Thermoplastic resin film, self-adhesive film, and self-adhesive film for semiconductor manufacturing process

Abstract

To provide a film which is not only excellent in film handleability and expandability during semiconductor manufacturing processes but also can reduce cutting debris generated from the film cut by a blade when a semiconductor wafer or a wafer in a package form in which a circuit is formed is cut into individual chips using a dicing blade, thereby enabling to suppress defects caused by the cutting debris, the film also having good appearance, and also to provide a self-adhesive film which can be suitably used for semiconductor manufacturing processes by providing an adhesive layer on the film.SOLUTION: A thermoplastic resin film comprises at least three layers, i.e. a surface layer, a backside layer and a middle layer. The surface layer and / or the backside layer, and the middle layer contain an olefin-based elastomer. The middle layer further contains 15-35 mass% of a styrene-based resin to 100 mass% of a thermoplastic resin included in the middle layer, and the thermoplastic resin film has a tensile elongation at break of 400-600%.

Description

[Technical field]

[0001] The present invention relates to an adhesive film (tape) used in the semiconductor manufacturing process, a decorative adhesive film (tape) such as a sticker, label or marking film attached to a signboard, an automobile or the like to impart design, or a thermoplastic resin film suitable for use as a substrate for decorative sheets, etc., an adhesive film using said thermoplastic resin film, and an adhesive film for the semiconductor manufacturing process. [Background technology]

[0002] Conventionally, polyvinyl chloride resin films (hereinafter also referred to as "PVC-based films") have been widely used as the substrate for adhesive films (tapes) used in the semiconductor manufacturing process, decorative adhesive films (tapes) such as stickers, labels and marking films attached to signs, automobiles, etc. to add design features, and decorative sheets, etc., as they are thermoplastic resin films with excellent colorability, processability, scratch resistance, weather resistance, etc.

[0003] The PVC film itself has rigidity, but a plasticizer is added to impart flexibility so that the film can function as an adhesive film. However, depending on the plasticizer used, the film may have poor compatibility with the adhesive, resulting in poor stability when used as an adhesive film, and the plasticizer may bleed out significantly. In addition, there is a tendency for restrictions on the use of plasticizers to be strengthened. Therefore, films using polyolefin resins have come to be widely used as thermoplastic resin films to replace PVC films.

[0004] Furthermore, in the process of manufacturing semiconductors, adhesive films for semiconductor wafer processing are used when cutting semiconductor wafers, packages, etc., and due to the above-mentioned problems that arise when using PVC-based films, the use of polyolefin-based resin films is increasingly being used. As films for such semiconductor manufacturing processes, films using PVC-based and polyolefin-based resins have been developed (for example, Patent Document 1).

[0005] In recent years, semiconductor elements have become smaller and thinner. In addition to the need for films that are easy to handle and flexible when expanding, there are cases where a reduction in cutting waste is generated from the film when a dicing blade is used to separate semiconductor wafers or packaged wafers with circuits formed into chips.

[0006] Patent Document 2 discloses a substrate film for use in semiconductor manufacturing processes that is provided with antistatic properties and has excellent flexibility and heat resistance. Moreover, Patent Document 3 discloses a film that is excellent in rigidity and characterized by its breaking elongation.

[0007] However, although the film described in Patent Document 2 has excellent antistatic properties and heat resistance, there is no mention of reducing cutting waste from the film, and it is presumed that there is room for improvement. In addition, although Patent Document 3 describes a film characterized by its breaking elongation, it is presumed to have high rigidity and poor expandability and handling properties, and there is thought to be room for improvement for use in semiconductor manufacturing processes. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 09-008111 [Patent Document 2] JP 2020-84143 A [Patent Document 3] Patent Publication No. 2021-195481 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0009] In view of the above problems, the present invention aims to provide a film that is not only excellent in handleability and expandability in the semiconductor manufacturing process, but also reduces cutting waste generated from the film cut by a dicing blade when a semiconductor wafer or a packaged wafer having a circuit formed thereon is diced into chips using a dicing blade, thereby suppressing defects caused by the cutting waste. Another aim of the present invention is to provide an adhesive film that can be suitably used in the semiconductor manufacturing process by providing an adhesive layer on the film. [Means for solving the problem]

[0010] The present inventors have conducted extensive research into films for solving the above problems and have completed the present invention.

[0011] That is, the gist of the present invention is as follows. [1] A thermoplastic resin film consisting of at least three layers: a surface layer, a back layer, and an intermediate layer, The front layer and / or the back layer contain an olefin-based elastomer, and the intermediate layer contains 15 to 35 mass% of a styrene-based resin relative to 100 mass% of the thermoplastic resin contained in the intermediate layer; A thermoplastic resin film having a tensile elongation at break of 400 to 600%. [2] The thermoplastic resin film according to [1], wherein the intermediate layer contains 50 to 80 mass % of an olefin-based elastomer and a styrene-based resin in total relative to 100 mass % of the thermoplastic resin contained in the intermediate layer. [3] The thermoplastic resin film according to [1] or [2], wherein the front layer and the back layer contain an olefin-based elastomer, and the content of the olefin-based elastomer contained in the intermediate layer is greater than the content of the olefin-based elastomer contained in the front layer and the back layer. [4] The thermoplastic resin film according to [1] or [2], further comprising a styrene-based elastomer. [5] The thermoplastic resin film according to [1] or [2], wherein the tensile elongation at break of a film consisting only of an olefin-based elastomer is 600% or less. [6] A thermoplastic resin film according to [1] or [2], in which the tensile elongation at break of a film consisting only of a styrene-based resin is 100% or less. [7] An adhesive film having an adhesive layer on at least one surface of the thermoplastic resin film of [1] or [2]. [8] [7] An adhesive film for the semiconductor manufacturing process using the adhesive film. Effect of the Invention

[0012] By using the thermoplastic resin film of the present invention, not only is the film excellent in handleability and expandability in the semiconductor manufacturing process, but also when a semiconductor wafer or a packaged wafer having a circuit formed thereon is diced into chips using a dicing blade, the amount of cutting waste generated from the film cut by the blade can be reduced, and defects caused by the cutting waste can be suppressed, and a film having a good appearance can be provided. In addition, by providing a pressure-sensitive adhesive layer on the film, it is also possible to provide a pressure-sensitive adhesive film that can be suitably used in the semiconductor manufacturing process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be modified and practiced in various ways within the scope of the gist. In addition, when the expression "~" is used in this specification, it is used as an expression including the numerical value or physical property value before and after it.

[0014] One embodiment of the present invention is a thermoplastic resin film consisting of at least three layers consisting of a front layer, a back layer, and an intermediate layer, the front layer and / or back layer and the intermediate layer contain an olefin-based elastomer, and the intermediate layer further contains 15 to 35 mass% of a styrene-based resin relative to 100 mass% of the thermoplastic resin contained in said layer; The thermoplastic resin film has a tensile elongation at break of 400 to 600%.

[0015] The thermoplastic resin film of the present invention contains an olefin-based elastomer and a styrene-based resin as essential components for the purpose of adjusting flexibility and the tensile elongation at break of the film. By containing a predetermined amount of the styrene-based resin, it is possible to reduce the elongation at break of the obtained film. Therefore, even when the film is cut using a dicing blade, it is easy to break the film before it forms fibrous cutting chips, and it is possible to suppress the generation of fibrous cutting chips caused by the contact and stretching of the blade and the film. As a component other than the olefin-based elastomer and the styrene-based resin, a polyolefin-based resin is preferably used. By using the polyolefin-based resin, the compatibility with the olefin-based elastomer is improved. Furthermore, even when the styrene-based resin is used, a significant decrease in the breaking elongation can be suppressed, and a film with excellent handling properties can be obtained, so that a film with excellent appearance and handling properties can be obtained.

[0016] As the polyolefin resin, a polypropylene resin or a polyethylene resin is preferably used. Examples of polypropylene-based resins include homopolymers of propylene (homopolypropylene), copolymers containing propylene as the main component and other monomers copolymerizable with propylene, and mixtures of these.

[0017] Examples of the copolymers containing propylene as a main component and other monomers copolymerizable with propylene include random copolymers (random polypropylenes) and block copolymers (block polypropylenes) of propylene and ethylene or other α-olefins, and block or graft copolymers containing a rubber component.

[0018] The α-olefin used as the other monomer copolymerizable with propylene preferably has 4 to 12 carbon atoms, and examples thereof include 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, and 1-decene. One or a mixture of two or more of these is used.

[0019] The polypropylene resin preferably has a crystalline melting peak of 120° C. or higher. By having a crystalline melting peak of 120° C. or higher, it is possible to impart sufficient heat resistance to the obtained film. The crystalline melting peak is more preferably 125° C. or higher, and even more preferably 130° C. or higher. From the viewpoints of availability, heat resistance and flexibility, it is preferable to use homopolypropylene, random polypropylene and block polypropylene among the above polypropylene-based resins, and it is more preferable to use homopolypropylene and random polypropylene.

[0020] Commercially available homopolypropylene products include, for example, Novatec PP "MA3U" and Novatec PP "FY6HA" (both manufactured by Japan Polypropylene Corporation), PC600A, PC600S, PL500A, PLA00A (all manufactured by SunAllomer Co., Ltd.), WF836DG3, FLX80H5 (all manufactured by Sumitomo Chemical Co., Ltd.), F-113Q, and F-704NP (all manufactured by Prime Polypropylene Co., Ltd.). Commercially available random polypropylene products include, for example, Novatec PP "FW4BA" and Novatec PP "FX3B" (both manufactured by Japan Polypropylene Corporation), PC630A, PC630S (both manufactured by SunAllomer Corporation), F-730NV, and F-744NP (both manufactured by Prime Polypropylene Corporation). The polypropylene resin may be used alone or in combination of two or more kinds. It can be appropriately selected as necessary in consideration of film-forming properties when obtaining a thermoplastic resin film, and flexibility, handling properties, and expandability of the obtained film.

[0021] Examples of polyethylene resins include ethylene homopolymers, copolymers of ethylene with other monomers copolymerizable with ethylene, which are mainly composed of ethylene (low-density polyethylene (LDPE), high-pressure low-density polyethylene, linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), ethylene copolymers obtained by polymerization using a metallocene catalyst (metallocene-based polyethylene), ethylene-vinyl acetate copolymers, ethylene-methyl (meth)acrylate copolymers, ethylene-ethyl (meth)acrylate copolymers, ethylene-butyl (meth)acrylate copolymers, ethylene-(meth)acrylic acid copolymers, and metal ion crosslinked resins (ionomers) of ethylene-(meth)acrylic acid copolymers. Among these, those containing metal ions may cause failures or defects in semiconductor wafers or circuits formed on the wafers due to the influence of the metal ions, so it is preferable not to use those that intentionally contain metal ions. From the viewpoints of ease of availability, ease of handling of the resin, and ease of adjusting the flexibility of the resulting film, it is preferable to use high density polyethylene (HDPE), low density polyethylene (LDPE), or linear low density polyethylene (LLDPE).

[0022] Commercially available high density polyethylene products include, for example, Novatec HD "HF560" and Novatec HD "HF562" (both manufactured by Japan Polyethylene Corporation), F371, and B161 (both manufactured by Asahi Kasei Corporation). Commercially available low-density polyethylene products include, for example, Novatec LD "LC500", Novatec LD "LC520", Novatec LD "LC720" (all manufactured by Japan Polyethylene Co., Ltd.), F224N, F324C, F522N (all manufactured by Ube Maruzen Polyethylene Co., Ltd.), and the like. Commercially available linear low-density polyethylene products include, for example, Novatec LL "UF420" and Novatec LL "UF641" (both manufactured by Japan Polyethylene Co., Ltd.), Yumerit "0540F", and Yumerit "4040F" (both manufactured by Ube Maruzen Polyethylene Co., Ltd.). The polyethylene resin may be used alone or in combination of two or more kinds. It can be appropriately selected as necessary in consideration of the film-forming properties when obtaining a film, and the flexibility, handling properties, and expandability of the obtained film.

[0023] The melt flow rate of polypropylene resins and polyethylene resins is appropriately selected depending on the molding method and application, but it is preferable that the value measured under a temperature condition of 190°C or 230°C and a load of 2.16 kg is 0.1 to 50 g / 10 min. If it is 0.1 g / 10 min or more, the moldability of the film is good, and if it is 50 g / 10 min or less, the thickness precision of the film can be maintained at a good level. It is more preferable that it is 0.5 to 40 g / 10 min, and even more preferable that it is 1.0 to 30 g / 10 min.

[0024] Regarding the strength of the polypropylene-based resin and the polyethylene-based resin, the tensile modulus of a film obtained from these resins alone is preferably within the range of 50 to 2000 MPa. If the tensile modulus is within the range of 50 to 2000 MPa, it is possible to impart appropriate flexibility to the film of the present invention. It is more preferably within the range of 50 to 1500 MPa, and even more preferably within the range of 50 to 1000 MPa.

[0025] The olefin-based elastomer used as an essential component in the present invention is a soft resin containing a polyolefin-based resin and a rubber component, and may be one in which the rubber component is dispersed in the polyolefin-based resin, or one in which the two are copolymerized with each other.

[0026] Specific examples of olefin-based elastomers include amorphous elastic copolymers mainly composed of olefins, such as ethylene-propylene copolymer elastomers, ethylene-1-butene copolymer elastomers, ethylene-propylene-1-butene copolymer elastomers, ethylene-1-hexene copolymer elastomers, ethylene-1-octene copolymer elastomers, ethylene-styrene copolymer elastomers, ethylene-norbornene copolymer elastomers, propylene-1-butene copolymer elastomers, ethylene-propylene-non-conjugated diene copolymer elastomers, ethylene-1-butene-non-conjugated diene copolymer elastomers, and ethylene-propylene-1-butene-non-conjugated diene copolymer elastomers, as well as derivatives and acid-modified derivatives thereof.

[0027] It is preferable to use an olefin-based elastomer that exhibits a tensile breaking elongation of 600% or less when the film is made only of the olefin-based elastomer (i.e., a film obtained from the olefin-based elastomer alone). By using an olefin-based elastomer with a tensile breaking elongation of 600% or less, the handleability of the resulting thermoplastic resin film is not impaired, and it is possible to reduce cutting waste generated from the film cut by a dicing blade when a semiconductor wafer or a packaged wafer having a circuit formed thereon is diced into chips using a dicing blade. It is more preferable that the elongation is 550% or less, and even more preferable that the elongation is 500% or less.

[0028] The melt flow rate of the olefin elastomer is appropriately selected depending on the molding method and application, but is preferably 0.1 to 50 g / 10 min, measured under a temperature condition of 190°C or 230°C and a load of 2.16 kg. If it is 0.1 g / 10 min or more, the moldability of the film is good, and if it is 50 g / 10 min or less, the thickness precision of the film can be maintained at a good level. It is more preferably 0.5 to 40 g / 10 min, and even more preferably 1.0 to 30 g / 10 min.

[0029] Regarding the strength of the olefin-based elastomer, the tensile modulus of a film consisting of only the olefin-based elastomer is preferably within the range of 20 to 800 MPa. If the tensile modulus is within the range of 20 to 800 MPa, it is possible to impart appropriate flexibility to the film of the present invention. It is more preferably within the range of 20 to 600 MPa, and even more preferably within the range of 20 to 400 MPa. The tensile elongation at break and tensile modulus of olefin-based elastomers are measured using a monolayer film consisting of only the olefin-based elastomer as a test piece, with reference to JIS K 7127. Measurements are performed in the extrusion direction (MD) of the film and / or in the direction perpendicular to the extrusion direction (TD). The device used for the measurement is not particularly limited as long as it can perform the measurement under similar conditions, and any commonly available tensile testing device can be used.

[0030] Commercially available olefin-based elastomers include, for example, TAFMER "BL2491M", TAFMER "BL2481M", ABSOTMER "EP1001", and ABSOTMER "EP1013" (all manufactured by Mitsui Chemicals, Inc.). The olefin-based elastomer may be used alone or in combination of two or more kinds. It can be appropriately selected as necessary in consideration of film-forming properties when obtaining a thermoplastic resin film, flexibility and handling properties of the obtained film, and reduction effect of cutting waste.

[0031] In addition, from the viewpoint of imparting flexibility to the thermoplastic resin film of the present invention and of film formability when obtaining a film, an olefin-based elastomer other than the olefin-based elastomers described above may also be added to the thermoplastic resin film of the present invention. Commercially available examples of the olefin-based elastomer include Wellnex "RFX4V", Wellnex "RFG4VM", Wellnex "RMG02" (all manufactured by Japan Polypropylene Corporation), and Cattalloy "C200F" (all manufactured by SunAllomer Corporation). The olefin-based elastomer may be used alone or in combination of two or more kinds. It can be appropriately selected as necessary in consideration of film-forming properties when obtaining a thermoplastic resin film, flexibility and handling properties of the obtained film, and reduction effect of cutting waste.

[0032] In addition to the olefin elastomer, it is essential that a styrene-based resin is added to the intermediate layer of the thermoplastic resin film of the present invention. Furthermore, the intermediate layer must contain 15 to 35 mass % of a styrene-based resin that satisfies the following, relative to 100 mass % of the thermoplastic resin contained in the layer. As described above, by using a styrene-based resin, it is possible to reduce the breaking elongation of the resulting film. Furthermore, when the content of the styrene-based resin is 15% by mass or more, it is possible to sufficiently reduce the breaking elongation of the obtained film, and by setting it to 35% by mass or less, it is possible to prevent the breaking elongation of the obtained film from being excessively reduced, and to suppress deterioration of the appearance of the film due to compatibility, thereby making it possible to maintain a good appearance. The tensile elongation at break of a film made only of a styrene-based resin (that is, a film obtained solely from a styrene-based resin) is preferably 100% or less, more preferably 80% or less, and even more preferably 60% or less. The content of the styrene-based resin in the intermediate layer is more preferably within the range of 15 to 33 mass%, and even more preferably within the range of 15 to 31 mass%, relative to 100 mass% of the thermoplastic resin in the layer. Regarding the strength of the styrene resin, the tensile modulus of a film consisting of only the styrene resin is preferably within the range of 1000 to 4000 MPa. If the tensile modulus is within the range of 1000 to 4000 MPa, it is easy to maintain the flexibility of the film of the present invention. It is more preferably within the range of 1000 to 3700 MPa, and even more preferably within the range of 1000 to 3400 MPa. The tensile elongation at break and the tensile modulus of elasticity of the styrene-based resin can be measured by the same method as described above.

[0033] As the styrene-based resin, one which gives a tensile elongation at break of 100% or less when made of only the styrene-based resin is preferable, and a commercially available resin can be appropriately selected and used. Examples of types of styrene-based resins include general-purpose polystyrene (GPPS), high impact polystyrene (HIPS), styrene-α-methylstyrene copolymer, styrene-p-methylstyrene copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-maleic anhydride copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylonitrile copolymer, etc. Among these, from the viewpoints of availability and economy, it is preferable to use general-purpose polystyrene and high impact polystyrene. Commercially available general-purpose polystyrene products include, for example, "HF77", "679", and "SGP10" (all manufactured by PS Japan Co., Ltd.). Commercially available impact-resistant polystyrene products include, for example, "H9152", "408", and "HT478" (all manufactured by PS Japan). In addition, the styrene resin used in the present invention is contained in the intermediate layer as an essential component, but it can also be contained in at least one of the front and back layers. By containing the styrene resin in the front and back layers, it becomes easier to reduce cutting waste. However, since the styrene resin has poor compatibility with the above-mentioned polyolefin resin and olefin elastomer, when the styrene resin is contained in the front and back layers, there is a possibility that defects such as the adhesion of the resin to the T-die during film formation may occur, which deteriorates the appearance of the film. Therefore, from the viewpoint of reducing cutting waste and suppressing defects such as the adhesion of the resin, it is preferable to contain the above-mentioned styrene resin in the range of 0 to 30 mass% in 100 mass% of the thermoplastic resin in the resin composition constituting each of the front and back layers. More preferably, it is in the range of 0 to 25 mass%, and even more preferably, it is in the range of 0 to 20 mass%.

[0034] The thermoplastic resin film of the present invention may contain a styrene-based elastomer for the purposes of imparting flexibility, reducing cutting debris, and maintaining a good appearance of the film by improving compatibility with the above-mentioned olefin-based elastomers and other polyolefin-based resins. The styrene-based elastomer is preferably a block copolymer represented by the following formula (I) or (II). X-(YX)n …(I) (XY)n …(II) In general formulas (I) and (II), X is an aromatic vinyl polymer block (hereinafter, styrene component) typified by styrene, and in formula (I), the degree of polymerization at both ends of the molecular chain may be the same or different. Y is at least one selected from a butadiene polymer block, an isoprene polymer block, a butadiene / isoprene copolymer block, a hydrogenated butadiene polymer block, a hydrogenated isoprene polymer block, a hydrogenated butadiene / isoprene copolymer block, a partially hydrogenated butadiene polymer block, a partially hydrogenated isoprene polymer block, and a partially hydrogenated butadiene / isoprene copolymer block. n is an integer of 1 or more.

[0035] Specific examples of styrene-based elastomers include styrene-ethylene-butylene-styrene copolymers, styrene-ethylene-propylene-styrene copolymers, styrene-ethylene-ethylene-propylene-styrene copolymers, styrene-butadiene-butene-styrene copolymers, styrene-butadiene-styrene copolymers, styrene-isoprene-styrene copolymers, styrene-hydrogenated butadiene diblock copolymers, styrene-hydrogenated isoprene diblock copolymers, styrene-butadiene diblock copolymers, styrene-isoprene diblock copolymers, etc., among which styrene-ethylene-butylene-styrene copolymers, styrene-ethylene-propylene-styrene copolymers, styrene-ethylene-ethylene-propylene-styrene copolymers, and styrene-butadiene-butene-styrene copolymers are preferred. Also usable are block copolymers that are styrene-ethylene-butylene-crystalline olefin copolymers.

[0036] The melt flow rate of the styrene elastomer (measured at a temperature of 230°C under a load of 2.16 kg) is preferably 0.1 to 10 g / 10 min, more preferably 0.15 to 9 g / 10 min, and particularly preferably 0.2 to 8 g / 10 min. If the melt flow rate of the styrene elastomer is 0.1 g / 10 min or more and 10 g / 10 min or less, it has good compatibility with the above-mentioned resin and is preferable in terms of film formability.

[0037] There is no particular restriction on the content of the styrene component in the styrene-based elastomer, and it can be appropriately selected and used within a range that does not impair the flexibility, breaking elongation, or appearance of the resulting film. When it is necessary to impart flexibility to the film, it is preferable to use one having a styrene component content of 40% by mass or less. When it is necessary to further reduce the decrease in the breaking elongation of the film and the generation of cutting chips when cutting, it is preferable to use one having a styrene component content of 40% by mass or more. The content of styrene components and other components is as follows: 1 H-NMR and 13It can be measured by C-NMR. Here, the "styrene component content" refers to the content ratio (mass%) of aromatic vinyl polymer blocks, typically styrene, based on the mass of the styrene-based elastomer.

[0038] Commercially available styrene-based elastomers having a styrene content of 40% or less include, for example, Tuftec H1221, Tuftec H1062, Tuftec H1052, Tuftec P1083 (all manufactured by Asahi Kasei Corporation), Hybler 7311, Hybler 7311F (all manufactured by Kuraray Co., Ltd.), and the like. Commercially available styrene-based elastomers having a styrene content of 40% or more include, for example, Tuftec H1051, Tuftec H1517, Tuftec H1043 (all manufactured by Asahi Kasei Corporation), Septon 2104 (all manufactured by Kuraray Co., Ltd.), and Dynaron 9901P (all manufactured by JSR Corporation).

[0039] The styrene-based elastomer may be used alone or in combination of two or more kinds. It can be appropriately selected as necessary in consideration of film-forming properties when obtaining a thermoplastic resin film, flexibility and handling properties of the obtained film, and reduction effect of cutting waste.

[0040] <Other resins> In addition to the above-mentioned olefin-based elastomers, styrene-based resins, polypropylene-based resins, polyethylene-based resins, and styrene-based elastomers, other resins may be added to the thermoplastic resin film of the present invention as long as the heat resistance and flexibility are not impaired. Examples of other resins include cyclic olefin-based resins and polymethylpentene-based resins. Examples of cyclic olefin resins include norbornene polymers, vinyl alicyclic hydrocarbon polymers, and cyclic conjugated diene polymers. Among these, norbornene polymers are preferred. Examples of norbornene polymers include ring-opening polymers of norbornene monomers and norbornene copolymers obtained by copolymerizing norbornene monomers with α-olefins such as ethylene. Hydrogenated products of these may also be used.

[0041] As the polymethylpentene-based resin, it is preferable to use a homopolymer having methylpentene as a monomer or a copolymer with other monomers.Specific examples include a copolymer of α-olefin and 4-methylpentene-1, which are exemplified as other monomers copolymerizable with propylene for the polypropylene-based resin. When the polymethylpentene resin is a copolymer, the content of the α-olefin component used in the copolymerization is preferably 20% by mass or less. By making it 20% by mass or less, it is possible to suppress the decrease in the crystal melting peak. It is more preferably 10% by mass or less.

[0042] <Other ingredients> The thermoplastic resin film of the present invention may contain various additives in order to impart antistatic properties, heat resistance, weather resistance, and the like. Specific examples of the additives that may be used include antistatic agents, antioxidants, neutralizing agents, lubricants, antiblocking agents, plasticizers, heat stabilizers, light stabilizers, dyes and pigments, crystal nucleating agents, ultraviolet absorbers, fillers, inorganic fillers that impart rigidity, and elastomers other than those mentioned above that impart flexibility, within the scope of not impairing the effects of the present invention.

[0043] As the polymer-type antistatic agent, a known one can be used, for example, a block copolymer of a hydrophobic block and a hydrophilic block can be used. In the polymer-type antistatic agent, the hydrophobic block and the hydrophilic block form a block copolymer through ester bonds, ether bonds, amide bonds, imide bonds, urethane bonds, urea bonds, etc.

[0044] As the ultraviolet absorbing agent, known agents can be used, and examples thereof include benzotriazole-based ultraviolet absorbing agents, benzophenone-based ultraviolet absorbing agents, and triazine-based ultraviolet absorbing agents.

[0045] As the light stabilizer, a known one can be used, and examples thereof include hindered amine light stabilizers.

[0046] As the lubricant or antiblocking agent, it is preferable to use a silicone-olefin copolymer, since this has excellent compatibility with the above-mentioned polypropylene-based resins, polyethylene-based resins, etc., and makes it possible to prevent defects due to bleed-out on the surface of the obtained film and to impart long-term scratch resistance and slipperiness.

[0047] <Thermoplastic resin film> The thermoplastic resin film of the present invention is a thermoplastic resin film consisting of at least three layers, namely a surface layer, a back layer, and an intermediate layer, in which the surface layer and / or the back layer and the intermediate layer contain an olefin-based elastomer, and the intermediate layer contains 15 to 35 mass% of a styrene-based resin relative to 100 mass% of the thermoplastic resin contained in said layer, and the tensile elongation at break of the thermoplastic resin film is 400 to 600%. By containing a predetermined amount of olefin-based elastomer and styrene-based resin in a predetermined layer, it is possible to reduce the breaking elongation of the obtained film, and therefore, even when the film is cut with a dicing blade, it is easy to break the film before it forms fibrous cutting chips, and it is possible to suppress the generation of fibrous cutting chips caused by the contact and stretching of the film with the blade. In addition, it is possible to obtain a film having a good appearance without impairing the appearance of the obtained film.

[0048] The thermoplastic resin film of the present invention comprises at least three layers: a front layer, a back layer, and an intermediate layer. Since one side of either the front or back layer is cut by a dicing blade, it is necessary for at least the layer on the side to be cut to contain an olefin-based elastomer. It is necessary to incorporate an olefin-based elastomer into at least one of the surfaces of the front layer and the back layer, but from the viewpoint of film-forming properties and economic efficiency when obtaining a film, it may be incorporated into either one of the surfaces or both. In addition, by forming a film consisting of at least three layers, it is possible to give characteristics to each of the front layer, back layer, and intermediate layer, and it is easy to adjust the characteristics to be given to only one of the layers. Furthermore, the intermediate layer may be composed of two or more layers. In that case, the obtained thermoplastic film will have a film composition consisting of four or more layers.

[0049] The thickness of each of the surface layer, back layer, and intermediate layer is preferably within the range of 1 to 20% of the total thickness of the thermoplastic resin film, and the intermediate layer is preferably within the range of 60 to 98%. By setting the thickness of each of the surface layer, back layer, and intermediate layer within the above range, it becomes possible to stably produce a film consisting of multiple layers. More preferably, the surface layer and back layer are within the range of 2 to 18%, and the intermediate layer is within the range of 64 to 96%, and even more preferably, the surface layer and back layer are within the range of 4 to 16%, and the intermediate layer is within the range of 68 to 92%.

[0050] The thermoplastic resin film of the present invention must contain an olefin-based elastomer and a styrene-based resin in 100% by mass of the thermoplastic resin in the resin composition constituting the intermediate layer, and it is essential that the styrene-based resin is contained in an amount of 15 to 35% by mass. Furthermore, the total amount of the olefin-based elastomer and the styrene-based resin in 100% by mass of the thermoplastic resin in the resin composition constituting the intermediate layer is preferably within the range of 50 to 80% by mass. By making the total amount 50% by mass or more, it is possible to sufficiently reduce the breaking elongation, and by making it 80% by mass or less, it is preferable that the breaking elongation is reduced without deteriorating the appearance of the obtained film. The more preferable range of the total amount is 53 to 77% by mass, and the even more preferable range is 56 to 74% by mass.

[0051] It is preferable that the surface layer and / or back layer and the intermediate layer each contain an olefin-based elastomer, and further, it is preferable that the intermediate layer contains more polyolefin-based elastomer than the surface layer and / or back layer. By containing more olefin-based elastomer in the intermediate layer, it becomes easier to adjust the breaking elongation of the obtained film and reduce cutting waste.

[0052] The surface layer and / or back layer preferably contains 50-90% by mass of polyolefin resin, 10-40% by mass of olefin elastomer (α), and 0-30% by mass of other thermoplastic resins, based on 100% by mass of the thermoplastic resin contained in these layers. By containing the thermoplastic resins used in the above-mentioned ratios, it is possible to reduce the adhesion of the film to the transport roll when forming the film, and it is also easy to suppress blocking between films. More preferably, the polyolefin resin is 60-95% by mass, the olefin elastomer (α) is 5-35% by mass, and the other thermoplastic resin is 0-35% by mass, and even more preferably, the polyolefin resin is 70-100% by mass, the olefin elastomer (α) is 0-30% by mass, and the other thermoplastic resin is 0-30% by mass. Here, the type and content of each resin component in each resin composition constituting the front layer and / or back layer may be the same or different.

[0053] Furthermore, it is preferable that the content of the olefin-based elastomer in the resin composition constituting the intermediate layer is greater than the content of the olefin-based elastomer in the resin compositions constituting the front and back layers. By making the intermediate layer contain a large amount of the olefin-based elastomer, it becomes easy to impart the effect of reducing cutting waste while adjusting various physical properties of the obtained film, and it becomes possible to stably produce a film consisting of multiple layers.

[0054] The thermoplastic resin film of the present invention may contain the above-mentioned styrene-based elastomer for the purpose of imparting flexibility, reducing cutting waste, and improving the compatibility of the obtained film to improve the appearance. The styrene-based elastomer is preferably contained in the intermediate layer. In this case, the intermediate layer preferably contains 0 to 40% by mass of the styrene-based elastomer relative to 100% by mass of the thermoplastic resin contained in the layer, more preferably 0 to 35% by mass, and even more preferably 0 to 30% by mass. The styrene-based elastomer may also be contained in at least one of the surface layer and the back layer. In this case, the surface layer and / or the back layer preferably contains 0 to 30% by mass of the styrene-based elastomer relative to 100% by mass of the thermoplastic resin contained in these layers. By containing the styrene-based elastomer in the surface layer and the back layer, it becomes easy to impart flexibility to the obtained film, but if it is contained in too much, the surface layer and the back layer become too flexible, which increases the possibility of problems such as deterioration of processability and blocking between films. The content in the surface layer and the back layer is more preferably in the range of 0 to 25% by mass, and even more preferably in the range of 0 to 20% by mass. The type and content of the styrene-based elastomer in each of the resin compositions constituting the front layer and the back layer may be the same or different.

[0055] The total thickness of the thermoplastic resin film of the present invention is preferably 30 to 250 μm. If it is 30 μm or more, the film formability during film production and the handleability of the obtained film are good, and if it is 250 μm or less, the handleability and processability of the film in the process of laminating a printing layer or an adhesive layer on the film can be kept good. The thickness of the film of the present invention is more preferably 40 to 200 μm, and further preferably 50 to 150 μm.

[0056] The tensile elongation at break of the thermoplastic resin film of the present invention is preferably within the range of 400 to 600%. By setting the tensile elongation at break within the range of 400 to 600%, defects due to breakage can be suppressed even when the film is subjected to adhesion processing or the like, and cutting waste when the film is cut with a dicing blade can be reduced. It is more preferably within the range of 400 to 580%, and even more preferably within the range of 400 to 560%.

[0057] Furthermore, the tensile modulus of the thermoplastic resin film of the present invention is preferably within the range of 100 to 700 MPa. If it is within the range of 100 to 700 MPa, the film is not too flexible and can maintain good handleability. It is more preferably within the range of 120 to 680 MPa, and even more preferably within the range of 140 to 660 MPa.

[0058] The film of the present invention can be formed by any known method, but it is preferable to use a melt extrusion method. Among the melt extrusion methods, a T-die molding method in which a molten resin is extruded from an extruder having a T-die and cooled and solidified to obtain a film is more preferable.

[0059] In order to obtain a film, it is preferable to use a co-extrusion T-die molding method using a plurality of extruders. By using a co-extrusion T-die molding method using a plurality of extruders, it is possible to obtain a multi-layer film, and the resin composition used in the surface layer of the present invention can be used only on one side or both sides. In addition, the resin compositions used in the surface layer, back layer, and intermediate layer can all be the same, and a film of substantially a single layer can be obtained. It is more preferable to use a film consisting of at least three layers consisting of the surface layer, back layer, and intermediate layer, because it is easy to impart the tensile elongation at break, tensile modulus, and other functions to the obtained film.

[0060] Examples of coextrusion T-die molding methods include a method in which multiple resin layers are formed into a film using a multi-manifold die, and then the layers are brought into contact inside the T-die to form a multi-layered film; and a method in which multiple resins are joined and bonded together using a device that joins molten resins called a feed block, to obtain a multi-layered film. If necessary, one or both sides of the film may be subjected to a surface treatment such as a plasma treatment, a corona treatment, an ozone treatment, a flame treatment, etc. Depending on the application of the resulting film, it is possible to select whether to perform the surface treatment on one or both sides.

[0061] <Adhesive film> The thermoplastic resin film of the present invention can be made into an adhesive film by providing an adhesive layer on at least one of the front and back surfaces (hereinafter also referred to as "adhesive film of the present invention"). The adhesive used in the adhesive layer is not particularly limited, and various adhesives such as natural rubber resins, acrylic resins, styrene resins, silicone resins, polyvinyl ether resins, etc. may be used. In addition, a functional layer such as an adhesive layer or a thermosetting resin layer may be further provided on the adhesive layer.

[0062] The pressure-sensitive adhesive layer can be provided by directly coating the pressure-sensitive adhesive on the thermoplastic resin film, or by laminating the pressure-sensitive adhesive layer on a separator or the like having a release layer, and attaching the pressure-sensitive adhesive layer side of the separator to the surface layer of the thermoplastic resin film of the present invention, thereby transferring the pressure-sensitive adhesive layer. In the pressure-sensitive adhesive film of the present invention, one or both sides of the film may be subjected to the above-mentioned surface treatment before the pressure-sensitive adhesive layer is provided. In addition, a primer layer may be provided between the film and the pressure-sensitive adhesive layer, if necessary.

[0063] The thickness of the adhesive layer and the primer layer can be appropriately determined according to need. The film of the present invention not only has excellent handleability and expandability, but also reduces cutting debris generated from the film cut by a dicing blade when a semiconductor wafer or a packaged wafer having circuits formed thereon is diced into chips using a dicing blade, thereby making it possible to suppress defects caused by the cutting debris. Furthermore, it is also possible to obtain an adhesive film by laminating an adhesive layer on the film, and the adhesive film can be suitably used in the semiconductor manufacturing process. EXAMPLES

[0064] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The materials used in the following examples and comparative examples and the methods for measuring the evaluated properties are as follows.

[0065] [Materials used] As the thermoplastic resin, a polypropylene-based resin, a polyethylene-based resin, an olefin-based elastomer, and a styrene-based elastomer were used as shown below.

[0066] <Random polypropylene> SunAllomer Corporation, "PC630A" (random polypropylene, melt flow rate at 230°C and 2.16 kg: 7.5 g / 10 min, crystal melting peak: 135°C, tensile modulus of single film: 600 MPa) <Homopolypropylene> Sumitomo Chemical Co., Ltd., "FLX80H5" (homopolypropylene, melt flow rate at 230°C and 2.16 kg: 8.0 g / 10 min, crystal melting peak: 162°C, tensile modulus of single film: 900 MPa) <Olefin elastomer (α)> Mitsui Chemicals, Inc., "Toughmer BL2491M" (olefin elastomer, melt flow rate at 230°C and 2.16 kg: 9.0 g / 10 min, crystal melting peak: 100°C, tensile modulus of single film: 230 MPa, tensile elongation at break of single film: 450%) <Olefin elastomer (γ)> Wellnex RFG4VM, manufactured by Japan Polypropylene (olefin elastomer, melt flow rate at 230°C and 2.16 kg: 6.0 g / 10 min, crystal melting peak: 127°C, tensile modulus of single film: 240 MPa, tensile elongation at break of single film: 750%) <Styrene-based resin (β)> PS Japan Co., Ltd., "HF77" (general-purpose polystyrene (GPPS), melt flow rate at 200°C and 5 kg: 7.5 g / 10 min, tensile modulus of single film: 2000 MPa, tensile elongation at break of single film: 40%) <Styrene-based elastomer> Asahi Kasei Corporation's "Tuftec H1221" (Melt flow rate at 230°C and 2.16 kg: 4.5 g / 10 min, styrene content: 12% by mass, styrene-ethylene-butylene-styrene copolymer)

[0067] <Preparation of Resin Composition> The above thermoplastic resins were mixed so that the total amount was 100 parts by mass. When two or more types were used, they were mixed by dry blending, and it was confirmed by visual inspection that the mixture was homogeneous.

[0068] <Film production method> Each resin composition was charged into each hopper of three Toshiba Machine single screw extruders (surface layer: 35φmm, L / D=25mm, middle layer: 50φmm, L / D=32, back layer: 35φmm, L / D=25mm), the extruder temperature of each extruder was set to 1900-230°C, and the three-layer structure of surface layer / middle layer / back layer was merged in the feed block section and extruded from a 650mm wide T-die (temperature setting 210-230°C, lip opening 0.5mm). The rotation speed of each extruder was set so that the thickness configuration was as shown in Table 1. The extruded molten resin was cooled and solidified on a winding machine equipped with a mirror-like cooling roll (cooling roll 700 mm wide x φ350 mm, roll temperature approximately 30°C), after which corona treatment was performed on both sides and the resin was wound up to obtain a multilayer film consisting of two types and three layers with a thickness of approximately 80 μm. In the present invention, the mirror-finished surface of the obtained film facing the cooling roll is referred to as the surface layer. In addition, the single resin films were essentially single-layer films consisting of three layers of one type, and the thickness was set to 80 μm.

[0069] [Thickness of each layer] The thickness of each layer was calculated from the amount of resin extruded from each extruder.

[0070] [Total film thickness] The thickness of the film was measured at the center and both ends using a contact thickness meter to confirm that the film had the desired thickness.

[0071] [Film appearance] The appearance of the film during film formation and the appearance of the obtained film were visually observed and evaluated according to the following criteria. ◎: No irregularities or other abnormalities in appearance during film formation or in the resulting film ○: Although it was thinly observed during film formation, there was no significant abnormality in the appearance of the film △: Thinly observed during film formation, and slight abnormalities observed in the film ×: Significant irregularities such as unevenness are observed during film formation and on the film.

[0072] [Tensile modulus] Test pieces were taken from the obtained multilayer film using a dumbbell "SDK-600" manufactured according to JISK6732, and the tensile modulus (MPa) was measured at a tension speed of 50 mm / min using an autograph (Shimadzu Corporation AGS-X) under the following conditions referring to JISK7127, 23°C, 50% RH atmosphere. The tensile modulus was measured in the extrusion direction (MD) of the film.

[0073] [Tensile elongation at break] Test pieces were taken from the obtained film using a dumbbell "SDK-600" manufactured in accordance with JIS K6732, and the tensile breaking elongation (%) was measured at a tensile speed of 300 mm / min using a small tabletop testing machine (Shimadzu EZ-L) in an atmosphere of 23°C and 50% RH. The tensile elongation at break was measured in the extrusion direction (MD) of the film. Moreover, the same measurement method as above was also carried out on films of each resin alone.

[0074] [Example 1] The thermoplastic resins used for the surface layer, intermediate layer and back layer were random polypropylene, homopolypropylene, olefin-based elastomer (α), styrene-based resin (β) and styrene-based elastomer. The blending amounts of each resin were as shown in Table 1 to prepare resin compositions. The tensile breaking elongation of the film consisting only of the olefin-based elastomer (α) was 450%, and the tensile breaking elongation of the film consisting only of the styrene-based resin (β) was 40%. Using each of the above resin compositions, a film consisting of two types and three layers with a total thickness of 80 μm was obtained by the above-mentioned film-forming method. The film-forming conditions were adjusted so that the thickness of each layer was 4 μm for the surface layer, 72 μm for the middle layer, and 4 μm for the back layer. No defects such as unevenness were found in the appearance of the obtained film, and it was confirmed that the film had a good appearance. In addition, this film contains an olefin-based elastomer (α) with a tensile breaking elongation of 600% or less in the front layer, back layer, and middle layer, and further contains 16% by mass of a styrene-based resin (β) in the middle layer, so the tensile breaking elongation of the obtained film is 550%, which is a sufficiently low breaking elongation. Furthermore, since the tensile modulus is 250 MPa, it is confirmed that the film has sufficient flexibility and good handleability. Therefore, since a sufficient reduction in tensile breaking elongation was confirmed for this film, it was confirmed that the generation of cutting debris is suppressed even when cut with a dicing blade, and the film has excellent handleability with a good appearance and flexibility.

[0075] [Example 2] The same procedure as in Example 1 was carried out except that the olefin-based elastomer (α) and styrene-based resin (β) for the intermediate layer were as shown in Table 1. No defects such as unevenness were found in the appearance of the obtained film, and it was confirmed that the film had a good appearance. In addition, this film contains an olefin-based elastomer (α) with a tensile breaking elongation of 600% or less in the front layer, back layer, and middle layer, and further contains 20% by mass of a styrene-based resin (β) in the middle layer, so the tensile breaking elongation of the obtained film is 570%, which confirmed that the film has a sufficiently low breaking elongation. Furthermore, since the tensile modulus is 290 MPa, it was confirmed that the film has sufficient flexibility and good handleability. Therefore, since a sufficient reduction in tensile breaking elongation was confirmed for this film, it was confirmed that the generation of cutting debris is suppressed even when cut with a dicing blade, and the film has excellent handleability with a good appearance and flexibility.

[0076] [Example 3] The same procedure as in Example 1 was carried out except that the olefin-based elastomer (α) and styrene-based resin (β) for the intermediate layer were as shown in Table 1. No defects such as unevenness were found in the appearance of the obtained film, and it was confirmed that the film had a good appearance. In addition, this film contains an olefin-based elastomer (α) with a tensile breaking elongation of 600% or less in the front layer, back layer, and middle layer, and further contains 26% by mass of a styrene-based resin (β) in the middle layer, so the tensile breaking elongation of the obtained film is 550%, which is a sufficiently low breaking elongation. Furthermore, since the tensile modulus is 410 MPa, it is confirmed that the film has sufficient flexibility and good handleability. Therefore, since a sufficient reduction in tensile breaking elongation was confirmed for this film, it was confirmed that the generation of cutting debris is suppressed even when cut with a dicing blade, and the film has excellent handleability with a good appearance and flexibility.

[0077] [Example 4] The same procedure as in Example 1 was carried out except that the olefin-based elastomer (α) and styrene-based resin (β) for the intermediate layer were as shown in Table 1. Although slight unevenness was observed during film formation to obtain the film, no significant abnormalities were observed in the appearance of the obtained film, and therefore it is presumed that the film can be used without any problems. In addition, this film contains an olefin-based elastomer (α) with a tensile elongation at break of 600% or less in the front layer, back layer, and middle layer, and further contains 30% by mass of a styrene-based resin (β) in the middle layer, so the tensile elongation at break of the obtained film is 500%, which confirmed that the film has a sufficiently low elongation at break. Furthermore, since the tensile modulus is 520 MPa, it was confirmed that the film has sufficient flexibility and good handleability. Therefore, since a sufficient reduction in tensile elongation at break was confirmed for this film, it was confirmed that the generation of cutting debris is suppressed even when cut with a dicing blade, and the film has an excellent appearance and is flexible and easy to handle.

[0078] [Comparative Example 1] The same procedure as in Example 1 was carried out except that the homopolypropylene, the olefin-based elastomer (α), the styrene-based resin (β), and the styrene-based elastomer in the intermediate layer were as shown in Table 1. No defects such as unevenness were found in the appearance of the obtained film, and it was confirmed that the film had a good appearance. In addition, this film contains an olefin-based elastomer (α) with a tensile elongation at break of 600% or less in the front layer, back layer, and middle layer, but the middle layer contains only 12% by mass of styrene-based resin (β), so the tensile elongation at break of the obtained film was 610%, and a sufficient decrease in the elongation at break was not confirmed. Since the tensile modulus was 310 MPa, it was confirmed that the film had sufficient flexibility and was easy to handle. Therefore, although this film has a good appearance and flexibility and is considered to be easy to handle, it is presumed that the tensile elongation at break is not sufficiently reduced, and the generation of cutting debris cannot be sufficiently suppressed when cut with a dicing blade.

[0079] [Comparative Example 2] Random polypropylene, homopolypropylene and olefin-based elastomer (γ) were used as the thermoplastic resins for the surface layer, intermediate layer and back layer. The resin compositions were prepared with the blending amounts of each resin as shown in Table 1. The tensile breaking elongation of the film consisting only of the olefin-based elastomer (γ) was 750%. Using each of the above resin compositions, a film consisting of two types and three layers with a total thickness of 80 μm was obtained by the above-mentioned film-forming method. The film-forming conditions were adjusted so that the thickness of each layer was 4 μm for the surface layer, 72 μm for the middle layer, and 4 μm for the back layer. This film has a tensile modulus of elasticity of 390 MPa and is considered to have excellent handling properties. However, since the intermediate layer does not contain an olefin-based elastomer (α) with a tensile elongation at break of 600% or less, and does not contain a styrene-based resin (β), the tensile elongation at break of the film is 760%, and no decrease in the elongation at break is observed. Therefore, although this film has a good appearance and flexibility and is considered to be easy to handle, it is presumed that this film is unable to sufficiently suppress the generation of cutting debris when cut with a dicing blade.

[0080] [Comparative Example 3] The same procedure as in Example 1 was carried out except that the olefin-based elastomer (α) and styrene-based resin (β) for the intermediate layer were as shown in Table 1. Unevenness was observed during film formation to obtain the film, and the unevenness was also significantly observed in the obtained film. Therefore, it is presumed that the film has a poor appearance and is highly likely to cause defects due to its appearance when used in the semiconductor manufacturing process. Therefore, it was confirmed that although this film contains an olefin-based elastomer (α) and a styrene-based resin (β) and is expected to be effective in reducing cutting debris, it has a poor appearance and is therefore likely to cause problems due to its appearance.

[0081] [Comparative Example 4] The same procedure as in Example 1 was repeated, except that the thermoplastic resins for the surface layer, intermediate layer and back layer were random polypropylene, homopolypropylene, olefin-based elastomer (γ) and styrene-based resin (β) as shown in Table 1. No defects such as unevenness were found in the appearance of the obtained film, and it was confirmed that the film had a good appearance. In addition, although this film contains 25% by mass of styrene-based resin (β) in the middle layer, the surface layer and middle layer contain olefin-based elastomer (γ) with a tensile breaking elongation of 600% or more, so the tensile breaking elongation of the obtained film was 630%, and a sufficient decrease in breaking elongation was not confirmed. Since the tensile modulus was 770 MPa, it is presumed that the film does not have sufficient flexibility. Furthermore, since it is thought that the compatibility between the styrene-based resin (β) and other resins is insufficient, faint unevenness was observed in the appearance of the obtained film, and it was confirmed that the appearance was also poor. Therefore, this film is inferior in flexibility, handleability, and appearance, and no sufficient decrease in tensile elongation at break is observed, so it is presumed that this film is unable to sufficiently suppress the generation of cutting debris when cut with a dicing blade.

[0082] [Table 1]

[0083] [Example 5] An acrylic adhesive (SK Dyne 1502C manufactured by Soken Chemical Industries, Ltd.) was applied onto the separator using the comma coat method so that the adhesive layer would be 25 μm thick after drying, and the adhesive layer was then dried for 5 minutes in a hot air dryer at 80°C to form an adhesive layer. The adhesive layer side of the prepared separator was attached to the surface of the outer layer side of the film obtained in Example 1 to obtain an adhesive film of the present invention in which the film and the adhesive layer were laminated. It is presumed that by using this adhesive film as an adhesive film for the semiconductor manufacturing process, the generation of cutting debris is suppressed even when this adhesive film is cut with a dicing blade, making it possible to suppress defects caused by cutting debris during the semiconductor manufacturing process. [Industrial Applicability]

[0084] According to the present invention, not only is the film excellent in handleability and expandability in the semiconductor manufacturing process, but also when a semiconductor wafer or a packaged wafer having a circuit formed thereon is diced into chips using a dicing blade, the amount of cutting waste generated from the film cut by the blade can be reduced, and defects caused by the cutting waste can be suppressed, and a film having a good appearance can be provided. In addition, by providing a pressure-sensitive adhesive layer on the film, it is also possible to provide a pressure-sensitive adhesive film that can be suitably used in the semiconductor manufacturing process.

Claims

1. A thermoplastic resin film consisting of at least three layers, which are a surface layer, a back layer, and an intermediate layer, The surface layer and / or the back layer and the intermediate layer contain an olefin-based elastomer, Further, the intermediate layer contains 15 to 35% by mass of a styrene-based resin relative to 100% by mass of the thermoplastic resin contained in the intermediate layer, A thermoplastic resin film having a tensile elongation at break of 400 to 600%.

2. 2. The thermoplastic resin film according to claim 1, wherein the intermediate layer contains 50 to 80 mass % of an olefin-based elastomer and a styrene-based resin in total relative to 100 mass % of the thermoplastic resin contained in the intermediate layer.

3. The front and back layers contain an olefin-based elastomer, 3. The thermoplastic resin film according to claim 1, wherein the content of the olefin-based elastomer in the intermediate layer is greater than the content of the olefin-based elastomer in the front layer and / or back layer.

4. The thermoplastic resin film according to claim 1 or 2, further comprising a styrene-based elastomer.

5. 3. The thermoplastic resin film according to claim 1, wherein the tensile elongation at break of a film consisting of the olefin-based elastomer alone is 600% or less.

6. 3. The thermoplastic resin film according to claim 1, wherein the tensile elongation at break of a film consisting of a styrene-based resin is 100% or less.

7. 3. An adhesive film comprising the thermoplastic resin film according to claim 1 or 2 and an adhesive layer on at least one surface of the film.

8. An adhesive film for use in semiconductor manufacturing processes, comprising the adhesive film according to claim 7 .

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