Method for evaluating dicing film

Abstract

To provide a method for simply evaluating an influence of a dicing film that imparts on divisiveness in a cooling and expanding step.SOLUTION: A method for evaluating a dicing film that includes a base material film and an adhesive layer provided on the base material film, comprises the steps of: measuring a loss tangent of the dicing film at or below 0°C using a dynamic viscoelastic measurement device equipped with a solid shear jig through dynamic viscoelastic measurement in shear mode; and evaluating the influence of the dicing film on the separability in the cooling and expanding process based on the loss tangent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for evaluating a dicing film. [Background technology]

[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 the like.

[0003] In the manufacturing process of a semiconductor device, a dicing-die bonding integrated film is sometimes used, in which a dicing film having a base film and an adhesive layer is integrated with a die bonding film for bonding between a substrate or another semiconductor chip. The dicing-die bonding integrated film is used, for example, as follows. First, the surface of the die bonding film (adhesive layer) is attached to a wafer, and the wafer is diced while being fixed with a dicing ring. This causes the wafer to be singulated into a large number of chips. Next, the adhesive layer is irradiated with ultraviolet light to reduce the adhesive force of the adhesive layer to the die bonding film, and then the chip is picked up from the adhesive layer together with the die bonding film piece formed by singulating the die bonding film. Then, the semiconductor device is manufactured through a process of mounting the chip on a substrate or the like through the die bonding film piece. The laminate consisting of the chip obtained through the dicing process and the die bonding film piece attached thereto is called a semiconductor chip with die bonding film piece.

[0004] Conventionally, blade dicing, which is cutting with a blade or the like, has been widely known as a method for dicing wafers and die bonding films. In recent years, stealth dicing has become more widespread 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 with a laser, and then the wafer and die bonding film are cut along the cutting line to obtain semiconductor chips with die bonding film pieces. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2002-192370 A [Patent Document 2] JP 2003-338467 A Summary of the Invention [Problem to be solved by the invention]

[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, below 0°C) (hereinafter, sometimes referred to as "cooling expansion") may be performed. In cooling expansion, the die bonding film may be difficult to divide. If the die bonding film is not easily divided, it becomes difficult to pick up the semiconductor chip with the die bonding film piece, and there is a risk of a decrease in yield in the manufacture of semiconductor devices.

[0007] In developing a dicing and die bonding integrated film, process evaluation simulating the actual situation is common, but a simpler method for evaluating the performance of the dicing film is required. A simple method for evaluating the effect of the dicing film on the separability in the cooling and expanding process is thought to provide a better guideline for understanding the degree of improvement in the performance of the dicing film.

[0008] The main object of the present disclosure is to provide a method for easily evaluating the effect of a dicing film on the separability in a cooling and expanding process. [Means for solving the problem]

[0009] [1] A method for evaluating a dicing film including a base film and a pressure-sensitive adhesive layer provided on the base film, the method comprising: a step of measuring the loss tangent of the dicing film at or below 0°C by shear mode dynamic viscoelasticity measurement using a dynamic viscoelasticity measuring device equipped with a solid shear jig; and a step of evaluating the effect of the dicing film on the separability in a cooling and expanding step based on the loss tangent. [2] The method according to [1], wherein the dicing film is used as an integrated dicing / die bonding film. [3] The method according to [1] or [2], wherein in the step of measuring the loss tangent, the loss tangent is measured at 0°C. [4] The loss tangent is obtained by 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, and in a viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) equipped with a solid shearing jig having a first plate-shaped member and a pair of second plate-shaped members, the two measurement samples are arranged so that the first plate-shaped member is sandwiched between the two measurement samples with the main surface of the pressure-sensitive adhesive layer in a direction in which it is in contact with the first plate-shaped member, and a clamping pressure is applied by each of the pair of second plate-shaped members. and determining the loss tangent by dynamic viscoelastic measurement in a shear mode 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. [5] The method according to [4], wherein the evaluation criterion is whether the loss tangent at 0°C is 0.15 or less. Effect of the Invention

[0010] According to the present disclosure, a method for easily evaluating the effect of a dicing film on the separability in the cooling and expanding process is provided. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram for explaining a method for measuring the loss tangent of a dicing film at 0° C. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the 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, the components (including steps, etc.) are not essential unless specifically stated. The size of the components in each figure is conceptual, and the relative relationship of the size between the components is not limited to that shown in each figure.

[0013] The same applies to the numerical values ​​and their ranges in this specification, and they do not limit the present disclosure. In this specification, a numerical range indicated using "~" indicates a range including the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this specification, the upper limit or lower limit value described in one numerical range may be replaced with the upper limit or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in this specification, the upper limit or lower limit value of the numerical range may be replaced with a value shown in the examples.

[0014] In this specification, "(meth)acrylate" means at least one of 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 a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0015] [Evaluation method for dicing film] The method disclosed herein is a method for evaluating a dicing film including a base film and a pressure-sensitive adhesive layer provided on the base film, and includes a step (measurement step) of measuring the loss tangent of the dicing film at 0° C. or lower by dynamic viscoelasticity measurement in a shear mode using a dynamic viscoelasticity measuring device equipped with a solid shear jig, and a step (evaluation step) of evaluating the effect of the dicing film on the separability in a cooling and expanding step based on the loss tangent.

[0016] <Measurement process> In the measurement step, the loss tangent of the dicing film is measured at 0°C or lower by dynamic viscoelasticity measurement in a shear mode using a dynamic viscoelasticity measuring device equipped with a solid shear jig. The loss tangent is the ratio of the loss modulus to the storage modulus. The dynamic viscoelasticity measuring device may be, for example, Rheogel-E4000 (manufactured by UBM Corporation).

[0017] 1 is a schematic diagram for explaining a method for measuring the loss tangent. Two measurement samples 5A and 5B each having an adhesive layer 2 and a base film 3 are fixed to a solid shearing jig 50. The solid shearing jig 50 has a first plate-shaped member 51 and a pair of second plate-shaped 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-shaped member 51 and the second plate-shaped members 52a and 52b may each be a plate-shaped member made of stainless steel (SUS). The first plate-shaped member is fixed to a dynamic viscoelasticity measuring device, and the measurement samples 5A, 5B are fixed to a solid shearing jig 50 by the second plate-shaped members 52a, 52b, and the measurement samples 5A, 5B are vibrated in the direction indicated by d1, thereby applying stress to the measurement samples 5A, 5B in the shear direction (direction d1).

[0018] The measurement samples 5A and 5B are arranged so as to sandwich the first plate-like member 51 with the main surface of the adhesive layer 2 in a direction in contact with the first plate-like member 51. The measurement samples 5A and 5B are arranged so that the main surface on the base film 3 side is in a direction in contact with the second plate-like members 52a and 52b, respectively. The measurement samples 5A and 5B are fixed to the solid shear jig 50 by being clamped from directions d2 and d3 by a pair of second plate-like members 52a and 52b. The main surface of the first plate-like member 51 in contact with the adhesive layer 2 may be the same or approximately the same size as the main surface of the 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.

[0019] The measurement samples 5A and 5B can be prepared by cutting the dicing film to be measured to a predetermined size as necessary. The measurement samples 5A and 5B are samples prepared from the same dicing film to be measured. The measurement samples 5A and 5B may have a rectangular main surface with a length in a first direction of 2 to 10 mm and a length in a second direction perpendicular to the first direction of 2 to 8 mm, for example.

[0020] The measurement samples 5A and 5B may be fixed to the solid shearing jig 50 so that the MD direction of the base film 3 is the short side and is the same direction as the vibration direction d1 of the solid shearing jig 50. The measurement samples 5A and 5B may be fixed to the solid shearing jig 50 so that the TD direction of the base film 3 is the long side and is 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 original roll from which the base film 3 is obtained. The TD direction (Transverse Direction) is the direction perpendicular to the MD direction (vertical direction).

[0021] The clamping pressure applied by the second plate-like members 52a, 52b may be adjusted as appropriate depending on the type of device or instrument used, etc. The clamping pressure applied by the second plate-like members 52a, 52b may be, for example, 1 to 15 cN·m.

[0022] The measurement frequency may be 0.1 to 200 Hz, 0.5 to 100 Hz, or 1 to 50 Hz.

[0023] The amount of distortion may be 0.1 to 300%, 0.1 to 50%, or 0.1 to 5% relative to the total thickness of the dicing film.

[0024] The temperature rise rate may be 1 to 20° C. / min, 1 to 5° C. / min, or 1 to 2° C. / min. A slower temperature rise rate is preferable because it allows the temperature of the measurement sample itself to more easily follow the measurement temperature.

[0025] The loss tangent to be measured is a loss tangent at 0°C or lower, and may be a loss tangent at -15 to 0°C, or may be a loss tangent at 0°C.

[0026] The loss tangent was measured by (1) preparing a measurement sample of a dicing film having a rectangular main surface with a short side of 5 mm and a long side of 8 mm, (2) using a viscoelasticity measuring device (Rheogel-E4000, manufactured by UBM Co., Ltd.) equipped with a solid shearing jig having a first plate-shaped member and a pair of second plate-shaped members, placing two measurement samples between the two measurement samples with the main surface of the adhesive layer in contact with the first plate-shaped member, and applying a clamping pressure to each of the pair of second plate-shaped members. (2) fixing the measurement sample to a solid shearing jig by tightening it in the thickness direction of the measurement sample under conditions of a torque wrench of 9 cN m, and (3) determining the loss tangent by dynamic viscoelastic measurement in a shear mode 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 (hereinafter also referred to as "Measurement Method A").

[0027] The measuring step may be a step of measuring a loss tangent at 0° C. or lower obtained by the above-mentioned measuring method A.

[0028] The pressure-sensitive adhesive layer 2 and base film 3 constituting the dicing film to be measured are not particularly limited, and may be the pressure-sensitive adhesive layer and base film typically used in dicing films.

[0029] The adhesive layer 2 may be a layer formed of an adhesive that is normally used in dicing films. The adhesive constituting the adhesive layer 2 may be an ultraviolet-curing adhesive or a non-ultraviolet-curing adhesive. The ultraviolet-curing adhesive is an adhesive that has a property of decreasing its adhesiveness by ultraviolet irradiation. By using an ultraviolet-curing adhesive, for example, the adhesive strength of the adhesive layer 2 can be decreased by ultraviolet irradiation before picking up the semiconductor chip to which the die bonding film piece is attached.

[0030] The ultraviolet curing 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 curing 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. An example of the crosslinking agent is a polyisocyanate compound.

[0031] 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, or 6 μm or less. 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.

[0032] Resins constituting the base film 3 include homopolymers and copolymers of olefins such as ethylene, propylene, butene, hexene, methylpentene, 4-methyl-1-pentene, and vinyl acetate; polyesters such as polyethylene terephthalate and polyethylene naphthalate; ethylene copolymers such as ethylene-vinyl acetate copolymers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester copolymers, and ethylene-(meth)acrylic acid-(meth)acrylic acid ester copolymers; and copolymers containing an olefin such as ethylene and (meth)acrylic acid, in which the acid portion is Examples of the base material include ionomer resins having an ion-crosslinked structure formed by salt formation between the base material 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; or mixtures of these with plasticizers, or cured products crosslinked by electron beam irradiation. The base material film may be composed of one type of resin alone, or may be composed of a mixed resin of two or more types of resins. The base material film may also be a film having a laminate structure in which two or more types of films are laminated. In order to control the adhesion to the pressure-sensitive adhesive layer 2, the surface of the base material film may be subjected to a surface roughening treatment such as a matte treatment or a corona treatment. The base material film 3 may be a base material film containing at least one resin selected from the group consisting of polyester, ethylene copolymer, ionomer resin, and engineering plastic.

[0033] The substrate film 3 can be produced by film formation by a conventionally known method. For example, the resin composition obtained by adding additives such as an antistatic agent to the resin raw material of the substrate as necessary and melt-kneading the resin composition can be produced by processing the resin composition into a film shape by various molding methods such as T-die casting molding, T-die nip molding, inflation molding, extrusion lamination, and calendar molding. In addition, when the substrate film has a laminated structure, each layer can be separately formed into a film by means of calendar molding, extrusion, inflation molding, etc., and laminated by means of thermal lamination or adhesion with an adhesive, etc., to produce a laminated structure. As the adhesive, an adhesive that is usually used when producing a laminated structure can be used. In addition, the resin compositions of each layer can be simultaneously extruded by a co-extrusion lamination method to produce a laminated structure. In addition, the surface of the substrate film opposite to the surface in contact with the pressure-sensitive adhesive layer may be embossed with a shiborol for the purpose of stabilizing the winding during the production of the substrate film 3 and preventing blocking after film formation.

[0034] 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. 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, or 100 μm or less, which is economically advantageous.

[0035] 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 one long base film 3.

[0036] The thickness of the dicing film to be measured (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.

[0037] The dicing film can be used as a dicing / die bonding integrated film. The dicing / die bonding integrated film includes a die bonding film (hereinafter sometimes referred to as an "adhesive layer") and a dicing film having a pressure-sensitive adhesive layer attached to the die bonding film 1.

[0038] The die bonding film 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 has, for example, a circular main surface that covers the entire main surface of a semiconductor wafer. The die bonding film may be a film formed from an adhesive that is commonly used for bonding semiconductor chips.

[0039] The thickness of the die bonding film (adhesive layer) may be, for example, 100 μm or less, 90 μm or less, 80 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 1 μm or more, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more.

[0040] <Evaluation process> In the evaluation process, the effect of the dicing film on the separability in the cooling and expanding process is evaluated based on the loss tangent. The lower the value of the loss tangent, the more improved the separability in the cooling and expanding process can be evaluated. The inventors speculate that the lower the value of the loss tangent, the smaller the loss of the breaking stress caused by the dicing film in the cooling and expanding process, and as a result, the stress transmitted to the die bonding film becomes stronger, resulting in improved separability in the cooling and expanding process, but the mechanism is not limited to this.

[0041] In the evaluation step, the evaluation criterion can be whether the loss tangent at 0° C. or below is a predetermined value or below. The numerical value used as the evaluation criterion can be appropriately set according to various manufacturing conditions in the semiconductor manufacturing process, the composition of the die bonding film used together with the dicing film as the measurement target, and the like.

[0042] In the evaluation step, the evaluation criterion may be whether or not the loss tangent at 0° C. measured by the above-mentioned measurement method A is 0.15 or less. The loss tangent at 0° C. used as the evaluation criterion may be, for example, 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, or may be 0.01 or more, or 0.02 or more.

[0043] The cooling and expanding step is a step of expanding (stretching) the dicing film under cooling conditions. The cooling and expanding step may be, for example, a step of expanding, under cooling conditions, the dicing film of a laminate including the above-mentioned dicing-die bonding integrated film and a plurality of semiconductor chips formed by dividing a semiconductor wafer, which are provided on the die bonding film of the dicing-die bonding integrated film. The temperature of the cooling condition may be, for example, -15 to 0°C. The die bonding film is divided by expanding the dicing film. By this division, a semiconductor chip with a die bonding film piece, which has a semiconductor chip and a die bonding film piece obtained by dividing the die bonding film, is formed on the adhesive layer.

[0044] Since the method disclosed herein does not necessarily require process evaluation that mimics the actual situation, the method disclosed herein makes it possible to more easily obtain information that serves as a guide for obtaining a dicing film that can improve the separability in the cooling and expanding process. EXAMPLES

[0045] The present disclosure will be described in more detail below with reference to examples, although the present disclosure is not limited to these examples.

[0046] Manufacturing Example 1 1-1. Preparation of adhesive layer (Production Example A-1) Acrylic polymer 1, which is a copolymer of the following monomers, was prepared. The weight average molecular weight (Mw) of acrylic polymer 1 is 910,000, the number average molecular weight (Mn) is 140,000, and Mw / Mn is 6.5. The hydroxyl value of acrylic polymer 1 is 2.5 mgKOH / g. Butyl acrylate: 88.1 parts by weight 2-Hydroxyethyl methacrylate: 0.6 parts by weight Acrylonitrile: 11.2 parts by weight

[0047] To 100 parts by mass of acrylic polymer 1 (calculated as 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%) was mixed as a crosslinking agent, and the mixture was diluted with methyl ethyl ketone (MEK) and stirred to prepare adhesive solution A-1.

[0048] Adhesive solution A-1 was applied to a polyethylene terephthalate film (thickness 38 μm) with one side having been subjected to a release treatment so that the thickness after drying would be 10 μm, and then dried at 80° C. for 3 minutes to form an adhesive layer of Production Example A-1 on the polyethylene terephthalate film.

[0049] 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, 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 base film of Production Example B-1.

[0050] 1-3. Preparation of dicing film A base film (Production Example B-1) having one side subjected to a corona discharge treatment was bonded to the adhesive layer of Production Example A-1. The bonded sample was aged in a thermostatic chamber at 23° C. for 96 hours to produce a dicing film.

[0051] 1-4. Preparation of adhesive layer (Production Example C-1) HTR-860P-3 (trade name, Nagase ChemteX Corporation, glycidyl group-containing acrylic rubber, molecular weight 1 million, Tg-7°C) 100 parts by weight, YDCN-700-10 (trade name, Nippon Steel & Sumikin Chemical Co., Ltd., o-cresol novolac type epoxy resin, epoxy equivalent 210) 20 parts by weight, Milex XLC-LL (trade name, Mitsui Chemicals, Inc., phenol aralkyl resin) 17 parts by weight, 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 onto 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).

[0052] 1-5. Preparation of dicing / die bonding integrated film (production example 1) The adhesive layer (die bonding film) and the dicing film were attached so that the adhesive layer of the die bonding film was in contact with the pressure-sensitive adhesive layer of the dicing film, thereby obtaining a dicing-die bonding integrated film of Production Example 1.

[0053] Manufacturing Example 2 2-1. Preparation of adhesive layer (Production Example A-2) Acrylic polymer 2, which is 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 weight 2-Hydroxyethyl methacrylate: 4.8 parts by weight Acrylonitrile: 24.0 parts by weight

[0054] Acrylic polymer 1 was mixed at 70 parts by mass in terms of solid content, acrylic polymer 2 was mixed at 30 parts by mass in terms of solid content, and a crosslinking agent, Coronate L38ET (manufactured by Tosoh Corporation, TMP adduct of tolylene diisocyanate, Nv 37.5%, TDI adduct trifunctional NCO% 6.6%), was mixed at a ratio of 2.2 parts by mass in terms of solid content, diluted with methyl ethyl ketone (MEK), and stirred to prepare adhesive solution A-2. The adhesive layer of Manufacturing Example A-2 was prepared in the same manner as Manufacturing Example A-1, except that adhesive solution A-2 was used instead of adhesive solution A-1.

[0055] 2-2. Preparation of dicing / die bonding integrated film (production example 2) A dicing / die bonding integrated film of Production Example 2 was produced in the same manner as in Production Example 1, except that the adhesive layer of Production Example A-2 was used as the adhesive layer.

[0056] Production Example 3 3-1. Preparation of adhesive layer (Production Example A-3) As copolymerization monomer components, 2-ethylhexyl acrylate (EHA), 2-hydroxyethyl acrylate (HEA), and methyl methacrylate (MMA) were prepared. These copolymerization monomer components were mixed to a copolymerization ratio of EHA / HEA / MMA = 78 parts by mass / 21 parts by mass / 1 part by mass, and an acrylic copolymer was obtained by solution radical polymerization using ethyl acetate as a solvent and 0.08 parts by mass of azobisisobutyronitrile (AIBN) as an initiator. This acrylic copolymer was reacted with 16 parts by mass of 2-methacryloyloxyethyl isocyanate (trade name: Karenz MOI, molecular weight: 155.15) using 0.05 parts by mass of hydroquinone monomethyl ether as a polymerization inhibitor to synthesize an ultraviolet-curable adhesive having a carbon-carbon double bond. The weight-average molecular weight of the obtained ultraviolet-curable 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 of the obtained ultraviolet curing adhesive in terms of solid content, 1.0 part by mass of an α-hydroxyalkylphenone photopolymerization initiator (trade name: Omnirad184) manufactured by IGM Resins BV, 0.2 parts by mass of an acylphosphine oxide photopolymerization initiator (trade name: Omnirad819) manufactured by IGM Resins BV, and 2.07 parts by mass of a TDI-based polyisocyanate crosslinking agent (trade name: Coronate L-45E) manufactured by Tosoh Corporation as a crosslinking agent in terms of solid content were mixed in a ratio of 100 parts by mass of the obtained ultraviolet curing adhesive in terms of solid content, diluted with ethyl acetate, and stirred to prepare an adhesive solution A-3. The adhesive layer of Production Example A-3 was prepared in the same manner as in Production Example A-1, except that the adhesive solution A-3 was used instead of the adhesive solution A-1.

[0057] 3-2. Preparation of dicing / die bonding integrated film (production example 3) A dicing / die bonding integrated film of Production Example 3 was produced in the same manner as in Production Example 1, except that the adhesive layer of Production Example A-3 was used as the adhesive layer.

[0058] Production Example 4 4-1. Preparation of adhesive layer (Production Example A-4) The ultraviolet-curable adhesive prepared in Production Example A-3 was mixed in a ratio of 100 parts by weight in terms of solid content, 1.0 part by weight of an α-hydroxyalkylphenone-based photopolymerization initiator (trade name: Omnirad184) manufactured by IGM Resins BV, 0.2 parts by weight of an acylphosphine oxide-based photopolymerization initiator (trade name: Omnirad819) manufactured by IGM Resins BV, and 4.14 parts by weight of a TDI-based polyisocyanate-based crosslinking agent (trade name: Coronate L-45E) manufactured by Tosoh Corporation as a crosslinking agent, diluted with ethyl acetate and stirred to prepare an adhesive solution A-4. The adhesive layer of Production Example A-4 was prepared in the same manner as Production Example A-1, except that the adhesive solution A-4 was used instead of the adhesive solution A-1.

[0059] 4-2. Preparation of dicing / die bonding integrated film (production example 4) The dicing / die bonding integrated film of Production Example 3 was produced in the same manner as in Production Example 1, except that the adhesive layer of Production Example A-4 was used as the adhesive layer.

[0060] Manufacturing Examples 5-7 5-1. Preparation of adhesive layer (Production Example A-5) The ultraviolet-curable adhesive was synthesized in the same manner as in the preparation of the ultraviolet-curable adhesive in Production Example 3, 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 (product name: Karenz MOI, molecular weight: 155.15) was reacted. The weight-average molecular weight of the obtained ultraviolet-curable adhesive was 350,000. The hydroxyl value and acid value of the obtained ultraviolet-curable adhesive were 27.5 mg KOH / g and 6.5 mg KOH / g, respectively. The adhesive layer of Production Example A-5 was prepared in the same manner as in Production Example A-1, except that the obtained ultraviolet-curable adhesive was used and the thickness of the adhesive layer was changed to the thickness shown in Table 2.

[0061] 5-2. Preparation of dicing / die bonding integrated film (production example A-5) The dicing and die bonding integrated film of Production Example A-5 was produced in the same manner as Production Example 1, except that the adhesive layer of Production Example A-5 was used as the adhesive layer and the thickness of the adhesive layer of Production Example C-1 was changed to 7 μm.

[0062] 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.

[0063] <Measurement of weight average molecular weight and number average molecular weight> The weight average molecular weight is a value calculated as a standard polystyrene equivalent by the GPC method. The detailed measurement conditions are as follows: GPC measurements were 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 columns, and tetrahydrofuran as an eluent.

[0064] <Loss tangent measurement> A dicing film with a rectangular main surface with a short side of 5 mm and a long side of 8 mm was prepared as a measurement sample. The measurement sample was placed in a solid shearing jig as shown in Figure 1, and the MD direction (machine direction, the direction parallel to the longitudinal direction (flow direction) of the original roll from which the substrate film is applied) of the substrate film was fixed as the short side. Viscoelasticity measurements were performed using the following equipment and measurement conditions, and the loss tangent at 0°C (0°C tan δ) was obtained. [Device information] Dynamic Viscoelasticity Measuring Instrument (DMA) Rheogel-E4000 manufactured by UBM Corporation [Measurement conditions] · Measurement fixture: Solid shear fixture M039 Frequency: 10Hz ·Sine wave Distortion (amount of distortion): 1% of total thickness Sample size: 5×8mm Heating rate: 2℃ / min ·Tightening pressure: Torque wrench 9cN·m

[0065] <Dividability assessment> [Preparation of evaluation samples] The 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 divided into individual pieces 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 equipment: DFL7361 (manufactured by Disco Corporation) Laser oscillator type: Semiconductor laser pumped Q-switched solid-state laser ·Wavelength: 1342nm Frequency: 60kHz Output power: 0.8W Number of passes: 2 Chip size: 3mm x 12mm Dicing speed: 800mm / sec

[0066] Next, the surface of the silicon wafer opposite to 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 divided into individual pieces to obtain silicon chips. The die bonding film of the dicing-die bonding integrated film was attached to the surface of the silicon chip opposite to 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) 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 of the part protruding from the die bonding film was attached to a dicing ring, and then the protective tape was peeled off from the silicon wafer. (Conditions for attachment) - Application device: DFM2800 (manufactured by Disco Corporation) Application temperature: 65℃ Application speed: 10mm / s - Application tension level: Level 5

[0067] Next, the dicing film of the dicing-die bonding integrated film was stretched by cooling and expanding under the following cooling and expanding conditions using a die separator (DDS2300, manufactured by Disco Corporation), thereby dividing the die bonding film. (Cooling expansion conditions) ·Cooling temperature: 0℃ ·Cooling time: 120 seconds Thrust amount: 8mm - Thrust speed: 120mm / sec Holding time after thrust: 10 seconds

[0068] [Disruptiveness assessment] After the die bonding film was divided by cooling and expanding, the samples were evaluated for their severability according to the following procedure. The results are shown in Tables 1 and 2. The separation state of the die bonding film was confirmed by enlarging and observing the gap between the chips from above along the chip long side (12 mm) and 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 (216 locations on the long side and 216 locations on the short side, total of 432 locations) formed by dividing along any of the dividing lines of the 3rd, 8th, 13th, 18th, and 23rd rows out of the 26 rows of dividing lines along the chip short side. If the die bonding film was cut along the entire side, it was judged as OK, and if the entire side or part of the side remained uncut, it was judged as NG. The separation was evaluated by the separation NG rate calculated by the formula: (NG number / total number of observations) x 100. If the rate of disruptive NG was 1% or less, it was rated as "A", if it was between 1% and 3%, it was rated as "B", and if it was over 3%, it was rated as "C".

[0069] [Table 1]

[0070] [Table 2]

[0071] As shown in Tables 1 and 2, it was shown that the separability in the cooling and expanding process improved as the tan δ of the dicing film at or below 0°C decreased. From the above results, it was confirmed that the separability in the cooling and expanding process can be evaluated by the tan δ of the dicing film at or below 0°C. [Explanation of symbols]

[0072] 2...adhesive layer, 3...base film, 5A, 5B...measurement sample, 50...solid shear jig, 51...first plate-like member, 52a, 52b...second plate-like member.

Claims

1. A method for evaluating a dicing film including a base film and a pressure-sensitive adhesive layer provided on the base film, comprising: Measuring the loss tangent of the dicing film at 0° C. or lower by dynamic viscoelasticity measurement in a shear mode using a dynamic viscoelasticity measuring device equipped with a solid shear jig; and evaluating an effect of the dicing film on breakability in a cooling and expanding process based on the loss tangent.

2. The method according to claim 1 , wherein the dicing film is used as a dicing / die bonding integrated film.

3. The method according to claim 1 or 2, wherein the loss tangent is measured at 0° C. in the step of measuring the loss tangent.

4. 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 Corporation) equipped with a solid shearing jig having a first plate-like member and a pair of second plate-like members, two sheets of the measurement samples are arranged so that the first plate-like member is sandwiched between the two sheets of the measurement samples with the main surface of the pressure-sensitive adhesive layer in a direction in which the pressure-sensitive adhesive layer is in contact with the first plate-like member, and the measurement samples are fixed to the solid shearing jig by clamping from a thickness direction of the measurement samples with each of the pair of second plate-like members under a condition that the clamping pressure is a torque wrench of 9 cN m; and The loss tangent is obtained by dynamic viscoelasticity measurement in a shear mode 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 temperature rise rate of 2°C / min. The method according to claim 1 or 2, wherein the value is determined by a method comprising:

5. The method according to claim 4, wherein the evaluation criterion is whether the loss tangent at 0°C is 0.15 or less.

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