Dicing tape and dicing die-bonding film

Abstract

A dicing tape and a dicing die-bonding film are provided. The dicing tape comprises a base layer and an adhesive layer superimposed on the base layer, wherein the dicing tape has a permanent deformation rate of 35% or more when stretched at 23°C or -5°C.

Description

Technical Field

[0001] The present invention relates to a dicing tape used, for example, when manufacturing a semiconductor integrated circuit, and a dicing die-bonding film including the dicing tape. Background Art

[0002] Conventionally, dicing die-bonding films used in the manufacture of semiconductor integrated circuits are known. Such dicing die-bonding films, for example, comprise a dicing tape and a die-bonding layer laminated on the dicing tape and bonded to a wafer. The dicing tape comprises a base layer and an adhesive layer in contact with the die-bonding layer. Such dicing die-bonding films are used in the manufacture of semiconductor integrated circuits, for example, as described below.

[0003] The method of manufacturing a semiconductor integrated circuit generally includes a front-end process of forming a circuit surface on one side of a wafer using a highly integrated electronic circuit, and a back-end process of cutting chips from the wafer with the circuit surface formed thereon and assembling them.

[0004] Post-processes include, for example, the following: a mounting step in which the surface of the wafer opposite to the circuit surface is attached to the die bond layer and the wafer is fixed to the dicing tape; a dicing step in which the wafer attached to the dicing tape via the die bond layer is cut into small chips (dies) and divided into pieces; an expansion step in which the intervals between the small chips are increased; a pick-up step in which the die bond layer and the adhesive layer are peeled off to remove the die (dies) with the die bond layer attached; and a die bonding step in which the die (dies) with the die bond layer attached are adhered to the adherend. Semiconductor integrated circuits are manufactured through these steps.

[0005] In the aforementioned manufacturing method, the expansion step involves, for example, stretching the dicing tape radially at a low temperature (subfreezing point) with the wafer placed on the die bonding layer of the dicing tape, and then further stretching it at room temperature to increase the distance (kerf) between adjacent dies. Subsequently, to maintain the distance (kerf), a portion of the dicing tape, whose tension has been reduced by the stretching, is heat-shrunk. Specifically, the dicing tape is heat-shrunk in a portion located outside the portion overlapping the severed dies, thereby maintaining the distance (kerf).

[0006] However, during the expansion process, the temporarily stretched dicing tape may shrink due to its elasticity, and the aforementioned gap (notch) may no longer be maintained. If the gap (notch) cannot be maintained, the die will float, which will hinder the subsequent pickup process. To prevent this problem, it is highly desirable to have a dicing tape that can maintain a good notch after expansion.

[0007] In this regard, as a previous cutting tape, there is known a cutting tape that has a tensile load of 16 to 34 N at an elongation of 10% under test conditions of a width of 25 mm, a gauge length and a distance between clamping parts of 100 mm, and a tensile speed of 300 mm / min (Patent Document 1).

[0008] The dicing tape described in Patent Document 1 has adhesive strength that prevents wafer peeling during the expansion process and has the performance of being able to cut into dies. In addition, the die bonding layer can be relatively easily peeled off during the pickup process.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-155270 Summary of the Invention

[0012] Problems to be solved by the invention

[0013] However, it cannot be said that sufficient research has been conducted on dicing die-bonding films and dicing tapes that can maintain good cuts after expansion.

[0014] Therefore, an object of the present invention is to provide a dicing tape and a dicing die-bonding film capable of maintaining a good cut after expansion.

[0015] Solutions for solving problems

[0016] To solve the above problems, the dicing tape of the present invention comprises a base layer and an adhesive layer superposed on the base layer, wherein the dicing tape has a permanent deformation rate of 35% or more when stretched at 23°C.

[0017] According to the dicing tape having the above-mentioned structure, the incision can be maintained in good condition after expansion.

[0018] To solve the above problems, the dicing tape of the present invention comprises a base layer and an adhesive layer superposed on the base layer, wherein the dicing tape has a permanent deformation rate of 35% or more when stretched at -5°C.

[0019] According to the dicing tape having the above-mentioned structure, the incision can be maintained in good condition after expansion.

[0020] The dicing tape of the present invention preferably has a ratio (B / A) of the elastic modulus (B) at 60°C to the elastic modulus (A) at 23°C of 0.17 or greater, as measured by a dynamic viscoelastic tensile test. This allows the dicing tape to maintain its incision better after expansion at room temperature and subsequent heat shrinkage.

[0021] The dicing tape of the present invention preferably has an elastic modulus (A) of 40 MPa to 300 MPa at 23°C and an elastic modulus (B) of 8 MPa to 100 MPa at 60°C, as measured by a dynamic viscoelastic tensile test. This allows the dicing tape to maintain its shape better after expansion at room temperature and subsequent heat shrinkage.

[0022] The dicing tape of the present invention preferably has an elastic modulus (C) of 0.5 MPa to 20 MPa at 100°C as measured by a dynamic viscoelastic tensile test. This allows the incision to be better maintained after expansion at room temperature and subsequent heat shrinkage.

[0023] The dicing die-bonding film of the present invention includes the above-mentioned dicing tape and a die-bonding layer laminated on the adhesive layer of the dicing tape.

[0024] Effects of the Invention

[0025] The dicing tape and dicing die-bonding film of the present invention exhibit an effect of maintaining the cut edge in a good condition after expansion. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 : A cross-sectional view of the dicing die-bonding film of the present embodiment cut along the thickness direction.

[0027] Figure 2A : A cross-sectional view schematically showing a half-cut process in a method for manufacturing a semiconductor integrated circuit.

[0028] Figure 2B : A cross-sectional view schematically showing a half-cut process in a method for manufacturing a semiconductor integrated circuit.

[0029] Figure 2C : A cross-sectional view schematically showing a half-cut process in a method for manufacturing a semiconductor integrated circuit.

[0030] Figure 2D : A cross-sectional view schematically showing a half-cut process in a method for manufacturing a semiconductor integrated circuit.

[0031] Figure 3A : A cross-sectional view schematically showing a mounting step in a method for manufacturing a semiconductor integrated circuit.

[0032] Figure 3B : A cross-sectional view schematically showing a mounting step in a method for manufacturing a semiconductor integrated circuit.

[0033] Figure 4A: A cross-sectional view schematically showing a low-temperature expansion step in a method for manufacturing a semiconductor integrated circuit.

[0034] Figure 4B : A cross-sectional view schematically showing a low-temperature expansion step in a method for manufacturing a semiconductor integrated circuit.

[0035] Figure 4C : A cross-sectional view schematically showing a low-temperature expansion step in a method for manufacturing a semiconductor integrated circuit.

[0036] Figure 5A : A cross-sectional view schematically showing an expansion step at room temperature in a method for manufacturing a semiconductor integrated circuit.

[0037] Figure 5B : A cross-sectional view schematically showing an expansion step at room temperature in a method for manufacturing a semiconductor integrated circuit.

[0038] Figure 6 : A cross-sectional view schematically showing a pickup step in a method for manufacturing a semiconductor integrated circuit.

[0039] Figure 7 : Schematic diagram showing the concept of measuring permanent deformation rate.

[0040] Description of Reference Numerals

[0041] 1: Cutting die bonding film,

[0042] 10: Chip bonding layer,

[0043] 20: cutting belt,

[0044] 21: base material layer,

[0045] 22: Adhesive layer. DETAILED DESCRIPTION

[0046] Hereinafter, one embodiment of the dicing die-bonding film and the dicing tape of the present invention will be described with reference to the drawings.

[0047] The dicing die-bonding film 1 of the present embodiment includes a dicing tape 20 and a die-bonding layer 10 laminated on the dicing tape 20 and bonded to a semiconductor wafer.

[0048] The dicing tape 20 of this embodiment is generally a long sheet and is stored in a rolled state until use. The dicing die-bonding film 1 of this embodiment is used by being adhered to an annular frame having an inner diameter slightly larger than that of a silicon wafer to be cut.

[0049] The dicing tape 20 of the present embodiment includes a base material layer 21 and an adhesive layer 22 superposed on the base material layer 21 .

[0050] The dicing tape 20 of the present embodiment has a permanent deformation rate of 35% or more when stretched at 23° C. Usually, the permanent deformation rate when stretched at 23° C. is 100% or less.

[0051] The dicing tape 20 of the present embodiment has a permanent deformation rate of 35% or more when stretched at -5°C. Usually, the permanent deformation rate when stretched at -5°C is 100% or less.

[0052] The dicing tape 20 of the present embodiment has any of the above-mentioned structures, and thus can maintain the cut well after expansion.

[0053] The above-mentioned permanent set rate is a property when the dicing tape 20 is stretched 100% at 23°C, or when the dicing tape 20 is stretched 120% at -5°C. It can be measured at various temperatures according to the methods described in the Examples. For example, "stretched 100%" means stretching to twice the length before stretching.

[0054] The direction of stretching the slit tape 20 may be either the MD or TD direction, and the permanent deformation rate obtained by stretching in any direction may be equivalent to the above value. The average value of the measured values ​​obtained by three measurements is used as the above permanent deformation rate.

[0055] The above-mentioned permanent deformation rate can be increased, for example, by increasing the mass ratio of the easily plastically deformable resin in the base layer 21. On the other hand, the above-mentioned permanent deformation rate can be reduced, for example, by increasing the mass ratio of the elastomer resin in the base layer 21.

[0056] When the base material layer 21 is composed of multiple resin layers, the above-mentioned permanent deformation rate can be adjusted by changing the relative thickness of at least one layer. For example, the above-mentioned permanent deformation rate can be increased by relatively increasing the thickness of the resin layer that is more easily plastically deformed.

[0057] The dicing tape 20 preferably has an elastic modulus (A) of 40 MPa to 300 MPa at 23°C and an elastic modulus (B) of 8 MPa to 100 MPa at 60°C, as measured by a dynamic viscoelastic tensile test. This allows the slit to be maintained more effectively after expansion at room temperature and subsequent heat shrinkage.

[0058] The elastic modulus (A) at 23°C is more preferably 50 MPa or more and more preferably 250 MPa or less.

[0059] The elastic modulus (B) at 60°C is more preferably 10 MPa or more and more preferably 80 MPa or less.

[0060] In the cutting tape 20, regarding the elastic modulus measured by the dynamic viscoelastic tensile test, the elastic modulus (C) at 100°C is preferably not less than 0.5 MPa and not more than 20 MPa. By setting the elastic modulus (C) at 100°C to not less than 0.5 MPa, it is possible to more fully suppress the cutting tape 20 from melting, breaking, or deforming due to heat shrinkage. As a result, a more uniform incision can be achieved. In addition, by setting the elastic modulus (C) at 100°C to not more than 20 MPa, the cutting tape 20 can be more fully thermally shrunk by heat shrinkage. For this reason, by setting the elastic modulus (C) at 100°C to the above value, the incision can be maintained better after expansion at room temperature and then heat shrinkage.

[0061] The elastic modulus (C) at 100°C is more preferably 1 MPa or more, and more preferably 10 MPa or less.

[0062] The elastic modulus of the dicing tape 20 can be measured at various temperatures according to the method described in Examples. The elastic modulus is the value of the tensile storage modulus measured by dynamic viscoelasticity measurement.

[0063] The elastic moduli (A, B, C) can be increased, for example, by increasing the mass ratio of a resin having a relatively high elastic modulus in the base material layer 21. On the other hand, the elastic moduli can be decreased, for example, by decreasing the mass ratio of a resin having a relatively high elastic modulus.

[0064] When the base layer 21 is composed of multiple resin layers, the elastic modulus can be adjusted by changing the relative thickness of at least one layer. For example, the elastic modulus can be increased by relatively increasing the thickness of a resin layer with a relatively high elastic modulus.

[0065] In the dicing tape, the ratio (B / A) of the elastic modulus (B) at 60°C to the elastic modulus (A) at 23°C is preferably 0.17 or greater. This allows the incision to be better maintained after expansion at room temperature and subsequent heat shrinkage.

[0066] The above ratio (B / A) is more preferably 0.18 or more, and further preferably 0.20 or more.

[0067] It should be noted that the above ratio (B / A) may be 0.5 or less, or 0.3 or less.

[0068] The base layer 21 may have a single-layer structure or a laminated structure. The base layer 21 preferably has a laminated structure because the elastic modulus and permanent set rate of the base layer 21 can be easily adjusted by changing the type of resin contained in each layer or the thickness ratio of the layers.

[0069] Each layer of the base material layer 21 is, for example, a metal foil, a fiber sheet such as paper or cloth, a rubber sheet, a resin film, or the like.

[0070] Examples of the fiber sheet constituting the base material layer 21 include paper, woven fabric, and nonwoven fabric.

[0071] Examples of materials for 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 and alternating) copolymers; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); polyacrylates; polyvinyl chloride (PVC); polyurethanes; polycarbonates; polyphenylene sulfide (PPS); polyamides such as aliphatic polyamides and wholly aromatic polyamides (aramid); polyetheretherketone (PEEK); polyimides; polyetherimides; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymer); cellulose or cellulose derivatives; silicone-containing polymers; and fluorine-containing polymers. These can be used alone or in combination of two or more.

[0072] When the base material layer 21 includes a resin film, the resin film may be subjected to a stretching treatment or the like to control deformability such as elongation.

[0073] The surface of the base material layer 21 may be subjected to a surface treatment to improve adhesion with the adhesive layer 22. Examples of surface treatments include chemical or physical oxidation treatments such as chromic acid treatment, ozone exposure, flame exposure, high voltage electric shock exposure, and ionizing radiation treatment. Furthermore, a coating treatment using a coating agent such as an anchor coating agent, primer, or adhesive may also be applied.

[0074] The base material layer 21 is preferably composed of a plurality of layers, more preferably composed of at least three layers, and even more preferably composed of three layers.

[0075] When the base material layer 21 has a multi-layered structure (for example, a three-layer structure), there is an advantage in that the elastic modulus and permanent set rate can be adjusted relatively easily by changing the ratio of the thickness of each layer.

[0076] The three-layered base material layer 21 preferably includes two non-elastic layers (X, X) formed of a non-elastic body and an elastic layer (Y) formed of an elastomer and disposed between the two non-elastic layers (X layer / Y layer / X layer).

[0077] The elastomer layer is typically formed from a polymer material exhibiting rubber elasticity at room temperature (23°C). The elastomer layer is a layer having a permanent deformation rate of less than 35% when measured at 23°C in the same manner as described above. On the other hand, the non-elastic layer is a layer other than an elastomer.

[0078] Each layer of the elastomer having a three-layer laminated structure is generally formed of a resin. The elastomer having a three-layer laminated structure is produced, for example, by co-extrusion molding to integrate the three layers.

[0079] The non-elastic layer disposed outside has a melting point of, for example, 100° C. to 130° C. The non-elastic layer preferably has a molecular weight distribution dispersity (mass average molecular weight / number average molecular weight) of 3 or less when the constituent resin is measured by GPC.

[0080] The non-elastomer layer (X) may comprise low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene, and the like. Examples of polypropylene include homopolymers (homopolypropylene) and copolymers such as random polypropylene and block polypropylene. The polypropylene may be metallocene polypropylene synthesized using a metallocene catalyst. The non-elastomer layer (X) preferably comprises metallocene polypropylene.

[0081] On the other hand, the elastomer layer (Y) preferably contains ethylene-vinyl acetate copolymer (EVA) or an α-olefin-based thermoplastic elastomer. Examples of the α-olefin-based thermoplastic elastomer include homopolymers of α-olefins and copolymers of two or more α-olefins.

[0082] The thickness of the substrate layer 21 can be 60 μm to 160 μm. The thickness of the substrate layer 21 is preferably 60 μm to 120 μm, and more preferably 80 μm to 100 μm. The thickness is the average of the values ​​measured at five randomly selected locations using a direct-reading thickness gauge.

[0083] The ratio of the thickness of one layer (X layer) in the non-elastomer layer to the thickness of the elastomer layer (Y layer) (X layer / Y layer) is preferably in the range of 0.05 to 0.25.

[0084] The back side of the base material layer 21 (the side not overlapped with the adhesive layer 22 ) may be subjected to a release treatment using a release agent (release agent) such as a silicone resin or a fluorine resin to impart releasability.

[0085] From the perspective of being able to supply active energy rays such as ultraviolet rays to the pressure-sensitive adhesive layer 22 from the back side, the base material layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like.

[0086] The dicing tape 20 of this embodiment may also include a release sheet that covers one surface of the adhesive layer 22 (the surface of the adhesive layer 22 that does not overlap the base material layer 21) before use. When the die bond layer 10, which has a smaller area than the adhesive layer 22, is positioned so as to be accommodated within the adhesive layer 22, the release sheet is positioned so as to cover both the adhesive layer 22 and the die bond layer 10. The release sheet is used to protect the adhesive layer 22 and is removed before the die bond layer 10 is attached to the adhesive layer 22.

[0087] As the release sheet, for example, a plastic film or paper surface-treated with a release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide-based release agent can be used.

[0088] In addition, as a release sheet, films made of fluorine-based polymers such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, and chlorofluoroethylene-vinylidene fluoride copolymer; films made of polyolefins such as polyethylene and polypropylene; and films made of polyesters such as polyethylene terephthalate (PET) can be used.

[0089] 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.

[0090] It should be noted that the release sheet can be used as a supporting material for supporting the adhesive layer 22. The release sheet is particularly suitable for use when the adhesive layer 22 is superimposed on the base layer 21. Specifically, the adhesive layer 22 can be superimposed on the base layer 21 in a state where the release sheet and the adhesive layer 22 are stacked, and after superposition, the release sheet can be peeled off (transferred), thereby superimposing the adhesive layer 22 on the base layer 21.

[0091] In the present embodiment, the adhesive layer 22 contains, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator.

[0092] 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 usually the same as those of the base material layer 21 .

[0093] In the dicing tape 20 of the present embodiment, the ratio of the thickness of the adhesive layer 22 to the total thickness of the dicing tape 20 may be 1% or more and 15% or less.

[0094] The acrylic polymer described above contains 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 its molecule. These constituent units constitute the main chain of the acrylic polymer. The side chains in the acrylic polymer described above are contained in the constituent units that constitute the main chain.

[0095] In this specification, the term "(meth)acrylate" refers to at least one of methacrylate and acrylate. Similarly, the term "(meth)acrylic acid" refers to at least one of methacrylic acid and acrylic acid.

[0096] In the acrylic polymer contained in the adhesive layer 22, the above-mentioned constituent units can be 1 H-NMR, 13 The molar ratio of the above-mentioned structural units in the acrylic polymer can be generally calculated based on the amount (charge amount) of the acrylic polymer when it is polymerized.

[0097] The structural units of the aforementioned alkyl (meth)acrylates are derived from alkyl (meth)acrylate monomers. In other words, the molecular structure formed after the polymerization of the alkyl (meth)acrylate monomers is the structural unit of the alkyl (meth)acrylate. The term "alkyl" refers to the hydrocarbon portion that forms an ester bond with (meth)acrylic acid.

[0098] The hydrocarbon in the alkyl portion in the structural unit of the alkyl (meth)acrylate may be a saturated hydrocarbon or an unsaturated hydrocarbon.

[0099] It should be noted that the alkyl portion preferably does not contain polar groups containing oxygen (O), nitrogen (N), or the like. This can prevent the polarity of the alkyl polymer from increasing significantly. Consequently, excessive affinity of the adhesive layer 22 for the die bond layer 10 can be prevented. This allows for better peeling of the dicing tape 20 from the die bond layer 10. The number of carbon atoms in the alkyl portion can be from 6 to 10.

[0100] Examples of the constituent units of the alkyl (meth)acrylate include constituent units such as hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and decyl (meth)acrylate.

[0101] The acrylic polymer has a hydroxyl group-containing (meth)acrylate structural unit, and the hydroxyl group of the structural unit easily reacts with an isocyanate group.

[0102] By pre-incorporating an acrylic polymer having a hydroxyl (meth)acrylate-containing structural unit and an isocyanate compound into the adhesive layer 22, the adhesive layer 22 can be appropriately cured. This allows the acrylic polymer to be fully gelled, allowing the adhesive layer 22 to maintain its shape while exhibiting adhesive properties.

[0103] The constituent units of the hydroxyl group-containing (meth)acrylate are preferably constituent units of a hydroxyl group-containing C2-C4 alkyl (meth)acrylate. The term "C2-C4 alkyl" indicates the number of carbon atoms in the hydrocarbon portion that forms an ester bond with the (meth)acrylic acid. In other words, a hydroxyl group-containing C2-C4 alkyl (meth)acrylate monomer is a monomer formed by forming an ester bond between (meth)acrylic acid and an alcohol having 2 to 4 carbon atoms (typically a divalent alcohol).

[0104] The hydrocarbon portion of the C2-C4 alkyl group is typically a saturated hydrocarbon. For example, the hydrocarbon portion of the C2-C4 alkyl group is a linear saturated hydrocarbon or a branched saturated hydrocarbon. The hydrocarbon portion of the C2-C4 alkyl group preferably does not contain polar groups containing oxygen (O), nitrogen (N), or the like.

[0105] Examples of the constituent units of the hydroxyl-containing C2-C4 alkyl (meth)acrylate include constituent units of hydroxybutyl (meth)acrylate such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxyn-butyl (meth)acrylate, and hydroxyisobutyl (meth)acrylate. In the constituent units of hydroxybutyl (meth)acrylate, the hydroxyl group (—OH group) may be bonded to a terminal carbon (C) of the hydrocarbon portion or to a carbon (C) other than the terminal carbon of the hydrocarbon portion.

[0106] The acrylic polymer described above includes a structural unit of a polymerizable group-containing (meth)acrylate having a polymerizable unsaturated double bond in a side chain.

[0107] By making the acrylic polymer contain a constituent unit of a (meth)acrylate containing a polymerizable group, the adhesive layer 22 can be cured by irradiation with active energy rays (such as ultraviolet rays) before the pickup process. Specifically, by irradiation with active energy rays such as ultraviolet rays, free radicals are generated by the photopolymerization initiator, and through the action of these free radicals, the acrylic polymers can undergo a cross-linking reaction. As a result, the adhesive force of the adhesive layer 22 before irradiation can be reduced by irradiation. In addition, the chip bonding layer 10 can be well peeled from the adhesive layer 22.

[0108] Incidentally, as active energy rays, ultraviolet rays, radiation rays, and electron beams can be used.

[0109] Specifically, the polymerizable group-containing (meth)acrylate constituent unit may have a molecular structure in which an isocyanate group of an isocyanate group-containing (meth)acrylate monomer and a hydroxyl group in the hydroxyl group-containing (meth)acrylate constituent unit form a urethane bond.

[0110] The polymerizable group-containing (meth)acrylate constituent units having a polymerizable group can be prepared after polymerization of an acrylic polymer. For example, after copolymerization of an alkyl (meth)acrylate monomer and a hydroxyl group-containing (meth)acrylate monomer, a portion of the hydroxyl groups in the hydroxyl group-containing (meth)acrylate constituent units can be subjected to a urethanization reaction with the isocyanate groups of an isocyanate group-containing polymerizable monomer to obtain the polymerizable group-containing (meth)acrylate constituent units.

[0111] The isocyanate group-containing (meth)acrylate monomer preferably has one isocyanate group and one (meth)acryloyl group in the molecule. Examples of such monomers include 2-isocyanatoethyl (meth)acrylate.

[0112] The adhesive layer 22 of the dicing tape 20 in this embodiment further contains an isocyanate compound. A portion of the isocyanate compound may be in a state of reacting by a urethanization reaction or the like.

[0113] The isocyanate compound has multiple isocyanate groups in its molecule. By having multiple isocyanate groups in the isocyanate compound, a cross-linking reaction can be performed between the acrylic polymers in the adhesive layer 22. Specifically, one isocyanate group of the isocyanate compound reacts with a hydroxyl group of the acrylic polymer, and the other isocyanate groups react with hydroxyl groups of other acrylic polymers, thereby achieving a cross-linking reaction via the isocyanate compound.

[0114] Examples of the isocyanate compound include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, and aromatic aliphatic diisocyanates.

[0115] Furthermore, examples of the isocyanate compound include polymeric polyisocyanates such as dimers and trimers of diisocyanate, and polymethylene polyphenylene polyisocyanates.

[0116] Examples of the isocyanate compound include polyisocyanates obtained by reacting an excess of the above-mentioned isocyanate compounds with an active hydrogen-containing compound. Examples of the active hydrogen-containing compound include low-molecular-weight active hydrogen-containing compounds and high-molecular-weight active hydrogen-containing compounds.

[0117] In addition, as an isocyanate compound, allophanated polyisocyanate, biuret polyisocyanate, etc. can also be used.

[0118] The above-mentioned isocyanate compounds can be used alone or in combination of two or more.

[0119] The isocyanate compound is preferably a reaction product of an aromatic diisocyanate and a low-molecular-weight compound containing active hydrogen. The isocyanate group in the reaction product of the aromatic diisocyanate has a relatively slow reaction rate, so the adhesive layer 22 containing the reaction product can be prevented from overcuring. The isocyanate compound is preferably one having three or more isocyanate groups in the molecule.

[0120] The polymerization initiator contained in the adhesive layer 22 is a compound that can initiate a polymerization reaction by applying heat energy or light energy. By making the adhesive layer 22 contain a polymerization initiator, a cross-linking reaction can be caused between acrylic polymers when heat energy or light energy is applied to the adhesive layer 22. Specifically, a polymerization reaction between polymerizable groups can be initiated between acrylic polymers having constituent units of (meth)acrylate containing polymerizable groups, thereby curing the adhesive layer 22. As a result, the adhesive force of the adhesive layer 22 can be reduced, and the chip bonding layer 10 can be easily peeled off from the cured adhesive layer 22 during the pickup process.

[0121] As the polymerization initiator, for example, a photopolymerization initiator or a thermal polymerization initiator can be used. As the polymerization initiator, a general commercially available product can be used.

[0122] The adhesive layer 22 may further contain other components in addition to the above-mentioned components. Examples of such other components include tackifiers, plasticizers, fillers, antioxidants, antioxidants, UV absorbers, light stabilizers, heat stabilizers, antistatic agents, surfactants, and light release agents. The types and amounts of such other components may be appropriately selected depending on the intended purpose.

[0123] Next, the dicing die-bonding film 1 of this embodiment will be described in detail.

[0124] The dicing die-bonding film 1 of the present embodiment includes the above-mentioned dicing tape 20 and a 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 during the manufacture of a semiconductor integrated circuit.

[0125] The die bond layer 10 may include at least one of a thermosetting resin and a thermoplastic resin. The die bond layer 10 preferably includes a thermosetting resin and a thermoplastic resin.

[0126] Examples of thermosetting resins include epoxy resins, phenolic resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. A single thermosetting resin may be used, or two or more may be used. Epoxy resins are preferred as thermosetting resins because they contain fewer ionic impurities that can cause corrosion of the semiconductor chip being chip-bonded. Phenolic resins are preferred as curing agents for epoxy resins.

[0127] 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, trihydroxyphenylmethane type, tetrahydroxyphenylethane type, hydantoin type, triglycidyl isocyanurate type, and glycidylamine type epoxy resins.

[0128] Phenolic resins can function as curing agents for epoxy resins. Examples of phenolic resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrene such as poly(p-styrene oxide).

[0129] Examples of the novolac-type phenolic resin include phenol novolac resin, phenol aralkyl resin, cresol novolac resin, t-butylphenol novolac resin, and nonylphenol novolac resin.

[0130] As the phenol resin, only one type may be used or two or more types may be used.

[0131] In the die bond layer 10 , the hydroxyl group of the phenol resin is preferably 0.5 to 2.0 equivalents, more preferably 0.7 to 1.5 equivalents, per 1 equivalent of the epoxy group of the epoxy resin.

[0132] When the die bond layer 10 includes a thermosetting resin, the content of the thermosetting resin in the die bond 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, relative to the total mass of the die bond layer 10. Thus, the die bond layer 10 can appropriately function as a thermosetting adhesive.

[0133] As thermoplastic resins that can be included in the chip bonding layer 10, for example, there can be listed: natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylate copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, 6-nylon, 6,6-nylon (trade name) and other polyamide resins, phenoxy resins, acrylic resins, saturated polyester resins such as PET and PBT, polyamide-imide resins, fluororesins, etc.

[0134] As the thermoplastic resin, acrylic resin is preferred because it contains less ionic impurities and has high heat resistance, thereby further ensuring the adhesiveness of the die-bonding layer 10 .

[0135] As the above-mentioned thermoplastic resin, only one kind may be used or two or more kinds may be used.

[0136] The acrylic resin is preferably a polymer in which the constituent units of the (meth)acrylate are the largest by mass ratio among the constituent units in the molecule. Examples of the (meth)acrylate include C2 to C4 alkyl (meth)acrylates.

[0137] The acrylic resin may further include a structural unit derived from another monomer component copolymerizable with the alkyl (meth)acrylate monomer.

[0138] 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 various other polyfunctional monomers.

[0139] From the perspective of being able to exert higher cohesive force in the chip bonding layer 10, the above-mentioned acrylic resin is preferably a copolymer of (meth)acrylate alkyl ester (especially (meth)acrylate alkyl ester having an alkyl part with a carbon number of 4 or less) and a carboxyl group-containing monomer and a nitrogen atom-containing monomer and a polyfunctional monomer (especially a polyglycidyl polyfunctional monomer), and more preferably a copolymer of ethyl acrylate and butyl acrylate and acrylic acid and acrylonitrile and polyglycidyl (meth)acrylate.

[0140] From the perspective of easily setting the elasticity and viscosity of the die-bonding layer 10 within desired ranges, the glass transition temperature (Tg) of the acrylic resin is preferably 5° C. to 35° C., more preferably 10° C. to 30° C.

[0141] When the die bond layer 10 includes a thermosetting resin and a thermoplastic resin, the content of the thermoplastic resin in the die bond 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 even more preferably 45% by mass or more and 55% by mass or less, relative to the total mass of the organic components other than the filler (e.g., thermosetting resin, thermoplastic resin, curing catalyst, silane coupling agent, dye). It should be noted that the elasticity and viscosity of the die bond layer 10 can be adjusted by varying the content of the thermosetting resin.

[0142] When the thermoplastic resin of the die bond layer 10 has a thermosetting functional group, for example, a thermosetting functional group-containing acrylic resin can be used as the thermoplastic resin. The thermosetting functional group-containing acrylic resin preferably contains a structural unit derived from an alkyl (meth)acrylate in the molecule at the highest mass ratio. Examples of the alkyl (meth)acrylate include the (meth)alkyl (meth)acrylates exemplified above.

[0143] On the other hand, examples of the thermosetting functional group in the thermosetting functional group-containing acrylic resin include a glycidyl group, a carboxyl group, a hydroxyl group, and an isocyanate group.

[0144] The die bonding layer 10 preferably contains a thermosetting functional group-containing acrylic resin and a curing agent. Examples of the curing agent include those listed as curing agents that can be included 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 multiple phenolic structures is preferably used as the curing agent. For example, the various phenolic resins described above can be used as the curing agent.

[0145] The die bond layer 10 preferably contains a filler. By varying the amount of filler in the die bond layer 10, the elasticity and viscosity of the die bond layer 10 can be more easily adjusted. Furthermore, the physical properties of the die bond layer 10, such as electrical conductivity, thermal conductivity, and elastic modulus, can be adjusted.

[0146] Examples of the filler include inorganic fillers and organic fillers, and inorganic fillers are preferred.

[0147] Examples of inorganic fillers include fillers containing silicon dioxide such as aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, boron nitride, crystalline silicon dioxide, and amorphous silicon dioxide. Inorganic fillers may be made of simple metals such as aluminum, gold, silver, copper, and nickel, or alloys thereof. Examples of fillers include aluminum borate whiskers, amorphous carbon black, and graphite. The filler may be in various shapes, such as spherical, needle-like, or flaky. The filler may be composed of only one of the aforementioned fillers or two or more.

[0148] The average particle size of the filler is preferably greater than or equal to 0.005 μm and less than or equal to 10 μm, more preferably greater than or equal to 0.005 μm and less than or equal to 1 μm. By making the average particle size greater than or equal to 0.005 μm, the wettability and adhesion to adherends such as semiconductor wafers are further improved. By making the average particle size less than or equal to 10 μm, the characteristics brought about by the added filler can be more fully utilized, and the heat resistance of the chip bonding layer 10 can be further utilized. The average particle size of the filler can be obtained, for example, using a photometric particle size distribution meter (for example, product name "LA-910", manufactured by HORIBA, Ltd.).

[0149] When the die bond layer 10 contains a filler, the content ratio of the filler relative to the total mass of the die bond layer 10 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.

[0150] The die-bonding layer 10 may contain other components as necessary. Examples of such other components include a curing catalyst, a flame retardant, a silane coupling agent, an ion scavenger, and a dye.

[0151] Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resins.

[0152] Examples of the silane coupling agent include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane.

[0153] Examples of the ion scavenger include hydrotalcites, bismuth hydroxide, and benzotriazole.

[0154] As the other additives, only one type may be used or two or more types may be used.

[0155] From the viewpoint of easy adjustment of elasticity and viscosity, the die-bonding layer 10 preferably contains a thermoplastic resin (particularly an acrylic resin), a thermosetting resin, and a filler.

[0156] In the die bonding layer 10 , the content of thermoplastic resins such as acrylic resins relative to the total mass of organic components excluding fillers 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.

[0157] The content of the filler relative to the total mass of the die bond layer 10 is preferably 30 mass % to 70 mass %, more preferably 40 mass % to 60 mass %, and further preferably 42 mass % to 55 mass %.

[0158] The thickness of the die bonding layer 10 is not particularly limited, and is, for example, not less than 1 μm and not more than 200 μm. The upper limit of the thickness is preferably 100 μm, and more preferably 80 μm. The lower limit of the thickness is preferably 3 μm, and more preferably 5 μm. It should be noted that when the die bonding layer 10 is a laminate, the above thickness is the total thickness of the laminate.

[0159] The glass transition temperature (Tg) of the die bond layer 10 is preferably 0°C or higher, more preferably 10°C or higher. Setting the glass transition temperature at 0°C or higher allows the die bond layer 10 to be easily cut by cold expansion. The upper limit of the glass transition temperature of the die bond layer 10 is, for example, 100°C.

[0160] like Figure 1 As shown, the die bonding layer 10 may have a single-layer structure. In this specification, a single layer refers to a layer consisting of only one composition. A structure in which multiple layers consisting of the same composition are stacked is also considered a single layer.

[0161] On the other hand, the die-bonding layer 10 may have a multilayer structure in which layers formed of two or more different compositions are stacked, for example.

[0162] The dicing die-bonding film 1 of this embodiment cures the adhesive layer 22 during use, for example, by irradiating it with ultraviolet light. Specifically, after the die-bonding layer 10, with a semiconductor wafer bonded to one side, and the adhesive layer 22, attached to the other side of the die-bonding layer 10, are stacked, at least the adhesive layer 22 is irradiated with ultraviolet light. For example, ultraviolet light is irradiated from the side where the base layer 21 is disposed, and the ultraviolet light passes through the base layer 21 and reaches the adhesive layer 22. The adhesive layer 22 is cured by the irradiation with ultraviolet light.

[0163] Since the adhesive layer 22 is cured after irradiation, the adhesive strength of the adhesive layer 22 can be reduced. Therefore, the die bond layer 10 (in a state where the semiconductor wafer is bonded) can be relatively easily peeled from the adhesive layer 22 after irradiation.

[0164] The dicing die-bonding film 1 of this embodiment may include a release sheet before use that covers one surface of the die-bonding layer 10 (the surface of the die-bonding layer 10 not overlapping the adhesive layer 22). The release sheet is used to protect the die-bonding layer 10 and is removed immediately before attaching an adherend (e.g., a semiconductor wafer) to the die-bonding layer 10.

[0165] As the release sheet, the same release sheet as the above-mentioned release sheet can be used. The release sheet can be used as a supporting material for supporting the chip bonding layer 10. The release sheet is suitable for use when the chip bonding layer 10 is overlapped on the adhesive layer 22. In detail, the chip bonding layer 10 and the adhesive layer 22 can be overlapped in a state where the release sheet and the chip bonding layer 10 are stacked, and the release sheet can be peeled off (transferred) after overlapping, thereby overlapping the chip bonding layer 10 on the adhesive layer 22.

[0166] Since the dicing die-bonding film 1 of the present embodiment is configured as described above, the cut can be maintained well after expansion.

[0167] Next, a method for manufacturing the dicing tape 20 and the dicing die-bonding film 1 according to the present embodiment will be described.

[0168] The method for manufacturing the dicing die-bonding film 1 according to the present embodiment includes:

[0169] A step of manufacturing the dicing tape 20 (a method of manufacturing the dicing tape), and a step of laminating the die bond layer 10 on the manufactured dicing tape 20 to manufacture the dicing die bond film 1 .

[0170] A method for manufacturing a cutting tape (a process for manufacturing a cutting tape) comprises:

[0171] Synthesis process for synthesizing acrylic polymers;

[0172] an adhesive layer forming step of volatilizing a solvent from an adhesive composition comprising the acrylic polymer, the isocyanate compound, the polymerization initiator, the solvent, and other components appropriately added according to the purpose to form the adhesive layer 22; and

[0173] In the lamination step, the adhesive layer 22 and the base layer 21 are bonded together to laminate the base layer 21 and the adhesive layer 22 .

[0174] In the synthesis step, for example, a C9-C11 alkyl (meth)acrylate monomer and a hydroxyl group-containing (meth)acrylate monomer are radically polymerized to synthesize an acrylic polymer intermediate.

[0175] Free radical polymerization can be carried out by conventional methods. For example, the aforementioned monomers can be dissolved in a solvent, stirred while heating, and a polymerization initiator can be added to synthesize an acrylic polymer intermediate. To adjust the molecular weight of the acrylic polymer, polymerization can also be carried out in the presence of a chain transfer agent.

[0176] Next, a portion of the hydroxyl groups in the hydroxyl group-containing (meth)acrylate structural units contained in the acrylic polymer intermediate are bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer through a urethanization reaction. As a result, a portion of the hydroxyl group-containing (meth)acrylate structural units becomes polymerizable group-containing (meth)acrylate structural units.

[0177] The urethanization reaction can be carried out by conventional methods. For example, the acrylic polymer intermediate and the isocyanate group-containing polymerizable monomer are stirred while heating in the presence of a solvent and a urethanization catalyst. This allows the isocyanate groups of the isocyanate group-containing polymerizable monomer to form urethanic bonds with some of the hydroxyl groups of the acrylic polymer intermediate.

[0178] In the adhesive layer production process, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare an adhesive composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Next, the adhesive composition is applied to a release sheet. As a coating method, for example, a common coating method such as roller coating, screen coating, or gravure coating is adopted. The applied composition is subjected to a desolvation treatment, a curing treatment, etc., thereby curing the applied adhesive composition to produce the adhesive layer 22.

[0179] In the lamination step, the adhesive layer 22 overlapped with the release sheet is laminated on the base layer 21. The release sheet may be overlapped with the adhesive layer 22 until use.

[0180] To promote the reaction between the crosslinking agent and the acrylic polymer and to promote the reaction between the crosslinking agent and the surface of the base layer 21 , an aging treatment step may be performed at 50° C. for 48 hours after the lamination step.

[0181] It should be noted that the base material layer 21 can be made of commercially available films or by conventional film forming methods. Examples of film forming methods include calendering film forming, casting in an organic solvent, inflation extrusion in a closed system, T-die extrusion, and dry lamination. Alternatively, coextrusion molding can be used.

[0182] Through these steps, the dicing tape 20 can be manufactured.

[0183] The method for manufacturing a dicing die-bonding film (a process for manufacturing a dicing die-bonding film) includes the following steps:

[0184] a resin composition preparation step of preparing a resin composition for forming the die bonding layer 10;

[0185] a die bonding layer manufacturing step of manufacturing a die bonding layer 10 from a resin composition; and

[0186] In the attaching step, the die bond layer 10 is attached to the adhesive layer 22 of the dicing tape 20 produced as described above.

[0187] In the resin composition preparation process, for example, an epoxy resin, an epoxy resin curing catalyst, an acrylic resin, a phenolic resin, and a solvent are mixed and each resin is dissolved in the solvent to prepare the resin composition. The viscosity of the composition can be adjusted by varying the amount of solvent. It should be noted that commercially available products can be used as these resins.

[0188] In the die bond layer production process, for example, the resin composition prepared as described above is applied to a release sheet. The coating method is not particularly limited, and conventional coating methods such as roll coating, screen coating, and gravure coating can be employed. Subsequently, the applied composition is cured by desolvation treatment, curing treatment, and the like, as needed, to produce the die bond layer 10.

[0189] In the laminating process, the release sheet is peeled off from the adhesive layer 22 of the dicing tape 20 and the chip bonding layer 10, respectively, and the chip bonding layer 10 is directly contacted with the adhesive layer 12. For example, lamination can be performed by pressure bonding. The temperature during lamination is not particularly limited, for example, it is 30°C or higher and 50°C or lower, preferably 35°C or higher and 45°C or lower. The linear pressure during lamination is not particularly limited, preferably 0.1kgf / cm or higher and 20kgf / cm or lower, more preferably 1kgf / cm or higher and 10kgf / cm or lower.

[0190] 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 its use will be described below.

[0191] The method of manufacturing a semiconductor integrated circuit generally includes the steps of cutting chips from a semiconductor wafer having a circuit surface formed thereon and assembling the chips.

[0192] This process includes, for example, the following steps: a half-cutting step in which grooves are formed in the semiconductor wafer to process the semiconductor wafer into dies by cutting, and the semiconductor wafer is then ground to reduce its thickness; a mounting step in which one side of the half-cut semiconductor wafer (e.g., the side opposite the circuit surface) is attached to the die bond layer 10 and the semiconductor wafer is fixed to the dicing tape 20; an expansion step in which the interval between the half-cut semiconductor dies is increased; a pickup step in which the die bond layer 10 is peeled from the adhesive layer 22 and the semiconductor die is removed while the die bond layer 10 is attached; and a die bonding step in which the semiconductor die, still attached to the die bond layer 10, is bonded to an adherend. When performing these steps, the dicing tape (dicing die bonding film) of this embodiment is used as a manufacturing aid.

[0193] In the half-cutting process, Figures 2A to 2D As shown, a half-cutting process is performed to cut a semiconductor integrated circuit into small pieces (dies). Specifically, a wafer processing tape T is attached to the surface of the semiconductor wafer opposite to the circuit surface. In addition, a cutting ring R is attached to the wafer processing tape T. With the wafer processing tape T attached, a groove for cutting is formed. A back grinding tape G is attached to the surface with the groove formed, and the wafer processing tape T that was originally attached is peeled off. With the back grinding tape G attached, grinding is performed until the semiconductor wafer reaches a predetermined thickness.

[0194] During the installation process, Figure 3A-3B As shown, after attaching the dicing ring R to the adhesive layer 22 of the dicing tape 20, the semiconductor wafer that has been half-cut is attached to the exposed surface of the die-bonding layer 10. Thereafter, the back grinding tape G is peeled off from the semiconductor wafer.

[0195] In the expansion process, Figures 4A to 4C As shown, after the cutting ring R is installed on the adhesive layer 22 of the cutting tape 20, it is fixed to the holding tool H of the expansion device. The lifting member U of the expansion device is lifted from the lower side of the cutting chip bonding film 1, thereby stretching the cutting chip bonding film 1 and expanding it in the surface direction. In this way, the semiconductor wafer that has been half-cut is cut under specific temperature conditions. The above temperature conditions are, for example, -20 to 5°C, preferably -15 to 0°C, and more preferably -10 to -5°C. The lifting member U is lowered to release the expansion state (so far it is a cold expansion process).

[0196] Furthermore, in the expansion process, Figure 5A-5B As shown in FIG. 1 , the dicing tape 20 is stretched under a higher temperature condition to expand the area. This separates the adjacent semiconductor chips in the film surface direction, further increasing the distance between them (room temperature expansion process).

[0197] Here, in order to maintain the intervals between the cut (small) semiconductor wafers, a portion of the dicing tape 20 is thermally shrunk (heat shrunk). Specifically, the portion outside the portion overlapping the semiconductor wafer is thermally shrunk (heat shrunk) to fix the dicing tape 20.

[0198] During the picking process, Figure 6 As shown, the semiconductor chip with the die-bonding layer 10 attached is peeled 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 through the dicing tape 20. The lifted semiconductor chip is held by the suction jig J.

[0199] In the die bonding step, the semiconductor chip with the die bonding layer 10 attached thereto is bonded to an adherend.

[0200] The matters disclosed in this specification include the following matters. (1)

[0202] A dicing tape comprising a base layer and an adhesive layer superposed on the base layer, wherein the permanent deformation rate when stretched at 23° C. is 35% or more. (2)

[0204] A dicing tape comprising a base layer and an adhesive layer superposed on the base layer, wherein the permanent deformation rate when stretched at -5°C is 35% or more. (3)

[0206] The dicing tape according to (1) or (2), wherein, regarding the elastic modulus measured by a dynamic viscoelastic tensile test,

[0207] The ratio (B / A) of the elastic modulus (B) at 60°C to the elastic modulus (A) at 23°C is 0.17 or more and 0.50 or less. (4)

[0209] The dicing tape according to any one of (1) to (3) above, wherein the elastic modulus measured by a dynamic viscoelastic tensile test is

[0210] The elastic modulus (A) at 23°C is 40 MPa or more and 300 MPa or less,

[0211] The elastic modulus (B) at 60°C is 8 MPa or more and 100 MPa or less. (5)

[0213] The dicing tape according to any one of (1) to (4) above, wherein the elastic modulus measured by a dynamic viscoelastic tensile test is:

[0214] The elastic modulus (C) at 100°C is 0.5 MPa or more and 20 MPa or less. (6)

[0216] The dicing tape according to any one of (1) to (5) above, wherein the base layer is composed of a plurality of layers. (7)

[0218] The cutting tape according to any one of (1) to (6) above, wherein the base layer is composed of at least three layers and has two non-elastic layers formed of a non-elastic body, and an elastomer layer arranged between the two non-elastic layers and formed of an elastomer. (8)

[0220] The cutting tape according to any one of (1) to (7) above, wherein the non-elastic layer comprises polypropylene. (9)

[0222] The dicing tape according to any one of (1) to (8) above, wherein the elastomer layer includes at least one of ethylene-vinyl acetate copolymer (EVA) and α-olefin-based thermoplastic elastomer. (10)

[0224] The cutting tape according to any one of (7) to (9) above, wherein the ratio (X layer / Y layer) of the thickness of one layer (X layer) in the above non-elastic layer to the thickness of the above elastomer layer (Y layer) is in the range of greater than 0.05 and less than 0.25. (11)

[0226] The dicing tape according to any one of (1) to (10) above, wherein the base layer has a thickness of 60 μm or more and 160 μm or less. (12)

[0228] The cutting tape according to any one of (1) to (11) above, wherein the adhesive layer comprises an acrylic polymer having in its molecule at least: a constituent unit of an alkyl (meth)acrylate, a constituent unit of a hydroxyl (meth)acrylate, and a constituent unit of a (meth)acrylate containing a polymerizable group. (13)

[0230] The dicing tape according to the above (12), wherein the adhesive layer further contains an isocyanate compound and a polymerization initiator. (14)

[0232] The dicing tape according to any one of (1) to (13) above, wherein a ratio of the thickness of the adhesive layer to the total thickness of the dicing tape is 1% or more and 15% or less. (15)

[0234] 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.

[0235] The dicing tape and the dicing die-bonding film of the present embodiment are as exemplified above, but the present invention is not limited to the dicing tape and the dicing die-bonding film exemplified above.

[0236] That is, various methods commonly used for dicing tapes and dicing die-bonding films can be adopted within a range that does not impair the effects of the present invention.

[0237] Example

[0238] Next, the present invention will be described in more detail with reference to experimental examples, but the present invention is not limited to these examples.

[0239] A dicing tape was produced as follows. A dicing die-bonding film was produced using the dicing tape.

[0240] <Base layer>

[0241] The examples had a three-layer structure (X layer / Y layer / X layer), while the comparative examples had a single layer structure (Y layer).

[0242] [Non-elastic layer: X layer]

[0243] Product Name: WXK1233, WMX03

[0244] Metallocene polypropylene random copolymer

[0245] WINTEC series manufactured by Japan Polypropylene Corp.

[0246] [Elastomer layer: Y layer]

[0247] Product Name: EV250, EV550

[0248] Ethylene vinyl acetate copolymer resin

[0249] EVAFLEX series manufactured by DOW-MITSUI POLYCHEMICALS

[0250] Product Name: Vistamaxx

[0251] Propylene elastomer resin

[0252] Vistamaxx series manufactured by ExxonMobil Japan

[0253] Molding conditions

[0254] A three-layer substrate layer structure of X / Y / X was produced using an extrusion T-die molding machine. Specifically, the layers were co-extruded and integrated through the T-die. After the extruded laminate was fully cured, it was wound into a roll to obtain a roll. The extrusion temperature conditions were as follows.

[0255] X layer (outer layer): 190℃

[0256] Y layer (inner layer): 190℃

[0257] Die temperature: 190℃

[0258] It should be noted that the thickness of the base material layer in each example and each comparative example is shown in Table 1.

[0259] <Adhesive layer>

[0260] (Synthesis of Acrylic Polymer)

[0261] The following raw materials were added to a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer, and a stirrer, and polymerization treatment was carried out at 60° C. for 10 hours in a nitrogen stream to synthesize an acrylic polymer intermediate.

[0262] 2-Ethylhexyl acrylate (hereinafter also referred to as "2EHA"): 100 parts by mass,

[0263] 2-Hydroxyethyl acrylate (hereinafter also referred to as "HEA"): 19 parts by mass,

[0264] Benzoyl peroxide: 0.4 parts by mass,

[0265] Toluene: 80 parts by mass

[0266] 1.2 parts by mass of 2-methacryloyloxyethyl isocyanate (hereinafter also referred to as "MOI") was added to the synthesized acrylic polymer intermediate, and an addition reaction treatment was performed at 50° C. for 60 hours in an air flow to synthesize an acrylic polymer.

[0267] (Preparation of Adhesive Layer)

[0268] Thereafter, a binder solution was prepared according to the following composition.

[0269] Synthetic acrylic polymer: 100 parts by mass,

[0270] Polyisocyanate compounds

[0271] (Product name: "Coronate L", manufactured by Nippon Polyurethane Co., Ltd.): 1.3 parts by mass,

[0272] Photopolymerization initiator

[0273] (Product name: "Irgacure 184", manufactured by Ciba Specialty Chemicals Co., Ltd.): 3 parts by mass

[0274] Prepare a PET film as a release sheet. Apply the adhesive solution prepared above to the release sheet. Note that one side of the release sheet (PET film) has been silicone-treated as a release treatment. Apply the adhesive solution to this release-treated surface. After application, heat at 120°C for 2 minutes to dry, creating a 10 μm thick adhesive layer on the release sheet.

[0275] <Production of Cutting Tape>

[0276] The exposed surface of the adhesive layer formed on the release sheet was bonded to each base layer and stored at 23° C. for 72 hours to produce a dicing tape.

[0277] <Chip Bonding Layer Fabrication>

[0278] The following (a) to (e) were dissolved in methyl ethyl ketone to prepare a resin composition having a solid content concentration of 20% by mass.

[0279] (a) Acrylic resin (product name: "SG-P3", manufactured by Nagase Chemical Co., Ltd., glass transition temperature: 12° C.): 100 parts by mass

[0280] (b) Epoxy resin (product name "JER1001" manufactured by Mitsubishi Chemical Corporation): 46 parts by mass

[0281] (c) Phenol resin (product name "MEH-7851ss", manufactured by Meiwa Chemicals Co., Ltd.) 51 parts by mass

[0282] (d) Spherical silica (product name "SO-25R" manufactured by Admatechs): 191 parts by mass

[0283] (e) Curing catalyst (product name: "CUREZOL 2PHZ" manufactured by Shikoku Chemical Industry Co., Ltd.): 0.6 parts by mass

[0284] The resin composition was applied to a 50 μm thick release film (release sheet) made of polyethylene terephthalate film that had been subjected to silicone release treatment. The film was then dried at 130°C for 2 minutes. This produced a die-bonding layer with an average thickness of 10 μm.

[0285] <Production of Dicing Die-Bond Film>

[0286] The PET release sheet was peeled off from the prepared dicing tape, and the die bonding layer was laminated onto the exposed adhesive layer. A manual roller was used for lamination. Afterwards, 300 mJ / cm was irradiated from the dicing tape side. 2 Thus, a dicing die bonding film is manufactured.

[0287] (Examples 1 to 6)

[0288] Base material layers having the configurations shown in Table 1 were prepared, and dicing tapes and dicing die-bonding films were manufactured according to the above-mentioned methods.

[0289] (Comparative Examples 1 to 4)

[0290] A base material layer having the structure shown in Table 1 was prepared, and a dicing tape and a dicing die-bonding film were manufactured in the same manner as in the examples.

[0291] Table 1 shows the configurations of the base material layers used for producing the dicing tapes and dicing die-bonding films of Examples and Comparative Examples.

[0292] Table 1 shows the physical properties (permanent deformation rate, etc.) of each dicing tape measured by the following method.

[0293] [Table 1]

[0294]

[0295] <Measurement of Permanent Deformation of Cutting Tape>

[0296] Each cutting tape manufactured as described above was cut into a width of 10 mm to prepare a sample. Then, the permanent deformation rate of the sample was measured as described below. In detail, the test was carried out using a tensile testing machine (product name "Tensilon", manufactured by Shimadzu Corporation) under the conditions of an initial distance between chucks of 50 mm and a stretching speed of 100 mm / min. It should be noted that in this measurement, stretching was performed along the MD direction, but it is not limited to this. Thereafter, it was stretched 100% (stretched to twice the length before stretching) at room temperature (23°C) or stretched 120% at -5°C and maintained for 1 minute. Thereafter, the tensile force was gradually relaxed at a rate of 100 mm / min, and the distance L between the chucks when the tension reached 0 was measured, and the percentage of L relative to the initial distance between the chucks was taken as the permanent deformation rate. The conceptual diagram of the measurement for obtaining the permanent deformation rate is shown in FIG. Figure 7 .

[0297] <Measurement of Elastic Modulus (Tensile Storage Modulus) of Dicing Tape>

[0298] Each cutting tape manufactured as above is overlapped until the thickness reaches 200 μm. Afterwards, it is cut into strips with a length of 40 mm (measurement length) and a width of 10 mm with a cutting knife. Next, the tensile storage modulus at -50 to 100 ° C is measured using a solid viscoelasticity measuring device (product name "RSAIII", manufactured by Rheometric Scientific). The measurement conditions are set to a frequency of 1 Hz, a heating rate of 10 ° C / min, and a distance of 22.5 mm between chucks. Read the values ​​at 23 ° C and 60 ° C, and use the read values ​​as the measured values ​​of the tensile storage modulus. The measured value obtained by implementing it once is used as the elastic modulus.

[0299] <Evaluation of Dicing Die-Bond Film Performance>

[0300] In the actual manufacture of semiconductor integrated circuits, wafers are often cut with circuits already formed on them (with the circuit layer formed). If a circuit layer with more space is formed, internal stress is more likely to occur, and the wafer as a whole is prone to some degree of warping. To evaluate performance under these conditions, a warp-adjusting layer (cured layer) that can cause warping is placed on the wafer. The warp-adjusting layer is placed on one side of the wafer to make it easier for the wafer to warp, and performance evaluation is conducted based on this as described below.

[0301] (Composition of the warp adjustment layer)

[0302] The following (a) to (f) were dissolved in methyl ethyl ketone to prepare a composition for a warp adjusting layer having a solid content concentration of 20% by mass.

[0303] (a) Acrylic resin (trade name "SG-70L", manufactured by Nagase Chemical Co., Ltd.): 5 parts by mass

[0304] (b) Epoxy resin (trade name "JER828" manufactured by Mitsubishi Chemical Corporation): 5 parts by mass

[0305] (c) 14 parts by mass of phenolic resin (trade name "LDR8210" manufactured by Meiwa Chemicals Co., Ltd.)

[0306] (d) Epoxy resin (trade name "MEH-8005" manufactured by Mitsubishi Chemical Corporation): 2 parts by mass

[0307] (e) Spherical silica (trade name "SO-25R", manufactured by Admatechs Corporation): 53 parts by mass

[0308] (f) Phosphorus-based catalyst (TPP-K): 1 part by mass

[0309] The above composition was applied onto a 50 μm thick release film (release liner) made of a polyethylene terephthalate film subjected to silicone release treatment and then dried at 130° C. for 2 minutes to prepare a warp adjustment layer having a thickness (average thickness) of 25 μm.

[0310] (Fabrication of Evaluation Wafers)

[0311] The warp adjustment layer prepared above was bonded to a wafer (a bare wafer without a circuit layer), and the release film was removed. The bonding conditions were 60°C, 0.1 MPa, and 10 mm / s. The warp adjustment layer was then cured by heating in an oven at 175°C for one hour.

[0312] Next, a wafer processing tape is attached to the exposed surface of the wafer and fixed to the dicing ring, and a groove is formed on the surface of the warp adjustment layer side (half-cut processing). Specifically, a dicing device (DFD6361, manufactured by DISCO) is used to form a 100μm deep groove in a lattice shape with a width of 20μm and a 4mm×11mm. Then, a back grinding tape is attached to the surface of the warp adjustment layer and the wafer processing tape is peeled off. The back side is then ground with a back grinding machine DGP8760 manufactured by DISCO until the total thickness of the laminate of the warp adjustment layer and the wafer is 55μm.

[0313] The exposed surface of the wafer is then attached to the die bond layer. Specifically, the surface of the wafer exposed after grinding is attached to the die bond layer laminated on the adhesive layer of the dicing tape fixed by the dicing ring, and the back grinding tape is peeled off.

[0314] (Extension method)

[0315] The semiconductor wafers were cut and the dicing tape was heat-shrunk using a die separation device (DDS2300, manufactured by DISCO Corporation).

[0316] Specifically, the semiconductor wafer and the chip bonding layer are first severed using a cold expansion unit at an expansion temperature of -15°C, an expansion speed of 200 mm / s, and an expansion distance of 12 mm.

[0317] Thereafter, the dicing tape was thermally shrunk (heated and shrunk) using a thermal expansion unit under the conditions of expansion amount 10 mm, heating temperature 250° C., air volume 40 L / min, heating distance 20 mm, and rotation speed 3° / sec.

[0318] (Incision Evaluation)

[0319] The incision was measured using a digital microscope (VHX-6000, manufactured by Keyence Corporation). For the measurement, after the thermal expansion was completed, the interval (incision) between the chips at the cut portion was observed with a digital microscope and the interval length was measured. The incisions in the MD direction and the TD direction were measured at 5 arbitrarily selected positions, and the minimum value of the measured value was used. If the incision is 30 or more, it is evaluated as ○, and if the incision is less than 30, it is evaluated as ×. It should be noted that the arbitrary 5 positions refer to: 4 positions located at the outermost portion of the circular wafer and approximately 90 degrees apart from each other in the circumferential direction, and near the center of the wafer.

[0320] From the above evaluation results, it was found that the dicing die-bonding film of the example could maintain the incision well after expansion, compared with the dicing die-bonding film of the comparative example.

[0321] The dicing tapes of Examples had a permanent deformation rate of 35% or more when stretched 100% at 23°C or 120% at -5°C.

[0322] The permanent set rate is an indicator of the susceptibility of the dicing tape to plastic deformation at a given temperature. A permanent set rate of 35% or higher indicates relatively suppressed elastic shrinkage after stretching. Therefore, it is believed that the less shrinkage after stretching, the more likely it is to maintain the cut after expansion.

[0323] In the dicing tape of the example, for example, the ratio (B / A) of the elastic modulus (B) at 60° C. to the elastic modulus (A) at 23° C. is 0.17 or more.

[0324] A ratio (B / A) of 0.17 or greater indicates that the elasticity at the higher temperature of 60°C (60°C) does not decrease significantly compared to the elasticity at 23°C. Therefore, even after the dicing tape is stretched and then heated to 60°C (e.g., heating and shrinking only the edges), the elasticity at the edges does not decrease significantly. This minimal decrease in the elasticity of the edges prevents the stretched dicing tape from returning to its original shape. This suggests that the dicing tape, while supporting the severed wafers, can maintain its cuts sufficiently after being stretched.

[0325] Industrial applicability

[0326] The dicing tape and dicing die-bonding film of the present invention can be suitably used as auxiliary tools in manufacturing semiconductor integrated circuits, for example.

Claims

1. A dicing tape comprising: a base material layer, and an adhesive layer superimposed on the base material layer, The substrate layer is composed of the following three layers: two non-elastic layers each formed of metallocene polypropylene, and an elastomer layer disposed between the two non-elastic layers and formed of ethylene-vinyl acetate copolymer or α-olefin-based thermoplastic elastomer. The thickness of the substrate layer is 60 μm or more and 160 μm or less. The ratio of the thickness of one of the non-elastic layers to the thickness of the elastomer layer is 0.05 or more and 0.25 or less. The permanent deformation rate of the cutting tape when stretched at 23°C is 35% or more, Regarding the elastic modulus of the dicing tape measured by a dynamic viscoelastic tensile test, The ratio of the elastic modulus B at 60°C to the elastic modulus A at 23°C, i.e., B / A, is 0.17 or more. The elastic modulus A at 23°C is 40 MPa or more and 300 MPa or less, and the elastic modulus B at 60°C is 8 MPa or more and 100 MPa or less, The elastic modulus C at 100° C. is 0.5 MPa or more and 20 MPa or less.

2. A dicing tape comprising a base layer and an adhesive layer superimposed on the base layer, The substrate layer is composed of the following three layers: two non-elastic layers each formed of metallocene polypropylene, and an elastomer layer disposed between the two non-elastic layers and formed of ethylene-vinyl acetate copolymer or α-olefin-based thermoplastic elastomer. The thickness of the substrate layer is 60 μm or more and 160 μm or less. The ratio of the thickness of one of the non-elastic layers to the thickness of the elastomer layer is 0.05 or more and 0.25 or less. The permanent deformation rate of the cutting tape when stretched at -5°C is 35% or more, Regarding the elastic modulus of the dicing tape measured by a dynamic viscoelastic tensile test, The ratio of the elastic modulus B at 60°C to the elastic modulus A at 23°C, i.e., B / A, is 0.17 or more. The elastic modulus A at 23°C is 40 MPa or more and 300 MPa or less, and the elastic modulus B at 60°C is 8 MPa or more and 100 MPa or less, The elastic modulus C at 100° C. is 0.5 MPa or more and 20 MPa or less. 3 . A dicing die-bonding film comprising: the dicing tape according to claim 1 ; and a die-bonding layer laminated on the adhesive layer of the dicing tape.

Images