CN115368841A - Adhesive tape, dicing die-bonding film, and method for manufacturing semiconductor device - Google Patents

Adhesive tape, dicing die-bonding film, and method for manufacturing semiconductor device Download PDF

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Publication number
CN115368841A
CN115368841A CN202210534957.9A CN202210534957A CN115368841A CN 115368841 A CN115368841 A CN 115368841A CN 202210534957 A CN202210534957 A CN 202210534957A CN 115368841 A CN115368841 A CN 115368841A
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Prior art keywords
meth
die
adhesive layer
dicing
acrylate
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Chinese (zh)
Inventor
福井章洋
杉村敏正
角野雅俊
大西谦司
木村雄大
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Nitto Denko Corp
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Nitto Denko Corp
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    • 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]
    • C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • C09J7/385—Acrylic 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
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/12—Esters of monohydric alcohols or phenols
    • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/12—Esters of monohydric alcohols or phenols
    • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C08F220/1809—C9-(meth)acrylate
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
    • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
    • C08F220/10—Esters
    • C08F220/12—Esters of monohydric alcohols or phenols
    • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
    • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
    • C08F220/1812—C12-(meth)acrylate, e.g. lauryl (meth)acrylate
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C09J133/062—Copolymers with monomers not covered by C09J133/06
    • C09J133/066—Copolymers with monomers not covered by C09J133/06 containing -OH groups
    • 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
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H01L21/52—Mounting semiconductor bodies in containers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H01L21/6835—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support
    • H01L21/6836—Wafer tapes, e.g. grinding or dicing support tapes
    • 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
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
    • H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2203/00—Applications of adhesives in processes or use of adhesives in the form of films or foils
    • C09J2203/326—Applications of adhesives in processes or use of adhesives in the form of films or foils for bonding electronic components such as wafers, chips or semiconductors
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/10—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet
    • C09J2301/12—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers
    • C09J2301/122—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive tape or sheet by the arrangement of layers the adhesive layer being present only on one side of the carrier, e.g. single-sided adhesive tape
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/20—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself
    • C09J2301/208—Additional features of adhesives in the form of films or foils characterized by the structural features of the adhesive itself the adhesive layer being constituted by at least two or more adjacent or superposed adhesive layers, e.g. multilayer adhesive
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature
    • 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
    • C09J2433/00—Presence of (meth)acrylic polymer
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2221/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof covered by H01L21/00
    • H01L2221/67—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere
    • H01L2221/683—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H01L2221/68304—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support
    • H01L2221/68327—Apparatus for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components; Apparatus not specifically provided for elsewhere for supporting or gripping using temporarily an auxiliary support used during dicing or grinding

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Computer Hardware Design (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Adhesive Tapes (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Dicing (AREA)

Abstract

The invention relates to an adhesive tape, a dicing die-bonding film, and a method for manufacturing a semiconductor device. Provided is an adhesive tape or the like for dicing a die-bonding film having the adhesive layer, the adhesive tape including: the pressure-sensitive adhesive tape comprises an acrylic copolymer having, as monomer units, at least an aliphatic alkyl (meth) acrylate unit having 12 or more carbon atoms in the alkyl moiety and a crosslinkable group-containing (meth) acrylate unit in the molecule, wherein the acrylic copolymer contains the aliphatic alkyl (meth) acrylate unit in an amount of 10 to 85 mol% and the crosslinkable group-containing (meth) acrylate unit in an amount of 15 to 35 mol%.

Description

Adhesive tape, dicing die-bonding film, and method for manufacturing semiconductor device
Technical Field
The present invention relates to a dicing die-bonding film used in, for example, manufacturing a semiconductor device, and an adhesive tape provided in the dicing die-bonding film. The present invention also relates to a method for manufacturing a semiconductor device, in which the dicing die-bonding film is used to manufacture a semiconductor device.
Background
Conventionally, dicing die-bonding films used for manufacturing semiconductor devices are known. Such a dicing die-bonding film includes, for example: a dicing tape, and a die bonding sheet laminated on the dicing tape and bonded to a wafer. The dicing tape has a base material layer and an adhesive tape (adhesive layer) in contact with the die-bonding sheet. Such a dicing die-bonding film is used in the manufacture of a semiconductor device, for example, as described below.
A method of manufacturing a semiconductor device generally includes: the method includes a pre-process of forming a circuit surface on one surface of a wafer by using a highly integrated electronic circuit, and a post-process of cutting out chips from the wafer on which the circuit surface is formed and assembling the chips.
The post-process includes, for example: a dicing step of forming a fragile portion for cutting the wafer into small chips (die) on the wafer; a mounting step of attaching a surface of the wafer opposite to the circuit surface to a die bonding sheet to fix the wafer to a dicing tape; an expanding step of cutting the wafer on which the fragile portion is formed together with the chip bonding sheet to expand the interval between the chips; a pickup step of taking out the chip (die) with the die bonding sheet attached thereto by peeling the die bonding sheet and an adhesive tape (adhesive layer); a die bonding step of bonding a die (die) having a die bonding sheet attached thereto to an adherend via the die bonding sheet; and a curing step of performing a thermosetting treatment on the die bonding sheet bonded to the adherend. The semiconductor device is manufactured through these steps, for example.
In the above-described method for manufacturing a semiconductor device, for example, in the above-described pickup step, a dicing die-bonding film in which the gel fraction of the pressure-sensitive adhesive layer before heating and the gel fraction after heating are respectively defined is known in order to improve the peelability when the die-bonding sheet is peeled together with the chip (for example, patent document 1).
In detail, in the dicing die-bonding film described in patent document 1, the adhesive layer is formed of an adhesive composition containing a base polymer and a thermal crosslinking agent, and the adhesive layer has a gel fraction before heating of less than 90% by weight and a gel fraction after heating of 90% by weight or more.
With the dicing die-bonding film described in patent document 1, the die-bonding sheet can be easily peeled off from the cured adhesive layer, and the chip can be picked up together with the die-bonding sheet.
Documents of the prior art
Patent literature
Patent document 1: japanese laid-open patent publication No. 2009-135377
Disclosure of Invention
Problems to be solved by the invention
However, it is said that a sufficient study has not been made on an adhesive tape (adhesive layer) that can exhibit good pickup properties and a dicing die bonding film provided with the adhesive tape.
Therefore, an object of the present invention is to provide an adhesive tape having excellent pickup properties, and a dicing die bonding film provided with the adhesive tape. Another object of the present invention is to provide a method for manufacturing a semiconductor device that can exhibit good pickup properties.
Means for solving the problems
In order to solve the above problems, an adhesive tape according to the present invention is used as the adhesive layer of a dicing die-bonding film, the dicing die-bonding film including: an adhesive layer, and a die bonding sheet superposed on the adhesive layer,
the adhesive tape comprises an acrylic copolymer having, as monomer units in a molecule, at least: an aliphatic alkyl (meth) acrylate unit having an alkyl moiety with 12 or more carbon atoms and a crosslinkable group-containing (meth) acrylate unit,
the acrylic copolymer contains 10 to 85 mol% of the aliphatic alkyl (meth) acrylate unit and 15 to 35 mol% of the crosslinkable group-containing (meth) acrylate unit.
The dicing die-bonding film of the present invention is characterized by comprising:
a dicing tape having a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive tape and a base material layer superposed on the pressure-sensitive adhesive layer; and
and a die bonding sheet overlapping the adhesive layer of the dicing tape.
Further, a method for manufacturing a semiconductor device according to the present invention includes:
a cutting step of cutting the wafer on which the circuit surface is formed into chips; and
and a pickup step of peeling the die bonding sheet of the dicing die bonding film attached to the adhesive tape from the adhesive tape together with the die.
Drawings
Fig. 1 is a sectional view of a dicing die-bonding film according to the present embodiment cut in a thickness direction.
Fig. 2A is a sectional view schematically showing a state of an stealth dicing step in a method of manufacturing a semiconductor device.
Fig. 2B is a sectional view schematically showing a state of an stealth dicing step in the method for manufacturing a semiconductor device.
Fig. 2C is a sectional view schematically showing a state of a stealth dicing step in the method for manufacturing a semiconductor device.
Fig. 2D is a sectional view schematically showing a state of a back grinding step in the method for manufacturing a semiconductor device.
Fig. 3A is a sectional view schematically showing a state of a mounting process in a method for manufacturing a semiconductor device.
Fig. 3B is a sectional view schematically showing a state of a mounting process in the method of manufacturing a semiconductor device.
Fig. 4A is a sectional view schematically showing a state of an expanding process at a low temperature in the method for manufacturing a semiconductor device.
Fig. 4B is a sectional view schematically showing a state of an expanding process at a low temperature in the method for manufacturing a semiconductor device.
Fig. 4C is a sectional view schematically showing a state of an expanding process at a low temperature in the method for manufacturing a semiconductor device.
Fig. 5A is a sectional view schematically showing a state of an expanding process at normal temperature in the method for manufacturing a semiconductor device.
Fig. 5B is a sectional view schematically showing a state of an expanding process at normal temperature in the method for manufacturing a semiconductor device.
Fig. 6 is a sectional view schematically showing a state of a pickup step in the method of manufacturing a semiconductor device.
Fig. 7 is a sectional view schematically showing a state of a die bonding step in the method for manufacturing a semiconductor device.
Fig. 8 is a sectional view schematically showing a state of a wire bonding step in the method for manufacturing a semiconductor device.
Fig. 9 is a sectional view schematically showing a state of a sealing step in a method for manufacturing a semiconductor device.
Fig. 10 is a schematic cross-sectional view showing an example of a state in which the semiconductor chip and the die bonding sheet are warped.
Fig. 11 shows an example of an observation image when the cross section of the pressure-sensitive adhesive layer is observed with an electron microscope (the left side is a schematic view, and the right side is a photograph).
Fig. 12 shows another example of an observation image when the cross section of the pressure-sensitive adhesive layer is observed with an electron microscope (the left side is a schematic view, and the right side is a photograph).
Description of the reference numerals
1: cutting the die bonding film,
10: a chip bonding sheet,
20: a cutting belt,
21: substrate layer, 22: adhesive layer (adhesive tape).
Detailed Description
An embodiment of the adhesive tape and the dicing die-bonding film provided with the adhesive tape of the present invention will be described below with reference to the drawings. It should be noted that the drawings in the drawings are schematic views and are not necessarily the same as the aspect ratio in the real object.
As shown in fig. 1, the dicing die-bonding film 1 of the present embodiment includes: a dicing tape 20, and a die bond sheet 10 laminated on an adhesive layer 22 (i.e., an adhesive tape (described later)) of the dicing tape 20 and bonded to a semiconductor wafer.
The adhesive tape, the dicing die-bonding film, and the method for manufacturing a semiconductor device described later according to the present embodiment can exhibit good pickup properties.
In the present embodiment, the adhesive tape is used for the adhesive layer 22 of the dicing tape 20. Therefore, the detailed description of the pressure-sensitive adhesive tape will be described below with reference to the pressure-sensitive adhesive layer 22.
In the dicing die-bonding film 1 of the present embodiment, the adhesive layer 22 is cured by irradiation with active energy rays (for example, ultraviolet rays) at the time of use. Specifically, in a state where the die bonding sheet 10 having one surface to which the semiconductor wafer is bonded and the pressure-sensitive adhesive layer 22 bonded to the other surface of the die bonding sheet 10 are laminated, at least the pressure-sensitive adhesive layer 22 is irradiated with ultraviolet rays or the like. For example, ultraviolet rays or the like are irradiated from the side where the base material layer 21 is disposed, and the ultraviolet rays or the like passing through the base material layer 21 reach the pressure-sensitive adhesive layer 22. The adhesive layer 22 is cured by irradiation with ultraviolet rays or the like.
Since the adhesive layer 22 is cured after irradiation, the adhesive force of the adhesive layer 22 can be reduced, and thus the die bond sheet 10 (in a state where the semiconductor wafer is bonded) can be peeled off from the adhesive layer 22 relatively easily after irradiation. The die bonding sheet 10 is bonded to an adherend such as a circuit board or a semiconductor chip in the manufacture of a semiconductor device.
< dicing tape for dicing die-bonding film >
The dicing tape 20 is usually a long sheet, and is stored in a wound state until use. The dicing die-bonding film 1 of the present embodiment is used by being bonded to an annular frame having an inner diameter slightly larger than that of a silicon wafer to be subjected to dicing.
The dicing tape 20 includes: a base layer 21, and a pressure-sensitive adhesive layer 22 (pressure-sensitive adhesive tape) superposed on the base layer 21.
In the present embodiment, the adhesive layer 22 includes, for example: an acrylic copolymer, an isocyanate compound and a polymerization initiator.
The adhesive layer 22 may have a thickness of 5 μm or more and 40 μm or less. The shape and size of the pressure-sensitive adhesive layer 22 are generally the same as those of the base material layer 21.
The pressure-sensitive adhesive layer 22 contains an acrylic copolymer having, as monomer units, an aliphatic alkyl (meth) acrylate unit having 12 or more carbon atoms and at least an alkyl moiety in the molecule, and a crosslinkable group-containing (meth) acrylate unit,
the acrylic copolymer contains 10 to 85 mol% of the aliphatic alkyl (meth) acrylate unit and 15 to 35 mol% of the crosslinkable group-containing (meth) acrylate unit.
In the present specification, the expression "(meth) acrylate" means at least one of methacrylate and acrylate. The same applies to the term "(meth) acrylic acid".
The acrylic copolymer has at least the above aliphatic alkyl (meth) acrylate unit and the above crosslinkable group-containing (meth) acrylate unit as monomer units in the molecule. The monomer unit is a unit constituting the main chain of the acrylic copolymer. In other words, the monomer unit is derived from a monomer used to polymerize the acrylic copolymer. Each side chain in the above-mentioned acrylic copolymer is contained in each monomer unit constituting the main chain.
The above aliphatic alkyl (meth) acrylate unit is derived from an aliphatic alkyl (meth) acrylate monomer. In other words, the molecular structure of the aliphatic alkyl (meth) acrylate monomer after polymerization is an aliphatic alkyl (meth) acrylate unit. The expression "alkyl" denotes a hydrocarbon moiety ester-bonded to (meth) acrylic acid.
The alkyl moiety (hydrocarbon) in the aliphatic alkyl (meth) acrylate unit may be a saturated hydrocarbon or an unsaturated hydrocarbon.
The alkyl moiety (hydrocarbon) in the aliphatic alkyl (meth) acrylate unit may be a straight-chain hydrocarbon, a branched-chain hydrocarbon, or a cyclic structure.
The number of carbon atoms of the alkyl moiety (hydrocarbon) in the aliphatic alkyl (meth) acrylate unit may be 22 or less, 18 or less, or 14 or less.
In the above-mentioned acrylic copolymer, the aliphatic alkyl (meth) acrylate unit preferably includes an aliphatic alkyl (meth) acrylate unit in which the alkyl moiety is a saturated hydrocarbon, more preferably includes an aliphatic saturated alkyl (meth) acrylate unit in which the alkyl moiety is a saturated hydrocarbon and is a hydrocarbon having 10 or more and 14 or less carbon atoms, and still more preferably includes a linear aliphatic saturated alkyl (meth) acrylate unit in which the alkyl moiety is a linear saturated hydrocarbon and is a hydrocarbon having 10 or more and 14 or less carbon atoms.
The aliphatic alkyl (meth) acrylate unit preferably does not contain a benzene ring or an ether bond (-CH) in the molecule 2 -O-CH 2 -, -OH group, and-COOH group. In the aliphatic alkyl (meth) acrylate unit, the alkyl moiety does not contain atoms other than C and H, and may be a saturated straight-chain hydrocarbon or a saturated branched-chain hydrocarbon composed of carbon atoms of 10 to 18 carbon atoms.
By including the aliphatic alkyl (meth) acrylate unit in the acrylic copolymer, more favorable pickup properties can be exhibited.
Examples of the structure of the alkyl portion (hydrocarbon portion) of the aliphatic alkyl (meth) acrylate unit include a saturated linear alkyl structure having 12 or more carbon atoms.
Specifically, examples of the aliphatic alkyl (meth) acrylate unit include units such as lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, stearyl (meth) acrylate, and behenyl (meth) acrylate.
The alkyl portion (hydrocarbon portion) of the aliphatic alkyl (meth) acrylate unit may be a saturated branched chain. For example, it may be an isostearyl (meth) acrylate unit.
In the acrylic copolymer, the aliphatic alkyl (meth) acrylate unit may include 1 type or may include 2 or more types.
The acrylic copolymer may further contain a saturated branched alkyl (meth) acrylate unit having 7 to 11 carbon atoms in the alkyl moiety. This can exhibit more excellent pickup performance.
The structure of the alkyl moiety (hydrocarbon moiety) of the saturated branched alkyl (meth) acrylate unit may be a saturated branched alkyl structure, and may be an iso (iso) structure, a secondary (sec) structure, a neo (neo) structure, or a tertiary (tert) structure.
Specific examples of the saturated branched alkyl (meth) acrylate unit include units of isoheptyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Among these, at least one of the isononyl (meth) acrylate unit and the 2-ethylhexyl (meth) acrylate unit is preferable because good pickup properties can be exhibited and the so-called chip floating in the above-mentioned expanding step can be suppressed.
The acrylic copolymer preferably contains a lauryl (meth) acrylate unit and at least one of a 2-ethylhexyl (meth) acrylate unit and an isononyl (meth) acrylate unit. This can exhibit more excellent pickup performance.
The crosslinkable group-containing (meth) acrylate unit contained in the acrylic copolymer has a hydroxyl group capable of forming a urethane bond by a urethanation reaction or a polymerizable group capable of polymerizing by a radical reaction. More specifically, the crosslinkable group-containing (meth) acrylate unit has either an unreacted hydroxyl group or a radically polymerizable carbon-carbon double bond as a polymerizable group. In other words, a part of the crosslinkable group-containing (meth) acrylate unit has unreacted hydroxyl groups, and the other part (all others) has no hydroxyl groups but has radically polymerizable carbon-carbon double bonds.
The acrylic copolymer has, as the crosslinkable group-containing (meth) acrylate unit, a hydroxyl group-containing (meth) acrylate unit in which a hydroxyl group is bonded to an alkyl group having 4 or less carbon atoms. When the pressure-sensitive adhesive layer 22 contains an isocyanate compound, the isocyanate group of the isocyanate compound can easily react with the hydroxyl group of the hydroxyl group-containing (meth) acrylate unit.
By allowing the acrylic copolymer having a hydroxyl group-containing (meth) acrylate unit and the isocyanate compound to coexist in advance in the pressure-sensitive adhesive layer 22, the pressure-sensitive adhesive layer 22 can be appropriately cured. Therefore, the acrylic copolymer can be sufficiently gelled. Therefore, the adhesive layer 22 can maintain the shape and exert the adhesive property.
In the present embodiment, the hydroxyl group-containing (meth) acrylate unit is a hydroxyl group-containing C2 to C4 alkyl (meth) acrylate unit in which an OH group is bonded to an alkyl moiety having 2 to 4 carbon atoms. The expression "C2 to C4 alkyl group" denotes a hydrocarbon moiety ester-bonded to (meth) acrylic acid and the carbon number thereof. In other words, the hydroxyl group-containing C2 to C4 alkyl (meth) acrylic monomer means a monomer in which (meth) acrylic acid is ester-bonded to an alcohol having 2 to 4 carbon atoms (usually 2-membered alcohol).
The hydrocarbon portion of the C2-C4 alkyl group is typically a saturated hydrocarbon. For example, the hydrocarbon moiety of the C2 to C4 alkyl group is a straight-chain saturated hydrocarbon or a branched-chain saturated hydrocarbon. The hydrocarbon moiety of the C2-C4 alkyl group preferably does not contain a polar group containing oxygen (O), nitrogen (N), or the like.
Examples of the hydroxyl group-containing C2-C4 alkyl (meth) acrylate unit include units of hydroxybutyl (meth) acrylate such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxy-n-butyl (meth) acrylate, and hydroxyisobutyl (meth) acrylate. The hydroxyl group (-OH group) may be bonded to the carbon (C) at the end of the hydrocarbon moiety, or may be bonded to a carbon (C) other than the end of the hydrocarbon moiety.
In the present embodiment, the acrylic copolymer preferably contains, as the crosslinkable group-containing (meth) acrylate unit, a polymerizable (meth) acrylate unit having a radically polymerizable carbon-carbon double bond (polymerizable unsaturated double bond) in a side chain.
The polymerizable (meth) acrylate unit specifically has the following molecular structure: a molecular structure in which an isocyanate group of an isocyanate group-containing (meth) acrylic monomer is urethane-bonded to a hydroxyl group in the hydroxyl group-containing (meth) acrylate unit.
The acrylic copolymer contains a radical polymerizable carbon-carbon double bond of a polymerizable (meth) acrylate unit, and the pressure-sensitive adhesive layer 22 can be more sufficiently cured by irradiation with an active energy ray (ultraviolet ray or the like) before the pickup step. For example, the photopolymerization initiator generates radicals by irradiation with active energy rays such as ultraviolet rays, and the acrylic copolymers are subjected to a crosslinking reaction by the action of the radicals. This can reduce the adhesive strength of the pressure-sensitive adhesive layer 22 before irradiation after irradiation. Further, the die bond sheet 10 can be favorably peeled from the adhesive layer 22.
As the active energy ray, ultraviolet rays, radiation rays, and electron beams are used.
The polymerizable (meth) acrylate unit may be prepared by a urethanation reaction after the polymerization reaction of the acrylic copolymer. For example, after copolymerization of an alkyl (meth) acrylate monomer and a hydroxyl group-containing (meth) acrylic monomer, a hydroxyl group in a part of the hydroxyl group-containing (meth) acrylate unit and an isocyanate group of an isocyanate group-containing polymerizable monomer are subjected to a urethane-forming reaction, whereby a polymerizable (meth) acrylate unit can be obtained.
The isocyanate group-containing (meth) acrylic monomer described above preferably has 1 isocyanate group and 1 (meth) acryloyl group in the molecule. Examples of the monomer include 2-methacryloyloxyethyl isocyanate.
In the present embodiment, the acrylic copolymer may contain a monomer unit other than the monomer unit. For example, units such as (meth) acryloylmorpholine, N-vinyl-2-pyrrolidone, or acrylonitrile may be contained.
In the acrylic copolymer contained in the pressure-sensitive adhesive layer 22, the above-mentioned units (structural units) may be replaced by 1 H-NMR、 13 NMR analysis such as C-NMR, thermal decomposition GC/MS analysis, infrared spectroscopy, and the like. The molar ratio of the unit in the acrylic copolymer is usually calculated from the amount of blending (amount charged) in the polymerization of the acrylic copolymer.
As described above, the acrylic copolymer contains the aliphatic alkyl (meth) acrylate unit in an amount of 10 to 85 mol% in the monomer unit. The acrylic copolymer preferably contains 15 mol% or more, more preferably 30 mol% or more of the aliphatic alkyl (meth) acrylate unit. The acrylic copolymer preferably contains 80 mol% or less, more preferably 50 mol% or less, and still more preferably 40 mol% or less of the aliphatic alkyl (meth) acrylate unit. This can more sufficiently maintain the adhesive strength between the die bond sheet 10 and the adhesive layer 22 before curing, and can more sufficiently suppress chip lifting, and can further improve the releasability between the die bond sheet 10 and the adhesive layer 22 after curing, and can exhibit more favorable pickup properties.
As described above, the acrylic copolymer contains a crosslinkable group-containing (meth) acrylate unit in an amount of 15 to 35 mol% based on the monomer unit. In other words, the ratio of the total amount of the hydroxyl group-containing (meth) acrylate unit having a hydroxyl group in the molecule and the polymerizable (meth) acrylate unit is 15 mol% or more and 35 mol% or less in the monomer unit.
The acrylic copolymer preferably contains 15 mol% or more, more preferably 20 mol% or more of the hydroxyl group-containing (meth) acrylate unit having a hydroxyl group in the molecule. The acrylic copolymer preferably contains 35 mol% or less, more preferably 30 mol% or less, of the hydroxyl group-containing (meth) acrylate unit having a hydroxyl group in the molecule. This can more sufficiently maintain the adhesive strength between the die bond sheet 10 and the adhesive layer 22 before curing, and can more sufficiently suppress chip lifting, and can further improve the releasability between the die bond sheet 10 and the adhesive layer 22 after curing, and can exhibit more favorable pickup properties.
The acrylic copolymer preferably contains 5 to 35 mol% of polymerizable (meth) acrylate units having a radically polymerizable carbon-carbon double bond in the monomer units, and more preferably contains 8 to 31 mol%. This can exhibit more excellent pickup performance.
In the above-mentioned acrylic copolymer, the proportion of the saturated branched alkyl (meth) acrylate ester unit having 7 or more and 11 or less carbon atoms in the alkyl moiety in the monomer unit is preferably 20 mol% or more and 70 mol% or less, and more preferably 30 mol% or more and 60 mol% or less. This can exhibit good pickup performance and further suppress so-called chip lifting.
In the present embodiment, the adhesive layer 22 of the dicing tape 20 may further include an isocyanate compound having a plurality of isocyanate groups in a molecule. By providing the isocyanate compound with a plurality of isocyanate groups in a molecule, the crosslinking reaction between the acrylic copolymers in the pressure-sensitive adhesive layer 22 can be advanced. Specifically, the crosslinking reaction by the isocyanate compound can be advanced by reacting one isocyanate group of the isocyanate compound with a hydroxyl group of the acrylic copolymer and reacting the other isocyanate group with a hydroxyl group of the other acrylic copolymer.
The isocyanate compound may be a compound synthesized by a urethanization reaction or the like.
Examples of the isocyanate compound include diisocyanates such as aliphatic diisocyanate, alicyclic diisocyanate, and araliphatic diisocyanate.
Further, examples of the isocyanate compound include polymeric polyisocyanates such as dimers and trimers of diisocyanates, and polymethylene polyphenylene polyisocyanates.
Examples of the isocyanate compound include polyisocyanates obtained by reacting an excess amount of the isocyanate compound with an active hydrogen-containing compound. Examples of the active hydrogen-containing compound include an active hydrogen-containing low molecular weight compound and an active hydrogen-containing high molecular weight compound.
As the isocyanate compound, allophanate polyisocyanate, biuret polyisocyanate, or the like can be used.
The isocyanate compounds can be used alone in 1 or a combination of 2 or more.
As the above-mentioned isocyanate compound, a reaction product of an aromatic diisocyanate and an active hydrogen-containing low molecular weight compound is preferable. Since the reaction rate of the reaction product of the aromatic diisocyanate is relatively slow, the adhesive layer 22 containing the reaction product is suppressed from being excessively cured. The isocyanate compound preferably has 3 or more isocyanate groups in the molecule.
The polymerization initiator contained in the adhesive layer 22 is a compound capable of initiating a polymerization reaction by applied thermal energy or light energy. By including the polymerization initiator in the pressure-sensitive adhesive layer 22, the crosslinking reaction between the acrylic copolymers can be advanced when thermal energy or optical energy is applied to the pressure-sensitive adhesive layer 22. Specifically, the pressure-sensitive adhesive layer 22 can be cured by initiating a polymerization reaction of polymerizable groups with each other between acrylic copolymers having polymerizable (meth) acrylate units containing radical polymerizable carbon-carbon double bonds. This can reduce the adhesive strength of the adhesive layer 22, and the die bond sheet 10 can be easily peeled from the cured adhesive layer 22 in the pickup step.
As the polymerization initiator, for example, a photopolymerization initiator, a thermal polymerization initiator, or the like is used. As the polymerization initiator, a general commercially available product can be used.
The adhesive layer 22 may contain other components than the above components. Examples of the other components include a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, an antistatic agent, a surfactant, and a light releasing agent. The kind and amount of the other components may be appropriately selected depending on the purpose.
The adhesive layer 22 has a phase separation structure when a cross section is observed with an electron microscope. In detail, the adhesive layer 22 has: a 1 st phase containing a radically polymerizable carbon-carbon double bond, and a 2 nd phase separated from the 1 st phase and having a lower content of radically polymerizable carbon-carbon double bonds than the 1 st phase. When the cross section is observed with an electron microscope, for example, the 1 st phase is represented by a darker color, and the 2 nd phase is represented by a lighter color. Specifically, when OsO is used for preparing a sample for electron microscope observation 4 When the dyeing treatment is performed, osmium reacts with an unsaturated bond (double bond), and the reacted portion becomes darker and reflects. Therefore, for example, the 1 st phase is a darker color, and contrast can be obtained in the observed image.
The phase separation structure may be, for example, a sea-island structure in which the 1 st phase is dispersed in the continuous 2 nd phase as shown in fig. 11. The phase separation structure may be a co-continuous phase separation structure in which the 1 st phase and the 2 nd phase form continuous phases, as shown in fig. 12, for example.
When the cross section of the pressure-sensitive adhesive layer 22 is observed under the following measurement conditions with an electron microscope, the area ratio occupied by the 1 st phase is preferably 50% or more, and more preferably 60% or more. The area ratio may be 100% or less, or may be 90% or less.
(measurement conditions)
Method for preparing measurement sample from adhesive layer: ultra-thin slicing method using ultra-thin slicer
Observation magnification: 12,000 times of
Observation area: at least 9 μm 2 (e.g., a square of 3 μm square)
Staining treatment method for measurement sample: osO 4 And RuO 4
Area ratio calculation method: image analysis using product name "Image J
In the observation image of the measurement sample prepared by the dyeing treatment as described above, a black-looking portion and a gray-looking portion may coexist depending on the content of an unsaturated bond (double bond) in the pressure-sensitive adhesive layer 22. In this case, both a black-appearing part and a gray-appearing part are defined as the 1 st phase. In other words, the portion having the lowest unsaturated bond (double bond) content is the 2 nd phase, and the other portions are the 1 st phase.
In the present embodiment, the base layer 21 superimposed on the pressure-sensitive adhesive layer 22 may have a single-layer structure or a laminated structure.
Each layer of the base layer 21 is, for example, a fibrous sheet such as a metal foil, paper, or cloth, a rubber sheet, or a resin film.
Examples of the fiber sheet constituting the base material layer 21 include paper, woven fabric, and nonwoven fabric.
Examples of the material of the resin film include polyolefins such as Polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymers; ethylene copolymers such as ethylene-vinyl acetate copolymers (EVA), ionomer resins, ethylene- (meth) acrylic acid copolymers, and ethylene- (meth) acrylic acid ester (random, alternating) copolymers; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); a polyacrylate; polyvinyl chloride (PVC); a polyurethane; a polycarbonate; polyphenylene Sulfide (PPS); polyamides such as aliphatic polyamides and wholly aromatic polyamides (aramid); polyetheretherketone (PEEK); a polyimide; a polyetherimide; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymer); cellulose or a cellulose derivative; a silicone-containing polymer; fluorine-containing polymers, and the like. These may be used alone in 1 kind or in combination of 2 or more kinds.
The base layer 21 is preferably made of a polymer material such as a resin film.
When the base layer 21 is a resin film, the resin film may be subjected to a stretching treatment or the like to control the deformability such as elongation.
The surface of the base material layer 21 may be subjected to a surface treatment in order to improve adhesion to the pressure-sensitive adhesive layer 22. As the surface treatment, for example, oxidation treatment based on a chemical method or a physical method such as chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, ionizing radiation treatment, or the like can be used. Further, coating treatment with a coating agent such as an anchor coating agent, a primer, or an adhesive may be performed.
The base layer 21 may be a single layer or may be composed of a plurality of layers (e.g., 3 layers). The thickness (total thickness) of the base material layer 21 may be 80 μm or more and 150 μm or less.
In order to impart releasability, the back surface side (side on which the pressure-sensitive adhesive layer 22 is not superimposed) of the base material layer 21 may be subjected to a release treatment using a release agent (release agent) such as a silicone resin or a fluorine resin.
The base layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like, in view of being able to apply active energy rays such as ultraviolet rays to the pressure-sensitive adhesive layer 22 from the back side.
The dicing tape 20 may be provided with a release sheet covering one surface of the pressure-sensitive adhesive layer 22 (the surface of the pressure-sensitive adhesive layer 22 that does not overlap with the base material layer 21) in a state before use. The release sheet is used to protect the adhesive layer 22 and is peeled off before the die-bonding sheet 10 is attached to the adhesive layer 22.
As the release sheet, for example, a plastic film or paper surface-treated with a release agent such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide can be used.
Note that the release sheet may be used as a support material for supporting the adhesive layer 22. In particular, a release sheet is suitably used when the pressure-sensitive adhesive layer 22 is superposed on the base layer 21. Specifically, the pressure-sensitive adhesive layer 22 can be laminated on the base material layer 21 by laminating the pressure-sensitive adhesive layer 22 on the base material layer 21 in a state where the release sheet and the pressure-sensitive adhesive layer 22 are laminated, and then peeling (transferring) the release sheet.
The dicing die-bonding film 1 of the present embodiment may include a release sheet covering one surface of the die-bonding sheet 10 (the surface of the die-bonding sheet 10 not overlapping with the adhesive layer 22) in a state before use. The peeling sheet is used to protect the die bonding sheet 10, and is peeled off immediately before an adherend (e.g., a semiconductor wafer) is attached to the die bonding sheet 10.
The release sheet may be used as a support material for supporting the die bond sheet 10. The release sheet is suitably used when the die bonding sheet 10 is superposed on the adhesive layer 22. Specifically, the die-bonding sheet 10 can be superimposed on the adhesive layer 22 by superimposing the die-bonding sheet 10 on the adhesive layer 22 in a state where the release sheet and the die-bonding sheet 10 are stacked, and then peeling (transferring) the release sheet after the superimposition.
< die bonding sheet for dicing die bonding film >
As shown in fig. 1, the die bond sheet 10 is overlapped with the adhesive layer 22 of the dicing tape 20.
Regarding the peeling force between the pressure-sensitive adhesive layer 22 and the die-bonding sheet 10, the peeling force (a) of the pressure-sensitive adhesive layer 22 before curing by the active energy ray and the peeling force (B) after curing preferably satisfy the following formula (1), and more preferably satisfy the following formula (2). The following numerical value of (a)/(B) may be 25.0 or less.
(A) L (B) >7.0 formula (1)
(A) L (B) >8.0 formula (2)
By satisfying the above expression (1), more excellent pickup performance can be exhibited. In order to measure the peel force (B) after curing, the above peel force was measured after the pressure-sensitive adhesive layer 22 was sufficiently cured. For example, a high-pressure mercury lamp (60 mW/cm) 2 ) Irradiating from the substrate layer side with at least 150mJ of intensity/cm 2 The active energy ray of (2) to cure the adhesive layer.
The peel force between the pressure-sensitive adhesive layer 22 and the die-bonding sheet 10 may be 0.30[ n/20mm ] or more, or 0.50[ n/20mm ] or more before the pressure-sensitive adhesive layer 22 is cured by the active energy ray (i.e., the value of (a) above). (A) The value of (B) may be 2.50[ n/20mm ] or less, may be less than 1.90[ n/20mm ], or may be 1.80[ n/20mm ] or less. This can more sufficiently suppress so-called chip floating.
The peel force between the pressure-sensitive adhesive layer 22 and the die-bonding sheet 10 may be 0.03[ n/20mm ] or more, 0.06[ n/20mm ] or more, or 0.07[ n/20mm ] or more after the pressure-sensitive adhesive layer 22 has been cured by an active energy ray (i.e., the value of (B) above). (A) The value of (A) may be 0.10[ 2], [ N/20mm ] or less, may be less than 0.09[ N/20mm ], or may be 0.08[ 2], [ N/20mm ] or less. This can exhibit more excellent pickup performance.
The numerical value of (a) can be further increased by, for example, increasing the content ratio of the radical polymerizable carbon-carbon double bonds in the acrylic copolymer in the pressure-sensitive adhesive layer 22. In addition, for example, the numerical value of (a) can be further increased by increasing the content ratio of the hydroxyl group-containing (meth) acrylate unit in the acrylic copolymer.
The numerical value of (B) can be further reduced by, for example, increasing the content ratio of the radical polymerizable carbon-carbon double bonds in the acrylic copolymer in the pressure-sensitive adhesive layer 22. In addition, the numerical value of (B) can be further reduced by increasing the content ratio of the aliphatic alkyl (meth) acrylate unit in the acrylic copolymer.
By changing (a) and (B) as described above, the above-mentioned value of (a)/(B) can be adjusted.
The die-bonding sheet 10 contains a crosslinkable group-containing acrylic polymer having a crosslinkable group causing a crosslinking reaction by a heat curing treatment in a molecule. The crosslinkable group-containing acrylic polymer is a polymer compound obtained by polymerizing at least a (meth) acrylate monomer.
The crosslinkable group-containing acrylic polymer usually has the crosslinkable group in a side chain. The crosslinkable group-containing acrylic polymer may have the crosslinkable group at the end of the side chain. The crosslinkable group-containing acrylic polymer may have the crosslinkable group at least one of both ends of the main chain.
The crosslinkable group of the crosslinkable group-containing acrylic polymer in the molecule is not particularly limited as long as it is a functional group which causes a crosslinking reaction by a heat curing treatment.
Examples of the crosslinkable group include a hydroxyl group and a carboxyl group. These crosslinkable groups can undergo a crosslinking reaction with an epoxy group or an isocyanate group. For example, the crosslinkable group-containing acrylic polymer having at least one of a hydroxyl group and a carboxyl group in the molecule can cause a crosslinking reaction between a compound having an epoxy group or an isocyanate group in the molecule (for example, an epoxy resin described later).
Examples of the crosslinkable group include an epoxy group and an isocyanate group. These crosslinkable groups can undergo a crosslinking reaction with a hydroxyl group or a carboxyl group. For example, the crosslinkable group-containing acrylic polymer having at least one of an epoxy group and an isocyanate group in a molecule can be subjected to a crosslinking reaction with a compound having at least one of a hydroxyl group and a carboxyl group in a molecule (for example, a phenol resin described later).
In the present embodiment, the acrylic polymer containing a crosslinkable group contained in the die-bonding sheet 10 preferably contains at least one of a carboxyl group and an epoxy group as a crosslinkable group. This enables the die bonding sheet 10 to be more favorably adhered to an adherend.
In order to more fully exhibit adhesiveness to an adherend after curing (described in detail later), the die bonding sheet 10 is required to have a performance of having a high cohesive force after curing. In order to improve the cohesive force after curing, the organic components contained in the die-bonding sheet 10 must sufficiently undergo a crosslinking reaction with each other so that the die-bonding sheet 10 is sufficiently cured. In order to sufficiently perform curing, the crosslinkable group-containing acrylic polymer preferably has a functional group having a relatively high reactivity, such as an epoxy group (glycidyl group) or a carboxyl group.
In the crosslinkable group-containing acrylic polymer, the proportion of the structural unit of the crosslinkable group-containing monomer may be 0.1% by mass or more and 60.0% by mass or less, may be 0.5% by mass or more and 40.0% by mass or less, may be more preferably 1.0% by mass or more and 30.0% by mass or less, and may be further preferably 3.0% by mass or more and 20.0% by mass or less.
By setting the above ratio to 0.1 mass% or more, curing at the time of the thermosetting treatment of the die bonding sheet 10 can be more sufficiently performed. On the other hand, when the above-mentioned proportion is 60.0 mass% or less, the crosslinking reactivity of the crosslinkable group-containing acrylic polymer can be appropriately suppressed, and the stability with time can be improved.
When the crosslinkable group-containing acrylic polymer has a hydroxyl group or a carboxyl group as a crosslinkable group in the molecule, the ratio of the structural unit of the crosslinkable group-containing monomer in the crosslinkable group-containing acrylic polymer may be 0.1% by mass or more and 20.0% by mass or less, may be 0.5% by mass or more and 10.0% by mass or less, may be more preferably 0.8% by mass or more and 15.0% by mass or less, and may be more preferably 1.0% by mass or more and 10.0% by mass or less.
When the crosslinkable group-containing acrylic polymer has an epoxy group as a crosslinkable group in a molecule, the ratio of the structural unit containing an epoxy group in the crosslinkable group-containing acrylic polymer may be 5% by mass or more and 60% by mass or less, may be 6% by mass or more and 40% by mass or less, and more preferably may be 7% by mass or more and 20% by mass or less.
The structural unit is a structure derived from each monomer after polymerization of a monomer (for example, 2-ethylhexyl acrylate, hydroxyethyl acrylate, or the like) used in obtaining the crosslinkable group-containing acrylic polymer. The same applies to the following.
The die-bonding sheet 10 of the present embodiment may contain 1 crosslinkable group-containing acrylic polymer or may contain a plurality of (for example, 2) crosslinkable group-containing acrylic polymers.
For example, in the case where the die-bonding sheet 10 contains 2 types of crosslinkable group-containing acrylic polymers, one crosslinkable group and the other crosslinkable group of one of the 2 types of crosslinkable group-containing acrylic polymers are subjected to a crosslinking reaction with each other. Specifically, the crosslinkable group-containing acrylic polymer having at least one of a hydroxyl group or a carboxyl group as a crosslinkable group in a molecule and the crosslinkable group-containing acrylic polymer having at least one of an epoxy group or an isocyanate group as a crosslinkable group in a molecule can be subjected to a crosslinking reaction with each other.
The crosslinkable group-containing acrylic polymer can be synthesized, for example, by a usual polymerization method using a radical polymerization initiator.
The crosslinkable group-containing acrylic polymer preferably contains a structural unit of an alkyl (meth) acrylate monomer at the largest mass ratio among structural units in the molecule. Examples of the alkyl (meth) acrylate monomer include C1 to C18 alkyl (meth) acrylate monomers in which the number of carbon atoms in the alkyl (hydrocarbon) group is 1 to 18.
Examples of the alkyl (meth) acrylate monomer include a saturated linear alkyl (meth) acrylate monomer, a saturated branched alkyl (meth) acrylate monomer, and the like.
Examples of the saturated linear alkyl (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, myristyl (meth) acrylate, palmityl (meth) acrylate, and stearyl (meth) acrylate. The number of carbon atoms in the linear alkyl moiety is preferably 2 or more and 8 or less.
Examples of the saturated branched alkyl (meth) acrylate monomer include isoheptyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. The alkyl moiety may have any of an iso (iso) structure, a secondary (sec) structure, a novel (neo) structure, or a tertiary (tert) structure.
The crosslinkable group-containing acrylic polymer contains a structural unit derived from a crosslinkable group-containing monomer copolymerizable with the alkyl (meth) acrylate monomer.
In the present embodiment, the crosslinkable group-containing acrylic polymer is an acrylic polymer obtained by copolymerizing at least an alkyl (meth) acrylate monomer and a crosslinkable group-containing monomer. In other words, the crosslinkable group-containing acrylic polymer has a structure in which the structural unit of the alkyl (meth) acrylate monomer and the structural unit of the crosslinkable group-containing monomer are randomly connected in this order.
Examples of the crosslinkable group-containing monomer include a carboxyl group-containing (meth) acrylic monomer, an acid anhydride (meth) acrylic monomer, a hydroxyl group-containing (hydroxy) group (meth) acrylic monomer, an epoxy group-containing (glycidyl) meth) acrylic monomer, an isocyanate group-containing (meth) acrylic monomer, a sulfonic acid group-containing (meth) acrylic monomer, a phosphoric acid group-containing (meth) acrylic monomer, and a functional group-containing monomer such as acrylamide and acrylonitrile. The crosslinkable group-containing monomer may have an ether group, an ester group or the like in a molecule.
The crosslinkable group-containing acrylic polymer is preferably:
a copolymer of at least 1 crosslinkable group-containing monomer selected from the group consisting of a carboxyl group-containing (meth) acrylic monomer, a hydroxyl group-containing (meth) acrylic monomer, an epoxy group-containing (meth) acrylic monomer, and an isocyanate group-containing (meth) acrylic monomer, and an alkyl (meth) acrylate (particularly, an alkyl (meth) acrylate having 8 or less carbon atoms in the alkyl moiety).
Examples of the carboxyl group-containing (meth) acrylic monomer include (meth) acrylic acid and a mono (2- (meth) acryloyloxyethyl) succinate monomer. The carboxyl group may be disposed at a terminal portion of the monomer structure or may be bonded to a hydrocarbon other than the terminal portion.
Examples of the hydroxyl group-containing (meth) acrylic monomer include a hydroxyethyl (meth) acrylate monomer, a hydroxypropyl (meth) acrylate monomer, and a hydroxybutyl (meth) acrylate monomer. The hydroxyl group may be disposed at a terminal portion of the monomer structure, or may be bonded to a hydrocarbon other than the terminal portion.
Examples of the epoxy group-containing (meth) acrylic monomer include glycidyl (meth) acrylate monomers, 4-hydroxybutyl (meth) acrylate glycidyl ether, and the like. The epoxy group may be disposed at a terminal portion of the monomer structure, or may be bonded to a hydrocarbon other than the terminal portion.
Examples of the isocyanate group-containing (meth) acrylic monomer include 2-methacryloyloxyethyl isocyanate, 1- (bisacryloxymethyl) ethyl isocyanate, 2-acryloxyethyl isocyanate, and 2- (2-methacryloyloxyethyl) ethyl isocyanate.
The die-bonding sheet 10 may contain components other than the crosslinkable group-containing acrylic polymer described above. For example, the die-bonding sheet 10 may contain at least one of a thermosetting resin and a thermoplastic resin other than the crosslinkable group-containing acrylic polymer.
Examples of the thermosetting resin include epoxy resins, phenol resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, thermosetting polyimide resins, and the like. As the thermosetting resin, only 1 kind or 2 or more kinds can be used.
Examples of the epoxy resin include bisphenol a type, bisphenol F type, bisphenol S type, brominated bisphenol a type, hydrogenated bisphenol a type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolac type, o-cresol novolac type, trishydroxyphenylmethane type, tetraphenylethane type, hydantoin type, triglycidyl isocyanurate type, and glycidylamine type epoxy resins.
Phenolic resins can be used as curing agents for epoxy resins. Examples of the phenol resin include novolac-type phenol resins, resol-type phenol resins, polyoxystyrenes such as poly-p-oxystyrene, and the like.
Examples of the novolak type phenol resin include a phenol novolak resin, a phenol aralkyl resin, a cresol novolak resin, a tert-butylphenol novolak resin, a nonylphenol novolak resin, and the like.
The phenolic resin may have a hydroxyl group equivalent [ g/eq ] of 90 to 220, for example.
As the above phenol resin, only 1 kind or 2 or more kinds can be used.
In the present embodiment, the die-bonding sheet 10 may contain the crosslinkable group-containing acrylic polymer and the thermosetting resin, which are capable of undergoing a crosslinking reaction with each other. In addition, the die-bonding sheet 10 may contain a plurality of types of crosslinkable group-containing acrylic polymers that undergo a crosslinking reaction with each other.
For example, the die-bonding sheet 10 may contain a carboxyl group-containing acrylic polymer or a hydroxyl group-containing acrylic polymer as a crosslinkable group-containing acrylic polymer, and may contain an epoxy resin as a thermosetting resin. Thus, the carboxyl group or the hydroxyl group of the crosslinkable group-containing acrylic polymer can be crosslinked with the epoxy group of the epoxy resin to sufficiently cure the die bond sheet 10.
Examples of the thermoplastic resin other than the crosslinkable group-containing acrylic polymer that can be contained in the die-bonding sheet 10 include polyamide resins such as natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, 6-polyamide resin, 6-polyamide resin, phenoxy resin, acrylic resin containing no crosslinkable functional group in the molecule, saturated polyester resins such as PET and PBT, polyamideimide resin, and fluorine resins.
As the thermoplastic resin, only 1 kind or 2 or more kinds can be used.
The content ratio of the crosslinkable group-containing acrylic polymer is preferably 8 parts by mass or more and 100 parts by mass or less, more preferably 30 parts by mass or more, and still more preferably 40 parts by mass or more, relative to the total mass of the die-bonding sheet 10.
In the die-bonding sheet 10, the content ratio of the crosslinkable group-containing acrylic polymer is preferably 15 parts by mass or more and 100 parts by mass or less, more preferably 40 parts by mass or more and 98 parts by mass or less, and still more preferably 60 parts by mass or more, with respect to 100 parts by mass of the organic component other than the filler (for example, the crosslinkable group-containing acrylic polymer, the thermosetting resin, the curing catalyst, and the like, the silane coupling agent, and the dye). The elasticity and viscosity of the die bond sheet 10 can be adjusted by changing the content of the thermosetting resin in the die bond sheet 10.
On the other hand, the content ratio of the thermosetting resin may be 40 parts by mass or less, or 10 parts by mass or less, with respect to 100 parts by mass of the organic component.
The die-bonding sheet 10 may or may not contain a filler. By changing the amount of the filler in the die bond sheet 10, the elasticity and viscosity of the die bond sheet 10 can be adjusted more easily. Further, physical properties such as electrical conductivity, thermal conductivity, and elastic modulus of the die bonding sheet 10 can be adjusted.
Examples of the filler include inorganic fillers and organic fillers. As the filler, an inorganic filler is preferable.
Examples of the inorganic filler include fillers containing silica such as aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum nitride, boron nitride, crystalline silica, amorphous silica and the like. Examples of the material of the inorganic filler include simple metals such as aluminum, gold, silver, copper, and nickel, and alloys thereof. And may be aluminum borate whisker, amorphous carbon black, graphite, etc. The filler may be in the form of a sphere, needle, or sheet. As the filler, can use the above-mentioned only 1 or more than 2.
When the die-bonding sheet 10 contains a filler, the content of the filler may be 50 mass% or less, 40 mass% or less, or 30 mass% or less of the total mass of the die-bonding sheet 10. The content of the filler may be, for example, 5% by mass or more.
The die bond sheet 10 may contain other components as desired. Examples of the other components include a curing catalyst, a flame retardant, a silane coupling agent, an ion scavenger, and a dye.
Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resins.
Examples of the silane coupling agent include β - (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ -glycidoxypropyltrimethoxysilane, and γ -glycidoxypropylmethyldiethoxysilane.
Examples of the ion scavenger include hydrotalcites, bismuth hydroxide, and benzotriazole.
As the other additives, only 1 or 2 or more kinds can be used.
The die-bonding sheet 10 preferably contains the crosslinkable group-containing acrylic polymer, the thermosetting resin, and the filler, from the viewpoint of easy adjustment of elasticity and viscosity.
The thickness of the die bond sheet 10 is not particularly limited, and is, for example, 1 μm or more and 200 μm or less. The thickness may be 3 μm or more and 150 μm or less, or 5 μm or more and 100 μm or less. When the die bond sheet 10 is a laminate, the thickness is the total thickness of the laminate.
The chip bonding sheet 10 may have a single-layer structure, as shown in fig. 1, for example. In the present specification, a single layer means a layer having only the same composition. The state in which a plurality of layers formed of the same composition are stacked is also a single layer.
On the other hand, the die-bonding sheet 10 may have a multilayer structure in which layers of 2 or more different compositions are stacked, for example. When the die-bonding sheet 10 has a multilayer structure, at least 1 layer constituting the die-bonding sheet 10 contains the crosslinkable group-containing acrylic polymer described above, and may further contain a thermosetting resin as necessary.
Next, a method for manufacturing the die-bonding sheet 10 and the dicing die-bonding film 1 according to the present embodiment will be described.
< method for producing dicing die-bonding film >
The method for manufacturing the dicing die-bonding film 1 of the present embodiment includes:
a step of manufacturing a chip bonding sheet 10;
a step of manufacturing a dicing tape 20; and
and a step of overlapping the manufactured die bond sheet 10 with the dicing tape 20.
< Process for producing die bond sheet >
The step of producing the die bond sheet 10 includes:
a resin composition preparation step of preparing a resin composition for forming the die bonding sheet 10; and
and a die bond sheet forming step of forming the die bond sheet 10 from the resin composition.
In the resin composition preparation step, for example, the crosslinkable group-containing acrylic polymer and any of an epoxy resin, a curing catalyst for an epoxy resin, a phenol resin, or a solvent are mixed, and each resin is dissolved in the solvent to prepare a resin composition. The viscosity of the composition can be adjusted by varying the amount of the solvent. As these resins, commercially available products can be used.
In the die bond sheet forming step, for example, the resin composition prepared as described above is applied to a release sheet. The coating method is not particularly limited, and a general coating method such as roll coating, screen coating, and gravure coating is used. Next, the applied composition is cured by desolvation treatment, curing treatment, or the like as necessary to form the die bonding sheet 10.
< Process for producing dicing tape >
The step of manufacturing the dicing tape includes:
a synthesis step for synthesizing an acrylic copolymer;
a pressure-sensitive adhesive layer production step of producing a pressure-sensitive adhesive layer 22 by evaporating a solvent from a pressure-sensitive adhesive composition containing the acrylic copolymer, an isocyanate compound, a polymerization initiator, a solvent, and other components added as appropriate according to the purpose;
a substrate layer manufacturing step of manufacturing the substrate layer 21; and
and a laminating step of laminating the adhesive layer 22 and the base layer 21 to laminate the base layer 21 and the adhesive layer 22.
In the synthesis step, for example, the above aliphatic alkyl (meth) acrylate monomer and the hydroxyl group-containing (meth) acrylic monomer are subjected to radical polymerization to synthesize an acrylic copolymer intermediate.
The radical polymerization can be carried out by a conventional method. For example, an intermediate of an acrylic copolymer can be synthesized by dissolving the above monomers in a solvent, stirring the solution while heating, and adding a polymerization initiator. In order to adjust the molecular weight of the acrylic copolymer, the polymerization may be carried out in the presence of a chain transfer agent.
Next, a part of the hydroxyl groups of the hydroxyl group-containing (meth) acrylate unit contained in the acrylic copolymer intermediate and the isocyanate groups of the isocyanate group-containing polymerizable monomer are bonded by a urethanization reaction. Thus, a part of the hydroxyl group-containing (meth) acrylate unit becomes a polymerizable (meth) acrylate unit containing a radically polymerizable carbon-carbon double bond.
The carbamation reaction can be carried out by a conventional method. For example, the acrylic copolymer intermediate and the isocyanate group-containing polymerizable monomer are stirred while being heated in the presence of a solvent and a urethane-forming catalyst. This allows isocyanate group urethane bonds containing an isocyanate group polymerizable monomer to be bonded to a part of the hydroxyl groups of the acrylic copolymer intermediate.
In the pressure-sensitive adhesive layer producing step, for example, an acrylic copolymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare a pressure-sensitive adhesive composition. The viscosity of the composition can be adjusted by varying the amount of the solvent. Next, the adhesive composition is applied to a release sheet. As the coating method, for example, a general coating method such as roll coating, screen coating, gravure coating, or the like is used. The applied adhesive composition is cured by subjecting the applied composition to desolvation treatment, curing treatment, or the like, to produce the adhesive layer 22.
In the substrate layer production step, the substrate layer can be produced by forming a film by a usual method. Examples of the method for forming the film include a rolling film forming method, a casting method in an organic solvent, a inflation extrusion method in a closed system, a T-die extrusion method, and a dry lamination method. Coextrusion may also be used. As the base layer 21, a commercially available film or the like can be used.
In the laminating step, the pressure-sensitive adhesive layer 22 in a state of being superimposed on the release sheet is superimposed on the base layer 21 to be laminated. The release sheet may be in a state of being overlapped on the adhesive layer 22 until the time of use.
In order to promote the reaction between the crosslinking agent and the acrylic copolymer and to promote the reaction between the crosslinking agent and the surface portion of the base material layer 21, a curing step may be performed for 48 hours at 50 ℃.
Through these steps, the dicing tape 20 can be manufactured.
< step of superposing die bond sheet 10 and dicing tape 20 >
In the step of overlapping the die bond sheet 10 and the dicing tape 20, the die bond sheet 10 is attached to the adhesive layer 22 of the dicing tape 20 manufactured as described above.
In the above attachment, the release sheet is peeled from each of the pressure-sensitive adhesive layer 22 of the dicing tape 20 and the die-bonding sheet 10, and the die-bonding sheet 10 and the pressure-sensitive adhesive layer 22 are attached to each other so as to be in direct contact with each other. For example, the bonding may be performed by crimping. The temperature at the time of bonding is not particularly limited, and is, for example, 30 ℃ to 50 ℃, preferably 35 ℃ to 45 ℃. The linear pressure at the time of bonding is not particularly limited, but is preferably 0.1kgf/cm or more and 20kgf/cm or less, more preferably 1kgf/cm or more and 10kgf/cm or less.
Through the above-described steps, the dicing die-bonding film 1 manufactured as described above is used as an auxiliary tool for manufacturing a semiconductor device (semiconductor integrated circuit), for example. A method for manufacturing a semiconductor device (a method for using a dicing die-bonding film) will be described below.
< method for producing semiconductor device (method for Using dicing die-bonding film in producing semiconductor device) >
In a method for manufacturing a semiconductor device, chips are generally cut out from a semiconductor wafer on which a circuit surface is formed and assembled. In this case, the dicing die-bonding film of the present embodiment is used as a manufacturing aid.
The method for manufacturing a semiconductor device of the present embodiment includes:
a dicing step of dicing a wafer (semiconductor wafer) on which a circuit surface is formed into chips; and
and a pickup step of peeling the die bonding sheet attached to the pressure-sensitive adhesive layer (pressure-sensitive adhesive tape) of the dicing die bonding film from the pressure-sensitive adhesive layer (pressure-sensitive adhesive tape) together with the die.
In the method for manufacturing a semiconductor device according to the present embodiment, the cleaving step includes, for example: a stealth dicing step of forming a fragile portion in the semiconductor wafer to which the back grinding tape is attached by laser light and preparing the semiconductor wafer to be processed into chips (die) by a dicing process; a back grinding step of grinding the semiconductor wafer to which the back grinding tape is attached to reduce the thickness; a mounting step of attaching one surface (for example, a surface on the opposite side of the circuit surface) of the semiconductor wafer having a reduced thickness to the die bonding sheet 10, and fixing the semiconductor wafer to the dicing tape 20; and a spreading step of stretching the dicing tape 20 to cut the semiconductor wafer to produce chips (die) and to widen the intervals between the chips.
In the pickup step, the semiconductor chip (die) is taken out with the die bonding sheet 10 attached by peeling the space between the die bonding sheet 10 and the adhesive layer 22.
The method for manufacturing a semiconductor device of the present embodiment further includes: a die bonding step of bonding a die bonding sheet 10 attached to a semiconductor chip (die) to an adherend; a curing step of curing the die bonding sheet 10 bonded to the adherend; a wire bonding step of electrically connecting an electrode of an electronic circuit in the semiconductor chip (die) to an adherend with a wire; and a sealing step of sealing the semiconductor chip (die) and the lead on the adherend with a thermosetting resin.
The Stealth Dicing step is a step in the so-called SDBG (Stealth Dicing Before polishing) process. In the stealth dicing step, as shown in fig. 2A to 2C, a fragile portion for cutting the wafer on which the circuit surface is formed into chips (die) is formed inside the semiconductor wafer W. Specifically, the back grinding tape G is attached to the circuit surface of the semiconductor wafer W (see fig. 2A). The grinding process (pre-back grinding process) by the grinding pad K is performed in a state where the back grinding tape G is attached until the semiconductor wafer W becomes a predetermined thickness (see fig. 2B). The semiconductor wafer W having a reduced thickness is irradiated with laser light, whereby a fragile portion is formed inside the semiconductor wafer W (see fig. 2C).
A half-dicing process may be performed instead of the stealth dicing process. The half-cutting step is a step in a so-called DBG (Dicing Before Grinding) process.
In the half-cut step, in order to process a semiconductor wafer into chips (die) by a cleaving process, grooves are formed in the semiconductor wafer, and then the semiconductor wafer is ground to reduce its thickness.
Specifically, in the half-cut step, a half-cut process for cutting the wafer on which the circuit surface is formed into chips (die) is performed. More specifically, a tape for wafer processing is attached to the surface of the semiconductor wafer opposite to the circuit surface. Further, the dicing ring is attached to the wafer processing tape. The dividing grooves are formed in a state where the wafer processing tape is attached. The back grinding tape is attached to the surface on which the grooves are formed, and the wafer processing tape that has started to be attached is peeled off.
As described above, the Dicing die-bonding film according to the present embodiment is preferably used in an SDBG (straight Dicing form cutting) process or a DBG (straight Dicing form cutting) process for manufacturing a semiconductor chip by Dicing a semiconductor wafer.
In the back grinding step, as shown in fig. 2D, the semiconductor wafer W with the back grinding tape G attached thereto is further subjected to grinding processing to reduce the thickness of the semiconductor wafer W to the thickness of the chips (die) produced by the subsequent cleaving processing. For example, the semiconductor wafer W subjected to the half-cut processing may be ground to a predetermined thickness without being singulated. When the grinding process is performed in this manner, the semiconductor wafer W is cut into chips and the die bonding piece 10 is also cut through in the subsequent expansion process (particularly, low-temperature expansion process). On the other hand, the grinding process may be performed until the semiconductor wafer W after the half-cut process is singulated. When the grinding process is performed in this manner, in the subsequent expansion process (particularly, low-temperature expansion process), for example, the chip bonding sheet 10 is cut while the interval between the adjacent chips is increased.
In the mounting step, as shown in fig. 3A to 3B, the semiconductor wafer W is fixed to the dicing tape 20. Specifically, the dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and the semiconductor wafer W reduced in thickness by the cutting process as described above is attached to the exposed surface of the die bond sheet 10 (see fig. 3A). Next, the back-grinding tape G is peeled off from the semiconductor wafer W (see fig. 3B).
The die bond sheet 10 may be cut by irradiation of, for example, laser light before the expanding process. Specifically, when the semiconductor wafer W is singulated by the cutting process, the die bonding sheet 10 which is not yet cut but is stacked on the semiconductor wafer and is obtained by dicing the semiconductor wafer W can be cut by irradiation with laser light. Then, the spacing between adjacent chips can be enlarged by the expanding process.
In the expanding step, as shown in fig. 4A to 4C, the interval between the semiconductor chips (die) X produced by cleaving is expanded. Specifically, the dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and then fixed to the holder H of the expanding device (see fig. 4A). The cut die-bonding film 1 is stretched to be spread in the planar direction by lifting up the lifting member U provided in the spreading device from the lower side of the cut die-bonding film 1 (see fig. 4B). Thereby, the semiconductor wafer W is cut under a specific temperature condition. The temperature conditions are, for example, -20 to 0 ℃, preferably-15 to 0 ℃, and more preferably-10 to-5 ℃. The expansion state is released by lowering the jack-up member U (refer to fig. 4C, which is a low-temperature expansion process up to now).
Further, in the expanding step, as shown in fig. 5A to 5B, the dicing tape 20 is stretched under a higher temperature condition (for example, 10 to 25 ℃) to expand the area. Thereby, the adjacent semiconductor chips X after the dicing are separated in the surface direction of the thin film surface, and the cuts (gaps) are further enlarged (normal temperature expansion step).
In the case of performing the DBG process, the die bond sheet may be cut at a low temperature or may be cut with a laser in the expanding step. When the die bond sheet is diced with a laser, the expansion step may be performed at a low temperature after the die bond sheet is diced.
Before the pickup step, for example, the pressure-sensitive adhesive layer 22 stacked on the base material layer 21 is irradiated with ultraviolet rays from the base material layer 21 side, thereby curing the pressure-sensitive adhesive layer 22 (curing step).
In the pickup step, as shown in fig. 6, the semiconductor chip X with the die bond sheet 10 attached thereto is peeled off from the adhesive layer 22 of the dicing tape 20. Specifically, the pin member P is raised to lift the semiconductor chip X to be picked up via the dicing tape 20. The semiconductor chip X lifted up is held by the suction jig J.
By using the dicing die-bonding film according to the present embodiment described above, good pickup performance can be exhibited in the pickup step.
In the die bonding step, the semiconductor chip X with the die bonding sheet 10 attached thereto is bonded to the adherend Z. In the die bonding step, as shown in fig. 7, for example, the semiconductor chips X with the die bonding sheet 10 attached thereto may be stacked several times. In this manner, when manufacturing a chip-embedded semiconductor device (FOD [ Film on Die ] type semiconductor device), the Die bonding pad 10 can be used to embed a semiconductor chip.
In the curing step, the die-bonding sheet 10 is cured to increase the reactivity of the crosslinkable group (for example, epoxy group) in the crosslinkable group-containing acrylic polymer contained in the die-bonding sheet 10, and for example, heat treatment is performed at a temperature of 100 ℃ to 180 ℃.
In the wire bonding step, as shown in fig. 8, the semiconductor chip X (die) and the adherend Z are heated and connected by the wire L. Therefore, the crosslinkable group in the crosslinkable group-containing acrylic polymer contained in the die bonding sheet 10 is reactively reacted again by heating, and the curing reaction of the die bonding sheet 10 proceeds.
In the wire bonding step, a compressive force may be applied to the die bonding pad 10 in the thickness direction.
In the sealing step, as shown in fig. 9, the semiconductor chip X (die) and the die bonding sheet 10 are sealed with a thermosetting resin M such as an epoxy resin. In the sealing step, the thermosetting resin M is subjected to a heat treatment at a temperature of, for example, 100 ℃ to 180 ℃ in order to progress a curing reaction.
In recent years, in the semiconductor industry, with further progress in integration technology, there are strong demands for thinner semiconductor chips (for example, a thickness of 20 μm or more and 50 μm or less) and thinner die bonding sheets (for example, a thickness of 1 μm or more and 40 μm or less, preferably 7 μm or less, and more preferably 5 μm or less).
An electronic circuit is formed on one surface of such a thin semiconductor chip. When an electronic circuit is formed on one surface of a thin semiconductor chip, the semiconductor chip is not resistant to internal stress and slightly deformed (e.g., warped), and the die bonding sheet is also warped due to the deformation (see fig. 10).
In the expansion step, particularly in the normal temperature expansion step, since the dicing tape 20 is pulled in the surface direction with a strong force, if the chip is warped, the dicing tape 20 and the die bonding sheet 10 are peeled off, and a so-called chip lifting phenomenon occurs. In order to suppress the chip lifting, a high adhesive force is required between the dicing tape 20 and the chip bonding sheet 10 in the expanding step.
On the other hand, in the pickup step, it is required to be able to easily peel the die bond sheet 10 from the dicing tape 20 (good pickup property). In order to exert the contradictory properties, for example, the dicing tape 20 is designed in such a manner that the adhesive layer 22 of the dicing tape 20 can be cured by irradiation of an active energy ray. Specifically, the low-temperature expansion step for cleaving and the normal-temperature expansion step for securing the chip-to-chip distance in the expansion step are performed in a state where the pressure-sensitive adhesive layer 22 has a high adhesive force before the irradiation with the active energy ray. On the other hand, the adhesive layer 22 is irradiated with active energy rays before the pickup step, and the adhesive force of the adhesive layer 22 is reduced.
In the present embodiment, the acrylic copolymer contained in the pressure-sensitive adhesive layer 22 contains a hydroxyl group-containing (meth) acrylate unit as a crosslinkable group-containing (meth) acrylate unit at a predetermined mol%. In this manner, the pressure-sensitive adhesive layer 22 is designed such that the polarity of the pressure-sensitive adhesive layer 22 before curing becomes moderately high. This can suitably improve the adhesion between the pressure-sensitive adhesive layer 22 before curing and the die bonding sheet 10, and can strongly adhere the pressure-sensitive adhesive layer 22 before curing to the die bonding sheet 10. In addition, when the crosslinkable group-containing (meth) acrylate unit has a radical polymerizable carbon-carbon double bond, the die-bonding sheet 10 can be more easily peeled from the cured pressure-sensitive adhesive layer 22, and more excellent pickup properties are exhibited.
In the present embodiment, the acrylic copolymer contained in the pressure-sensitive adhesive layer 22 contains an aliphatic acrylic (meth) acrylate unit in a predetermined mol%. Thus, the pressure-sensitive adhesive layer 22 is designed so that the polarity of the pressure-sensitive adhesive layer 22 after curing with the active energy ray becomes low. This can weaken the adhesion between the pressure-sensitive adhesive layer 22 and the die-bonding sheet 10 after irradiation with active energy rays, and improve the peelability between the cured pressure-sensitive adhesive layer 22 and the die-bonding sheet 10. In this way, in the present embodiment, since the polarity of the adhesive layer 22 after curing by irradiation with the active energy ray is low, the interface interaction with the die bond sheet 10 having a high polarity is small. Therefore, the die-bonding sheet 10 is easily peeled from the cured adhesive layer 22.
The adhesive tape, dicing die-bonding film, and method for manufacturing a semiconductor device according to the present embodiment are as described above by way of example, and the present invention is not limited to the dicing die-bonding film and the like described above by way of example.
That is, various modes used in a general method for manufacturing a dicing die-bonding film or a semiconductor device can be adopted within a range not to impair the effects of the present invention.
Matters disclosed in the present specification include the following.
(1)
An adhesive tape used as an adhesive layer of a dicing die-bonding film, the dicing die-bonding film comprising: the adhesive layer and a die bonding sheet superposed on the adhesive layer,
the adhesive tape comprises an acrylic copolymer having, as monomer units in the molecule, at least: an aliphatic alkyl (meth) acrylate unit having an alkyl moiety with 12 or more carbon atoms and a crosslinkable group-containing (meth) acrylate unit,
the acrylic copolymer contains 10 to 85 mol% of the aliphatic alkyl (meth) acrylate unit and 15 to 35 mol% of the crosslinkable group-containing (meth) acrylate unit.
(2)
The pressure-sensitive adhesive tape according to the item (1), wherein a part of the crosslinkable group-containing (meth) acrylate units in the acrylic copolymer has a radically polymerizable carbon-carbon double bond.
(3)
The adhesive tape according to the item (2), wherein the acrylic copolymer contains the crosslinkable group-containing (meth) acrylate unit having the radically polymerizable carbon-carbon double bond in an amount of 8 to 31 mol% based on the total monomer units.
(4)
The adhesive tape according to any one of the above (1) to (3), wherein the proportion of the aliphatic alkyl (meth) acrylate unit in the entire monomer units in the acrylic copolymer is 15 mol% or more and 40 mol% or less.
(5)
The adhesive tape according to any one of the above (1) to (4), wherein the adhesive tape has a phase separation structure when a cross section is observed with an electron microscope.
(6)
The adhesive tape according to any one of the above (1) to (5), wherein the acrylic copolymer contains, as the crosslinkable group-containing (meth) acrylate unit, a hydroxyl group-containing (meth) acrylate unit and a polymerizable (meth) acrylate unit having a radical polymerizable carbon-carbon double bond (polymerizable unsaturated double bond),
the acrylic copolymer further contains, as the alkyl (meth) acrylate ester unit, a saturated branched alkyl (meth) acrylate unit having an alkyl moiety of 8 to 10 carbon atoms and a saturated straight aliphatic alkyl (meth) acrylate unit having an alkyl moiety of 12 to 14 carbon atoms.
(7)
The pressure-sensitive adhesive tape according to the item (6), wherein the acrylic copolymer has a lower content of the polymerizable (meth) acrylate unit than a content of any one of the saturated branched alkyl (meth) acrylate unit and the saturated linear aliphatic alkyl (meth) acrylate unit.
(8)
The adhesive tape according to any one of the above (1) to (7), wherein the acrylic copolymer contains, as the alkyl (meth) acrylate unit, a saturated branched alkyl (meth) acrylate unit having an alkyl moiety of 7 or more and 11 or less carbon atoms and a saturated linear aliphatic alkyl (meth) acrylate unit having an alkyl moiety of 12 or more and 14 or less carbon atoms,
in the acrylic copolymer, the amount ratio of the saturated branched alkyl (meth) acrylate unit to the saturated linear aliphatic alkyl (meth) acrylate unit in terms of mole is 1.0 or more and 5.0 or less.
(9)
A dicing die-bonding film comprising:
a dicing tape comprising a pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive tape described in any one of (1) to (8) above, and a base material layer superposed on the pressure-sensitive adhesive layer; and
and a die bonding sheet overlapping the adhesive layer of the dicing tape.
(10)
The dicing die-bonding film according to the item (9), wherein a peeling force between the pressure-sensitive adhesive layer and the die-bonding sheet between the pressure-sensitive adhesive layer before curing by the active energy ray (a) and a peeling force after curing (B) satisfy the following formula (1).
(A) L (B) >7.0 formula (1)
(11)
The dicing die-bonding film according to the above (10), wherein the (A)/(B) satisfies the following formula (2).
(A) L (B) >8.0 formula (2)
(12)
A method for manufacturing a semiconductor device, comprising:
a cutting step of cutting the wafer (pattern wafer) on which the circuit surface is formed into chips; and
a pickup step of peeling the die bonding sheet attached to the adhesive tape of the dicing die bonding film described in any one of (9) to (11) from the adhesive tape together with the chip.
[ examples ]
Next, the present invention will be described in more detail by way of experimental examples, but the present invention is not limited to these.
The dicing tape was manufactured as follows. Further, the dicing tape is bonded to a die bonding sheet to produce a dicing die bonding film.
< preparation of dicing tape >
(raw material monomer for acrylic copolymer)
2-hydroxyethyl acrylate (HEA)
2-hydroxyethyl methacrylate (HEMA)
4-hydroxybutyl acrylate (4 HBA)
Ethyl Acrylate (EA)
2-ethylhexyl acrylate (2 EHA)
Isononyl acrylate (INA)
Lauryl Acrylate (LA)
Acryloylmorpholine (ACMO)
(examples 1 to 8)/(comparative examples 1 to 4)
Each raw material was charged into a reaction vessel equipped with a condenser tube, a nitrogen gas inlet tube, a thermometer, and a stirrer so as to have a composition of the formulation shown in table 1. Azobisisobutyronitrile (AIBN) was used as a thermal polymerization initiator in an amount of 0.2 parts by weight based on 100 parts by weight of the total monomer. Ethyl acetate was added as a reaction solvent so that the concentration of all monomers became a predetermined concentration (for example, 35 mass%). An intermediate of the acrylic copolymer is obtained by carrying out a polymerization treatment at 62 ℃ for a predetermined time (for example, 6 hours) and further carrying out a polymerization treatment at 75 ℃ for a predetermined time (for example, 2 hours) in a nitrogen gas flow.
In each example and each comparative example, the monomer concentration and the polymerization time at the time of polymerization are shown in table 2.
To the liquid containing the intermediate of the acrylic copolymer prepared as described above, 2-methacryloyloxyethyl isocyanate (hereinafter, also referred to as MOI) was added so as to have a molar ratio (expressed as polymerizable group-containing monomer units in table 1) shown in table 1 with respect to the total amount of monomers blended at the time of polymerization. For example, in example 1, the MOI was added so that the MOI became 14 moles with respect to 100 moles of the total monomers blended during the polymerization. Further, dibutyltin dilaurate was added as a reaction catalyst in an amount of 0.5 mass% based on the MOI. Then, the addition reaction treatment (urethanization treatment) was carried out at 50 ℃ for 12 hours in an air stream to obtain an acrylic copolymer.
Next, the following compounding ingredients were added to 100 parts by mass of the acrylic copolymer to prepare a binder solution.
Photopolymerization initiator: 3 parts by mass based on 100 parts by mass of the intermediate of the acrylic copolymer
(product name "Omnirad127D", manufactured by IGM Co., ltd.)
Polyisocyanate compound: 0.8 part by mass based on 100 parts by mass of an intermediate of an acrylic copolymer
(product name "CORONATE L", manufactured by Tosoh corporation)
Antioxidant: 0.01 part by mass based on 100 parts by mass of the intermediate of the acrylic copolymer
(product name "Irganox1010", manufactured by BASF Japan Ltd.)
The adhesive solution prepared as described above was applied to the treated surface of the silicone-treated PET release liner, and heat-dried at 120 ℃ for 2 minutes to form an adhesive layer having a thickness of 10 μm.
Subsequently, the pressure-sensitive adhesive layer was bonded to a base layer (a polyolefin film (125 μm thick) under the name "FUNCRARE NED #125" manufactured by Gunze Limited), and stored at 50 ℃ for 24 hours to produce a dicing tape.
< production of die bond sheet >
Acrylic polymer: 100 parts by mass
( The product name is PARACRON KG-8001, and the mass average molecular weight is: 1,200,000, glass transition temperature Tg:9 ℃ epoxy group-containing, manufactured by Kokusho Kogyo Co., ltd )
Phenol resin: 3 parts by mass of
(product name "MEHC-7851SS", manufactured by Minghe chemical Co., ltd., solid at 23 ℃ C.)
Silica filler: 10 parts by mass
(product name "SE2050-MCV", average particle diameter 500nm, ADMATECHS CO., LTD. Manufactured)
The above-described raw materials were added to a predetermined amount of methyl ethyl ketone and mixed to prepare an adhesive composition solution having a total solid content of 12 mass%. Next, an adhesive composition was applied to the silicone release-treated surface of the PET release liner (separator) having a silicone release-treated surface using an applicator to form a coating film. The coating film was dried by heating at 130 ℃ for 2 minutes to prepare a die bond sheet having a thickness of 10 μm on a PET release liner (separator).
< production of dicing die-bonding film >
The die bond sheet was punched into a circular shape having a diameter of 330mm, to thereby prepare a circular die bond sheet. A dicing die-bonding film was produced by bonding a circular die-bonding sheet to a dicing tape at room temperature using a laminator.
< observation of phase separation Structure in adhesive layer >
2 adhesive layers were prepared and the adhesive layers were attached to each other. Then, the film was thinned to a thickness of about 100nm by a microtome method using a microtome under a freezing atmosphere (-100 ℃). The above-described microtome method is performed on a cross section obtained by cutting the pressure-sensitive adhesive layer in the thickness direction.
Then, heavy metal staining (OsO) was performed on the filmed sample 4 And RuO 4 ) The dyed film sample was observed by TEM and a photograph was taken. Further, the observed photograph was subjected to image analysis, and the area ratio of the 1 st phase (phase having a higher content of polymerizable double bonds and becoming darker by dyeing) was calculated. When there is a gray-appearing portion, the total area of the black portion and the gray portion is defined as the area of the phase 1.
[ conditions for Transmission Electron Microscope (TEM) Observation ]
The device comprises the following steps: hitachi, HT7820
Acceleration voltage: 100kV
[ method for calculating area ratio ]
Image analysis software: product name 'ImageJ'
Photo magnification: observation magnification of 12,000 times
Area analyzed in the observation image: 13 μm 2
As a result of observation of the pressure-sensitive adhesive layer as described above, it was confirmed that at least the pressure-sensitive adhesive layer of the example had a phase separation structure as shown in fig. 11 and 12.
< measurement of physical Properties of dicing die-bonding film >
The dicing die-bonding films of examples and comparative examples were measured for the respective physical properties as follows.
[ peeling force (adhesive force) between adhesive layer and die bond sheet ]
The details of the method for measuring the above-described peeling force (adhesive force) before (before) and after (after) ultraviolet irradiation are as follows. The measurement results are shown in table 1. The ratio of the peel force before curing (adhesive force) to the peel force after curing (adhesive force) is also shown in table 1.
[ peeling force (after ultraviolet irradiation) between adhesive layer and die bond sheet ]
The peel force was measured by T-peel test. The measurement sample was prepared as follows.
The PET release liner (separator) was peeled off from the die bond sheet to expose one surface of the die bond sheet. A backing tape (product name "ELP BT315", manufactured by Rindong electrician Co., ltd.) was attached to the exposed surface. A high-pressure mercury lamp (product name "UM-810") 60mW/cm manufactured by Nindon Jing Ltd was used 2 ) Irradiating the substrate layer side with an intensity of 150mJ/cm 2 The adhesive layer is cured by the ultraviolet rays of (1). Then, the adhesive layer was cut out so as to have a width of 50mm × a length of 120mm, and the adhesive layer was used as a measurement sample. The prepared sample for measurement was subjected to a tensile tester (for example, product name "AUTOGRAPH AGX-V"),Manufactured by shimadzu corporation), a T-peel test was performed. The test conditions were a temperature of 25 ℃ and a tensile rate of 300 mm/min.
[ peeling force between adhesive layer and die bonding sheet (before ultraviolet irradiation) ]
The peel force was measured in the same manner as the above method except that the pressure-sensitive adhesive layer before curing was measured without being irradiated with ultraviolet rays, and the pressure-sensitive adhesive layer was cut out so as to have a size of 20mm in width × 120mm in length.
Table 1 shows the composition and physical properties of the die bond sheets in each example and each comparative example. In table 1, the mol% of the "OH group-containing monomer unit" and the mol% of the "polymerizable group-containing monomer unit" respectively represent the mol% of the hydroxyl group-containing (meth) acrylate unit and the mol% of the polymerizable (meth) acrylate unit in the acrylic copolymer. Since the isocyanate group of the MOI and the hydroxyl group of the hydroxyl group-containing (meth) acrylate unit undergo a urethanization reaction with a reaction efficiency of almost 100%, the mol% can be calculated based on the amount of the compound used in synthesizing the acrylic copolymer.
[ Table 1]
Figure BDA0003647052520000391
[ Table 2]
Figure BDA0003647052520000401
The performance of the dicing die-bonding film manufactured as described above was evaluated as follows.
< evaluation of Property (pickup Property based on pickup test) >
The semiconductor chip with the die bond sheet in a cut state was evaluated for pick-up properties. The semiconductor chip with the die bond sheet in a cut state was obtained as follows.
Specifically, a back surface polishing tape was attached to the surface of a 12-inch bare wafer (300 mm in diameter and 55 μm in thickness) having dividing grooves (10 mm × 10 mm) formed thereon by half-cut processing. Then, the surface of the 12-inch bare wafer (the surface opposite to the side to which the back surface polishing tape was attached) was polished to a depth of 25 μm using a back surface polisher (model DGP8760, manufactured by DISCO corporation). Thus, a bare wafer subjected to back grinding was obtained. The die bonding sheet of the dicing die bonding film of each example was attached to the side of the bare wafer subjected to back grinding opposite to the attachment surface of the back grinding tape. Thus, a bare wafer with a dicing die-bonding film was obtained. The bare wafer with the dicing die-bonding film is cut by a spreading process. In the expanding step, the back-side polishing tape was peeled off from the bare wafer and carried out using a Die separating apparatus (product name "Die separator DDS2300, manufactured by DISCO inc.) and, in the expanding step, cold expanding was performed and then normal-temperature expanding was performed.
Cold expansion is performed as follows. Specifically, a ring frame made of SUS (manufactured by DISCO inc.) having a diameter of 12 inches was attached to a frame attachment region on the adhesive layer of the dicing die bonding film attached to the bare wafer at room temperature. Then, the bare wafer with the SUS ring frame attached thereto was mounted on a chip separating apparatus. The cold spreading unit of the chip separation apparatus spreads the dicing tape for dicing the chip bonding film, thereby performing cold spreading. The conditions in this case were an expansion temperature of-15 ℃, an expansion rate of 100 mm/sec, and an expansion amount of 7mm. After the cold expansion, the semiconductor wafer is singulated (singulated) into a plurality of semiconductor chips. In addition, the die bond pads are also singulated to a size corresponding to the semiconductor chip. Thereby, a plurality of semiconductor chips with die bond pads are obtained.
After cold expansion, cold expansion is performed as follows. The dicing tape for dicing the die bond film is expanded by using the normal temperature expansion unit of the above-described die separating apparatus, thereby performing normal temperature expansion. The conditions at this time were a spreading temperature of 23. + -. 2 ℃, a spreading rate of 1 mm/sec, and a spreading amount of 10mm. The dicing tape expanded at normal temperature was subjected to heat shrinkage treatment at a temperature of 200 ℃ for 20 seconds.
After the dicing tape was heated and contracted, a pickup test of the singulated semiconductor chips with Die bond sheets was carried out using an apparatus having a pickup mechanism (product name "Die bonder SPA-300", manufactured by shinkawa corporation). In the above pick-up test, the jack-up speed by the pin member was set to 1 mm/sec, and the jack-up amount was set to 2000 μm. The pickup test was performed after the adhesive layer was cured. The curing treatment was carried out by using an ultraviolet irradiation unit (high pressure mercury lamp, 70 mW/cm) incorporated in a chip separation apparatus 2 ) Irradiating 1000mJ/cm from the substrate layer side 2 By ultraviolet light.
The pick-up test was performed on 5 semiconductor chips with die bond pads. The evaluation criteria for the pickup property are as follows.
Excellent (good):
all of the 5 semiconductor chips with die bond pads can be picked up.
Good component: (slightly good)
3 or 4 of the 5 die-bonded semiconductor chips can be picked up.
X (poor):
more than 3 of the 5 die-bonded semiconductor chips cannot be picked up.
< evaluation of chip holding Performance (evaluation of chip lifting phenomenon suppression Performance) >
The dicing die-bonding films of the examples and comparative examples manufactured as described above were heated at a temperature of 50 to 80 ℃ and a bare wafer having a diameter of 300mm ("warped wafer" will be described in detail below) and a dicing ring were attached.
Next, the semiconductor wafer and the Die bond sheet were cut using Die separator DDS230 (manufactured by DISCO inc.), and the lift-off of the cut chip was evaluated. A bare wafer was cut into bare chips having a length of 10mm, a width of 10mm and a thickness of 0.055mm, and then ground to a thickness of 0.030mm.
As the bare wafer, a "warped wafer" produced as follows is used in order to more easily cause the chip lifting phenomenon.
[ production of warped wafer ]
In the production of a warped wafer, first, the following (a) to (f) were dissolved in methyl ethyl ketone to obtain a warp control composition having a solid content concentration of 20 mass%.
(a) Acrylic resin (manufactured by Nagase ChemteX Corporation, product name "SG-70L"): 5 parts by mass
(b) An epoxy resin (product name "JER828" manufactured by Mitsubishi chemical corporation): 5 parts by mass
(c) Phenol resin (product name "LDR8210" manufactured by mitsubishi chemical co., ltd.): 14 parts by mass
(d) Epoxy resin (product name "MEH-8005" made by Mitsubishi chemical corporation): 2 parts by mass of
(e) Spherical silica (ADMATECHS CO., manufactured by LTD., product name "SO-25R"): 53 parts by mass
(f) Phosphorus-based catalyst (TPP-K): 1 part by mass of
Next, the warpage-regulating composition was applied to the silicone-treated surface of a PET-based separator (thickness: 50 μm) as a release liner at a thickness of 25 μm using an applicator. The solvent was removed from the warpage-adjusting composition by performing a drying treatment at 130 ℃ for 2 minutes. Thus, a warpage-adjusting sheet was obtained in which a warpage-adjusting layer was laminated on the release liner.
Next, a bare wafer was attached to the side of the warpage-adjusting sheet on which the release liner was not laminated, using a laminator (model MRK-600, manufactured by MCK Co., ltd.) at 60 ℃ and 0.1MPa and 10 mm/s. Then, the resultant was put into an oven and heated at 175 ℃ for 1 hour to thermally cure the resin in the warpage-adjusting layer. Thus, a bare wafer warped as the warpage adjusting layer shrinks is obtained.
After the warpage-adjusting layer was shrunk, a wafer processing tape (manufactured by Nitto electric Co., ltd., product name "V-12SR 2") was attached to the warped bare wafer on the side where the warpage-adjusting layer was not laminated. Then, the dicing ring is fixed to the warped bare wafer via the wafer processing tape. Further, the warpage adjusting layer is removed from the warped bare wafer.
Grooves having a depth of 100 μm from the surface were formed in a lattice shape (groove width 20 μm) on the entire surface (hereinafter referred to as one surface) of the warped bare wafer from which the warpage adjusting layer was removed, using a dicing apparatus (model 6361, manufactured by DISCO corporation).
Next, a back-grinding tape is attached to one surface of the warped bare wafer, and the wafer-processing tape is removed from the other surface (the surface opposite to the one surface) of the warped bare wafer.
Next, the warped bare wafer was ground from the other surface side using a back grinder (model DGP8760, manufactured by DISCO corporation) so that the thickness of the warped bare wafer became 30 μm (0.030 mm). The wafer thus obtained was defined as a warped wafer.
[ method for evaluating Retention (suppression of chip lifting) ]
First, the bare wafer and the die bond were cut by a cold expanding unit under conditions of an expansion temperature of-15 ℃, an expansion speed of 200 mm/sec, and an expansion amount of 11mm, to obtain a semiconductor chip with a die bond.
Next, the expansion step was carried out at room temperature under conditions of an expansion rate of 1 mm/sec and an expansion amount of 7mm. Then, the dicing die bonding film at the boundary portion with the outer peripheral edge of the bare wafer was thermally shrunk under conditions of a heating temperature of 200 ℃, an air volume of 40L/min, a heating distance of 20mm, and a rotation speed of 3 °/sec while maintaining the spread state.
Next, the semiconductor chip with the die-bonding sheet was observed from the dicing tape side (polyolefin film side as a base material layer) while holding the dicing ring on the dicing die-bonding film. Then, the contact ratio of the semiconductor chip to the die bond sheet was calculated, and the holding property was evaluated.
Specifically, a photomicrograph was taken from the side of the cutting zone using the product name "VHX-6000" (manufactured by KEYENCE CORPORATION). Then, the photographed microscope photograph was subjected to image analysis using image analysis software (product name "ImageJ"). Further, the area of the portion of the semiconductor chip not floating from the chip bonding sheet was measured. The area of the semiconductor chip is calculated from the size of the semiconductor chip.
Then, the contact ratio of the semiconductor chip to the die bonding sheet is calculated from the area of the semiconductor chip and the area of the portion of the semiconductor chip not floating. The retention performance was evaluated based on the value of the contact ratio based on the following evaluation criteria.
O: the contact rate is more than 70 percent
And (delta): the contact rate is more than 60 percent and less than 70 percent
X: the contact rate is less than 60 percent
From the above evaluation results, it was confirmed that the dicing die-bonding film of the example was excellent in the pickup property as compared with the dicing die-bonding film of the comparative example.
The pressure-sensitive adhesive layer (pressure-sensitive adhesive tape) of the dicing die-bonding film of the example includes an acrylic copolymer having, as monomer units, at least an aliphatic alkyl (meth) acrylate unit having 12 or more carbon atoms in the alkyl moiety in the molecule and a crosslinkable group-containing (meth) acrylate unit,
the acrylic copolymer contains 10 to 85 mol% of the aliphatic alkyl (meth) acrylate unit and 15 to 35 mol% of the crosslinkable group-containing (meth) acrylate unit.
Further, the crosslinkable group-containing (meth) acrylate unit includes: a hydroxyl group-containing (meth) acrylate unit in which a hydroxyl group is bonded to an alkyl moiety having 4 or less carbon atoms, and a polymerizable (meth) acrylate unit having a radically polymerizable carbon-carbon double bond (polymerizable unsaturated double bond) in a side chain.
By using the dicing die-bonding film of the embodiment having such a configuration in manufacturing a semiconductor device, the semiconductor device can be manufactured efficiently. In the manufacture of semiconductor devices, in order to suppress the chip lifting phenomenon in the expansion process, the adhesive force between the adhesive layer and the chip bonding sheet is required to be relatively large. On the other hand, it is necessary to irradiate the pressure-sensitive adhesive layer with active energy rays such as ultraviolet rays before the pickup step, thereby to perform a curing treatment on the pressure-sensitive adhesive layer, and then to easily peel the die bonding sheet from the cured pressure-sensitive adhesive layer (to exert good pickup properties). In order to exert such contradictory properties, the pressure-sensitive adhesive layer contains an acrylic copolymer having, in the molecule, the above-mentioned mol% of a hydroxyl group-containing (meth) acrylate unit and a polymerizable (meth) acrylate unit as a crosslinkable group-containing (meth) acrylate unit.
When the acrylic copolymer contains the crosslinkable group-containing (meth) acrylate unit in the above mol%, the adhesive strength of the adhesive layer before curing is not excessively reduced, and when the acrylic copolymer contains the aliphatic alkyl (meth) acrylate unit in the above mol%, the adhesive strength of the adhesive layer after curing can be appropriately reduced.
Industrial applicability
The dicing die-bonding film of the present invention is suitably used as an auxiliary tool in manufacturing a semiconductor device (semiconductor integrated circuit), for example.

Claims (9)

1. An adhesive tape used as an adhesive layer of a dicing die-bonding film, the dicing die-bonding film comprising: the adhesive layer and a die bonding sheet superposed on the adhesive layer,
the adhesive tape comprises an acrylic copolymer having, as monomer units in a molecule, at least: an aliphatic alkyl (meth) acrylate unit having an alkyl moiety with 12 or more carbon atoms and a crosslinkable group-containing (meth) acrylate unit,
the acrylic copolymer contains 10 to 85 mol% of the aliphatic alkyl (meth) acrylate unit and 15 to 35 mol% of the crosslinkable group-containing (meth) acrylate unit.
2. The adhesive tape according to claim 1, wherein a part of the crosslinkable group-containing (meth) acrylate units in the acrylic copolymer has a radically polymerizable carbon-carbon double bond.
3. The adhesive tape according to claim 2, wherein the acrylic copolymer contains the crosslinkable group-containing (meth) acrylate unit having the radically polymerizable carbon-carbon double bond in the monomer unit in an amount of 8 mol% or more and 31 mol% or less.
4. The adhesive tape according to claim 1 or 2, wherein the proportion of the aliphatic alkyl (meth) acrylate unit in the monomer unit in the acrylic copolymer is 15 mol% or more and 40 mol% or less.
5. The adhesive tape according to claim 1 or 2, wherein the adhesive tape has a phase separation structure when a cross section is observed with an electron microscope.
6. A dicing die-bonding film comprising:
a dicing tape comprising a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive tape according to any one of claims 1 to 5 and a substrate layer superposed on the pressure-sensitive adhesive layer; and
a die bond sheet overlying the adhesive layer of the dicing tape.
7. The dicing die-bonding film according to claim 6, wherein a peeling force between the adhesive layer and the die-bonding sheet between the adhesive layer before curing by the active energy ray and a peeling force after curing (B) satisfy the following formula (1),
(A) /(B) >7.0 formula (1).
8. The dicing die-bonding film according to claim 7, wherein the (A)/(B) satisfies the following formula (2),
(A) /(B) >8.0 formula (2).
9. A method for manufacturing a semiconductor device, comprising:
a cutting step of cutting the wafer on which the circuit surface is formed into chips; and
a pickup process of peeling the die bonding sheet attached to the adhesive tape of the dicing die bonding film according to any one of claims 6 to 8 from the adhesive tape together with the die.
CN202210534957.9A 2021-05-19 2022-05-17 Adhesive tape, dicing die-bonding film, and method for manufacturing semiconductor device Pending CN115368841A (en)

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