CN112151434A

CN112151434A - Dicing tape and dicing die-bonding film

Info

Publication number: CN112151434A
Application number: CN202010582946.9A
Authority: CN
Inventors: 木村雄大; 每川英利; 武田公平; 植野大树; 中浦宏
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2019-06-28
Filing date: 2020-06-23
Publication date: 2020-12-29
Also published as: JP7430039B2; KR20210001954A; TW202113003A; JP2021009873A

Abstract

Provided are a dicing tape and a dicing die-bonding film. Provided is a dicing tape or the like comprising a base material layer and an adhesive layer superposed on the base material layer, wherein the dicing tape has a permanent deformation rate of 35% or more when stretched at 23 ℃ or-5 ℃.

Description

Dicing tape and dicing die-bonding film

Technical Field

The present invention relates to a dicing tape used for manufacturing, for example, a semiconductor integrated circuit, and a dicing die-bonding film provided with the dicing tape.

Background

Conventionally, dicing die-bonding films used for manufacturing semiconductor integrated circuits have been known. Such a dicing die-bonding film includes, for example, a dicing tape and a die-bonding layer laminated on the dicing tape and bonded to a wafer. The dicing tape has a base material layer and an adhesive layer in contact with the die bond layer. Such a dicing die-bonding film is used in the manufacture of a semiconductor integrated circuit, for example, as described below.

A method of manufacturing a semiconductor integrated circuit 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, the following steps: a mounting step of attaching a surface of the wafer on the opposite side to the circuit surface to the chip bonding layer and fixing the wafer to a dicing tape; a dicing step of dicing the wafer, which is attached to the dicing tape via the chip bonding layer, into small chips (Die); an expansion step of expanding the interval between the chips formed into the small pieces; a pickup step of peeling the Die bonding layer and the adhesive layer to take out the Die (Die) with the Die bonding layer attached thereto; and a Die bonding step of bonding the Die (Die) with the Die bonding layer attached thereto to an adherend. A semiconductor integrated circuit is manufactured through these steps.

In the above-described manufacturing method, the expanding step expands the distance (notch) between the adjacent chips (Die) by, for example, stretching the dicing tape in the radial direction at a low temperature such as a temperature below the freezing point in a state where the wafer is placed on the chip bonding layer overlapped on the dicing tape, and further stretching at room temperature. Thereafter, a part of the dicing tape, the tension of which is lowered by the stretching, is Heat-shrunk (Heat Shrink) to maintain the space (slit). Specifically, the dicing tape is heat-shrunk at a portion outside the portion overlapping the cut chip (Die), whereby the space (notch) can be maintained.

However, in the expanding step, the temporarily stretched dicing tape may contract due to elasticity, and the space (slit) may not be maintained. If the space (notch) cannot be maintained, the chip (Die) may float, and a trouble may occur in a subsequent pickup process. In order to prevent such a problem, it is highly desirable that the dicing tape has a performance of maintaining a cut after expansion.

In view of this, as a conventional dicing tape, for example, a dicing tape having a tensile load of 16 to 34N at an elongation of 10% under test conditions of a width of 25mm, a gauge length, and a distance between nip portions of 100mm, and a tensile speed of 300 mm/min is known (patent document 1).

The dicing tape described in patent document 1 has an adhesive force for suppressing the peeling of the wafer in the expanding step, has a performance capable of being cut into chips (Die), and can easily peel the Die bonding layer in the picking up step.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-155270

Disclosure of Invention

Problems to be solved by the invention

However, it cannot be said that sufficient studies have been made on dicing die-bonding films and dicing tapes that can maintain a satisfactory cut after expansion.

Accordingly, an object of the present invention is to provide a dicing tape and a dicing die-bonding film which can maintain a good cut after expansion.

Means for solving the problems

In order to solve the above problems, a dicing tape of the present invention includes a base material layer and a pressure-sensitive adhesive layer superposed on the base material layer, and is characterized in that the dicing tape has a permanent deformation ratio of 35% or more when stretched at 23 ℃.

According to the dicing tape having the above configuration, the incision can be maintained well after the expansion.

In order to solve the above problems, a dicing tape of the present invention includes a base material layer and a pressure-sensitive adhesive layer superposed on the base material layer, and is characterized in that the dicing tape has a permanent deformation rate of 35% or more when stretched at-5 ℃.

The dicing tape of the present invention preferably: the elastic modulus measured by the dynamic viscoelasticity tensile test is characterized in that the ratio (B/A) of the elastic modulus (B) at 60 ℃ to the elastic modulus (A) at 23 ℃ is 0.17 or more. This makes it possible to maintain the incision satisfactorily after the expansion and further the contraction with heat at room temperature.

The dicing tape of the present invention preferably: the elastic modulus measured by the dynamic viscoelasticity tensile test is 40MPa or more and 300MPa or less at 23 ℃, and the elastic modulus (B) is 8MPa or more and 100MPa or less at 60 ℃. This makes it possible to maintain the incision satisfactorily after the expansion and further the contraction with heat at room temperature.

The dicing tape of the present invention preferably: the elastic modulus (C) at 100 ℃ is 0.5MPa or more and 20MPa or less as measured by a dynamic viscoelasticity tensile test. This makes it possible to maintain the incision satisfactorily after the expansion and further the contraction with heat at room temperature.

The dicing die-bonding film of the present invention includes the dicing tape and the die-bonding layer laminated on the adhesive layer of the dicing tape.

ADVANTAGEOUS EFFECTS OF INVENTION

The dicing tape and the dicing die-bonding film of the present invention exert the following effects: the incision can be maintained well after expansion.

Drawings

FIG. 1: a cross-sectional view obtained by cutting the dicing die-bonding film of the present embodiment in the thickness direction.

FIG. 2A: a cross-sectional view schematically showing a case of half-cut processing in a manufacturing method of a semiconductor integrated circuit.

FIG. 2B: a cross-sectional view schematically showing a case of half-cut processing in a manufacturing method of a semiconductor integrated circuit.

FIG. 2C: a cross-sectional view schematically showing a case of half-cut processing in a manufacturing method of a semiconductor integrated circuit.

FIG. 2D: a cross-sectional view schematically showing a case of half-cut processing in a manufacturing method of a semiconductor integrated circuit.

FIG. 3A: a cross-sectional view schematically showing a case of a mounting process in a method of manufacturing a semiconductor integrated circuit.

FIG. 3B: a cross-sectional view schematically showing a case of a mounting process in a method of manufacturing a semiconductor integrated circuit.

FIG. 4A: a cross-sectional view schematically showing a case of an expanding process at a low temperature in a method of manufacturing a semiconductor integrated circuit.

FIG. 4B: a cross-sectional view schematically showing a case of an expanding process at a low temperature in a method of manufacturing a semiconductor integrated circuit.

FIG. 4C: a cross-sectional view schematically showing a case of an expanding process at a low temperature in a method of manufacturing a semiconductor integrated circuit.

FIG. 5A: the cross-sectional view schematically shows the case of an expansion process at normal temperature in a method for manufacturing a semiconductor integrated circuit.

FIG. 5B: the cross-sectional view schematically shows the case of an expansion process at normal temperature in a method for manufacturing a semiconductor integrated circuit.

FIG. 6: a cross-sectional view schematically showing a case of a pickup process in a method of manufacturing a semiconductor integrated circuit.

FIG. 7: a schematic diagram showing the concept of measuring the permanent deformation ratio.

Description of the reference numerals

1: cutting the chip bonding film,

10: a chip bonding layer,

20: a cutting belt,

21: a base material layer,

22: an adhesive layer.

Detailed Description

Hereinafter, an embodiment of a dicing die-bonding film and a dicing tape according to the present invention will be described with reference to the drawings.

The dicing die-bonding film 1 of the present embodiment includes: a dicing tape 20, and a die bonding layer 10 laminated on the adhesive layer 22 of the dicing tape 20 and bonded to a semiconductor wafer.

The dicing tape 20 of the present embodiment 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 one turn larger than that of a silicon wafer to be subjected to dicing and dicing.

The dicing tape 20 of the present embodiment includes a base material layer 21 and a pressure-sensitive adhesive layer 22 that overlaps the base material layer 21.

The dicing tape 20 of the present embodiment has a permanent set ratio of 35% or more when stretched at 23 ℃. Usually, the permanent deformation ratio at 23 ℃ under stretching is 100% or less.

The dicing tape 20 of the present embodiment has a permanent set ratio of 35% or more when stretched at-5 ℃. Usually, the permanent deformation ratio at-5 ℃ in stretching is 100% or less.

The dicing tape 20 of the present embodiment has any one of the above-described configurations, and therefore, can maintain a satisfactory cut after expansion.

The above-mentioned permanent set is a physical property when the dicing tape 20 is stretched at 23 ℃ by 100% or a physical property when the dicing tape 20 is stretched at-5 ℃ by 120%, and can be measured at each temperature according to the method described in examples. For example, "stretched 100%" means: stretching to 2 times the length before stretching.

The direction of the stretch-cut tape 20 may be either the MD direction or the TD direction, and the permanent set obtained by stretching in either direction may be the value described above. The average value of the measurement values obtained by 3 measurements was used as the above-mentioned permanent deformation ratio.

The above-mentioned permanent deformation ratio can be increased, for example, by increasing the mass ratio of the resin that is easily plastically deformed in the base material layer 21. On the other hand, the above-mentioned permanent deformation ratio can be reduced by, for example, increasing the mass ratio of the elastomer resin in the base material layer 21.

In addition, when the base material layer 21 is composed of a plurality of resin layers, the above-mentioned permanent deformation ratio can be adjusted by changing the relative thickness of at least 1 layer. For example, the above-described permanent deformation ratio can be increased by relatively increasing the thickness of the resin layer that is more easily plastically deformed.

In the dicing tape 20, the elastic modulus (a) at 23 ℃ is preferably 40MPa to 300MPa, and the elastic modulus (B) at 60 ℃ is preferably 8MPa to 100MPa, with respect to the elastic modulus measured by the dynamic viscoelasticity tensile test. This makes it possible to maintain the incision satisfactorily after the expansion and further the contraction with heat at room temperature.

The elastic modulus (A) at 23 ℃ is more preferably 50MPa or more. Further, 250MPa or less is more preferable.

The elastic modulus (B) at 60 ℃ is more preferably 10MPa or more. Further, 80MPa or less is more preferable.

In the dicing tape 20, the elastic modulus (C) at 100 ℃ is preferably 0.5MPa to 20MPa as measured by a dynamic viscoelasticity tensile test. By setting the elastic modulus (C) at 100 ℃ to 0.5MPa or more, the dicing tape 20 can be more sufficiently suppressed from being melted by heat shrinkage, damaged, and deformed. Thereby, a more uniform incision can be achieved. Further, by setting the elastic modulus (C) at 100 ℃ to 20MPa or less, the dicing tape 20 can be more sufficiently heat-shrunk by heat shrinkage. For this reason, by setting the elastic modulus (C) at 100 ℃ to the above value, the incision can be maintained more favorably after expansion at room temperature and further contraction by heating.

The elastic modulus (C) at 100 ℃ is more preferably 1MPa or more. Further, it is more preferably 10MPa or less.

The modulus of elasticity of the dicing tape 20 can be measured at each temperature according to the method described in examples. The elastic modulus is a value of tensile storage modulus measured by dynamic viscoelasticity measurement.

The elastic modulus (A, B, C) can be increased by, for example, increasing the mass ratio of the resin having a relatively high elastic modulus in the base material layer 21. On the other hand, the above elastic modulus can be reduced by, for example, reducing the mass ratio of the resin having a relatively high elastic modulus.

In addition, when the base material layer 21 is composed of a plurality of resin layers, the above-mentioned elastic modulus can be adjusted by changing the relative thickness of at least 1 layer. For example, the above elastic modulus may be increased by relatively increasing the thickness of the resin layer having a relatively high elastic modulus.

In the dicing tape, the ratio (B/A) of the elastic modulus (B) at 60 ℃ to the elastic modulus (A) at 23 ℃ is preferably 0.17 or more. This makes it possible to maintain the incision satisfactorily after the expansion and further the contraction with heat at room temperature.

The above ratio (B/A) is more preferably 0.18 or more, and still more preferably 0.20 or more.

The ratio (B/a) may be 0.5 or less and may be 0.3 or less.

The substrate layer 21 may have a single-layer structure or a laminated structure. The base material layer 21 preferably has a laminated structure in that the elastic modulus and the permanent deformation ratio of the base material layer 21 can be adjusted relatively easily by changing the type of resin contained in each layer or the thickness ratio of the layers.

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 substrate 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) acrylate (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 fibers); 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 two or more kinds.

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, 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 employed. Further, coating treatment with a coating agent such as an anchor coating agent, a primer, or an adhesive may be performed.

The base material layer 21 is preferably composed of a plurality of layers, more preferably composed of at least 3 layers, and further preferably composed of 3 layers.

By providing the substrate layer 21 with a multilayer laminated structure (for example, a 3-layer structure), there is an advantage that the elastic modulus and the permanent deformation ratio can be adjusted relatively easily by changing the ratio of the layer thicknesses of the respective layers.

The base layer 21 having a 3-layer structure preferably includes 2 nonelastomeric layers (X, X) each formed of a nonelastomer, and an elastomeric layer (Y) (X layer/Y layer/X layer) disposed between the 2 nonelastomeric layers and formed of an elastomer.

The elastomer layer is generally formed of a polymer material exhibiting rubber elasticity at room temperature (23 ℃). The elastomer layer has a set of less than 35% when measured at 23 ℃ in the same manner as the set of the above-described measurements. On the other hand, the non-elastic body layer is a layer other than an elastic body.

Each layer of such an elastomer having a laminated structure of 3 layers is generally formed of a resin. The elastomer having a laminated structure of 3 layers is produced by, for example, coextrusion molding, and the 3 layers are integrated.

The non-elastic body layer disposed on the outer side has a melting point of, for example, 100 ℃ to 130 ℃. The non-elastic layer preferably has a molecular weight distribution dispersity (mass average molecular weight/number average molecular weight) of 3 or less when GPC measurement is performed on the resin constituting the non-elastic layer.

The non-elastomeric layer (X) may comprise Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), polypropylene, etc. Examples of the polypropylene include homopolymers (homo-polypropylene), copolymers such as random polypropylene and block polypropylene. The polypropylene may be a metallocene polypropylene synthesized using a metallocene catalyst. The non-elastomeric layer (X) preferably comprises metallocene polypropylene.

On the other hand, the elastomer layer (Y) preferably contains an ethylene-vinyl acetate copolymer (EVA) or an α -olefin-based thermoplastic elastomer. The α -olefin-based thermoplastic elastomer includes homopolymers of α -olefins and copolymers of two or more α -olefins.

The thickness of the base material layer 21 may be 60 μm or more and 160 μm or less. The thickness of the base material layer 21 is preferably 60 μm or more and 120 μm or less, and more preferably 80 μm or more and 100 μm or less. The thickness is an average value of measured values obtained by measuring the thicknesses at 5 positions selected at random by a direct-reading thickness meter.

The ratio (X layer/Y layer) of the thickness of 1 layer (X layer) to the thickness of the elastomer layer (Y layer) in the non-elastomer layer is preferably in the range of 0.05 to 0.25.

The back surface side (the side not overlapping the pressure-sensitive adhesive layer 22) of the base material layer 21 may be subjected to a release treatment with a release agent (release agent) such as a silicone resin or a fluorine resin, for example, to impart releasability.

The base layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like, in view of being able to supply active energy rays such as ultraviolet rays to the pressure-sensitive adhesive layer 22 from the back surface side.

The dicing tape 20 of the present embodiment 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 on which the base material layer 21 is not stacked) in a state before use. When the die-bonding layer 10 having a smaller area than the adhesive layer 22 is disposed so as to be accommodated in the adhesive layer 22, the release sheet is disposed so as to cover both the adhesive layer 22 and the die-bonding layer 10. The release sheet is used to protect the adhesive layer 22, and is peeled off before the die-bonding layer 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.

As the release sheet, for example, a film made of a fluorine-based polymer such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, a copolymer of tetrafluoroethylene and hexafluoropropylene, and a copolymer of chlorofluoroethylene and vinylidene fluoride; films made of polyolefins such as polyethylene and polypropylene; and films made of polyesters such as polyethylene terephthalate (PET).

As the release sheet, for example, a plastic film or paper coated with a release agent such as a fluorine-based release agent or a long chain alkyl acrylate-based release agent can be used.

The release sheet may be used as a support material for supporting the adhesive layer 22. The release sheet is particularly suitable for use when the pressure-sensitive adhesive layer 22 is superposed on the base layer 21. Specifically, the pressure-sensitive adhesive layer 22 may be superposed on the base layer 21 by superposing the pressure-sensitive adhesive layer 22 on the base 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 to superpose the pressure-sensitive adhesive layer 22 on the base layer 21.

In the present embodiment, the adhesive layer 22 contains, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator.

The adhesive layer 22 preferably has a thickness of 3 μm or more and 200 μm or less. The shape and size of the adhesive layer 22 are generally the same as those of the base material layer 21.

In the dicing tape 20 of the present embodiment, the ratio of the thickness of the pressure-sensitive adhesive layer 22 to the total thickness of the dicing tape 20 may be 1% or more and 15% or less.

The acrylic polymer has at least a constituent unit of an alkyl (meth) acrylate, a constituent unit of a hydroxyl group-containing (meth) acrylate, and a constituent unit of a polymerizable group-containing (meth) acrylate in the molecule. The constituent unit is a unit constituting the main chain of the acrylic polymer. Each side chain in the acrylic polymer is contained in each constituent unit constituting the main chain.

In the present specification, the expression "(meth) acrylate" means at least one of methacrylate and acrylate. Likewise, the expression "(meth) acrylic acid" means at least one of methacrylic acid and acrylic acid.

In the acrylic polymer contained in the pressure-sensitive adhesive layer 22, the above-mentioned constituent unit may be used¹H-NMR、¹³NMR analysis such as C-NMR, thermal decomposition GC/MS analysis, infrared spectroscopy, and the like. The molar ratio of the above-mentioned constituent unit in the acrylic polymer can be usually calculated from the amount of blending (charged amount) in the polymerization of the acrylic polymer.

The constituent unit of the alkyl (meth) acrylate is derived from an alkyl (meth) acrylate monomer. In other words, the molecular structure of the alkyl (meth) acrylate monomer after the polymerization reaction is a constituent unit of the alkyl (meth) acrylate. The expression "alkyl" denotes a hydrocarbon moiety forming an ester bond with (meth) acrylic acid.

The hydrocarbon of the alkyl portion in the constituent unit of the alkyl (meth) acrylate may be a saturated hydrocarbon or an unsaturated hydrocarbon.

The alkyl moiety preferably does not contain a polar group containing oxygen (O), nitrogen (N), or the like. This can suppress an extreme increase in polarity of the alkyl polymer. Therefore, the adhesive layer 22 can be suppressed from having excessive affinity for the chip bonding layer 10. The dicing tape 20 can thereby be more favorably peeled off from the chip bonding layer 10. The number of carbons in the alkyl moiety may be 6 or more and 10 or less.

Examples of the constituent unit of the alkyl (meth) acrylate include various constituent units such as hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and decyl (meth) acrylate.

The acrylic polymer has a constituent unit of a hydroxyl group-containing (meth) acrylate, and the hydroxyl group of the constituent unit is easily reacted with an isocyanate group.

By allowing an acrylic polymer having a constituent unit of a hydroxyl group-containing (meth) acrylate and an isocyanate compound to coexist in the pressure-sensitive adhesive layer 22 in advance, the pressure-sensitive adhesive layer 22 can be appropriately cured. Therefore, the acrylic polymer can be sufficiently gelled. Thereby, the adhesive layer 22 can maintain the shape and exert the adhesive property.

The constituent unit of the hydroxyl group-containing (meth) acrylate is preferably a constituent unit of a hydroxyl group-containing C2-C4 alkyl (meth) acrylate. The expression "C2-C4 alkyl" denotes the number of carbon atoms of the hydrocarbon moiety which forms an ester bond with (meth) acrylic acid. In other words, the hydroxyl group-containing C2 to C4 alkyl (meth) acrylate monomer is a monomer obtained by forming an ester bond between (meth) acrylic acid and an alcohol having 2 to 4 carbon atoms (usually 2-membered alcohol).

The hydrocarbon moiety of the C2-C4 alkyl group is typically a saturated hydrocarbon. For example, the hydrocarbon moiety of the C2-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 constituent unit of the hydroxyl group-containing C2-C4 alkyl (meth) acrylate include: and a hydroxybutyl (meth) acrylate such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxy-n-butyl (meth) acrylate or hydroxyisobutyl (meth) acrylate. In the constitutional unit of hydroxybutyl (meth) acrylate, a hydroxyl group (-OH group) may be bonded to a carbon (C) at the end of a hydrocarbon moiety, or may be bonded to a carbon (C) other than the end of a hydrocarbon moiety.

The acrylic polymer contains a constituent unit of a polymerizable group-containing (meth) acrylate having a polymerizable unsaturated double bond in a side chain.

By including the acrylic polymer with the constituent unit of the polymerizable group-containing (meth) acrylate, the pressure-sensitive adhesive layer 22 can be cured by irradiation with active energy rays (ultraviolet rays or the like) before the pickup step. Specifically, by irradiating active energy rays such as ultraviolet rays, radicals are generated from the photopolymerization initiator, and the acrylic polymers can be crosslinked by the action of the radicals. Thus, the adhesive force of the pressure-sensitive adhesive layer 22 before irradiation can be reduced by irradiation. Further, the chip bonding layer 10 can be favorably peeled from the adhesive layer 22.

As the active energy ray, ultraviolet rays, radiation rays, and electron beams can be used.

Specifically, the constituent unit of the polymerizable group-containing (meth) acrylate may have the following molecular structure: a molecular structure obtained by forming a urethane bond between an isocyanate group of an isocyanate group-containing (meth) acrylate monomer and a hydroxyl group in the constituent unit of the hydroxyl group-containing (meth) acrylate.

The constituent unit of the polymerizable group-containing (meth) acrylate having a polymerizable group can be prepared after polymerization of the acrylic polymer. For example, the above-mentioned polymerizable group-containing (meth) acrylate constituent unit can be obtained by copolymerizing an alkyl (meth) acrylate monomer and a hydroxyl group-containing (meth) acrylate monomer, and then subjecting a part of the hydroxyl groups of the hydroxyl group-containing (meth) acrylate constituent unit and the isocyanate groups of the isocyanate group-containing polymerizable monomer to a urethanization reaction.

The isocyanate group-containing (meth) acrylate monomer described above preferably has 1 isocyanate group and 1 (meth) acryloyl group in the molecule. Examples of the monomer include: 2-isocyanatoethyl (meth) acrylate.

The adhesive layer 22 of the dicing tape 20 in this embodiment further contains an isocyanate compound. A part of the isocyanate compound may be in a state after the reaction by a urethanization reaction or the like.

The isocyanate compound has a plurality of isocyanate groups in a molecule. By having a plurality of isocyanate groups in a molecule, the acrylic polymer in the pressure-sensitive adhesive layer 22 can be cross-linked. Specifically, the crosslinking reaction by the isocyanate compound can be performed by reacting one isocyanate group of the isocyanate compound with a hydroxyl group of the acrylic polymer and reacting the other isocyanate group with a hydroxyl group of the other acrylic polymer.

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: a polyisocyanate obtained by reacting an excess of the above 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 two 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. The reaction speed of the isocyanate group of the reaction product of the aromatic diisocyanate is relatively slow, and thus the adhesive layer 22 including the reaction product can suppress excessive curing. The isocyanate compound is preferably an isocyanate compound having 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 acrylic polymers can be cross-linked when thermal energy or light 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 between polymerizable groups in an acrylic polymer having a constituent unit of a polymerizable group-containing (meth) acrylate. This can reduce the adhesive force of the adhesive layer 22, and the die-bonding layer 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 can be used. As the polymerization initiator, a general commercially available product can be used.

The adhesive layer 22 may also contain other components in addition to those described above. Examples of other components include: tackifiers, plasticizers, fillers, antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, antistatic agents, surfactants, light strippers, and the like. The kind and amount of the other ingredients may be appropriately selected depending on the purpose.

Next, the dicing die-bonding film 1 of the present embodiment will be described in detail.

The dicing die-bonding film 1 of the present embodiment includes: the dicing tape 20 described above, and the die bonding layer 10 laminated on the adhesive layer 22 of the dicing tape 20. The die bonding layer 10 is bonded to a semiconductor wafer in the manufacture of a semiconductor integrated circuit.

The chip bonding layer 10 may include at least one of a thermosetting resin and a thermoplastic resin. The chip bonding layer 10 preferably contains a thermosetting resin and a thermoplastic resin.

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. The thermosetting resin may be used alone in 1 kind or in two or more kinds. An epoxy resin is preferable as the thermosetting resin in that it contains less ionic impurities and the like that may cause corrosion of the semiconductor chip to be die-bonded. As the curing agent for the epoxy resin, a phenol resin is preferable.

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, trihydroxyphenyl methane type, tetrahydroxyphenyl ethane type, hydantoin type, triglycidyl isocyanurate type, or glycidyl amine type.

The phenolic resin can function as a curing agent for the epoxy resin. Examples of the phenolic resin include: and polyoxystyrenes such as novolak-type phenol resins, resol-type phenol resins, and poly-p-oxystyrene.

Examples of the novolak phenol resin include: phenol novolac resins, phenol aralkyl resins, cresol novolac resins, tert-butylphenol novolac resins, nonylphenol novolac resins, and the like.

The phenolic resin may be used alone in 1 kind or in two or more kinds.

In the chip bonding layer 10, the hydroxyl group of the phenol resin is preferably 0.5 equivalent to 2.0 equivalents, more preferably 0.7 equivalent to 1.5 equivalents, with respect to 1 equivalent of the epoxy group of the epoxy resin. This makes it possible to sufficiently perform the curing reaction of the epoxy resin and the phenol resin.

When the chip bonding layer 10 contains a thermosetting resin, the content of the thermosetting resin in the chip bonding layer 10 is preferably 5% by mass or more and 60% by mass or less, and more preferably 10% by mass or more and 50% by mass or less, with respect to the total mass of the chip bonding layer 10. Thereby, the chip bonding layer 10 can appropriately exhibit a function as a thermosetting adhesive.

Examples of the thermoplastic resin that can be contained in the chip bonding layer 10 include: natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer, a polybutadiene resin, a polycarbonate resin, a thermoplastic polyimide resin, a polyamide resin such as 6-nylon and 6, 6-nylon (trade name), a phenoxy resin, an acrylic resin, a saturated polyester resin such as PET and PBT, a polyamideimide resin, a fluororesin, and the like.

The thermoplastic resin is preferably an acrylic resin in that it has a small amount of ionic impurities and high heat resistance, and can further secure the adhesiveness of the chip bonding layer 10.

The thermoplastic resin may be used alone in 1 kind or in two or more kinds.

The acrylic resin is preferably a polymer having a maximum number of alkyl (meth) acrylate constituent units in terms of mass ratio among constituent units in the molecule. Examples of the alkyl (meth) acrylate include: C2-C4 alkyl (meth) acrylates.

The acrylic resin may further contain a constituent unit derived from another monomer component copolymerizable with the alkyl (meth) acrylate monomer.

Examples of the other monomer components include: carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, functional group-containing monomers such as acrylamide and acrylonitrile, and other various polyfunctional monomers.

From the viewpoint of exerting a higher cohesive force in the die-bonding layer 10, the acrylic resin is preferably a copolymer of an alkyl (meth) acrylate (particularly, an alkyl (meth) acrylate having 4 or less carbon atoms in the alkyl moiety) and a carboxyl group-containing monomer and a nitrogen atom-containing monomer and a polyfunctional monomer (particularly, a polyglycidyl-based polyfunctional monomer), and more preferably a copolymer of ethyl acrylate and butyl acrylate and acrylic acid and acrylonitrile and polyglycidyl (meth) acrylate.

The glass transition temperature (Tg) of the acrylic resin is preferably 5 ℃ to 35 ℃, more preferably 10 ℃ to 30 ℃, in order to easily set the elasticity and viscosity of the chip bonding layer 10 within desired ranges.

When the chip bonding layer 10 contains a thermosetting resin and a thermoplastic resin, the content ratio of the thermoplastic resin in the chip bonding layer 10 is preferably 30% by mass or more and 70% by mass or less, more preferably 40% by mass or more and 60% by mass or less, and further preferably 45% by mass or more and 55% by mass or less, with respect to the total mass of organic components other than the filler (for example, the thermosetting resin, the thermoplastic resin, a curing catalyst, and the like, a silane coupling agent, and a dye). The elasticity and viscosity of the chip bonding layer 10 can be adjusted by changing the content ratio of the thermosetting resin.

When the thermoplastic resin of the chip bonding layer 10 has a thermosetting functional group, an acrylic resin having a thermosetting functional group can be used as the thermoplastic resin, for example. The thermosetting functional group-containing acrylic resin preferably contains a constituent unit derived from an alkyl (meth) acrylate in the largest mass ratio in the molecule. Examples of the alkyl (meth) acrylate include: the (meth) acrylic acid alkyl esters exemplified above.

On the other hand, examples of the thermosetting functional group in the thermosetting functional group-containing acrylic resin include: glycidyl, carboxyl, hydroxyl, isocyanate, and the like.

The chip bonding layer 10 preferably contains a thermosetting functional group-containing acrylic resin and a curing agent. Examples of the curing agent include those exemplified as the curing agent that can be contained in the adhesive layer 22. When the thermosetting functional group in the thermosetting functional group-containing acrylic resin is a glycidyl group, a compound having a plurality of phenol structures is preferably used as the curing agent. As the curing agent, for example, various phenolic resins as described above can be used.

The chip bonding layer 10 preferably contains a filler. By changing the amount of the filler in the chip bonding layer 10, the elasticity and viscosity of the chip bonding layer 10 can be adjusted more easily. Further, physical properties such as electrical conductivity, thermal conductivity, and elastic modulus of the chip bonding layer 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 including 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, and amorphous silica. Examples of the material of the inorganic filler include simple metals such as aluminum, gold, silver, copper, and nickel, and alloys thereof. Can be fillers such as aluminum borate whisker, amorphous carbon black, graphite and the like. The filler may be in the form of a sphere, needle, or sheet. As the filler, only 1 kind or two or more kinds of the above may be used.

The average particle diameter of the filler is preferably 0.005 μm or more and 10 μm or less, more preferably 0.005 μm or more and 1 μm or less. By setting the average particle size to 0.005 μm or more, wettability and adhesiveness to an adherend such as a semiconductor wafer are further improved. By setting the average particle diameter to 10 μm or less, the properties of the filler to be added can be more sufficiently exhibited, and the heat resistance of the chip bonding layer 10 can be further exhibited. The average particle diameter of the filler can be determined, for example, by using a photometric particle size distribution meter (e.g., product name "LA-910", HORIBA, manufactured by Ltd.).

When the chip bonding layer 10 contains a filler, the content of the filler is preferably 30 mass% or more and 70 mass% or less, more preferably 40 mass% or more and 60 mass% or less, and still more preferably 42 mass% or more and 55 mass% or less, with respect to the total mass of the chip bonding layer 10.

The chip bonding layer 10 may contain other components as necessary. Examples of the other components include: curing catalysts, flame retardants, silane coupling agents, ion scavengers, dyes, and the like.

Examples of the flame retardant include: antimony trioxide, antimony pentoxide, brominated epoxy resins, and the like.

Examples of the silane coupling agent include: beta- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropylmethyldiethoxysilane, etc.

Examples of the ion scavenger include: hydrotalcites, bismuth hydroxide, benzotriazole, and the like.

As the other additives, only 1 kind or two or more kinds may be used.

The chip bonding layer 10 preferably contains a thermoplastic resin (particularly an acrylic resin), a thermosetting resin, and a filler, in view of easy adjustment of elasticity and viscosity.

In the chip bonding layer 10, the content ratio of the thermoplastic resin such as an acrylic resin to the total mass of the organic components excluding the filler is preferably 30 mass% or more and 70 mass% or less, more preferably 40 mass% or more and 60 mass% or less, and further preferably 45 mass% or more and 55 mass% or less.

The content ratio of the filler is preferably 30 mass% or more and 70 mass% or less, more preferably 40 mass% or more and 60 mass% or less, and further preferably 42 mass% or more and 55 mass% or less with respect to the total mass of the chip bonding layer 10.

The thickness of the chip bonding layer 10 is not particularly limited, and is, for example, 1 μm or more and 200 μm or less. The upper limit of the thickness is preferably 100 μm, more preferably 80 μm. The lower limit of the thickness is preferably 3 μm, more preferably 5 μm. When the die bonding layer 10 is a laminate, the thickness is the total thickness of the laminate.

The glass transition temperature (Tg) of the chip bonding layer 10 is preferably 0 ℃ or higher, and more preferably 10 ℃ or higher. By setting the glass transition temperature to 0 ℃ or higher, the chip bonding layer 10 can be easily cleaved by cold spreading. The upper limit of the glass transition temperature of the chip bonding layer 10 is, for example, 100 ℃.

As shown in fig. 1, the chip bonding layer 10 may have a single-layer structure, for example. In the present specification, a single layer means a layer having only the same composition. The form in which a plurality of layers made of the same composition are stacked is also a single layer.

On the other hand, the chip bonding layer 10 may have a multilayer structure in which layers each formed of two or more different compositions are stacked, for example.

The dicing die-bonding film 1 of the present embodiment is used by, for example, irradiating ultraviolet rays to cure the adhesive layer 22. Specifically, in a state where a die bonding layer 10 having a semiconductor wafer bonded to one surface thereof and an adhesive layer 22 bonded to the other surface of the die bonding layer 10 are laminated, at least the adhesive layer 22 is irradiated with ultraviolet light 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 that have passed 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-bonding layer 10 (in a state where the semiconductor wafer is bonded) can be peeled off from the adhesive layer 22 relatively easily after irradiation.

The dicing die-bonding film 1 of the present embodiment may be provided with a release sheet covering one surface of the die-bonding layer 10 (the surface of the die-bonding layer 10 on which the adhesive layer 22 is not superimposed) in a state before use. The release sheet is used for protecting the chip bonding layer 10, and is peeled off immediately before an adherend (e.g., a semiconductor wafer) is attached to the chip bonding layer 10.

As the release sheet, the same release sheet as the above-described release sheet can be used. The release sheet can be used as a support material for supporting the chip bonding layer 10. A release sheet is suitably used when the die-bonding layer 10 is superposed on the adhesive layer 22. Specifically, the chip bonding layer 10 may be superposed on the adhesive layer 22 by superposing the chip bonding layer 10 on the adhesive layer 22 in a state where the release sheet is laminated on the chip bonding layer 10, and then peeling (transferring) the release sheet.

Since the dicing die-bonding film 1 of the present embodiment is configured as described above, the cut can be maintained well after the expansion.

Next, a method for manufacturing the dicing tape 20 and the dicing die-bonding film 1 according to the present embodiment will be described.

The method for manufacturing the dicing die-bonding film 1 of the present embodiment includes:

a step of manufacturing a dicing tape 20 (a method of manufacturing a dicing tape), and a step of manufacturing a dicing die-bonding film 1 by superposing a die-bonding layer 10 on the manufactured dicing tape 20.

The method for manufacturing a dicing tape (step of manufacturing a dicing tape) includes:

a synthesis step for synthesizing an acrylic polymer;

a pressure-sensitive adhesive layer production step of producing a pressure-sensitive adhesive layer 22 by volatilizing a solvent from a pressure-sensitive adhesive composition containing the acrylic polymer, the isocyanate compound, the polymerization initiator, the solvent, and other components added as appropriate according to the purpose; and

and a laminating step of laminating the base material layer 21 and the pressure-sensitive adhesive layer 22 by bonding the pressure-sensitive adhesive layer 22 and the base material layer 21.

In the synthesis step, for example, a C9 to C11 alkyl (meth) acrylate monomer and a hydroxyl group-containing (meth) acrylate monomer are subjected to radical polymerization to synthesize an acrylic polymer intermediate.

The radical polymerization can be carried out by a conventional method. For example, the acrylic polymer intermediate can be synthesized by dissolving the above-mentioned monomers in a solvent and stirring them while heating, and adding a polymerization initiator. In order to adjust the molecular weight of the acrylic polymer, the polymerization may be carried out in the presence of a chain transfer agent.

Next, a part of the hydroxyl groups of the constituent units of the hydroxyl group-containing (meth) acrylate contained in the acrylic polymer intermediate and the isocyanate groups of the isocyanate group-containing polymerizable monomer are bonded by a urethanization reaction. Thus, a part of the constituent unit of the hydroxyl group-containing (meth) acrylate forms a constituent unit of the polymerizable group-containing (meth) acrylate.

The carbamation reaction can be carried out by a conventional method. For example, the acrylic polymer intermediate and the isocyanate group-containing polymerizable monomer are stirred in the presence of a solvent and a urethane-forming catalyst while heating. This enables the isocyanate group of the isocyanate group-containing polymerizable monomer to form a urethane bond with a part of the hydroxyl group of the acrylic polymer intermediate.

In the pressure-sensitive adhesive layer producing step, for example, an acrylic polymer, 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 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 composition is subjected to desolvation treatment, curing treatment, or the like, whereby the applied adhesive composition is cured to produce the adhesive layer 22.

In the laminating step, the pressure-sensitive adhesive layer 22 and the base material layer 21 are laminated in a state of being laminated on the release sheet. The release sheet may be in a state of being overlapped with the adhesive layer 22 until the use.

In order to promote the reaction between the crosslinking agent and the acrylic polymer and the reaction between the crosslinking agent and the surface portion of the base layer 21, a curing step may be performed at 50 ℃ for 48 hours after the laminating step.

The substrate layer 21 may be a commercially available film or the like, or may be formed by a usual method. Examples of the film forming method include: a calendering film-forming method, a casting method in an organic solvent, a inflation extrusion method in a closed system, a T-die extrusion method, a dry lamination method, and the like. In addition, a coextrusion molding method may be employed.

Through these steps, the dicing tape 20 can be manufactured.

The method for manufacturing a dicing die-bonding film (step of manufacturing a dicing die-bonding film) includes the steps of:

a resin composition preparation step of preparing a resin composition for forming the chip bonding layer 10;

a chip bonding layer production step of producing a chip bonding layer 10 from the resin composition; and

and an attaching step of attaching the chip bonding layer 10 to the adhesive layer 22 of the dicing tape 20 obtained in the above-described manner.

In the resin composition preparation step, for example, an epoxy resin, a curing catalyst for an epoxy resin, an acrylic resin, a phenol resin, a solvent, and the like are mixed and each resin is dissolved in a solvent to prepare a resin composition. The viscosity of the composition can be adjusted by varying the amount of solvent. As these resins, commercially available products can be used.

In the chip bonding layer formation step, for example, the resin composition prepared in the above manner is applied to a release sheet. The coating method is not particularly limited, and for example, a general coating method such as roll coating, screen coating, gravure coating, or the like can be used. Next, the applied composition is cured by desolvation treatment, curing treatment, or the like as necessary, thereby producing the chip bonding layer 10.

In the attaching step, the release sheet is peeled off from each of the pressure-sensitive adhesive layer 22 of the dicing tape 20 and the die-bonding layer 10, and the die-bonding layer 10 and the pressure-sensitive adhesive layer 12 are attached to each other so as to be in direct contact with each other. For example, the bonding may be performed by pressure bonding. 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, and more preferably 1kgf/cm or more and 10kgf/cm or less.

The dicing die-bonding film 1 manufactured as described above is used as an auxiliary tool for manufacturing a semiconductor integrated circuit, for example. Specific examples of the use thereof will be described below.

A method of manufacturing a semiconductor integrated circuit generally includes a step of cutting out and assembling chips from a semiconductor wafer on which a circuit surface is formed.

This step includes, for example, the following steps: a half-cut step of forming a groove in a semiconductor wafer by processing the semiconductor wafer into chips (Die) by a dicing process, and grinding the semiconductor wafer 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 subjected to the half dicing process to the die bonding layer 10, and fixing the semiconductor wafer to the dicing tape 20; an expanding step of expanding the interval between the semiconductor chips subjected to the half-cut processing; a pickup step of peeling the chip bonding layer 10 and the adhesive layer 22 and taking out the semiconductor chip (Die) in a state where the chip bonding layer 10 is attached; and a Die bonding step of bonding the semiconductor chip (Die) with the Die bonding layer 10 attached thereto to an adherend. In performing these steps, the dicing tape (dicing die-bonding film) of the present embodiment is used as a manufacturing aid.

In the half-cut step, as shown in fig. 2A to 2D, a half-cut process for cutting the semiconductor integrated circuit into chips (Die) is performed. Specifically, the wafer processing tape T is attached to the surface of the semiconductor wafer opposite to the circuit surface. Further, the dicing ring R is attached to the wafer processing tape T. The dividing grooves are formed in a state where the wafer processing tape T is attached. A back grinding tape G is attached to the surface having the grooves formed thereon, and the wafer processing tape T attached first is peeled off. Grinding is performed with the back grinding tape G attached until the semiconductor wafer has a predetermined thickness.

In the mounting step, as shown in fig. 3A to 3B, after the dicing ring R is mounted on the adhesive layer 22 of the dicing tape 20, the semiconductor wafer subjected to the half-dicing process is attached to the exposed surface of the die bonding layer 10. The back grinding tape G is then peeled off from the semiconductor wafer.

In the expanding step, as shown in fig. 4A to 4C, the dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and then fixed to the holding tool H of the expanding device. The cut die-bonding film 1 is stretched and spread in the planar direction by lifting up a lifting member U provided in the spreading device from below the cut die-bonding film 1. Thus, the semi-diced semiconductor wafer is cut under a specific temperature condition. The temperature is, for example, -20 to 5 ℃, preferably-15 to 0 ℃, and more preferably-10 to-5 ℃. The expansion state is released by lowering the jack-up member U (the cold expansion process up to this point).

Further, in the expanding step, as shown in fig. 5A to 5B, the dicing tape 20 is stretched under a higher temperature condition to expand the area. Thereby, the adjacent semiconductor chips to be cut are separated in the surface direction of the thin film surface, and the interval is further widened (room temperature expansion step).

Here, a part of the dicing tape 20 is thermally contracted (heat-contracted) in order to maintain the interval between the semiconductor wafers that have been cut (diced). Specifically, the dicing tape 20 is fixed by thermally shrinking (heat shrinking) a portion outside a portion overlapping the semiconductor wafer.

In the pickup step, as shown in fig. 6, the semiconductor chip with the die bonding layer 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 to be picked up via the dicing tape 20. The semiconductor chip lifted up is held by an adsorption jig J.

In the die bonding step, the semiconductor chip with the die bonding layer 10 attached thereto is bonded to an adherend.

The matters disclosed in the present specification include the following matters.

(1)

A dicing tape comprising a base material layer and an adhesive layer superposed on the base material layer, wherein the dicing tape has a permanent deformation ratio of 35% or more when stretched at 23 ℃.

(2)

A dicing tape comprising a base material layer and an adhesive layer superposed on the base material layer, wherein the dicing tape has a permanent deformation ratio of 35% or more when stretched at-5 ℃.

(3)

The dicing tape according to the above (1) or (2), wherein, with respect to the elastic modulus measured by a dynamic viscoelasticity tensile test,

the ratio (B/A) of the elastic modulus (B) at 60 ℃ to the elastic modulus (A) at 23 ℃ is 0.17 to 0.50.

(4)

The dicing tape according to any one of the above (1) to (3), wherein regarding the elastic modulus measured by a dynamic viscoelasticity tensile test,

an elastic modulus (A) at 23 ℃ of 40 to 300MPa,

an elastic modulus (B) at 60 ℃ of 8MPa or more and 100MPa or less.

(5)

The dicing tape according to any one of the above (1) to (4), wherein regarding the elastic modulus measured by a dynamic viscoelasticity tensile test,

an elastic modulus (C) at 100 ℃ of 0.5MPa or more and 20MPa or less.

(6)

The dicing tape according to any one of the above (1) to (5), wherein the base material layer is composed of a plurality of layers.

(7)

The dicing tape according to any one of the above (1) to (6), wherein the base layer is composed of at least 3 layers, and has 2 nonelastomeric layers formed of a nonelastomer, and an elastomeric layer formed of an elastomer and disposed between the 2 nonelastomeric layers.

(8)

The dicing tape according to any one of the above (1) to (7), wherein the non-elastic layer contains polypropylene.

(9)

The dicing tape according to any one of the above (1) to (8), wherein the elastomer layer contains at least one of an ethylene-vinyl acetate copolymer (EVA) or an α -olefin-based thermoplastic elastomer.

(10)

The dicing tape according to any one of the above (7) to (9), wherein a ratio (X layer/Y layer) of a thickness of 1 layer (X layer) in the non-elastic body layer to a thickness of the elastic body layer (Y layer) is in a range of 0.05 or more and 0.25 or less.

(11)

The dicing tape according to any one of the above (1) to (10), wherein the thickness of the base material layer is 60 μm or more and 160 μm or less.

(12)

The dicing tape according to any one of the above (1) to (11), wherein the pressure-sensitive adhesive layer contains an acrylic polymer having, in a molecule, at least: a constituent unit of an alkyl (meth) acrylate, a constituent unit of a hydroxyl group-containing (meth) acrylate, and a constituent unit of a polymerizable group-containing (meth) acrylate.

(13)

The dicing tape according to the above (12), wherein the adhesive layer further comprises an isocyanate compound and a polymerization initiator.

(14)

The dicing tape according to any one of the above (1) to (13), wherein a ratio of a thickness of the pressure-sensitive adhesive layer to a total thickness of the dicing tape is 1% or more and 15% or less.

(15)

A dicing die-bonding film comprising the dicing tape according to any one of (1) to (14) above and a die-bonding layer laminated on the adhesive layer of the dicing tape.

The dicing tape and the dicing die-bonding film according to the present embodiment are exemplified as described above, but the present invention is not limited to the dicing tape and the dicing die-bonding film exemplified above.

That is, various methods generally used for dicing tapes and dicing die-bonding films can be employed within a range not impairing the effects of the present invention.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

The dicing tape was manufactured as follows. In addition, a dicing die-bonding film is manufactured using the dicing tape.

< substrate layer >

In the examples, the structure was 3 layers (X layer/Y layer/X layer), and in the comparative examples, the structure was a single layer (Y layer).

[ non-elastomeric layer: x layer ]

The product name is as follows: WXK1233, WMX03

Metallocene polypropylene random copolymer

WINTEC series made by Japan Polypropylene core

[ elastomer layer: y layer)

The product name is as follows: EV250 and EV550

Ethylene-vinyl acetate copolymer resin

EVAFLEX series manufactured by DOW-MITSUI POLYCHEMICALS

The product name is as follows: vistamaxx

Propylene elastomer resin

Vistamaxx series manufactured by Exxon Mobil Japan K.K

Molding conditions

A substrate layer having a 3-layer structure of X layer/Y layer/X layer was produced using an extrusion T-die forming machine. Specifically, the laminate is formed by coextrusion from a T die and integrated, and after the extruded laminate is sufficiently cured, the laminate is wound into a roll shape to obtain a roll body. The extrusion temperature conditions were as follows.

Layer X (outer layer): 190 deg.C

Y layer (inner layer): 190 deg.C

Die temperature: 190 deg.C

The thicknesses of the base material layers in the examples and comparative examples are shown in table 1.

< adhesive layer >

(Synthesis of acrylic Polymer)

The following raw materials were charged into a reaction vessel equipped with a condenser tube, a nitrogen inlet tube, a thermometer and a stirring device, and polymerization treatment was carried out at 60 ℃ for 10 hours in a nitrogen gas flow, thereby synthesizing an acrylic polymer intermediate.

2-ethylhexyl acrylate (hereinafter also referred to as "2 EHA"): 100 parts by mass,

2-hydroxyethyl acrylate (hereinafter also referred to as "HEA"): 19 parts by mass,

Benzoyl peroxide: 0.4 part by mass,

Toluene: 80 parts by mass

To the synthesized acrylic polymer intermediate, 1.2 parts by mass of 2-methacryloyloxyethyl isocyanate (hereinafter also referred to as "MOI") was added, and an addition reaction treatment was performed at 50 ℃ for 60 hours in an air stream, thereby synthesizing an acrylic polymer.

(preparation of adhesive layer)

Thereafter, a binder solution was prepared according to the following composition.

Synthetic acrylic polymer: 100 parts by mass,

Polyisocyanate Compound

(product name "Coronate L", manufactured by Nippon polyurethane Co., Ltd.): 1.3 parts by mass,

Photopolymerization initiator

(product name "Irgacure 184", manufactured by Ciba Specialty Chemicals Co., Ltd.): : 3 parts by mass

A PET-based film was prepared as a release sheet. The adhesive solution prepared as above was coated on the side of the release sheet. The release sheet (PET film) was subjected to silicone treatment as release treatment on one surface thereof, and the release treated surface was coated with a pressure-sensitive adhesive solution. After the coating, the coating was heated at 120 ℃ for 2 minutes to dry the coating, thereby forming a pressure-sensitive adhesive layer having a thickness of 10 μm on a release sheet.

< making of dicing tape >

The exposed surface of the pressure-sensitive adhesive layer produced on the release sheet was bonded to each base material layer, and the resultant was stored at 23 ℃ for 72 hours to produce a dicing tape.

< production of chip bonding layer >

The following (a) to (e) were dissolved in methyl ethyl ketone to prepare a resin composition having a solid content concentration of 20 mass%.

(a) Acrylic resin (tradename "SG-P3", tradename chemical, glass transition temperature 12 ℃): 100 parts by mass

(b) Epoxy resin (product name "JER 1001", manufactured by Mitsubishi chemical corporation): 46 parts by mass

(c) 51 parts by mass of a phenol resin (product name "MEH-7851 ss" manufactured by MILDING CHEMICAL CO., LTD.) was prepared

(d) Spherical silica (product name "SO-25R" manufactured by Admatechs Co., Ltd.): 191 parts by mass

(e) Curing catalyst (product name "CUREZOL 2 PHZ" manufactured by four national chemical industry Co., Ltd.): 0.6 part by mass

The resin composition was applied to a release-treated film (release sheet) of polyethylene terephthalate film having a thickness of 50 μm, which had been subjected to silicone release treatment. Thereafter, the drying treatment was carried out at 130 ℃ for 2 minutes. Thus, a chip bonding layer having a thickness (average thickness) of 10 μm was produced.

< making of dicing die-bonding film >

The PET release sheet was peeled from the prepared dicing tape, and the chip bonding layer was bonded to the exposed adhesive layer. A hand roller was used for the lamination. Then, the cut tape side was irradiated with light at 300mJ/cm²Ultraviolet rays (cumulative light amount). Thereby manufacturing a dicing die-bonding film.

(examples 1 to 6)

Substrate layers having the configurations shown in table 1 were produced, and dicing tapes and dicing die-bonding films were produced by the methods described above.

Comparative examples 1 to 4

Substrate layers having the configurations shown in table 1 were prepared, and dicing tapes and dicing die-bonding films were produced in the same manner as in the examples.

Table 1 shows the configurations of the dicing tapes and the base material layers of the dicing die-bonding films used for producing the examples and comparative examples.

The physical properties (such as the permanent deformation ratio) of each dicing tape measured by the following method are shown in table 1.

[ Table 1]

< determination of permanent deformation ratio of dicing tape >

The dicing tapes thus produced were each cut into a width of 10mm to prepare samples. Next, the permanent deformation ratio of this sample was measured as follows. Specifically, the test was carried out using a tensile tester (product name "Tensilon", manufactured by Shimadzu corporation) under conditions of an initial inter-chuck distance of 50mm and a tensile speed of 100 mm/min. In the present measurement, stretching was performed in the MD direction, but the present invention is not limited thereto. Thereafter, the sheet was held for 1 minute while being stretched at room temperature (23 ℃) for 100% (to 2 times the length before stretching) or at-5 ℃ for 120%. Thereafter, the tensile force was gradually relaxed at a rate of 100 mm/min, the distance L between chucks at which the tensile force reached 0 was measured, and the percentage of the ratio of L to the initial distance between chucks was taken as the permanent deformation ratio. Fig. 7 shows a conceptual diagram of measurement for determining the permanent deformation ratio.

< determination of elastic modulus (tensile storage modulus) of dicing tape >

The respective dicing tapes manufactured as above were overlapped until the thickness reached 200 μm. Thereafter, the resultant was cut into a strip having a length of 40mm (measured length) and a width of 10mm by a cutter. Next, the tensile storage modulus at-50 to 100 ℃ was measured by a solid viscoelasticity measuring apparatus (product name "RSAIII", manufactured by Rheometric Scientific Co., Ltd.). The measurement conditions were set to a frequency of 1Hz, a temperature rise rate of 10 ℃/min, and a distance between chucks of 22.5 mm. The values at 23 ℃ and 60 ℃ were read, and the read values were used as the measured values of the tensile storage modulus. The elastic modulus was measured by 1-time measurement.

< evaluation of Using Properties of dicing die-bonded film >

In the actual production of semiconductor integrated circuits, a wafer is often cut in a state where circuits are already formed on the wafer (in a state where circuit layers are formed). When a circuit layer having a large space is formed, internal stress is likely to occur, and the entire wafer is likely to warp to some extent. In order to evaluate the usability under such a situation, a warpage adjusting layer (solidified layer) capable of causing warpage is provided on the wafer. The evaluation of the usability was carried out as follows, on the basis of the warpage of the wafer easily caused by providing the warpage adjusting layer on one surface side of the wafer.

(composition of warpage-adjusting layer)

The following (a) to (f) were dissolved in methyl ethyl ketone to prepare a composition for a warpage-adjusting layer having a solid content of 20 mass%.

(a) Acrylic resin (tradename "SG-70L", tradename of tradename chemical industries, Ltd.): 5 parts by mass

(b) Epoxy resin (trade name "JER 828" manufactured by Mitsubishi chemical corporation): 5 parts by mass

(c) 14 parts by mass of a phenol resin (trade name: LDR 8210: manufactured by KANTIANHUAI Co., Ltd.)

(d) Epoxy resin (trade name "MEH-8005" manufactured by Mitsubishi chemical corporation): 2 parts by mass

(e) Spherical silica (trade name "SO-25R" manufactured by Admatechs): 53 parts by mass

(f) Phosphorus-based catalyst (TPP-K): 1 part by mass

The above composition was applied to a release-treated film (release liner) of 50 μm thick polyethylene terephthalate film subjected to silicone release treatment, and then dried at 130 ℃ for 2 minutes. Thus, a warpage-regulating layer having a thickness (average thickness) of 25 μm was produced.

(preparation of evaluation wafer)

The warpage-adjusting layer thus produced was bonded to a wafer (bare wafer having no circuit layer), and the release film was removed. The conditions for bonding were 60 ℃, 0.1MPa, and 10 mm/s. Thereafter, the warpage-adjusting layer was heated in an oven at 175 ℃ for 1 hour to thermally cure the warpage-adjusting layer.

Next, a tape for wafer processing is bonded to the exposed surface of the wafer and fixed to the dicing ring, and a groove is formed in the surface on the warp adjusting layer side (half-cut processing). Specifically, grooves having a depth of 100 μm were formed in a lattice shape having a width of 20 μm and a width of 4mm × 11mm by using a dicing apparatus (DFD6361, DISCO Co.). Further, a back-grinding tape is bonded to the surface of the warpage-adjusting layer, and the wafer-processing tape is peeled off. Then, the back surface was polished by a back grinder DGP8760 manufactured by DISCO until the total thickness of the laminated body of the warpage-adjusting layer and the wafer became 55 μm.

Then, the exposed surface of the wafer is attached to the chip bonding layer. Specifically, the surface of the wafer exposed after polishing is attached to a chip bonding layer laminated on an adhesive layer of a dicing tape fixed to a dicing ring, and the back surface polishing tape is peeled off.

(expanding method)

The semiconductor wafer was cut and the dicing tape was heat-shrunk by using a die separation apparatus (DDS2300, manufactured by DISCO).

Specifically, the semiconductor wafer and the die bonding layer were first cut by a cold-expanding unit under conditions of an expansion temperature of-15 ℃, an expansion rate of 200 mm/sec, and an expansion amount of 12 mm.

Then, the dicing tape was heat-shrunk (heat-shrunk) by a heat-expanding means under conditions of an expansion amount of 10mm, a heating temperature of 250 ℃, an air volume of 40L/min, a heating distance of 20mm, and a rotation speed of 3 °/second.

(evaluation of incision)

The incision was measured using a digital microscope (VHX-6000, manufactured by Kenyx). For the measurement, after the thermal expansion was completed, the chip-to-chip spacing (notch) at the cut portion was observed with a digital microscope and the spacing length was measured. The cuts in the MD and TD directions were measured at 5 positions distributed arbitrarily selected, and the minimum value of the measured values was used. If the cut was 30 or more, the evaluation was "good", and if the cut was less than 30, the evaluation was "x". Note that, the arbitrary 5 positions are: located at 4 positions on the outermost peripheral portion of the circular wafer and spaced from each other by about 90 degrees in the circumferential direction and near the center of the wafer.

As is clear from the above evaluation results, the dicing die-bonding films of examples can maintain the cuts well after the expansion as compared with the dicing die-bonding films of comparative examples.

The cut tapes of the examples had a permanent set of 35% or more when they were stretched at 23 ℃ for 100% or at-5 ℃ for 120%.

The permanent set ratio is an index of whether or not the dicing tape is easily plastically deformed at that temperature. A set of 35% or more means that shrinkage due to elasticity after stretching can be relatively suppressed. Therefore, it is considered that the incision is not so much contracted after the stretching and can be sufficiently maintained after the expansion.

In the dicing tape of the example, for example, the ratio (B/a) of the elastic modulus (B) at 60 ℃ to the elastic modulus (a) at 23 ℃ is 0.17 or more.

The above ratio (B/a) is 0.17 or more: the elasticity at 60 ℃ at a higher temperature was not much reduced compared to the elasticity at 23 ℃. Therefore, it can be said that even if the cut tape is heated to 60 ℃ (for example, only the heat shrinkage of the edge portion is heated), the elasticity of the edge portion does not decrease much. The elasticity of the edge portions is not so reduced, and accordingly, the stretched dicing tape can be prevented from returning to its original shape by the elasticity of the edge portions. It is considered that the dicing tape on which the cleaved wafer is mounted can sufficiently maintain the notch after the dicing tape is expanded.

Industrial applicability

The dicing tape and the dicing die-bonding film of the present invention can be suitably used as an auxiliary tool in manufacturing a semiconductor integrated circuit, for example.

Claims

1. A dicing tape comprising: a base material layer and an adhesive layer superposed on the base material layer,

the cut tape has a permanent set ratio of 35% or more when stretched at 23 ℃.

2. A dicing tape comprising a base material layer and an adhesive layer superposed on the base material layer,

the cutting tape has a permanent set ratio of 35% or more when stretched at-5 ℃.

3. Dicing tape according to claim 1 or 2, wherein with respect to the modulus of elasticity determined with a dynamic visco-elastic tensile test,

the ratio of the elastic modulus B at 60 ℃ to the elastic modulus A at 23 ℃, namely B/A, is 0.17 or more.

4. Dicing tape according to claim 1 or 2, wherein with respect to the modulus of elasticity determined with a dynamic visco-elastic tensile test,

an elastic modulus A at 23 ℃ of 40 to 300MPa,

an elastic modulus B at 60 ℃ of 8MPa or more and 100MPa or less.

5. Dicing tape according to claim 1 or 2, wherein with respect to the modulus of elasticity determined with a dynamic visco-elastic tensile test,

the elastic modulus C at 100 ℃ is 0.5MPa or more and 20MPa or less.

6. A dicing die-bonding film comprising: the dicing tape according to any one of claims 1 to 5, and a chip bonding layer laminated on the adhesive layer of the dicing tape.