Dicing tape and dicing die-bonding film

Abstract

To provide a dicing tape or the like capable of making it compatible that a semiconductor chip can be satisfactorily manufactured by making a semiconductor wafer into small pieces, and that satisfactory pickup properties can be exhibited.SOLUTION: The dicing tape includes a base material layer and an adhesive layer laminated on one surface of the base material layer, wherein the adhesive layer contains a (meth) acrylic polymer containing an acrylate-methacrylate copolymer, and the ratio of the acrylate-methacrylate copolymer in the (meth) acrylic polymer is 50% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dicing tape used when manufacturing, for example, a semiconductor device, and a dicing die bond film provided with the dicing tape. [Background technology]

[0002] Conventionally, dicing die bond films used in the manufacture of semiconductor devices and the like have been known. This type of dicing die bond film includes, for example, a dicing tape and a die bond sheet laminated on the dicing tape and adhered to a semiconductor wafer. The dicing tape has a base layer and a pressure-sensitive adhesive layer in contact with the die bond sheet. This type of dicing die bond film is used in the manufacture of semiconductor devices, for example, as follows.

[0003] A method for manufacturing a semiconductor device generally includes a front-end process in which a circuit surface is formed on one side of a disk-shaped bare wafer using highly integrated electronic circuits, and a back-end process in which semiconductor chips are cut out from the semiconductor wafer on which the circuit surface has been formed and assembled.

[0004] For example, the post-processing includes a mounting process in which the surface of the semiconductor wafer opposite the circuit surface is attached to a die bond sheet and the semiconductor wafer is fixed to a dicing tape via the die bond sheet, a dicing process in which the semiconductor wafer is diced together with the die bond sheet to obtain a plurality of semiconductor chips (dies), a pick-up process in which the die bond sheet is peeled off from the adhesive layer to remove the semiconductor chips with the die bond sheet pieces attached, a die bond process in which the semiconductor chips are attached to an adherend via the die bond sheet pieces, and a curing process in which the die bond sheet attached to the adherend is thermally cured. A semiconductor device is manufactured through, for example, these processes.

[0005] In the above-mentioned post-processing, for example, in order to dicing the semiconductor wafer into semiconductor chips (dies), the dicing process may include a stealth dicing process in which a weak portion is formed inside the semiconductor wafer using laser light, a mounting process in which the semiconductor wafer is fixed to a dicing tape as described above, and an expanding process in which the dicing tape is stretched in the radial direction of the semiconductor wafer, the semiconductor wafer in which the weak portion has been formed is cut together with the die bond sheet to diced into small pieces, and the spacing between adjacent diced semiconductor chips (dies) is widened. On the other hand, instead of the stealth dicing process described above, a blade dicing process may be carried out as the dicing process, in which the semiconductor wafer fixed to the dicing tape in the mounting process is cut into small pieces using a dicing blade or the like.

[0006] In the above-described method for manufacturing a semiconductor device, various problems can arise. For example, the adhesive layer of the dicing tape needs to have a relatively high adhesive strength while fixing the semiconductor wafer, but needs to have a relatively low adhesive strength when picking up the semiconductor chip, but these contradictory properties may not be exhibited well. In contrast to this, a semiconductor processing tape is known that can be used for fixing not only semiconductor wafers but also memory packages and the like, and that can exhibit the above-mentioned contradictory properties (for example, Patent Document 1).

[0007] The semiconductor processing tape described in Patent Document 1 has an ultraviolet-curable adhesive layer. Such an ultraviolet-curable adhesive layer has a viscosity of 7.0 × 10 at 25°C before curing. 4 It has a shear storage modulus of 2.0 x 10 Pa or more at 25°C after curing. 7 The adhesive has a tensile storage modulus of 10 Pa or more, a water contact angle of 115° or less before curing, and contains 10 parts by mass or more of a filler per 100 parts by mass of the ultraviolet-curable pressure-sensitive adhesive layer. Specifically, the above-mentioned ultraviolet-curable pressure-sensitive adhesive layer contains a (meth)acrylic polymer of a specific monomer composition polymerized with a specific polymerization initiator, and can have a relatively high adhesive strength before curing, but a low adhesive strength after curing. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent Publication No. 2021-061347 Summary of the Invention [Problem to be solved by the invention]

[0009] However, even in the case of a semiconductor processing tape as described in Patent Document 1, if the ultraviolet-curable adhesive layer simply contains the above-mentioned (meth)acrylic polymer of a specific monomer composition polymerized with a specific polymerization initiator, further problems may arise in the method for manufacturing a semiconductor device.

[0010] For example, when a semiconductor wafer is diced into small pieces to produce a large number of semiconductor chips, the following problems may arise. Specifically, when the above-mentioned blade dicing process is performed, a problem may occur in which a semiconductor chip produced by cutting the semiconductor wafer with a dicing blade or the like is chipped. More specifically, a chipping phenomenon may occur in which a chip occurs in a portion near the cut surface of the semiconductor chip. Possible causes of chipping include a portion of the adhesive layer adhering to the dicing blade or the like, or the force applied when the semiconductor wafer is diced being transmitted to the adhesive layer, causing the adhesive layer and the semiconductor wafer to vibrate relatively greatly. Furthermore, for example, when a semiconductor wafer that has undergone the above-mentioned stealth dicing process is cut, a problem may arise in that the semiconductor wafer is not necessarily cut well. Such poor cuttability is thought to be related to the physical properties of the pressure-sensitive adhesive layer.

[0011] Furthermore, in the above-mentioned pick-up process, smooth peeling does not occur between the die bond sheet and the adhesive layer, and the semiconductor chip may not necessarily be picked up properly, i.e., good pick-up properties may not be exhibited. Therefore, there is a demand for a dicing tape that can satisfactorily produce semiconductor chips by dicing semiconductor wafers and that can also exhibit good pick-up properties.

[0012] Therefore, an object of the present invention is to provide a dicing tape and a dicing die bond film that can effectively produce semiconductor chips by dicing semiconductor wafers and that can exhibit good pick-up properties. [Means for solving the problem]

[0013] In order to solve the above problems, the dicing tape according to the present invention comprises: A substrate layer and a pressure-sensitive adhesive layer superimposed on one surface of the substrate layer, the pressure-sensitive adhesive layer contains a (meth)acrylic polymer containing an acrylate-methacrylate copolymer, The proportion of the acrylate-methacrylate copolymer in the (meth)acrylic polymer is 50% or more.

[0014] The dicing die bond film according to the present invention is The device includes the above dicing tape and a die bond sheet superimposed on the dicing tape. [Effects of the Invention]

[0015] The dicing tape and dicing die bond film according to the present invention can satisfactorily perform the production of semiconductor chips by dicing a semiconductor wafer, and can also exhibit good pick-up properties. [Brief explanation of the drawings]

[0016] [Figure 1]FIG. 2 is a cross-sectional view of the dicing die bond film of the present embodiment cut in the thickness direction. [Figure 2] FIG. 2 is a cross-sectional view of the dicing tape of the present embodiment cut in the thickness direction. [Figure 3A] 1A and 1B are cross-sectional views schematically illustrating a stealth dicing step in a method for manufacturing a semiconductor device. [Figure 3B] 1A and 1B are cross-sectional views schematically illustrating a stealth dicing step in a method for manufacturing a semiconductor device. [Figure 3C] 1A and 1B are cross-sectional views schematically illustrating a stealth dicing step in a method for manufacturing a semiconductor device. [Figure 3D] 1A to 1C are cross-sectional views schematically illustrating a back grinding step in the method for manufacturing a semiconductor device. [Figure 4A] 1A to 1C are cross-sectional views schematically illustrating a mounting step in a method for manufacturing a semiconductor device. [Figure 4B] 1A to 1C are cross-sectional views schematically illustrating a mounting step in a method for manufacturing a semiconductor device. [Figure 5A] 10A and 10B are cross-sectional views schematically illustrating an expanding step at a low temperature in the method for manufacturing a semiconductor device. [Figure 5B] 10A and 10B are cross-sectional views schematically illustrating an expanding step at a low temperature in the method for manufacturing a semiconductor device. [Figure 5C] 10A and 10B are cross-sectional views schematically illustrating an expanding step at a low temperature in the method for manufacturing a semiconductor device. [Figure 6A] 1A to 1C are cross-sectional views schematically illustrating an expanding step at room temperature in a method for manufacturing a semiconductor device. [Figure 6B] 1A to 1C are cross-sectional views schematically illustrating an expanding step at room temperature in a method for manufacturing a semiconductor device. [Figure 7] FIG. 10 is a schematic cross-sectional view showing an example of how a semiconductor wafer and a die bond sheet are diced into small pieces. [Figure 8] 1A to 1C are cross-sectional views schematically illustrating a pickup step in a method for manufacturing a semiconductor device. [Figure 9] 5A and 5B are cross-sectional views schematically illustrating a state after a die bonding step and a wire bonding step in the method for manufacturing a semiconductor device. [Figure 10] 5A to 5C are cross-sectional views schematically illustrating a sealing step in the method for manufacturing a semiconductor device. [Figure 11] Photographs showing examples of images used to evaluate chipping suppression performance. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of a dicing tape according to the present invention and a dicing die bond film including the dicing tape will be described with reference to the drawings.

[0018] As shown in FIG. 1, the dicing die bond film 1 of this embodiment includes a dicing tape 20 and a die bond sheet 10 laminated on an adhesive layer 22 (described later) of the dicing tape 20 and adhered to a semiconductor wafer. It should be noted that the figures in the drawings are schematic diagrams and the aspect ratios are not necessarily the same as those of the actual product.

[0019] In the dicing die bond film 1 of this embodiment, when used, the pressure-sensitive adhesive layer 22 is cured by irradiation with active energy rays (e.g., ultraviolet rays). More specifically, in a state in which the die bond sheet 10 having a semiconductor wafer bonded to one surface and the pressure-sensitive adhesive layer 22 attached to the other surface of the die bond sheet 10 are laminated together, ultraviolet rays or the like are irradiated onto at least the pressure-sensitive adhesive layer 22. For example, ultraviolet rays or the like are irradiated from the side where the base layer 21 is disposed, and the ultraviolet rays or the like reach the pressure-sensitive adhesive layer 22 after passing through the base layer 21. The pressure-sensitive adhesive layer 22 is cured by irradiation with ultraviolet rays or the like. Since the adhesive layer 22 hardens after irradiation, the adhesive strength of the adhesive layer 22 can be reduced, and therefore, after irradiation, the die bond sheet 10 (with the semiconductor chip adhered thereto) can be relatively easily peeled off from the adhesive layer 22. In the manufacture of a semiconductor device, the die bond sheet 10 is adhered to an adherend such as a circuit board or a semiconductor chip.

[0020] <Dicing tape for dicing die bond film> The dicing tape 20 is usually a long sheet and can be stored in a rolled state until use. The dicing die bond film 1 of this embodiment is stretched on an annular frame having an inner diameter slightly larger than the silicon wafer to be cut, and then cut for use.

[0021] 2, the dicing tape 20 includes a base layer 21 and an adhesive layer 22 overlaid on the base layer 21. The adhesive layer 22 of the dicing tape 20 is, for example, a pressure-sensitive adhesive layer.

[0022] As described below, the dicing die bond film 1 of this embodiment is provided with a dicing tape 20 that improves the breakability of the semiconductor wafer, and therefore can exhibit good breakability even if the breakability of the die bond sheet 10 is not very good.

[0023] [Adhesive layer of dicing tape] The pressure-sensitive adhesive layer 22 contains a (meth)acrylic polymer. The (meth)acrylic polymer is a polymer obtained by polymerization of at least one of an acrylate monomer (acrylic acid ester) and a methacrylate monomer (methacrylic acid ester), in which the total amount of the acrylate monomer and the methacrylate monomer in the molecule accounts for 80 mol % or more. The (meth)acrylic polymer includes at least an acrylate-methacrylate copolymer in which both an acrylate monomer and a methacrylate monomer are polymerized. Therefore, the (meth)acrylic polymer may further include a homopolymer of an acrylate monomer or a homopolymer of a methacrylate monomer. Furthermore, the proportion of the acrylate-methacrylate copolymer in the (meth)acrylic polymer is 50% or more, which allows for good semiconductor chip production by dicing the semiconductor wafer and good pickup properties.

[0024] In this specification, the term "(meth)acrylic" refers to at least one of methacrylic and acrylic. Similarly, the term "(meth)acrylate" refers to at least one of methacrylate (methacrylic acid ester) and acrylate (acrylic acid ester). On the other hand, when written as "acrylic" or "methacrylic," it means an "acrylic structure" and a "methacrylic structure," respectively, which have different molecular structures. The same applies to the notations "(meth)acrylate" and "(meth)acrylate."

[0025] The proportion of the acrylate-methacrylate copolymer is preferably 55% or more, more preferably 60% or more, even more preferably 65% ​​or more, and even more preferably 70% or more. A larger proportion of this type can more effectively achieve both the successful production of semiconductor chips by dicing semiconductor wafers and the satisfactory pickup properties. This proportion may be 95% or less.

[0026] The proportion of the acrylate-methacrylate copolymer can be increased, for example, by employing an azo polymerization initiator as the polymerization initiator when polymerizing such a copolymer. The proportion of the above acrylate-methacrylate copolymer can be increased, for example, by setting the mass ratio of the acrylate monomer to the methacrylate monomer to 2 or more and 4 or less (more preferably 2.5 or more and 3.5 or less) during the polymerization reaction of a monomer mixture containing both an acrylate monomer and a methacrylate monomer. The proportion of the above acrylate-methacrylate copolymer can be increased, for example, by adjusting the mass ratio of the azo polymerization initiator to the total amount of monomers to 0.2 or more and 0.6 or less during the polymerization reaction of a monomer mixture containing both acrylate monomers and methacrylate monomers. The ratio of the acrylate-methacrylate copolymer can be adjusted appropriately, for example, by changing the type of reaction solvent used in the polymerization reaction to obtain the polymer. Ethyl acetate is preferred as the reaction solvent.

[0027] Incidentally, even if a polymerization initiator is simply added to a monomer mixture containing both an acrylate monomer and a methacrylate monomer to allow the polymerization reaction to proceed, the proportion of the above-mentioned acrylate-methacrylate copolymer in the (meth)acrylic polymer after the polymerization reaction does not necessarily become high. For example, when an organic peroxide polymerization initiator is used as the polymerization initiator instead of an azo polymerization initiator, the polymerization reaction between acrylate monomers and the polymerization reaction between methacrylate monomers are more likely to proceed, and therefore the proportion of the acrylate-methacrylate copolymer may be lowered. For example, if the amount of either the acrylate monomer or the methacrylate monomer is extremely high or low, the polymerization reaction between the acrylate monomers and the polymerization reaction between the methacrylate monomers will be more likely to proceed, and the proportion of the acrylate-methacrylate copolymer may become low. For example, when the ratio of the amount of polymerization initiator to the total amount of acrylate monomers and methacrylate monomers is significantly small, the polymerization reaction between acrylate monomers and the polymerization reaction between methacrylate monomers tend to proceed more easily, and the proportion of the above-mentioned acrylate-methacrylate copolymer may become low.

[0028] The proportion of the acrylate-methacrylate copolymer is measured by the following method. Specifically, the proportion of the acrylate-methacrylate copolymer is measured by high performance liquid chromatography (HPLC) under the following measurement conditions. The above-mentioned solution of (meth)acrylic polymer containing acrylate-methacrylate copolymer for measurement is weighed in a screw tube, and tetrahydrofuran (THF) is added so that the solid content becomes 0.3 [mass / vol]%. After adding THF, the solution is shaken for 12 hours or more. After shaking, the solution is filtered through a membrane filter, and the filtrate is measured by HPLC. HPLC device: For example, Shimadzu Corporation "LC2060" Detector: For example, Waters "ELS2424" Column: Zorbax C18 (diameter 4.6 mm x 150 mm 5 μm) Eluent composition: Acetonitrile / THF gradient conditions with trifluoroacetic acid added Flow rate: 1.0mL / min. Detector: ELSD Gain: 5 Tube temperature: 90℃ Column temperature: 50℃ Injection volume: 10μL The heights of the following peaks A, B, and C are determined from the measurement chart, and the proportion of the above acrylate-methacrylate copolymer is calculated from the ratio of the peak height of C to the total value of the peak heights of A, B, and C. A: Peak height of the homopolymer of acrylic monomer B: Peak height of homopolymer of methacrylic monomer C: Peak height of acrylate-methacrylate copolymer

[0029] The acrylate-methacrylate copolymer preferably contains a molecule having a residue derived from an azo polymerization initiator at at least one end of the main chain, i.e., the acrylate-methacrylate copolymer is preferably polymerized with an azo polymerization initiator.

[0030] As described above, the (meth)acrylic polymer has at least one of an acrylate monomer unit and a methacrylate monomer unit in the molecule. Therefore, the (meth)acrylic polymer may include other polymers in addition to the acrylate-methacrylate copolymer, such as a homopolymer of an acrylic monomer or a homopolymer of a methacrylic monomer.

[0031] In this embodiment, the pressure-sensitive adhesive layer 22 contains, for example, a (meth)acrylic polymer containing the above-mentioned acrylate-methacrylate copolymer, an isocyanate compound, and a polymerization initiator.

[0032] The acrylate-methacrylate copolymer preferably contains an alkyl (meth)acrylate unit and a crosslinkable group-containing (meth)acrylate unit as monomer units in the molecule. The alkyl (meth)acrylate unit is a non-crosslinkable (meth)acrylate unit. The crosslinkable group-containing (meth)acrylate unit includes, for example, a hydroxyalkyl (meth)acrylate unit (described in detail below) or a polymerizable (meth)acrylate unit having a polymerizable unsaturated double bond (radical polymerizable carbon-carbon double bond) in the side chain. The term "unit" refers to a structure derived from each monomer after polymerization of a monomer (for example, 2-ethylhexyl acrylate, hydroxyethyl acrylate, etc.) when polymerizing an acrylate-methacrylate copolymer. The same applies hereinafter.

[0033] As described above, the acrylate-methacrylate copolymer may have at least an alkyl (meth)acrylate unit and a crosslinkable group-containing (meth)acrylate unit as monomer units in the molecule. The monomer units are units that constitute the main chain of the acrylate-methacrylate copolymer. In other words, the monomer units are derived from the monomers used to polymerize the acrylate-methacrylate copolymer. Each side chain in the acrylate-methacrylate copolymer is contained in each monomer unit that constitutes the main chain.

[0034] The alkyl (meth)acrylate unit is derived from an alkyl (meth)acrylate monomer. In other words, the molecular structure obtained after the alkyl (meth)acrylate monomer is polymerized is an alkyl (meth)acrylate unit. The term "alkyl" refers to the hydrocarbon moiety ester-bonded to (meth)acrylic acid.

[0035] The alkyl portion (hydrocarbon) in the alkyl (meth)acrylate unit may be a saturated hydrocarbon or an unsaturated hydrocarbon. The alkyl portion (hydrocarbon) in the alkyl (meth)acrylate unit may be a straight-chain hydrocarbon, a branched-chain hydrocarbon, or may contain a cyclic structure. The alkyl portion (hydrocarbon) in the alkyl(meth)acrylate unit may have 2 or more and 22 or less carbon atoms.

[0036] The acrylate-methacrylate copolymer more preferably contains, as the alkyl(meth)acrylate unit, a saturated alkyl(meth)acrylate unit in which the alkyl moiety is a saturated hydrocarbon having 4 to 18 carbon atoms.

[0037] In the acrylate-methacrylate copolymer, the proportion (molar equivalent) of alkyl(meth)acrylate units is preferably the highest among all monomer units in the molecule. For example, alkyl(meth)acrylate units having an alkyl moiety with 4 or more carbon atoms (preferably 8 or more carbon atoms) may account for 50% to 90% of all monomer units in molar equivalent.

[0038] The saturated alkyl (meth)acrylate unit preferably does not contain any polar groups such as a benzene ring, an ether bond (-CH2-O-CH2-), an -OH group, or a -COOH group in the molecule. In the saturated alkyl (meth)acrylate unit, the alkyl portion does not contain atoms other than C and H and may be a saturated linear hydrocarbon or a saturated branched hydrocarbon composed of 4 to 10 carbon atoms.

[0039] The acrylate-methacrylate copolymer preferably contains, as the alkyl (meth)acrylate unit, at least one of a saturated branched alkyl (meth)acrylate unit having an alkyl moiety with 7 to 11 carbon atoms, and a saturated linear alkyl (meth)acrylate unit having an alkyl moiety with 2 to 7 carbon atoms.

[0040] The structure of the alkyl portion (hydrocarbon portion) of the saturated branched alkyl (meth)acrylate unit may be a saturated branched alkyl structure, and may be an iso structure, a sec structure, a neo structure, or a tert structure. Specific examples of saturated branched alkyl (meth)acrylate units include isohexyl (meth)acrylate, isoheptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate units. Among these, 2-ethylhexyl (meth)acrylate units are preferred.

[0041] The structure of the alkyl portion (hydrocarbon portion) of the saturated linear alkyl (meth)acrylate unit may be any structure as long as it is a saturated linear alkyl structure. Specific examples of saturated linear alkyl (meth)acrylate units include n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate units.

[0042] The acrylate-methacrylate copolymer may contain one type of alkyl (meth)acrylate unit alone, or may contain two or more types of alkyl (meth)acrylate units.

[0043] The crosslinkable group-containing (meth)acrylate unit has a hydroxy group capable of forming a urethane bond through a urethanization reaction or a polymerizable group capable of polymerizing through a radical reaction. More specifically, the crosslinkable group-containing (meth)acrylate unit has either an unreacted hydroxy group or a radically polymerizable carbon-carbon double bond as a polymerizable group. For example, some of the crosslinkable group-containing (meth)acrylate units have an unreacted hydroxy group, and the other part (all others) have no hydroxy group but have a radically polymerizable carbon-carbon double bond.

[0044] The above acrylate-methacrylate copolymer preferably has, as the crosslinkable group-containing (meth)acrylate unit, a hydroxyalkyl (meth)acrylate unit in which a hydroxy group is bonded to a hydrocarbon moiety having from 2 to 7 carbon atoms. In other words, the above acrylate-methacrylate copolymer preferably has, in the molecule, at least one of a hydroxyalkyl acrylate unit having from 2 to 7 carbon atoms in the alkyl moiety, and a hydroxyalkyl methacrylate unit having from 2 to 7 carbon atoms in the alkyl moiety. When the pressure-sensitive adhesive layer 22 contains an isocyanate compound, the isocyanate group of the isocyanate compound and the hydroxy group of the hydroxyalkyl (meth)acrylate unit can easily react with each other. By allowing the (meth)acrylic polymer having a hydroxyalkyl (meth)acrylate unit and the isocyanate compound to coexist in the pressure-sensitive adhesive layer 22, the pressure-sensitive adhesive layer 22 can be appropriately cured. This allows the acrylate-methacrylate copolymer to be sufficiently gelled. This allows the pressure-sensitive adhesive layer 22 to maintain its shape while exhibiting adhesive performance.

[0045] The hydroxyalkyl (meth)acrylate unit is preferably a hydroxy C2-C6 alkyl (meth)acrylate unit in which an OH group is bonded to a hydrocarbon moiety having from 2 to 6 carbon atoms, and more preferably a hydroxy C2-C4 alkyl (meth)acrylate unit in which an OH group is bonded to a hydrocarbon moiety having from 2 to 4 carbon atoms. The term "C2-C4 alkyl" refers to the number of carbon atoms in the hydrocarbon moiety ester-bonded to the (meth)acrylic acid. In other words, a hydroxy C2-C4 alkyl (meth)acrylic monomer refers to a monomer in which (meth)acrylic acid is ester-bonded to an alcohol (usually a dihydric alcohol) having from 2 to 4 carbon atoms. The same applies hereinafter in this specification. The hydrocarbon portion of the C2-C6 alkyl is usually a saturated hydrocarbon. For example, the hydrocarbon portion of the C2-C6 alkyl is a linear saturated hydrocarbon or a branched saturated hydrocarbon. It is preferable that the hydrocarbon portion of the C2-C6 alkyl does not contain a polar group containing oxygen (O), nitrogen (N), or the like.

[0046] Examples of the hydroxy C2-C6 alkyl (meth)acrylate unit include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate such as hydroxy n-butyl (meth)acrylate or hydroxy isobutyl (meth)acrylate, and hydroxyhexyl (meth)acrylate units. The hydroxy group (-OH group) may be bonded to a terminal carbon (C) of the hydrocarbon moiety, or to a carbon (C) other than the terminal of the hydrocarbon moiety.

[0047] Preferably, the acrylate-methacrylate copolymer has at least one of saturated branched alkyl acrylate units having 7 to 11 carbon atoms in the alkyl portion and saturated linear alkyl acrylate units having 2 to 7 carbon atoms in the alkyl portion, and a hydroxy C2-C4 alkyl methacrylate unit in the molecule.

[0048] The above acrylate-methacrylate copolymer preferably contains, as the crosslinkable group-containing (meth)acrylate unit, a polymerizable (meth)acrylate unit having a polymerizable unsaturated double bond (radical polymerizable carbon-carbon double bond) in the side chain.

[0049] Specifically, the polymerizable (meth)acrylate unit has a molecular structure in which an isocyanate group of an isocyanate group-containing (meth)acrylic monomer is urethane-bonded to a hydroxy group in the above-mentioned hydroxyalkyl (meth)acrylate unit.

[0050] Since the acrylate-methacrylate copolymer contains a polymerizable unsaturated double bond in the crosslinkable group-containing (meth)acrylate unit, the pressure-sensitive adhesive layer 22 can be cured by irradiation with active energy rays (ultraviolet rays, etc.) before the above-mentioned pick-up step. For example, irradiation with active energy rays such as ultraviolet rays generates radicals from the photopolymerization initiator, and the acrylate-methacrylate copolymer can be crosslinked by the action of these radicals. This makes it possible to reduce the adhesive strength of the pressure-sensitive adhesive layer 22 before irradiation after irradiation. This also makes it possible to smoothly peel the die-bonding sheet 10 from the pressure-sensitive adhesive layer 22. The active energy rays include ultraviolet rays, radioactive rays, and electron beams.

[0051] The polymerizable (meth)acrylate unit can be prepared by a urethane reaction after the polymerization reaction of an acrylate-methacrylate copolymer. For example, after copolymerization of an alkyl (meth)acrylate monomer and a hydroxyalkyl (meth)acrylate monomer, the hydroxy group in a part of the hydroxyalkyl (meth)acrylate unit and the isocyanate group of the isocyanate group-containing polymerizable monomer can be subjected to a urethane reaction to obtain the polymerizable (meth)acrylate unit.

[0052] The isocyanate group-containing (meth)acrylic monomer preferably has one isocyanate group and one (meth)acryloyl group in the molecule, such as 2-methacryloyloxyethyl isocyanate.

[0053] In this embodiment, the acrylate-methacrylate copolymer may contain a monomer unit other than the above-mentioned monomer units, such as N-vinyl-2-pyrrolidone or acrylonitrile units.

[0054] In the acrylate-methacrylate copolymer contained in the pressure-sensitive adhesive layer 22, the above-mentioned units (constituent units) are 1 H-NMR, 13 This can be confirmed by NMR analysis such as C-NMR, pyrolysis GC / MS analysis, infrared spectroscopy, etc. The molar ratio of the above units in the acrylate-methacrylate copolymer is usually calculated from the blending amount (charge amount) when polymerizing the acrylate-methacrylate copolymer.

[0055] Of the total monomer units (100 mol parts) in the acrylate-methacrylate copolymer, it is preferable that the proportion of crosslinkable group-containing (meth)acrylate units is 15 to 60 mol parts, and that 50 to 95% (in terms of moles) of the crosslinkable group-containing (meth)acrylate units form urethane bonds as described above. In other words, when the total monomer units are taken as 100 mol parts, the acrylate-methacrylate copolymer preferably contains 15 to 60 mol parts of crosslinkable group-containing (meth)acrylate units, and that 50 to 95% of the crosslinkable group-containing (meth)acrylate units are the polymerizable (meth)acrylate units. This allows the adhesive strength between the die bond sheet 10 and the pressure-sensitive adhesive layer 22 before curing to be maintained, while improving the releasability between the die bond sheet 10 and the pressure-sensitive adhesive layer 22 after curing.

[0056] The acrylate-methacrylate copolymer preferably contains 10 to 50 parts by mole of polymerizable (meth)acrylate units when the total monomer units are taken as 100 parts by mole. This allows the adhesive strength between the die bond sheet 10 and the pressure-sensitive adhesive layer 22 before curing to be maintained, while improving the peelability between the die bond sheet 10 and the pressure-sensitive adhesive layer 22 after curing.

[0057] Preferably, the acrylate-methacrylate copolymer has saturated alkyl acrylate units with an alkyl moiety having 7 to 11 carbon atoms and crosslinkable group-containing methacrylate units in the molecule. The crosslinkable group-containing methacrylate units preferably have hydroxy C2-C4 alkyl methacrylate units and polymerizable methacrylate units.

[0058] In this embodiment, the isocyanate compound that may be further contained in the pressure-sensitive adhesive layer 22 of the dicing tape 20 has multiple isocyanate groups in its molecule. The isocyanate compound having multiple isocyanate groups in its molecule can promote a crosslinking reaction between acrylate-methacrylate copolymers in the pressure-sensitive adhesive layer 22. Specifically, one isocyanate group of the isocyanate compound can be reacted with a hydroxy group of an acrylate-methacrylate copolymer, and the other isocyanate group can be reacted with a hydroxy group of another acrylate-methacrylate copolymer, thereby promoting a crosslinking reaction via the isocyanate compound. The isocyanate compound may be a compound synthesized through a urethane reaction or the like.

[0059] Examples of the isocyanate compound include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, and araliphatic diisocyanates.

[0060] Furthermore, examples of the isocyanate compound include polymerized polyisocyanates such as dimers and trimers of diisocyanates, and polymethylene polyphenylene polyisocyanates.

[0061] In addition, examples of the isocyanate compound include polyisocyanates obtained by reacting an excess amount of the above-mentioned isocyanate compound with an active hydrogen-containing compound, such as an active hydrogen-containing low molecular weight compound or an active hydrogen-containing high molecular weight compound. As the isocyanate compound, allophanated polyisocyanate, biureted polyisocyanate, etc. may also be used. The above isocyanate compounds can be used alone or in combination of two or more.

[0062] The isocyanate compound is preferably a reaction product of an aromatic diisocyanate and an active hydrogen-containing low molecular weight compound. The reaction rate of the isocyanate group in the reaction product of the aromatic diisocyanate is relatively slow, so that the pressure-sensitive adhesive layer 22 containing such a reaction product is prevented from being excessively hardened. The isocyanate compound is preferably one having three or more isocyanate groups in the molecule.

[0063] In this embodiment, the polymerization initiator contained in the pressure-sensitive adhesive layer 22 is a compound that can initiate a polymerization reaction by applied heat or light energy. By including a polymerization initiator in the pressure-sensitive adhesive layer 22, a cross-linking reaction between acrylate-methacrylate copolymers can be promoted when heat energy or light energy is applied to the pressure-sensitive adhesive layer 22. Specifically, a polymerization reaction between polymerizable groups can be initiated between the acrylate-methacrylate copolymers having the above-mentioned polymerizable (meth)acrylate units, thereby curing the pressure-sensitive adhesive layer 22. This reduces the adhesive strength of the pressure-sensitive adhesive layer 22, and allows the die bond sheet 10 to be easily peeled off from the cured pressure-sensitive adhesive layer 22 in the pick-up step. As the polymerization initiator, for example, a photopolymerization initiator or a thermal polymerization initiator is used. As the polymerization initiator, a general commercially available product can be used.

[0064] The pressure-sensitive adhesive layer 22 preferably contains less than 5% by mass of filler or does not contain any filler.

[0065] After curing by the above-mentioned crosslinking reaction, the pressure-sensitive adhesive layer 22 has a shear storage modulus of preferably 240 MPa or more, more preferably 350 MPa or more, and even more preferably 400 MPa or more at 25° C. The shear storage modulus is preferably 480 MPa or less, more preferably 450 MPa or less. By ensuring that the shear storage modulus is within the above range, semiconductor chips can be more effectively produced by dicing the semiconductor wafer, and in particular, chipping can be more effectively suppressed. The above-mentioned "after curing" refers to the time when the adhesive layer containing the photopolymerization initiator is exposed to ultraviolet light from a high-pressure mercury lamp at an intensity of 80 W / cm. 2 The cumulative light intensity is 300mJ / cm 2 This refers to the state after irradiation and curing so that the cured product becomes uniform (hereinafter also referred to as "after a specific curing treatment").

[0066] The shear storage modulus can be increased by increasing the number of crosslinking points in the pressure-sensitive adhesive layer 22. For example, the shear storage modulus can be increased by increasing the proportion of crosslinkable group-containing (meth)acrylate units in the acrylate-methacrylate copolymer. On the other hand, the shear storage modulus can be decreased by decreasing the number of crosslinking points in the pressure-sensitive adhesive layer 22.

[0067] The shear storage modulus is measured under the following measurement conditions. Measuring device: Viscoelasticity measuring device (for example, measuring device name "ARES" manufactured by TA Instruments) Sample size: diameter 7.9 mm, thickness 2 mm (If the thickness is less than 2 mm, multiple sheets are stacked to form a laminate.) Measurement environment: Nitrogen gas atmosphere Heating rate: 5℃ / min Measurement temperature: -40℃ to 100℃ Read the shear storage modulus value at 25°C Measurement mode: Rotation mode Frequency: 1Hz Distortion: 0.1%

[0068] After curing by the above-mentioned crosslinking reaction (after the above-mentioned specific curing treatment), the pressure-sensitive adhesive layer 22 has a surface tension of preferably 29 [dyn / cm] or more, more preferably 30 [dyn / cm] or more at 25° C. The surface tension is preferably 36 [dyn / cm] or less, more preferably 33 [dyn / cm] or less. If the surface tension is within the above range, the above-mentioned pick-up properties can be improved.

[0069] The surface tension can be adjusted appropriately by changing the types and composition ratio of the monomer units that make up the acrylate-methacrylate copolymer.

[0070] The above surface tension is calculated from the contact angle measured as follows. First, a sample for contact angle measurement is prepared. Specifically, a slide glass (manufactured by Matsunami Glass Industry Co., Ltd., product name "S9112") is attached to one side of the adhesive layer using a small roller. The untreated side of a release liner is attached to the other side of the adhesive layer using a small roller, and the other side of the adhesive layer is smoothed. After the specific curing treatment described above, the release liner is peeled off, and the contact angle is measured on the exposed surface of the adhesive layer (the other side). Specifically, the contact angles of droplets of water (HO) and methylene iodide (CHI) that come into contact with the surface of the adhesive layer are measured using a contact angle meter under conditions of 20°C and 65% relative humidity. The contact angles (contact angles 10 seconds after droplet deposition) are measured at five randomly selected points, and the average value is calculated. Subsequently, using the measured values ​​of the water contact angle θw and the methylene iodide contact angle θi, γs was calculated according to the method of Owens et al. described in Journal of Applied Polymer Science, vol. 13, pp. 1741-1747 (1969).d (dispersion component of surface free energy) and γs h (polar component of surface free energy) and γs d and γs h The value γs (=γs d +γs h ) is the surface tension of the adhesive layer. γs d (variance components) and γs h The values ​​of each (polar component) are obtained as solutions to the simultaneous equations with two unknowns shown below in Equations (1) and (2). In Equations (1) and (2), γw is the surface free energy of water, γw 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, 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 follows: γw=72.8[mJ / m 2 ] γw d =21.8 [mJ / m 2 ] γw h =51.0[mJ / m 2 ] γi=50.8[mJ / m 2 ] γi d =48.5 [mJ / m 2 ] γi h =2.3 [mJ / m 2 ]

number

[0071] The pressure-sensitive adhesive layer 22 may further contain other components in addition to the components described above. Examples of the other components include tackifiers, plasticizers, fillers, antioxidants, antioxidants, UV absorbers, light stabilizers, heat stabilizers, antistatic agents, surfactants, and release agents. The types and amounts of the other components may be appropriately selected depending on the purpose.

[0072] The pressure-sensitive adhesive layer 22 may have a thickness of 40 μm or less. The thickness of the pressure-sensitive adhesive layer 22 is preferably 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. The pressure-sensitive adhesive layer 22 may have a thickness of 1 μm or more. The shape and size of the pressure-sensitive adhesive layer 22 are usually the same as the shape and size of the base layer 21. When the thickness of the adhesive layer 22 is thinner, vibration of the semiconductor wafer directly or indirectly fixed on the adhesive layer 22 during blade dicing, for example, is more suppressed than when the thickness of the adhesive layer 22 is thicker. Therefore, the above-mentioned chipping can be more suppressed.

[0073] [Dicing tape base layer] The base layer 21 superposed on the pressure-sensitive adhesive layer 22 may have a single-layer structure or a laminated structure (for example, a two-layer structure or a three-layer structure).

[0074] The base material layer 21 may be configured with two layers or three layers. In the base material layer 21 having such a laminated structure, for example, each layer is produced by co-extrusion molding, and the multiple layers are integrated together.

[0075] The thickness (total thickness) of the base layer 21 is preferably 80 μm or more and 150 μm or less. This value is the average of measurements taken at least three randomly selected locations. Hereinafter, the thickness of the pressure-sensitive adhesive layer 22 is also the average of measurements taken in the same manner. When the thickness of the base layer 21 is 80 μm or more, stress can be applied more uniformly to the entire base layer 21, and the semiconductor wafer can be more effectively cleaved in the expanding step.

[0076] When the base layer 21 has a laminated structure (e.g., a three-layer structure) in which multiple layers are stacked, it is possible to stack a layer with a higher elastic modulus and a layer with a lower elastic modulus. Therefore, the elastic modulus of the base layer 21 can be controlled relatively easily. For example, if the elastic modulus of the base layer 21, which is composed of only one layer, is relatively high, the base layer 21 may be more likely to break during the expanding process. Furthermore, for example, the stress for cleaving the semiconductor chip is transmitted from the force stretching the dicing tape 20 during the expanding process through the base layer 21 and the adhesive layer 22. However, if the elastic modulus of the base layer 21, which is composed of only one layer, is relatively low, the stress may be less likely to be transmitted. In this way, when the base layer 21 is made up of multiple layers, the physical properties (characteristics) of each layer can be brought out. Therefore, a base layer made up of multiple layers is more likely to exhibit desired characteristics than a single-layer base layer.

[0077] Each layer of the base material layer 21 is, for example, a metal foil, a rubber sheet, or a resin film.

[0078] Each layer of the base material layer 21 may contain, for example, polyolefins such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and ethylene-propylene copolymers; ionomer resins; ethylene-vinyl acetate copolymer resins; ethylene copolymers such as ethylene-(meth)acrylic acid ester (random, 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 (aramids); polyether ether ketone (PEEK); polyimides; polyetherimides; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymers); cellulose or cellulose derivatives; silicone-containing polymers; fluorine-containing polymers, etc.

[0079] When each layer of the base material layer 21 has a resin film, the resin film may be subjected to a stretching treatment or the like to control the deformability such as elongation.

[0080] The base layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like, since it allows active energy rays such as ultraviolet rays to be applied to the pressure-sensitive adhesive layer 22 from the back side.

[0081] Each layer of the base material layer 21 may further contain an antistatic agent. The antistatic agent can prevent static electricity from building up in the base material layer 21. This can adequately prevent electrostatic breakdown of the electronic circuits in the semiconductor chip due to static electricity discharge. Furthermore, preventing static electricity can adequately prevent foreign matter such as dust from adhering to the base material layer 21.

[0082] The back side of the base material layer 21 (the side on which the adhesive layer 22 is not overlapped) may be subjected to a release treatment using a release agent (release agent) such as a silicone-based resin or a fluorine-based resin to impart releasability.

[0083] On the other hand, the surface of the base layer 21 in contact with the pressure-sensitive adhesive layer 22 may be subjected to a surface treatment to enhance adhesion to the pressure-sensitive adhesive layer 22. Examples of surface treatments that can be used include oxidation treatments using chemical or physical methods such as chromic acid treatment, ozone exposure, flame exposure, high-voltage shock exposure, and ionizing radiation treatment. In addition, the base layer 21 may be subjected to a coating treatment using a coating agent such as an anchor coating agent, a primer, or an adhesive.

[0084] <Dicing die bond film die bond sheet> As shown in FIG. 1, the die bond sheet 10 is overlaid on the adhesive layer 22 of the dicing tape 20 described above.

[0085] The thickness of the die bond sheet 10 is not particularly limited, but is, for example, 1 μm or more and 200 μm or less. Such a thickness may be 3 μm or more and 150 μm or less, or 5 μm or more and 140 μm or less. When the die bond sheet 10 is a laminate, the above thickness is the total thickness of the laminate.

[0086] The die bond sheet 10 may have a single layer structure, for example, as shown in Fig. 1. In this specification, a single layer means having only a layer formed of the same composition. A form in which multiple layers formed of the same composition are stacked is also considered a single layer. On the other hand, the die bond sheet 10 may have a multilayer structure in which layers formed of, for example, two or more different compositions are laminated. When the die bond sheet 10 has a multilayer structure, at least one layer constituting the die bond sheet 10 may contain a crosslinkable group-containing acrylic polymer described below, and may further contain a thermosetting resin as necessary.

[0087] The die bond sheet 10 contains a crosslinkable group-containing acrylic polymer having a crosslinkable group in the molecule that undergoes a crosslinking reaction by heat curing treatment. Such a crosslinkable group-containing acrylic polymer is a polymer compound in which at least (meth)acrylic acid ester monomers are polymerized.

[0088] The crosslinkable group-containing acrylic polymer generally has the crosslinkable group in a side chain. The crosslinkable group-containing acrylic polymer may have the crosslinkable group at the end of the side chain. The crosslinkable group-containing acrylic polymer may have the crosslinkable group at at least one of both ends of the main chain.

[0089] The crosslinkable group contained in the molecule of the crosslinkable group-containing acrylic polymer is not particularly limited as long as it is a functional group that undergoes a crosslinking reaction upon heat curing treatment.

[0090] Examples of the crosslinkable group include a hydroxy group and a carboxy group. These crosslinkable groups can undergo a crosslinking reaction with an epoxy group or an isocyanate group. For example, the above-mentioned crosslinkable group-containing acrylic polymer having at least one of a hydroxy group and a carboxy group in the molecule can undergo a crosslinking reaction with a compound having an epoxy group or an isocyanate group in the molecule (e.g., an epoxy resin, which will be described later).

[0091] Examples of crosslinkable groups include epoxy groups and isocyanate groups. These crosslinkable groups can undergo crosslinking reactions with hydroxy groups and carboxy groups. For example, the above-mentioned crosslinkable group-containing acrylic polymer having at least one of an epoxy group and an isocyanate group in the molecule can undergo crosslinking reactions with a compound having at least one of a hydroxy group and a carboxy group in the molecule (e.g., a phenolic resin, which will be described later).

[0092] In the present embodiment, the crosslinkable group-containing acrylic polymer contained in the die bond sheet 10 preferably contains at least one of a hydroxy group and a carboxy group as a crosslinkable group, thereby allowing the die bond sheet 10 to be better adhered to the adherend.

[0093] In the above-mentioned crosslinkable group-containing acrylic polymer, the proportion of the structural units of the crosslinkable group-containing monomer may be 0.1% by mass or more and 60.0% by mass or less, 0.5% by mass or more and 40.0% by mass or less, 1.0% by mass or more and 30.0% by mass or less, or 3.0% by mass or more and 20.0% by mass or less. The structural unit is a structure derived from each monomer after polymerization of the monomer (for example, 2-ethylhexyl acrylate, hydroxyethyl acrylate, etc.) when polymerizing the crosslinkable group-containing acrylic polymer. The same applies hereinafter.

[0094] The above-mentioned crosslinkable group-containing acrylic polymer can be synthesized by a general polymerization method using, for example, a radical polymerization initiator.

[0095] The crosslinkable group-containing acrylic polymer preferably contains, among the structural units in the molecule, the structural unit of an alkyl(meth)acrylate monomer in the largest mass proportion. Examples of the alkyl(meth)acrylate monomer include C1-C18 alkyl(meth)acrylate monomers having an alkyl group (hydrocarbon group) with 1 to 18 carbon atoms. The alkyl(meth)acrylate monomer may also be, for example, a C1-C12 alkyl(meth)acrylate monomer having an alkyl group (hydrocarbon group) with 1 to 12 carbon atoms.

[0096] Examples of the alkyl(meth)acrylate monomer include saturated linear alkyl(meth)acrylate monomers and saturated branched alkyl(meth)acrylate monomers.

[0097] Examples of saturated linear alkyl (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, etc. The number of carbon atoms in the linear alkyl group moiety is preferably 2 or more and 8 or less. Examples of saturated branched alkyl (meth)acrylate monomers include isoheptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc. The alkyl group portion may have any of an iso structure, a sec structure, a neo structure, or a tert structure.

[0098] The above-mentioned crosslinkable group-containing acrylic polymer contains a constituent unit derived from a crosslinkable group-containing monomer copolymerizable with an alkyl(meth)acrylate monomer. In this embodiment, the crosslinkable group-containing acrylic polymer is an acrylic polymer obtained by copolymerizing at least an alkyl(meth)acrylate monomer and a crosslinkable group-containing monomer. In other words, the crosslinkable group-containing acrylic polymer has a structure in which constituent units of the alkyl(meth)acrylate monomer and constituent units of the crosslinkable group-containing monomer are linked in random order.

[0099] Examples of the crosslinkable group-containing monomer include functional group-containing monomers such as carboxy group-containing (meth)acrylic monomers, acid anhydride (meth)acrylic monomers, hydroxy group-containing (meth)acrylic monomers, epoxy group- (glycidyl group-) containing (meth)acrylic monomers, isocyanate group-containing (meth)acrylic monomers, sulfonic acid group-containing (meth)acrylic monomers, phosphate group-containing (meth)acrylic monomers, acrylamide, acrylonitrile, etc. The crosslinkable group-containing monomers may have an ether group or an ester group in the molecule.

[0100] The crosslinkable group-containing acrylic polymer is preferably at least one crosslinkable group-containing monomer selected from the group consisting of a carboxy group-containing (meth)acrylic monomer, a hydroxy group-containing (meth)acrylic monomer, an epoxy group-containing (meth)acrylic monomer, and an isocyanate group-containing (meth)acrylic monomer; It is a copolymer of alkyl (meth)acrylate (particularly alkyl (meth)acrylate with an alkyl portion having 8 or less carbon atoms).

[0101] Examples of carboxy group-containing (meth)acrylic monomers include (meth)acrylic acid, mono(2-(meth)acryloyloxyethyl)succinate monomer, etc. The carboxy group may be located at the terminal portion of the monomer structure, or may be bonded to a hydrocarbon other than the terminal portion. Examples of hydroxy group-containing (meth)acrylic monomers include hydroxyethyl (meth)acrylate monomer, hydroxypropyl (meth)acrylate monomer, hydroxybutyl (meth)acrylate monomer, etc. The hydroxy group may be located at the terminal portion of the monomer structure, or may be bonded to a hydrocarbon at a portion other than the terminal portion. Examples of epoxy group-containing (meth)acrylic monomers include glycidyl (meth)acrylate monomer, 4-hydroxybutyl (meth)acrylate glycidyl ether, etc. The epoxy group may be located at the terminal portion of the monomer structure, or may be bonded to a hydrocarbon at a portion other than the terminal portion. Examples of the isocyanate group-containing (meth)acrylic monomer include 2-methacryloyloxyethyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate, 2-acryloyloxyethyl isocyanate, and 2-(2-methacryloyloxyethyloxy)ethyl isocyanate.

[0102] The die bond sheet 10 may contain a component other than the above-mentioned crosslinkable group-containing acrylic polymer. For example, the die bond sheet 10 may further contain at least one of a thermosetting resin and a thermoplastic resin other than the above-mentioned crosslinkable group-containing acrylic polymer.

[0103] Examples of the thermosetting resin include epoxy resin, phenol resin, amino resin, unsaturated polyester resin, polyurethane resin, silicone resin, thermosetting polyimide resin, etc. As the thermosetting resin, only one type or two or more types may be used.

[0104] 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, orthocresol novolac type, trishydroxyphenylmethane type, tetraphenylolethane type, hydantoin type, trisglycidyl isocyanurate type, and glycidylamine type epoxy resins.

[0105] Phenol resins can act as curing agents for epoxy resins, and examples of phenolic resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene. Examples of novolac type phenolic resins include phenol novolac resins, phenol aralkyl resins, cresol novolac resins, tert-butylphenol novolac resins, and nonylphenol novolac resins. The hydroxyl group equivalent [g / eq] of the phenolic resin may be, for example, 90 or more and 220 or less. As the phenolic resin, only one kind or two or more kinds may be employed.

[0106] In the present embodiment, the die bond sheet 10 may contain the above-mentioned crosslinkable group-containing acrylic polymer and thermosetting resin, which undergo a crosslinking reaction with each other.

[0107] For example, the die bond sheet 10 may contain an epoxy group-containing acrylic polymer as the crosslinkable group-containing acrylic polymer and a phenol resin as the thermosetting resin, whereby the epoxy groups of the crosslinkable group-containing acrylic polymer and the hydroxyl groups of the phenol resin undergo a crosslinking reaction to sufficiently harden the die bond sheet 10.

[0108] Examples of thermoplastic resins other than the above-mentioned crosslinkable group-containing acrylic polymer that can be contained in the die bond sheet 10 include natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-polyamide resin and 6,6-polyamide resin, phenoxy resin, acrylic resin that does not contain a crosslinkable functional group in the molecule, saturated polyester resin such as PET and PBT, polyamideimide resin, fluororesin, etc. As the thermoplastic resin, one kind alone or two or more kinds may be adopted.

[0109] In the die-bonding sheet 10, the content of the crosslinkable group-containing acrylic polymer is preferably 8% by mass or more and 100% by mass or less.

[0110] In the die bond sheet 10, the content ratio of the above-mentioned crosslinkable group-containing acrylic polymer relative to 100 parts by mass of organic components excluding the filler (for example, the above-mentioned crosslinkable group-containing acrylic polymer, thermosetting resin, curing catalyst, silane coupling agent, dye) is preferably 15 parts by mass or more and 100 parts by mass or less, more preferably 40 parts by mass or more and 95 parts by mass or less, and even more preferably 60 parts by mass or more. Note that by changing the content ratio of the thermosetting resin in the die bond sheet 10, the elasticity and viscosity of the die bond sheet 10 can be adjusted. On the other hand, the content of the thermosetting resin may be 40 parts by mass or less per 100 parts by mass of the organic component.

[0111] The die bond sheet 10 may or may not contain a filler. By changing the amount of filler in the die bond sheet 10, it is possible to more easily adjust the elasticity and viscosity of the die bond sheet 10. Furthermore, it is possible to adjust the physical properties of the die bond sheet 10, such as electrical conductivity, thermal conductivity, and elastic modulus.

[0112] The filler may be an inorganic filler or an organic filler, with the inorganic filler being preferred. Examples of inorganic fillers include fillers containing aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, boron nitride, and silica such as crystalline silica and amorphous silica. Examples of inorganic filler materials include simple metals such as aluminum, gold, silver, copper, and nickel, as well as alloys. Fillers such as aluminum borate whiskers, amorphous carbon black, and graphite are also acceptable. The filler may have various shapes, such as spherical, acicular, and flake-like. Only one or more of the above fillers may be used.

[0113] When the die bond sheet 10 contains a filler, the content of the filler may be 50 mass % or less of the total mass of the die bond sheet 10. The content of the filler may be, for example, 5 mass % or more.

[0114] The die bond sheet 10 may contain other components as needed, such as a curing catalyst, a flame retardant, a silane coupling agent, an ion trapping agent, and a dye. Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resin. Examples of the silane coupling agent include β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane. Examples of the ion trapping agent include hydrotalcites, bismuth hydroxide, and benzotriazole. As the other additives, only one kind or two or more kinds may be employed.

[0115] The die bond sheet 10 preferably contains the above-mentioned crosslinkable group-containing acrylic polymer, thermosetting resin, and filler, in that the elasticity and viscosity can be easily adjusted.

[0116] The dicing die bond film 1 of this embodiment may have a release liner that covers one side of the die bond sheet 10 (the side of the die bond sheet 10 that is not overlapped with the pressure-sensitive adhesive layer 22) before use. The release liner is used to protect the die bond sheet 10, and is peeled off immediately before attaching an adherend (for example, a semiconductor wafer) to the die bond sheet 10. The release liner may be, for example, a plastic film or paper whose surface has been treated with a release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide-based release agent. The release liner can be used as a support material for supporting the die bond sheet 10. The release liner is suitably used when overlaying the die bond sheet 10 on the pressure-sensitive adhesive layer 22. In detail, the die bond sheet 10 is overlaid on the pressure-sensitive adhesive layer 22 in a state where the release liner and the die bond sheet 10 are laminated, and after overlaying, the release liner is peeled off (transferred), thereby overlaying the die bond sheet 10 on the pressure-sensitive adhesive layer 22.

[0117] Next, a method for manufacturing the die bond sheet 10 and the dicing die bond film 1 of this embodiment will be described.

[0118] <Dicing die bond film manufacturing method> The manufacturing method of the dicing die bond film 1 of this embodiment is as follows: A step of producing a die bond sheet 10; A step of preparing a dicing tape (20); The method includes a step of overlapping the manufactured die bond sheet 10 and the dicing tape 20.

[0119] [Process for producing die bond sheet] The process of producing the die bond sheet 10 includes: a resin composition preparation step of preparing a resin composition for forming the die bond sheet 10; and a die-bonding sheet forming step of forming the die-bonding sheet 10 from the resin composition.

[0120] In the resin composition preparation step, for example, the above-mentioned crosslinkable group-containing acrylic polymer is mixed with either an epoxy resin, a phenolic resin, a curing catalyst, or a solvent, and each resin is dissolved in the solvent to prepare a resin composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Commercially available products can be used as these resins.

[0121] In the die-bonding sheet forming step, for example, the resin composition prepared as described above is applied to a release liner. The application method is not particularly limited, and for example, a general application method such as roll coating, screen coating, or gravure coating is used. Next, if necessary, the applied composition is solidified by a solvent removal treatment or a curing treatment, etc., to form the die-bonding sheet 10.

[0122] [Dicing tape production process] The process of producing the dicing tape includes: a synthesis step of synthesizing a (meth)acrylic polymer including an acrylate-methacrylate copolymer; a pressure-sensitive adhesive layer preparation step of preparing a pressure-sensitive adhesive layer 22 by volatilizing a solvent from a pressure-sensitive adhesive composition containing the above-mentioned (meth)acrylic polymer, an isocyanate compound, a polymerization initiator, a solvent, and other components that are appropriately added depending on the purpose; a base material layer preparation step of preparing a base material layer 21; and a lamination step of laminating the base layer 21 and the adhesive layer 22 by bonding the adhesive layer 22 and the base layer 21 together.

[0123] In the synthesis step, for example, an acrylate-methacrylate copolymer intermediate is synthesized by radically polymerizing a C6 to C12 alkyl (meth)acrylate monomer, the alkyl portion of which has 6 to 12 carbon atoms, and a hydroxy group-containing (meth)acrylic monomer. Radical polymerization can be carried out by a conventional method. For example, an acrylate-methacrylate copolymer intermediate can be synthesized by dissolving the above-mentioned monomers in a solvent, stirring the mixture while heating, and adding a polymerization initiator. Polymerization may be carried out in the presence of a chain transfer agent to adjust the molecular weight of the acrylate-methacrylate copolymer. Next, some of the hydroxy groups in the hydroxyalkyl (meth)acrylate units contained in the acrylate-methacrylate copolymer intermediate are bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer by a urethane reaction, whereby some of the hydroxyalkyl (meth)acrylate units become polymerizable (meth)acrylate units containing radically polymerizable carbon-carbon double bonds. The urethane reaction can be carried out by a conventional method. For example, an acrylate-methacrylate copolymer intermediate and an isocyanate group-containing polymerizable monomer are stirred under heating in the presence of a solvent and a urethane catalyst. This allows the isocyanate groups of the isocyanate group-containing polymerizable monomer to be urethane-bonded to some of the hydroxy groups of the acrylate-methacrylate copolymer intermediate.

[0124] In the pressure-sensitive adhesive layer preparation step, for example, a (meth)acrylic polymer containing an acrylate-methacrylate copolymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare a pressure-sensitive adhesive composition. The viscosity of the composition can be adjusted by changing the amount of solvent. Next, the pressure-sensitive adhesive composition is applied to a release liner. Typical application methods include roll coating, screen coating, and gravure coating. The applied composition is then subjected to a solvent removal treatment, solidification treatment, etc., to solidify the applied pressure-sensitive adhesive composition, thereby preparing the pressure-sensitive adhesive layer 22.

[0125] In the base layer preparation step, the base layer can be prepared by film formation using a general method. Examples of film formation methods include a calendar film formation method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, and a dry lamination method. A co-extrusion molding method may also be used. Commercially available films may also be used as the base layer 21 or as each layer constituting the base layer 21.

[0126] In the lamination step, the pressure-sensitive adhesive layer 22, which is superimposed on the release liner, is laminated on the base layer 21. The release liner may remain superimposed on the pressure-sensitive adhesive layer 22 until use. In addition, in order to promote the reaction between the crosslinking agent and the acrylate-methacrylate copolymer, and also between the crosslinking agent and the surface portion of the base layer 21, an aging treatment step may be carried out for 48 hours in an environment of 50°C after the lamination step.

[0127] Through these steps, the dicing tape 20 can be manufactured.

[0128] [Step of overlapping the die bond sheet and dicing tape] In the step of overlapping the die bond sheet 10 and the dicing tape 20, the die bond sheet 10 is attached to the adhesive layer 22 of the dicing tape 20 manufactured as described above.

[0129] In such attachment, the release liners are peeled from the pressure-sensitive adhesive layer 22 of the dicing tape 20 and the die bond sheet 10, respectively, and the die bond sheet 10 and the pressure-sensitive adhesive layer 22 are attached together so that they come into direct contact with each other. For example, they can be attached by pressure bonding. The temperature during attachment is not particularly limited, and is, for example, from 30°C to 50°C, and preferably from 35°C to 45°C. The linear pressure during attachment is not particularly limited, but is preferably from 0.1 kgf / cm to 20 kgf / cm, and more preferably from 1 kgf / cm to 10 kgf / cm.

[0130] The dicing die bond film 1 manufactured as described above through the above-mentioned steps is used, for example, as an auxiliary tool for manufacturing a semiconductor device (semiconductor integrated circuit).

[0131] The method for manufacturing a semiconductor device (method for using a dicing die bond film) will be described in more detail below.

[0132] <Method for manufacturing a semiconductor device (method for using a dicing die bond film when manufacturing a semiconductor device)> In a manufacturing method of a semiconductor device, semiconductor chips are generally cut out from a semiconductor wafer having a circuit surface formed thereon and then assembled. At this time, the dicing die bond film of this embodiment is used as a manufacturing auxiliary tool.

[0133] A method for manufacturing a semiconductor device using the above-mentioned dicing die bond film 1 is, for example, A method for manufacturing a semiconductor device, comprising: manufacturing a semiconductor device having a semiconductor chip using a dicing die bond film comprising the dicing tape and the die bond sheet overlapped on the dicing tape; a step of fixing the semiconductor wafer to the dicing tape via the die bond sheet by disposing the die bond sheet between the adhesive layer of the dicing tape and the semiconductor wafer; and a step of dividing the semiconductor wafer together with the die bond sheet into small pieces to obtain a plurality of semiconductor chips to which small pieces of the die bond sheet are attached.

[0134] Specifically, an example of a method for manufacturing a semiconductor device is as follows: A method for manufacturing a semiconductor device, which uses a dicing die bond film comprising a dicing tape having a base layer and an adhesive layer overlaid on the base layer, and a die bond sheet overlaid on the dicing tape, to manufacture a semiconductor device having a semiconductor chip. The manufacturing method of the semiconductor device of this embodiment includes a mounting step of attaching one side of a semiconductor wafer to the die bond sheet 10 of the dicing die bond film 1 described above and fixing the semiconductor wafer to the dicing tape 20 via the die bond sheet 10; and an expanding step of stretching the dicing tape (20) to cleave the semiconductor wafer together with the die bond sheet (10) at the fragile portion of the semiconductor wafer as a boundary. Furthermore, the method for manufacturing a semiconductor device of this embodiment includes a pick-up step of peeling the small pieces of die bond sheet 10 attached to the adhesive layer 22 of the dicing tape 20 from the adhesive layer 22 together with the semiconductor chip.

[0135] In more detail, an example of a method for manufacturing a semiconductor device includes, for example, a stealth dicing process in which a weak portion is formed inside a semiconductor wafer to which a backgrind tape has been attached using laser light, and the semiconductor wafer is prepared for processing into semiconductor chips (dies) by a fracturing process; a backgrinding process in which the semiconductor wafer to which the backgrind tape has been attached is ground to reduce its thickness; the mounting process in which one side of the thinned semiconductor wafer (for example, the side opposite to the circuit side) is attached to a die bond sheet 10 and the semiconductor wafer is fixed to the dicing tape 20 via the die bond sheet 10; the expanding process in which the dicing tape 20 is stretched to fractur e the semiconductor wafer to produce semiconductor chips and widen the gap between adjacent semiconductor chips; and the pick-up process in which the die bond sheet 10 is peeled off from the adhesive layer 22, and the semiconductor chip (die) is taken out with the die bond sheet 10 still attached. The manufacturing method of the semiconductor device of this embodiment further includes a die bonding process in which the die bond sheet 10 attached to the semiconductor chip is adhered to the adherend, a curing process in which the die bond sheet 10 adhered to the adherend is hardened, a wire bonding process in which the electrodes of the electronic circuit in the semiconductor chip are electrically connected to the adherend by wires, and a sealing process in which the semiconductor chip and wires on the adherend are sealed with a thermosetting resin.

[0136] The stealth dicing process is a step in the so-called SDBG (Stealth Dicing Before Grinding) process. In the stealth dicing process, as shown in FIGS. 3A to 3C, a weakened portion is formed inside the semiconductor wafer W to cleave a patterned wafer with a circuit surface formed thereon into semiconductor chips. Specifically, first, a backgrinding tape G is attached to the circuit surface of the semiconductor wafer W (see FIG. 3A). Next, with the backgrinding tape G attached, the semiconductor wafer W is subjected to a grinding process (pre-backgrinding process) using a grinding pad K until it reaches a predetermined thickness (see FIG. 3B). Then, a laser beam is applied to the thinned semiconductor wafer W to form a weakened portion inside the semiconductor wafer W (see FIG. 3C).

[0137] The dicing die bond film of this embodiment is preferably used in an SDBG (Stealth Dicing Before Grinding) process or a DBG (Dicing Before Grinding) process for manufacturing semiconductor chips by cleaving a semiconductor wafer as described above.

[0138] In the back-grinding process, as shown in FIG. 3D, the semiconductor wafer W with the back-grinding tape G attached thereto is further ground to reduce the thickness of the semiconductor wafer W to the thickness of the semiconductor chips (dies) that will be fabricated in a subsequent cleaving process. For example, the half-cut semiconductor wafer W is ground to a predetermined thickness so as not to be separated. By performing the grinding process in this manner, the semiconductor wafer W is cleaved into semiconductor chips and the die bond sheet 10 is also cleaved in a subsequent expanding process (particularly a low-temperature expanding process).

[0139] In the mounting step, as shown in Figures 4A and 4B, the semiconductor wafer W is fixed to the dicing tape 20. Specifically, a dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and the semiconductor wafer W, whose thickness has been reduced by the cutting process described above, is attached to the exposed surface of the die bond sheet 10 (see Figure 4A). Subsequently, the backgrinding tape G is peeled off from the semiconductor wafer W (see Figure 4B).

[0140] In the expanding step, as shown in FIGS. 5A to 5C, the semiconductor wafer W is cleaved to diced it into small pieces, producing diced semiconductor chips X, and the distance between the produced semiconductor chips X is increased. Specifically, a dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and then fixed to a holder H of an expanding device (see FIG. 5A). A push-up member U provided in the expanding device is pushed up from below the dicing die bond film 1, stretching the dicing die bond film 1 so as to expand it in the surface direction (see FIG. 5B). This cleaves the semiconductor wafer W under specific temperature conditions. The temperature conditions are, for example, −20 to 0°C, preferably −15 to 0°C, and more preferably −10 to −5°C. The expanded state is released by lowering the push-up member U (see FIG. 5C; this is the low-temperature expanding step). 6A and 6B, the dicing tape 20 is stretched to expand its area under higher temperature conditions (for example, 10°C to 25°C), thereby separating adjacent semiconductor chips X in the planar direction of the film surface after cleaving, and further widening the kerf (the distance between adjacent semiconductor chips) (room-temperature expanding process).

[0141] In this embodiment, the expanding process causes the dicing tape 20 to be stretched in the planar direction. If the dicing tape 20 is not heat-treated around the diced semiconductor chips, the dicing tape 20 will shrink back to its original shape in the portion overlapping the diced semiconductor chips (the central portion). To prevent this shrinkage of the dicing tape 20, a heat treatment is applied to a portion of the dicing tape 20 along the periphery of the diced semiconductor chips. The heat treatment is performed, for example, so that the surface of the heated portion of the dicing tape 20 reaches a temperature of approximately 90°C or higher and 120°C or lower. In one specific example, the heat treatment is applied to the portion of the dicing tape 20 that does not overlap the diced semiconductor chips and that follows the periphery of the diced semiconductor chips.

[0142] 3A to 3C, a blade dicing process may be performed, for example, as shown in FIG. 7, in which a semiconductor wafer W is diced into small pieces using a dicing blade. Specifically, the semiconductor wafer W is attached to the exposed surface of the die bond sheet 10, and a dicing ring R is attached to the adhesive layer 22 of the dicing tape 20. The semiconductor wafer W is then divided into a plurality of small pieces to obtain semiconductor chips X. More specifically, the die bond sheet 10 and the semiconductor wafer W are cut (so-called full cut) into small pieces using a dicing saw S (dicing blade) or the like, and the diced die bond sheet 10′ and semiconductor chips X are fabricated on the dicing tape 20.

[0143] Before the subsequent pick-up step, the adhesive layer 22 superposed on the base layer 21 is cured by irradiating the adhesive layer 22 with ultraviolet light from the base layer 21 side (curing step).

[0144] 8, in the pick-up process, the semiconductor chip X with the die bond sheet piece 10' attached thereto is peeled off from the adhesive layer 22 of the dicing tape 20. More specifically, the pin members P are raised to push up the semiconductor chip X to be picked up through the dicing tape 20. The pushed-up semiconductor chip X is held by a suction jig J.

[0145] In the die bonding process, the semiconductor chip X with the die bond sheet piece 10' attached thereto is bonded to an adherend Z. In the die bonding process, for example, as shown in FIG. 9, the semiconductor chips X with the die bond sheet piece 10' attached thereto may be stacked multiple times.

[0146] In the curing process, a heat treatment is performed at a temperature of, for example, 100°C or higher and 180°C or lower in order to increase the reactivity of the crosslinkable groups (e.g., epoxy groups) in the above-mentioned crosslinkable group-containing acrylic polymer contained in the die bond sheet piece 10' and promote the hardening of the die bond sheet piece 10'.

[0147] In the wire bonding process, a semiconductor chip X (die) and an adherend Z are connected with a wire L while being heated (see, for example, FIG. 9).

[0148] 10, the semiconductor chip X and the small piece 10′ of the die bond sheet are sealed with a thermosetting resin M such as epoxy resin. In the sealing process, a heat treatment is performed at a temperature of 100° C. or higher and 180° C. or lower to promote the curing reaction of the thermosetting resin M.

[0149] In recent years, with the further advancement of integration technology in the semiconductor industry, there has been a demand for thinner semiconductor chips (for example, a thickness of 20 μm or more and 50 μm or less) and thinner die bond sheets (for example, a thickness of 1 μm or more and 40 μm or less, preferably 7 μm or less, and more preferably 5 μm or less).

[0150] In the above-described method for manufacturing a semiconductor device (method for using a dicing die bond film), for example, after the above-described stealth dicing step, the dicing tape 20 is stretched in the planar direction with a strong force so as to expand its area in an expanding step. As a result, the semiconductor wafer W is cleaved into small pieces, and a large number of semiconductor chips X are obtained. At this time, the dicing tape 20 of this embodiment, particularly the dicing die bond film 1, can exhibit good cleavability. Furthermore, instead of the stealth dicing process described above, the semiconductor wafer W may be divided into small pieces by the blade dicing process described above to obtain a large number of semiconductor chips X. In this case, the dicing tape 20 of this embodiment, particularly the dicing die bond film 1, can prevent the semiconductor wafer from being chipped by the dicing blade, thereby preventing the above-mentioned chipping. That is, the dicing tape 20 of this embodiment, particularly the dicing die bond film 1, allows for favorable production of semiconductor chips by dicing a semiconductor wafer. Furthermore, in the above-described method for manufacturing a semiconductor device, for example, when the above-described pick-up step is carried out, the dicing tape 20 of this embodiment, particularly the dicing die bond film 1, can exhibit good pick-up properties. As described above, the dicing tape 20 of this embodiment, particularly the dicing die bond film 1, can satisfactorily carry out the production of semiconductor chips by dicing semiconductor wafers, and can also exhibit good pick-up properties.

[0151] The dicing tape and dicing die bond film of this embodiment are as exemplified above, but the present invention is not limited to the dicing tape and dicing die bond film exemplified above. That is, various forms used in general dicing tapes or dicing die bond films can be adopted within the scope that does not impair the effects of the present invention.

[0152] The matters disclosed by this specification include the following. (1) A substrate layer and a pressure-sensitive adhesive layer superimposed on one surface of the substrate layer, the pressure-sensitive adhesive layer contains a (meth)acrylic polymer containing an acrylate-methacrylate copolymer, A dicing tape in which the acrylate-methacrylate copolymer accounts for 50% or more of the (meth)acrylic polymer. (2) The acrylate-methacrylate copolymer has a crosslinkable group-containing (meth)acrylate unit capable of undergoing a crosslinking reaction in the molecule, The dicing tape according to (1) above, wherein the pressure-sensitive adhesive layer has a shear storage modulus of 240 MPa or more and 480 MPa or less at 25°C after curing by the crosslinking reaction. (3) The acrylate-methacrylate copolymer has a crosslinkable group-containing (meth)acrylate unit capable of undergoing a crosslinking reaction in the molecule, The dicing tape according to (1) or (2), wherein the pressure-sensitive adhesive layer has a surface tension of 29 dyn / cm or more and 36 dyn / cm or less at 25°C after curing by the crosslinking reaction. (4) The acrylate-methacrylate copolymer has at least an alkyl (meth)acrylate unit and a hydroxyalkyl (meth)acrylate unit in the molecule, the alkyl moiety of the alkyl (meth)acrylate unit has 7 or more carbon atoms; The dicing tape according to any one of (1) to (3) above, wherein the number of carbon atoms in the alkyl portion of the hydroxyalkyl (meth)acrylate unit is 7 or less. (5) A dicing die bond film comprising the dicing tape according to any one of (1) to (4) above and a die bond sheet superimposed on the dicing tape. [Example]

[0153] The present invention will now be described in more detail with reference to experimental examples, but the present invention is not limited to these examples.

[0154] A dicing tape was produced as follows: The dicing tape was bonded to a die bond sheet to produce a dicing die bond film.

[0155] <Creating dicing tape>

[0156] [Adhesive layer] The pressure-sensitive adhesive layers a to f were each produced as follows.

[0157] [Adhesive layer a~f] (raw material monomer) 2-Ethylhexyl acrylate (2EHA) n-Butyl acrylate (BA) 2-Hydroxyethyl acrylate (HEA) 2-Hydroxyethyl methacrylate (HEMA) Lauryl methacrylate (LMA) (Preparation of (meth)acrylic polymers including acrylate-methacrylate copolymers) A reaction vessel equipped with a condenser, nitrogen inlet tube, thermometer, and stirrer was charged with the raw materials according to the composition shown in Table 1. Azobisisobutyronitrile (AIBN) was used as a polymerization initiator at 0.4 parts by mass per 100 parts by mass of the monomers. Ethyl acetate (120 parts by mass) was added as a reaction solvent at 100 parts by mass of the monomers. The polymerization reaction was carried out in a nitrogen stream at 62°C for 6 hours and then at 75°C for 2 hours, yielding a solution containing a polymer intermediate. Next, 2-methacryloyloxyethyl isocyanate (hereinafter, MOI) (product name "Karenz MOI" manufactured by Showa Denko Materials Inc.) was added to the solution containing the polymer intermediate so that the amount was 80 mol % in molar terms relative to the total amount of HEA or HEMA. Furthermore, 0.03 mass % of dibutyltin dilaurate relative to the MOI was added as a reaction catalyst. After that, an addition reaction treatment (urethanization reaction) was carried out in an air stream at 50°C for 12 hours, yielding a (meth)acrylic polymer containing an acrylate-methacrylate copolymer. Next, a pressure-sensitive adhesive solution was prepared by adding 2.5 parts by mass of a photopolymerization initiator (product name "Omnirad 127" manufactured by IGM), 0.8 parts by mass of a polyisocyanate compound (product name "Takenate D-101A"), and 0.01 parts by mass of an antioxidant (the above-mentioned "Irganox 1010") to 100 parts by mass of the (meth)acrylic polymer (based on the amount of the starting material). The pressure-sensitive adhesive solution was applied using an applicator to the treated surface of a silicone-treated PET release liner (50 μm thick). The resulting mixture was then heated and dried at 120°C for 2 minutes to form a 10 μm-thick pressure-sensitive adhesive layer.

[0158] [Table 1]

[0159] [Base material layer] The resin film constituting the base layer is the following commercially available product. Polyolefin resin film (product name "Fanclea NED#125" manufactured by Gunze, thickness 125 μm)

[0160] [Bonding of adhesive layer and base layer] The above-mentioned base layer was laminated onto the pressure-sensitive adhesive layer formed as above, and the resulting mixture was stored at 50° C. for 24 hours to produce a dicing tape.

[0161] <Production of die bond sheet> A die bond sheet was produced as follows. Acrylic polymer (product name "SG-P3", manufactured by Nagase ChemteX Corporation, glass transition temperature 12°C, containing epoxy groups) 35 parts by mass (solid content), 45 parts by weight of epoxy resin (product name "JER1001", manufactured by Mitsubishi Chemical Corporation), 50 parts by weight of phenolic resin (product name "MEHC-7851SS", manufactured by UBE Corporation), 100 parts by weight of silica filler (product name "SO-25R", manufactured by Admatechs Co., Ltd.) 0.5 parts by mass of curing catalyst (product name "Curesol 2PHZ", manufactured by Shikoku Chemicals Corporation) The above-mentioned raw materials were added to a predetermined amount of methyl ethyl ketone and mixed to prepare a bonding composition solution having a total solid content concentration of 20 mass %. Next, the adhesive composition was applied to the silicone release-treated surface of the PET release liner using an applicator to form a coating film, which was then subjected to a heat drying treatment at 130°C for 2 minutes to produce a die-bonding sheet with a thickness of 10 μm on the PET release liner.

[0162] (Examples 1 to 5, Comparative Examples 1 to 5) [Dicing die bond film manufacturing] At room temperature, a circular die bond sheet and a dicing tape were bonded together using a laminator to produce a dicing die bond film.

[0163] <Measurement of physical properties of dicing die bond film> The physical properties of the pressure-sensitive adhesive layer constituting the dicing die bond film of each of the Examples and Comparative Examples were measured as follows.

[0164] [Proportion of acrylate-methacrylate copolymer in (meth)acrylic polymer] The proportion of the acrylate-methacrylate copolymer in the (meth)acrylic polymer was determined by the method using HPLC described above. The results are shown in Table 2.

[0165] [Shear storage modulus of the adhesive layer of the dicing tape after curing at 25°C] The details of the method for measuring the shear storage modulus of the pressure-sensitive adhesive layer are as described above. The measurement results of the modulus at 25°C are shown in Table 2.

[0166] [Surface tension of dicing tape adhesive layer after curing at 25°C] The surface tension of the pressure-sensitive adhesive layer was measured in detail as described above. The results of measuring the surface tension at 25°C are shown in Table 2.

[0167] [Table 2]

[0168] Furthermore, the performance of the dicing die bond film produced as described above was evaluated as follows.

[0169] <Performance evaluation (evaluation of chipping prevention performance)> Blade dicing was performed on a bare wafer under the following conditions, and chipping suppression performance was evaluated. (Blade dicing conditions) An 8-inch bare wafer with a thickness of 50 μm was attached to a die bond sheet of a dicing die bond film, and blade dicing was performed under the following conditions. Device: DFD6361 (DISCO) Cutting method: Step cut Wafer: 12 inches / thickness 50 μm / mirror finish Blade type: Z1 / 203O-SE 27HCDD (DISCO) Z2 / 203O-SE 27HCBB (DISCO) Dicing speed: 30~50mm / sec Rotation speed: Z1 / 40,000 rpm, Z2 / 45,000 rpm Water consumption:<1.0L / min Blade height: Z1 / 0.160mm, Z2 / 0.090mm (Evaluation of chipping suppression performance) The cut edges of the wafer after dicing with a dicing blade (the straight sections where the wafer was removed) were observed at a magnification of 300x using a laser microscope (VK-X200, manufactured by Keyence Corporation). In addition, the intersections of the cut edges of four adjacent chips in the planar direction were photographed. The photographed image was trimmed into a strip of 1156 x 110 pixels. Trimming was performed so that the length from one end to the other of the cut edges extending in one direction between the four chips, which were perpendicular to each other, matched the longitudinal length of the trimmed image (see an example in Figure 11). The image was converted to 32 bits using image processing software (Image J), ​​and then binarized (threshold 107), with the chips in white and the cut edges in black. The area ratios of the white and black areas were then calculated and evaluated according to the following criteria. Excellent (〇): Black area is less than 80% Good (△): Black area is 80% or more but less than 85% Poor (×): Black area is 85% or more

[0170] <Performance evaluation (pickup ability)> [Preparing the evaluation sample] As an evaluation sample, a dicing die bond film with a chip (die) fabricated using a bare wafer was prepared. Specifically, a bare wafer held on wafer processing tape (product name "UB-3083D" manufactured by Nitto Denko Corporation) was bonded to the die bond sheet of the dicing die bond film using a laminator. The wafer processing tape was then peeled off from the wafer. The bonding conditions were a bonding speed of 10 mm / s, a temperature of 50 to 80°C, and a pressure of 0.15 MPa.

[0171] [Wafer preparation] First, a wafer processing tape (product name "UB-3083D" manufactured by Nitto Denko Corporation) was attached to the first surface of a bare wafer (12 inches in diameter, 780 μm thick, manufactured by Tokyo Kako Co., Ltd.) where a modified region was to be formed. Next, a stealth dicing device (product name "DAL7360 (SDE05)" with a power of 0.25 W and a frequency of 80 kHz, manufactured by Disco Corporation) was used to form a modified region inside the bare wafer. Specifically, a laser beam focused on the side of the wafer closest to the first surface was irradiated from the back surface (second surface) opposite the first surface. The irradiation was carried out along the planned line for dividing the bare wafer. This resulted in the formation of a modified region for dicing inside the wafer (50 μm deep from the first surface of the wafer) in a 3 mm x 7 mm grid pattern by ablation due to multiphoton absorption. The wafer was then thinned to a thickness of 30 μm by grinding from the second side using a backgrinding machine (product name "DGP8760" manufactured by Disco Corporation). In this way, a wafer held by a wafer processing tape was formed. This wafer included sections for dicing the wafer into multiple chips (3 mm × 7 mm).

[0172] [Chip (die) manufacturing] The bare wafer prepared as described above was attached to a dicing die bond film. The bare wafer attached to the dicing die bond film was cleaved into small pieces by an expanding process. After the wafer processing tape was peeled off from the bare wafer, an expanding process was carried out using a die separator (product name "Die Separator DDS2300, manufactured by Disco Corporation"). In the expanding process, cool expanding was carried out, followed by room temperature expanding. Cool expansion was performed as follows. Specifically, a 12-inch diameter SUS ring frame (manufactured by Disco Corporation) was attached at room temperature to the area where the frame was to be attached on the adhesive layer of the dicing die bond film attached to the bare wafer. Subsequently, the bare wafer with the SUS ring frame attached was loaded into a die separator. Then, the wafer and die bond sheet were cleaved in a cool expander unit under the conditions of an expansion temperature of -15°C, an expansion speed of 100 mm / sec, and an expansion amount of 10 mm, to obtain multiple chips with die bond sheet layers. Furthermore, room temperature expansion was carried out under the conditions of a room temperature environment, an expansion speed of 1 mm / sec, and an expansion amount of 10 mm.

[0173] [Pickup ability] A pickup test was conducted on semiconductor chips with individualized die bond sheets attached using a device equipped with a pickup mechanism (product name "Die Bonder DB830Plus+" manufactured by Fasford). The pickup test was conducted with the pin member pushing up at a speed of 1 mm / sec and a pushing up distance of 300 μm. Five semiconductor chips were picked up, and the pickup performance was evaluated using the following evaluation criteria. (Evaluation criteria) Excellent (〇): Pickup success rate is 80% or higher Good (△): Pickup success rate is between 20% and 80% Poor (×): Pickup success rate is less than 20%

[0174] <Performance evaluation (semiconductor wafer cleavability)> (Preparing the evaluation sample) A dicing die bond film with a chip (die) was prepared using a bare wafer as an evaluation sample. Specifically, a bare wafer held by wafer processing tape (product name "UB-3083D", manufactured by Nitto Denko Corporation) was bonded to the die bond sheet of the dicing die bond film using a laminator. Next, the wafer processing tape was peeled off from the wafer. The bonding conditions were a bonding speed of 10 mm / sec, a temperature of 50 to 80°C, and a pressure of 0.15 MPa. (Wafer preparation) First, a wafer processing tape (product name "UB-3083D" manufactured by Nitto Denko Corporation) was attached to the first surface of a bare wafer (12 inches in diameter, 780 μm thick, manufactured by Tokyo Kako Co., Ltd.) where a modified region was to be formed. Next, a stealth dicing machine (product name "DAL7360 (SDE05)" with a power of 0.25 W and a frequency of 80 kHz, manufactured by Disco Corporation) was used to form a modified region inside the bare wafer. Specifically, a laser beam focused on the side of the wafer closest to the first surface was irradiated from the back surface (second surface) opposite the first surface. Irradiation was carried out along the planned line for dividing the bare wafer. This resulted in the formation of a modified region for dicing, forming a 3 mm x 7 mm grid within the wafer (50 μm deep from the first surface of the wafer) through ablation due to multiphoton absorption. The wafer was then thinned to a thickness of 30 μm by grinding from the second side using a backgrinding machine (product name "DGP8760" manufactured by Disco Corporation). In this way, a wafer held by a wafer processing tape was formed. This wafer included sections for dicing the wafer into multiple chips (3 mm × 7 mm). (Chip (die) manufacturing) The bare wafer prepared as described above was attached to a dicing die bond film. The bare wafer attached to the dicing die bond film was cleaved into small pieces by an expanding process. The expanding process was carried out using a die separator (product name "Die Separator DDS2300, manufactured by Disco Corporation") in a state where the wafer processing tape was peeled off from the bare wafer. In the expanding process, cool expanding was carried out, and then room temperature expanding was carried out. The cool expanding was carried out as follows. Specifically, a 12-inch diameter SUS ring frame (manufactured by Disco Corporation) was attached at room temperature to the area on the adhesive layer of the dicing die bond film attached to the bare wafer where the frame was to be attached. Subsequently, the bare wafer with the SUS ring frame attached was loaded into the die separator. Then, the cool expander unit was used. The wafer and die bond sheet were cleaved in a dicing oven at an expansion temperature of 0°C, an expansion speed of 100 mm / sec, and an expansion depth of 12 mm to obtain chips with multiple die bond sheet layers. Further, room temperature expansion was performed at a room temperature with an expansion speed of 1 mm / sec and an expansion depth of 10 mm. Then, while maintaining the expanded state, the dicing tape surrounding the outer edge of the wafer was thermally shrunk using a heater at a heat temperature of 250°C, a heat distance of 20 mm, and a rotation speed of 3° / sec. After thermal shrinkage, light was applied from the back side of the tape to observe whether the chip and die bond sheet had been cleaved. A microscope was used for more detailed confirmation. (Die bond sheet breakability) Of the total number of chips that should have been broken, the number of chips that had been broken along with the die bond sheet was checked, and the breaking rate was calculated. A breaking rate of 99% or more was evaluated as "good (◯)", 85% to less than 99% was evaluated as "fairly good (△)", and less than 85% was evaluated as "poor (×)".

[0175] As can be seen from the above evaluation results, the dicing tape (dicing die bond film) of the example was able to satisfactorily produce semiconductor chips by dicing the semiconductor wafer and exhibit good pick-up properties compared to the dicing tape (dicing die bond film) of the comparative example. In producing semiconductor chips by dicing the semiconductor wafer, the dicing tape (dicing die bond film) of the example was able to suppress chipping and had good cutting performance. [Industrial Applicability]

[0176] The dicing tape and dicing die bond film of the present invention are suitably used, for example, as auxiliary tools when manufacturing semiconductor devices (semiconductor integrated circuits). [Explanation of symbols]

[0177] 1: Dicing die bond film, 10: Die bond sheet, 20: dicing tape, 21: Base material layer, 22: Adhesive layer.

Claims

1. A substrate layer and a pressure-sensitive adhesive layer superimposed on one surface of the substrate layer, the pressure-sensitive adhesive layer comprises a (meth)acrylic polymer containing an acrylate-methacrylate copolymer, The dicing tape has a ratio of the acrylate-methacrylate copolymer to the (meth)acrylic polymer of 50% or more.

2. The acrylate-methacrylate copolymer has a crosslinkable group-containing (meth)acrylate unit capable of undergoing a crosslinking reaction in the molecule, 2. The dicing tape according to claim 1, wherein the pressure-sensitive adhesive layer has a shear storage modulus of 240 MPa or more and 480 MPa or less at 25°C after curing by the crosslinking reaction.

3. The acrylate-methacrylate copolymer has a crosslinkable group-containing (meth)acrylate unit capable of undergoing a crosslinking reaction in the molecule, 3. The dicing tape according to claim 1, wherein the pressure-sensitive adhesive layer has a surface tension of 29 dyn / cm or more and 36 dyn / cm or less at 25°C after curing by the crosslinking reaction.

4. The acrylate-methacrylate copolymer has at least an alkyl (meth)acrylate unit and a hydroxyalkyl (meth)acrylate unit in the molecule, the alkyl moiety of the alkyl (meth)acrylate unit has 7 or more carbon atoms; 3. The dicing tape according to claim 1, wherein the number of carbon atoms in the alkyl portion of the hydroxyalkyl (meth)acrylate unit is 7 or less.

5. A dicing die bond film comprising the dicing tape according to claim 1 or 2 and a die bond sheet superposed on the dicing tape.

Images