Dicing / die-bonding integrated film and method for manufacturing same

Abstract

Disclosed is a dicing / die-bonding integrated film 10 comprising: a dicing film 5 including a base material film 3 and an adhesive layer 2 provided on the base material film 3; and an adhesive layer disposed on the adhesive layer 2 of the dicing film 5 and composed of a die bonding film 1. The loss tangent of the dicing film 5 at 0°C is 0.15 or less.

Description

Dicing and die bonding integrated film and its manufacturing method

[0001] The present disclosure relates to a dicing and die bonding integrated film and a method for manufacturing the same.

[0002] A semiconductor device is manufactured through the following steps: First, a dicing step is performed with an adhesive film for dicing attached to a wafer, followed by an expanding step, a pick-up step, a die bonding step, and so on.

[0003] In the manufacturing process of semiconductor devices, a dicing / die-bonding integrated film is sometimes used, which integrates a dicing film having a base film and an adhesive layer with a die-bonding film for bonding between the film and a substrate or another semiconductor chip. The dicing / die-bonding integrated film is used, for example, as follows: First, the die-bonding film (adhesive layer) side is attached to a wafer, and the wafer is diced while being fixed with a dicing ring. This separates the wafer into multiple chips. Next, the adhesive layer is irradiated with ultraviolet light to reduce the adhesive strength of the adhesive layer to the die-bonding film, and the chips are picked up from the adhesive layer together with the die-bonding film pieces resulting from the singulation of the die-bonding film. The semiconductor device is then manufactured by mounting the chip on a substrate or the like via the die-bonding film pieces. The laminate consisting of the chip obtained through the dicing process and the die-bonding film pieces attached thereto is called a chip with die-bonding film pieces attached thereto.

[0004] Conventionally, blade dicing, which involves cutting with a blade or the like, has been widely known as a method for dicing wafers and adhesive layers. In recent years, stealth dicing has become more common in line with the increasing integration of semiconductor packages and the thinning of wafers (see Patent Documents 1 and 2). Stealth dicing is a method in which a cutting line is formed inside an object to be processed using a laser, and then the wafer and die bonding film are cut along the cutting line to obtain chips with die bonding film pieces.

[0005] JP 2002-192370 A JP 2003-338467 A

[0006] In the manufacturing process of a semiconductor device, when a modified region is formed and divided by stealth dicing, expansion under cooling conditions (for example, 0°C or below) (hereinafter, sometimes referred to as "cooling expansion") is sometimes performed. However, when a conventional dicing / die-bonding integrated film is applied to cooling expansion, the die-bonding film may be difficult to separate during cooling expansion. If the die-bonding film is not easily separated, it becomes difficult to pick up the semiconductor chip with the die-bonding film piece attached, which may reduce the yield in the manufacturing of the semiconductor device.

[0007] A primary object of the present disclosure is to improve the cooling separation properties of a die bonding film in a predetermined method for manufacturing a semiconductor device.

[0008] The present disclosure includes [1] to [6]. [1] A dicing film including a base film and a pressure-sensitive adhesive layer provided on the base film, and an adhesive layer made of a die bonding film disposed on the pressure-sensitive adhesive layer of the dicing film, wherein the loss tangent of the dicing film at 0°C is 0.15 or less, and the loss tangent is such that: a measurement sample of the dicing film having a rectangular main surface with a short side of 5 mm and a long side of 8 mm is prepared;

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[0099] [[4] A method for measuring the loss tangent of a dicing film comprising a base film and a pressure-sensitive adhesive layer provided on the base film, the loss tangent being 0.15 or less at 0°C, and a step of bonding a die bonding film to the pressure-sensitive adhesive layer of the dicing film, the loss tangent being 0.15 or less at 0°C. A method for measuring the loss tangent of a dicing film comprising a viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) having a solid shearing jig with a first plate-like member and a pair of second plate-like members, the method comprising: a method for manufacturing a dicing-die bonding integrated film, wherein the loss tangent is a value determined by a method including: placing the measurement sample so that it sandwiches the first plate-like member, and fixing the measurement sample to the solid shearing jig by clamping the measurement sample in a thickness direction with each of the pair of second plate-like members under conditions of a clamping pressure of 9 cN·m with a torque wrench; and determining the loss tangent by shear mode dynamic viscoelasticity measurement using the solid shearing jig to which the measurement sample is fixed under conditions of a measurement frequency of 10 Hz, a distortion amount of 1% relative to the total thickness of the dicing film, and a heating rate of 2°C / min.

[0009] According to the present disclosure, it is possible to improve the cooling separation properties of a die bonding film in a predetermined method for manufacturing a semiconductor device.

[0010] FIG. 1 is a schematic cross-sectional view showing one embodiment of a dicing film. FIG. 2 is a schematic view for explaining a method for measuring the loss tangent of a dicing film at 0° C. FIG. 3 is a schematic cross-sectional view showing one embodiment of a dicing / die bonding integrated film. FIG. 4 is a cross-sectional view showing a method for manufacturing a semiconductor device, with FIGS. 4(a), 4(b), and 4(c) being cross-sectional views showing each step. FIG. 5 is a cross-sectional view showing a method for manufacturing a semiconductor device, with FIGS. 5(a) and 5(b) being cross-sectional views showing each step.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as appropriate. However, the present disclosure is not limited to the following embodiments. In the following embodiments, components (including steps, etc.) are not essential unless specifically stated. The sizes of the components in each figure are conceptual, and the relative size relationships between the components are not limited to those shown in each figure.

[0012] The same applies to the numerical values ​​and ranges in this specification, and do not limit the present disclosure. In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples.

[0013] In this specification, "(meth)acrylate" means at least one of an acrylate and the corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl." "A or B" may contain either A or B, or may contain both. Unless otherwise specified, the materials exemplified below may be used alone or in combination of two or more. When multiple substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the multiple substances present in the composition, unless otherwise specified.

[0014] [Dicing Film] Fig. 1 is a schematic cross-sectional view showing one embodiment of a dicing film (dicing tape). The dicing film 5 shown in Fig. 1 comprises a base film 3 and a pressure-sensitive adhesive layer 2 provided on the base film 3. The base film 3 has, for example, a rectangular main surface. The main surface of the pressure-sensitive adhesive layer 2 may be a surface of the same size as the main surface of the die bonding film.

[0015] <Loss tangent (tan δ)> The loss tangent of the dicing film 5 at 0°C is 0.15 or less. The loss tangent is the ratio of the loss modulus to the storage modulus. The loss tangent is measured using a dynamic viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) equipped with a solid shear jig.

[0016] 2 is a schematic diagram illustrating a method for measuring the loss tangent. Two measurement samples 5A and 5B each having a pressure-sensitive adhesive layer 2 and a base film 3 are fixed to a solid shearing jig 50. The solid shearing jig 50 includes a first plate-like member 51 and a pair of second plate-like members 52a and 52b that can fix the measurement samples 5A and 5B by clamping them in the thickness directions d2 and d3 of the measurement samples 5A and 5B and can vibrate in the direction d1. The first plate-like member 51 and the second plate-like members 52a and 52b may each be a plate-like member made of stainless steel (SUS). The first plate-like member is fixed to the dynamic viscoelasticity measuring device, and the measurement samples 5A and 5B are fixed to the solid shearing jig 50 by the second plate-like members 52a and 52b. By vibrating the measurement samples 5A and 5B in the direction indicated by direction d1, stress is applied to the measurement samples 5A and 5B in the shear direction (direction d1).

[0017] The measurement samples 5A and 5B are arranged to sandwich the first plate-like member 51, with the main surface of the pressure-sensitive adhesive layer 2 in contact with the first plate-like member 51. The measurement samples 5A and 5B are arranged with the main surface facing the base film 3 in contact with the second plate-like members 52a and 52b, respectively. The measurement samples 5A and 5B are fixed to the solid shearing jig 50 by being clamped in directions d2 and d3 by the pair of second plate-like members 52a and 52b. The main surface of the first plate-like member 51 in contact with the pressure-sensitive adhesive layer 2 may be the same or approximately the same size as the main surface of the pressure-sensitive adhesive layer 2 of the measurement samples 5A and 5B. The main surfaces of the second plate-like members 52a and 52b in contact with the base film 3 may be the same or approximately the same size as the main surface of the base film 3 of the measurement samples 5A and 5B.

[0018] A dicing film 5 to be measured having a rectangular main surface with a short side of 5 mm and a long side of 8 mm is used as the measurement samples 5A and 5B. The measurement samples 5A and 5B are samples made from the same dicing film to be measured, and are made by cutting the dicing film 5 to be measured as necessary.

[0019] The measurement samples 5A and 5B are fixed to the solid shearing jig 50 with the MD direction of the base film 3 as the short side and oriented in the same direction as the vibration direction d1 of the solid shearing jig 50. The measurement samples 5A and 5B are fixed to the solid shearing jig 50 with the TD direction of the base film 3 as the long side and oriented perpendicular to the vibration direction d1 of the solid shearing jig 50. The MD direction (machine direction) is the direction parallel to the longitudinal direction (flow direction) of the raw web from which the base film 3 is obtained. The TD direction (transverse direction) is the direction perpendicular to the MD direction (vertical direction).

[0020] The measurement samples 5A and 5B are fixed to the solid shearing jig by clamping them in the thickness directions d2 and d3 with a pair of second plate-like members 52a and 52b under the condition that the clamping pressure is a torque wrench of 9 cN·m.

[0021] Measurements using a dynamic viscoelasticity measuring device are performed under conditions of a measurement frequency of 10 Hz, a strain amount of 1% relative to the total thickness of the dicing film, and a temperature rise rate of 2°C / min. The measurement temperature range may be -20°C to 60°C. The loss tangent is determined by shear mode dynamic viscoelasticity measurement using a solid shearing jig 50 to which measurement samples 5A and 5B are fixed. The strain amount is a set value for the dynamic viscoelasticity measurement.

[0022] The loss tangent at 0°C is 0.15 or less. When the loss tangent at 0°C is 0.15 or less, the separability by cooling and expanding is improved. The inventors speculate that when the loss tangent is 0.15 or less, the loss of breaking stress by the dicing film during cooling and expanding is sufficiently small, and as a result, the stress transmitted to the die bonding film is strengthened, thereby improving the separability in the cooling and expanding step, but the mechanism is not limited to this.

[0023] The loss tangent at 0°C may be 0.15 or less, 0.14 or less, 0.13 or less, 0.12 or less, 0.11 or less, 0.10 or less, 0.08 or less, 0.06 or less, or 0.04 or less, since this makes it easier to obtain a dicing-die-bonding integrated film that is excellent in separability by cooling expansion. The loss tangent may be 0.01 or more, or 0.02 or more.

[0024] The loss tangent at 0°C can be controlled to be within the above-mentioned numerical range, for example, by adjusting the composition of the adhesive constituting the adhesive layer (e.g., adhesive composition, amount of crosslinking agent used, type and amount of initiator used, etc.).

[0025] The thickness of the dicing film 5 (the total thickness of the base film 3 and the pressure-sensitive adhesive layer 2) may be 60 to 150 μm or 70 to 130 μm from the viewpoints of economy and film handling.

[0026] <Adhesive Layer> The adhesive layer 2 may be a layer formed of an adhesive commonly used in dicing films. The adhesive constituting the adhesive layer 2 may be an ultraviolet-curable adhesive or a non-ultraviolet-curable adhesive. The ultraviolet-curable adhesive is an adhesive whose adhesiveness decreases when irradiated with ultraviolet light. By using an ultraviolet-curable adhesive, for example, the adhesive strength of the adhesive layer 2 can be decreased by ultraviolet light irradiation before picking up the semiconductor chip to which the die-bonding film piece is attached.

[0027] The ultraviolet-curable adhesive may contain, for example, an acrylic resin having a (meth)acryloyl group. The acrylic resin may contain, for example, a hydroxyl group. The acrylic resin is a polymer containing a (meth)acrylic acid ester as a monomer unit. The ultraviolet-curable adhesive may further contain other components such as a photopolymerization initiator and a crosslinking agent (for example, a polyisocyanate compound) as necessary. The crosslinking agent is a compound having a reactive group that reacts with the acrylic resin. Examples of the crosslinking agent include polyisocyanate compounds.

[0028] The thickness of the pressure-sensitive adhesive layer 2 may be 20 μm or less, 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, 10 μm or less, 8 μm or less, 6 μm or less, 4 μm or less, or 2 μm or less, since this makes it easier to obtain a dicing / die-bonding integrated film that has excellent separability by cooling and expanding. The thickness of the pressure-sensitive adhesive layer 2 may be, for example, 1 μm or more, 3 μm or more, or 5 μm or more, from the viewpoints of adhesiveness during cooling and expanding and adhesion to the dicing ring. The thickness of the pressure-sensitive adhesive layer 2 may be, for example, 1 to 10 μm.

[0029] The ratio of the thickness (unit: μm) of the pressure-sensitive adhesive layer 2 to the thickness (unit: μm) of the base film 3 may be less than 1, ½ or less, ⅓ or less, ¼ or less, ⅙ or less, ⅛ or less, ⅛ or less, ⅙ or less, ⅙ or less, or 1 / 10 or less, or 1 / 15 or less. The ratio of the thickness (unit: μm) of the pressure-sensitive adhesive layer 2 to the thickness (unit: μm) of the base film 3 may be 1 / 150 or more, 1 / 125 or more, 1 / 100 or more, 1 / 75 or more, or 1 / 50 or more.

[0030] The thickness (unit: μm) of the adhesive layer 2 relative to the thickness (unit: μm) of the dicing film 5 may be less than 1, 1 / 2 or less, 1 / 4 or less, 1 / 6 or less, 1 / 8 or less, 1 / 10 or less, or 1 / 15 or less, or may be 1 / 100 or more, 1 / 75 or more, or 1 / 50 or more.

[0031] <Base Film> Resins constituting the base film 3 include homopolymers of olefins such as ethylene, propylene, butene, hexene, methylpentene, 4-methyl-1-pentene, and vinyl acetate, and copolymers thereof; polyesters such as polyethylene terephthalate and polyethylene naphthalate; ethylene copolymers such as ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester copolymer, and ethylene-(meth)acrylic acid-(meth)acrylic acid ester copolymer; and copolymers containing an olefin such as ethylene and (meth)acrylic acid, in which the acid moiety is not included. Examples of suitable materials include ionomer resins having an ionic crosslinking structure formed by salt formation between the polymer and metal ions (sodium ions, zinc ions, etc.); engineering plastics such as polycarbonate, polyamide, polyimide, polyether ether ketone, polyetherimide, wholly aromatic polyamide, and polyphenyl sulfide; aramid (paper); glass; glass cloth; fluorine-based resins; chlorine-based resins such as polyvinyl chloride and polyvinylidene chloride; cellulose-based resins; silicone-based resins; and mixtures of these with plasticizers, or cured products crosslinked by electron beam irradiation. The substrate film may be composed of a single resin or a mixed resin containing two or more resins. The substrate film may also be a laminate film having a laminate structure in which two or more films are laminated. The surface of the substrate film may be subjected to a surface roughening treatment such as a matte treatment or a corona treatment in order to control adhesion to the pressure-sensitive adhesive layer 2. The substrate film 3 may be a substrate film containing at least one resin selected from the group consisting of polyester, ethylene copolymer, ionomer resin, and engineering plastic.

[0032] The substrate film 3 can be produced by film formation using a conventionally known method. For example, the resin composition obtained by melt-kneading the resin raw material of the substrate with additives such as an antistatic agent, if necessary, can be processed into a film using various molding methods such as T-die casting, T-die nip molding, inflation molding, extrusion lamination, and calendar molding. Furthermore, when the substrate film has a laminate structure, each layer can be separately formed by means of calendar molding, extrusion, inflation molding, etc., and then laminated by means of thermal lamination or adhesive bonding to produce a laminate structure. The adhesive can be an adhesive commonly used in producing a laminate structure. Alternatively, the resin compositions of each layer can be simultaneously extruded using a coextrusion lamination method to produce a laminate structure. Furthermore, the surface of the substrate film opposite to the surface that contacts the pressure-sensitive adhesive layer may be embossed with a shiborol or the like to stabilize the winding during production of the substrate film 3 and prevent blocking after film formation.

[0033] The thickness of the base film 3 may be 20 μm or more, 30 μm or more, 40 μm or more, 50 μm or more, 60 μm or more, 70 μm or more, or 80 μm or more, because this makes it easier to obtain a dicing / die bonding integrated film that has excellent separability by cooling and expanding. The thickness of the base film 3 may be 200 μm or less, 150 μm or less, 130 μm or less, 110 μm or less, 100 μm or less, or 90 μm or less, because this is economically advantageous. The thickness of the base film 3 may be, for example, 30 to 150 μm, or 30 to 90 μm.

[0034] The shape of the base film 3 may have a rectangular main surface, but is not limited thereto. The base film 3 may be a long film, and for example, a plurality of pressure-sensitive adhesive layers 2 may be disposed on a single long base film 3.

[0035] <Method for Manufacturing Dicing Film> The dicing film 5 can be manufactured by a method including a step of selecting a dicing film having a loss tangent at 0° C. of 0.15 or less (selection step) as described above, for example.

[0036] 3 is a schematic cross-sectional view showing one embodiment of a dicing and die bonding integrated film including the above-mentioned dicing film. The dicing and die bonding integrated film 10 includes a die bonding film 1 (hereinafter sometimes referred to as an "adhesive layer") and a dicing film 5 having a pressure-sensitive adhesive layer 2 bonded to the die bonding film 1.

[0037] The die bonding film 1 is an adhesive film for bonding a semiconductor chip to a substrate or another semiconductor chip, and is also called a die attach film (DAF). The die bonding film 1 has, for example, a circular main surface that covers the entire main surface of a semiconductor wafer.

[0038] The thickness of the die bonding film 1 (adhesive layer) may be, for example, 150 μm or less, 120 μm or less, 100 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 25 μm or less, or 20 μm or less, or may be 3 μm or more, 5 μm or more, 7 μm or more, or 10 μm or more.

[0039] The die bonding film 1 may be a film formed from an adhesive that is commonly used for bonding semiconductor chips. The die bonding film 1 may be a thermosetting adhesive. The thermosetting adhesive that constitutes the die bonding film 1 contains, for example, a thermosetting component and a high-molecular-weight resin component (elastomer).

[0040] The thermosetting component is a compound (resin) having a reactive group that forms a crosslinked structure by self-polymerization and / or reaction with a curing agent. The thermosetting component may contain, for example, an epoxy resin, or may contain, in addition to the epoxy resin, a phenolic resin that acts as a curing agent for the epoxy resin. The content of the thermosetting component may be 5 to 250 parts by mass relative to 100 parts by mass of the total amount of the die bonding film.

[0041] The high-molecular-weight resin component (elastomer) may contain, for example, at least one resin selected from the group consisting of acrylic rubber, polyimide, and phenoxy resin, or may contain acrylic rubber. The high-molecular-weight resin component may have a reactive group such as an epoxy group. The weight-average molecular weight (standard polystyrene equivalent value measured by GPC method) of the high-molecular-weight resin component may be 100,000 to 3,000,000. The content of the high-molecular-weight resin component may be 30 to 80 parts by mass relative to 100 parts by mass of the total amount of the die bonding film.

[0042] The thermosetting adhesive may contain other components as needed, such as a curing accelerator that accelerates the reaction between the epoxy resin and the phenolic resin, a coupling agent (e.g., a silane coupling agent), and an inorganic filler (e.g., silica).

[0043] The integrated dicing / die bonding film can be suitably used in a method for manufacturing a semiconductor device that includes a step of expanding the dicing film under cooled conditions (e.g., below 0°C) to separate the die bonding film and produce semiconductor chips with die bonding film pieces.

[0044] <Method for Manufacturing Dicing and Die Bonding Integrated Film> The dicing and die bonding integrated film 10 can be manufactured by, for example, a method including a step of bonding the die bonding film and the pressure-sensitive adhesive layer 2 of the dicing film 5 together.

[0045] 4 and 5 are cross-sectional views schematically illustrating a method for manufacturing a semiconductor device. The method for manufacturing a semiconductor device includes the steps of: (A) preparing a laminate 40 including a dicing film 5 having a base film 3 and an adhesive layer 2 provided on the base film 3, and a die bonding film 1 provided on the adhesive layer 2, and the laminate 40 including a plurality of semiconductor chips C formed by dividing a semiconductor wafer and provided on the die bonding film 1 of the dicing and die bonding integrated film 10; and (B) expanding the dicing film 5 of the laminate 40 under cooling conditions to divide the die bonding film 1, thereby producing a semiconductor chip 30 with die bonding film pieces, the semiconductor chips C, and die bonding film pieces 1a formed by dividing the die bonding film 1. The method for manufacturing a semiconductor device may further include (C) a step of picking up the semiconductor chip 30 with the die bonding film piece from the adhesive layer 2, and (D) a step of mounting the picked-up semiconductor chip 30 with the die bonding film piece on a substrate or another semiconductor chip.

[0046] The semiconductor chips C are formed by dividing a semiconductor wafer. The semiconductor wafer may be a silicon wafer, and the semiconductor chips C may be silicon chips. The semiconductor chips C have a main surface F1 and a main surface F2. For example, the main surface F1 may be a circuit surface (front surface) and the main surface F2 may be a back surface opposite the circuit surface.

[0047] The thickness of the semiconductor wafer may be, for example, 8 inches or 12 inches.

[0048] The method for dicing the semiconductor wafer may be a stealth dicing method such as the SDBG (Stealth Dicing Before Grinding) method, or a half-cut dicing method such as the DBG (Dicing Before Grinding) method.

[0049] The stealth dicing method may be a method including, for example, a step of attaching a protective tape (backgrind tape) to the circuit surface of a semiconductor wafer, a step of forming a modified region inside the semiconductor wafer by irradiating it with laser light, and a step of grinding the semiconductor wafer from the back side and splitting the semiconductor wafer using the modified region as the splitting starting point.

[0050] The half-cut dicing method may be a method including, for example, a step of forming a groove on the surface of a semiconductor wafer with a dicing blade, a step of attaching a protective tape (back-grinding tape) to the circuit surface of the semiconductor wafer, and a step of grinding the semiconductor wafer from the back side down to the groove.

[0051] By using such a method for dicing a semiconductor wafer, a laminate 20 can be obtained, which includes a protective tape 7 (backgrind tape) and a plurality of semiconductor chips C provided on the protective tape 7 (see FIG. 4( a)). In the laminate 20, the semiconductor chips C are provided on the protective tape 7.

[0052] The thickness of the semiconductor chip C is smaller than that of the semiconductor wafer, and may be, for example, 10 to 200 μm. The thickness of the semiconductor chip C may be 15 μm or more, or 20 μm or more, or may be 150 μm or less, 100 μm or less, or 50 μm or less.

[0053] Next, the die bonding film 1 of the dicing and die bonding integrated film 10 is attached to the semiconductor chip C under heating conditions, with the die bonding film 1 in contact with the main surface F2 of the semiconductor chip C (see FIG. 4( a)). The temperature of the heating conditions may be, for example, 40 to 80°C. This results in a laminate 40 comprising the dicing and die bonding integrated film 10 and a plurality of semiconductor chips C formed by dicing a semiconductor wafer and disposed on the die bonding film 1 of the dicing and die bonding integrated film 10. At the same time that the die bonding film 1 is attached to the semiconductor chip C, a dicing ring DR is attached to the main surface 2b of the pressure-sensitive adhesive layer 2 facing the die bonding film 1 so as to surround the plurality of semiconductor chips C (see FIG. 4( b)). At the time of attachment to the semiconductor chip C, the laminate 40 may be provided with a dicing ring DR on the main surface 2b of the pressure-sensitive adhesive layer 2 facing the die bonding film 1. The protective tape 7 is peeled off from the semiconductor chip C at an appropriate timing.

[0054] Next, under cooling conditions, the region of the dicing film 5 inside the dicing ring DR is pushed up by the ring Ra, thereby expanding (stretching) the dicing film 5 (see FIG. 4(c)). The temperature of the cooling conditions may be, for example, −15 to 0° C. By expanding the dicing film 5, the die bonding film 1 is divided. By this division, a semiconductor chip 30 with a die bonding film piece is formed on the pressure-sensitive adhesive layer 2, the semiconductor chip C and die bonding film pieces 1a obtained by dividing the die bonding film 1.

[0055] After the ring Ra is lowered, the area of ​​the dicing film 5 between the dicing ring DR and the semiconductor chips 30 with die bonding film pieces is heated by a heater H (see FIG. 5(a)). Due to thermal contraction of the dicing film 5 in the heated area, the kerf width between the semiconductor chips 30 with die bonding film pieces tends to further increase.

[0056] When the adhesive layer 2 is a layer formed of an ultraviolet-curable adhesive, ultraviolet irradiation can reduce the adhesive strength of the adhesive layer 2. After the adhesive strength of the adhesive layer 2 has been reduced, the individual semiconductor chips 30 with die-bonding film pieces that have been pushed up by the push-up jig 42 are picked up by a suction collet 44 (see FIG. 5(b)).

[0057] The picked-up semiconductor chip 30 with the die bonding film piece attached is mounted on a substrate or another semiconductor chip. By stacking multiple semiconductor chips, for example, a 3D NAND flash memory can be manufactured.

[0058] The present disclosure will be specifically described below based on examples, but the present disclosure is not limited to these examples.

[0059] Example 1 1-1. Preparation of Pressure-Sensitive Adhesive Layer (Production Example A-1) Acrylic polymer 1, a copolymer of the following monomers, was prepared. The weight-average molecular weight (Mw) of acrylic polymer 1 was 910,000, the number-average molecular weight (Mn) was 140,000, and Mw / Mn was 6.5. The hydroxyl value of acrylic polymer 1 was 2.5 mgKOH / g. Butyl acrylate: 88.1 parts by mass 2-hydroxyethyl methacrylate: 0.6 parts by mass Acrylonitrile: 11.2 parts by mass

[0060] To 100 parts by mass of acrylic polymer 1 in terms of solid content, 2.2 parts by mass of Coronate L38ET (manufactured by Tosoh Corporation, TMP adduct of tolylene diisocyanate, Nv 37.5%, TDI adduct trifunctional NCO% 6.6%) as a crosslinking agent was blended, and the mixture was diluted with methyl ethyl ketone (MEK) and stirred to prepare PSA solution A-1.

[0061] The adhesive solution A-1 was applied to a polyethylene terephthalate film (thickness: 38 μm) having one surface subjected to a release treatment so that the thickness after drying would be 10 μm, and the applied solution was dried at 80°C for 3 minutes to form an adhesive layer of Production Example A-1 on the polyethylene terephthalate film.

[0062] 1-2. Preparation of base film (Production Example B-1) A ternary copolymer consisting of ethylene / methacrylic acid / 2-methyl-propyl acrylate in a mass ratio of 80 / 10 / 10, containing Zn ２＋ Degree of neutralization by ions: 60 mol%, melting point: 86°C, MFR: 1 g / 10 min (190°C / 2.16 kg load), density: 0.96 g / cm ３ The resin was formed into a film having a thickness of 90 μm and used as the substrate film of Production Example B-1.

[0063] 1-3. Preparation of dicing film A base film (Production Example B-1) having one side subjected to corona discharge treatment was bonded to the pressure-sensitive adhesive layer of Production Example A-1. The bonded sample was aged in a thermostatic chamber at 23°C for 96 hours to prepare a dicing film.

[0064] 1-4. Preparation of Adhesive Layer (Production Example C-1) 100 parts by weight of HTR-860P-3 (trade name, manufactured by Nagase ChemteX Corporation, glycidyl group-containing acrylic rubber, molecular weight 1,000,000, Tg -7°C), 20 parts by weight of YDCN-700-10 (trade name, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., o-cresol novolac epoxy resin, epoxy equivalent 210), 17 parts by weight of Milex XLC-LL (trade name, manufactured by Mitsui Chemicals, Inc., phenol aralkyl resin), 1-(2-cyanoethyl)- 0.04 parts by weight of 2-phenylimidazole (2PZ-CN), 12 parts by weight of Aerosil R972 (trade name, manufactured by Nippon Aerosil Co., Ltd., silica, average particle size 0.016 μm), 0.6 parts by weight of A-189 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-mercaptopropyltrimethoxysilane), and 1.7 parts by weight of A-1170 (trade name, manufactured by Nippon Unicar Co., Ltd., γ-ureidopropyltriethoxysilane) were added and degassed under vacuum. This adhesive varnish was applied to a 75 μm thick surface-release-treated polyethylene terephthalate (manufactured by Teijin DuPont Films Co., Ltd., Teijin Tetron film: A-31) to obtain a 20 μm thick adhesive layer (die bonding film).

[0065] 1-5. Preparation of dicing and die bonding integrated film (Example 1) The adhesive layer (die bonding film) and the dicing film were attached together so that the adhesive layer of the die bonding film and the pressure-sensitive adhesive layer of the dicing film were in contact with each other, thereby obtaining the dicing and die bonding integrated film of Example 1.

[0066] Example 2 2-1. Preparation of Pressure-Sensitive Adhesive Layer (Production Example A-2) Acrylic polymer 2, a copolymer of the following monomers, was prepared. The weight-average molecular weight (Mw) of acrylic polymer 2 was 610,000, the number-average molecular weight (Mn) was 140,000, and Mw / Mn was 4.4. The hydroxyl value of acrylic polymer 2 was 19.5 mgKOH / g. Butyl acrylate: 71.2 parts by mass 2-hydroxyethyl methacrylate: 4.8 parts by mass Acrylonitrile: 24.0 parts by mass

[0067] 70 parts by mass, calculated as solids, of acrylic polymer 1, 30 parts by mass, calculated as solids, of acrylic polymer 2, and 2.2 parts by mass, calculated as solids, of Coronate L38ET (manufactured by Tosoh Corporation, TMP adduct of tolylene diisocyanate, Nv 37.5%, TDI adduct trifunctional NCO% 6.6%) as a crosslinking agent were blended, diluted with methyl ethyl ketone (MEK), and stirred to prepare PSA solution A-2. The PSA layer of PSA solution A-2 was produced in the same manner as in PSA solution A-1, except that PSA solution A-2 was used instead of PSA solution A-1.

[0068] 2-2. Preparation of dicing and die bonding integrated film (Example 2) A dicing and die bonding integrated film of Example 2 was prepared in the same manner as in Example 1, except that the pressure-sensitive adhesive layer of Production Example A-2 was used as the pressure-sensitive adhesive layer.

[0069] Comparative Example 1 3-1. Preparation of Pressure-Sensitive Adhesive Layer (Production Example A-3) 2-ethylhexyl acrylate (EHA), 2-hydroxyethyl acrylate (HEA), and methyl methacrylate (MMA) were prepared as copolymerizable monomer components. These copolymerizable monomer components were mixed to a copolymerization ratio of EHA / HEA / MMA = 78 parts by weight / 21 parts by weight / 1 part by weight, and an acrylic copolymer was obtained by solution radical polymerization using ethyl acetate as the solvent and 0.08 parts by weight of azobisisobutyronitrile (AIBN) as the initiator. This acrylic copolymer was reacted with 0.05 parts by weight of hydroquinone monomethyl ether as a polymerization inhibitor and 16 parts by weight of 2-methacryloyloxyethyl isocyanate (trade name: Karenz MOI, molecular weight: 155.15) to synthesize a UV-curable pressure-sensitive adhesive having a carbon-carbon double bond. The weight-average molecular weight of the obtained UV-curable pressure-sensitive adhesive was 350,000. The hydroxyl value and acid value of the ultraviolet-curable adhesive were 37.6 mg KOH / g and 6.5 mg KOH / g, respectively. 100 parts by mass (solid content equivalent) of the obtained ultraviolet-curable adhesive, 1.0 part by mass of an α-hydroxyalkylphenone-based photopolymerization initiator (trade name: Omnirad 184) manufactured by IGM Resins B.V., 0.2 parts by mass of an acylphosphine oxide-based photopolymerization initiator (trade name: Omnirad 819) manufactured by IGM Resins B.V., and 2.07 parts by mass (solid content equivalent) of a TDI-based polyisocyanate-based crosslinking agent (trade name: Coronate L-45E) manufactured by Tosoh Corporation were blended, diluted with ethyl acetate, and stirred to prepare adhesive solution A-3. An adhesive layer of Production Example A-3 was prepared in the same manner as in Production Example A-1, except that adhesive solution A-3 was used instead of adhesive solution A-1.

[0070] 3-2. Preparation of dicing and die bonding integrated film (Comparative Example 1) A dicing and die bonding integrated film of Comparative Example 1 was prepared in the same manner as in Example 1, except that the pressure-sensitive adhesive layer of Production Example A-3 was used as the pressure-sensitive adhesive layer.

[0071] Comparative Example 2 4-1. Preparation of Pressure-Sensitive Adhesive Layer (Production Example A-4) 100 parts by mass, converted to solids, of the UV-curable pressure-sensitive adhesive prepared in Production Example A-3, 1.0 part by mass of an α-hydroxyalkylphenone photopolymerization initiator (trade name: Omnirad 184) manufactured by IGM Resins B.V., 0.2 part by mass of an acylphosphine oxide photopolymerization initiator (trade name: Omnirad 819) manufactured by IGM Resins B.V., and 4.14 parts by mass, converted to solids, of a TDI-based polyisocyanate crosslinking agent (trade name: Coronate L-45E) manufactured by Tosoh Corporation were blended, diluted with ethyl acetate, and stirred to prepare a pressure-sensitive adhesive solution A-4. An adhesive layer of Production Example A-4 was prepared in the same manner as in Production Example A-1, except that adhesive solution A-4 was used instead of adhesive solution A-1.

[0072] 4-2. Preparation of dicing and die bonding integrated film (Comparative Example 2) A dicing and die bonding integrated film of Comparative Example 1 was prepared in the same manner as in Example 1, except that the pressure-sensitive adhesive layer of Production Example A-4 was used as the pressure-sensitive adhesive layer.

[0073] Examples 3 to 5 5-1. Preparation of Pressure-Sensitive Adhesive Layer (Production Example A-5) A UV-curable pressure-sensitive adhesive was synthesized in the same manner as the UV-curable pressure-sensitive adhesive in Comparative Example 1, except that the copolymerization ratio of EHA / HEA / MMA was 78 parts by mass / 21 parts by mass / 1 part by mass and 19 parts by mass of 2-methacryloyloxyethyl isocyanate (trade name: Karenz MOI, molecular weight: 155.15) was reacted. The weight-average molecular weight of the obtained UV-curable pressure-sensitive adhesive was 350,000. The hydroxyl value and acid value of the obtained UV-curable pressure-sensitive adhesive were 27.5 mg KOH / g and 6.5 mg KOH / g, respectively. The pressure-sensitive adhesive layer of Production Example A-5 was prepared in the same manner as Production Example A-1, except that the obtained UV-curable pressure-sensitive adhesive was used and the thickness of the pressure-sensitive adhesive layer was changed to the thickness shown in Table 2.

[0074] 5-2. Preparation of dicing and die bonding integrated films (Examples 3 to 5) Dicing and die bonding integrated films of Examples 3 to 5 were prepared in the same manner as in Example 1, except that the pressure-sensitive adhesive layer of Production Example A-5 was used as the pressure-sensitive adhesive layer and the thickness of the adhesive layer of Production Example C-1 was changed to 7 μm.

[0075] 6. Evaluation <Measurement of hydroxyl value and acid value> The hydroxyl value was measured in accordance with the method described in JIS K0070: 1992. The acid value was measured in accordance with the method described in JIS K2501: 2003.

[0076] <Measurement of Weight Average Molecular Weight and Number Average Molecular Weight> The weight average molecular weight and number average molecular weight are values ​​calculated as standard polystyrene by the GPC method. The detailed measurement conditions are as follows. GPC measurement was performed using SD-8022 / DP-8020 / RI-8020 manufactured by Tosoh Corporation, Gelpack GL-A150-S / GL-A160-S manufactured by Hitachi Chemical Co., Ltd. as the column, and tetrahydrofuran as the eluent.

[0077] <Measurement of Loss Tangent> A dicing film with a rectangular main surface measuring 5 mm on the short side and 8 mm on the long side was prepared as a measurement sample. The measurement sample was placed on a solid shearing jig as shown in Figure 2, and the MD direction of the substrate film (machine direction, the direction parallel to the longitudinal direction (flow direction) of the original roll from which the substrate film is obtained) was fixed as the short side. Viscoelasticity measurements were performed using the following equipment and measurement conditions to determine the loss tangent at 0°C (0°C tan δ). [Device Information] Dynamic Viscoelasticity Measuring Apparatus (DMA) Rheogel-E4000 manufactured by UBM Corporation [Measurement Conditions] Measurement Jig: Solid Shearing Jig M039 Frequency: 10 Hz Sine Wave Strain (Strain Amount): 1% of Total Thickness Sample Size: 5 x 8 mm Heating Rate: 2°C / min Clamping Pressure: Torque Wrench 9 cN m

[0078] <Evaluation of Dividability> [Preparation of Evaluation Sample] An evaluation sample was prepared according to the following procedure. A protective tape was attached to the surface of a silicon wafer (diameter: 12 inches, thickness: 775 μm). The silicon wafer was then singulated by stealth dicing. That is, a modified region was formed inside the silicon wafer by irradiating the surface (back surface) of the silicon wafer opposite to the side where the protective tape was attached with laser light under the following conditions. (Stealth Dicing Conditions) Stealth dicing device: DFL7361 (manufactured by Disco Corporation) Laser oscillator type: semiconductor laser excited Q-switched solid state laser Wavelength: 1342 nm Frequency: 60 kHz Output: 0.8 W Number of passes: 2 Chip size: 3 mm × 12 mm Dicing speed: 800 mm / sec

[0079] Next, the surface of the silicon wafer opposite the protective tape was ground (polished) using a grinder polisher device (DGP8761, manufactured by Disco Corporation) until the thickness of the silicon wafer was 30 μm, and the silicon wafer was singulated to obtain silicon chips. A die bonding film of a dicing / die bonding integrated film was attached to the surface of the silicon chip opposite the protective tape under the following attachment conditions. At this time, the attachment direction was adjusted so that the direction of the division line of the silicon chip was along the MD direction and TD direction (transverse direction, direction perpendicular to the MD direction (vertical direction)) of the base film of the dicing / die bonding integrated film. The silicon wafer was attached so that the long side of the chip was perpendicular to the MD direction. Furthermore, the adhesive layer protruding from the die bonding film was attached to a dicing ring, and then the protective tape was peeled off from the silicon wafer. (Application conditions) Application device: DFM2800 (manufactured by Disco Corporation) Application temperature: 65°C Application speed: 10 mm / s Application tension level: Level 5

[0080] Next, using a die separator (DDS2300, manufactured by Disco Corporation), the dicing film of the dicing-die bonding integrated film was stretched by cooling and expanding under the following cooling and expanding conditions, thereby dividing the die bonding film: (Cooling and Expanding Conditions) Cooling temperature: 0°C Cooling time: 120 seconds Push-up amount: 8 mm Push-up speed: 120 mm / sec Holding time after push-up: 10 seconds

[0081] [Separability Evaluation] The separability of the samples after the die bonding film was separated by cooling and expanding was evaluated using the following procedure. The results are shown in Tables 1 and 2. The separation state of the die bonding film was confirmed by magnifying the space between the chips from above in the direction along the chip long side (12 mm) and the direction along the chip short side (3 mm) using a measuring microscope (MF-U) manufactured by Mitutoyo Corporation. 216 locations on each of the chip long side and short side (total number of observations: 432) were observed. The chip long side and short side observed were selected from one side of the chip formed by separating the chip along any of the 3rd, 8th, 13th, 18th, and 23rd rows of the 26 rows of separation lines along the chip short side (216 locations on the long side and 216 locations on the short side, a total of 432 locations). If the die bonding film was separated along the entire side, it was judged as OK. If the entire side or a portion of the side remained unseparated, it was judged as NG. The separability was evaluated by the NG rate of separability calculated by the formula: (NG number / total number of observations) × 100. If the NG rate of separability was 1% or less, it was evaluated as "A", if it was more than 1% and less than 3%, it was evaluated as "B", and if it was more than 3%, it was evaluated as "C".

[0082]

[0083]

[0084] As shown in Tables 1 and 2, the dicing and die bonding integrated films of Examples 1 to 5, in which the tan δ of the dicing film at 0°C was 0.15 or less, were superior in terms of separability to the dicing and die bonding integrated films of Comparative Examples 1 and 2, in which the tan δ at 0°C was greater than 0.15.

[0085] From the above, it has been confirmed that, according to the present disclosure, the cooling separation property of the die bonding film can be improved in a predetermined method for manufacturing a semiconductor device.

[0086] 1... die bonding film, 1a... die bonding film piece, 2... adhesive layer, 3... base film, 5... dicing film, 5A, 5B... measurement sample, 7... protective tape, 10... dicing and die bonding integrated film, 30... semiconductor chip with die bonding film piece, 50... solid shearing jig, 51... first plate-shaped member, 52a, 52b... second plate-shaped member, C... semiconductor chip.

Claims

1. A dicing film comprising a base film and an adhesive layer provided on the base film, and an adhesive layer made of a die bonding film arranged on the adhesive layer of the dicing film, wherein the loss tangent of the dicing film at 0°C is 0.15 or less, and the loss tangent is: preparing a measurement sample of the dicing film having a rectangular main surface with a short side of 5 mm and a long side of 8 mm; in a viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) equipped with a solid shearing jig having a first plate-like member and a pair of second plate-like members, arranging two of the measurement samples between the two measurement samples with the main surface of the adhesive layer in a direction in which the first plate-like member is in contact with the first plate-like member, and fixing the measurement sample to the solid shearing jig by clamping the measurement sample from the thickness direction with each of the pair of second plate-like members under the condition that the clamping pressure is 9 cN・m with a torque wrench; determining the loss tangent by dynamic viscoelastic measurement in a shear mode using the solid shear jig to which the measurement sample is fixed, under conditions of a measurement frequency of 10 Hz, a distortion amount of 1% relative to the total thickness of the dicing film, and a temperature increase rate of 2°C / min.

2. The dicing-die bonding integrated film according to claim 1, wherein the loss tangent at 0° C. is 0.07 or less.

3. The dicing and die bonding integrated film according to claim 1 or 2, wherein the thickness of the adhesive layer is 10 μm or less.

4. A method for manufacturing a dicing film comprising a base film and an adhesive layer provided on the base film, the dicing film having a loss tangent of 0.15 or less at 0°C, and a step of bonding a die bonding film and the adhesive layer of the dicing film, the loss tangent being: preparing a measurement sample of the dicing film having a rectangular main surface with a short side of 5 mm and a long side of 8 mm; arranging two of the measurement samples in a viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) having a solid shearing jig having a first plate-like member and a pair of second plate-like members, with the main surface of the adhesive layer in a direction in which the first plate-like member is in contact with the first plate-like member, and clamping the measurement sample from the thickness direction with each of the pair of second plate-like members under a condition of a clamping pressure of 9 cN・m with a torque wrench, thereby fixing the measurement sample to the solid shearing jig; determining the loss tangent by dynamic viscoelastic measurement in a shear mode using the solid shear jig to which the measurement sample is fixed under conditions of a measurement frequency of 10 Hz, a distortion amount of 1% relative to the total thickness of the dicing film, and a heating rate of 2°C / min.

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