Thermoplastic resin films, adhesive films, and adhesive films for semiconductor manufacturing processes

Abstract

The object of the present invention is to provide a film that is not only easy to handle and expandable, but also has excellent heat resistance and handling properties, and is suitable for semiconductor manufacturing processes that do not involve an expansion process and require heat resistance and suppression of cutting debris. In such processes, the film reduces the amount of cutting debris generated from the film when cutting various materials, including semiconductor wafers and package-shaped wafers with circuits formed on them, into chip-shaped pieces, and also has excellent heat resistance and handling properties. [Solution] A substrate film for semiconductor manufacturing processes comprising at least one layer made of a resin composition containing a polyolefin resin and a styrene elastomer, A base film having a tensile modulus of elasticity of 450 MPa or more and 800 MPa or less, and a tensile elongation at break of 650% or less.

Description

Technical Field

[0001] The present invention relates to a thermoplastic resin film suitably used as a base material for adhesive films (tapes) used in semiconductor manufacturing processes, decorative adhesive films (tapes) such as stickers, labels and marking films to be attached for imparting design properties to signboards, automobiles and the like, or decorative sheets, as well as an adhesive film using the thermoplastic resin film and an adhesive film for semiconductor manufacturing processes.

Background Art

[0002] Conventionally, as thermoplastic resin films excellent in colorability, processability, scratch resistance, weather resistance and the like, films made of polyvinyl chloride resin (hereinafter also referred to as "PVC-based films") have been widely used as base materials for adhesive films (tapes) used in semiconductor manufacturing processes, decorative adhesive films (tapes) such as stickers, labels and marking films to be attached for imparting design properties to signboards, automobiles and the like, decorative sheets and the like.

[0003] The PVC-based films themselves have rigidity, but plasticizers are added for the purpose of imparting flexibility so that they can function as adhesive films. However, depending on the plasticizer used, there are problems such as poor compatibility with the adhesive, poor stability when made into an adhesive film, and significant bleed-out of the plasticizer. In addition, there is a tendency for regulations on the use of plasticizers themselves to become stricter. Accordingly, films using polyolefin-based resins have been widely used as thermoplastic resin films replacing PVC-based films.

[0004] Also, in processes for manufacturing semiconductors, adhesive films for processing semiconductor wafers are used when cutting semiconductor wafers, packages and the like, and the number of cases where polyolefin-based resin films are used is increasing due to the above-mentioned problems that occur when PVC-based films are used. As such films for semiconductor manufacturing processes, films using PVC-based or polyolefin-based resins have been developed (for example, Patent Document 1).

[0005] In recent years, semiconductor devices have become smaller and thinner, and in addition to the handling and flexibility required for expansion of films, there is a need to reduce the amount of cutting debris generated from the film when semiconductor wafers or packaged wafers with circuits formed on them are cut into individual chips using dicing blades. Furthermore, cases of cutting materials other than wafers are also being observed, and there is an increasing need to design films tailored to each material and process, such as not performing expansion or requiring heat resistance depending on the material being cut and the subsequent processes.

[0006] Patent Document 2 discloses a substrate film for semiconductor manufacturing processes that provides antistatic properties and is excellent in flexibility and heat resistance, while Patent Document 3 discloses a film that is excellent in rigidity and has good elongation at break. Furthermore, Patent Document 4 proposes a film that has excellent expandability and can suppress cutting debris.

[0007] However, while the film described in Patent Document 2 has excellent antistatic properties and heat resistance, it does not mention reducing cutting debris from the film, suggesting that there is room for improvement. Furthermore, while Patent Document 3 is presumed to have high rigidity and excellent heat resistance, there is room for improvement in its elongation at break, and it is also thought that its excessively high modulus of elasticity may result in poor handling of the film. Although the film described in Patent Document 4 is presumed to have excellent expandability and elongation at break, there is room for improvement in order to achieve all physical properties such as a certain degree of rigidity, heat resistance, and suppression of cutting chips. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 09-008111 [Patent Document 2] Japanese Patent Publication No. 2020-84143 [Patent Document 3] Japanese Patent Publication No. 2021-195481 [Patent Document 4] Japanese Patent Publication No. 2024-18386 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0009] In view of the above problems, the present invention aims to provide a film that reduces cutting debris generated from a film cut by a blade when individualizing various materials, not just semiconductor wafers and package-shaped wafers with circuits formed on them, into chip-shaped pieces, in a semiconductor manufacturing process that does not have an expansion process and requires heat resistance and suppression of cutting debris, and that also has excellent heat resistance and handling properties. Furthermore, the present invention also aims to provide an adhesive film that can be suitably used in semiconductor manufacturing processes by providing an adhesive layer on the film. [Means for solving the problem]

[0010] The inventors of this invention have diligently studied films composed of resin compositions containing polyolefin resins and styrene elastomers, and as a result have completed this invention.

[0011] In other words, the gist of this invention is as follows: [1] A substrate film for semiconductor manufacturing processes comprising at least one layer made of a resin composition (A) containing a polyolefin resin and a styrene elastomer, A base film having a tensile modulus of elasticity of 450 MPa or more and 800 MPa or less, and a tensile elongation at break of 650% or less. [2] It consists of at least three layers: a surface layer, a back layer, and an intermediate layer. At least the intermediate layer is a layer made of the resin composition (A), The intermediate layer contains 50 to 95% by mass of polyolefin resin, 5 to 50% by mass of styrene elastomer, and 0 to 20% by mass of other resins, based on 100% by mass of the resin composition (A), as described in [1], for a substrate film for semiconductor manufacturing processes. [3] The surface layer and the back layer are layers made of a resin composition (B), and each layer contains 80 to 100% by mass of a polyolefin resin and 0 to 20% by mass of a styrene elastomer based on 100% by mass of the resin composition (B), as described in [2], for a semiconductor manufacturing process substrate film. [4] A substrate film for semiconductor manufacturing processes according to any one of [1] to [3], wherein the polyolefin resin is a polypropylene resin and / or a polyethylene resin. [5] A substrate film for semiconductor manufacturing processes according to any one of [1] to [4], wherein the styrene content of the styrene-based elastomer is 40% by mass or more. [6] The semiconductor manufacturing process substrate film according to any one of [1] to [5], wherein the polyolefin resin is one or more selected from the group consisting of a homopolymer of propylene and a random copolymer of propylene and ethylene or other α-olefins. [7] The resin composition (A) contains, as a polyolefin resin, at least one propylene homopolymer and at least one propylene and ethylene or other α-olefin random copolymer, A substrate film for semiconductor manufacturing processes according to any one of [1] to [6], wherein the ratio of the total content of propylene homopolymers to the total content of the random copolymers is 80:20 to 50:50. [8] An adhesive film having an adhesive layer on at least one side of a substrate film for semiconductor manufacturing processes as described in any one of items [1] to [7]. [9] [8] An adhesive film for semiconductor manufacturing processes comprising the adhesive film described above. [Effects of the Invention]

[0012] By using the film of the present invention, in a semiconductor manufacturing process that does not include an expanding step and requires heat resistance and suppression of cutting debris, when various other materials are singulated into chips, not only semiconductor wafers and package-shaped wafers with circuits formed thereon, it is possible to reduce cutting debris generated from the film cut by a blade, and to provide a film excellent in heat resistance and handleability. Further, according to the present invention, by providing an adhesive layer on the film, it is also possible to provide an adhesive film that can be suitably used for semiconductor manufacturing processes. [Modes for Carrying Out the Invention]

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

[0014] 1. Base film for semiconductor manufacturing process The present invention is a base film for semiconductor manufacturing processes, which comprises at least one layer composed of a resin composition (A) containing a polyolefin-based resin and a styrene-based elastomer, wherein the film has a tensile modulus of 450 MPa or more and 800 MPa or less, and a tensile elongation at break of 650% or less (hereinafter also referred to as "the film of the present invention").

[0015] The film of the present invention contains the below-described polyolefin-based resin and styrene-based elastomer as essential components for the purpose of adjusting the elastic modulus and the tensile elongation at break of the film. The resin composition containing the polyolefin-based resin and the styrene-based elastomer is hereinafter also referred to as "resin composition (A)". By setting the tensile modulus of the film to between 450 MPa and 800 MPa, it becomes easier to suppress problems with handling and process passability caused by the film being too flexible or too rigid. Furthermore, by setting the elongation at break of the film to 650% or less, it becomes easier to reduce the amount of cutting debris generated when cutting the film or the adhesive film for semiconductor manufacturing processes using the film with a blade.

[0016] The details of each item regarding the semiconductor manufacturing process substrate film of the present invention are described below.

[0017] (1) Polyolefin resins Polypropylene resins and polyethylene resins are preferably used as polyolefin resins for the film of the present invention. Examples of polypropylene resins include homopolymers of propylene (homopolypropylene), copolymers of propylene as the main component with other monomers copolymerizable with propylene, and mixtures thereof.

[0018] Copolymers of propylene as the main component with other monomers copolymerizable with propylene include random copolymers (random polypropylene) and block copolymers (block polypropylene) of propylene and ethylene or other α-olefins, as well as block copolymers or graft copolymers containing rubber components.

[0019] As other monomers copolymerizable with propylene, α-olefins having 4 to 12 carbon atoms are preferred, such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, and 1-decene, and one or more of these can be used.

[0020] The crystal melting peak of the polypropylene resin is preferably 120°C or higher. Having a crystal melting peak of 120°C or higher makes it possible to impart sufficient heat resistance to the resulting film. More preferably 125°C or higher, and even more preferably 130°C or higher. From the viewpoint of availability, heat resistance, and rigidity, it is preferable to use homopolypropylene, random polypropylene, or block polypropylene among the above-mentioned polypropylene resins, and more preferably homopolypropylene or random polypropylene. In particular, it is preferable to use homopolypropylene that exhibits a crystal melting peak of 150°C or higher from the viewpoint of providing heat resistance and rigidity.

[0021] Examples of commercially available homopolypropylene products include Novatec PP "MA3U", Novatec PP "FY6HA" (both manufactured by Nippon Polypropylene Co., Ltd.), PC600A, PC600S, PL500A, PLA00A (all manufactured by Sun Allomer Co., Ltd.), WF836DG3, FLX80H5 (both manufactured by Sumitomo Chemical Co., Ltd.), F-113Q, F-704NP (both manufactured by Prime Polypropylene Co., Ltd.). Examples of commercially available random polypropylene products include Novatec PP "FW4BA" and Novatec PP "FX3B" (both manufactured by Nippon Polypropylene Co., Ltd.), PC630A and PC630S (both manufactured by Sun Allomer Co., Ltd.), and F-730NV and F-744NP (both manufactured by Prime Polypropylene Co., Ltd.). The above-mentioned polypropylene resins may be used individually or in combination of two or more types. They can be appropriately selected as needed, taking into consideration factors such as film-forming properties, heat resistance, handling properties, and elastic modulus of the resulting film.

[0022] Examples of polyethylene resins include ethylene homopolymers, copolymers of ethylene as the main component with other monomers copolymerizable with ethylene, such as low-density polyethylene (LDPE), high-pressure low-density polyethylene, linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), ethylene copolymers obtained by polymerization using metallocene catalysts (metallocene polyethylene), ethylene-vinyl acetate copolymer, ethylene-(meth)acrylate copolymer, ethylene-(meth)acrylate ethyl copolymer, ethylene-(meth)acrylate butyl copolymer, ethylene-(meth)acrylate copolymer, and metal ion crosslinked resins (ionomers) of ethylene-(meth)acrylate copolymers. Among these, those containing metal ions are preferable not to use, as the influence of these metal ions may cause failures or malfunctions in semiconductor wafers or circuits formed on the wafers. From the viewpoint of ease of availability, ease of handling of the resin, and ease of adjusting the elastic modulus of the resulting film, it is preferable to use high-density polyethylene (HDPE), low-density polyethylene (LDPE), or linear low-density polyethylene (LLDPE).

[0023] Examples of commercially available high-density polyethylene include Novatec HD "HF560", Novatec HD "HF562" (both manufactured by Nippon Polyethylene Co., Ltd.), F371, and B161 (both manufactured by Asahi Kasei Corporation). Examples of commercially available low-density polyethylene include Novatec LD "LC500", Novatec LD "LC520", Novatec LD "LC720" (all manufactured by Nippon Polyethylene Co., Ltd.), F224N, F324C, F522N (all manufactured by Ube Maruzen Polyethylene Co., Ltd.). Examples of commercially available linear low-density polyethylene include Novatec LL "UF420" and Novatec LL "UF641" (both manufactured by Nippon Polyethylene Co., Ltd.), and Yumerit "0540F" and Yumerit "4040F" (both manufactured by Ube Maruzen Polyethylene Co., Ltd.). The polyethylene resins mentioned above may be used individually or in combination of two or more types. They can be appropriately selected as needed, taking into consideration factors such as film-forming properties, heat resistance, handling characteristics, and elastic modulus of the resulting film.

[0024] The melt flow rate of polypropylene-based resins and polyethylene-based resins is appropriately selected depending on the molding method and application, but it is preferable that the value measured at a temperature of 190°C or 230°C with 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 will be good, and if it is 50 g / 10 min or less, it will be possible to maintain good thickness accuracy of the film. More preferably it is 0.5 to 40 g / 10 min, and even more preferably 1.0 to 30 g / 10 min.

[0025] Regarding the strength of the polypropylene-based resin and polyethylene-based resin, it is preferable that the tensile modulus of the film obtained from these resins alone is in the range of 200 to 2000 MPa. If the tensile modulus is in the range of 200 to 2000 MPa, it is possible to impart appropriate rigidity to the film of the present invention. More preferably, it is in the range of 250 to 1500 MPa, and even more preferably in the range of 300 to 1000 MPa.

[0026] In addition to the polyolefin resin described above, the present invention also allows for the addition of olefin elastomers to the extent that they do not impair the physical properties of the film. Olefin elastomers are soft resins comprising a polyolefin resin and a rubber component, and the rubber component may be dispersed in the polyolefin resin, or they may be copolymerized together. However, the film of the present invention must contain a polyolefin resin and a styrene elastomer, which will be described later. When the olefin elastomer is added to the resin composition (A), its content in 100% by weight of the resin composition (A) is 0 to 30% by weight, preferably 0 to 20% by weight, and more preferably 0% by weight (not contained).

[0027] 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 their derivatives and acid-modified derivatives. Examples of commercially available olefin-based elastomers include Toughmer "BL2491M", Toughmer "BL2481M", Absortomer "EP1001", Absortomer "EP1013" (all manufactured by Mitsui Chemicals), Cataloy "C200F" (both manufactured by Sun Allomer), and Vistamax "Vistamaxx6202" (both manufactured by ExxonMobil). Olefin-based elastomers may be used individually or in combination of two or more types. They can be appropriately selected as needed, taking into consideration the film-forming properties when obtaining thermoplastic resin films, the flexibility and handling properties of the resulting films, and the effect of reducing cutting debris.

[0028] In one preferred embodiment of the film of the present invention, the polyolefin resin contained in the resin composition (A) is a polypropylene resin and / or a polyethylene resin.

[0029] In another preferred embodiment of the film of the present invention, the polyolefin resin contained in the resin composition (A) is one or more selected from the group consisting of a propylene homopolymer and a random copolymer of propylene and ethylene or other α-olefins.

[0030] In another, more preferred embodiment of the film of the present invention, the resin composition (A) contains, as a polyolefin resin, at least one propylene homopolymer and at least one random copolymer of propylene and ethylene or other α-olefin, wherein the ratio of the total content of propylene homopolymers to the total content of the random copolymers is 80:20 to 50:50. By setting the ratio of the total content of propylene homopolymers to the total content of the random copolymers within the above range, it becomes easier to adjust the elastic modulus of the resulting film and to impart heat resistance. The ratio of the total content of propylene homopolymers to the total content of the random copolymers is more preferably 80:20 to 55:45.

[0031] (2) Styrene elastomers The film of the present invention must contain a styrene elastomer in order to reduce cutting debris by lowering the elongation at break of the film without impairing heat resistance or rigidity. While it is also possible to lower the elongation at break of the film by including a predetermined amount of olefin elastomer, in the present invention, by including a styrene elastomer instead of an olefin elastomer in combination with the polyolefin resin, it becomes easier to adjust the elastic modulus of the film, and furthermore, the effect of lowering the elongation at break due to the compatibility of the styrene elastomer with the polyolefin resin can be expected. 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 represented by styrene (hereinafter referred to as the styrene component), and in formula (I), the degree of polymerization may be the same or different at both ends of the molecular chain. Furthermore, Y is at least one selected from butadiene polymer blocks, isoprene polymer blocks, butadiene / isoprene copolymer blocks, hydrogenated butadiene polymer blocks, hydrogenated isoprene polymer blocks, hydrogenated butadiene / isoprene copolymer blocks, partially hydrogenated butadiene polymer blocks, partially hydrogenated isoprene polymer blocks, and partially hydrogenated butadiene / isoprene copolymer blocks. Also, n is an integer of 1 or more.

[0032] Specific examples of styrene-based elastomers include styrene-ethylene-butylene-styrene copolymer, styrene-ethylene-propylene-styrene copolymer, styrene-ethylene-ethylene-propylene-styrene copolymer, styrene-butadiene-butene-styrene copolymer, styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, styrene-hydrogenated butadiene diblock copolymer, styrene-hydrogenated isoprene diblock copolymer, styrene-butadiene diblock copolymer, and styrene-isoprene diblock copolymer. Among these, styrene-ethylene-butylene-styrene copolymer, styrene-ethylene-propylene-styrene copolymer, styrene-ethylene-ethylene-propylene-styrene copolymer, and styrene-butadiene-butene-styrene copolymer are preferred. Block copolymers that are styrene-ethylene-butylene-crystalline olefin copolymers can also be used.

[0033] The melt flow rate of the styrene-based elastomer (measured at a temperature of 230°C and 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. A melt flow rate of 0.1 g / 10 min or more and 10 g / 10 min or less of the styrene-based elastomer is preferable in terms of good compatibility with the aforementioned resin and film-forming properties.

[0034] The styrene content in the styrene-based elastomer is preferably 40% by mass or more. A styrene content of 40% by mass or more is preferable because it does not impair the heat resistance or rigidity of the resulting film, and it reduces the generation of cutting debris when the film is cut with a dicing blade. More preferably, it is 45% by mass or more, and even more preferably 50% by mass or more. The content of styrene components and other components in the styrene-based elastomer is as follows: 1 H-NMR and 13 This can be measured using 1C-NMR. Here, "styrene content" refers to the percentage (mass%) of aromatic vinyl polymer blocks, represented by styrene, based on the mass of the styrene-based elastomer.

[0035] Examples of commercially available styrene-based elastomers with a styrene content of 40% or more include ToughTec H1051, ToughTec H1517, ToughTec H1043, SOE "S1605", SOE "S1606", SOE "S1609", SOE "S1611" (all manufactured by Asahi Kasei), Septon 2104 (all manufactured by Kuraray), and Dynalon 9901P (all manufactured by JSR). In the film of the present invention, one type of styrene-based elastomer may be used alone, or two or more types may be used in combination. The elastomers can be appropriately selected as needed, taking into consideration the film-forming properties when obtaining the film, the effect of reducing cutting debris by adjusting the elongation at break of the obtained film, heat resistance, elastic modulus, and handling properties. Furthermore, in addition to the aforementioned styrene component of 40% by mass or more, it is also possible to add a styrene-based elastomer with a styrene component of 40% by mass or less. The amount of styrene-based elastomer with a styrene component of 40% by mass or less can be appropriately selected so as not to worsen the generation of cutting chips when the resulting film is cut, and without impairing the tensile modulus or tensile elongation at break. When using a combination of materials containing 40% or more styrene by mass and materials containing 40% or less by mass, the ratio of materials containing 40% or more by mass to those containing 40% or less by mass is preferably 90:10 to 60:40. This ratio makes it easy to adjust both the elastic modulus and the elongation at break of the resulting film. More preferably, the ratio of materials containing 40% or more by mass to those containing 40% or less by mass is 85:15 to 65:35.

[0036] (3) Other resins In addition to the polyolefin resins and styrene elastomers mentioned above, other resins can be added to the film of the present invention as long as they do not impair heat resistance or flexibility. Examples of other resins include cyclic olefin resins and polymethylpentene 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 versions of these can also be used.

[0037] As the polymethylpentene resin, it is preferable to use a homopolymer or copolymer with other monomers that uses methylpentene as a monomer. A specific example is a copolymer of α-olefin and 4-methylpentene-1, which was exemplified as another monomer copolymerizable with propylene for polypropylene resins. When the polymethylpentene resin is a copolymer, it is preferable that the content of the α-olefin component used in copolymerization is 20% by mass or less. By limiting it to 20% by mass or less, it is possible to suppress the decrease in the crystal melting peak. More preferably, it is 10% by mass or less. Furthermore, among other resins, those with poor compatibility with polyolefin resins, such as polyethylene terephthalate resins, acrylic resins, urethane resins, and polystyrene resins, should be avoided in combination, as their inclusion can worsen film-forming properties during film formation and increase the likelihood of defects such as unevenness and streaks in the film's appearance.

[0038] (4) Other ingredients Various additives can be incorporated into the film of the present invention to provide properties such as antistatic properties, heat resistance, and weather resistance. For example, antistatic agents, antioxidants, neutralizing agents, lubricants, antiblocking agents, plasticizers, heat stabilizers, light stabilizers, dyes and pigments, nucleating agents, ultraviolet absorbers, fillers, inorganic fillers that impart rigidity, and elastomers other than those mentioned above that impart flexibility may be used, to the extent that they do not hinder the effects of the present invention.

[0039] As polymeric antistatic agents, known ones can be used, for example, a block copolymer of a hydrophobic block and a hydrophilic block can be used. In polymeric antistatic agents, the hydrophobic block and the hydrophilic block form a block copolymer through ester bonds, ether bonds, amide bonds, imide bonds, urethane bonds, and urea bonds, etc.

[0040] Known UV absorbers can be used, such as benzotriazole-based UV absorbers, benzophenone-based UV absorbers, and triazine-based UV absorbers.

[0041] As a light stabilizer, known substances can be used, such as hindered amine-based light stabilizers.

[0042] As a lubricant and antiblocking agent, it is preferable to use a silicone-olefin copolymer because it has excellent compatibility with the aforementioned polypropylene resins, polyethylene resins, etc., and enables the creation of a film that does not suffer from defects due to bleed-out on the surface and provides long-term scratch resistance and slipperiness.

[0043] (5) Film of the present invention The present invention relates to a film composed of a resin composition containing a polyolefin resin and a styrene elastomer, characterized in that the tensile modulus of the film is 450 MPa or more and 800 MPa or less, and the tensile elongation at break is 650% or less.

[0044] The film of the present invention comprises at least one layer made of a resin composition (A) containing a polyolefin resin and a styrene elastomer. It may be a single layer or a multi-layer structure, as long as it can achieve the above-mentioned tensile modulus and tensile elongation at break. A multi-layer film is preferred because it allows for easier adjustment of the film-forming properties and performance of the resulting film.

[0045] There is no limit to the number of layers in a multilayer film, as long as it is composed of multiple layers; however, among these, a 2-type 3-layer or 3-type 3-layer configuration is more preferable because it facilitates the design of the equipment and film manufacturing process, as well as the adjustment of the physical properties of the resulting film. A two-type, three-layer or three-type, three-layer film consists of at least three layers: a surface layer, a back layer, and an intermediate layer. In the case of a two-type, three-layer film, the surface and back layers are made of the same resin or resin composition, while in the case of a three-type, three-layer film, all layers are made of different resins or resin compositions. By creating a film consisting of two types of three layers or three types of three layers, it becomes possible to give each layer—the front and back layers or the intermediate layer—unique characteristics, and it also becomes easy to adjust the film so that only one of the layers—the front and back layers or the intermediate layer—has specific characteristics. In the case of a layer configuration of 2 types and 3 layers, or 3 types and 3 layers or more, the intermediate layer will consist of two or more layers. In that case, the resulting multilayer film will have a film structure consisting of 4 or more layers.

[0046] In one preferred embodiment of the film of the present invention, the film comprises at least three layers, consisting of a surface layer, a backing layer, and an intermediate layer, wherein at least the intermediate layer is made of a resin composition (A).

[0047] Preferably, the thickness of each layer—the surface layer, back layer, and intermediate layer—is within the range of 1-20% of the total thickness of the thermoplastic resin film for the surface layer and back layer, and within the range of 60-98% for the intermediate layer. By setting the thickness of each layer—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 2-18%, the intermediate layer within the range of 64-96%, and even more preferably, the surface layer and back layer are within the range of 4-16%, and the intermediate layer within the range of 68-92%.

[0048] When the film of the present invention is a single-layer film, the content of polyolefin resin and styrene elastomer in the resin composition (A) constituting the film is preferably 60-90% by mass of polyolefin resin, 10-40% by mass of styrene elastomer, and 0-20% by mass of other resins, per 100% by mass of resin composition (A). By using 60-90% by mass of olefin resin, it becomes easy to impart heat resistance and the necessary rigidity to the resulting film, and by using 10-40% by mass of styrene elastomer, it becomes easy to adjust the necessary rigidity and elongation at break. It is more preferable to use 63-93% by mass of polyolefin resin, 7-37% by mass of styrene elastomer, and 0-20% by mass of other resins, and even more preferable to use 65-95% by mass of polyolefin resin, 5-35% by mass of styrene elastomer, and 0-20% by mass of other resins.

[0049] In the case of a multilayer film of the present invention, all layers may be made of resin composition (A), or at least one layer may be a layer that does not contain a styrene-based elastomer. Whether to use a multilayer film with two types and three layers that are the same on both sides, three types and three layers in which all layers are made of different resin compositions, or four or more layers can be appropriately determined according to the required performance of the film. When a multilayer film is used, the resin composition constituting the surface and back layers is preferably a resin composition that essentially contains a polyolefin resin and optionally contains a styrene elastomer (such a resin composition used for the surface and back layers is also referred to as "resin composition (B)"). In the surface and back layers of the multilayer film, the respective content of the polyolefin resin and styrene elastomer in 100% by mass of resin composition (B) is preferably 80-100% by mass of polyolefin resin and 0-20% by mass of styrene elastomer. By having a polyolefin resin content of 80-100% by mass and a styrene elastomer content of 0-20% by mass in the surface and back layers, it becomes easier to adjust the heat resistance and rigidity of the resulting film and maintain a good appearance of the film. The content of polyolefin resin and styrene elastomer in 100% by mass of the resin composition (B) constituting the surface layer and the back layer is more preferably 90-100% by mass of polyolefin resin and 0-10% by mass of styrene elastomer, as this makes it easier to adjust film-forming properties and appearance. It is even more preferable that both the surface layer and the back layer are composed of polyolefin resin and do not contain styrene elastomer or other resins. The resin compositions (B) for the surface and back layers may be two types and three layers using similar compositions, or they may be three types and three layers using different compositions. Whether the surface and back layers are the same or different can be appropriately determined according to the film-forming properties and the physical properties required of the resulting film. The resin composition constituting the intermediate layer is preferably a resin composition (A) containing a polyolefin resin and a styrene elastomer, with the respective content of the polyolefin resin and styrene elastomer in 100% by mass of the resin composition being 50-95% by mass for the polyolefin resin, 5-50% by mass for the styrene elastomer, and 0-20% by mass for the other resin. By including 50-95% by mass of polyolefin resin and 5-50% by mass of styrene elastomer, the heat resistance and rigidity of the resulting film can be easily adjusted. The resin composition (A) constituting the intermediate layer more preferably contains 55 to 90% by mass of polyolefin resin, 10 to 45% by mass of styrene elastomer, and 0 to 20% by mass of other resins in 100% by mass of the resin composition (A), and even more preferably contains 60 to 85% by mass of polyolefin resin and 17 to 40% by mass of styrene elastomer. Furthermore, it is preferable to include styrene elastomer as an essential component in the intermediate layer because it facilitates adjustment of the rigidity and elongation at break of the resulting film. If the intermediate layer is composed of multiple layers, all may be made of the same resin composition, all may be made of different compositions, or some of the layers may be made of different compositions.

[0050] In the case of the film of the present invention described above, whether it is a single-layer film or a multi-layer film, the styrene-based elastomer content refers to the total styrene-based elastomer content. When the film of the present invention described above is a single-layer film, and when the film of the present invention is a multi-layer film, it is preferable to use a styrene-based elastomer that has a styrene component content of 40% by mass or more. Furthermore, when the film of the present invention described above is a single-layer film, or when the film of the present invention is a multi-layer film, and when a styrene component of 40% by mass or more and a styrene component of 40% by mass or less are used in combination, the ratio of the styrene component of 40% by mass or more to the styrene component of 40% by mass or less is preferably 90:10 to 60:40. This ratio makes it easy to adjust both the elastic modulus and the elongation at break of the resulting film. More preferably, the ratio of the styrene component of 40% by mass or more to the styrene component of 40% by mass or less is 85:15 to 65:35.

[0051] The total thickness of the film of the present invention is preferably 30 to 250 μm. A thickness of 30 μm or more allows for good film-forming properties during film production and good handling of the resulting film, while a thickness of 250 μm or less allows for good handling and process passability of the film during the process of laminating a printing layer or adhesive layer onto the film. The thickness of the film of the present invention is more preferably 40 to 210 μm, and even more preferably 50 to 170 μm.

[0052] The tensile modulus of the thermoplastic resin film of the present invention must be within the range of 450 MPa to 800 MPa. Within the range of 450 to 800 MPa, it is easy to suppress problems with handling and process passability due to the film being too flexible or too rigid. More preferably, it is within the range of 480 MPa to 770 MPa, and even more preferably within the range of 510 MPa to 740 MPa.

[0053] Furthermore, the tensile elongation at break of the film of the present invention must be 650% or less. By setting the tensile elongation at break to 650% or less, defects due to breakage can be suppressed even when the film is subjected to adhesive processing, and a reduction in cutting debris when the film is cut with a dicing blade can be expected. More preferably, it is 6300% or less, and even more preferably 610% or less.

[0054] While known methods can be used to form the film of the present invention, it is preferable to use a melt extrusion molding method. Among melt extrusion molding methods, the 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.

[0055] To obtain the film, it is preferable to use a co-extrusion T-die molding method that utilizes multiple extruders. By using a co-extrusion T-die molding method that utilizes multiple extruders, it becomes possible to obtain a multi-layered film. Furthermore, the resin compositions used for the surface layer, back layer, and intermediate layer can all be the same, resulting in a film that is essentially a single layer. A multi-layered film consisting of a surface layer, back layer, and intermediate layer is more preferable because it makes it easier to impart tensile break elongation, tensile modulus, and other functions to the resulting film.

[0056] Co-extrusion T-die molding methods include a method in which a multi-manifold die is used to form multiple resin layers into a film, which are then brought into contact within the T-die to form a multilayer film, and a method in which a device called a feed block is used to combine molten resins, which are then combined and adhered together to obtain a multilayer film. The film may be surface-treated on one or both sides as needed, using methods such as plasma treatment, corona treatment, ozone treatment, and flame treatment. Depending on the intended use of the resulting film, it is possible to choose whether to surface-treat one or both sides.

[0057] 2. Adhesive film The film of the present invention can be made into an adhesive film by providing an adhesive layer on at least one of its front or back surfaces (hereinafter also referred to as "the adhesive film of the present invention"). The adhesive used in the adhesive layer is not particularly limited, but various adhesives such as natural rubber resins, acrylic resins, styrene resins, silicone resins, and polyvinyl ether resins can be used. Furthermore, a functional layer such as an adhesive layer or a thermosetting resin layer may be provided on top of the adhesive layer.

[0058] An adhesive layer can be provided by directly coating the film with adhesive. Alternatively, an adhesive layer can be laminated onto a separator having a release layer, and the adhesive layer side can be bonded to the front or back layer of the film of the present invention, thereby transferring the adhesive layer. In the adhesive film of the present invention, the above-described surface treatment may be performed on one or both sides of the film before the adhesive layer is applied. Furthermore, a primer layer may be provided between the film and the adhesive layer, if necessary.

[0059] The thickness of the adhesive layer and primer layer can be determined as needed. The film of the present invention not only has excellent heat resistance and handling properties, but also reduces cutting debris generated from the film when semiconductor wafers or package-shaped wafers with circuits formed on them are cut into chip-shaped pieces using a dicing blade, thereby suppressing defects caused by cutting debris. Furthermore, an adhesive film can be obtained by laminating an adhesive layer onto the film, and this adhesive film can be suitably used in semiconductor manufacturing processes. [Examples]

[0060] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited in any way by these examples. The materials used in the following examples and comparative examples, the methods for measuring the evaluated properties, etc. are as follows.

[0061] [Materials used] Polypropylene resins, polyethylene resins, olefin elastomers, and styrene elastomers were used as thermoplastic resins as shown below. <Random Polypropylene> Sun Allomer Co., Ltd., "PC630A" (random polypropylene, melt flow rate at 230°C, 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, 2.16 kg: 8.0 g / 10 min, crystal melting peak: 162°C, tensile modulus of single film: 900 MPa) <Styrene-based elastomer> Asahi Kasei Corporation's "SOES1605" (melt flow rate at 230°C, 2.16 kg: 4.7 g / 10 min, styrene component content: 67% by mass, hydrogenated block copolymer composed of blocks of styrene (hard segment) / styrene-butadiene random copolymer (soft segment) / styrene (hard segment)).

[0062] <Preparation of resin composition> The above thermoplastic resins were blended so that each resin composition constituting the surface, intermediate, and back layers totaled 100 parts by mass. When using two or more types, they were mixed by dry blending, and uniform mixing was confirmed visually.

[0063] <Method for forming a film> Each resin composition was loaded into the hopper of three Toshiba Machine single-screw extruders (for the surface layer: 35φmm, L / D=25mm; for the intermediate layer: 50φmm, L / D=32mm; for the back layer: 35φmm, L / D=25mm). The extruder temperature of each extruder was set to 1900-230°C. The three layers (surface, intermediate, and back) were combined in the feed block and extruded through a 650mm wide T-die (temperature setting 190-230°C, lip opening 0.5mm). The thickness configuration was set according to the thicknesses listed in Table 1, and the rotation speed of each extruder was set accordingly. The extruded molten resin was cooled and solidified on a winding machine equipped with a mirror-finish cooling roll (cooling roll 700mm wide x φ350mm, roll temperature approximately 30°C), then corona treatment was performed on both sides and the material was wound up to obtain a multilayer film consisting of two types and three layers with a thickness of approximately 80 μm. In this invention, the mirror-like surface of the obtained film on the cooling roll side is referred to as the surface layer.

[0064] [Thickness of each layer] The thickness of each layer was determined by calculating the amount of resin extruded from each extruder.

[0065] [Total film thickness] The thickness of the film was measured at the center and both ends using a contact-type thickness gauge, and it was confirmed that the film met the specified thickness.

[0066] [Tensile modulus of elasticity] Test specimens were taken from the obtained multilayer film using a dumbbell "SDK-600" manufactured in accordance with JIS K6732. The tensile modulus (MPa) was measured at a tensile speed of 50 mm / min using an Autograph (Shimadzu AGS-X) under the following conditions, referring to JIS K7127: 23°C, 50% RH atmosphere. The tensile modulus was measured in the extrusion direction (MD) of the film.

[0067] [Tensile elongation at breaking] Test specimens were taken from the obtained film using a dumbbell "SDK-600" manufactured in accordance with JIS K6732, and the tensile elongation at break (%) was measured at a tensile speed of 300 mm / min using a small benchtop testing machine (Shimadzu EZ-L) under an atmosphere of 23°C and 50% RH. The tensile elongation at break was measured in the extrusion direction (MD) of the film.

[0068] [Example 1] Random polypropylene and homopolypropylene were used as the thermoplastic resins for the surface and back layers. Random polypropylene, homopolypropylene, and styrene-based elastomer were used as the thermoplastic resins for the intermediate layer. The blending amounts of each resin were as shown in Table 1, and the resin compositions were prepared. Using the above resin compositions, a film consisting of two types and three layers with a total thickness of 150 μm was obtained using the aforementioned film-forming method. The film-forming conditions were adjusted so that the thickness of each layer was 7.5 μm for the surface layer, 135 μm for the intermediate layer, and 7.5 μm for the back layer. This film has a tensile modulus of 550 MPa, which is within the desired range of 450 MPa to 800 MPa. Therefore, it was confirmed that it is not too flexible, has sufficient rigidity, and is easy to handle. Furthermore, the tensile elongation at break was 530%, which is below the desired 650%, suggesting that the generation of cutting chips during machining can be suppressed. Therefore, it was confirmed that this film has appropriate rigidity, is easy to handle, and is presumed to suppress the generation of cutting chips when cut with a dicing blade.

[0069] [Example 2] The procedure was carried out in the same manner as in Example 1, except that the thermoplastic resins for the surface layer, intermediate layer, and back layer were as shown in Table 1. Using the above resin compositions, the film-forming conditions were adjusted using the aforementioned film-forming method to obtain a film consisting of two types and three layers with a total thickness of 150 μm, where the thickness of each layer was 7.5 μm for the surface layer, 135 μm for the intermediate layer, and 7.5 μm for the back layer. This film has a tensile modulus of 520 MPa, which is within the desired range of 450 MPa to 800 MPa. Therefore, it was confirmed that it is not too flexible, has sufficient rigidity, and is easy to handle. Furthermore, the tensile elongation at break was 580%, which is below the desired 650%, suggesting that the generation of cutting chips during machining can be suppressed. Therefore, it was confirmed that this film has appropriate rigidity, is easy to handle, and is presumed to suppress the generation of cutting chips when cut with a dicing blade.

[0070] [Example 3] The procedure was carried out in the same manner as in Example 1, except that the thermoplastic resins for the surface layer, intermediate layer, and back layer were as shown in Table 1. Using the above resin compositions, the film-forming conditions were adjusted using the aforementioned film-forming method to obtain a film consisting of two types and three layers with a total thickness of 150 μm, where the thickness of each layer was 7.5 μm for the surface layer, 135 μm for the intermediate layer, and 7.5 μm for the back layer. This film has a tensile modulus of 520 MPa, which is within the desired range of 450 MPa to 800 MPa. Therefore, it was confirmed that it is not too flexible, has sufficient rigidity, and is easy to handle. Furthermore, since the tensile fracture elongation was 610%, which is below the desired 650%, it can be inferred that the generation of cutting chips during machining can be suppressed. Therefore, it was confirmed that this film has appropriate rigidity, is easy to handle, and is presumed to suppress the generation of cutting chips when cut with a dicing blade.

[0071] [Example 4] The procedure was carried out in the same manner as in Example 1, except that the thermoplastic resins for the surface layer, intermediate layer, and back layer were as shown in Table 1. Using the above resin compositions, the film-forming conditions were adjusted using the aforementioned film-forming method to obtain a film consisting of two types and three layers with a total thickness of 150 μm, where the thickness of each layer was 7.5 μm for the surface layer, 135 μm for the intermediate layer, and 7.5 μm for the back layer. This film has a tensile modulus of 520 MPa, which is within the desired range of 450 MPa to 800 MPa. Therefore, it was confirmed that it is not too flexible, has sufficient rigidity, and is easy to handle. Furthermore, since the tensile fracture elongation was 610%, which is below the desired 650%, it can be inferred that the generation of cutting chips during machining can be suppressed. Therefore, it was confirmed that this film has appropriate rigidity, is easy to handle, and is presumed to suppress the generation of cutting chips when cut with a dicing blade.

[0072] [Comparative Example 1] The procedure was carried out in the same manner as in Example 1, except that the thermoplastic resins for the surface layer, intermediate layer, and back layer were as shown in Table 1. Using the above resin compositions, the film-forming conditions were adjusted using the aforementioned film-forming method to obtain a film consisting of two types and three layers with a total thickness of 150 μm, where the thickness of each layer was 7.5 μm for the surface layer, 135 μm for the intermediate layer, and 7.5 μm for the back layer. This film has a tensile modulus of 680 MPa, which is within the desired range of 450 MPa to 800 MPa. Therefore, it was confirmed that it is not too flexible, has sufficient rigidity, and is easy to handle. However, perhaps due to the low amount of styrene-based elastomer added, this film exhibited a tensile break elongation of 720%, failing to meet the desired 650% or less. Therefore, it is presumed that this film is unlikely to suppress the generation of cutting chips during machining, and is therefore likely to cause problems due to chip generation. Therefore, although this film has moderate rigidity and is easy to handle, it was found that it is a film that is likely to cause problems because it cannot suppress the generation of cutting chips when cut by a dicing blade.

[0073] [Comparative Example 2] The procedure was carried out in the same manner as in Example 1, except that the thermoplastic resins for the surface layer, intermediate layer, and back layer were as shown in Table 1. Using the above resin compositions, the film-forming conditions were adjusted using the aforementioned film-forming method to obtain a film consisting of two types and three layers with a total thickness of 150 μm, where the thickness of each layer was 7.5 μm for the surface layer, 135 μm for the intermediate layer, and 7.5 μm for the back layer. This film has a tensile modulus of 790 MPa, which is within the desired range of 450 MPa to 800 MPa. Therefore, it was confirmed that the film is not too flexible, has sufficient rigidity, and is easy to handle. However, since this film does not contain styrene-based elastomer and its tensile strength at break is 740%, which is below the desired 650%, it is presumed that it cannot suppress the generation of cutting chips when cut, and is a film that is likely to cause problems due to the generation of cutting chips. Therefore, although this film has moderate rigidity and is easy to handle, it was found that it is a film that is likely to cause problems because it cannot suppress the generation of cutting chips when cut by a dicing blade.

[0074] [Table 1]

[0075] [Example 5] An acrylic adhesive (SK Dyne 1502C, manufactured by Soken Chemical Co., Ltd.) was applied to a separator using the comma-coat method so that the thickness of the adhesive layer after drying was 25 μm. After drying in a hot air dryer at 80°C for 5 minutes, the adhesive layer was formed. By laminating the adhesive layer side of the fabricated separator to the surface side of the film obtained in Example 1, an adhesive film was obtained in which the film of the present invention and the adhesive layer were laminated. It is presumed that by using this adhesive film as an adhesive film for semiconductor manufacturing processes, the generation of cutting debris will be suppressed even when the adhesive film is cut with a dicing blade, thereby suppressing defects caused by cutting debris in semiconductor manufacturing processes. [Industrial applicability]

[0076] By using the film of the present invention, in semiconductor manufacturing processes that do not involve an expansion process and require heat resistance and suppression of cutting debris, it is possible to reduce the cutting debris generated from the film cut by a blade when individualizing various materials, not only semiconductor wafers and package-shaped wafers with circuits formed on them, into chip-shaped pieces, and to provide a film with excellent heat resistance and handling properties. Furthermore, by providing an adhesive layer on the film, the present invention can also provide an adhesive film that can be suitably used in semiconductor manufacturing processes.

Claims

1. A substrate film for semiconductor manufacturing processes comprising at least one layer made of a resin composition (A) containing a polyolefin resin and a styrene elastomer, A base film having a tensile modulus of elasticity of 450 MPa or more and 800 MPa or less, and a tensile elongation at break of 650% or less.

2. It consists of at least three layers: a surface layer, a back layer, and an intermediate layer. At least the intermediate layer is a layer made of the resin composition (A), The intermediate layer contains 50 to 95% by mass of a polyolefin resin, 5 to 50% by mass of a styrene elastomer, and 0 to 20% by mass of other resins, based on 100% by mass of the resin composition (A), as described in claim 1, for a substrate film for semiconductor manufacturing processes.

3. The surface layer and the back layer are layers made of a resin composition (B), and each layer contains 80 to 100% by mass of a polyolefin resin and 0 to 20% by mass of a styrene elastomer, according to claim 2.

4. The semiconductor manufacturing process substrate film according to claim 1, wherein the polyolefin resin is a polypropylene resin and / or a polyethylene resin.

5. The semiconductor manufacturing process substrate film according to claim 1, wherein the styrene content of the styrene-based elastomer is 40% by mass or more.

6. The semiconductor manufacturing process substrate film according to claim 4, wherein the polyolefin resin is one or more selected from the group consisting of a propylene homopolymer and a random copolymer of propylene and ethylene or other α-olefins.

7. The resin composition (A) contains, as a polyolefin resin, at least one propylene homopolymer and at least one propylene and ethylene or other α-olefin random copolymer, A substrate film for semiconductor manufacturing processes according to claim 6, wherein the ratio of the total content of propylene homopolymers to the total content of the random copolymers is 80:20 to 50:

50.

8. An adhesive film having an adhesive layer on at least one surface of a substrate film for semiconductor manufacturing processes according to any one of claims 1 to 7.

9. An adhesive film for semiconductor manufacturing processes comprising the adhesive film described in claim 8.

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