Die bonding sheet and dicing die bonding film

Abstract

A die bonding sheet and a dicing die bonding film are provided. A die bonding sheet having a peeling force of 0.1 N / 50 mm or more relative to a polyimide resin surface is provided. In addition, a dicing die bonding film is provided, which comprises: the die bonding sheet and a dicing tape attached to the die bonding sheet.

Description

Technical Field

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

[0002] In the past, a dicing die bonding film used in the manufacture of semiconductor integrated circuits is known. Such a dicing die bonding film, for example, comprises: a dicing tape, and a die bonding sheet laminated on the dicing tape and bonded to a wafer. The dicing tape has a base material layer and an adhesive layer in contact with the die bonding sheet. Such a dicing die bonding film is 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 process of forming a circuit surface on one side of a wafer with a highly integrated electronic circuit, and a back process of cutting out chips from the wafer with the circuit surface formed thereon and assembling them.

[0004] The post-process includes, for example, the following processes: a dicing process, in which grooves are formed on the wafer in order to cut the wafer into small chips (die); a mounting process, in which the surface of the wafer opposite to the circuit surface is attached to the die bonding sheet and the wafer is fixed to the dicing tape; an expansion process, in which the wafer with the grooves formed is cut together with the die bonding sheet to increase the interval between the chips; a pick-up process, in which the die (die) attached with the die bonding sheet is peeled off from the adhesive layer and the die (die) is taken out; and a die bonding process, in which the die (die) attached with the die bonding sheet is bonded to the adherend. Semiconductor integrated circuits are manufactured through these processes.

[0005] In the semiconductor integrated circuit manufacturing method described above, in order to improve the performance of the pickup process and the chip bonding process, there is known a chip bonding sheet containing a thermoplastic resin component and a thermosetting resin component at a specific content ratio and having a surface free energy within a specific range (for example, Patent Document 1).

[0006] Specifically, in the die bonding sheet described in Patent Document 1, the thermoplastic resin component accounts for 15 to 30% by weight of the organic resin component, and the thermosetting resin component accounts for 60 to 70% by weight. In addition, the surface free energy is 37 mJ / m 2 Above and less than 40mJ / m 2 .

[0007] The die-bonding sheet described in Patent Document 1 can exhibit good releasability with the adhesive layer in the pickup step and can exhibit good adhesion with an adherend in the die-bonding step.

[0008] However, with the further development of integration technology in recent years, for example, in the above-mentioned die bonding process, relatively thin chips (dies) with die bonding sheets attached thereto may be stacked multiple times.

[0009] However, when chips (dies) with die-bonding sheets attached thereto are stacked as described in Patent Document 1, so-called floating may occur due to poor bonding between the die-bonding sheet and the chip (die).

[0010] In order to prevent such a problem, there is a strong demand for the development of a die bonding sheet capable of suppressing floating when stacking chips (dies).

[0011] Prior art literature

[0012] Patent Literature

[0013] Patent Document 1: Japanese Patent Application Publication No. 2008-244463 Summary of the invention

[0014] Problem that the invention aims to solve

[0015] However, it cannot be said that sufficient research has been conducted on a die-bonding sheet capable of suppressing floating when stacking chips (dies) and a dicing die-bonding film including the die-bonding sheet.

[0016] Therefore, an object of the present invention is to provide a die-bonding sheet and a dicing die-bonding film capable of suppressing floating when stacking chips (dies).

[0017] Solutions for solving problems

[0018] In order to solve the above-mentioned problems, the die-bonding sheet of the present invention has a peeling force of 0.1 N / 50 mm or more with respect to a polyimide resin surface.

[0019] According to the die bonding sheet having the above configuration, it is possible to suppress floating when stacking chips (dies).

[0020] The above-mentioned die bonding sheet preferably has a surface free energy of 35 mJ / m 2 The ratio of the dispersion component in the surface free energy is 95% or more. This can more fully suppress floating when stacking chips (dies).

[0021] The die-bonding sheet preferably has a contact angle of 90° or more with water and a contact angle of 50° or more with diiodomethane, thereby more sufficiently suppressing floating when stacking dies.

[0022] The dicing die-bonding film of the present invention includes the above-mentioned die-bonding sheet and a dicing tape bonded to the die-bonding sheet.

[0023] Effects of the Invention

[0024] The die-bonding sheet and the dicing die-bonding film of the present invention exhibit an effect of being able to suppress floating when stacking chips (dies). BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a cross-sectional view of the dicing die-bonding film of the present embodiment cut along the thickness direction.

[0026] Figure 2 A is a cross-sectional view schematically showing a half-cut process in a method for manufacturing a semiconductor integrated circuit.

[0027] Figure 2 B is a cross-sectional view schematically showing a half-cutting process in the method for manufacturing a semiconductor integrated circuit.

[0028] Figure 2 C is a cross-sectional view schematically showing a half-cutting process in the method for manufacturing a semiconductor integrated circuit.

[0029] Figure 2 D is a cross-sectional view schematically showing a half-cutting process in the method for manufacturing a semiconductor integrated circuit.

[0030] Figure 3 A is a cross-sectional view schematically showing a mounting step in a method for manufacturing a semiconductor integrated circuit.

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

[0032] Figure 4 A is a cross-sectional view schematically showing a low-temperature expansion step in a method for manufacturing a semiconductor integrated circuit.

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

[0034] Figure 4 C is a cross-sectional view schematically showing a state of a low-temperature expansion step in a method for manufacturing a semiconductor integrated circuit.

[0035] Figure 5 A is a cross-sectional view schematically showing an expansion step at room temperature in a method for manufacturing a semiconductor integrated circuit.

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

[0037] Figure 6 This is a cross-sectional view schematically showing a pickup step in a method of manufacturing a semiconductor integrated circuit.

[0038] Figure 7 The figure is a cross-sectional view schematically showing a state when chips (dies) are stacked.

[0039] Description of Reference Numerals

[0040] 1: Cutting die bonding film,

[0041] 10: Chip bonding sheet,

[0042] 20: cutting belt,

[0043] 21: base material layer,

[0044] 22: Adhesive layer. DETAILED DESCRIPTION

[0045] Hereinafter, embodiments of a die-bonding sheet and a dicing die-bonding film including the die-bonding sheet of the present invention will be described with reference to the drawings.

[0046] The dicing die-bonding film 1 of this embodiment is as follows Figure 1 As shown, it includes a dicing tape 20 and a die-bonding sheet 10 laminated on the dicing tape 20 and bonded to the semiconductor wafer. The die-bonding sheet 10 is bonded to an adherend such as a circuit board or a semiconductor chip in the manufacture of a semiconductor integrated circuit.

[0047] <Die-bonding sheet of dicing die-bonding film>

[0048] The peeling force of the chip bonding sheet 10 relative to the polyimide resin surface is 0.1N / 50mm or more. When the peeling force is less than 0.1N / 50mm, there is a concern that the floating of the stacked chips (die) cannot be suppressed. It should be noted that when the chip bonding sheet 10 is to be cured by heating or the like, the peeling force is the value before the curing treatment. In addition, the peeling force is the peeling force of the surface (the surface bonded to the adherend) of the chip bonding sheet 10 that is bonded to the adhesive layer 22 (described in detail later).

[0049] The above-mentioned peeling force is measured by the method described in Examples.

[0050] The polyimide resin surface used to measure the peeling force of the above-mentioned die-bonding sheet 10 is a surface of a specific polyimide resin film.

[0051] The physical properties of the polyimide resin film used for measurement are as follows: A polyimide resin film having the following physical properties was used for the measurement of the peeling force.

[0052] Static friction coefficient: 0.48 (JIS K 7125)

[0053] Dynamic friction coefficient: 0.42 (JIS K 7125)

[0054] Surface roughness [Ra]: 0.03~0.07μm (JIS B 0601)

[0055] Density [g·cm -3 ]:1.42(Archimedes method)

[0056] In principle, a polyimide resin film for measurement is used that is commercially available at the time of filing the present application and is manufactured by DU PONT-TORAY CO., LTD. and has a product name of “Kapton 100H”.

[0057] The surface free energy of the polyimide resin surface used in the above-mentioned peel force measurement is usually 25 mJ / m 2 Above and 35mJ / m 2 and the ratio of the dispersed component to the surface free energy is 85% or more and 95% or less.

[0058] The peeling force may be 0.2 N / 50 mm or more. When the peeling force is 0.2 N / 50 mm or more, it is possible to more fully suppress the floating when stacking chips (dies).

[0059] In addition, the above-mentioned peeling force may be 0.5 N / 50 mm or less.

[0060] For example, the above-mentioned peeling force can be increased by increasing the content ratio of thermoplastic resin and thermosetting resin and reducing the content ratio of inorganic filler. On the other hand, the above-mentioned peeling force can be reduced by reducing the content ratio of thermoplastic resin and thermosetting resin and increasing the content ratio of inorganic filler.

[0061] For the die bond sheet 10, the surface free energy is preferably 35 mJ / m 2 and the ratio of the dispersed component in the surface free energy is 95% or more.

[0062] By making the above surface free energy 35mJ / m 2 If the ratio of the dispersed component is 95% or more, there is an advantage that floating when stacking chips (dies) can be more sufficiently suppressed.

[0063] The surface free energy can be 25mJ / m 2 Above, 30mJ / m 2 above.

[0064] The above-mentioned method for measuring the surface free energy will be described in detail.

[0065] The surface free energy is calculated from the contact angle measurement results performed as follows: Specifically, the contact angles of water (H2O) and diiodomethane (CH2I2) droplets in contact with the surface of the die-bonding sheet 10 are measured using a contact angle meter at 20°C and 65% relative humidity.

[0066] Next, the surface free energy was calculated as follows based on the measured values ​​of the contact angle θw of water and the contact angle θi of diiodomethane. Specifically, γs was calculated according to the method of Owens et al. described in Journal of Applied Polymer Science, vol. 13, p1741-1747 (1969). d (dispersion component of surface free energy) and γs h (Polar component of surface free energy).

[0067] Then, γs d and γs h The sum of the values ​​γs(=γs d +γs h ) is the surface free energy of the die bonding sheet 10.

[0068] γs d (dispersed component) and γs h The values ​​of each (polar component) are obtained as solutions to the following two-variable simultaneous equations of formula (1) and formula (2). In formula (1) and (2), γw is the surface free energy of water, γw is d is the dispersion component of the surface free energy of water, γw h is the polar component of the surface free energy of water, γi is the surface free energy of methyl iodide, and γi d is the dispersion component of the surface free energy of methyl iodide, γi h is the polar component of the surface free energy of methyl iodide, and is a known value as described below.

[0069] γw=72.8[mJ / m 2 ]

[0070] γ d =21.8[mJ / m 2 ]

[0071] γ h =51.0[mJ / m 2]

[0072] γi=50.8[mJ / m 2 ]

[0073] γi d =48.5[mJ / m 2 ]

[0074] γi h =2.3[mJ / m 2 ]

[0075]

[0076]

[0077] The surface of the die-bonding sheet 10 preferably has a contact angle with water of 90° or more and a contact angle with diiodomethane of 50° or more.

[0078] This has the advantage of being able to more fully suppress floating when stacking chips (dies).

[0079] The contact angle of the surface of the die-bonding sheet 10 with water is preferably 95° or more. This has the advantage of being able to more fully suppress floating when stacking dies.

[0080] The surface of the die-bonding sheet 10 may have a contact angle with water of 110° or less.

[0081] The surface of the die-bonding sheet 10 preferably has a contact angle with diiodomethane of 52° or more. This has the advantage of being able to more fully suppress floating when stacking dies.

[0082] The contact angle of the surface of the die-bonding sheet 10 with diiodomethane may be 60° or less.

[0083] In this specification, surface free energy is divided into dispersed components and polar components as described above. Usually, the dispersed components of surface free energy are physical quantities that reflect the density, molecular weight, hardness, etc. of a substance. For example, in the surface free energy of an oxide or a metal, the dispersed components are low, while the dispersed components in the case of an organic material are high. In contrast, the polar component is a physical quantity that reflects the density or activity of polar groups on the surface. The dispersed components of a solid surface are not "zero", but the polar components can be "zero". If each component is considered in terms of the intermolecular interactions between the surfaces, the dispersed components are expressed as the Coulomb attraction between two non-polar molecules (dipoles), which is called the London dispersion energy. On the other hand, the polar components are called the permanent dipole (Keesom) energy and the permanent dipole-non-polar dipole (Debye) energy.

[0084] The surface free energy of the die bonding sheet 10 preferably has a dispersed component ratio of 97% or more. By increasing the dispersed component ratio, the wettability and spreadability of the die bonding sheet 10 on a common adherend is further improved. It should be noted that the dispersed component ratio may be 100% or less.

[0085] It should be noted that the above-mentioned dispersion component can be 25mJ / m 2 Above and 35mJ / m 2 the following.

[0086] In order to reduce the above-mentioned surface free energy and to increase the contact angle with water and diiodomethane, for example, as the raw material (resin, etc.) mixed in the chip bonding sheet 10, a raw material with lower polarity is selected, or the mixing ratio of the raw material with lower polarity is increased. On the other hand, in order to increase the above-mentioned surface free energy and to reduce the contact angle with water and diiodomethane, for example, as the raw material (resin, etc.) mixed in the chip bonding sheet 10, a raw material with higher polarity is selected, or the mixing ratio of the raw material with higher polarity is increased.

[0087] The die-bonding sheet 10 may include at least one of a thermosetting resin and a thermoplastic resin. The die-bonding sheet 10 preferably includes a thermosetting resin and a thermoplastic resin.

[0088] As the thermosetting resin, for example, epoxy resin, phenolic resin, amino resin, unsaturated polyester resin, polyurethane resin, silicone resin, thermosetting polyimide resin, etc. can be cited. As the above-mentioned thermosetting resin, only one kind or two or more kinds can be used. From the perspective of containing less ionic impurities that may cause corrosion of the semiconductor chip to be chip-bonded, epoxy resin is preferred as the above-mentioned thermosetting resin. As a curing agent for epoxy resin, phenolic resin is preferred.

[0089] 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, dicyclopentadiene type, phenol novolac type, o-cresol novolac type, trihydroxyphenylmethane type, tetraphenolylethane type, hydantoin type, triglycidyl isocyanurate type, and glycidylamine type epoxy resins.

[0090] The phenolic resin can function as a curing agent for the epoxy resin. Examples of the phenolic resin include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrene such as polyoxystyrene.

[0091] Examples of the novolac-type phenolic resin include phenol novolac resin, phenol aralkyl resin, cresol novolac resin, tert-butylphenol novolac resin, and nonylphenol novolac resin.

[0092] As the phenol resin, only one type may be used or two or more types may be used.

[0093] In the die-bonding sheet 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. This allows the curing reaction of the epoxy resin and the phenol resin to proceed sufficiently.

[0094] When the die bonding sheet 10 contains a thermosetting resin, the content ratio of the thermosetting resin in the die bonding sheet 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 bonding sheet 10. Thus, the die bonding sheet 10 can appropriately function as a thermosetting adhesive.

[0095] As thermoplastic resins that can be included in the chip bonding sheet 10, for example, 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-polyamide resin, 6,6-polyamide resin and other polyamide resins, phenoxy resin, acrylic resin, saturated polyester resins such as PET and PBT, polyamide-imide resin, fluororesin, etc.

[0096] As the thermoplastic resin, acrylic resin is preferable because it contains less ionic impurities and has high heat resistance, thereby further ensuring the adhesiveness of the die-bonding sheet 10 .

[0097] As the above-mentioned thermoplastic resin, only one kind may be used or two or more kinds may be used.

[0098] The acrylic resin is preferably a polymer in which the mass ratio of the structural unit of the (meth)acrylic acid alkyl ester is the largest among the structural units in the molecule. Examples of the (meth)acrylic acid alkyl ester include C2 to C4 alkyl (meth)acrylates.

[0099] The acrylic resin may include a structural unit derived from other monomer components copolymerizable with the alkyl (meth)acrylate monomer.

[0100] 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.

[0101] For the above-mentioned acrylic resin, from the perspective of enabling the chip bonding sheet 10 to exert a higher cohesive force, a copolymer of an alkyl (meth)acrylate (especially an alkyl (meth)acrylate 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-based polyfunctional monomer) is preferred, and a copolymer of ethyl acrylate, butyl acrylate, acrylic acid, acrylonitrile and polyglycidyl (meth)acrylate is more preferred.

[0102] The acrylic resin is preferably an acrylic resin having an acrylonitrile content of 10% by mass or less. This has the advantage of being able to further reduce the ratio of polar components in the surface free energy of the die-bonding sheet 10 .

[0103] The glass transition temperature (Tg) of the acrylic resin is preferably -50°C to 50°C, and more preferably 10°C to 30°C, from the viewpoint of easily setting the elasticity and viscosity of the die-bonding sheet 10 within a desired range.

[0104] When the chip bonding sheet 10 includes a thermosetting resin and a thermoplastic resin, the content ratio of the above-mentioned thermoplastic resin in the chip bonding sheet 10 is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, and further preferably 20% by mass or more and 40% by mass or less, relative to the total mass of the organic components (e.g., thermosetting resin, thermoplastic resin, curing catalyst, silane coupling agent, dye) excluding fillers. It should be noted that by changing the content ratio of the thermosetting resin, the elasticity and viscosity of the chip bonding sheet 10 can be adjusted.

[0105] When the thermoplastic resin of the die bonding sheet 10 has a thermosetting functional group, as the thermoplastic resin, for example, an acrylic resin containing a thermosetting functional group can be used. The acrylic resin containing a thermosetting functional group preferably contains a structural unit derived from an alkyl (meth)acrylate in the molecule at the largest mass ratio. As the alkyl (meth)acrylate, for example, the alkyl (meth)acrylate esters exemplified above can be cited.

[0106] 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.

[0107] The die bonding sheet 10 preferably comprises an acrylic resin containing a thermosetting functional group and a curing agent. When the thermosetting functional group in the acrylic resin containing a thermosetting functional group is a glycidyl group, a compound having a plurality of phenol structures is preferably used as the curing agent. For example, the various phenolic resins described above can be used as the curing agent.

[0108] The die-bonding sheet 10 preferably contains a filler. By changing the amount of the filler in the die-bonding sheet 10 , the elasticity and viscosity of the die-bonding sheet 10 can be more easily adjusted. Furthermore, the physical properties of the die-bonding sheet 10 , such as electrical conductivity, thermal conductivity, and elastic modulus, can be adjusted.

[0109] Examples of the filler include inorganic fillers and organic fillers. As the filler, an inorganic filler is preferred.

[0110] As the inorganic filler, for example, 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, amorphous silicon dioxide, etc. can be cited. In addition, as the material of the inorganic filler, metal single substances, alloys, etc. such as aluminum, gold, silver, copper, and nickel can be cited. Fillers such as aluminum borate whiskers, amorphous carbon black, and graphite can be used. The shape of the filler can be various shapes such as spherical, needle-shaped, and flaky. As the filler, only one of the above-mentioned or more than two can be used.

[0111] The average particle size 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 making the average particle size 0.005 μm or more, the wettability and adhesion to adherends such as semiconductor wafers are further improved. By making the average particle size 10 μm or less, the characteristics of the added filler can be more fully utilized, and the heat resistance of the chip bonding sheet 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", HORIBA, Ltd.).

[0112] When the die bonding sheet 10 contains fillers, the content ratio of the fillers is preferably 30 mass % to 70 mass % with respect to the total mass of the die bonding sheet 10 , more preferably 40 mass % to 60 mass %, and further preferably 42 mass % to 55 mass %.

[0113] The die-bonding sheet 10 may contain other components as necessary. Examples of the other components include a curing catalyst, a flame retardant, a silane coupling agent, an ion scavenger, and a dye.

[0114] Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resins.

[0115] Examples of the silane coupling agent include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane.

[0116] Examples of the ion scavenger include hydrotalcites, bismuth hydroxide, and benzotriazole.

[0117] As the other additives, only one kind may be used or two or more kinds may be used.

[0118] The die-bonding sheet 10 preferably contains a thermoplastic resin (particularly an acrylic resin), a thermosetting resin, and a filler from the viewpoint of facilitating adjustment of elasticity and viscosity.

[0119] The thickness of the die bond sheet 10 is not particularly limited, and is, for example, 1 μm to 200 μm. The thickness may be 3 μm to 150 μm, or 5 μm to 100 μm. When the die bond sheet 10 is a laminate, the above thickness is the total thickness of the laminate.

[0120] The die bond sheet 10 is, for example, Figure 1 As shown, it may have a single-layer structure. In this specification, a single layer means a layer consisting of only one composition. A plurality of layers consisting of the same composition are stacked and formed into a single layer.

[0121] On the other hand, the die-bonding sheet 10 may have a multilayer structure in which layers formed of two or more different compositions are stacked, for example.

[0122] The dicing die bonding film 1 of the present embodiment is irradiated with active energy rays (e.g., ultraviolet rays) during use, thereby curing the adhesive layer 22. Specifically, in a state where the die bonding sheet 10 having a semiconductor wafer bonded to one side and the adhesive layer 22 bonded to the other side of the die bonding sheet 10 are stacked, at least the adhesive layer 22 is irradiated with ultraviolet rays or the like. For example, ultraviolet rays or the like are irradiated from the side where the base material layer 21 is arranged, and the ultraviolet rays or the like that pass through the base material layer 21 reach the adhesive layer 22. The adhesive layer 22 is cured by irradiation with ultraviolet rays or the like.

[0123] The adhesive layer 22 is cured after irradiation, thereby reducing the adhesive force of the adhesive layer 22 . Therefore, the die-bonding sheet 10 (in a state where the semiconductor wafer is bonded) can be relatively easily peeled from the adhesive layer 22 after irradiation.

[0124] The dicing die bonding film 1 of the present embodiment may have a release sheet covering one surface of the die bonding sheet 10 (the surface of the die bonding sheet 10 that does not overlap with the adhesive layer 22) before use. The release sheet is used to protect the die bonding sheet 10 and is peeled off before attaching an adherend (e.g., a semiconductor wafer) to the die bonding sheet 10.

[0125] 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 sheet 10. The release sheet is suitable for use when the chip bonding sheet 10 is overlapped on the adhesive layer 22. In detail, the chip bonding sheet 10 is overlapped on the adhesive layer 22 in a state where the release sheet overlaps with the chip bonding sheet 10, and the release sheet is peeled off (transferred) after overlapping, thereby enabling the chip bonding sheet 10 to be overlapped on the adhesive layer 22.

[0126] Since the die-bonding sheet 10 of the present embodiment is configured as described above, it is possible to suppress floating (chip floating phenomenon) when chips (dies) are stacked.

[0127] Next, embodiments of the dicing die-bonding film of the present invention will be described.

[0128] The dicing die-bonding film 1 of the present embodiment includes the above-mentioned die-bonding sheet 10 and a dicing tape bonded to the die-bonding sheet 10 .

[0129] <Dicing tape for dicing die-bonding film>

[0130] The dicing tape 20 is usually a long sheet and is stored in a rolled state until use. The dicing die-bonding film 1 of the present embodiment is attached to a ring-shaped frame having an inner diameter slightly larger than the silicon wafer to be cut and used.

[0131] The dicing tape 20 described above includes a base material layer 21 and an adhesive layer 22 laminated on the base material layer 21 .

[0132] The base material layer 21 may have a single-layer structure or a laminated structure.

[0133] 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.

[0134] Examples of the fiber sheet constituting the base layer 21 include paper, woven fabric, and nonwoven fabric.

[0135] As the material of the resin film, for example, polyolefins such as polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymers; copolymers of ethylene 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); polyacrylates; polyvinyl chloride (PVC); polyurethane; polycarbonate; polyphenylene sulfide (PPS); polyamides such as aliphatic polyamides and wholly aromatic polyamides (aramid); polyetheretherketone (PEEK); polyimide; polyetherimide; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymer); cellulose or cellulose derivatives; silicone-containing polymers; fluorine-containing polymers, etc. These can be used alone or in combination of two or more.

[0136] The base material layer 21 is preferably made of a polymer material such as a resin film.

[0137] 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.

[0138] The surface of the base material layer 21 may be subjected to a surface treatment in order to improve adhesion with the adhesive layer 22. As the surface treatment, for example, an 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, etc. may be adopted. In addition, a coating treatment using a coating agent such as an anchor coating agent, a primer, or an adhesive may be performed.

[0139] 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.

[0140] The three-layered substrate layer 21 preferably includes two non-elastic layers (X, X) formed of a non-elastic body and an elastic layer (Y) arranged between the two non-elastic layers and formed of an elastomer (X layer / Y layer / X layer).

[0141] The elastic layer is a layer having an elastic modulus of 200 MPa or less at room temperature. The elastic layer is generally formed of a polymer material showing rubber elasticity at room temperature (23° C.). On the other hand, the non-elastic layer is a layer having an elastic modulus of more than 200 MPa at room temperature.

[0142] Each layer of the elastic body having such a three-layer laminated structure is usually formed of a resin. The elastic body having a three-layer laminated structure is produced by, for example, co-extrusion molding, and the three layers are integrated.

[0143] In the three-layered base material layer 21 , the ratio of the thickness of the inner layer to the thickness of one outer layer (Y thickness / X thickness) is preferably 5 or more and 15 or less.

[0144] The non-elastic layer disposed on the outside preferably has a molecular weight distribution dispersion (mass average molecular weight / number average molecular weight) of 3 or less when the constituent resin is measured by GPC.

[0145] The non-elastomer layer (X) may include low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene, etc. As polypropylene, homopolymers (homopolypropylene), or copolymers such as random polypropylene and block polypropylene, etc. may be cited. Polypropylene may be metallocene polypropylene synthesized using a metallocene catalyst. The non-elastomer layer (X) preferably includes metallocene polypropylene.

[0146] On the other hand, the elastomer layer (Y) preferably comprises ethylene-vinyl acetate copolymer (EVA) or α-olefin-based thermoplastic elastomer, and more preferably comprises ethylene-vinyl acetate copolymer (EVA). Examples of α-olefin-based thermoplastic elastomers include homopolymers of α-olefins and copolymers of two or more α-olefins.

[0147] The ethylene-vinyl acetate copolymer resin (EVA) may contain 5% by mass or more and 35% by mass or less of a vinyl acetate structural unit.

[0148] The thickness (total thickness) of the base material layer 21 may be 80 μm or more and 150 μm or less.

[0149] In order to impart releasability, for example, the back side of the base layer 21 (the side not overlapping the pressure-sensitive 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.

[0150] The base material layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like in that active energy rays such as ultraviolet rays can be applied to the pressure-sensitive adhesive layer 22 from the back side.

[0151] The dicing tape 20 described above may have a release sheet covering one side of the adhesive layer 22 (the side where the adhesive layer 22 does not overlap with the base layer 21) before use. When the chip bonding sheet 10 having a smaller area than the adhesive layer 22 is accommodated and arranged in the adhesive layer 22, the release sheet is arranged in a manner covering both the adhesive layer 22 and the chip bonding sheet 10. The release sheet is used to protect the adhesive layer 22 and is peeled off before the chip bonding sheet 10 is attached to the adhesive layer 22.

[0152] As the release sheet, for example, a plastic film or paper that has been surface-treated with a release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide release agent can be used.

[0153] In addition, as a peeling sheet, for example, 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; films made of polyesters such as polyethylene terephthalate (PET), etc. can be used.

[0154] As the release sheet, for example, a plastic film or paper whose surface is coated with a release agent such as a fluorine-based release agent or a long-chain alkyl acrylate-based release agent can be used.

[0155] It should be noted that the release sheet can be used as a supporting material for supporting the adhesive layer 22. In particular, the release sheet is suitable for use when the adhesive layer 22 is overlapped on the base layer 21. Specifically, the adhesive layer 22 is overlapped on the base layer 21 in a state where the release sheet and the adhesive layer 22 are stacked, and the release sheet is peeled off (transferred) after the overlap, thereby enabling the adhesive layer 22 to be overlapped on the base layer 21.

[0156] In the present embodiment, the adhesive layer 22 contains, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator.

[0157] The adhesive layer 22 may have a thickness of 5 μm or more and 40 μm or less. The shape and size of the adhesive layer 22 are usually the same as those of the base layer 21 .

[0158] The acrylic polymer has at least a structural unit of an alkyl (meth)acrylate, a structural unit of a hydroxyl group-containing (meth)acrylate, and a structural unit of a (meth)acrylate containing a polymerizable group in the molecule. The structural unit is a unit constituting the main chain of the acrylic polymer. Each side chain in the acrylic polymer is included in each structural unit constituting the main chain.

[0159] In addition, in this specification, the expression "(meth)acrylate" means at least one of methacrylate and acrylate. Similarly, the expression "(meth)acrylic acid" means at least one of methacrylic acid and acrylic acid.

[0160] For the acrylic polymer contained in the adhesive layer 22, the above structural units can be 1 H-NMR, 13 The molar ratio of the above structural units in the acrylic polymer is usually calculated from the amount (charge amount) of the acrylic polymer when it is polymerized.

[0161] The structural unit of the alkyl (meth)acrylate is derived from the alkyl (meth)acrylate monomer. In other words, the molecular structure after the polymerization reaction of the alkyl (meth)acrylate monomer is the structural unit of the alkyl (meth)acrylate. The expression "alkyl" indicates the carbon number of the hydrocarbon part that is ester-bonded to the (meth)acrylic acid.

[0162] The hydrocarbon portion of the alkyl portion in the structural unit of the alkyl (meth)acrylate may be a saturated hydrocarbon or an unsaturated hydrocarbon.

[0163] It should be noted that the alkyl portion preferably does not have polar groups containing oxygen (O), nitrogen (N), etc. Thus, the polarity of the alkyl polymer can be suppressed from being extremely increased. Therefore, the adhesive layer 22 can be suppressed from having excessive affinity for the chip bonding sheet 10. Therefore, the dicing tape 20 can be peeled off from the chip bonding sheet 10 more well. The number of carbon atoms in the alkyl portion can be 6 or more and 10 or less.

[0164] Examples of the structural unit of the alkyl (meth)acrylate include structural units such as hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, and decyl (meth)acrylate.

[0165] The acrylic polymer has a structural unit of a hydroxyl group-containing (meth)acrylate, and the hydroxyl group of the structural unit easily reacts with an isocyanate group.

[0166] By allowing the acrylic polymer having a structural unit of a hydroxyl-containing (meth)acrylate and the isocyanate compound to coexist in the adhesive layer 22 in advance, the adhesive layer 22 can be appropriately cured. Therefore, the acrylic polymer can be fully saponified. Therefore, the adhesive layer 22 can maintain its shape and exhibit adhesive properties.

[0167] The structural unit of the hydroxyl-containing (meth)acrylate is preferably a structural unit of a hydroxyl-containing C2-C4 alkyl (meth)acrylate. The expression "C2-C4 alkyl" indicates the number of carbon atoms in the hydrocarbon portion that is ester-bonded to (meth)acrylic acid. In other words, the hydroxyl-containing C2-C4 alkyl (meth)acrylate monomer refers to a monomer in which (meth)acrylic acid is ester-bonded to an alcohol having 2 to 4 carbon atoms (usually a dihydric alcohol).

[0168] The hydrocarbon part of the C2-C4 alkyl group is usually a saturated hydrocarbon. For example, the hydrocarbon part of the C2-C4 alkyl group is a straight-chain saturated hydrocarbon or a branched saturated hydrocarbon. The hydrocarbon part of the C2-C4 alkyl group preferably does not have a polar group containing oxygen (O), nitrogen (N), etc.

[0169] As the structural unit of the hydroxyl group-containing C2-C4 alkyl (meth)acrylate, for example, there can be mentioned structural units of hydroxybutyl (meth)acrylate such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxyn-butyl (meth)acrylate, or hydroxyisobutyl (meth)acrylate. It should be noted that in the structural unit of hydroxybutyl (meth)acrylate, the hydroxyl group (-OH group) may be bonded to the carbon (C) at the terminal of the hydrocarbon part, or may be bonded to a carbon (C) other than the terminal of the hydrocarbon part.

[0170] 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.

[0171] The acrylic polymer contains a structural unit of (meth)acrylate containing a polymerizable group, so that the adhesive layer 22 can be cured by irradiation with active energy rays (ultraviolet rays, etc.) before the pickup process. In detail, by irradiation with active energy rays such as ultraviolet rays, free radicals are generated by the photopolymerization initiator, and the acrylic polymers can be cross-linked with each other through the action of the free radicals. Thus, the adhesive force of the adhesive layer 22 before irradiation can be reduced by irradiation. Then, the chip bonding sheet 10 can be well peeled off from the adhesive layer 22.

[0172] In addition, as active energy rays, ultraviolet rays, radiation rays, and electron beams can be used.

[0173] Specifically, the structural unit of the polymerizable group-containing (meth)acrylate may have a molecular structure in which a hydroxyl group in the structural unit of the hydroxyl group-containing (meth)acrylate and an isocyanate group of an isocyanate group-containing (meth)acrylate monomer are urethane-bonded.

[0174] The structural unit of the polymerizable group-containing (meth)acrylate having a polymerizable group can be prepared after polymerization of an acrylic polymer. For example, the structural unit of the polymerizable group-containing (meth)acrylate can be obtained by copolymerizing an alkyl (meth)acrylate monomer and a hydroxyl-containing (meth)acrylate monomer and subjecting a part of the structural unit of the hydroxyl-containing (meth)acrylate to a urethanization reaction with an isocyanate group of an isocyanate-containing polymerizable monomer.

[0175] The isocyanate group-containing (meth)acrylate monomer preferably has one isocyanate group and one (meth)acryloyl group in the molecule. Examples of the monomer include 2-isocyanatoethyl (meth)acrylate.

[0176] The adhesive layer 22 of the dicing tape 20 in the present embodiment further contains an isocyanate compound. A part of the isocyanate compound may be in a state after reacting by a urethanization reaction or the like.

[0177] The isocyanate compound has a plurality of isocyanate groups in the molecule. By making the isocyanate compound have a plurality of isocyanate groups in the molecule, a cross-linking reaction between acrylic polymers in the adhesive layer 22 can be performed. Specifically, some isocyanate groups of the isocyanate compound are reacted with hydroxyl groups of acrylic polymers, and other isocyanate groups are reacted with hydroxyl groups of other acrylic polymers, thereby enabling a cross-linking reaction via the isocyanate compound to be performed.

[0178] Examples of the isocyanate compound include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, and aromatic aliphatic diisocyanates.

[0179] Furthermore, examples of the isocyanate compound include polymeric polyisocyanates such as dimers and trimers of diisocyanates, and polymethylene polyphenylene polyisocyanates.

[0180] The isocyanate compound includes, for example, polyisocyanates obtained by reacting an excess amount of the above-mentioned isocyanate compound with an active hydrogen-containing compound. The active hydrogen-containing compound includes low molecular weight compounds containing active hydrogen, high molecular weight compounds containing active hydrogen, and the like.

[0181] In addition, as an isocyanate compound, allophanate polyisocyanate, biuret polyisocyanate, etc. can also be used.

[0182] The above-mentioned isocyanate compounds can be used alone or in combination of two or more.

[0183] As the above-mentioned isocyanate compound, the reaction product of an aromatic diisocyanate and a low molecular weight compound containing active hydrogen is preferred. The reaction rate of the isocyanate group of the reaction product of the aromatic diisocyanate is slow, so the adhesive layer 22 containing the reaction product can suppress overcuring. As the above-mentioned isocyanate compound, it is preferred that the isocyanate compound has three or more isocyanate groups in the molecule.

[0184] The polymerization initiator contained in the adhesive layer 22 is a compound that can initiate a polymerization reaction by applying heat or light energy. By making the adhesive layer 22 contain a polymerization initiator, a cross-linking reaction between acrylic polymers can be carried out when heat energy or light energy is applied to the adhesive layer 22. In detail, a polymerization reaction between polymerizable groups can be initiated between acrylic polymers having structural units of (meth)acrylates 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 sheet 10 can be easily peeled off from the cured adhesive layer 22 in the pickup process.

[0185] 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.

[0186] The adhesive layer 22 may also contain other components in addition to the above components. As other components, for example, tackifiers, plasticizers, fillers, antioxidants, antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, antistatic agents, surfactants, light peeling agents, etc. can be cited. The types and amounts of other components can be appropriately selected according to the purpose.

[0187] Next, a method for manufacturing the die-bonding sheet 10 and the dicing die-bonding film 1 according to the present embodiment will be described.

[0188] <Method for Manufacturing Dicing Die-Bond Film>

[0189] The method for manufacturing the dicing die-bonding film 1 according to the present embodiment includes:

[0190] A process for manufacturing the chip bonding sheet 10;

[0191] A process for making the cutting tape 20; and

[0192] A step of overlapping the manufactured die-bonding sheet 10 and the dicing tape 20 .

[0193] <Step of Manufacturing Die-Bond Sheet>

[0194] The process of manufacturing the die bond sheet 10 includes:

[0195] a resin composition preparation step of preparing a resin composition for forming the die-bonding sheet 10; and

[0196] In the die-bonding sheet forming step, the die-bonding sheet 10 is formed from the resin composition.

[0197] In the resin composition preparation process, for example, epoxy resin, epoxy resin curing catalyst, acrylic resin, phenolic resin, solvent, etc. are mixed, and each resin is dissolved in the solvent to prepare the resin composition. The viscosity of the composition can be adjusted by changing the amount of the solvent. It should be noted that commercially available products can be used as these resins.

[0198] In the chip bonding sheet forming process, for example, the resin composition prepared as described above is applied to the release sheet. As a coating method, there is no particular limitation, for example, a common coating method such as roller coating, screen coating, gravure coating, etc. can be adopted. Then, as needed, the coated composition is cured by desolventizing treatment, curing treatment, etc., thereby forming a chip bonding sheet 10.

[0199] <Process of Making Cutting Tape>

[0200] The process of making cutting tape includes:

[0201] A synthesis process for synthesizing acrylic polymers;

[0202] An adhesive layer preparation step of preparing the adhesive layer 22 by volatilizing the 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;

[0203] a base material layer manufacturing step of manufacturing the base material layer 21; and

[0204] In the lamination step, the adhesive layer 22 is bonded to the base layer 21 , thereby laminating the base layer 21 and the adhesive layer 22 .

[0205] In the synthesis step, for example, a (meth)acrylic acid C9-C11 alkyl ester monomer and a hydroxyl group-containing (meth)acrylic acid ester monomer are radically polymerized to synthesize an acrylic polymer intermediate.

[0206] Free radical polymerization can be carried out by a common method. For example, the above-mentioned monomers are dissolved in a solvent, stirred while heating, and a polymerization initiator is added, thereby synthesizing an acrylic polymer intermediate. In order to adjust the molecular weight of the acrylic polymer, the polymerization can be carried out in the presence of a chain transfer agent.

[0207] Next, a part of the hydroxyl groups of the structural unit of the hydroxyl group-containing (meth)acrylate contained in the acrylic polymer intermediate is bonded to the isocyanate group of the isocyanate group-containing polymerizable monomer by urethanization reaction. Thus, a part of the structural unit of the hydroxyl group-containing (meth)acrylate becomes a structural unit of the polymerizable group-containing (meth)acrylate.

[0208] The urethanization reaction can be carried out by a common method. For example, the acrylic polymer intermediate and the isocyanate group-containing polymerizable monomer are stirred while being heated in the presence of a solvent and a urethanization catalyst. In this way, a part of the hydroxyl group of the acrylic polymer intermediate can be urethanized with the isocyanate group of the isocyanate group-containing polymerizable monomer.

[0209] In the adhesive layer preparation process, for example, acrylic polymer, isocyanate compound and polymerization initiator are dissolved in solvent to prepare adhesive composition. By changing the amount of solvent, the viscosity of the composition can be adjusted. Then, the adhesive composition is applied to the release sheet. As a coating method, for example, the common coating methods such as roller coating, screen coating, gravure coating can be adopted. The applied composition is subjected to desolventizing treatment, curing treatment, etc., so that the applied adhesive composition is cured to make adhesive layer 22.

[0210] In the substrate layer preparation process, the substrate layer can be prepared by film formation by a common method. As a method for film formation, for example, a calendering film forming method, a casting method in an organic solvent, a blow molding extrusion method in a closed system, a T-die extrusion method, a dry lamination method, etc. can be cited. A coextrusion molding method can also be adopted. It should be noted that, as the substrate layer 21, a commercially available film, etc. can be used.

[0211] In the lamination step, the adhesive layer 22 in a state of being overlapped with the release sheet is laminated so as to overlap with the base layer 21. In addition, the release sheet may be in a state of being overlapped with the adhesive layer 22 until use.

[0212] In order 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.

[0213] Through these steps, the dicing tape 20 can be manufactured.

[0214] <Step of Overlaying the Die-Bond Sheet 10 and the Dicing Tape 20>

[0215] In the step of superimposing the die-bonding sheet 10 on the dicing tape 20 , the die-bonding sheet 10 is attached to the adhesive layer 22 of the dicing tape 20 manufactured as described above.

[0216] In the above-mentioned lamination, the release sheets are peeled off from the adhesive layer 22 of the dicing tape 20 and the chip bonding sheet 10, respectively, and the chip bonding sheet 10 is laminated to the adhesive layer 22 in such a way that the chip bonding sheet 10 is in direct contact with the adhesive layer 22. For example, lamination can be performed by crimping. The temperature during lamination is not particularly limited, for example, it is 30°C or more and 50°C or less, preferably 35°C or more and 45°C or less. The linear pressure during lamination is not particularly limited, preferably 0.1kgf / cm or more and 20kgf / cm or less, more preferably 1kgf / cm or more and 10kgf / cm or less.

[0217] The dicing die-bonding film 1 manufactured as described above through the above steps is used as an auxiliary tool for manufacturing a semiconductor integrated circuit, for example.

[0218] <Method of using dicing die-bonding film when manufacturing semiconductor integrated circuits>

[0219] The method of manufacturing a semiconductor integrated circuit generally includes a step of cutting out chips from a semiconductor wafer having a circuit surface formed thereon and assembling the chips.

[0220] This process includes, for example, the following processes: a half-cutting process, in which a groove is formed on the semiconductor wafer in order to process the semiconductor wafer into a chip (die) by cutting, and then the semiconductor wafer is ground to reduce the thickness; a mounting process, in which one side (for example, the side opposite to the circuit surface) of the semiconductor wafer processed by half-cutting is attached to the die bonding sheet 10 to fix the semiconductor wafer to the dicing tape 20; an expansion process, in which the interval between the semiconductor chips processed by half-cutting is enlarged; a picking process, in which the die bonding sheet 10 and the adhesive layer 22 are peeled off and the semiconductor die is taken out in a state where the die bonding sheet 10 is attached; and a die bonding process, in which the semiconductor die in a state where the die bonding sheet 10 is attached is bonded to the adherend. When performing these processes, the dicing tape (dicing die bonding film) of this embodiment is used as a manufacturing auxiliary tool.

[0221] In the half-cutting process, Figure 2 A~ Figure 2 As shown in D, a half-cutting process for cutting a semiconductor integrated circuit into small pieces (die) is performed. Specifically, a wafer processing tape T is attached to the surface of the semiconductor wafer W that is opposite to the circuit surface. In addition, a cutting ring R is mounted on the wafer processing tape T. A groove for dividing is formed with the wafer processing tape T attached. A back grinding tape G is attached to the surface with the groove formed, and the wafer processing tape T attached at the beginning is peeled off. A grinding process is performed with the back grinding tape G attached until the semiconductor wafer W reaches a specified thickness.

[0222] During the installation process, Figure 3 A~ Figure 3 As shown in FIG. 1B , a dicing ring R is attached to the adhesive layer 22 of the dicing tape 20 , and the semiconductor wafer W that has been half-cut is attached to the exposed surface of the die-bonding sheet 10 . Then, the back grinding tape G is peeled off from the semiconductor wafer W.

[0223] In the expansion process, Figure 4 A~ Figure 4 As shown in C, after the cutting ring R is installed on the adhesive layer 22 of the cutting tape 20, it is fixed to the retaining member 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 to expand it in the surface direction. Thus, the semiconductor wafer W that has been half-cut is cut under specific temperature conditions. The above-mentioned temperature conditions are, for example, -20 to 0°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 low-temperature expansion process). Furthermore, in the expansion process, as Figure 5 A~ Figure 5 As shown in B, the dicing tape 20 is stretched under a higher temperature condition (e.g., 10°C to 25°C) to expand the area. Thus, the adjacent semiconductor chips that have been cut are pulled apart in the surface direction of the film surface, and the slit (interval) is further expanded (normal temperature expansion process).

[0224] During the picking process, Figure 6 As shown, the semiconductor chip with the die-bonding sheet 10 attached thereto is peeled off from the adhesive layer 22 of the dicing tape 20. Specifically, the pin member P is raised to lift up the semiconductor chip to be picked up through the dicing tape 20. The lifted semiconductor chip is held by the suction jig J.

[0225] In the die bonding step, the semiconductor chip K to which the die bonding sheet 10 is attached is bonded to an adherend.

[0226] During the chip bonding process, Figure 7 As shown, the semiconductor chips K with the die-bonding sheet 10 attached thereto may be stacked multiple times.

[0227] In the first bonding, the die bonding sheet 10 is bonded to the substrate Z, and in the second or subsequent bonding, the die bonding sheet 10 is bonded to the surface (circuit surface) of the semiconductor chip K. The surface of the semiconductor chip K is coated with a specific resin (e.g., polyimide resin). Therefore, the bonding performance of the die bonding sheet 10 to the surface of the semiconductor chip K is affected by the above-mentioned coating process.

[0228] In this embodiment, it was found that the adhesive performance is related to the peeling force of the die-bonding sheet 10 to the polyimide resin surface. Furthermore, it was found that the adhesive performance is also related to the surface free energy of the die-bonding sheet 10 .

[0229] It should be noted that in the semiconductor industry in recent years, with the further progress of integration technology, there is an urgent need for thinner semiconductor chips (for example, a thickness of more than 20 μm and less than 50 μm). An electronic circuit is formed on one surface of such a thin semiconductor chip. If an electronic circuit is formed on one surface of a thin semiconductor chip, sometimes the semiconductor chip cannot withstand the internal stress and may deform slightly (warp, etc.). If such a semiconductor chip is stacked multiple times as described above with the chip bonding sheet 10 attached to it, sometimes, for example, Figure 7 As shown in FIG. 1 , so-called floating occurs due to poor bonding between the die-bonding sheet and the chip (die). In the present embodiment, the die-bonding sheet 10 has specific physical properties, and thus such floating can be suppressed.

[0230] Matters disclosed by this specification include the following. (1)

[0232] A die-bonding sheet having a peeling force with respect to a polyimide resin surface of 0.1 N / 50 mm or more and 0.5 N / 50 mm or less. (2)

[0234] The die-bonding sheet according to (1) above, wherein the surface free energy of the polyimide resin surface used in the measurement of the peel force is 25 mJ / m 2 Above and 35mJ / m 2 and the ratio of the dispersed component to the surface free energy is 85% to 95%. (3)

[0236] The die-bonding sheet according to (1) or (2) above, wherein the surface free energy is 25 mJ / m 2 Above and 35mJ / m 2 Below, and the ratio of the dispersed component in the above-mentioned surface free energy is 95% or more. (4)

[0238] The die-bonding sheet according to any one of (1) to (3) above, wherein the contact angle with water is 90° or more, and the contact angle with diiodomethane is 50° or more. (5)

[0240] The die-bonding sheet according to any one of (1) to (4) above, comprising at least one of a thermosetting resin and a thermoplastic resin. (6)

[0242] The die-bonding sheet according to the above (5), wherein the thermosetting resin includes at least one of an epoxy resin and a phenol resin. (7)

[0244] The die-bonding sheet according to (5) or (6) above, wherein the thermoplastic resin includes an acrylic resin. (8)

[0246] The die-bonding sheet according to any one of (1) to (7) above, comprising a thermosetting resin and a thermoplastic resin. (9)

[0248] The die-bonding sheet according to any one of (1) to (8) above, comprising a thermosetting resin, a thermoplastic resin, and a filler. (10)

[0250] The die-bonding sheet according to the above (9), wherein the content of the thermoplastic resin is 5 mass % or more and 50 mass % or less relative to the total mass of the organic components excluding the filler. (11)

[0252] The die-bonding sheet according to (9) or (10) above, wherein the content of the filler is 30% by mass or more and 70% by mass or less relative to the total mass of the die-bonding sheet. (12)

[0254] The die-bonding sheet according to any one of (1) to (11) above, comprising a thermosetting resin, wherein the content of the thermosetting resin is 5 mass % or more and 60 mass % or less relative to the total mass of the die-bonding sheet. (13)

[0256] The die-bonding sheet according to any one of (1) to (12) is used by bonding to the surface of a semiconductor chip subjected to a surface coating treatment with a polyimide resin. (14)

[0258] A dicing die-bonding film comprising the die-bonding sheet according to any one of (1) to (13) above and a dicing tape bonded to the die-bonding sheet. (15)

[0260] The dicing die-bonding film according to the above (14), wherein the dicing tape comprises a base material layer and a pressure-sensitive adhesive layer superimposed on the base material layer,

[0261] The adhesive layer is bonded to the dicing tape.

[0262] The die-bonding sheet and the dicing die-bonding film of the present embodiment are as exemplified above, but the present invention is not limited to the die-bonding sheet and the dicing die-bonding film exemplified above.

[0263] That is, various forms used in general die-bonding sheets and dicing die-bonding films can be adopted within a range that does not impair the effects of the present invention.

[0264] [Example]

[0265] Next, the present invention will be described in more detail using experimental examples, but the present invention is not limited to these.

[0266] The die-bonding sheet was manufactured as follows: Furthermore, the die-bonding sheet was bonded to a dicing tape to manufacture a dicing die-bonding film.

[0267] <Production of Die Bonding Sheet>

[0268] The raw materials having the formulation shown in Table 1 were added to methyl ethyl ketone and mixed to obtain a die-bonding sheet composition having a solid content concentration of 40% by mass. The details of each raw material are shown below.

[0269] ·Silica filler: Made by Admatechs Co. Ltd., raw material name "SO-E2"

[0270] ·Acrylic resin: Made by Nagase ChemteX Corporation

[0271] Raw material name: "TEISAN RESIN SG-280EK23" (containing -COOH group)

[0272] Raw material name: "TEISAN RESIN SG-708-6" (containing -COOH and -OH groups)

[0273] Raw material name: "TEISAN RESIN SG-P3" (containing glycidyl)

[0274] · Epoxy resin: Made by Nippon Kayaku Co., Ltd., raw material name "EPPN-501HY" (triphenolmethane type)

[0275] DIC Corporation, raw material name "HP-7200L" (dicyclopentadiene type)

[0276] DIC Corporation, raw material name "N-665-EXP-S" (cresol novolac type)

[0277] · Phenolic resin: Made by Meiwa Chemicals Co., Ltd., raw material name "H-4" (phenol novolac type)

[0278] ·Curing catalyst: Made by Hokuko Chemical Co., Ltd., raw material name "TPP-K"

[0279] Next, the die bonding sheet composition was applied on one side of the release sheet (the side of the PET sheet with a thickness of 50 μm that was treated with silicone) using an applicator. The coating was performed in such a way that the thickness after drying became 40 μm, and then the die bonding sheet composition was dried at 130° C. for 2 minutes to volatilize the solvent from the die bonding sheet composition. Thus, a die bonding sheet overlapped on the release sheet was obtained.

[0280] <Base material layer of dicing tape>

[0281] Using the products shown below as raw materials, a three-layer laminated base material layer was produced.

[0282] Resin constituting the inner layer (or the base layer constituting the single layer)

[0283] Ingredient name: ULTRATHENE 751

[0284] Ethylene-vinyl acetate copolymer resin (EVA contains 28% by mass of vinyl acetate)

[0285] Made by Tosoh Corporation

[0286] Resin constituting the outer layer

[0287] Raw material name: WINTEC WFX4M

[0288] Metallocene Polypropylene

[0289] Made by Japan Polypropylene Corporation

[0290] (Formation of base material layer)

[0291] The substrate layer was formed using an extrusion T-die molding machine. The extrusion temperature was 190° C. The three-layer laminated substrate layer was co-extruded from a T-die to be integrated. After the integrated substrate layer (laminated body) was fully cured, the substrate layer was rolled up and stored.

[0292] <Adhesive Layer of Dicing Tape>

[0293] (Preparation of Adhesive Layer (Adhesive Composition))

[0294] The following raw materials were mixed to prepare a first resin composition.

[0295] INA (isononyl acrylate) 173 parts by mass

[0296] HEA (hydroxyethyl acrylate) 54.5 parts by mass

[0297] ·AIBN (2,2'-azobisisobutyronitrile) 0.46 parts by mass

[0298] · 372 parts by mass of ethyl acetate

[0299] Next, the first resin composition was placed in a round-bottom separable flask of a polymerization experimental apparatus equipped with a round-bottom separable flask (capacity 1 L), a thermometer, a nitrogen introduction tube, and a stirring blade. The first resin composition was stirred while the liquid temperature of the first resin composition was adjusted to room temperature (23° C.), and the inside of the round-bottom separable flask was replaced with nitrogen for 6 hours.

[0300] Next, nitrogen gas was flowed into the round-bottom separable flask, and the first resin composition was kept at a liquid temperature of 62° C. for 3 hours while stirring the first resin composition. Then, the temperature was further kept at 75° C. for 2 hours to carry out the polymerization reaction of INA, HEA, and AIBN, thereby preparing a second resin composition. Then, the flow of nitrogen gas into the round-bottom separable flask was stopped.

[0301] After the second resin composition was cooled to room temperature, the following raw materials were added to the second resin composition to prepare a third resin composition.

[0302] ·2-Methacryloyloxyethyl isocyanate

[0303] Compounds with polymerizable carbon-carbon double bonds

[0304] Raw material name: "Karenz MOI", manufactured by Showa Denko K.K.) 52.5 parts by mass

[0305] · Dibutyltin dilaurate IV (manufactured by Wako Pure Chemical Industries, Ltd.) 0.26 parts by mass

[0306] The obtained third resin composition was stirred at 50° C. for 24 hours in an air atmosphere.

[0307] Finally, the following raw materials were added to 100 parts by mass of the polymer solid content of the third resin composition.

[0308] Isocyanate compound (raw material name: "CORONATE L", manufactured by Tosoh Corporation) 0.75 parts by mass

[0309] Photopolymerization initiator (raw material name: "Omnirad 127", manufactured by IGM Resins Co., Ltd.) 2 parts by mass

[0310] Then, the third resin composition was diluted with ethyl acetate so as to have a solid content concentration of 20% by mass to prepare a binder composition.

[0311] <Production of cutting tape>

[0312] The adhesive composition was applied to one surface of the base layer using an applicator to a thickness of 10 μm. The base layer after the adhesive composition was applied was heated and dried at 110° C. for 3 minutes to form an adhesive layer, thereby producing a dicing tape.

[0313] <Manufacturing of Dicing Die-Bonding Film>

[0314] (Attachment of die bonding sheet to dicing tape)

[0315] The adhesive layer of the dicing tape is bonded to the die-bonding sheet (the side on which the release sheet is not laminated). Then, the release sheet is peeled off from the die-bonding sheet to prepare a dicing die-bonding film having the die-bonding sheet.

[0316] In the above-mentioned operation, the die-bonding sheets and dicing die-bonding films of Examples and Comparative Examples were respectively manufactured by the above-mentioned method. The details of each die-bonding sheet are shown in Table 1.

[0317] [Table 1]

[0318] The following is the solid content conversion value

[0319]

[0320] (Peeling force of die-bonding sheet from polyimide resin surface)

[0321] For each of the dicing die-bonding films of the example and the comparative example, the peeling force of one surface (the surface on the side to which the release sheet was attached) of the die-bonding sheet was measured.

[0322] In detail, first, remove the peeling sheet attached to the chip bonding sheet, and bond the exposed surface of the chip bonding sheet (the surface to be bonded to the semiconductor chip later) to one surface of the polyimide resin film (Kapton100H: manufactured by DU PONT-TORAY CO., LTD.). Bonding is carried out under the conditions of 60°C and 10 mm / sec. Then, a backing tape (trade name: BT-315 (manufactured by Nitto Denko Corporation)) is bonded to the other side of the polyimide resin film (the side opposite to the side bonded to the DAF) at 23°C using a hand roller. Next, cut into 50 mm widths to prepare a sample for measurement, and measure the peeling force at an atmosphere of 23°C, a peeling angle of 180°, and a peeling speed of 300 mm / min. It should be noted that an Autograph (manufactured by SHIMADZU) was used as a measuring device.

[0323] (Method for measuring surface free energy of die bond sheet)

[0324] The surface free energy of one surface (the surface on the side to which the release sheet was attached) of each of the dicing die-bonding films of Examples and Comparative Examples was measured.

[0325] The contact angles of water and diiodomethane were measured respectively, and the average of 5 measured values ​​was adopted. In addition, FAMAS (manufactured by KYOWA Corporation) was used as a measuring device, and 1 mL of liquid was dropped on the surface and the contact angle was measured within 5 seconds.

[0326] The dispersed component and the polar component are calculated from each measured value of the contact angle, and the surface free energy is obtained from the sum. The method for calculating the surface free energy is as described above.

[0327] (Fabrication of Warped Wafers for Performance Evaluation)

[0328] In order to use a wafer that is prone to floating for evaluation in the “floating evaluation from a chip” described later, a “warped wafer” was prepared as follows.

[0329] First, the following (a) to (f) were dissolved in methyl ethyl ketone to obtain a warpage adjusting composition having a solid content concentration of 20% by mass.

[0330] (a) Acrylic resin (manufactured by Nagase ChemteX Corporation, raw material name: "SG-70L"): 5 parts by mass

[0331] (b) Epoxy resin (Mitsubishi Chemical Corporation, raw material name "JER828"): 5 parts by mass

[0332] (c) Phenolic resin (manufactured by Meiwa Chemicals Co., Ltd., raw material name "LDR8210"): 14 parts by mass

[0333] (d) Epoxy resin (manufactured by Mitsubishi Chemical Corporation, raw material name "MEH-8005"): 2 parts by mass

[0334] (e) Spherical silica (manufactured by Admatechs Co. Ltd., raw material name: "SO-25R"): 53 parts by mass

[0335] (f) Phosphorus-based catalyst (TPP-K): 1 part by mass

[0336] Next, the warp adjustment composition was applied to one surface of the release sheet (the silicone-treated surface of the 50 μm thick PET sheet) using an applicator to a thickness of 25 μm. A drying treatment was performed at 130° C. for 2 minutes to volatilize the solvent from the warp adjustment composition. Thus, a warp adjustment sheet having a warp adjustment layer superimposed on the release sheet was prepared.

[0337] Next, the bare wafer is attached to the warp adjustment layer of the warp adjustment sheet (on the opposite side to the peeling sheet). For attachment, a laminator (MCK, model MRK-600) is used at 60°C, 0.1MPa, and 10mm / s. After attachment, it is placed in an oven and heated at 175°C for 1 hour to cure the warp adjustment layer. As a result, the warp adjustment layer shrinks, thereby obtaining a warped bare wafer.

[0338] After shrinking the warp adjustment layer as described above, a wafer processing tape (manufactured by Nitto Denko Corporation, trade name "V-12SR2") is attached to the exposed side of the warped bare wafer (the side to which the warp adjustment layer is not attached). Then, a dicing ring is fixed to the warped bare wafer by means of the wafer processing tape. Then, the warp adjustment layer is removed from the warped bare wafer.

[0339] Using a dicing apparatus (manufactured by DISCO, Model 6361), grooves having a depth of 100 μm were formed in a grid pattern (width 20 μm) over the entire surface of one surface (the surface from which the warp adjusting layer was removed) of the warped bare wafer.

[0340] A back grinding tape is attached to the one surface of the warped bare wafer, and the wafer processing tape is removed from the other surface of the warped bare wafer.

[0341] The warped bare wafer was ground from the other surface using a back grinder (manufactured by DISCO, model DGP8760) so that the thickness of the warped bare wafer became 55 μm (0.055 mm), thereby obtaining a “warped wafer”.

[0342] (Evaluation of Die-bonding Sheet Lifting Performance from Semiconductor Chip)

[0343] After the expansion process, a semiconductor chip with a die-bonding pad is obtained from the "warped wafer". After the semiconductor chip with the die-bonding pad is picked up from the dicing tape, the die is bonded to the lead frame through the die-bonding pad.

[0344] Next, another semiconductor chip with a die-bonding sheet obtained through the above-mentioned expansion step is picked up from the dicing tape, and the semiconductor chip on the lead frame is die-bonded by means of the die-bonding sheet. In other words, the semiconductor chips with the die-bonding sheets are stacked.

[0345] When stacking semiconductor chips (squares when viewed from above) with chip bonding sheets, chip bonding is performed in a manner that the position of the upper semiconductor chip is offset and not completely overlapped when viewed from above. The position offset direction is the extension direction of any side of the semiconductor chip, and the position offset length is set to 200μm. Then, the same stacked chip bonding is repeated 5 times. It should be noted that in each chip bonding, the direction of the above-mentioned position offset (position offset length 200μm) is the same direction. In addition, each chip bonding is performed under the conditions of 100°C, a pressure of 0.2MPa, and a pressing time of 2 seconds.

[0346] In the chip bonding process, all semiconductor chips when the semiconductor chips are stacked at 7 levels (at the time of the 7th chip bonding) are observed, and the case where even one chip bonding piece does not float from the semiconductor chip is evaluated as having good floating suppression performance (0). On the other hand, if only one chip bonding piece floats from the semiconductor chip, it is evaluated as having poor floating suppression performance (×).

[0347] The results of contact angle measurement, calculated surface free energy values, and performance evaluation (lift-off suppression performance) of the die-bonding sheets of each example and each comparative example are shown in Table 1, respectively.

[0348] From the above evaluation results, it can be understood that the dicing die-bonding film including the die-bonding sheet of the example can suppress the floating of the semiconductor chip when the semiconductor chips are stacked a plurality of times, as compared with the dicing die-bonding film of the comparative example.

[0349] The die-bonding sheet of the example had a peeling force of 0.1 N / 50 mm or more on the surface bonded to the adherend (with respect to the polyimide resin surface), and a surface free energy of 35 mJ / m 2 the following.

[0350] By using the die-bonding sheet (dicing die-bonding film) of the embodiment having such physical properties in the manufacture of a semiconductor integrated circuit, a so-called NAND type flash memory or the like can be manufactured efficiently.

[0351] Industrial Applicability

[0352] The die-bonding sheet and dicing die-bonding film of the present invention are suitably used as auxiliary tools in manufacturing semiconductor integrated circuits, for example.

Claims

1. A die bonding sheet comprising a thermosetting resin, a thermoplastic resin and a silica filler, The thermosetting resin includes a trisphenol methane type or cresol novolac type epoxy resin and a novolac type phenolic resin, and the thermoplastic resin includes an acrylic resin having a structural unit of a (meth)acrylic acid alkyl ester and a structural unit of a carboxyl group-containing monomer in the molecule. The surface free energy of the die bonding sheet is 35 mJ / m 2 Hereinafter, the proportion of the dispersed component in the surface free energy is 95% or more, The die-bonding sheet has a peeling force of 0.1 N / 50 mm or more with respect to a polyimide resin surface. 2 . The die-bonding sheet according to claim 1 , which has a contact angle with water of 90° or more and a contact angle with diiodomethane of 50° or more. 3 . A dicing die-bonding film comprising: the die-bonding sheet according to claim 1 or 2 , and a dicing tape bonded to the die-bonding sheet.

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