ester copolymer having a mass average molecular weight of 600,000 consisting of 91 parts by mass of butyl acrylate and 9 parts by mass of acrylic acid was prepared. Separately from this, an acrylic copolymer comprising 62 parts by mass of n-butyl acrylate (BA), 10 parts by mass of methyl methacrylate (MMA), and 28 parts by mass of 2-hydroxyethyl acrylate (2HEA), 2-isocyanatoethyl methacrylate (product name “Karenz MOI” (registered trademark), manufactured by Showa Denko KK) was added to 100 mol% of 2HEA so that the addition ratio was 80 mol% (solid content 35. 0% by mass) was obtained. With respect to 100 parts by mass (solid content) of the above acrylate copolymer, the resin solution was mixed at a ratio of 10 parts by mass based on the solid content, to obtain an intermediate layer composition C.
• BA n-butyl acrylate
• composition D for Intermediate Layer An acrylic ester copolymer having a mass average molecular weight of 600,000 consisting of 91 parts by mass of butyl acrylate and 9 parts by mass of acrylic acid was prepared. 2 parts by mass (solid content) of 2 to 3 functional urethane acrylate oligomer (product name “PU-5”, manufactured by Dainichi Seika) is added to 100 parts by mass (solid content) of the acrylate copolymer. A layer composition D was obtained.
• the elastic moduli of the zwitterion-containing acrylic polymers 1 to 4, the adhesive polymers A and B, and the adhesive compositions C and D were measured.
• the ratio of storage modulus G ′ (60), G ′ (60) / G ′ (23) is shown in the table below.
• An adhesive tape having an adhesive layer composed of zwitterion-containing acrylic polymers 1 to 4 and adhesive polymers A and B was prepared. Zwitterion-containing acrylic polymers 1 to 4 and adhesive polymer A or B are applied to a polyethylene terephthalate (PET) release film (product name “SP-PET 381031”, thickness 38 ⁇ m, manufactured by Lintec) and dried. A pressure-sensitive adhesive layer having a thickness of 20 ⁇ m was obtained. The pressure-sensitive adhesive layer and the substrate were bonded together to produce a pressure-sensitive adhesive tape.
• PET polyethylene terephthalate
• Zwitterion-containing acrylic polymers 1 to 4 and intermediate layer composition C or D are applied to a polyethylene terephthalate (PET) release film (product name “SP-PET 381031”, thickness 38 ⁇ m, manufactured by Lintec) and dried. To obtain a resin layer having a thickness of 45 ⁇ m. A resin layer having a thickness of 90 ⁇ m was formed by pasting together a similarly prepared resin layer having a thickness of 45 ⁇ m. The resin layer and the base material were bonded together to produce a laminate of the resin layer and the base material. This resin layer will later become an intermediate layer.
• PET polyethylene terephthalate
• the polymer as the main component of the adhesive composition has a polymer in which a site having different viscoelastic behavior depending on temperature, that is, a repeating unit containing a zwitterionic structure. Polymer. This makes it easy to control the fluidity of the adhesive layer (or intermediate layer) during sticking and storage, follows the uneven surface of the workpiece during sticking, and prevents the adhesive composition from leaking during storage. Tape is provided.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Adhesive Tapes (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Laminated Bodies (AREA)

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• 2019
  • 2019-03-26 JP JP2020510851A patent/JPWO2019189070A1/ja active Pending
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