Dicing die bond film

Abstract

To provide a dicing die bond film or the like capable of both sufficiently opening kerfs between semiconductor chips after an expanding process, and suppressing variation in kerfs depending on the part.SOLUTION: A dicing die bond film includes a dicing tape having a base layer and an adhesive layer superimposed on the base layer, and a die bond sheet overlapping the dicing tape, and the dicing tape has an elastic modulus at 120°C of 0.10 MPa or more, and the dicing tape has a heat shrinkage rate of 6% or more at 120°C.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, dicing die bond films used in the manufacture of semiconductor devices 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 stealth dicing process in which a fragile portion is formed in the semiconductor wafer using a laser beam to separate the semiconductor wafer into small semiconductor chips (dies), 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 the dicing tape via the die bond sheet, an expanding process in which the dicing tape is stretched in the radial direction of the semiconductor wafer to separate the semiconductor wafer with the fragile portion formed together with the die bond sheet and widen the gap between adjacent semiconductor chips (dies), a pick-up process in which the die bond sheet is peeled off from the adhesive layer to remove the semiconductor chip with the die bond sheet attached, a die bond process in which the semiconductor chip with the die bond sheet attached is attached to an adherend via the die bond sheet, 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 manufacturing method of the semiconductor device as described above, for example, after the above-mentioned expanding process is performed, the dicing tape may sag around the cleaved semiconductor chips, and adjacent semiconductor chips that have once been spaced apart may come into contact with each other. In response to this, a dicing die bond film is known in which the length of the dicing tape after being heated at a high temperature is specified relative to the length of the dicing tape before being heated at a high temperature in order to suppress the sagging of the dicing tape as described above and prevent contact between adjacent semiconductor chips (for example, Patent Document 1).

[0006] Specifically, in the dicing die bond film described in Patent Document 1, the second length in the MD direction of the dicing tape after heating at 100°C for 1 minute is 95% or less of the first length in the MD direction of the dicing tape (100%) before the heating. The dicing die bond film described in Patent Document 1 can prevent the dicing tape from sagging around multiple cleaved semiconductor chips when the dicing tape is stretched, which allows a sufficient separation distance (kerf) between adjacent semiconductor chips and prevents contact between the semiconductor chips. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-115775 Summary of the Invention [Problem to be solved by the invention]

[0008] However, it cannot be said that sufficient research has yet been conducted into dicing die bond films that not only ensure a sufficient spacing (kerf) between adjacent semiconductor chips but also prevent the spacing (kerf) from varying from location to location.

[0009] Therefore, an object of the present invention is to provide a dicing die bond film that can both sufficiently space the kerfs between semiconductor chips after the expanding step and suppress variations in the kerfs depending on the location. [Means for solving the problem]

[0010] In order to solve the above problems, the dicing die bond film according to the present invention comprises a dicing tape having a base layer and a pressure-sensitive adhesive layer overlaid on the base layer, and a die bond sheet overlaid on the dicing tape, The dicing tape at 120°C Tensile storage The elastic modulus is 0.10 MPa or more, The dicing tape is characterized in that its heat shrinkage rate at 120°C is 6% or more. [Effects of the Invention]

[0011] According to the dicing die bond film of the present invention, it is possible to both ensure sufficient kerf spacing between semiconductor chips after the expanding step and suppress variations in the kerf depending on the location. [Brief explanation of the drawings]

[0012] [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 an example of a base layer of a dicing tape in the dicing die bond film 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] 10 is a schematic view showing a heat treatment after an expanding step in a method for manufacturing a semiconductor device, viewed from one side in the thickness direction of a semiconductor chip. [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 to 5C are cross-sectional views schematically illustrating 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. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, one embodiment of the dicing die bond film according to the present invention will be described with reference to the drawings.

[0014] 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 that is 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.

[0015] 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.

[0016] <Dicing tape for dicing die bond film> The dicing tape 20 is usually a long sheet and is stored in a rolled state until it is used. 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 is then cut and used.

[0017] The dicing tape 20 includes a base layer 21 and an adhesive layer 22 superposed on the base layer 21 .

[0018] Dicing tape 20 at 120℃ Tensile storage Elasticity The rate is, 0.10 MPa or more. Therefore, it is possible to suppress the variation in the distance (kerf) between adjacent semiconductor chips depending on the location. The reason why the variation in the distance (kerf) is suppressed will be explained in detail later.

[0019] The above dicing tape 20 at 120°C Tensile storage The elastic modulus is preferably 0.20 MPa or more, and more preferably 0.30 MPa or more. Tensile storage A higher modulus of elasticity allows for more consistent kerf variation. Tensile storage The elastic modulus may be 0.70 MPa or less. Tensile storage By setting the modulus of elasticity to 0.70 MPa or less, the dicing tape 20 can be thermally shrunk more effectively.

[0020] Dicing tape 20 at 120℃ Tensile storage The elastic modulus can be increased by, for example, increasing the content of resin such as polypropylene having a relatively high elastic modulus in the base layer 21. On the other hand, by decreasing the content of resin such as polypropylene having a relatively high elastic modulus in the base layer 21, the above Tensile storage The elastic modulus can be reduced.

[0021] The above Tensile storage Elasticity The rate is , is measured under the following measurement conditions. Measurement equipment: Solid viscoelasticity measuring equipment (for example, measurement equipment name "RSA-G2" manufactured by TA Instruments) Sample size: initial length 40 mm, width 10 mm Heating rate: 10℃ / min Measurement temperature: 120°C in the temperature range of -40°C to 150°C Chuck distance: 20mm Frequency: 1Hz Distortion: 0.1% The value of the tensile storage modulus E' is Tensile storage The elastic modulus was calculated.

[0022] The thermal shrinkage rate of the dicing tape 20 at 120°C is 6% or more. Therefore, it is possible to provide a sufficient kerf between the semiconductor chips after the expanding step. The reason why it is possible to provide a sufficient kerf between the semiconductor chips will be explained in detail later.

[0023] The heat shrinkage rate is preferably 7% or more, more preferably 12% or more, and even more preferably 17% or more. A larger heat shrinkage rate allows for a larger kerf between the semiconductor chips. The heat shrinkage rate may be 70% or less, 60% or less, or 25% or less.

[0024] The heat shrinkage rate of the dicing tape 20 at 120°C can be increased by increasing the content of resin with relatively high heat shrinkability (such as ethylene-vinyl acetate copolymer resin) in the base material layer 21, or by increasing the vinyl acetate ratio in the ethylene-vinyl acetate copolymer resin that can be contained in the base material layer 21. On the other hand, the heat shrinkage rate can be reduced by decreasing the content of resin with relatively high heat shrinkability (such as ethylene-vinyl acetate copolymer resin) in the base material layer 21.

[0025] The thermal shrinkage rate is measured under the following conditions. Specifically, the dicing tape 20 is cut into a strip of 30 mm width and 120 mm length. Reference lines are drawn across the width at 10 mm, 100 mm, and 10 mm positions along the longitudinal direction. One end of the cut test piece is clamped with a clip, closer to the reference line than the longitudinal end. The dicing tape 20 is hung together with the clip in a hot air drying oven set to 120°C and heated for 1 minute while ensuring that no load other than its own weight is applied to the dicing tape 20. After heating, the distance between the reference lines of the test piece is measured. The thermal shrinkage rate is calculated by expressing the shrinkage (100 mm - the distance between the reference lines after heating) as a percentage relative to the distance between the reference lines before heating (100 mm).

[0026] [Dicing tape base layer] In this embodiment, 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 three-layer structure).

[0027] Each layer of the base material layer 21 is, for example, a metal foil, a fiber sheet such as paper or cloth, a rubber sheet, or a resin film. Examples of the fiber sheet that constitutes the base material layer 21 include paper, woven fabric, and nonwoven fabric. Examples of materials for the resin film include polyolefins such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and ethylene-propylene copolymers; ethylene copolymers such as ethylene-vinyl acetate copolymer (EVA), ionomer resins, ethylene-(meth)acrylic acid copolymers, and ethylene-(meth)acrylic acid ester (random or 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 ketones (PEEK); polyimides; polyetherimides; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymers); cellulose or cellulose derivatives; silicone-containing polymers; and fluorine-containing polymers. These may be used alone or in combination of two or more.

[0028] The base layer 21 preferably contains a polymer material, more preferably an ethylene-vinyl acetate copolymer resin and a polypropylene resin. Each layer of the base layer 21 is preferably made of a resin film such as an ethylene-vinyl acetate copolymer resin or a polypropylene resin. This allows the base layer 21 to more fully combine relatively high heat shrinkability with a relatively high elastic modulus. When the base layer 21 has a resin film, the resin film may be subjected to a stretching process or the like to control the deformability such as elongation.

[0029] The surface of the base layer 21 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. Additionally, 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.

[0030] The base layer 21 is preferably made up of a plurality of layers, more preferably made up of at least three layers, and even more preferably made up of three layers. By having base layer 21 have a laminated structure of multiple layers (e.g., a three-layer structure), it is possible to laminate a layer with a higher elastic modulus and a layer with a lower elastic modulus, and therefore the elastic modulus of base layer 21 can be controlled relatively easily. For example, if base layer 21 consisting of only one layer has a relatively high elastic modulus, lifting of the semiconductor chip and tearing of base layer 21 may be somewhat more likely to occur during the expanding process. Furthermore, for example, the stress for cleaving the semiconductor chip is transmitted from the force stretching dicing tape 20 during the expanding process via base layer 21 and adhesive layer 22. However, if base layer 21 consisting of only one layer has a relatively low elastic modulus, the stress may be somewhat less transmitted. Furthermore, by having the base layer 21 have a laminated structure of multiple layers (for example, a three-layer structure), the thermal shrinkage rate of the base layer 21 can be controlled relatively easily for the same reasons as above. In this way, by configuring the base material layer 21 with multiple layers, it is possible to bring out the physical properties (characteristics) of each layer, and therefore a base material layer configured with multiple layers is more likely to exhibit the desired characteristics than a single-layer base material layer.

[0031] As shown in FIG. 2, the base layer 21 is composed of three layers: a first base layer 21a, a second base layer 21b, and a third base layer 21c. In the three-layer base layer 21, the first base layer 21a and the third base layer 21c, which are disposed on both sides of the base layer 21, preferably contain polypropylene resin, and the second base layer 21b, which is disposed between the first base layer 21a and the third base layer 21c, preferably contains ethylene-vinyl acetate copolymer resin. This allows the base layer 21 to exhibit the properties of polypropylene resin, which has a relatively high elastic modulus at high temperatures, as well as the properties of ethylene-vinyl acetate copolymer resin, which has a relatively high thermal shrinkage rate at high temperatures. This effectively ensures sufficient spacing between semiconductor chips after the expanding process and minimizes kerf variation across different locations. In the base layer 21, for example, the layer overlapping the adhesive layer 22 is the first base layer 21a, and the layer furthest from the adhesive layer 22 is the third base layer 21c. The second base material layer 21b is disposed between the first base material layer 21a and the third base material layer 21c.

[0032] The three-layer substrate layer 21 preferably has a first substrate layer 21a and a third substrate layer 21c each containing a non-elastomeric material, and a second substrate layer 21b disposed between these layers and containing an elastomeric material. An elastomeric material is a polymeric material with a modulus of elasticity of 200 MPa or less at room temperature. An elastomer is typically a polymeric material that exhibits rubber elasticity at room temperature (23°C). On the other hand, a non-elastomeric material is a polymeric material with a modulus of elasticity of more than 200 MPa at room temperature. The base material layer 21 having such a three-layer laminate structure is formed, for example, by producing each layer by co-extrusion molding and integrating the three layers.

[0033] In the three-layer base layer 21, the ratio of the thickness of the inner layer to the total thickness of the outer layers (thickness of the second base layer 21b / total thickness of the first base layer 21a and the third base layer 21c) is preferably not less than 1 and not more than 10. Furthermore, the thicknesses of the first base layer 21a and the third base layer 21c may be approximately the same, and for example, the ratio of the thickness of the first base layer 21a to the thickness of the third base layer 21c may be not less than 0.9 and not more than 1.1.

[0034] The non-elastomeric material preferably includes at least a polyolefin such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene, etc. The polypropylene may be a metallocene polypropylene synthesized by a metallocene catalyst.

[0035] On the other hand, the elastomer material preferably contains at least ethylene-vinyl acetate copolymer (EVA), which may contain 5% to 35% by mass of vinyl acetate structural units.

[0036] 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.

[0037] More preferably, the first base material layer 21a and the third base material layer 21c each independently have a thickness of 1 μm or more and 15 μm or less, and the second base material layer 21b has a thickness of 70 μm or more and 120 μm or less, which has the advantage that the physical properties (characteristics) of each layer in the base material layer 21 are more suitably reflected in the base material layer 21.

[0038] In the above-described base material layer 21, at least one of the first base material layer 21a and the third base material layer 21c preferably further contains an antistatic agent. This prevents static electricity from building up in the base material layer 21. This effectively prevents electrostatic breakdown of the electronic circuits in the semiconductor chip due to static electricity discharge. Furthermore, preventing static electricity also effectively prevents foreign matter such as dust from adhering to the base material layer 21.

[0039] An antistatic agent is a compound that, when incorporated into each layer constituting the base layer, improves the antistatic performance of each layer compared to before incorporation. Examples of antistatic agents include low-molecular-weight antistatic agents such as surfactants, conductive particles such as carbon black, and polymeric antistatic agents. Polymeric antistatic agents are preferred. Polymeric antistatic agents have conductive units in their molecules that serve as charge paths, and are less susceptible to humidity and less likely to bleed out from each layer constituting the base layer. For example, by incorporating a polymeric antistatic agent into a resin to form a resin film and then employing this resin film in the first base layer 21a or the third base layer 21c, the base layer can maintain stable antistatic performance over time.

[0040] The antistatic agent is preferably at least one selected from the group consisting of polyolefin-polyethylene glycol copolymer, polyolefin-polyamide copolymer, polyethylene glycol-polyamide copolymer, polyethylene glycol-(meth)acrylate copolymer, polyethylene glycol-epichlorohydrin copolymer, ionomer, and a mixture of a polymer and an ionic compound (e.g., a metal salt such as a lithium salt).

[0041] 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. 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.

[0042] Of the surfaces of the layers constituting the base layer 21, the surface farthest from the adhesive layer 22 has a surface resistivity of 1.00×10 9 [Ω / sq.] or more 1.00×10 12 [Ω / sq.] or less. For example, in Fig. 2, the surface resistivity of the exposed surface of the third base material layer 21c is preferably within the above-mentioned range. This allows electric charges to be more sufficiently released to the outside of the base material layer 21, thereby more sufficiently preventing charging in the base material layer 21.

[0043] The surface resistivity can be increased by increasing the amount of antistatic agent contained in the layer having the surface on which the surface resistivity is measured, or by using an antistatic agent that further increases the surface resistivity. On the other hand, the surface resistivity can be decreased by decreasing the amount of antistatic agent contained, or by using an antistatic agent that further decreases the surface resistivity. Note that commercially available products can be used as the substrate layer 21 having the desired surface resistivity.

[0044] The surface resistivity is measured under the following conditions. Specifically, using a high resistivity meter (e.g., "Hiresta UP" manufactured by Mitsubishi Chemical Corporation), the dicing tape 20 is left standing for 2 hours under conditions of 23°C ± 2°C and 50% RH ± 5%. Thereafter, the surface resistivity of the back side of the base layer 21 of the dicing tape (the side not overlapped by the adhesive layer 22) is measured under the above conditions. The measurement conditions are an applied voltage of 500V and 1 minute.

[0045] [Adhesive layer of dicing tape] In this embodiment, the pressure-sensitive adhesive layer 22 contains, for example, an acrylic copolymer, an isocyanate compound, and a polymerization initiator. The pressure-sensitive adhesive layer 22 may have a thickness of 5 μm or more and 40 μm or less. 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.

[0046] In this embodiment, the pressure-sensitive adhesive layer 22 contains at least an acrylic copolymer having, as monomer units in the molecule, an alkyl (meth)acrylate unit and a crosslinkable group-containing (meth)acrylate unit. In the acrylic copolymer, some of the crosslinkable group-containing (meth)acrylate units have a radically polymerizable carbon-carbon double bond. The acrylic copolymer contains 15 to 60 molar parts of crosslinkable group-containing (meth)acrylate units per 100 molar parts of alkyl (meth)acrylate units, and 50 to 95 molar % of the crosslinkable group-containing (meth)acrylate units contain a radically polymerizable carbon-carbon double bond. In this specification, the term "(meth)acrylate" refers to at least one of methacrylate (methacrylic acid ester) and acrylate (acrylic acid ester). The same applies to the term "(meth)acrylic."

[0047] The acrylic copolymer has 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 acrylic copolymer. In other words, the monomer units are derived from the monomers used to polymerize the acrylic copolymer. Each side chain in the acrylic copolymer is contained in each monomer unit that constitutes the main chain.

[0048] 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.

[0049] 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 8 or more and 22 or less carbon atoms.

[0050] The acrylic copolymer preferably contains, as alkyl (meth)acrylate units, long-chain alkyl (meth)acrylate units in which the alkyl moiety has 8 or more carbon atoms, and more preferably contains long-chain saturated alkyl (meth)acrylate units in which the alkyl moiety is a saturated hydrocarbon having 8 to 22 carbon atoms.

[0051] The acrylic copolymer preferably has the highest proportion (in terms of moles) of long-chain alkyl (meth)acrylate units having 8 or more carbon atoms among all monomer units in the molecule, and more preferably has the highest proportion (in terms of moles) of long-chain alkyl (meth)acrylate units having 9 or more carbon atoms. For example, the long-chain alkyl (meth)acrylate units may account for 50% to 80% of all monomer units in terms of moles.

[0052] The long-chain 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 long-chain 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 8 to 12 carbon atoms.

[0053] The acrylic copolymer preferably contains, as the alkyl (meth)acrylate units, saturated branched alkyl (meth)acrylate units having an alkyl moiety with 8 to 10 carbon atoms, and saturated linear alkyl (meth)acrylate units having an alkyl moiety with 12 to 14 carbon atoms.

[0054] 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. Specifically, examples of the saturated branched alkyl (meth)acrylate unit include isoheptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and isostearyl (meth)acrylate units. Among these, at least one of the isononyl (meth)acrylate unit and the 2-ethylhexyl (meth)acrylate unit is preferred.

[0055] 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. Specifically, saturation Straight chain Examples of the alkyl (meth)acrylate unit include 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.

[0056] The acrylic copolymer may contain one type of alkyl (meth)acrylate unit alone, or may contain two or more types of alkyl (meth)acrylate units.

[0057] The acrylic copolymer preferably contains, as an alkyl (meth)acrylate unit, at least one selected from the group consisting of a 2-ethylhexyl (meth)acrylate unit, an isononyl (meth)acrylate unit, and a lauryl (meth)acrylate unit.

[0058] 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. In other words, some of the crosslinkable group-containing (meth)acrylate units have unreacted hydroxy groups, and the other part (all others) have no hydroxy groups but have radically polymerizable carbon-carbon double bonds.

[0059] The acrylic copolymer has, as the crosslinkable group-containing (meth)acrylate unit, a hydroxy group-containing (meth)acrylate unit in which a hydroxy group is bonded to an alkyl moiety having four or less carbon atoms. When the pressure-sensitive adhesive layer 22 contains an isocyanate compound, the isocyanate group of the isocyanate compound and the hydroxy group of the hydroxy group-containing (meth)acrylate unit can easily react with each other. By allowing the acrylic copolymer having a hydroxyl group-containing (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 acrylic copolymer to be sufficiently gelled. As a result, the pressure-sensitive adhesive layer 22 can maintain its shape while exhibiting adhesive performance.

[0060] The hydroxy group-containing (meth)acrylate unit is preferably a hydroxy group-containing C2-C4 alkyl (meth)acrylate unit in which an OH group is bonded to an alkyl moiety having from 2 to 4 carbon atoms. The term "C2 to C4 alkyl" refers to the number of carbon atoms in the hydrocarbon moiety that is ester-bonded to the (meth)acrylic acid. In other words, the hydroxy group-containing 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-C4 alkyl is usually a saturated hydrocarbon. For example, the hydrocarbon portion of the C2-C4 alkyl is a linear saturated hydrocarbon or a branched saturated hydrocarbon. It is preferable that the hydrocarbon portion of the C2-C4 alkyl does not contain a polar group containing oxygen (O), nitrogen (N), or the like.

[0061] Examples of the hydroxy group-containing C2-C4 alkyl(meth)acrylate unit include hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxy n-butyl(meth)acrylate, and hydroxy isobutyl(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.

[0062] The acrylic copolymer contains, as the crosslinkable group-containing (meth)acrylate unit, a polymerizable (meth)acrylate unit having a radically polymerizable carbon-carbon double bond (polymerizable unsaturated double bond) in the side chain.

[0063] 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 hydroxy group-containing (meth)acrylate unit.

[0064] Since the acrylic copolymer contains a radically polymerizable carbon-carbon 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 acrylic 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 bond sheet 10 from the pressure-sensitive adhesive layer 22. The active energy rays include ultraviolet rays, radioactive rays, and electron beams.

[0065] The polymerizable (meth)acrylate unit can be prepared by a urethane reaction after the polymerization reaction of an acrylic copolymer. For example, after copolymerization of an alkyl (meth)acrylate monomer with a hydroxyl group-containing (meth)acrylic monomer, the hydroxyl group in a part of the hydroxyl group-containing (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.

[0066] 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.

[0067] In this embodiment, the acrylic copolymer may contain a monomer unit other than the above-mentioned monomer units, such as (meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, or acrylonitrile units.

[0068] In the acrylic copolymer contained in the pressure-sensitive adhesive layer 22, the above-mentioned units (constituent units) are 1 H-NMR, 13This 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 acrylic copolymer is usually calculated from the blending amounts (charge amounts) when the acrylic copolymer is polymerized.

[0069] The acrylic copolymer preferably contains 15 to 60 mol parts of crosslinkable group-containing (meth)acrylate units per 100 mol parts of alkyl (meth)acrylate units, and 50 mol % to 95 mol % of the crosslinkable group-containing (meth)acrylate units form urethane bonds as described above. In other words, the acrylic copolymer preferably contains 15 to 60 mol parts of crosslinkable group-containing (meth)acrylate units per 100 mol parts of alkyl (meth)acrylate units, and 50 mol % to 95 mol % of the crosslinkable group-containing (meth)acrylate units are polymerizable (meth)acrylate units having a radical polymerizable carbon-carbon double bond. 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.

[0070] The acrylic copolymer preferably contains 19 to 55 molar parts, more preferably 23 molar parts or more, of polymerizable (meth)acrylate units relative to 100 molar parts of alkyl (meth)acrylate units, which 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.

[0071] 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 acrylic 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 acrylic copolymer, and the other isocyanate group can be reacted with a hydroxy group of another acrylic 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.

[0072] Examples of the isocyanate compound include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, and araliphatic diisocyanates.

[0073] Furthermore, examples of the isocyanate compound include polymerized polyisocyanates such as dimers and trimers of diisocyanates, and polymethylene polyphenylene polyisocyanates.

[0074] 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.

[0075] 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.

[0076] 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 acrylic 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 acrylic copolymers having polymerizable (meth)acrylate units containing radically polymerizable carbon-carbon double bonds, 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.

[0077] 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.

[0078] <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.

[0079] 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.

[0080] 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.

[0081] The peel strength between the die bond sheet 10 and the adhesive layer 22 of the dicing tape 20 before curing of the adhesive layer 22 (the peel strength when neither the die bond sheet 10 nor the adhesive layer 22 is cured) may be 0.30 [N / 20 mm] or more, or 0.50 [N / 20 mm] or more. Moreover, the peel strength before curing may be 3.00 [N / 20 mm] or less, less than 2.50 [N / 20 mm], or 2.00 [N / 20 mm] or less. The peel strength between the die bond sheet 10 and the adhesive layer 22 of the dicing tape 20 after curing of the adhesive layer 22 (the peel strength after the die bond sheet 10 is uncured and the adhesive layer 22 has sufficiently cured) may be 0.03 [N / 20 mm] or more, or 0.05 [N / 20 mm] or more, or 0.35 [N / 20 mm] or less, or 0.25 [N / 20 mm] or less. In order to sufficiently harden the adhesive layer 22, for example, an intensity of 300 mJ / cm 2 The adhesive layer 22 is irradiated with ultraviolet light.

[0082] The peel strength between the pressure-sensitive adhesive layer 22 and the die bond sheet 10 after curing is measured by the following measurement method. If necessary, first, the release liner is peeled off from the die bond sheet 10 to expose one side of the die bond sheet 10. Next, a backing tape (for example, product name "ELP BT315" manufactured by Nitto Denko Corporation) is attached to the exposed side of the die bond sheet 10. A high-pressure mercury lamp (product name "UM-810" 60 mW / cm manufactured by Nitto Seiki Co., Ltd.) is used to measure the peel strength. 2 ) from the substrate layer side with an intensity of 300mJ / cm 2 The adhesive layer is cured by irradiating it with ultraviolet light. Thereafter, a measurement sample is prepared by cutting out the adhesive layer 22 to have dimensions of 50 mm wide x 100 mm long. A T-peel test is performed on the prepared measurement sample using a tensile tester (for example, product name "AUTOGRAPH AGX-V" manufactured by Shimadzu Corporation). The test conditions are a temperature of 23°C and a tensile speed of 300 mm / min. The peel strength before curing of the adhesive layer 22 is measured in the same manner as above, except that a measurement sample is prepared by cutting out the adhesive layer 22 from the uncured adhesive layer 22 to have dimensions of 20 mm wide x 100 mm long.

[0083] For example, the peeling force can be increased by increasing the proportion of alkyl (meth)acrylate units having a small number of carbon atoms in the alkyl moiety or by increasing the proportion of hydroxyl group-containing (meth)acrylate units in the molecules of the acrylic copolymer contained in the pressure-sensitive adhesive layer 22. On the other hand, the peeling force can be decreased by increasing the proportion of alkyl (meth)acrylate units having a large number of carbon atoms in the alkyl moiety or by decreasing the proportion of hydroxyl group-containing (meth)acrylate units in the molecules of the acrylic copolymer contained in the pressure-sensitive adhesive layer 22.

[0084] The die bond sheet 10 contains a crosslinkable group-containing acrylic polymer having a crosslinkable group in the molecule that causes 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.

[0085] 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.

[0086] 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.

[0087] 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).

[0088] 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).

[0089] 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.

[0090] 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. When the above ratio is 0.1% by mass or more, it is possible to more sufficiently proceed with curing when the die bond sheet 10 is subjected to a thermal curing treatment. On the other hand, when the above ratio is 60.0% by mass or less, it is possible to appropriately suppress the crosslinking reactivity of the crosslinkable group-containing acrylic polymer and improve stability over time. 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.

[0091] The above-mentioned crosslinkable group-containing acrylic polymer can be synthesized by a general polymerization method using, for example, a radical polymerization initiator.

[0092] The crosslinkable group-containing acrylic polymer preferably contains alkyl(meth)acrylate monomers in the largest proportion by mass among the constituent units in the molecule. Examples of the alkyl(meth)acrylate monomers include C1-C18 alkyl(meth)acrylate monomers having an alkyl group (hydrocarbon group) with 1 to 18 carbon atoms.

[0093] Examples of the alkyl(meth)acrylate monomer include saturated linear alkyl(meth)acrylate monomers and saturated branched alkyl(meth)acrylate monomers.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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).

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] In the die bond sheet 10, the content of the crosslinkable group-containing acrylic polymer is preferably 8% by mass or more and 100% by mass or less, more preferably 30% by mass or more, and even more preferably 40% by mass or more.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] When the die bond sheet 10 contains a filler, the content of the filler may be 50 mass % or less, 40 mass % or less, or 30 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] Next, a method for manufacturing the die bond sheet 10 and the dicing die bond film 1 of this embodiment will be described.

[0115] <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.

[0116] <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.

[0117] 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.

[0118] 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.

[0119] <Process for producing dicing tape> The process of producing the dicing tape includes: a synthesis step of synthesizing an acrylic 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 acrylic copolymer, 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.

[0120] In the synthesis step, for example, an acrylic copolymer intermediate is synthesized by radically polymerizing a C8 to C12 alkyl (meth)acrylate monomer having 8 or more and 12 or less carbon atoms in the alkyl portion and a hydroxy group-containing (meth)acrylic monomer. Radical polymerization can be carried out by a common method. For example, the above-mentioned monomers are dissolved in a solvent, stirred under heating, and a polymerization initiator is added to synthesize an acrylic copolymer intermediate. In order to adjust the molecular weight of the acrylic copolymer, polymerization may be carried out in the presence of a chain transfer agent. Next, some of the hydroxyl groups in the hydroxyl group-containing (meth)acrylate units contained in the acrylic copolymer intermediate are bonded to the isocyanate groups of the isocyanate group-containing polymerizable monomer by a urethane reaction, whereby some of the hydroxyl group-containing (meth)acrylate units become polymerizable (meth)acrylate units containing a radically polymerizable carbon-carbon double bond. The urethane reaction can be carried out by a conventional method. For example, the acrylic copolymer intermediate and the 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 form a urethane bond with some of the hydroxy groups of the acrylic copolymer intermediate.

[0121] In the pressure-sensitive adhesive layer preparation step, for example, an acrylic 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, a solidification treatment, or the like to solidify the applied pressure-sensitive adhesive composition, thereby preparing the pressure-sensitive adhesive layer 22.

[0122] 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.

[0123] 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 acrylic copolymer, and also between the crosslinking agent and the surface portion of the base layer 21, an aging treatment process may be carried out for 48 hours in an environment of 50°C after the lamination process.

[0124] Through these steps, the dicing tape 20 can be manufactured.

[0125] <Process 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.

[0126] 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.

[0127] The dicing die bond film 1 manufactured as described above through the above-described steps is used, for example, as an auxiliary tool for manufacturing a semiconductor device (semiconductor integrated circuit). A method for manufacturing a semiconductor device (a method for using the dicing die bond film) will be described below.

[0128] <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.

[0129] The method for manufacturing a semiconductor device according to this embodiment includes the steps of: a cleaving step of cleaving the semiconductor wafer on which the circuit surface is formed into semiconductor chips (dies); and a pick-up step of peeling the die bond sheet attached to the adhesive layer of the above-mentioned dicing die bond film from the adhesive layer together with the semiconductor chip.

[0130] In the manufacturing method of the semiconductor device of this embodiment, the cleaving process 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 cleaving process; a backgrinding process in which the semiconductor wafer to which the backgrind tape has been attached is ground to reduce its thickness; a 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; an expanding process in which the dicing tape 20 is stretched to cleave the semiconductor wafer to produce semiconductor chips and widen the gap between adjacent semiconductor chips; and a 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.

[0131] 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).

[0132] Instead of the stealth dicing process, a half-cut process may be performed, which is a step in the so-called DBG (Dicing Before Grinding) process. In the half-cut process, a groove is formed in the semiconductor wafer to process the semiconductor wafer into semiconductor chips (dies) by a fracturing process, and then the semiconductor wafer is ground to reduce its thickness. Specifically, in the half-cut process, a semiconductor wafer with a circuit surface formed thereon is subjected to half-cut processing to split it into semiconductor chips (dies). More specifically, a wafer processing tape is attached to the surface of the semiconductor wafer opposite the circuit surface. With the wafer processing tape attached to the semiconductor wafer, grooves for dividing the semiconductor wafer are formed. A backgrind tape is attached to the surface with the grooves formed, while the wafer processing tape that was initially attached is peeled off.

[0133] 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.

[0134] 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 chip (die) to be fabricated in a subsequent cleaving process. For example, the half-cut semiconductor wafer W may be ground until it reaches a predetermined thickness so as not to be separated. If the grinding process is performed in this manner, the semiconductor wafer W will be cleaved into semiconductor chips and the die bond sheet 10 will also be cleaved in a subsequent expanding process (particularly a low-temperature expanding process). On the other hand, the grinding process may be performed until the half-cut semiconductor wafer W is separated. If the grinding process is performed in this manner, the die bond sheet 10 will be cleaved in a subsequent expanding process (particularly a low-temperature expanding process), for example, while widening the gap between adjacent semiconductor chips.

[0135] 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).

[0136] Before the expanding step, the die bond sheet 10 may be cleaved by, for example, irradiation with laser light. Specifically, when the semiconductor wafer W is individualized by the above-mentioned cutting process, the die bond sheet 10 that overlaps the semiconductor chips obtained by individualizing the semiconductor wafer but has not yet been cleaved may be cut by irradiation with laser light. Thereafter, the spacing between adjacent semiconductor chips may be widened by the expanding step.

[0137] In the expanding step, as shown in FIGS. 5A to 5C, the spacing between the semiconductor chips X produced by cleaving is increased. Specifically, a dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and then the dicing ring R is 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). When the above-described DBG process is carried out, a method of cleaving the die bond sheet 10 at a low temperature may be adopted in the expanding step, or a method of cutting the die bond sheet 10 with a laser may be adopted. When cutting the die bond sheet 10 with a laser, the expanding step may be carried out at a lower temperature after the die bond sheet 10 is cut.

[0138] In this embodiment, the dicing tape 20 is stretched in the planar direction by the expanding process. If the dicing tape 20 is not heated around the diced semiconductor chips, the central portion of the dicing tape 20 overlapping the diced semiconductor chips will shrink and return to its original shape. To prevent this shrinkage, the dicing tape 20 is heated around the diced semiconductor chips at a temperature of approximately 120°C. In other words, the portion of the dicing tape 20 that does not overlap the diced semiconductor chips and that extends along the periphery of the diced semiconductor chips is heated at a temperature of approximately 120°C. The heating process is performed using a heater S or the like that can move circumferentially along the periphery of the diced semiconductor chips, as shown in FIG. 7 . Therefore, some portions of the dicing tape 20 that are heated may be higher in temperature than others. As shown in Figure 7, for example, in the portion of the dicing tape 20 that is heat-treated, which is a strip-shaped portion that surrounds the outer periphery of the semiconductor chip group, the temperature may be higher in one longitudinal portion and lower in the other.

[0139] Before the pick-up step, for example, the adhesive layer 22 overlapping the base layer 21 is irradiated with ultraviolet light from the base layer 21 side, thereby subjecting the adhesive layer 22 to a curing treatment (curing treatment step).

[0140] 8, in the pick-up process, the semiconductor chip X with the die bond sheet 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.

[0141] In the die bonding process, the semiconductor chip X with the die bond sheet 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 10 attached thereto may be stacked multiple times.

[0142] 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 10 and promote the hardening of the die bond sheet 10.

[0143] 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).

[0144] 10, the semiconductor chip X and the die bond sheet 10 are sealed with a thermosetting resin M such as an 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.

[0145] 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).

[0146] In the above-described semiconductor device manufacturing method (method of using a dicing die bond film), in the expanding step (particularly the room-temperature expanding step), the dicing tape 20 is stretched with a strong force in the surface direction so as to expand its area. After the dicing tape 20 is stretched, a portion of the dicing tape 20 is shrunk by heat treatment at approximately 120°C. Specifically, the dicing tape 20 in the portion (periphery portion) along the periphery of the group of multiple semiconductor chips, which does not overlap with the multiple diced semiconductor chips, is shrunk by the heat treatment described above. Since the heat shrinkage rate is 6% or more, the portion (periphery portion) heated by the heat treatment described above is likely to shrink. Since the peripheral portion is likely to shrink, shrinkage of the dicing tape 20 in the portion (central portion) overlapping with the multiple diced semiconductor chips is suppressed. In other words, the portion (central portion) of the stretched dicing tape 20 overlapping with the multiple semiconductor chips can be suppressed from shrinking in the direction opposite to the stretching direction. Therefore, it is possible to prevent the gaps between the many diced semiconductor chips from becoming narrower. On the other hand, if the heat shrinkability of the dicing tape 20 at 120°C is not controlled, and the dicing tape 20 does not shrink much due to heat treatment, the central portion of the dicing tape 20 will tend to shrink relatively easily, narrowing the spacing between the many small semiconductor chips. This can make it difficult to create sufficient kerf spacing between the semiconductor chips after the expanding step. In the dicing die bond film of this embodiment, the thermal shrinkage rate of the dicing tape 20 at 120° C. is 6% or more, so that as described above, it is possible to provide a sufficient kerf between the semiconductor chips after the expanding step.

[0147] Furthermore, the heat treatment of the dicing tape 20 as described above is performed by moving a heater or the like along the periphery of the group of diced semiconductor chips, as shown in FIG. 7 . Specifically, two heaters or the like move halfway around the periphery of the group of diced semiconductor chips. In this heat treatment method, some parts are heated first and some are heated last. Therefore, a temperature difference occurs between the first and last heated parts. In other words, the temperature of the first heated part cools as the heater or the like moves away, and therefore becomes lower than the temperature of the last heated part when the heat treatment is completed. Generally, the higher the temperature, the lower the elastic modulus of a material. Therefore, the elastic modulus of a high-temperature part (for example, around 120°C) before cooling can be significantly lower than that of a cooled part. Therefore, the high-temperature part of the dicing tape 20, whose elastic modulus has been reduced by high temperature, may not necessarily be able to sufficiently suppress the shrinkage force of the dicing tape 20 in the direction opposite to the stretching direction. On the other hand, the cooled part of the dicing tape 20 has a high elastic modulus, so it can sufficiently suppress the shrinkage force. In this state, the dicing tape 20 tends to shrink unevenly in the area where it overlaps with the group of semiconductor chips, which may result in variations in the kerfs of the group of semiconductor chips that have once expanded. In contrast, in the dicing die bond film of this embodiment, the dicing tape 20 at 120° C. Tensile storageThe elastic modulus is 0.10 MPa or higher, and the elastic modulus is relatively high even at a high temperature of 120°C, so the shrinking force of the dicing tape 20 can be sufficiently suppressed. The temperature of 120°C is close to the temperature at which a portion of the stretched dicing tape 20 is heat-treated and shrunk in the expanding process. As described above, the heat treatment is performed by sequentially heating the portions to be heated along the periphery of the diced semiconductor chips using a heater or the like. Therefore, portions whose temperature increases as a result of heating and portions whose temperature decreases after heating are mixed. Even in such a situation, the dicing tape 20 of this embodiment has a relatively high elastic modulus at high-temperature portions (e.g., portions at 120°C), so the shrinking force of the dicing tape 20 can be sufficiently suppressed not only at low-temperature portions but also at high-temperature portions. Therefore, the shrinking force can be suppressed from varying depending on the portion in the center of the dicing tape 20 overlapping the semiconductor chips. Therefore, the kerf variation depending on the portion after the expanding process can be suppressed.

[0148] The dicing die bond film of this embodiment is as exemplified above, but the present invention is not limited to the dicing die bond film exemplified above. That is, various forms used in general dicing die bond films can be adopted within the range that does not impair the effects of the present invention.

[0149] The matters disclosed by this specification include the following. (1) A dicing tape having a base layer and a pressure-sensitive adhesive layer overlaid on the base layer, and a die bond sheet overlaid on the dicing tape, The dicing tape at 120°C Tensile storage The elastic modulus is 0.10 MPa or more, The dicing die bond film has a heat shrinkage rate of 6% or more at 120°C. (2) The dicing die bond film according to (1) above, wherein the base layer contains an ethylene-vinyl acetate copolymer resin and a polypropylene resin. (3) The dicing die bond film according to (1) or (2) above, wherein the base layer is composed of a plurality of layers. (4) The dicing die bond film according to (3) above, wherein the base layer is composed of three or more layers. (5) the substrate layer is composed of three layers, a first substrate layer, a second substrate layer, and a third substrate layer, stacked one on top of the other; A dicing die bond film as described in (4) above, wherein the first substrate layer and the third substrate layer arranged on both sides each contain a polypropylene resin, and the second substrate layer arranged between the first substrate layer and the third substrate layer contains an ethylene-vinyl acetate copolymer resin. (6) The dicing die bond film according to (5) above, wherein at least one of the first base material layer and the third base material layer further contains an antistatic agent. (7) The dicing die bond film according to (6) above, wherein the antistatic agent is at least one selected from the group consisting of polyolefin-polyethylene glycol copolymers, polyolefin-polyamide copolymers, polyethylene glycol-polyamide copolymers, polyethylene glycol-(meth)acrylate copolymers, polyethylene glycol-epichlorohydrin copolymers, ionomers, and mixtures of polymers and ionic compounds (e.g., metal salts such as lithium salts). (8) A dicing die bond film according to any one of (5) to (7) above, wherein the first substrate layer and the third substrate layer each independently have a thickness of 1 μm or more and 15 μm or less, and the second substrate layer has a thickness of 70 μm or more and 120 μm or less. (9) Of the surfaces of the layers constituting the base layer, the surface farthest from the pressure-sensitive adhesive layer has a surface resistivity of 1.00×10 9 [Ω / sq.] or more 1.00×1012 The dicing die bond film according to any one of (3) to (8) above, wherein the dielectric constant is [Ω / sq.] or less. (10) The dicing die bond film according to any one of (1) to (9) above, wherein the pressure-sensitive adhesive layer contains an acrylic copolymer, an isocyanate compound, and a polymerization initiator. (11) The die bond sheet is a dicing die bond film according to any one of (1) to (10) above, which comprises a crosslinkable group-containing acrylic polymer having a crosslinkable group in the molecule that undergoes a crosslinking reaction by heat curing treatment, a thermosetting resin, and a filler. [Example]

[0150] 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.

[0151] A dicing tape was produced as follows: The dicing tape was bonded to a die bond sheet to produce a dicing die bond film.

[0152] <Creating dicing tape> [Adhesive layer] (raw material monomer for acrylic copolymer) 2-Hydroxyethyl acrylate (HEA): 20 parts by weight 2-Ethylhexyl acrylate (2EHA): 100 parts by mass

[0153] The above raw materials were placed in a reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer. 0.2 parts by weight of azobisisobutyronitrile (AIBN) was used as a thermal polymerization initiator for a total of 100 parts by weight of monomers. Ethyl acetate was added as a reaction solvent so that the total monomer concentration reached a predetermined concentration (e.g., 35% by weight). The polymerization reaction was carried out in a nitrogen stream at 62°C for a predetermined time (e.g., 3 hours), and then at 75°C for a predetermined time (e.g., 4 hours), yielding an acrylic copolymer intermediate. In each example and comparative example, the monomer concentration during polymerization and the polymerization time are as shown in Table 2.

[0154] To the solution containing the acrylic copolymer intermediate prepared as described above, 2-methacryloyloxyethyl isocyanate (hereinafter also referred to as MOI) was added so that the amount was 80 mol% in terms of moles relative to the total amount of HEA. Furthermore, 0.03 mass% of dibutyltin dilaurate was added as a reaction catalyst relative to the amount of MOI added. Subsequently, an addition reaction (urethane reaction) was carried out in an air stream at 50°C for 12 hours to obtain an acrylic copolymer. Next, the following ingredients were added to 100 parts by mass of the acrylic copolymer to prepare a pressure-sensitive adhesive solution. Photopolymerization initiator: 2.5 parts by mass (Product name: Omnirad127D, manufactured by IGM) Polyisocyanate compound: 0.75 parts by mass (Product name: Takenate D-101E, manufactured by Mitsui Chemicals) Antioxidant: 0.01 parts by weight (Product name: Irganox1010, manufactured by BASF Japan) The adhesive solution prepared as described above was applied to the treated surface of a silicone-treated PET release liner and dried by heating at 120° C. for 2 minutes to form an adhesive layer with a thickness of 10 μm.

[0155] [Base material layer] Using the products shown below as raw materials, three-layer or two-layer laminated substrate layers, or a single-layer substrate layer were produced with the blending compositions shown in Tables 1 and 2. The composition of the single-layer substrate layer is shown in the column for the first substrate layer. (Polyolefin resin) PO-1: Product name "Wintek WXK1233" (Japan Polypropylene) Polyolefin resin (metallocene polypropylene resin) PO-2: Product name "Vistamaxx3980FL" (manufactured by ExxonMobil Chemical Company) Polyolefin resin (propylene elastomer resin, ethylene content 9%) PO-3: Product name "Zelas 5053YT13" (manufactured by Mitsubishi Chemical Corporation) Polyolefin resin (olefin thermoplastic elastomer resin) PO-4: Product name "Zelas ZT536" (Mitsubishi Chemical Corporation) Polyolefin resin (olefin thermoplastic elastomer resin) (ethylene vinyl acetate resin) EVA-1: Product name "EVAFLEX P1007" (manufactured by Mitsui Dow Polychemicals) Ethylene-vinyl acetate copolymer resin (containing 10% vinyl acetate by mass) EVA-2: Product name "Ultrasen 626" (manufactured by Tosoh Corporation) Ethylene-vinyl acetate copolymer resin (containing 15% vinyl acetate by mass) EVA-3: Product name "EVAFLEX V1030" (manufactured by Mitsui Dow Polychemicals) Ethylene-vinyl acetate copolymer resin (containing 10% vinyl acetate by mass) EVA-4: Ethylene-vinyl acetate copolymer resin (manufactured by Mitsui-Dow Polychemicals) (low density polyethylene resin) PE: Product name "Sumikasen F723-P" (manufactured by Sumitomo Chemical Co., Ltd.) (ionomer resin) IO: Mitsui Dow Polychemicals (Polyurethane resin) PU: BASF (antistatic agent) AS: Product name "Pelestat 230" (manufactured by Sanyo Chemical Industries, Ltd.) Polyolefin-polyethylene glycol copolymer

[0156] [Table 1]

[0157] [Table 2]

[0158] (Forming of base layer) The substrate layer was molded using an extrusion T-die molding machine. The extrusion temperature was 190°C. The two-layer type and three-layer laminate type substrate layers were integrated by co-extrusion molding from a T-die. After the integrated substrate layer (laminate) was sufficiently solidified, the substrate layer was wound into a roll and stored. The thickness of each layer constituting the base layer is as shown in Tables 1 and 2, respectively.

[0159] [Bonding of adhesive layer and base layer] Subsequently, the adhesive layer and the base layer prepared as described above were bonded together and stored at 50° C. for 24 hours to produce a dicing tape.

[0160] <Production of die bond sheet> Acrylic polymer: 100 parts by weight (Product name "PARACRON KG-8001", mass average molecular weight: 1,200,000, glass transition temperature Tg: 9℃, contains epoxy group, manufactured by Negami Kogyo Co., Ltd.) Phenolic resin: 3 parts by weight (Product name: MEHC-7851SS, solid at 23°C, manufactured by Meiwa Kasei Co., Ltd.) Silica filler: 10 parts by weight (Product name: SE2050-MCV, average particle size 500 nm, manufactured by Admatechs Co., Ltd.) The above raw materials were added to a predetermined amount of methyl ethyl ketone and mixed to prepare an adhesive composition solution with a total solids concentration of 12% by mass. Next, the adhesive composition was applied to the silicone release-treated surface of a PET release liner using an applicator to form a coating film. This coating film was then dried by heating at 130°C for 2 minutes, and a 10 μm thick die-bonding sheet was produced on the PET release liner.

[0161] (Examples 1 to 3, Comparative Examples 1 to 5) [Dicing die bond film manufacturing] The configurations of the base material layers of the die bond sheet are shown in Tables 1 and 2. The die bond sheet was punched into a circular shape with a diameter of 330 mm to produce a circular die bond sheet. At room temperature, a laminator was used to bond the circular die bond sheet and dicing tape together to produce a dicing die bond film.

[0162] <Measurement of dicing tape properties> The physical properties of the dicing tape of the dicing die bond film of each example and each comparative example were measured as follows.

[0163] [At 120℃ Tensile storage Elastic modulus] Dicing tape elastic modulus (tensile storage The details of the method for measuring the elastic modulus are as described above. The measurement results of each elastic modulus at 40°C and 120°C are shown in Table 3.

[0164] [Heat shrinkage rate at 120℃] The details of the method for measuring the heat shrinkage rate of the dicing tape at 120° C. are as described above. Table 3 shows the measurement results of the heat shrinkage rate.

[0165] Table 3 shows the composition and physical properties of the die bond sheet in each example and each comparative example.

[0166] [Table 3]

[0167] The performance of the dicing die bond film produced as described above was evaluated as follows.

[0168] <Performance evaluation (kerf distance between adjacent semiconductor chips)> (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 / 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 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). (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. Then, while maintaining the expanded state, the dicing tape in the area surrounding the outer edge of the wafer was thermally shrunk by a heater under conditions of a heat temperature of 250°C, a heat distance of 20 mm, and a rotation speed of 3° / sec. That is, by using the heat treatment method shown in Figure 7, the dicing tape in the area not overlapping with the group of multiple semiconductor chips was heat-treated, and the heat-treated area was thermally shrunk. After heat shrinkage, the spacing (kerf) between the die-bond sheet-attached chips was measured at multiple locations using a microscope. The kerf was determined by measuring the spacing at 10 random locations and calculating the arithmetic average of the measurements. A kerf (average value) of 15 μm or more was evaluated as "good," 50 μm or more as "particularly good," and less than 15 μm as "poor."

[0169] <Performance evaluation (Kerf variation suppression / Kerf uniformity)> After heat shrinking a portion of the dicing tape as described above, the spacing (kerf) between the die-bond sheet-attached chips was observed at multiple locations using a microscope. Specifically, the kerfs between multiple chips that had become rectangular due to cleavage were observed at the locations where the spacing (kerf) between the chips was measured as described above. More specifically, the kerfs between chips in groups of four adjacent chips in the directions in which the two mutually perpendicular sides of each chip extended (directions A and B) were observed. The uniformity of the kerf was evaluated based on whether the kerfs (dicing lines) extending in the directions A and B were linear. A dicing line that was linear in both directions A and B (appearing cross-shaped) was judged to be "good." On the other hand, a dicing line that was bent in either direction A or B was judged to be "poor."

[0170] As can be seen from the above evaluation results, the dicing die bond film of the example was able to both sufficiently space the kerfs between the semiconductor chips after the expansion process and suppress variation in the kerf depending on the location, compared to the dicing die bond film of the comparative example.

[0171] In the dicing die bond film of the embodiment, the dicing tape at 120°C Tensile storage The modulus of elasticity is 0.10 MPa or more, and the thermal shrinkage rate of the dicing tape at 120°C is 6% or more. By using the dicing die bond film of the embodiment having such a configuration when manufacturing a semiconductor device, the semiconductor device can be manufactured efficiently. In the manufacturing of a semiconductor device, in the expanding process, the dicing tape is stretched and the semiconductor wafer is diced. After the expanding process, for example, a heater or the like is moved in one direction along the periphery of the diced semiconductor chips, and the dicing tape around the periphery of the diced semiconductor chips is thermally shrunk by heating. By thermally shrinking the dicing tape around the periphery of the semiconductor chips in this manner, the force of the dicing tape shrinking in the direction opposite to the stretching direction can be weakened. The weakened shrinkage force of the dicing tape allows the spacing (kerf) between adjacent semiconductor chips, which had once expanded, to be maintained. In this case, since the thermal shrinkage rate of the dicing tape at 120°C is 6% or more as in the above embodiment, loosening of the peripheral portion of the dicing tape after the expanding process can be sufficiently suppressed. Therefore, it is believed that the central portion of the dicing tape overlapping the semiconductor chips can be prevented from shrinking and returning to its original shape, thereby enabling a sufficient kerf to be formed between the semiconductor chips. In addition, as in the above example, the dicing tape at 120°C Tensile storage By having an elastic modulus of 0.10 MPa or higher, the portion of the dicing tape that is heated includes a mixture of areas that are heated first and have a lower temperature, and areas that are heated last and have a higher temperature (for example, around 120°C). Even if there are temperature differences within the heat-treated portion of the dicing tape, the elastic modulus in the high-temperature portion is relatively high, so the variation in the force exerted when the dicing tape tries to shrink in the portion (center portion) overlapping with the large number of semiconductor chip groups can be suppressed. Therefore, it is believed that the variation in kerf depending on the portion of the semiconductor chip group was suppressed. [Industrial Applicability]

[0172] The dicing die bond film of the present invention is suitably used, for example, as an auxiliary tool when manufacturing a semiconductor device (semiconductor integrated circuit). [Explanation of symbols]

[0173] 1: Dicing die bond film, 10: Die bond sheet, 20: dicing tape, 21: Base material layer, 22: Adhesive layer.

Claims

1. A dicing tape having a base layer and a pressure-sensitive adhesive layer overlaid on the base layer, and a die bond sheet overlaid on the dicing tape, The dicing tape has a tensile storage modulus of 0.10 MPa or more at 120°C, A dicing die bond film, wherein when the dicing tape is in a long strip shape with a width of 30 mm, the thermal shrinkage rate of the dicing tape at 120°C over a length of 100 mm in the longitudinal direction is 6% or more.

2. The dicing die bond film according to claim 1, wherein the base layer contains an ethylene-vinyl acetate copolymer resin and a polypropylene resin.

3. The dicing die bond film according to claim 1 or 2, wherein the base layer is composed of a plurality of layers.

4. The dicing die bond film according to claim 3 , wherein the base layer is composed of three or more layers.

5. the substrate layer is composed of three layers, a first substrate layer, a second substrate layer, and a third substrate layer, stacked one on the other; The first base material layer and the third base material layer arranged on both sides each contain a polypropylene resin, and the second base material layer arranged between the first base material layer and the third base material layer contains an ethylene-vinyl acetate copolymer resin. The dicing die bond film according to claim 4.

6. The dicing die bond film according to claim 5 , wherein at least one of the first base material layer and the third base material layer further contains an antistatic agent.

7. The dicing die bond film according to claim 5 or 6, wherein the first substrate layer and the third substrate layer each independently have a thickness of 1 μm or more and 15 μm or less, and the second substrate layer has a thickness of 70 μm or more and 120 μm or less.

8. 8. The dicing die bond film according to claim 3, wherein the surface farthest from the pressure-sensitive adhesive layer among the surfaces of the plurality of layers constituting the base material layer has a surface resistivity of 1.00 × 10 [Ω / sq.] or more and 1.00 × 10 [Ω / sq.] or less.

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