JP2011023632A - Base film for dicing and dicing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dicing film which hardly causes cutting chips (string- or whisker-like chips generated from a film after dicing) during a dicing process of a semiconductor wafer and is excellent in expandability; and to provide a base film for dicing used for the dicing film. <P>SOLUTION: The base film for dicing has an A-layer, a B-layer and a C-layer laminated in this order, wherein the A-layer is composed of a resin composition containing 30-80 wt.% of copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or its hydrogenation object and 70-20 wt.% of polypropylene-based resin; the B-layer is composed of a resin composition containing 0-20 wt.% of polypropylene-based resin and 100-80 wt.% of olefin-based thermoplastic elastomer; and the C-layer is composed of a resin composition containing 0-40 wt.% of copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or its hydrogenation object and 100-60 wt.% of polypropylene-based resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a dicing film for fixing a semiconductor wafer or the like when the semiconductor wafer or the like is diced into chips.

  A semiconductor wafer is made in advance in a large area, then diced (cut and separated) into chips and transferred to an expanding process. In the dicing, a dicing film is used for fixing the semiconductor wafer.

  The dicing film is basically composed of an adhesive layer for fixing a semiconductor wafer and a resin layer (a substrate film for dicing) that receives the cutting of a dicing blade. The semiconductor wafer fixed to the dicing film is diced into chips, and is picked up after being uniformly expanded in the surface direction on the expanding ring in order to separate the chips.

  In the semiconductor wafer dicing process, the adhesive layer or a part of the substrate film for dicing is also cut together with the wafer, so that the resin becomes a molten state due to frictional heat of the resin, and resin-derived cutting waste (dicing waste) is generated. Since this cutting waste contaminates the wafer and lowers the yield of chips, it is necessary to reduce it as much as possible.

  For example, the following dicing film has been reported mainly for the purpose of eliminating cutting waste in the dicing process.

  Patent Document 1 describes a polyolefin film such as polyethylene irradiated with 1 to 80 Mrad of an electron beam or γ-ray as a base film. However, since this film crosslinks the entire crosslinkable resin with an electron beam or the like, it becomes hard and sufficient expandability cannot be obtained.

  Patent Document 2 describes an ethylene / methyl methacrylate copolymer film as a base film. However, although this film can reduce a certain amount of cutting waste, it is not always sufficient.

  Patent Document 3 mainly discloses a resin layer B mainly composed of an ionomer resin obtained by crosslinking a terpolymer of ethylene, (meth) acrylic acid, and (meth) acrylic acid alkyl ester with metal ions, and an adhesive layer. A semiconductor wafer fixing adhesive tape laminated with A is described. However, since this film contains metal ions, contamination of the wafer becomes a problem.

  In Patent Document 4, a pressure-sensitive adhesive coated layer, a thermoplastic elastomer layer, and a resin layer are laminated in this order, and the thermoplastic elastomer layer contains 70% by mass or more of a hydrogenated styrene-butadiene copolymer. An adhesive tape base material comprising a composition and having a layer thickness of 30% or more with respect to the base material thickness is described. However, this film does not always have a sufficient cutting scrap reduction effect.

  In Patent Document 5, in a base film comprising at least two layers, polypropylene is used as a resin for the adhesive layer side, and a hydrogenated styrene-butadiene copolymer is used as a layer other than the resin layer on the adhesive layer side. The use is described.

  Patent Document 6 discloses a dicing pressure-sensitive adhesive sheet in which a pressure-sensitive adhesive layer is provided on at least one surface of a substrate film containing an olefinic thermoplastic elastomer. Although it has been disclosed that the base film is a multilayer film, the layer structure has not been sufficiently studied. Therefore, such a film of Patent Document 6 is not always sufficient in reducing cutting waste.

  Patent Documents 7 and 8 disclose a substrate film for multi-layer dicing including a layer made of a resin composition comprising a hydrogenated vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer and a polypropylene resin. Patent Documents 7 and 8 are intended to provide a dicing film having a shape restoring property, and sufficient studies have not been made on reduction of cutting waste.

Japanese Patent Laid-Open No. 5-21234 JP-A-5-156214 Japanese Patent Laid-Open No. 9-8111 JP 2005-272724 A JP 2005-174963 A JP 2003-7654 A JP 2009-94417 A JP 2009-105235 A

  An object of the present invention is to provide a dicing film that has almost no generation of cutting waste (thread-like or whisker-like waste generated from a film after dicing) in a dicing process of a semiconductor wafer and that has excellent expandability. Another object of the present invention is to provide a substrate film for dicing used for the dicing film.

  As a result of diligent research to solve the above problems, the present inventor has found that all of the above problems can be solved by forming a substrate film for dicing in which layers having a specific resin composition are laminated. It was. Based on this knowledge, further studies have been made and the present invention has been completed.

That is, the present invention provides the following dicing substrate film and dicing film.
Item 1. A substrate film for dicing laminated in the order of A layer / B layer / C layer,
The layer A consists of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof in an amount of 30 to 80% by weight and a polypropylene resin of 70 to 20% by weight,
B layer consists of a resin composition containing 0 to 20% by weight of a polypropylene resin and 100 to 80% by weight of an olefin thermoplastic elastomer,
Layer C is composed of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof of 0 to 40% by weight and polypropylene resin of 100 to 60% by weight,
Base film for dicing.
Item 2. The total thickness of the substrate film for dicing is 50 to 300 μm, the thickness of the A layer is 5 to 40%, and the thickness of the B layer is 20 to 90% with respect to the total thickness of the substrate film for dicing. 2. The substrate film for dicing according to item 1, wherein
Item 3. 3. A dicing film further comprising an adhesive layer on the A layer of the substrate film for dicing according to item 1 or 2.
Item 4. A method for producing a substrate film for dicing laminated in the order of A layer / B layer / C layer, comprising a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof in an amount of 30 to 80% by weight And a layer A resin composition comprising 70 to 20% by weight of a polypropylene resin,
B-layer resin composition containing 0 to 20% by weight of a polypropylene resin and 100 to 80% by weight of an olefinic thermoplastic elastomer, and a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene hydrocarbon or a hydrogenated product thereof 0 A resin composition for the C layer containing -40 wt% and polypropylene resin 100-60 wt%,
A production method comprising co-extrusion molding in the order of A layer / B layer / C layer.

  According to the present invention, it is possible to provide a dicing film that hardly generates cutting waste in the dicing process of a semiconductor wafer and has excellent expandability. In the dicing film of the present invention, there is almost no generation of cutting waste in the dicing process, so there is no concern of wafer contamination or IC (integrated circuit) destruction.

1. Dicing Substrate Film The dicing substrate film of the present invention is a dicing substrate film that is laminated in the order of A layer / B layer / C layer,
The layer A consists of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof in an amount of 30 to 80% by weight and a polypropylene resin of 70 to 20% by weight,
B layer consists of a resin composition containing 0 to 20% by weight of a polypropylene resin and 100 to 80% by weight of an olefin thermoplastic elastomer,
The C layer is composed of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof of 0 to 40% by weight and polypropylene resin of 100 to 60% by weight. .

  Hereinafter, each layer will be described.

1.1 A layer A layer consists of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or a hydrogenated product thereof of 30 to 80% by weight and a polypropylene resin of 70 to 20% by weight. It is a grinding layer.

(1) Copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product Vinyl aromatic hydrocarbon is an aromatic hydrocarbon having at least one vinyl group, such as styrene. , Α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, p-tert-butyl Examples thereof include styrene, 1,3-dimethylstyrene, α-methylstyrene, vinyl naphthalene, vinyl anthracene, and the like. These can be used individually by 1 type or in mixture of 2 or more types. Among these, styrene is preferable.

  The conjugated diene hydrocarbon is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1, Examples include 3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, and the like. These can be used individually by 1 type or in mixture of 2 or more types. Among these, butadiene and isoprene are preferable.

  As the resin composition for the A layer, either a copolymer of the vinyl aromatic hydrocarbon and the conjugated diene hydrocarbon or a hydrogenated product of the copolymer can be used. A hydrogenated product is preferable from the viewpoint of compatibility with the contained polypropylene resin.

  The vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer hydrogenated product is obtained by hydrogenating the above-mentioned vinyl aromatic hydrocarbon / conjugated diene hydrocarbon copolymer.

  The hydrogenation reaction is generally performed in a temperature range of 0 to 200 ° C, more preferably 30 to 150 ° C. The pressure of hydrogen used for the hydrogenation reaction is 0.1 to 15 MPa, preferably 0.2 to 10 MPa, and more preferably 0.3 to 7 MPa. The hydrogenation reaction time is usually 3 minutes to 10 hours, preferably 10 minutes to 5 hours. The hydrogenation reaction can be any of a batch process, a continuous process, or a combination thereof.

  The hydrogenation rate of the hydrogenated product of the vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer is preferably 85% or more of the double bond derived from the conjugated diene hydrocarbon in the copolymer, more preferably. Is 90% or more, more preferably 95% or more. This hydrogenation rate can be measured using a nuclear magnetic resonance apparatus (NMR).

  The content of vinyl aromatic hydrocarbon units in a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene hydrocarbon or a hydrogenated product thereof is usually 5 to 40% by weight, preferably 5 to 15% by weight. . Moreover, content of a conjugated diene hydrocarbon unit is 60 to 95 weight% normally, Preferably it is 85 to 95 weight%. The content of styrene monomer units is measured using an ultraviolet spectrophotometer or a nuclear magnetic resonance apparatus (NMR), and the content of diene monomer units is measured using a nuclear magnetic resonance apparatus (NMR). be able to.

  The hardness (JISK6253 durometer type A) of the vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer or a hydrogenated product thereof is usually about 40 to 90, preferably about 55 to 85.

  The specific gravity (ASTMD 297) of the vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer or hydrogenated product thereof is usually about 0.85 to 1.0, and MFR (ASTM D1238: 230 ° C., 21.2 N). ) Is usually about 2 to 6 g / 10 min.

  The weight average molecular weight (Mw) of the vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer or the hydrogenated product thereof is, for example, usually about 100,000 to 500,000, preferably about 150,000 to 300,000. Good. The weight average molecular weight can be measured using commercially available standard gel permeation chromatography (GPC).

  Examples of the hydrogenated vinyl aromatic hydrocarbon-conjugated diene hydrocarbon copolymer include “MD6945” manufactured by Kraton Polymer Japan Co., Ltd., “Hibler 7311” manufactured by Kuraray Co., Ltd., and the like.

(2) Polypropylene resin As the polypropylene resin (PP) used in the present invention, a crystalline resin is preferable. Examples of the crystalline propylene-based resin include a propylene homopolymer or a random or block copolymer of propylene and a small amount of α-olefin and / or ethylene.

  When the polypropylene resin is a copolymer, the copolymerization ratio of α-olefin and / or ethylene is preferably the ratio shown below.

  In the case of a random copolymer, the α-olefin and / or ethylene other than propylene is generally 10% by weight or less in total and preferably 0.5 to 7% by weight in the copolymer. In the case of a block copolymer, the α-olefin and / or ethylene other than propylene is generally 40% by weight or less, preferably 1 to 40% by weight, more preferably in the copolymer. Is 1 to 25% by weight, more preferably 2 to 20% by weight, particularly preferably 3 to 15% by weight.

  These polypropylene polymers may be a mixture of two or more polymers.

  As an index of the crystallinity of polypropylene, for example, a melting point, a heat of crystal fusion, and the like are used. The melting point is preferably 120 to 176 ° C., and the heat of crystal fusion is preferably 60 to 120 J / g.

  The polypropylene-based resin can employ multistage polymerization by combining a gas phase polymerization method, a bulk polymerization method, a solvent polymerization method and any combination thereof, and there is no particular limitation on the number average molecular weight of the polymer, Preferably, it is adjusted to 10,000 to 1,000,000.

  As this crystalline polypropylene resin, in accordance with JIS K7210, MFR (melt flow rate) when measured at a temperature of 230 ° C. and a load of 21.18 N is generally 0.5 to 20 g / 10 min. Preferably it is 0.5-10 g / 10min.

(3) Resin composition for A layer The resin composition for A layer used for the dicing film of the present invention is a copolymer of the vinyl aromatic hydrocarbon and the conjugated diene hydrocarbon or a hydrogenated product thereof of 30 to 80% by weight. And 70 to 20% by weight of the polypropylene resin, 50 to 80% by weight of the copolymer of the vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof, and 20 to 50% by weight of the polypropylene resin. The vinyl aromatic hydrocarbon and conjugated diene hydrocarbon copolymer or hydrogenated product thereof is more preferably 60 to 75% by weight, and more preferably 25 to 40% by weight of a polypropylene resin. It is preferable that the composition of the resin composition for the A layer is within the above range because generation of cutting waste can be suppressed in the dicing process of the semiconductor wafer.

  In addition to the copolymer of the vinyl aromatic hydrocarbon and the conjugated diene hydrocarbon or the polypropylene resin, the resin composition for the layer A contains known additives such as an antioxidant and a weather resistance agent. Can be included. Although it does not specifically limit as the addition range, It is preferable that it is 10 weight% or less in the resin composition for A layer, and the range of 1-5 weight% can be mentioned.

1.2 B layer B layer is an intermediate | middle layer which consists of a resin composition containing 0-20 weight% of polypropylene-type resins, and 100-80 weight% of olefin type thermoplastic elastomers.

(1) Polypropylene resin The polypropylene resin used in the B layer can be the same as that used in the A layer.

(2) Olefin-based thermoplastic elastomer The olefin-based thermoplastic elastomer used in the present invention preferably contains a polypropylene resin component and a copolymer rubber component of propylene and ethylene, and a polypropylene resin (matrix phase). An elastomer having a sea-island structure in which a copolymer rubber of propylene and ethylene is finely dispersed is more preferable.

  In the olefin thermoplastic elastomer, the polypropylene resin component is preferably 10 to 40% by weight, and more preferably 20 to 30% by weight. The copolymer rubber component of propylene and ethylene is preferably 60 to 90% by weight, and more preferably 70 to 80% by weight.

(I) Polypropylene resin component The polypropylene resin is preferably a propylene homopolymer having an isotactic index of 90% or more, and more preferably a propylene homopolymer having 95% or more. When the isotactic index of the polypropylene resin is less than 90%, the heat resistance of the olefin thermoplastic elastomer tends to be inferior.

(Ii) Copolymer rubber component of propylene and ethylene The copolymerization ratio of propylene and ethylene is not particularly limited and can be appropriately determined. As an example, propylene / ethylene = 10-90 / 90-10 (weight%) etc. can be mentioned, for example.

  The copolymer rubber may contain a copolymer component in addition to propylene and ethylene. Examples of the copolymer component include 1,4-hexadiene, 5-methyl-1,5-hexadiene, 1,4-octadiene, cyclohexadiene, cyclooctadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5 Non-conjugated dienes such as -butylidene-2-norbornene and 2-isopropenyl-5-norbornene can be mentioned. These addition amounts are not particularly limited, and can be added within a range not impairing the effects of the present invention.

  In the olefinic thermoplastic elastomer used in the present invention, the elution amount at 0 ° C. in the temperature rising elution fractionation between 0 ° C. and 140 ° C. using o-dichlorobenzene as a solvent is 60-80 with respect to the total elution amount. It is preferable that it is weight%. It is preferable that the elution amount at 0 ° C. is within this range because warpage can be effectively suppressed.

  Here, temperature rising elution fractionation (TREF) is a known analysis method. As a specific measuring method, for example, a method disclosed in JP-A-2003-7654 can be exemplified.

(Iii) Production method of olefinic thermoplastic elastomer The production method of the olefinic thermoplastic elastomer used in the present invention is not particularly limited, and any known method may be used. Indicates.

  In the first stage, propylene is supplied to the reaction vessel, the temperature is 50 to 150 ° C. (preferably 50 to 100 ° C.), and the partial pressure of propylene is 0.5 to 4.5 MPa (preferably 1. The polymerization of the propylene homopolymer is performed under the conditions of 0 to 3.5 MPa).

  Subsequently, in the second stage, propylene and ethylene are supplied, and in the presence of a catalyst, the temperature is 50 to 150 ° C. (preferably 50 to 100 ° C.), and propylene and ethylene partial pressures are each 0.3 to 4.5 MPa (preferably Is produced by polymerizing a propylene-ethylene copolymer under the conditions of 0.5 to 3.5 MPa).

(3) Resin composition for B layer The resin composition for B layer used for the dicing film of the present invention comprises 0 to 20% by weight of the polypropylene resin and 100 to 80% by weight of the olefinic thermoplastic elastomer. The resin preferably contains 0 to 10% by weight of the olefin resin and 90 to 100% by weight of the olefinic thermoplastic elastomer, and more preferably contains 0 to 5% by weight of the polypropylene resin and 95 to 100% by weight of the olefinic thermoplastic elastomer. . It is preferable that the composition of the resin composition for the B layer is within the above range because generation of cutting waste can be suppressed in the dicing process of the semiconductor wafer.

1.3 C layer C layer is composed of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof of 0 to 40% by weight and polypropylene resin of 100 to 60% by weight. Anti-blocking layer.

  Examples of the copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon used in the C layer or a hydrogenated product thereof, and the polypropylene-based resin include the same ones that can be used in the A layer.

  The resin composition for the C layer used in the dicing film of the present invention is a copolymer of the vinyl aromatic hydrocarbon and the conjugated diene hydrocarbon or a hydrogenated product thereof of 0 to 40% by weight and the polypropylene resin of 100 to 60% by weight. The vinyl aromatic hydrocarbon and conjugated diene hydrocarbon copolymer or hydrogenated product thereof is preferably 0 to 30% by weight and polypropylene resin 70 to 100% by weight. More preferably, it contains a copolymer of hydrogen and a conjugated diene hydrocarbon or a hydrogenated product thereof in an amount of 10 to 20% by weight and a polypropylene resin in an amount of 80 to 90% by weight. When the composition of the resin composition for the C layer is within the above range, blocking is preferably suppressed.

  The C layer may further contain an antistatic agent as necessary. As the antistatic agent used in the C layer, known surfactants such as anionic, cationic, and nonionic surfactants can be selected. In particular, from the viewpoint of durability and durability, polyether ester amide resins and hydrophilic polyolefins are used. Nonionic surfactants such as resins are suitable.

  Furthermore, an antiblocking agent or the like may be further added to the C layer as long as the effects of the present invention are not adversely affected. By adding an anti-blocking agent, blocking such as when the substrate film for dicing is rolled up is preferably suppressed. Examples of the anti-blocking agent include inorganic or organic fine particles.

1.4 Thickness of each layer The thickness of the substrate film for dicing should be thicker than the cutting depth of the dicing blade and can be easily wound into a roll, and is not particularly limited. However, for example, 50 to 300 μm is preferable, 60 to 250 μm is more preferable, and 70 to 200 μm is more preferable.

  Further, the ratio of the thickness of the A layer to the total thickness of the substrate film for dicing is preferably 5 to 40%, more preferably 5 to 30%, and the ratio of the thickness of the B layer is preferably 20 to 90%. It is more preferably 40 to 90%, and the ratio of the thickness of the C layer is usually preferably 5 to 40%, more preferably 5 to 30%.

  As a specific example of the substrate film for dicing, when the total thickness of the substrate film for dicing is 120 to 180 μm, the thickness of the layer A is 6 to 72 μm, preferably 6 to 54 μm. The thickness of the B layer is 24-162 μm, preferably 48-162 μm. The thickness of the C layer is 6 to 72 μm, preferably 6 to 54 μm.

  The total thickness of the A layer and the B layer needs to be thicker than the depth of the deepest part of the dicing blade incision, so that the incision of the dicing blade does not reach the C layer. By providing the A layer and the B layer having such a thickness, cutting scraps as a base film are hardly generated.

2. Manufacturing Method of Dicing Substrate Film The three-layer dicing substrate film of the present invention is manufactured by multilayer coextrusion molding of the resin composition for the A layer, B layer and C layer. Specifically, a resin composition for layer A comprising a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or a hydrogenated product thereof of 30 to 80% by weight and polypropylene resin of 70 to 20% by weight, polypropylene B layer resin composition containing 0 to 20% by weight of resin and 100 to 80% by weight of olefinic thermoplastic elastomer, and copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof 0 to 40 A resin composition for a C layer containing 100% by weight and 100% by weight of a polypropylene resin is manufactured by coextrusion molding in the order of A layer / B layer / C layer.

  The resin composition for the A layer, the B layer, and the C layer can be prepared by dry blending or melt-kneading a predetermined ratio of resin. The composition mentioned above can be used for the resin composition for A layer, B layer, and C layer.

  Moreover, in this invention, the resin composition for A layers and the resin composition for C layers can be made into the same composition.

  The above-mentioned resins for each layer are respectively supplied to the screw type extruder in this order, extruded from a multilayer T die at 180 to 225 ° C., and cooled while passing through a cooling roll at 50 to 70 ° C. Take it unstretched. Alternatively, the resin for each layer may be once obtained as pellets and then extruded as described above.

  The reason why the film is substantially unstretched at the time of taking is to effectively extend the film after dicing. This substantially non-stretching includes non-stretching or slight stretching that does not adversely affect the expansion of the dicing film. In general, the film may be pulled to such an extent that no sagging occurs during film take-up.

3. Dicing film The substrate film for dicing obtained as described above is coated with a known acrylic pressure-sensitive adhesive or the like on the film to form a pressure-sensitive adhesive layer, and if necessary, on the acrylic pressure-sensitive adhesive layer (pressure-sensitive adhesive layer) A mold release film is provided to manufacture a dicing film. That is, an acrylic pressure-sensitive adhesive layer and a release film are formed on the A layer of the substrate film for dicing.

  As the pressure-sensitive adhesive component used in the acrylic pressure-sensitive adhesive layer, known ones can be used. For example, the pressure-sensitive adhesive component described in JP-A No. 5-21234 can be used. A known release film is also used.

Specific examples of acrylic pressure-sensitive adhesives include acrylic polymers selected from homopolymers and copolymers having (meth) acrylic acid ester as the main constituent monomer unit, and other functional monomers And a mixture of these polymers. For example, (meth) acrylic acid ester includes ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, Glycidyl acrylate, 2-hydroxyethyl acrylate and the like can be preferably used. The molecular weight of the acrylic polymer is 1.0 × 10 ^{5 to} 10.0 × 10 ⁵ , and preferably 4.0 × 10 ^{5 to} 8.0 × 10 ⁵ .

  In addition, by including a radiation polymerizable compound in the pressure-sensitive adhesive layer as described above, the adhesive strength can be reduced by irradiating the pressure-sensitive adhesive layer with radiation after the wafer is cut and separated. As such a radiation polymerizable compound, for example, a low molecular weight compound having at least two photopolymerizable carbon-carbon double bonds in a molecule that can be three-dimensionally reticulated by light irradiation is widely used (for example, JP JP-A-60-196956, JP-A-60-223139, etc.).

  Specifically, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the like are used.

  Furthermore, in addition to the acrylate compounds as described above, urethane acrylate oligomers can also be used as the radiation polymerizable compound. The urethane acrylate oligomer is obtained by reacting an acrylate or methacrylate having a hydroxyl group with a terminal isocyanate urethane prepolymer obtained by reacting a polyol compound such as polyester type or polyether type with a polyvalent isocyanate compound. This urethane acrylate oligomer is a radiation polymerizable compound having at least one carbon-carbon double bond.

  Further, in the pressure-sensitive adhesive layer, in addition to the pressure-sensitive adhesive and the radiation-polymerizable compound as described above, a compound (such as a leuco dye) that is colored by radiation irradiation, a light-scattering inorganic compound powder, and abrasive grains, as necessary. (A particle size of about 0.5 to 100 μm), an isocyanate curing agent, a UV initiator, and the like can also be contained.

  The dicing film is usually obtained in a rolled state cut into a tape shape.

  Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples, but the present invention is not limited to these Examples.

Examples 1-9, Comparative Examples 1-6
(Manufacture of resin composition)
Each raw material shown in Table 1 was dry blended at the blending ratio shown in Table 1 to obtain a resin composition. In addition, the raw material described in Table 1 is as follows.

<Polypropylene resin>
Sun Allomer PC412A (propylene homopolymer, MFR: 2.3 g / 10 min (230 ° C.), melting point: 160 ° C., manufactured by Sun Allomer Co., Ltd.).

<Hydrogenated copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon>
SEBS (styrene-butadiene copolymer hydrogenated product, MD6945 (trade name), MFR: 3.0 g / 10 min (230 ° C.), manufactured by Kraton Polymer Japan Co., Ltd.)
SEPS (Styrene-isoprene copolymer hydrogenated product, Hibler 7311 (trade name), specific gravity: 0.89, MFR: 2.0 g / 10 min (230 ° C.), manufactured by Kuraray Co., Ltd.)

<Olefin-based thermoplastic elastomer>
Zelas ZT813 (a thermoplastic elastomer having a sea-island structure in which a copolymer resin of propylene and ethylene is finely dispersed in a polypropylene resin component, manufactured by Mitsubishi Chemical Corporation).
Zelas 7023 (a thermoplastic elastomer having a sea-island structure in which a copolymer resin of propylene and ethylene is finely dispersed in a polypropylene resin component, manufactured by Mitsubishi Chemical Corporation).

(Manufacture of substrate film for grinding)
The resin composition for A layer, the resin composition for B layer, and the resin composition for C were supplied in this order to a multilayer extruder having a barrel temperature of 180 to 220 ° C. It was extruded from a 230 ° C. T-die, cooled and solidified with a take-up roll having a set temperature of 40 ° C., and wound up in an unstretched state. The thickness of each layer of the obtained film is as shown in Table 1.

  About the film obtained in Examples 1-9 and Comparative Examples 1-6, it evaluated by the following evaluation method. The results are shown in Table 1.

Evaluation method (measurement of film thickness of each layer)
In any part of the multilayer film obtained in Examples 1 to 9 and Comparative Examples 1 to 6, five measurement samples were taken from five places in the width direction. About each measurement sample, the total thickness of the film was measured using the micrometer.

  Thereafter, each measurement sample was cut with a microtome so that the cross section of the film could be observed. The cross section of the film was observed with a polarizing microscope, and the thickness ratio of the A layer to the C layer was measured. Each thickness of the A layer to the C layer was calculated from the total thickness of the measurement sample and the thickness ratio of each layer. The average value was calculated | required about the thickness of each layer measured from five measurement samples.

(Evaluation method of cutting waste)
A part of the multilayer film obtained in Examples 1 to 9 and Comparative Examples 1 to 6 was cut into a circular shape with a diameter of 180 mm to obtain a measurement sample, and a grinding apparatus (manufactured by DISCO Corporation AUTOMATIC DICING SAW DAD). -2H / 6), and the substrate film was cut under the following conditions.
Cutting conditions;
Rotation speed: 30,000rpm
Speed: 80mm / sec
Cut mode: Full auto dicing cut depth of 10mm □: 100μm
Blade: B1A801 SDC 400N50M51 manufactured by Disco Corporation (outer diameter 56 mm x thickness 0.2 mm x inner diameter 40 mm)
Water volume: 1.2L / min

Next, after removing the sample from the grinding device and drying it at room temperature in a clean booth for 24 hours, using a digital microscope (VHX-100, manufactured by Keyence Co., Ltd.), evaluate the presence or absence of cutting waste at a magnification of 150 times. went. The evaluation was performed by observing the surface of the sample arbitrarily at 10 locations and evaluating according to the following evaluation criteria.
○: No cutting waste.
X: It is recognized that there is even a small amount of cutting waste.

(Expanding evaluation method)
The obtained substrate film for dicing sheet is cut into a size of 300 mm × 300 mm to obtain a sample piece. Next, lines are put in a 10 mm × 10 mm grid on the entire surface of the sample piece. Two frames with a hole with a diameter of 200 mm are prepared in the center, and the test piece is sandwiched between them so that the positions of the holes are exactly overlapped, and fixed so that the test piece does not move. Then, this frame is fixed horizontally. A cylinder having an outer diameter of 150 mm and an inner diameter of 140 mm is set on the lower side of the frame and at the center of the hole. Next, the sample is expanded by pushing up the cylinder by 40 mm at a speed of 200 cm / min. Then, the longitudinal and lateral lengths of the lattice positioned in the center in this pushed-up state are measured, the respective elongation (%) with respect to the original sample is obtained, and the ratio of the elongation is calculated, The evaluation criteria were evaluated.
○: Ratio is 1.3 or less (extensibility is excellent).
X: Ratio exceeds 1.3 (no expandability).

(Blocking evaluation method)
Two samples for measurement were measured from an arbitrary position of the obtained dicing sheet substrate film to a size of 100 mm × 30 mm wide (the sample was cut out with the film flow direction as the vertical direction and the width direction as the horizontal direction). Cut out. Two measurement samples are placed so that the same surface (surface in contact with the cooling roll) overlaps with an area of 40 mm × 30 mm wide, and the overlapped measurement samples are sandwiched between two glass plates, from above A 600 g weight was placed on the part where the samples overlapped. This was placed in a constant temperature bath at 40 ° C. and left for 7 days. Seven days later, the sample taken out from the thermostatic chamber was set in a peel tester (Peeling TESTER HEIDON-17) manufactured by Shinto Kagaku Co., Ltd., and the 180 degree shear peel strength was measured at a pulling rate of 200 mm / min. When the measured value was 4.9 N / 10 mm or less, no blocking was considered.

Claims (4)

A substrate film for dicing laminated in the order of A layer / B layer / C layer,
The layer A consists of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof in an amount of 30 to 80% by weight and a polypropylene resin of 70 to 20% by weight,
B layer consists of a resin composition containing 0 to 20% by weight of a polypropylene resin and 100 to 80% by weight of an olefin thermoplastic elastomer,
Layer C is composed of a resin composition containing a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof of 0 to 40% by weight and polypropylene resin of 100 to 60% by weight,
Base film for dicing. The total thickness of the substrate film for dicing is 50 to 300 μm, the thickness of the A layer is 5 to 40%, and the thickness of the B layer is 20 to 90% with respect to the total thickness of the substrate film for dicing. The substrate film for dicing according to claim 1, wherein A dicing film further comprising an adhesive layer on the A layer of the substrate film for dicing according to claim 1. A method for producing a substrate film for dicing laminated in the order of A layer / B layer / C layer, comprising a copolymer of vinyl aromatic hydrocarbon and conjugated diene hydrocarbon or hydrogenated product thereof in an amount of 30 to 80% by weight And a layer A resin composition comprising 70 to 20% by weight of a polypropylene resin,
B-layer resin composition containing 0 to 20% by weight of a polypropylene resin and 100 to 80% by weight of an olefinic thermoplastic elastomer, and a copolymer of a vinyl aromatic hydrocarbon and a conjugated diene hydrocarbon or a hydrogenated product thereof 0 A resin composition for the C layer containing -40 wt% and polypropylene resin 100-60 wt%,
A production method comprising co-extrusion molding in the order of A layer / B layer / C layer.