Dicing tape and dicing die bond film

Abstract

To provide a dicing tape, etc. capable of performing good division of a semiconductor wafer into a plurality of semiconductor chips and maintaining sufficient calf even when the number of division lines is relatively large.SOLUTION: The dicing tape according to the present invention is a dicing tape where an adhesive layer is stacked on a base material layer, and the tensile storage elastic modulus at -10°C is between 50 MPa and 250 MPa.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dicing tape and a dicing die bond film. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in the manufacture of semiconductor devices, it is known to use a dicing tape or a dicing die bond film to obtain semiconductor chips for die bonding. The dicing tape is constructed by laminating an adhesive layer on a base layer, and the dicing die bond film is constructed by releasably laminating a die bond layer on the adhesive layer of the dicing tape.

[0003] As a method for obtaining semiconductor chips (dies) for die bonding using the dicing die bond film, it is known to employ a method including a half-cutting process in which grooves are formed in the semiconductor wafer to process the semiconductor wafer into chips (dies) by a cleaving process, a back-grinding process in which the semiconductor wafer after the half-cutting process is ground to reduce its thickness, a mounting process in which one surface of the semiconductor wafer after the back-grinding process (for example, the surface opposite to the circuit surface) is attached to a die-bonding layer and the semiconductor wafer is fixed to a dicing tape, an expanding process in which the spacing between the half-cut processed semiconductor chips is increased, a kerf maintaining process in which the spacing between the semiconductor chips is maintained, a pick-up process in which the die-bonding layer and the adhesive layer are peeled off to remove the semiconductor chip with the die-bonding layer attached, and a die-bonding process in which the semiconductor chip with the die-bonding layer attached is attached to an adherend (for example, a mounting substrate, etc.). In the kerf maintaining process, hot air (for example, 100 to 130°C) is applied to the dicing tape to cause the dicing tape to thermally shrink, and then the dicing tape is cooled and solidified, thereby maintaining the distance (kerf) between adjacent cleaved semiconductor chips. In the expanding step, the die bond layer is cleaved into pieces having sizes corresponding to the sizes of the individual semiconductor chips.

[0004] In a method for obtaining semiconductor chips for die bonding using the above-mentioned dicing die bond film, Patent Document 1 discloses that by using a dicing tape having specific physical properties (a dicing tape having an initial elastic modulus of 200 MPa or more and 380 MPa or less at -10°C and a Tan δ (loss modulus / storage modulus) of 0.080 or more and 0.3 or less at -10°C) and performing the expanding step under low-temperature conditions of -15 to 5°C, the cleavability (e.g., ease of cleaving, uniform cleavability, etc.) of the semiconductor wafer into multiple semiconductor chips can be improved in the expanding step. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-185591 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, the size required for a semiconductor chip varies depending on the application. Furthermore, the smaller the required size of the semiconductor chip, the greater the number of grooves (fracturing lines) formed in the semiconductor wafer when expanding a semiconductor wafer of the same size to separate it into multiple semiconductor chips. The greater the number of fracturing lines, the more the dicing tape or dicing die bond film needs to be stretched in order to sufficiently widen the spacing between the semiconductor chips in the expanding process. Therefore, depending on the physical properties of the dicing tape or dicing die bond film, the dicing tape or dicing die bond film may not be stretched sufficiently even when it is necessary to stretch it further, and as a result, the spacing between the semiconductor chips may not be sufficiently widened in the expanding step. In other words, the semiconductor wafer may not be properly cut into multiple semiconductor chips. Furthermore, in the kerf maintaining step, the kerf may not be maintained sufficiently. However, even when it is necessary to stretch the dicing tape or dicing die bond film more in the expanding process, that is, when the number of cutting lines is relatively large, sufficient consideration has not been given to achieving good cutting from the cut semiconductor wafer into multiple semiconductor chips. Furthermore, sufficient consideration has not been given to maintaining the kerf adequately in the kerf maintaining step.

[0007] Therefore, an object of the present invention is to provide a dicing tape and a dicing die bond film that can perform good cleavage from a semiconductor wafer into multiple semiconductor chips and can sufficiently maintain the kerf, even when the number of cleavage lines is relatively large. [Means for solving the problem]

[0008] After extensive research, the inventors discovered that by using a dicing tape and a dicing die bond film whose tensile storage modulus at -10°C is within a predetermined range, it is possible to perform good cleavage from a semiconductor wafer into multiple semiconductor chips, even when the number of cleaving lines is relatively large, and to adequately maintain the kerf, which led to the invention.

[0009] That is, the dicing tape according to the present invention is A dicing tape having a pressure-sensitive adhesive layer laminated on a base layer, The tensile storage modulus at -10°C is 50 MPa or more and 250 MPa or less.

[0010] According to this configuration, the tensile storage modulus of the dicing tape at −10° C. is 50 MPa or more and 250 MPa or less, so the dicing tape has appropriate elasticity. Therefore, when the dicing tape is attached to a semiconductor wafer and expanded to cut the semiconductor wafer into a plurality of semiconductor chips, the dicing tape can be stretched further. As a result, even when the number of cutting lines is relatively large, the semiconductor wafer can be cut into a plurality of semiconductor chips in a satisfactory manner. In addition, the calf can be maintained sufficiently.

[0011] In the dicing tape, The loss coefficient at -10°C is preferably 0.07 or more and 0.18 or less.

[0012] According to this configuration, the loss coefficient at -10°C is 0.07 or more and 0.18 or less, so the dicing tape has appropriate hardness in addition to appropriate elasticity. Therefore, when the dicing tape is attached to a semiconductor wafer and expanded to cut the semiconductor wafer into multiple semiconductor chips, not only can the dicing tape be stretched more, but breakage of the dicing tape when stretched can be relatively suppressed. This makes it possible to perform good cutting from the semiconductor wafer into multiple semiconductor chips even when there are a relatively large number of cutting lines, and in addition to being able to adequately maintain the kerf, it is possible to relatively suppress breakage of the dicing tape during cutting.

[0013] In the dicing tape, The breaking elongation at -10°C is preferably 450% or more and 600% or less.

[0014] According to this configuration, the breaking elongation at -10°C is 450% or more and 600% or less, so the dicing tape has appropriate hardness in addition to appropriate elasticity. Therefore, when the dicing tape is attached to a semiconductor wafer and expanded to cut the semiconductor wafer into multiple semiconductor chips, not only can the dicing tape be stretched more, but breakage of the dicing tape when stretched can be relatively suppressed. This makes it possible to perform good cutting from the semiconductor wafer into multiple semiconductor chips even when there are a relatively large number of cutting lines, and in addition to being able to adequately maintain the kerf, it is possible to relatively suppress breakage of the dicing tape during cutting.

[0015] The dicing die bond film according to the present invention is a dicing tape having a pressure-sensitive adhesive layer laminated on a base layer; a die bond layer laminated on the pressure-sensitive adhesive layer of the dicing tape, The tensile storage modulus at -10°C is 50 MPa or more and 250 MPa or less.

[0016] According to this configuration, when the dicing tape is attached to a semiconductor wafer and expanded to cut the semiconductor wafer into a plurality of semiconductor chips, the dicing tape can be stretched further. As a result, even when the number of cutting lines is relatively large, the semiconductor wafer can be cut into a plurality of semiconductor chips in a satisfactory manner. In addition, the calf can be maintained sufficiently. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a dicing tape and a dicing die bond film that can perform good cleavage from a semiconductor wafer into multiple semiconductor chips and can sufficiently maintain the kerf, even when the number of cleavage lines is relatively large. [Brief explanation of the drawings]

[0018] [Figure 1]1 is a cross-sectional view showing a configuration of a dicing tape according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a configuration of a dicing die bond film according to one embodiment of the present invention. [Figure 3A] 1A and 1B are cross-sectional views schematically showing half-cut processing in a method for manufacturing a semiconductor integrated circuit. [Figure 3B] 1A and 1B are cross-sectional views schematically showing half-cut processing in a method for manufacturing a semiconductor integrated circuit. [Figure 3C] 1A and 1B are cross-sectional views schematically showing back grinding in a method for manufacturing a semiconductor integrated circuit. [Figure 3D] 1A and 1B are cross-sectional views schematically showing back grinding in a method for manufacturing a semiconductor integrated circuit. [Figure 4A] 1A to 1C are cross-sectional views schematically showing a mounting step in a method for manufacturing a semiconductor integrated circuit. [Figure 4B] 1A to 1C are cross-sectional views schematically showing a mounting step in a method for manufacturing a semiconductor integrated circuit. [Figure 5A] 1A and 1B are cross-sectional views schematically illustrating a low-temperature expanding step in a method for manufacturing a semiconductor integrated circuit. [Figure 5B] 1A and 1B are cross-sectional views schematically illustrating a low-temperature expanding step in a method for manufacturing a semiconductor integrated circuit. [Figure 5C] 1A and 1B are cross-sectional views schematically illustrating a low-temperature expanding step in a method for manufacturing a semiconductor integrated circuit. [Figure 6A] 1A and 1B are cross-sectional views schematically illustrating an expanding step at room temperature in a method for manufacturing a semiconductor integrated circuit. [Figure 6B] 1A and 1B are cross-sectional views schematically illustrating an expanding step at room temperature in a method for manufacturing a semiconductor integrated circuit. [Figure 7] 10A and 10B are cross-sectional views schematically showing a kerf maintaining step in the method for manufacturing a semiconductor integrated circuit. [Figure 8] 1A to 1C are cross-sectional views schematically showing a pickup step in a method for manufacturing a semiconductor integrated circuit. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described below.

[0020] [Dicing tape] As shown in FIG. 1, the dicing tape 10 according to this embodiment is a dicing tape in which an adhesive layer 2 is laminated on a base layer 1, and has a tensile storage modulus at -10°C of 50 MPa or more and 250 MPa or less.

[0021] As will be described in the Examples section below, the tensile storage modulus of the dicing tape 10 at −10° C. is 50 MPa or more and 250 MPa or less, which is particularly useful for dicing semiconductor wafers (for example, semiconductor wafers with a diameter of 200 mm (8 inches) or more) with an area of ​​10 mm 2 The following extremely small semiconductor chips (for example, a semiconductor chip with a roughly rectangular surface, length 4 mm x width 2 mm (area 8 mm 2 )) can be easily broken.

[0022] The inventors speculate that the reason for this is as follows. The size required for semiconductor chips varies depending on the application. As mentioned above, semiconductor chips used in NAND memory controllers have an area of ​​10 mm 2 The semiconductor chips used in NAND flash memory are generally 40mm in area or smaller. 2 For example, the surface is approximately rectangular, with a length of 12 mm and a width of 4 mm (area of ​​48 mm) 2 ) or 10mm long x 5mm wide (area 50mm 2 )) are common. Here, when semiconductor wafers of the same size are cut into semiconductor chips, the smaller the size of the semiconductor chips after cutting, the narrower the spacing between the grooves (cutting lines) formed in the semiconductor wafer in the half-cut process, and therefore the greater the number of grooves formed in the semiconductor wafer. When cleaving a semiconductor wafer with narrow groove spacing into multiple semiconductor chips, in order to ensure sufficient spacing between adjacent semiconductor chips, it is necessary to sufficiently stretch the dicing tape in the expanding process (e.g., expanding at room temperature (23±2°C)). When a semiconductor wafer is cleaved into pieces with a relatively large area, such as semiconductor chips used in NAND flash memories, the number of grooves formed in the semiconductor wafer is relatively small, so that even if a dicing tape having an initial elastic modulus of 200 MPa or more and 380 MPa or less at -10°C, as described in Patent Document 1, is used, a sufficient gap can be created between adjacent semiconductor chips. However, when a semiconductor wafer is cleaved into relatively small chips such as those used in NAND memory controllers, a relatively large number of grooves are formed in the semiconductor wafer, and therefore, if a dicing tape having an initial modulus of elasticity at -10°C of 200 MPa or more and 380 MPa or less is used in the expanding process (e.g., expanding at room temperature), the dicing tape may not be stretched sufficiently to create a sufficient gap between adjacent chips. In particular, if the initial modulus of elasticity at -10°C is set to a value near the upper limit of the above numerical range in order to make the dicing tape less likely to tear during expanding at room temperature, the dicing tape becomes relatively hard and cannot be stretched sufficiently. Furthermore, when a semiconductor wafer is diced into multiple semiconductor chips using dicing tape, in order to emphasize breakability and to make it easier to apply stress to the dicing tape, a relatively high value (for example, a value near the upper limit of the numerical range described in Patent Document 1) is often selected for the initial elastic modulus of the dicing tape at -10°C. However, even in such cases, as described above, the dicing tape becomes relatively hard and cannot be stretched sufficiently. In contrast, the dicing tape 10 of this embodiment has a tensile storage modulus of 50 MPa or more and 250 MPa or less at -10°C, and therefore has moderate elasticity, and is therefore thought to be able to be stretched sufficiently even when cutting into extremely small chips such as semiconductor chips used in NAND memory controllers. Therefore, it is believed that a sufficient gap can be created between adjacent microchips in the expanding process.

[0023] By appropriately setting the material constituting the base layer 1, the layer structure of the base layer 1, and the thickness of the base layer 1, the tensile storage modulus at -10°C can be set to 50 MPa or more and 250 MPa or less.

[0024] The dicing tape 10 according to this embodiment preferably has a loss coefficient at -10°C of 0.07 or more and 0.18 or less. This gives the dicing tape 10 an appropriate hardness in addition to an appropriate elasticity. Therefore, when the dicing tape 10 is attached to a semiconductor wafer and expanded to cut the semiconductor wafer into multiple semiconductor chips (particularly extremely small chips such as those used in NAND memory controllers), not only can the dicing tape 10 be stretched more, but breakage of the dicing tape 10 when stretched can be relatively suppressed.

[0025] The tensile storage modulus at -10°C and the loss factor at -10°C can be determined as follows. Specifically, a dicing tape having a length of 40 mm (measurement length) and a width of 10 mm is used as a test piece, and the tensile storage modulus and loss modulus of the test piece are measured using a solid viscoelasticity measuring device (for example, Model RSAIII, manufactured by Rheometric Scientific Co., Ltd.) under conditions of a frequency of 1 Hz, a strain of 0.1%, a heating rate of 10°C / min, and a chuck distance of 22.5 mm in a temperature range of -50 to 100°C. At this time, the tensile storage modulus at -10°C and the loss modulus at -10°C can be determined by reading the value at -10°C, and the loss factor at -10°C can be determined by dividing the value of the tensile storage modulus at -10°C by the value of the loss modulus at -10°C. The measurement is carried out by pulling the test piece in the MD direction (direction of resin flow).

[0026] The dicing tape 10 according to this embodiment preferably has a breaking elongation at -10°C of 450% or more and 600% or less. This gives the dicing tape 10 an appropriate hardness in addition to an appropriate elasticity. Therefore, when the dicing tape 10 is attached to a semiconductor wafer and expanded to cut the semiconductor wafer into multiple semiconductor chips (particularly extremely small chips such as those used in NAND memory controllers), not only can the dicing tape 10 be stretched more, but breakage of the dicing tape 10 when stretched can be relatively suppressed.

[0027] The breaking elongation at -10°C can be determined as follows. Specifically, a dicing tape having a length of 120 mm (measurement length, L0) and a width of 10 mm was used as a test piece, and the test piece was pulled in the longitudinal direction using a tensile tester (Autograph AG-IS, manufactured by Shimadzu Corporation) under conditions of a temperature of -10°C, a chuck distance of 50 mm, and a pulling speed of 100 mm / min, and the length (L1) at which the test piece broke was measured. Then, the breaking elongation E at −10° C. is calculated based on the following formula. Breaking elongation E = (L1 - L0) / L0 x 100

[0028] The base layer 1 supports the pressure-sensitive adhesive layer 2. The base layer 1 contains a resin. Examples of the resin contained in the base layer 1 include polyolefin, polyester, polyurethane, polycarbonate, polyether ether ketone, polyimide, polyetherimide, polyamide, wholly aromatic polyamide, polyvinyl chloride, polyvinylidene chloride, polyphenyl sulfide, fluororesin, cellulose-based resin, and silicone resin.

[0029] Examples of polyolefins include homopolymers of α-olefins, copolymers of two or more types of α-olefins, block polypropylenes, random polypropylenes, copolymers of one or more types of α-olefins with other vinyl monomers, and the like.

[0030] The α-olefin homopolymer is preferably an α-olefin homopolymer having a carbon number of 2 to 12. Examples of such homopolymers include ethylene, propylene, 1-butene, and 4-methyl-1-pentene.

[0031] Examples of copolymers of two or more α-olefins include ethylene / propylene copolymers, ethylene / 1-butene copolymers, ethylene / propylene / 1-butene copolymers, ethylene / α-olefin copolymers having 5 to 12 carbon atoms, propylene / ethylene copolymers, propylene / 1-butene copolymers, and propylene / α-olefin copolymers having 5 to 12 carbon atoms.

[0032] Examples of copolymers of one or more α-olefins with other vinyl monomers include ethylene-vinyl acetate copolymer (EVA).

[0033] The polyolefin may be an α-olefin thermoplastic elastomer, such as a combination of a propylene-ethylene copolymer and a propylene homopolymer, or a propylene-ethylene-α-olefin terpolymer having four or more carbon atoms. An example of a commercially available α-olefin-based thermoplastic elastomer is Vistamax 3980 (manufactured by ExxonMobil Chemical Corporation), which is a propylene-based elastomer resin.

[0034] The base layer 1 may contain one of the above resins, or may contain two or more of the above resins. When the adhesive layer 2 contains an ultraviolet-curable adhesive, which will be described later, the base layer 1 is preferably configured to be ultraviolet-transparent.

[0035] The base layer 1 may have a single-layer structure or a laminated structure. The base layer 1 may be obtained by non-stretch molding or by stretch molding, but is preferably obtained by stretch molding. When the base layer 1 has a laminated structure, it preferably has a layer containing an elastomer (hereinafter referred to as an elastomer layer) and a layer containing a non-elastomer (hereinafter referred to as a non-elastomer layer). By providing the base layer 1 with an elastomer layer and a non-elastomer layer, the elastomer layer can function as a stress relaxation layer that relieves tensile stress. That is, the tensile stress generated in the base layer 1 can be made relatively small, so that the base layer 1 can be made relatively stretchable while having an appropriate hardness. This improves the ability to break the semiconductor wafer into a plurality of semiconductor chips. Furthermore, the base layer 1 can be prevented from breaking and being damaged during expansion in the cleaving step. In this specification, the term "elastomer layer" refers to a low-elastic modulus layer having a lower tensile storage modulus at room temperature than a non-elastomer layer. Examples of the elastomer layer include those having a tensile storage modulus of 10 MPa or more and 100 MPa or less at room temperature, and examples of the non-elastomer layer include those having a tensile storage modulus of 200 MPa or more and 500 MPa or less at room temperature.

[0036] The elastomer layer may contain one kind of elastomer or two or more kinds of elastomers, but preferably contains an α-olefin-based thermoplastic elastomer. The non-elastomer layer may contain one type of non-elastomer or may contain two or more types of non-elastomers, but preferably contains metallocene PP, which will be described later. When the base layer 1 has an elastomer layer and a non-elastomer layer, the base layer 1 is preferably formed into a three-layer structure (non-elastomer layer / elastomer layer / non-elastomer layer) having an elastomer layer as a central layer and non-elastomer layers on both opposing sides of the central layer (see Fig. 1). In Fig. 1, one of the non-elastomer layers is shown as a first resin layer 1a, the elastomer layer is shown as a second resin layer 1b, and the other non-elastomer layer is shown as a third resin layer 3c.

[0037] Furthermore, as described above, in the kerf maintaining step, hot air (for example, 100 to 130°C) is applied to the dicing die bond film maintained in an expanded state at room temperature (for example, 23°C) to thermally shrink the dicing die bond film, and then the dicing die bond film is cooled and solidified, so it is preferable that the outermost layer of the base material layer 1 contains a resin having a melting point close to the temperature of the hot air applied to the dicing tape. This allows the melted outermost layer to be solidified more quickly by applying hot air. As a result, the kerf can be maintained more satisfactorily in the kerf maintaining step.

[0038] When the base layer 1 has a laminate structure of an elastomer layer and a non-elastomer layer, the elastomer layer contains an α-olefin-based thermoplastic elastomer, and the non-elastomer layer contains a polyolefin such as metallocene PP (described below), the elastomer layer preferably contains 50% to 100% by mass of the α-olefin-based thermoplastic elastomer relative to the total mass of the elastomers forming the elastomer layer, more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, particularly preferably 90% to 100% by mass, and optimally 95% to 100% by mass. The α-olefin-based thermoplastic elastomer content in this range enhances the affinity between the elastomer layer and the non-elastomer layer, making the base layer 1 relatively easy to extrusion mold. Furthermore, the elastomer layer can function as a stress relief layer, allowing efficient cleavage of a semiconductor wafer attached to a dicing tape.

[0039] When the base layer 1 has a laminate structure of an elastomer layer and a non-elastomer layer, the base layer 1 is preferably obtained by coextrusion molding, in which an elastomer and a non-elastomer are coextruded to form a laminate structure of an elastomer layer and a non-elastomer layer. Any appropriate coextrusion molding method commonly used in the production of films, sheets, etc. can be used as the coextrusion molding. Among the coextrusion molding methods, it is preferable to use an inflation method or a coextrusion T-die method, since the base layer 1 can be obtained efficiently and inexpensively.

[0040] When the laminated substrate layer 1 is obtained by coextrusion molding, the elastomer layer and the non-elastomer layer are heated and contacted in a molten state, so a small difference in melting points between the elastomer and the non-elastomer is preferred. A small difference in melting points prevents excessive heat from being applied to either the low-melting elastomer or the non-elastomer, thereby preventing the generation of by-products due to thermal degradation of either the low-melting elastomer or the non-elastomer. This also prevents lamination defects between the elastomer layer and the non-elastomer layer due to an excessive decrease in viscosity of either the low-melting elastomer or the non-elastomer. The difference in melting points between the elastomer and the non-elastomer is preferably 0°C or higher and 70°C or lower, more preferably 0°C or higher and 55°C or lower. The melting points of the elastomer and the non-elastomer can be measured by differential scanning calorimetry (DSC) analysis, for example, by using a differential scanning calorimeter (manufactured by TA Instruments, Model DSC Q2000) to raise the temperature to 200°C at a rate of 5°C / min in a nitrogen gas flow and determining the peak temperature of the endothermic peak.

[0041] The thickness of the base layer 1 is preferably 55 μm or more and 195 μm or less, more preferably 55 μm or more and 190 μm or less, even more preferably 55 μm or more and 170 μm or less, and optimally 60 μm or more and 160 μm or less. By setting the thickness of the base layer 1 within this range, the dicing tape can be efficiently manufactured, and the semiconductor wafer attached to the dicing tape can be efficiently cleaved. The thickness of the base layer 1 can be determined, for example, by measuring the thickness at five randomly selected points using a dial gauge (manufactured by PEACOCK, model R-205) and calculating the arithmetic mean of these thicknesses.

[0042] In the base layer 1 in which an elastomer layer and a non-elastomer layer are laminated, the ratio of the thickness of the non-elastomer layer to the thickness of the elastomer layer is preferably 1 / 25 to 1 / 3, more preferably 1 / 25 to 1 / 3.5, even more preferably 1 / 25 to 1 / 4, particularly preferably 1 / 22 to 1 / 4, and optimally 1 / 20 to 1 / 4. By setting the ratio of the thickness of the non-elastomer layer to the thickness of the elastomer layer within the above range, a semiconductor wafer attached to the dicing tape can be cleaved more efficiently.

[0043] The elastomer layer may have a single layer (1 layer) structure or a laminated structure. The elastomer layer preferably has a 1- to 5-layer structure, more preferably a 1- to 3-layer structure, even more preferably a 1- to 2-layer structure, and optimally a 1-layer structure. When the elastomer layer has a laminated structure, all layers may contain the same elastomer, or at least two layers may contain different elastomers.

[0044] The non-elastomer layer may have a single layer (1 layer) structure or a laminated structure. The non-elastomer layer preferably has a 1- to 5-layer structure, more preferably a 1- to 3-layer structure, even more preferably a 1- to 2-layer structure, and optimally a 1-layer structure. When the non-elastomer layer has a laminated structure, all layers may contain the same non-elastomer, or at least two layers may contain different non-elastomers.

[0045] The non-elastomer layer preferably contains, as a non-elastomer, a polypropylene resin (hereinafter referred to as metallocene PP) that is a polymerized product of a metallocene catalyst. Examples of metallocene PP include propylene / α-olefin copolymers that are polymerized by a metallocene catalyst. By containing metallocene PP in the non-elastomer layer, dicing tape can be produced efficiently, and a semiconductor wafer attached to the dicing tape can be efficiently cleaved. An example of commercially available metallocene PP is Wintec WFX4M (manufactured by Japan Polypropylene Corporation).

[0046] Here, the metallocene catalyst is a catalyst comprising a transition metal compound of Group 4 of the periodic table (so-called metallocene compound) containing a ligand having a cyclopentadienyl skeleton, and a co-catalyst capable of reacting with the metallocene compound to activate the metallocene compound to a stable ionic state, and optionally containing an organoaluminum compound. The metallocene compound is a bridged metallocene compound that enables stereoregular polymerization of propylene.

[0047] Among the propylene / α-olefin copolymers polymerized by a metallocene catalyst, a propylene / α-olefin random copolymer polymerized by a metallocene catalyst is preferred, and among the propylene / α-olefin random copolymers polymerized by a metallocene catalyst, one selected from a propylene / α-olefin random copolymer having 2 carbon atoms polymerized by a metallocene catalyst, a propylene / α-olefin random copolymer having 4 carbon atoms polymerized by a metallocene catalyst, and a propylene / α-olefin random copolymer having 5 carbon atoms polymerized by a metallocene catalyst is preferred, and among these, a propylene / ethylene random copolymer polymerized by a metallocene catalyst is most suitable.

[0048] The propylene / α-olefin random copolymer, which is a polymerization product of the metallocene catalyst, preferably has a melting point of 80°C or higher and 140°C or lower, particularly 100°C or higher and 130°C or lower, from the viewpoints of co-extrusion film-forming properties with the elastomer layer and cleavability of a semiconductor wafer attached to a dicing tape. The melting point of the propylene / α-olefin random copolymer, which is a polymerized product of the metallocene catalyst, can be measured by the method described above.

[0049] Here, if the elastomer layer is disposed as the outermost layer of the base layer 1, when the base layer 1 is formed into a roll, the elastomer layers disposed as the outermost layers are likely to block (stick together). This makes it difficult to unwind the base layer 1 from the roll. In contrast, in a preferred embodiment of the base layer 1 having the above-described laminated structure, a non-elastomer layer / elastomer layer / non-elastomer layer is disposed, i.e., a non-elastomer layer is disposed as the outermost layer, and the base layer 1 in this embodiment has excellent blocking resistance. This makes it possible to prevent delays in the production of semiconductor devices using the dicing tape 10 due to blocking.

[0050] The non-elastomer layer preferably contains a resin having a melting point of 100° C. or higher and 130° C. or lower, and a molecular weight dispersity (mass average molecular weight / number average molecular weight) of not more than 5. An example of such a resin is metallocene PP. By including such a resin in the non-elastomer layer, the non-elastomer layer can be cooled and solidified more quickly in the kerf-maintaining step, and therefore, shrinkage of the base layer 1 can be more sufficiently suppressed after the dicing tape is heat-shrunk. This allows the kerf to be maintained more sufficiently in the kerf maintaining step.

[0051] The adhesive layer 2 contains an adhesive and adheres to the adhesive layer 2 to hold the semiconductor wafer to be diced into semiconductor chips.

[0052] The adhesive may be one whose adhesive strength can be reduced by an external action during use of the dicing tape 10 (hereinafter referred to as an adhesive reduction type adhesive).

[0053] When a reduced-adhesion adhesive is used as the adhesive, the adhesive layer 2 can be in either a state where it exhibits relatively high adhesive strength (hereinafter referred to as a high-adhesion state) or a state where it exhibits relatively low adhesive strength (hereinafter referred to as a low-adhesion state) during use of the dicing tape 10. For example, when a semiconductor wafer attached to the dicing tape 10 is subjected to cleavage, the high-adhesion state is used to prevent the multiple semiconductor chips separated by cleavage of the semiconductor wafer from lifting up or peeling off from the adhesive layer 2. On the other hand, to pick up the multiple semiconductor chips separated after cleaving the semiconductor wafer, the low-adhesion state is used to make it easier to pick up the multiple semiconductor chips from the adhesive layer 2.

[0054] The reduced-tack adhesive may be, for example, an adhesive that can be cured by irradiation with radiation during use of the dicing tape 10 (hereinafter referred to as a radiation-curable adhesive).

[0055] Examples of the radiation-curable adhesive include adhesives that are cured by irradiation with electron beams, ultraviolet rays, α rays, β rays, γ rays, or X-rays. Among these, it is preferable to use an adhesive that is cured by ultraviolet irradiation (ultraviolet-curable adhesive).

[0056] Examples of the radiation-curable adhesive include additive-type radiation-curable adhesives that contain a base polymer such as an acrylic polymer and a radiation-polymerizable monomer component or a radiation-polymerizable oligomer component having a functional group such as a radiation-polymerizable carbon-carbon double bond.

[0057] The acrylic polymer may include a polymer containing a monomer unit derived from a (meth)acrylic acid ester, such as a (meth)acrylic acid alkyl ester, a (meth)acrylic acid cycloalkyl ester, or a (meth)acrylic acid aryl ester.

[0058] The pressure-sensitive adhesive layer 2 may contain an external crosslinking agent. Any external crosslinking agent can be used as long as it can react with the acrylic polymer base polymer to form a crosslinked structure. Examples of such external crosslinking agents include polyisocyanate compounds, epoxy compounds, polyol compounds, aziridine compounds, and melamine-based crosslinking agents.

[0059] Examples of the radiation-polymerizable monomer component include urethane (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4-butanediol di(meth)acrylate. Examples of the radiation-polymerizable oligomer component include various oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based oligomers. The content ratio of the radiation-polymerizable monomer component or radiation-polymerizable oligomer component in the radiation-curable adhesive is selected within a range that appropriately reduces the adhesiveness of the adhesive layer 2.

[0060] The radiation-curable adhesive preferably contains a photopolymerization initiator, such as an α-ketol compound, an acetophenone compound, a benzoin ether compound, a ketal compound, an aromatic sulfonyl chloride compound, a photoactive oxime compound, a benzophenone compound, a thioxanthone compound, camphorquinone, a halogenated ketone, an acylphosphinoxide, or an acylphosphonate.

[0061] The pressure-sensitive adhesive layer 2 may contain, in addition to the above components, a crosslinking accelerator, a tackifier, an antioxidant, a colorant such as a pigment or a dye, and the like.

[0062] The thickness of the pressure-sensitive adhesive layer 2 is preferably 1 μm or more and 50 μm or less, more preferably 2 μm or more and 30 μm or less, and even more preferably 5 μm or more and 25 μm or less.

[0063] [Dicing die bond film] Next, the dicing die bond film 20 will be described with reference to Fig. 2. In the description of the dicing die bond film 20, the description of the portions that overlap with the dicing tape 10 will not be repeated.

[0064] As shown in Figure 2, the dicing die bond film 20 of this embodiment comprises a dicing tape 10 having an adhesive layer 2 laminated on a base layer 1, and a die bond layer 3 laminated on the adhesive layer 2 of the dicing tape 10. In the dicing die bond film 20, a semiconductor wafer is attached onto the die bond layer 3. When a semiconductor wafer is cleaved using the dicing die bond film 20, the die bond layer 3 is also cleaved together with the semiconductor wafer. The die bond layer 3 is cleaved into pieces of a size corresponding to the size of each of the individual semiconductor chips. This allows semiconductor chips with the die bond layer 3 to be obtained. As described above, the dicing tape 10 of the dicing die bond film 20 has a tensile storage modulus at -10°C of 50 MPa or more and 250 MPa or less.

[0065] The dicing tape 10 of the dicing die bond film 20 preferably has a loss coefficient at -10°C of 0.07 or more and 0.18 or less. Moreover, the dicing tape 10 of the dicing die bond film 20 preferably has a breaking elongation at -10°C of 450% or more and 600% or less.

[0066] The die bond layer 3 preferably has thermosetting properties. By including at least one of a thermosetting resin and a thermoplastic resin having a thermosetting functional group in the die bond layer 3, the die bond layer 3 can be given thermosetting properties.

[0067] When the die bond layer 3 contains a thermosetting resin, examples of such a thermosetting resin include epoxy resin, phenol resin, amino resin, unsaturated polyester resin, polyurethane resin, silicone resin, and thermosetting polyimide resin. Among these, it is preferable to use an epoxy resin.

[0068] Examples of epoxy resins 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.

[0069] Examples of phenolic resins used as curing agents for epoxy resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene.

[0070] When the die bond layer 3 contains a thermoplastic resin having a thermosetting functional group, for example, an acrylic resin containing a thermosetting functional group can be used as such a thermoplastic resin. Examples of the acrylic resin in the acrylic resin containing a thermosetting functional group include those containing a monomer unit derived from a (meth)acrylic acid ester. In the case of a thermosetting resin having a thermosetting functional group, a curing agent is selected depending on the type of the thermosetting functional group.

[0071] The die bond layer 3 may contain a thermosetting catalyst from the viewpoint of sufficiently promoting the curing reaction of the resin component and increasing the curing reaction rate. Examples of the thermosetting catalyst include imidazole-based compounds, triphenylphosphine-based compounds, amine-based compounds, and trihalogenborane-based compounds.

[0072] The die bond layer 3 may contain a thermoplastic resin. The thermoplastic resin functions as a binder. Examples of the thermoplastic resin 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 polyamide 6 and polyamide 6,6, phenoxy resin, acrylic resin, saturated polyester resin such as PET and PBT, polyamide-imide resin, and fluororesin. Only one of the above thermoplastic resins may be used, or two or more may be used in combination. As the thermoplastic resin, acrylic resin is preferred from the viewpoint that it has few ionic impurities and high heat resistance, making it easier to ensure connection reliability by the die bond layer.

[0073] The acrylic resin is preferably a polymer containing a monomer unit derived from a (meth)acrylic acid ester as the most abundant monomer unit by mass. Examples of (meth)acrylic acid esters include (meth)acrylic acid alkyl esters, (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid aryl esters. The acrylic resin may also contain a monomer unit derived from another component copolymerizable with the (meth)acrylic acid ester. Examples of the other component include functional group-containing monomers such as carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphate group-containing monomers, acrylamides, and acrylonitriles, as well as various polyfunctional monomers. From the viewpoint of realizing high cohesive strength in the die bond layer, the acrylic resin is preferably a copolymer of a (meth)acrylic acid ester (particularly, a (meth)acrylic acid alkyl ester having an alkyl group with 4 or less carbon atoms), a carboxy group-containing monomer, a nitrogen atom-containing monomer, and a polyfunctional monomer (particularly, a polyglycidyl-based polyfunctional monomer), and more preferably a copolymer of ethyl acrylate, butyl acrylate, acrylic acid, acrylonitrile, and polyglycidyl (meth)acrylate.

[0074] The die bond layer 3 may contain one or more other components as needed, such as a flame retardant, a silane coupling agent, and an ion trapping agent.

[0075] The thickness of the die bond layer 3 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 100 μm or less.

[0076] The dicing die bond film 20 according to this embodiment is used, for example, as an auxiliary tool for manufacturing semiconductor integrated circuits. A specific example of the use of the dicing die bond film 20 will be described below. In the following, an example will be described in which a dicing die bond film 20 having a single base layer 1 is used.

[0077] The method for manufacturing a semiconductor integrated circuit includes a half-cutting process in which grooves are formed in the semiconductor wafer to process the semiconductor wafer into chips (dies) by a cleaving process, a back-grinding process in which the semiconductor wafer after the half-cutting process is ground to reduce its thickness, a mounting process in which one side of the semiconductor wafer after the back-grinding process (e.g., the side opposite the circuit side) is attached to a die bond layer 3 and the semiconductor wafer is fixed to a dicing tape 10, an expanding process in which the spacing between the half-cut semiconductor chips is increased, a kerf maintaining process in which the spacing between the semiconductor chips is maintained, a pick-up process in which the die bond layer 3 is peeled from the adhesive layer 2 to remove the semiconductor chip (die) with the die bond layer 3 attached, and a die-bonding process in which the semiconductor chip (die) with the die bond layer 3 attached is adhered to an adherend. When these processes are performed, the dicing tape (dicing die-bonding film) of this embodiment is used as a manufacturing aid.

[0078] In the half-cut process, as shown in FIGS. 3A and 3B, a half-cut process is performed to cleave the semiconductor integrated circuit into small pieces (dies). Specifically, a wafer processing tape T is attached to the surface of the semiconductor wafer W opposite the circuit surface (see FIG. 3A). A dicing ring R is also attached to the wafer processing tape T (see FIG. 3A). With the wafer processing tape T attached, grooves for division are formed (see FIG. 3B). In the back-grinding process, as shown in FIGS. 3C and 3D, the semiconductor wafer is ground to reduce its thickness. Specifically, a back-grinding tape G is attached to the surface with the grooves formed, while the wafer processing tape T that was initially attached is peeled off (see FIG. 3C). With the back-grinding tape G attached, the semiconductor wafer W is ground until it reaches a predetermined thickness (see FIG. 3D).

[0079] 4A and 4B, in the mounting step, after a dicing ring R is attached to the adhesive layer 2 of the dicing tape 10, a half-cut semiconductor wafer W is attached to the exposed surface of the die bond layer 3 (see FIG. 4A). Thereafter, the backgrinding tape G is peeled off from the semiconductor wafer W (see FIG. 4B).

[0080] In the expanding step, as shown in FIGS. 5A to 5C, the dicing ring R is fixed to a holder H of an expanding device. A push-up member U provided in the expanding device is used to push up the dicing die bond film 20 from below, thereby stretching the dicing die bond film 20 so as to spread it in the planar direction (see FIG. 5B). As a result, the half-cut semiconductor wafer W is cleaved under specific temperature conditions. The temperature conditions are, for example, −20 to 5°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). 6A and 6B, the dicing tape 10 is stretched to expand its area under higher temperature conditions (for example, room temperature (23°C)), thereby separating adjacent cleaved semiconductor chips in the planar direction of the film surface and further increasing the gap between them. Here, in the dicing die bond film 20 according to this embodiment, the tensile storage modulus of the dicing tape 10 at −10° C. is 50 MPa or more and 250 MPa or less, so that it is particularly suitable for dicing a semiconductor wafer (for example, a semiconductor wafer with a diameter of 200 mm (8 inches)) into a semiconductor wafer with an area of ​​10 mm , such as that used in a NAND memory controller. 2 The following extremely small semiconductor chips (for example, semiconductor chips with a substantially rectangular surface and a length of 4 mm and a width of 2 mm) can be adequately cleaved. Furthermore, if the loss coefficient of the dicing tape 10 at -10°C is set to 0.07 or more and 0.18 or less, not only can the dicing tape 10 be adequately broken into extremely small semiconductor chips such as those described above, but it is also possible to relatively prevent the dicing tape 10 from breaking when the dicing tape 10 is stretched and broken into extremely small semiconductor chips such as those described above. Furthermore, if the breaking elongation of the dicing tape 10 at -10°C is set to 450% or more and 600% or less, not only can the dicing tape 10 be adequately broken into extremely small semiconductor chips such as those described above, but breaking of the dicing tape 10 can be relatively suppressed when the dicing tape 10 is stretched and broken into extremely small semiconductor chips such as those described above.

[0081] In the kerf maintaining process, as shown in FIG. 7, hot air (e.g., 100 to 130°C) is applied to the dicing tape 10 to cause it to thermally shrink, and then the dicing tape 10 is cooled and solidified, thereby maintaining the distance (kerf) between adjacent cleaved semiconductor chips. Here, in the dicing die bond film 20 according to this embodiment, the tensile storage modulus of the dicing tape 10 at -10°C is 50 MPa or more and 250 MPa or less, so that the kerf can be sufficiently maintained after being cleaved into tiny semiconductor chips.

[0082] 8, in the pick-up process, the semiconductor chip with the die bond layer 3 attached thereto is peeled off from the adhesive layer 2 of the dicing tape 10. More specifically, the pin members P are raised to push up the semiconductor chip to be picked up through the dicing tape 10. The pushed-up semiconductor chip is held by the suction jig J.

[0083] In the die bonding step, the semiconductor chip with the die bonding layer 3 attached thereto is bonded to an adherend. In the above-mentioned manufacturing of the semiconductor integrated circuit, an example has been described in which the dicing die bond film 20 is used as an auxiliary tool, but the semiconductor integrated circuit can also be manufactured in the same manner as above when the dicing tape 10 is used as an auxiliary tool.

[0084] The dicing tape and dicing die bond film according to the present invention are not limited to the above-described embodiments. Furthermore, the dicing tape and dicing die bond film according to the present invention are not limited by the above-described effects. The dicing tape and dicing die bond film according to the present invention can be modified in various ways without departing from the spirit of the present invention. [Example]

[0085] The present invention will now be described in more detail with reference to examples. The following examples are intended to explain the present invention in more detail, but are not intended to limit the scope of the present invention.

[0086] [Example 1] <Forming of base layer> A two-type, three-layer extrusion T-die molding machine was used to mold a substrate layer with a three-layer structure of layers A / B / C (layer B is the central layer, and layers A and C are laminated on both sides of layer B as outer layers). Metallocene PP (trade name: Wintec WFX4M, manufactured by Japan Polypropylene Corporation) was used as the resin for layers A and C, and EVA (trade name: Evaflex EV250, manufactured by DuPont-Mitsui Polychemicals) was used as the resin for layer B. The extrusion was carried out at a die temperature of 190°C. That is, layers A, B, and C were extruded at 190°C. The thickness of the substrate layer obtained by extrusion was 100 µm. The thickness ratio (layer thickness ratio) of layers A, B, and C was layer A:layer B:layer C = 1:10:1. After the formed base layer was sufficiently solidified, the solidified base layer was wound into a roll to form a roll body. <Creating dicing tape> The adhesive composition was applied to one surface of the rolled substrate layer using an applicator to a thickness of 10 μm. The substrate layer after application of the adhesive composition was dried by heating at 110° C. for 3 minutes to form an adhesive layer, thereby obtaining a dicing tape. The pressure-sensitive adhesive composition was prepared as follows. First, a first resin composition was obtained by mixing 173 parts by mass of INA (isononyl acrylate), 54.5 parts by mass of HEA (hydroxyethyl acrylate), 0.46 parts by mass of AIBN (2,2'-azobisisobutyronitrile), and 372 parts by mass of ethyl acetate. Next, the first resin composition was added to a round-bottom separable flask (volume 1 L) of a polymerization experimental apparatus equipped with a thermometer, a nitrogen inlet tube, and a stirring blade, and while stirring the first resin composition, the liquid temperature of the first resin composition was brought to room temperature (23°C), and the atmosphere inside the round-bottom separable flask was replaced with nitrogen for 6 hours. While continuing to flow nitrogen into the round-bottom separable flask, the first resin composition was stirred and the liquid temperature of the first resin composition was maintained at 62°C for 3 hours, and then at 75°C for another 2 hours to polymerize the INA, HEA, and AIBN to obtain a second resin composition. Thereafter, the flow of nitrogen into the round-bottom separable flask was stopped. After the second resin composition was cooled to room temperature, 52.5 parts by mass of 2-isocyanatoethyl methacrylate (manufactured by Showa Denko K.K., trade name "Karends MOI (registered trademark)") and 0.26 parts by mass of dibutyltin dilaurate IV (manufactured by Wako Pure Chemical Industries, Ltd.) were added to the second resin composition as a compound having a polymerizable carbon-carbon double bond, and the resulting third resin composition was stirred in an atmospheric air at a liquid temperature of 50°C for 24 hours. Next, to the third resin composition, 0.75 parts by mass of Coronate L (isocyanate compound) and 2 parts by mass of Omnirad127 (photopolymerization initiator) were added, respectively, per 100 parts by mass of polymer solids, and then the third resin composition was diluted with ethyl acetate to a solids concentration of 20% by mass to prepare a pressure-sensitive adhesive composition. <Production of dicing die bond film> 100 parts by mass of acrylic resin (manufactured by Nagase ChemteX Corporation, trade name "SG-P3", glass transition temperature 12°C), 46 parts by mass of epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "JER1001"), 51 parts by mass of phenolic resin (manufactured by Meiwa Chemical Industry Co., Ltd., trade name "MEH-7851ss"), 191 parts by mass of spherical silica (manufactured by Admatechs Co., Ltd., trade name "SO-25R"), and 0.6 parts by mass of a curing catalyst (manufactured by Shikoku Chemical Industry Co., Ltd., trade name "Curesol PHZ") were added to and mixed with methyl ethyl ketone to obtain a die bond composition with a solids concentration of 20% by mass. Next, the die bond composition was applied to a thickness of 10 μm using an applicator onto the silicone-treated surface of a PET separator (thickness 50 μm) serving as a release liner, and dried at 130°C for 2 minutes to remove the solvent from the die bond composition, thereby obtaining a die bond sheet in which a die bond layer was laminated on the release liner. Next, the side of the die bond sheet on which the release sheet was not laminated was attached to the adhesive layer of the dicing tape, and then the release liner was peeled off from the die bond layer to obtain a dicing die bond film having a die bond layer.

[0087] The dicing tape obtained as above was measured for tensile storage modulus at -10°C and loss modulus at -10°C as follows, and the loss factor at -10°C was calculated. The breaking elongation at -10°C was calculated by measuring the length of the test piece at break as follows. Furthermore, the ability to break into very small chips using the dicing die bond film during expansion and the ability to maintain the kerf were evaluated.

[0088] (Tensile storage modulus and loss factor) A test piece measuring 40 mm in length (measurement length) x 10 mm in width was cut out from the dicing tape of Example 1, and the tensile storage modulus and loss modulus of the test piece were measured using a solid viscoelasticity measuring device (model RSAIII, manufactured by Rheometric Scientific Co., Ltd.) in the temperature range of -50 to 100°C under the conditions of a frequency of 1 Hz, a strain of 0.1%, a heating rate of 10°C / min, and a chuck distance of 22.5 mm. At that time, the value at -10°C was read to determine the tensile storage modulus at -10°C and the loss modulus at -10°C. The loss factor at -10°C was calculated by dividing the tensile storage modulus at -10°C by the loss factor at -10°C.

[0089] (breaking elongation) A test piece having a length of 120 mm (measurement length, L0) x width of 10 mm was cut out from the dicing tape of Example 1, and the test piece was pulled in the longitudinal direction using a tensile tester (Autograph AG-IS, manufactured by Shimadzu Corporation) under conditions of a measurement temperature of -10°C, a chuck distance of 50 mm, and a pulling speed of 100 mm / min, and the length (L1) at which the test piece broke was measured. Then, the breaking elongation E at −10° C. was calculated based on the following formula. Breaking elongation E = (L1 - L0) / L0 x 100

[0090] (Ability to break into extremely small chips) A bare wafer (diameter 300 mm) and a dicing ring were attached to the dicing die bond film of Example 1. Next, the semiconductor wafer and the die bond layer were cleaved using a die separator DDS2300 (manufactured by Disco Corporation), and the cleavability into ultra-small chips was evaluated. The bare wafer was cleaved into bare chips (ultra-small chips) measuring 2 mm long x 2 mm wide x 0.030 mm thick.

[0091] The breakability was evaluated in detail as follows. First, the bare wafer and the die bond layer 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 14 mm to obtain a semiconductor chip with a die bond layer. Next, expansion was performed at room temperature, an expansion speed of 1 mm / sec, and an expansion amount of 8 mm. Then, while maintaining the expanded state, the dicing die bond film at the boundary with the outer edge of the bare wafer was thermally shrunk under conditions of a heat temperature of 250°C, a heat distance of 18 mm, and a rotation speed of 5° / sec. Next, the fractured portion of the semiconductor chip with the die bond layer was observed under a microscope, and the fracture rate was calculated. A fracture rate of 90% or more was evaluated as ◯, and a fracture rate of less than 90% was evaluated as ×.

[0092] (Evaluation of kerf maintenance) A bare wafer (diameter 300 mm, hereinafter also referred to as a circular wafer) and a dicing ring were attached to the dicing die bond film according to Example 1. Next, the bare wafer and the die bond layer were cleaved using a die separator DDS2300 (manufactured by Disco Corporation), and the kerf retention after cleaving was evaluated. The bare wafer was cleaved into bare chips (microchips) measuring 2 mm in length, 2 mm in width, and 0.030 mm in thickness.

[0093] The kerf retention was evaluated in detail as follows. First, the bare wafer and the die bond layer 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 14 mm to obtain a plurality of bare chips with a die bond layer. Next, room temperature expansion was performed at room temperature, an expansion speed of 1 mm / sec, and an expansion amount of 5 mm. Then, while maintaining the expanded state, the dicing die bond film at the boundary with the outer edge of the bare wafer was thermally shrunk under conditions of a heat temperature of 250°C, a heat distance of 18 mm, and a rotation speed of 5° / sec. Next, the kerf was measured using a digital microscope (VHX-6000, manufactured by Keyence Corporation). Specifically, after heat expansion (after thermal shrinkage), the distance between one chip and another chip in the cleaved portion (hereinafter also referred to as the distance) was observed with the digital microscope and the distance was measured. The distance was measured at five randomly selected locations in both the MD and TD directions. The smallest distance measured was used as the kerf. If the kerf was 30 μm or more, it was evaluated as ○ (the kerf was maintained), and if the kerf was less than 30 μm, it was evaluated as × (the kerf was not maintained). The five arbitrarily selected locations are four locations on the outermost periphery of the circular wafer, spaced apart by approximately 90° in the circumferential direction, and the vicinity of the center of the circular wafer.

[0094] [Example 2] A dicing tape and a dicing die bond film according to Example 2 were obtained in the same manner as in Example 1, except that a first polymer blend (a blend of Evaflex EV250 and HDPE (high-density polyethylene). The mass ratio was EV250:HDPE=90:10. Manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was used for the B layer of the base material layer. Furthermore, for the dicing tape of Example 2, the tensile storage modulus at -10°C and the loss modulus at -10°C were measured in the same manner as in Example 1, and the breaking elongation at -10°C and the loss factor at -10°C were calculated. Furthermore, in the same manner as in Example 1, the ability to break the dicing die bond film into very small chips during expansion and the ability to maintain the kerf were evaluated.

[0095] [Example 3] A dicing tape and a dicing die bond film according to Example 3 were obtained in the same manner as in Example 1, except that the base material layer had a single-layer structure and Evaflex P1007 (manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was used as the resin constituting the resin layer. In addition, for the dicing tape of Example 3, the tensile storage modulus at -10°C and the loss modulus at -10°C were measured in the same manner as in Example 1, and the breaking elongation at -10°C and the loss factor at -10°C were calculated. Furthermore, in the same manner as in Example 1, the ability to break the dicing die bond film into very small chips during expansion and the ability to maintain the kerf were evaluated.

[0096] [Comparative Example 1] A dicing tape and a dicing die bond film according to Comparative Example 1 were obtained in the same manner as in Example 1, except that a second polymer blend (a blend of Evaflex EV250 and HDPE (high-density polyethylene). The mass ratio was EV250:HDPE=80:20. Manufactured by DuPont-Mitsui Polychemicals Co., Ltd.) was used for the B layer of the base material layer. Furthermore, for the dicing tape of Comparative Example 1, the tensile storage modulus at -10°C and the loss modulus at -10°C were measured in the same manner as in Example 1, and the breaking elongation at -10°C and the loss factor at -10°C were calculated. Furthermore, in the same manner as in Example 1, the ability to break the dicing die bond film into very small chips during expansion and the ability to maintain the kerf were evaluated.

[0097] Comparative Example 2 A dicing tape and a dicing die bond film according to Comparative Example 2 were obtained in the same manner as in Example 1, except that Evaflex V523 (manufactured by DuPont-Mitsui Polychemicals) was used for the B layer of the base material layer. Furthermore, for the dicing tape of Comparative Example 2, the tensile storage modulus at -10°C and the loss modulus at -10°C were measured in the same manner as in Example 1, and the breaking elongation at -10°C and the loss factor at -10°C were calculated. Furthermore, in the same manner as in Example 1, the ability to break the dicing die bond film into very small chips during expansion and the ability to maintain the kerf were evaluated.

[0098] The tensile storage modulus at -10°C and the loss modulus at -10°C were measured for the dicing tape of each example, and the breaking elongation at -10°C and the loss factor at -10°C were calculated. The results of evaluating the ability of the dicing die bond film of each example to break into extremely small chips and the kerf retention are shown in Table 1 below.

[0099] [Table 1]

[0100] From Table 1, it can be seen that the dicing tapes of Examples 1 to 3 all have tensile storage modulus values ​​at -10°C in the range of 50 MPa or more and 250 MPa or less, and that the dicing die bond films of Examples 1 to 3 are excellent in terms of their ability to be broken into extremely small chips and their ability to maintain kerf. Furthermore, as can be seen from Table 1, the dicing tapes according to Examples 1 to 3 all had loss coefficient values ​​at -10°C in the range of 0.07 or more and 0.18 or less, and breaking elongation values ​​at -10°C in the range of 450% or more and 600% or less. In contrast, the dicing tapes of Comparative Examples 1 and 2 both had tensile storage modulus values ​​at -10°C outside the range of 50 MPa or more and 250 MPa or less, and it can be seen that the dicing die bond films of Comparative Examples 1 and 2 were inferior in terms of their ability to break into extremely small chips and their ability to maintain kerf. Furthermore, as can be seen from Table 1, the dicing tapes according to Comparative Examples 1 and 2 had loss coefficient values ​​outside the range of 0.07 or more and 0.18 or less at -10°C, and the breaking elongation values ​​outside the range of 450% or more and 600% or less at -10°C. In particular, when the dicing die bond film according to Comparative Example 1 was used to evaluate the ability to break into extremely small chips and the kerf retention, damage (tears) that were problematic in practical use were observed in the dicing tape. The evaluation of the ability to break extremely small chips and the evaluation of the ability to maintain the kerf shown in Table 1 are for the dicing die bond film, but it is expected that results similar to those shown in Table 1 will also be obtained for the dicing tape contained in the dicing die bond film. [Explanation of symbols]

[0101] 1 Base material layer 2. Adhesive layer 3 Die bond layer 10 Dicing tape 20 Dicing die bond film 1a 1st resin layer 1b 2nd resin layer 1c 3rd resin layer G Backgrind Tape H Holder J suction jig T Wafer Processing Tape U Push-up member W Semiconductor wafer

Claims

1. A dicing tape having a pressure-sensitive adhesive layer laminated on a base layer, The tensile storage modulus at −10° C. is 50 MPa or more and 250 MPa or less, The breaking elongation at -10°C is 450% or more and 600% or less. Dicing tape.

2. The loss coefficient at -10°C is 0.07 or more and 0.18 or less. The dicing tape according to claim 1 .

3. The base layer contains polyethylene, polypropylene, poly 1-butene, poly(4-methyl-1-pentene), ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / propylene / 1-butene copolymer, propylene / 1-butene copolymer, ethylene-vinyl acetate copolymer, or α-olefin thermoplastic elastomer. The dicing tape according to claim 1 or 2.

4. a dicing tape having a pressure-sensitive adhesive layer laminated on a base layer; A die bond layer laminated on the pressure-sensitive adhesive layer of the dicing tape, The dicing tape has a tensile storage modulus of 50 MPa or more and 250 MPa or less at −10° C., and a breaking elongation of 450% or more and 600% or less at −10° C.; Dicing die bond film.

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