Thermoplastic resin film

Abstract

To provide: a thermoplastic resin film that is more sufficiently excellent in all of heat resistance (including melting point properties and heat-resistant dimensional stability), mechanical properties, flexibility, uniformity (including heat resistance uniformity, mechanical uniformity and flexibility uniformity), processing suitability and film-forming properties; and a method for producing the same.SOLUTION: The thermoplastic resin film satisfies the following requirements (1) to (4): (1) a thickness is 60 to 300 μm; (2) a dimensional change rate at 260°C is 10% or smaller in both MD and TD, and a ratio of [dimensional change rate (MD) / dimensional change rate (TD)] is 0.50 to 1.50; (3) a stress at 30% elongation (F30) in a tensile test is 300 N or smaller in both MD and TD, and a ratio of [F30 (MD) / F30 (TD)] is 0.50 to 1.50; and (4) a tensile modulus of elasticity is 1.50 GPa or smaller in both MD and TD, and a ratio of [tensile modulus (MD) / tensile modulus (TD)] is 0.50 to 1.50.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a thermoplastic resin film having excellent heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility and uniformity, a method for producing the same, and a thermoplastic resin film laminate containing the thermoplastic resin film. [Background technology]

[0002] Highly flexible films are used in a wide range of fields, including as base films for adhesive tapes, transfer films for decoration and molding, cushioning films for pressing, and dicing films used in semiconductor manufacturing. In particular, due to the recent supply shortage of semiconductors, more efficient manufacturing methods are being considered, and the use of dicing films for these methods is being actively considered. Furthermore, the performance requirements for dicing films are increasing year by year.

[0003] A dicing film is a film for holding multiple divided semiconductor wafers together in the manufacture of semiconductors. After being attached to a silicon wafer, the dicing film is subjected to a dicing process for dividing the silicon wafer, an expanding process for uniformly expanding the chip intervals by radially stretching the film, and a pick-up process for picking up each divided chip with a needle or the like, and then peeled off. For this reason, the dicing film is required to have dimensional stability, mechanical properties, flexibility, uniformity of the above properties, and processing suitability that does not cause breakage in the expanding process so that the chip intervals can be uniformly expanded (or stretched).

[0004] Reflowed metal is attached to the divided silicon wafers. In recent years, a method has been considered in which silicon wafers are stacked, reflowed metal is attached, and then the silicon wafers are divided. For this reason, dicing films are required to satisfy all the performance requirements for the reflow process, dicing process, expanding process, and pick-up process, and reflow heat resistance is also required.

[0005] As a flexible film, for example, Patent Documents 1 to 3 disclose flexible films made of a polyamide consisting of terephthalic acid, 1,10-decanediamine, dimer acid, and dimer diamine. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2021 / 106541 Brochure [Patent Document 2] International Publication No. 2022 / 054944 Brochure [Patent Document 3] International Publication No. 2023 / 068121 Brochure [Patent Document 4] Patent Publication No. 63-238137 [Patent Document 5] Patent Publication No. 2021-130203 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the film of Patent Document 1 has a problem that it melts when subjected to a reflow process because of insufficient heat resistance (especially melting point characteristics). In addition, the film has a problem of insufficient flexibility because of a high stretching ratio. The film of Patent Document 2 has reflow heat resistance, but has insufficient flexibility because of a high stretching ratio. The film of Patent Document 3 has a thin thickness of 50 μm, so when used as a dicing film, there is a problem that the film breaks during the expanding process. In addition, there is a new problem that the characteristic values ​​of mechanical properties, flexibility, and heat resistance in MD and TD are not uniform.

[0008] In controlling film properties such as heat resistance and flexibility, it is important to control the degree of orientation of the film. Patent Documents 4 and 5 state that the degree of orientation can be controlled by adjusting the draft ratio during film formation. However, any of the properties among heat resistance, mechanical properties, uniformity regarding flexibility, and film formability were still insufficient.

[0009] On the other hand, in dicing films, importance is being placed on resistance to variation in the uniformity of heat-resistant dimensional change rates in both the MD and TD.

[0010] The present invention is intended to solve the above problems, and has an object to provide a thermoplastic resin film that is sufficiently superior in heat resistance (including melting point characteristics and heat-resistant dimensional stability), mechanical properties, flexibility, uniformity (including heat-resistant uniformity, mechanical uniformity, and flexible uniformity), processability, and film-forming properties, and a method for producing the same.

[0011] Another object of the present invention is to provide a thermoplastic resin film that is sufficiently excellent not only in heat resistance (including melting point characteristics and heat-resistant dimensional stability), mechanical properties, flexibility, uniformity (including heat-resistant uniformity, mechanical uniformity and flexibility uniformity), processability and film-forming ability, but also in variation resistance, and a method for producing the same. [Means for solving the problem]

[0012] The inventors of the present invention have discovered that the above problems can be solved by extruding a thermoplastic resin into a film of a specific thickness at a specific draft ratio, adjusting the crystallinity to a specific degree, and then stretching the film at a low ratio, or by restraining the film width and not stretching it to adjust the crystallinity to a specific degree, and have arrived at the present invention.

[0013] The gist of the present invention is as follows. <1> A thermoplastic resin film that satisfies the following requirements (1) to (4). (1) The thickness is 60 to 300 μm; (2) The dimensional change rate at 260°C is 10% or less in both MD and TD, and the [dimensional change rate (MD) / dimensional change rate (TD)] ratio is 0.50 to 1.50; (3) The stress at 30% elongation in the tensile test (F30) is 300 N or less in both MD and TD, and the [F30(MD) / F30(TD)] ratio is 0.50 to 1.50; (4) The tensile modulus of elasticity is 1.50 GPa or less in both MD and TD, and the ratio of [tensile modulus of elasticity (MD) / tensile modulus of elasticity (TD)] is 0.50 to 1.50. <2> The following requirements (1') to (4') are met: <1> The thermoplastic resin film according to claim 1. (1') The thickness is 65 to 250 μm; (2') The dimensional change rate at 260°C is 8% or less in both MD and TD, and the [dimensional change rate (MD) / dimensional change rate (TD)] ratio is 0.65 to 1.30; (3') The stress at 30% elongation in the tensile test (F30) is 200 N or less in both MD and TD, and the [F30(MD) / F30(TD)] ratio is 0.65 to 1.30; (4') The tensile modulus is 1.35 GPa or less in both MD and TD, and the ratio of [tensile modulus (MD) / tensile modulus (TD)] is 0.65 to 1.30. <3> Meet the following requirements (1'') to (4''); <1> The thermoplastic resin film according to claim 1. (1'') thickness is 70-150 μm; (2'') the dimensional change rate at 260°C is 7% or less in both MD and TD, and the [dimensional change rate (MD) / dimensional change rate (TD)] ratio is 0.80 to 1.20; (3'') The stress at 30% elongation in the tensile test (F30) is 150 N or less in both MD and TD, and the [F30(MD) / F30(TD)] ratio is 0.80 to 1.20; (4'') The tensile modulus is 1.20 GPa or less in both MD and TD, and the ratio of [tensile modulus (MD) / tensile modulus (TD)] is 0.80 to 1.20. <4> The variation in the dimensional change rate shown by the following formula is 5% or less. <1> ~ <3> 13. The thermoplastic resin film according to claim 12. X MD Variance = X MD max-X MD min (A) X TD Variance = X TD max-X TD min (B) (X in formula (A) MD max is the maximum dimensional change rate in the MD direction at 260℃, X MD min indicates the minimum value of the dimensional change rate in the MD direction at 260°C, and X in formula (B) TD max is the maximum dimensional change rate in the TD direction at 260℃, X TD min indicates the minimum dimensional change rate in the TD direction at 260°C.) <5> The thermoplastic resin film contains a thermoplastic resin, and the thermoplastic resin has a melting point of 30° C. or more and a melting temperature of 1000 s. -1 The melt viscosity at a shear rate of 30 to 300 mPa s. <1> ~ <4> 13. The thermoplastic resin film according to claim 12. <6> <1> ~ <5> 2. A thermoplastic resin film laminate comprising the thermoplastic resin film according to claim 1. <7> <1> ~ <5> 2. A dicing film using the thermoplastic resin film according to claim 1 . <8> <6> A dicing film using the thermoplastic resin film laminate described in 1. <9> A method for producing a thermoplastic resin film, comprising a film-forming step of melt-mixing a thermoplastic resin and, if necessary, additives, extruding the melt into a sheet through a T-die, bringing the sheet into close contact with a drum, and taking and cooling the sheet to obtain an unstretched film, and further comprising or not including a stretching step of stretching the unstretched film, The exit gap of the T-die during film production (t die ) (μm) and the film thickness at the time of drum withdrawal (t film The draft ratio (t die / t film ) is 1.0 to 20.0, A method for producing a thermoplastic resin film, wherein the stretching ratio is independently 1 to 1.40 times in both MD and TD. <10> The unstretched film has a crystallinity of 65% or more. <9> 2. A method for producing a thermoplastic resin film according to claim 1 . <11> <1> Manufacture the thermoplastic resin film according to <9> or <10> 2. A method for producing a thermoplastic resin film according to claim 1 . <12> The draft ratio (t die / t film ) is 3.0 to 15.0, The stretching ratio is independently 1 to 1.29 times in both MD and TD. <9> 2. A method for producing a thermoplastic resin film according to claim 1 . <13> The unstretched film has a crystallinity of 80% or more. <12> 2. A method for producing a thermoplastic resin film according to claim 1 . <14> <2> Manufacture the thermoplastic resin film according to <12> or <13> 2. A method for producing a thermoplastic resin film according to claim 1 . <15> The draft ratio (t die / t film ) is 8.0 to 15.0, The stretching ratio is independently 1 to 1.08 times in both MD and TD. <9> 2. A method for producing a thermoplastic resin film according to claim 1 . <16> The unstretched film has a crystallinity of 83% or more. <15> 2. A method for producing a thermoplastic resin film according to claim 1 . <17> <3> Manufacture the thermoplastic resin film according to <15> or <16> 2. A method for producing a thermoplastic resin film according to claim 1 . Effect of the Invention

[0014] According to the present invention, it is possible to provide a thermoplastic resin film which is sufficiently superior in both processability and film-formability, including mechanical properties, flexibility, uniformity, heat-resistant uniformity, mechanical uniformity, and flexible uniformity, including heat-resistant melting point characteristics and heat-resistant dimensional stability. The thermoplastic resin film of the present invention can be suitably used as a dicing film or the like. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The thermoplastic resin contained in the thermoplastic resin film of the present invention is not particularly limited, and examples thereof include polyamide, polyester, polyolefin, polyether ether ketone, and polyether ketone ketone. From the viewpoints of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, as well as improving resistance to variation, the thermoplastic resin preferably contains one or more thermoplastic resins selected from the group consisting of polyamide and polyester, and more preferably contains polyamide.

[0016] In this specification, heat resistance includes melting point characteristics and heat-resistant dimensional stability, and therefore excellent heat resistance means excellent in both melting point characteristics and heat-resistant dimensional stability. The melting point characteristic is the characteristic of a higher melting point. The higher the melting point, the better the melting point characteristic. Heat resistant dimensional stability refers to the property of having smaller dimensional change rates in both MD and TD when measured at 260°C using a thermomechanical analyzer. Note that MD refers to the longitudinal direction (or machine direction) of the film, and TD refers to the direction perpendicular to MD.

[0017] The mechanical properties are defined as properties that have a smaller tensile stress in both MD and TD at 30% elongation stress measured using a tensile tester. The flexibility refers to a property having a smaller tensile modulus of elasticity in both MD and TD when measured using a tensile tester.

[0018] The uniformity includes heat resistance uniformity, mechanical uniformity, and flexibility uniformity. Therefore, excellent uniformity means excellent in all of the properties of heat resistance uniformity, mechanical uniformity, and flexibility uniformity. Heat resistance uniformity refers to the uniformity of heat resistance dimensional change rate in both MD and TD (plane direction), and is a characteristic expressed as the ratio of the average heat resistance dimensional change rate in MD to the average heat resistance dimensional change rate in TD, and indicates the MD / TD balance of the dimensional change rate at the measurement point. The closer the ratio is to 1, the better the heat resistance uniformity is. Mechanical uniformity refers to the uniformity of stress at 30% elongation in both MD and TD (plane directions), and is a property expressed as the ratio of the average stress at 30% elongation in MD to the average stress at 30% elongation in TD. The closer this ratio is to 1, the better the mechanical uniformity is. Flexibility uniformity refers to the uniformity of the tensile modulus in both MD and TD (plane direction), and is a property expressed as the ratio of the average tensile modulus in MD to the average tensile modulus in TD. The closer the ratio is to 1, the better the flexibility uniformity is.

[0019] The processability refers to a property that makes it difficult to break even when expanded, for example, a property that causes fewer breaks during an expanding process. The film-forming property is a property that reduces thickness unevenness and is expressed as the ratio of the difference between the maximum thickness and the minimum thickness to the average thickness. The smaller the ratio, the better the film-forming property.

[0020] The variation resistance refers to the uniformity of the heat-resistant dimensional change rate in each of MD and TD, and is a property represented by the difference between the maximum heat-resistant dimensional change rate and the minimum heat-resistant dimensional change rate in each of MD and TD, and indicates the degree of variation in the dimensional change rate throughout the film. In both MD and TD, the smaller the difference, the better the variation resistance. Note that the variation resistance is not necessarily a property that the thermoplastic resin film of the present invention must have, but is a property that it is preferable to have.

[0021] The polyamide is not particularly limited, and examples thereof include copolymer polyamide, polyamide 11, and polyamide 12, among which copolymer polyamide is preferable. Examples of the copolymer polyamide include polyamides including units consisting of an aliphatic dicarboxylic acid (A) having 18 or more carbon atoms (hereinafter sometimes referred to as component (A)), units consisting of an aliphatic diamine (B) having 18 or more carbon atoms (hereinafter sometimes referred to as component (B)), units consisting of an aromatic dicarboxylic acid (C) having 12 or less carbon atoms (hereinafter sometimes referred to as component (C)), and units consisting of an aliphatic diamine (D) having 12 or less carbon atoms (hereinafter sometimes referred to as component (D)); and polyether block amide copolymers described later.

[0022] Components (A) to (D) are contained in the polyamide as monomer components (or monomer residues). In this specification, "units consisting of an aliphatic dicarboxylic acid (A) having 18 or more carbon atoms" may be abbreviated simply as "residue of component (A)", "units consisting of an aliphatic diamine (B) having 18 or more carbon atoms" may be abbreviated simply as "residue of component (B)", "units consisting of an aromatic dicarboxylic acid (C) having 12 or less carbon atoms" may be abbreviated simply as "residue of component (C)", and "units consisting of an aliphatic diamine (D) having 12 or less carbon atoms" may be abbreviated simply as "residue of component (D)".

[0023] The aliphatic dicarboxylic acid (A) having 18 or more carbon atoms constituting the polyamide is preferably an aliphatic dicarboxylic acid consisting entirely of hydrocarbons except for the carboxyl group, such as hexadecanedicarboxylic acid (18 carbon atoms), octadecanedicarboxylic acid (20 carbon atoms), dimer acid (C36) (36 carbon atoms), and dimer acid (C44) (44 carbon atoms). Among them, an aliphatic dicarboxylic acid having 20 or more carbon atoms is preferred because it has high flexibility, and dimer acid (C36) and dimer acid (C44) are more preferred. The dimer acid may be a product of an addition reaction between two molecules selected from unsaturated fatty acids such as oleic acid and linoleic acid. The two molecules may be the same type of molecule or different types of molecules. The dimer acid may be a dicarboxylic acid having an unsaturated bond, but is preferably a dicarboxylic acid in which all bonds are saturated bonds by hydrogenation because it is less likely to be discolored. The component (A) may be one of the above alone, or two or more may be used in combination.

[0024] From the viewpoints of further improving heat resistance (including heat resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-formability, as well as improving resistance to variation, the number of carbon atoms in component (A) is preferably 20 to 50, more preferably 30 to 48, even more preferably 30 to 44, sufficiently preferably 30 to 40, and even more preferably 34 to 38.

[0025] The content of component (A) is not particularly limited, and may be, for example, 0 to 45% by mass. From the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, as well as improving resistance to variation, it is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, even more preferably 0 to 25% by mass, particularly preferably 3 to 25% by mass, sufficiently preferably 5 to 25% by mass, more sufficiently preferably 10 to 20% by mass, and most preferably 15 to 20% by mass. The content is the content of the residue of component (A) and is the ratio to the total monomer components (or the total amount of their residues) constituting the polyamide. When the polyamide contains two or more kinds of components (A), the total amount of them may be within the above range. The content of 0% by mass means that the polyamide does not contain the component (A).

[0026] The aliphatic diamine (B) having 18 or more carbon atoms constituting the polyamide is preferably an aliphatic dicarboxylic acid consisting entirely of hydrocarbons except for amino groups, such as octadecanediamine (18 carbon atoms), eicosanediamine (20 carbon atoms), and dimer diamine (36 carbon atoms). Among them, dimer diamine is preferred because it has high flexibility. Dimer diamine is usually produced by reacting dimer acid with ammonia, followed by dehydration, nitrification, and reduction. Dimer diamine may be a diamine having an unsaturated bond, but is preferably a diamine in which all bonds are saturated by hydrogenation, because it is less likely to be discolored. As component (B), one of the above may be used alone, or two or more may be used in combination.

[0027] From the viewpoints of further improving heat resistance (including heat resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-formability, as well as improving resistance to variation, the carbon number of component (B) is preferably 20 to 40, more preferably 30 to 40, and even more preferably 34 to 38.

[0028] The content of component (B) is not particularly limited, and may be, for example, 0 to 45% by mass. From the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, as well as improving resistance to variation, it is preferably 0 to 40% by mass, more preferably 0 to 30% by mass, even more preferably 0 to 25% by mass, particularly preferably 3 to 25% by mass, sufficiently preferably 5 to 25% by mass, more sufficiently preferably 10 to 20% by mass, and most preferably 15 to 20% by mass. The content is the content of the residue of component (B) and is the ratio to the total monomer components (or the total amount of their residues) constituting the polyamide. When the polyamide contains two or more kinds of components (B), the total amount of them may be within the above range. The content of 0% by mass means that the polyamide does not contain the component (B).

[0029] Examples of aromatic dicarboxylic acids (C) having 12 or less carbon atoms constituting the polyamide include terephthalic acid (8 carbon atoms), isophthalic acid (8 carbon atoms), and orthophthalic acid (8 carbon atoms). Among them, from the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming property, as well as improving resistance to variation, aromatic dicarboxylic acids having 8 or more carbon atoms are preferred, and terephthalic acid is more preferred. As component (C), one of the above may be used alone, or two or more may be used in combination.

[0030] From the viewpoints of further improving heat resistance (including heat resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-formability, as well as improving resistance to variation, the carbon number of component (C) is preferably 4 to 12, more preferably 6 to 12, and even more preferably 6 to 10.

[0031] The content of component (C) is not particularly limited, and may be, for example, 3 to 50% by mass. From the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, as well as improving resistance to variation, it is preferably 5 to 50% by mass, more preferably 8 to 50% by mass, even more preferably 15 to 45% by mass, particularly preferably 20 to 40% by mass, sufficiently preferably 25 to 40% by mass, more sufficiently preferably 27 to 40% by mass, and most preferably 27 to 35% by mass. The content is the content of the residue of component (C) and is the ratio to the total amount of all monomer components (or the total amount of their residues) constituting the polyamide. When the polyamide contains two or more kinds of components (C), the total amount of them may be within the above range.

[0032] Examples of the aliphatic diamine (D) having 12 or less carbon atoms constituting the polyamide include 1,12-dodecanediamine (12 carbon atoms), 1,10-decanediamine (10 carbon atoms), 1,9-nonanediamine (9 carbon atoms), 1,8-octanediamine (8 carbon atoms), 2-methyl-1,8-octanediamine (9 carbon atoms), and 1,6-hexanediamine (6 carbon atoms). Among them, from the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming property, as well as improving resistance to variation, diamines having 6 or more carbon atoms are preferred, diamines having 8 or more carbon atoms are more preferred, and 1,10-decanediamine is even more preferred. As the component (D), one of the above may be used alone, or two or more may be used in combination.

[0033] From the viewpoints of further improving heat resistance (including heat resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-formability, as well as improving resistance to variation, the carbon number of component (D) is preferably 4 to 12, more preferably 6 to 12, and even more preferably 8 to 12.

[0034] The content of component (D) is not particularly limited, and may be, for example, 3 to 60% by mass. From the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming property, as well as improving resistance to variation, it is preferably 3 to 52% by mass, more preferably 5 to 50% by mass, even more preferably 10 to 50% by mass, particularly preferably 15 to 50% by mass, sufficiently preferably 20 to 50% by mass, more sufficiently preferably 30 to 40% by mass, and most preferably 34 to 38% by mass. The content is the content of the residue of component (D) and is the ratio to the total monomer components (or the total amount of their residues) constituting the polyamide. When the polyamide contains two or more kinds of components (D), the total amount of them may be within the above range.

[0035] As the combination of (A) to (D), the following combinations are preferable: (1) Dimer acid; Dimer diamine; Terephthalic acid; 1,10-decanediamine; (2) Dimer acid; dimer diamine; terephthalic acid; 1,9-nonanediamine and 2-methyl-1,8-octanediamine; (3) Dimer acid; dimer diamine; terephthalic acid; 1,10-decanediamine, 1,9-nonanediamine and 2-methyl-1,8-octanediamine; (4) Terephthalic acid; 1,9-nonanediamine and 2-methyl-1,8-octanediamine.

[0036] The polyamide may be a random type polyamide in which the components (A) to (D) are randomly arranged and polymerized, or may be a block type polyamide containing a hard segment consisting of the components (C) and (D) and a soft segment consisting of the components (A) and (B). From the viewpoint of further improving heat resistance (including heat resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, as well as improving resistance to variation, the polyamide preferably contains, for example, a combination of terephthalic acid and one or more aliphatic diamines selected from the group consisting of butanediamine, 1,9-nonanediamine, 1,10-decanediamine, 2-methyl-1,8-octanediamine, and 1,12-dodecanediamine as a combination of the components (C) and (D). From the same viewpoint as above, the polyamide more preferably contains a combination of terephthalic acid and one or more aliphatic diamines selected from the group consisting of 1,9-nonanediamine and 1,10-decanediamine. When polyamide contains such a combination, these components tend to become highly crystalline segments as hard segments, which promotes the formation of a phase separation structure between hard and soft segments, resulting in more adequate flexibility (especially rubber elasticity). The word "rubber" is used to refer to a material that exhibits the property of being locally deformed by an external force but returning to its original shape when the force is removed.

[0037] The total content of the units consisting of the aliphatic dicarboxylic acid (A) having 18 or more carbon atoms and the units consisting of the aliphatic diamine (B) having 18 or more carbon atoms in the polyamide used in the present invention is preferably 10 to 90% by mass, more preferably 15 to 80% by mass, even more preferably 15 to 65% by mass, particularly preferably 15 to 50% by mass, sufficiently preferably 20 to 50% by mass, more sufficiently preferably 30 to 40% by mass, and most preferably 30 to 38% by mass, from the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, and improving resistance to variation. The total content is the total content of the residues of component (A) and the residues of component (B), and is the ratio to all monomer components constituting the polyamide (or the total amount of their residues). When the thermoplastic resin contains an impact-resistant agent described later, it is preferable that the total content of the units consisting of the aliphatic dicarboxylic acid (A), the units consisting of the aliphatic diamine (B), and the impact-resistant agent is within the above range. Specifically, it is preferable that the total content of components (A) and (B) relative to all monomer components constituting the polyamide (or the total amount of their residues), and the content and total content of the impact-resistant agent relative to 100 mass% of the polyamide, are within the above-mentioned ranges.

[0038] The polyamide may contain a terminal blocking agent for adjusting the degree of polymerization, inhibiting decomposition or coloring of the product, etc. Examples of the terminal blocking agent include monocarboxylic acids such as acetic acid, lauric acid, benzoic acid, and stearic acid, and monoamines such as octylamine, cyclohexylamine, aniline, and stearylamine. The terminal blocking agent may be used alone or in combination of two or more of the above. The content of the terminal blocking agent is not particularly limited, but is usually 0 to 10 mol% based on the total molar amount of the dicarboxylic acid and the diamine.

[0039] The method for producing polyamide is not particularly limited, and for example, it can be obtained by a method of reacting an aliphatic dicarboxylic acid (A) having 18 or more carbon atoms, an aliphatic diamine (B) having 18 or more carbon atoms, an aromatic dicarboxylic acid (C) having 12 or less carbon atoms, and an aliphatic diamine (D) having 12 or less carbon atoms all at once (hereinafter, sometimes referred to as a "bulk polymerization method"), or a method of reacting components (C) and (D) separately from components (A) and (B) (hereinafter, sometimes referred to as a "split polymerization method"). In the split polymerization method, for example, components (C) and (D) are reacted in advance. Then, after components (A) and (B) are reacted, a reaction product of components (C) and (D) may be added and further reacted.

[0040] When producing the polyamide, a catalyst may be used as necessary. Examples of the catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid, and salts thereof. The content of the catalyst is not particularly limited, but is usually 0 to 2 mol% based on the total molar amount of the dicarboxylic acid and the diamine.

[0041] During the production of the polyamide, an organic solvent or water may be added, if necessary.

[0042] The polymerization of polyamide may be carried out in a closed system or at normal pressure. When the polymerization is carried out in a closed system, the pressure may increase due to the evaporation of the monomer or the generation of condensed water, so it is preferable to control the pressure appropriately. On the other hand, if the boiling point of the monomer used is high and the monomer does not flow out of the system even without pressurization, the polymerization can be carried out at normal pressure. For example, in the case of a combination of dimer acid, dimer diamine, terephthalic acid, and decane diamine, the polymerization can be carried out at normal pressure.

[0043] During the production of polyamide, it is preferable to carry out the polymerization in a nitrogen atmosphere or under vacuum in order to prevent oxidative deterioration.

[0044] The polymerized polyamide may be extruded in the form of strands and formed into pellets, or may be hot-cut or underwater-cut into pellets.

[0045] After polymerization, the polyamide may be subjected to solid-phase polymerization in order to further increase the molecular weight. Solid-phase polymerization is particularly effective when the viscosity during polymerization is high and operation becomes difficult. Solid-phase polymerization is preferably performed by heating at a temperature below the melting point of the resin composition under an inert gas flow or reduced pressure for 30 minutes or more, more preferably for 1 hour or more.

[0046] The polyamide may include two or more polyamides having different monomer compositions (types), monomer sequences, and / or molecular weights (particularly melting points). The two or more polyamides may be two or more polyamides selected from the above-mentioned range of polyamides. Thus, each of the two or more polyamides may include components (A) to (D).

[0047] Examples of polyamide 11 include Rilsan BECNO TL, BESN MED, BESNO TL, and BMNO manufactured by Arkema.

[0048] Examples of polyamide 12 include Rilsamid, AESNO P40 TL, AESNO P302 TL, AESNO 14 TL, and AESNO MED manufactured by Arkema.

[0049] The molecular weight of the polyamide may be such that the polyamide has the melting point of the thermoplastic resin described below.

[0050] The polyether block amide copolymer is a polymer formed by alternating polymerization of polyamide segments having carboxyl groups at both ends and polyether segments having hydroxyl groups at both ends via ester bonds.

[0051] The polyamide portion constituting the polyether block amide copolymer functions as a hard segment. The polyamide portion as such a hard segment is a polymer portion formed by alternately polymerizing dicarboxylic acid and diamine via amide bonds. The degree of polymerization of the polyamide portion is not particularly limited.

[0052] The polyether portion constituting the polyether block amide copolymer functions as a soft segment. The polyether portion as such a soft segment is a polymer portion formed by alternating polymerization of diols via ether bonds. The degree of polymerization of the polyether portion is not particularly limited.

[0053] The molecular weight of the polyether block amide copolymer may be any molecular weight so long as the polyether block amide copolymer has the melting point of the thermoplastic resin described below.

[0054] Polyether block amide copolymers are available, for example, as Pebax, 7233, 7033, 6333, 5533, 4033, MX1205, 3533, and 2533 manufactured by Arkema.

[0055] For example, when the thermoplastic resin film of the present invention contains polyamide, the thermoplastic resin film may contain polyester as a thermoplastic resin in addition to polyamide. The polyester is not particularly limited and may be any polyester. The polyester is preferably a copolymer polyester from the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming property, as well as improving resistance to variation.

[0056] A copolymer polyester is a polymer formed by alternating polymerization of a polyester portion having a carboxyl group at one end and a hydroxyl group at the other end and a polyether portion having a carboxyl group at one end and a hydroxyl group at the other end via ester bonds.

[0057] The polyester portion constituting the copolymer polyester functions as a hard segment. The polyester portion as such a hard segment is a polymer portion formed by alternating polymerization of a dicarboxylic acid and a diol via an ester bond. Examples of the dicarboxylic acid include terephthalic acid and isophthalic acid. Examples of the diol include tetraethylene glycol.

[0058] The polyether portion constituting the copolymer polyester functions as a soft segment. The polyether portion as such a soft segment is a polymer portion formed by alternating polymerization of dicarboxylic acid and polyoxyalkylene glycol via ester bonds. Examples of dicarboxylic acid include terephthalic acid and isophthalic acid. Examples of polyoxyalkylene glycol include polyethylene glycol and polypropylene glycol. The degree of polymerization of the polyoxyalkylene glycol is not particularly limited. The degree of polymerization of the polyether portion is not particularly limited.

[0059] A specific example of a preferred copolymer polyester is a copolymer of polybutylene terephthalate and polyether, which is available as, for example, Hytrel 2751, 2571, 7247, 7277, 6347, 5557, 4767N, 4047N, 3548L, 3046, SB754, SB704, or SB654 manufactured by Toray Industries, Inc.

[0060] The molecular weight of the polyester may be such that the polyester has the melting point of the thermoplastic resin described below.

[0061] The polyester may be added at any stage during the production of the film. For example, the polyester may be added during or before melt mixing of the thermoplastic resin during the production of the unstretched film. For example, the polyester may be in the form of pellets that have been melt mixed with the thermoplastic resin before the production of the unstretched film.

[0062] For example, when the thermoplastic resin film of the present invention contains polyamide, the thermoplastic resin film may further contain other polymers, particularly other thermoplastic polymers, as needed, in addition to polyamide, within a range that does not impair the effects of the present invention as a thermoplastic resin. Examples of other polymers, particularly other thermoplastic polymers, include impact resistance agents such as polyolefin-based elastomers, polyester-based elastomers, polyamide-based elastomers, and polystyrene-based elastomers. The content of other polymers is preferably 50% by mass or less, more preferably 30% by mass or less, even more preferably 25% by mass or less, particularly preferably 10% by mass or less, sufficiently preferably 5% by mass or less, and most preferably 0% by mass, based on 100% by mass of polyamide.

[0063] Specific examples of polyolefin-based elastomers include Tafmer MH7020 (manufactured by Mitsui Chemicals, Inc., maleic anhydride modified polyolefin), Tafmer MH8510 (manufactured by Mitsui Chemicals, Inc., maleic anhydride modified polyolefin), Tafmac M1913 (manufactured by Asahi Kasei Corporation, maleic anhydride modified polystyrene-hydrogenated polybutadiene copolymer), Tafmer A1050S (manufactured by Mitsui Chemicals, Inc., acid unmodified polyolefin), EVOLUE-SP0540 (manufactured by Polyplastics Co., Ltd., ethylene / hexene copolymer), EVOLUE-SP0510 (manufactured by Polyplastics Co., Ltd., Examples of the copolymers include Apolhya-LP21H (manufactured by Arkema Corporation, ethylene / ethyl acrylate / maleic anhydride / polyamide 6), Apolhya-LP1 (manufactured by Arkema Corporation, ethylene / butyl acrylate / maleic anhydride / polyamide 6), Apolhya-LP3 (manufactured by Arkema Corporation, ethylene / ethyl acrylate / maleic anhydride / polyamide 6), and Apolhya-LP91 (manufactured by Arkema Corporation, ethylene / butyl acrylate / maleic anhydride / polyamide 6).

[0064] Specific examples of polyester elastomers include PRIT30 (manufactured by Bell Polyester Products Co., Ltd.) and OKY (manufactured by Bell Polyester Products Co., Ltd.).

[0065] Specific examples of polyamide-based elastomers include TPAE-8 (manufactured by T&K Toka Corporation) and TPAE-H151TPAE-8 (manufactured by T&K Toka Corporation). Specific examples of polystyrene elastomers include TEFABLOCK. TM TPS SJ4300C (Mitsubishi Chemical), Tefablock TM Examples include TPS ME5309C (manufactured by Mitsubishi Chemical Corporation).

[0066] From the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming properties, as well as improving resistance to variation, the impact-resistant agent is preferably a polymer selected from the group consisting of polyolefin-based elastomers and polyester-based elastomers. From the same viewpoint, more preferred impact-resistant agents are polymers selected from the group consisting of maleic anhydride-modified polyolefins, ethylene / hexene copolymers, ethylene glycol / butanediol / terephthalic acid / 36 dimer acid copolymers, and ethylene glycol / cyclohexanedimethanol / cyclohexanedicarboxylic acid / 44 dimer acid copolymers, and even more preferred impact-resistant agents are polymers selected from the group consisting of maleic anhydride-modified polyolefins, ethylene glycol / butanediol / terephthalic acid / 36 dimer acid copolymers, and ethylene glycol / cyclohexanedimethanol / cyclohexanedicarboxylic acid / 44 dimer acid copolymers. The 36 dimer acid and 44 dimer acid refer to dimer acids having 36 and 44 carbon atoms, respectively.

[0067] The molecular weight of the impact-resistant agent may be such that the thermoplastic resin containing the impact-resistant agent has a melting point as described below. The impact-resistant agent may be in the same range as the melting point of the thermoplastic resin as described below.

[0068] These impact-resistant agents may be added at any stage during the production of the film. For example, the impact-resistant agent may be added during or before the melt mixing of the thermoplastic resin during the production of the unstretched film. Also, for example, the impact-resistant agent may be in the form of pellets that have been melt mixed with the thermoplastic resin before the production of the unstretched film.

[0069] The melting point of the thermoplastic resin is usually 270°C or higher, and from the viewpoint of heat resistance, it is preferably 280°C or higher, more preferably 290°C or higher, and even more preferably 300°C or higher. If the melting point is too low, the heat resistance is poor, and it cannot withstand use as, for example, a dicing film. For example, when the thermoplastic resin contains an impact resistance agent, the melting point of the thermoplastic resin containing the impact resistance agent may be within the above range.

[0070] The melting point of the thermoplastic resin is determined using a differential scanning calorimeter and is determined based on the temperature at the top of the endothermic peak when the temperature is increased at a rate of 20° C. / min.

[0071] The thermoplastic resin film of the present invention can be produced by a method including a film-forming step in which a thermoplastic resin and, if necessary, additives described below are melt-mixed, the molten material is extruded into a sheet through a T-die, and the sheet is brought into close contact with a drum (e.g., a casting roll (CR)), and then the sheet is taken up and cooled at a predetermined speed to obtain an unstretched film.

[0072] In the film-making process, the exit gap of the T-die during film-making (t die ) (μm) and the film thickness at the time of drum withdrawal (t film The draft ratio (t die / t film) must be 1.0 to 20.0, and from the viewpoint of further improving heat resistance (including heat resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, as well as improving resistance to variation, it is more preferable to set it to 3.0 to 15.0, and even more preferable to set it to 8.0 to 15.0. If the draft ratio exceeds 20.0, the dimensional change rates in MD and TD, the stress at 30% elongation, and the tensile modulus of elasticity become non-uniform, which is not preferable. On the other hand, if the draft ratio is less than 1.0, the dimensional change rate becomes large or becomes non-uniform, which is not preferable. If the draft ratio is less than 1.0, t die When is too small and t film may be too large. For example, t die If the diameter is too small, such as less than 300 μm, the heat resistant dimensional stability and heat resistant uniformity are reduced, and a deposit called "eye plaster" is likely to occur on the T-die lip surface during film formation, making long-term production difficult. film If the thickness is too large, such as exceeding 300 μm, the degree of adhesion to the cooling drum decreases, making it difficult to control the crystallinity uniformly, reducing the resistance to variation and making it impossible for the film to be expanded in the expanding step, which is not preferable.

[0073] T die exit gap (t die ) (μm) refers to the dimension in the thickness direction at the exit of the T-die, and can be controlled by selecting the T-die to be used.

[0074] Film thickness at drum withdrawal (t film ) (μm) refers to the thickness when the film (especially the sheet-like melt) first comes into contact with the drum, and refers to the state before the film starts to be taken up by the drum. film ) can be controlled by adjusting the distance Ld from the die exit to the drum. For example, by making the distance Ld longer, the film thickness (t film ) becomes smaller. For example, if the distance Ld is made shorter, the film thickness (t filmGenerally, Ltd is preferably 10 to 300 mm, more preferably 10 to 250 mm, and most preferably 10 to 200 mm.

[0075] Specifically, when polyamide is used as the thermoplastic resin, the polyamide is melt-mixed at 240 to 340°C for 3 to 15 minutes, extruded into a sheet through a T-die, brought into close contact with a drum (e.g., CR), and cooled to obtain an unstretched film. die / t film The temperature (particularly the surface temperature) of the drum (CR) is preferably from -10 to 80°C, more preferably from 10 to 80°C, and most preferably from 30 to 80°C, from the viewpoint of adjusting the crystallinity.

[0076] The melt viscosity of the thermoplastic resin is set to a temperature of melting point +30°C and 1000s from the viewpoints of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming properties, as well as improving resistance to variation. -1 Under the shear rate condition, the melt viscosity is preferably 30 to 300 mPa·s, more preferably 40 to 250 mPa·s, even more preferably 50 to 200 mPa·s, even more preferably 100 to 200 mPa·s, and even more preferably 120 to 200 mPa·s. When the melt viscosity is low, even if the draft ratio is 20 or less, a poor appearance called draw resonance may occur during film formation, heat resistance may decrease, or thickness unevenness may increase, resulting in decreased film formability. In addition, when the melt viscosity is high, the filter pressure rise may become significant, resulting in decreased production efficiency. For example, when the thermoplastic resin contains an impact resistance agent, the melt viscosity of the thermoplastic resin containing the impact resistance agent may be within the above range.

[0077] The melt viscosity of thermoplastic resin is measured based on JIS K 7210-1 under the conditions of melting point +30℃ and preheating for 3 minutes. The melting point is the melting point of the thermoplastic resin.

[0078] The method for quenching the thermoplastic resin extruded from the T-die is not particularly limited, but it is preferable to quench the molten resin as quickly as possible. Examples of the quenching method include known methods such as the air knife method, the electrostatic adhesion method, and the vacuum chamber method.

[0079] The thermoplastic resin film of the present invention may be stretched at a relatively low ratio or may not be stretched. For example, when the thermoplastic resin film of the present invention is a dicing film, the dicing film is preferably stretched and oriented because heat resistance is required, but excessive stretching and orientation is not preferred because flexibility is also required. Therefore, the thermoplastic resin film of the present invention needs to be a film stretched at a relatively low ratio or an unstretched film. The stretching ratios in both MD and TD must be independently 1.40 times or less (particularly 1 to 1.40 times), and from the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming property, and improving resistance to variation, it is preferably 1.29 times or less (particularly 1 to 1.29 times), more preferably 1.08 times or less (particularly 1 to 1.08 times). If the stretching ratio is too large, the flexibility decreases. The detailed stretching method will be described below. Note that a stretching ratio of 1 time means that no stretching treatment is performed.

[0080] A dicing film is a film used to hold together multiple divided semiconductor wafers at least during the dicing process in the semiconductor manufacturing process, and is also called a "film for dicing tape" or "dicing tape."

[0081] Stretching at a relatively low magnification ratio occurs in or near the elastic deformation region, so if a typical stretching method is used, in which stretching is performed from a nearly amorphous state and then crystallization is performed by heat setting, the stretching will be non-uniform. Such a typical stretching method is likely to result in large variations in physical properties, especially in the TD direction. If the physical properties in the TD direction, especially the dimensional change rate at 260°C, vary greatly, peeling is likely to occur between the dicing film and the silicon wafer, or between the dicing film and the ring frame, during the reflow process. Furthermore, distortion is likely to cause problems in the subsequent dicing process. In the expanding process Expansion In order to make the crystallinity uniform, it is preferable to increase the crystallinity of the unstretched film.

[0082] As a method for increasing the crystallinity of the unstretched film, a method for adjusting the temperature of the drum (e.g., CR) after discharge from the T-die, or a method for performing heat setting treatment before stretching with a stretching machine can be mentioned. In order to uniformize the stretching at a low ratio, the crystallinity of the unstretched film, calculated by the method described below, is preferably adjusted to 65% or more, more preferably adjusted to 80% or more, even more preferably adjusted to 83% or more, sufficiently preferably adjusted to 85% or more, and most preferably adjusted to 90% or more. For example, if the drum temperature is increased, the crystallinity of the unstretched film increases. Also, for example, if the drum temperature is decreased, the crystallinity of the unstretched film decreases. Regarding the method for performing heat setting treatment, if the heat setting temperature is increased, the crystallinity of the unstretched film increases, and if the heat setting temperature is decreased, the crystallinity of the unstretched film decreases.

[0083] When stretched at a relatively low ratio, the thermoplastic resin film of the present invention may be stretched either uniaxially or biaxially. In the present invention, the stretching is preferably biaxially stretched from the viewpoints of further improving heat resistance (including heat resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film formability, as well as improving resistance to variation.

[0084] Specific methods for stretching a film include, for example, a sequential biaxial stretching method (for example, a flat-type sequential biaxial stretching method), a simultaneous biaxial stretching method (for example, a flat-type simultaneous biaxial stretching method), and a tubular method. Among them, it is preferable to adopt a simultaneous biaxial stretching method (for example, a flat-type simultaneous biaxial stretching method) from the viewpoint of improving the thickness accuracy of the film and making the MD physical properties of the film uniform. Examples of stretching devices include a screw-type tenter, a pantograph-type tenter, and a linear motor-driven clip-type tenter.

[0085] The simultaneous biaxial stretching method is not particularly limited, but may be, for example, a method in which a first heat setting process (hereinafter, sometimes referred to as "heat setting process MT1") is performed, followed by simultaneous biaxial stretching of an unstretched film, and then a second heat setting process (hereinafter, sometimes referred to as "heat setting process MT2"). Stretching is performed at "film melting point -200°C" to "film melting point -30°C" at 1.00 to 1.40 times the original length in both TD and MD. From the viewpoint of further improving heat resistance (including heat-resistant dimensional stability), mechanical properties, flexibility, uniformity, processability, and film-forming properties, as well as improving resistance to variation, the stretching is preferably performed at "film melting point -150°C" to "film melting point -40°C", particularly "film melting point -55°C" to "film melting point -40°C", at a stretching ratio of 1.40 or less (particularly 1.00 to 1.40 times, preferably 1.02 to 1.40 times) in both TD and MD, respectively, independently, more preferably 1.29 or less (particularly 1.00 to 1.29 times, preferably 1.02 to 1.29 times), and even more preferably 1.08 or less (particularly 1.00 to 1.08 times, preferably 1.02 to 1.08 times). In this case, the TD / MD ratio of the stretching ratio is preferably 1.02 to 1.25, more preferably 1.02 to 1.20, and even more preferably 1.02 to 1.15. If the stretching temperature is too high or too low, or the stretching ratio is too high or too low, at least one of the heat resistance, dimensional stability, mechanical properties, flexibility, uniformity, and processability is reduced. The stretching strain rate during stretching is not particularly limited, and may usually be 1 to 10% / sec, particularly 1 to 5% / sec, independently in both TD and MD.

[0086] In the simultaneous biaxial stretching method, the heat setting is preferably performed in two or more stages (particularly in two stages). When the heat setting is performed in two stages, the heat setting MT1 is usually performed before stretching, and is performed by holding at 50 to 250°C (particularly 70 to 200°C, preferably 100 to 200°C) for 1 to 300 seconds (particularly 3 to 120 seconds, preferably 0.5 to 2 minutes). The heat setting MT2 is usually performed after stretching, and is performed by holding at a temperature within the same range as the stretching temperature (particularly a temperature similar to the stretching temperature) for 5 to 300 seconds (particularly 10 to 120 seconds, preferably 0.5 to 2 minutes). The heat setting MT2 is preferably performed together with a relaxation treatment of several percent TD. Before the simultaneous biaxial stretching, the film may be subjected to a preliminary longitudinal stretching of more than 1 to about 1.20 times or less. If the stretching ratio exceeds 1.40, the tensile modulus in that direction becomes insufficient, resulting in reduced flexibility. When the film is used as a dicing film, the expandability of the silicon wafer in the expanding step becomes insufficient, which may result in frequent errors in the subsequent pick-up step, which is not preferable.

[0087] In the sequential biaxial stretching method, the heat setting treatment is the same as that in the simultaneous biaxial stretching method, and is usually preferably carried out in two or more stages (particularly in two stages). For example, the following methods A and B can be mentioned; Method A: heat setting M1, stretching in MD, then successively heat setting T1 again in a TD stretching machine, stretching in TD, and finally heat setting T2; and Method B: A method in which, without substantially performing stretching in the MD direction, a heat setting treatment T1 is performed in a TD stretching machine, followed by uniaxial stretching only in the TD direction and then a heat setting treatment T2.

[0088] In the sequential biaxial stretching method, when stretching is performed only uniaxially in the TD direction (method B), the heat setting temperature and time of heat setting T1 and heat setting T2, and the thermal relaxation conditions may be the same as those of heat setting MT1 and heat setting MT2 described in the simultaneous biaxial stretching method. The stretch ratio in TD in method B may be selected from the same range as the stretch ratios in MD and TD described in the simultaneous biaxial stretching method.

[0089] Furthermore, when stretching is also performed in MD before TD stretching (in the case of method A), the heat setting treatment conditions M1 are preferably 60 to 200°C for 2 to 300 seconds. In this case, the treatment temperature and treatment time of heat setting treatment T1 and heat setting treatment T2, and the heat relaxation treatment conditions may be the same as the conditions of heat setting treatment MT1 and heat setting treatment MT2 described in the simultaneous biaxial stretching method. The stretch ratios in MD and TD in method A may be selected from the same ranges as the stretch ratios in MD and TD described in the simultaneous biaxial stretching method.

[0090] In the simultaneous biaxial stretching method and the sequential biaxial stretching method, the temperature during the heat setting treatment and the stretching treatment may be the room temperature of the treatment chamber in which each treatment is performed. In the simultaneous biaxial stretching method and the sequential biaxial stretching method, the heating method during the heat setting treatment and the stretching treatment is not particularly limited, and may be a known method such as a method of blowing hot air, a method of irradiating infrared rays, a method of irradiating microwaves, a method of contacting with a heated roll, or the like.

[0091] When the unstretched film is made into the thermoplastic resin film of the present invention without stretching, the heat setting is the same as the heat setting in the sequential biaxial stretching method, and is usually performed in two or more stages (particularly two stages). When the unstretched film is heat set in two stages, the heat setting temperature and the heat setting time of the heat setting T1 and the heat setting T2 may be the same as the heat setting temperature and the heat setting time of the heat setting T1 and the heat setting T2 in the sequential biaxial stretching method.

[0092] When the unstretched film is used as the thermoplastic resin film of the present invention without stretching, the heat setting process does not necessarily have to be performed using the tenter-type stretching machine described above, and a pressurized conveying machine capable of pressurizing, heating, and cooling the film while continuously conveying it with upper and lower belts, such as a double belt press, can also be suitably used. The heat setting process usually causes shrinkage in the TD direction. What is common between the case where the heat setting process is performed using the tenter-type stretching machine described above and the case where the heat setting process is performed using the pressurized conveying machine described above is that the film cannot shrink in the TD direction due to the gripping force of the clips or the upper and lower belts. As a result, in either case, the same effect as that of stretching in the TD direction can be obtained, which contributes to improving the resistance to variation.

[0093] In the film manufacturing apparatus, the surfaces of the melting and measuring parts of the cylinder, barrel, single tube, filter, T-die, etc. are preferably subjected to a treatment to reduce the roughness of the surface in order to prevent the resin from stagnation. For example, a method of reducing the roughness of the surface may be used to modify the surface with a substance having low polarity. Alternatively, a method of depositing silicon nitride or diamond-like carbon on the surface may be used.

[0094] Specific methods for stretching the film include, for example, flat-type sequential biaxial stretching, flat-type simultaneous biaxial stretching, and tubular methods. Among them, it is preferable to adopt the flat-type simultaneous biaxial stretching from the viewpoint of improving the thickness accuracy of the film and making the MD properties of the film uniform.

[0095] Examples of the stretching device for employing the flat-type simultaneous biaxial stretching method include a screw-type tenter, a pantograph-type tenter, and a linear motor-driven clip-type tenter.

[0096] In order to increase the thermal stability during film formation, prevent deterioration of the strength and elongation of the film, and prevent deterioration of the film due to oxidation, decomposition, etc. during use, it is preferable to include a heat stabilizer in the thermoplastic resin film of the present invention. Examples of heat stabilizers include hindered phenol-based heat stabilizers, hindered amine-based heat stabilizers, phosphorus-based heat stabilizers, sulfur-based heat stabilizers, and bifunctional heat stabilizers. Among them, hindered phenol-based heat stabilizers are preferred, and Sumilizer GA-80 (registered trademark) (manufactured by Sumitomo Chemical Co., Ltd., 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane) is more preferred. When a heat stabilizer is used, the content is preferably 0.01 to 2 parts by mass, more preferably 0.04 to 1 part by mass, relative to 100 parts by mass of the thermoplastic resin, in order to more efficiently suppress thermal decomposition. The heat stabilizer may be added at any stage during the production of the film. For example, the heat stabilizer may be added during or before the melt mixing of the thermoplastic resin when producing an unoriented film.

[0097] The thermoplastic resin film of the present invention may contain lubricant particles to improve the slipperiness. Examples of lubricant particles include inorganic particles such as silica, alumina, titanium dioxide, calcium carbonate, kaolin, and barium sulfate, and organic fine particles such as acrylic resin particles, melamine resin particles, silicone resin particles, and crosslinked polystyrene particles. The lubricant particles may be added at any stage during the production of the film. For example, the lubricant particles may be added during or before the melt mixing of the thermoplastic resin during the production of the unstretched film.

[0098] The thermoplastic resin film of the present invention may contain various additives as necessary within the range that does not impair the effects of the present invention. Examples of additives include colorants such as pigments and dyes, coloring inhibitors, antioxidants different from the above-mentioned heat stabilizers, weather resistance improvers, flame retardants, plasticizers, release agents, reinforcements, modifiers, antistatic agents, ultraviolet absorbers, antifogging agents, and various polymers. Examples of pigments include titanium oxide and the like. Examples of weather resistance improvers include benzotriazole-based compounds and the like. Examples of flame retardants include bromine-based flame retardants and phosphorus-based flame retardants. Examples of reinforcers include talc and the like. The various additives may be added at any stage when producing a film. For example, the additives may be added during or before melt mixing of the thermoplastic resin when producing an unstretched film.

[0099] The thermoplastic resin film of the present invention may be subjected to a treatment for improving the adhesion of its surface, if necessary. Examples of the method for improving the adhesion include a corona treatment, a plasma treatment, an acid treatment, and a flame treatment.

[0100] The surface of the thermoplastic resin film of the present invention may be coated with various coating agents in order to impart functions such as easy adhesion, antistatic properties, releasability, and gas barrier properties.

[0101] The thickness of the thermoplastic resin film of the present invention must be 60 to 300 μm, preferably 65 to 250 μm, and more preferably 70 to 150 μm. If the thickness is less than 60 μm, the film will break during the expansion process when used as a dicing film, which is not preferable. On the other hand, if the thickness exceeds 300 μm, the tensile stress during the expansion process will be high, making it impossible to expand, which is not preferable.

[0102] The melting point of the thermoplastic resin film of the present invention is usually 270° C. or higher, and from the viewpoint of heat resistance, it is preferably 280° C. or higher, more preferably 290° C. or higher, and even more preferably 300° C. or higher. If the melting point is too low, the heat resistance is poor, and the film cannot withstand use as, for example, a dicing film.

[0103] The thermoplastic resin film of the present invention is excellent in heat resistance, and the dimensional change rate of the film at 260°C, which is one of the indicators of heat resistance, must be 10% or less in both MD and TD, and from the viewpoint of further improving heat resistance, it is preferably 8% or less, and more preferably 7% or less. If either the dimensional change rate in MD or TD exceeds 10%, when the film is used as a dicing film, delamination of the silicon wafer occurs during the reflow process. The lower limit of the dimensional change rate is not particularly limited, and the dimensional change rate may usually be 0.1% or more (particularly 1% or more).

[0104] In addition, the MD / TD ratio of the dimensional change rate at 260° C. must be 0.50 to 1.50, more preferably 0.65 to 1.35, even more preferably 0.65 to 1.30, and sufficiently preferably 0.80 to 1.20. If the MD / TD ratio of the dimensional change rate at 260° C. is less than 0.50 or exceeds 1.50, the MD and TD dimensional change rates become non-uniform, and therefore, when the film is used as a dicing film, delamination of the silicon wafer occurs during the reflow process.

[0105] The dimensional change rate of the thermoplastic resin film can be controlled by adjusting the production conditions of the film. For example, if the heat setting temperature is increased, the dimensional change rate increases, and if the heat setting temperature is decreased, the dimensional change rate decreases. Also, for example, if the stretching ratio is increased, the dimensional change rate decreases, and if the stretching ratio is decreased, the dimensional change rate increases.

[0106] The dimensional change rate in this specification is a value measured with a sample size of 5 mm×10 mm, a load of 40 mN, a scan range of 20 to 280° C., and a heating rate of 10° C. / min.

[0107] Furthermore, the variation in dimensional change rate at 260°C as shown in the following formula is usually 0 to 10% in both MD and TD, and from the viewpoint of further improving the variation resistance, it is preferably 0 to 5%, more preferably 0 to 3%, further preferably 0 to 2%, and sufficiently preferably 0 to 1.7%.

[0108] X MD Variance = X MD max-X MD min (A) X TD Variance = X TD max-X TD min (B)

[0109] In formula (A), X MD max is the maximum dimensional change rate in the MD direction at 260℃, X MD min indicates the minimum value of the dimensional change rate in the MD direction at 260°C. In formula (B), X TD max is the maximum dimensional change rate in the TD direction at 260℃, X TD min indicates the minimum value of the dimensional change rate in the TD direction at 260°C.

[0110] The thermoplastic resin film of the present invention has excellent tensile stress properties at low tensile elongation, and the stress at 30% elongation (F30), which is a criterion for tensile stress properties at low tensile elongation, must be 300N or less in both MD and TD, more preferably 200N or less, and even more preferably 150N or less. If the stress at 30% elongation exceeds 300N, when the film is used as a dicing film, the expandability of the dicing film in the expanding process may be insufficient, and frequent mistakes may occur in the subsequent pick-up process, which is not preferable. The lower limit of the F30 is not particularly limited, and the F30 may usually be 10N or more (particularly 30N or more).

[0111] In addition, the MD / TD ratio of the stress at 30% elongation must be 0.50 to 1.50, more preferably 0.65 to 1.35, even more preferably 0.65 to 1.30, and sufficiently preferably 0.80 to 1.20. If the MD / TD ratio of the stress at 30% elongation is less than 0.50 or exceeds 1.50, the stress at 30% elongation in MD and TD will be non-uniform, and therefore, when the film is used as a dicing film, the expandability of the dicing film in the expanding step will be insufficient, which may lead to frequent mistakes in the subsequent pick-up step, which is not preferable.

[0112] The stress at 30% elongation of a thermoplastic resin film can be controlled by adjusting the manufacturing conditions of the film. For example, if the stretching ratio is lowered, the stress at 30% elongation will be lower, and if the stretching ratio is increased, the stress at 30% elongation will be higher. In addition, if the film thickness is reduced, the stress at 30% elongation will be lower, and if the film thickness is increased, the stress at 30% elongation will be higher.

[0113] The stress at 30% elongation in this specification is the value measured in accordance with JIS K 7127 under conditions of temperature 20°C and humidity 65%, with a sample size of 10 mm × 150 mm, an initial distance between chucks of 100 mm, and a tensile speed of 500 mm / min.

[0114] The thermoplastic resin film of the present invention is excellent in flexibility, and the tensile modulus, which is a criterion for flexibility, must be 1.50 GPa or less in both MD and TD, more preferably 1.35 GPa or less, and even more preferably 1.20 GPa or less. If the tensile modulus exceeds 1.50 GPa, when the film is used as a dicing film, the expandability of the dicing film in the expanding process may be insufficient, and mistakes may occur frequently in the subsequent pick-up process, which is not preferable. The lower limit of the tensile modulus is not particularly limited, and the tensile modulus may usually be 0.1 GPa or more (particularly 0.2 GPa or more).

[0115] In addition, the MD / TD ratio of the tensile elastic modulus must be 0.50 to 1.50, more preferably 0.65 to 1.35, even more preferably 0.65 to 1.30, and sufficiently preferably 0.80 to 1.20. If the MD / TD ratio of F30 is less than 0.50 or exceeds 1.50, the tensile elastic modulus in MD and TD will be non-uniform, and therefore when the film is used as a dicing film, the expandability of the dicing film in the expanding step will be insufficient, which may lead to frequent mistakes in the subsequent pick-up step, which is not preferable.

[0116] The tensile modulus of the thermoplastic resin film can be controlled by adjusting the production conditions of the film. For example, a lower stretch ratio results in a lower tensile modulus, whereas a higher stretch ratio results in a higher tensile modulus.

[0117] The tensile modulus in this specification is a value measured in accordance with JIS K 7127 under conditions of a temperature of 20°C and a humidity of 65%, with a sample size of 10 mm × 150 mm, an initial distance between chucks of 100 mm, and a tensile speed of 500 mm / min.

[0118] The thermoplastic resin film of the present invention may be in the form of a sheet or may be wound around a winding roll to form a film roll. From the viewpoint of productivity when used for various applications, it is preferable to form the film roll. When formed into a film roll, it may be slit to a desired width.

[0119] The thermoplastic resin film of the present invention may be used as it is, or may be used to form a thermoplastic resin film laminate.

[0120] When the thermoplastic resin film of the present invention is used in the form of a laminate, the thermoplastic resin film laminate has the above-mentioned thermoplastic resin film of the present invention and at least one layer selected from the group consisting of a resin layer, a metal layer, and an inorganic material layer provided on the thermoplastic resin film.

[0121] The resin layer contains a thermoplastic resin. The thermoplastic resin constituting the resin layer is not particularly limited, and may be selected from the group consisting of, for example, polyimide, polyamideimide, polyetherimide, polyarylene ether ketone, polyarylene sulfide, fluorocarbon polymer, polyamide, polyester, polyether, polyolefin, polystyrene, polycarbonate, polyurethane, ethylene / vinyl acetate copolymer, ethylene / α-olefin copolymer, ethylene / acrylic acid ester copolymer, maleic anhydride modified polyolefin, and ionomer. When the resin constituting the resin layer is polyamide, the polyamide may be the polyamide constituting the thermoplastic resin film of the present invention, or may be another polyamide.

[0122] Examples of metals that can be used to form the metal layer include copper, aluminum, and iron.

[0123] Examples of inorganic materials that may be used to form the inorganic material layer include non-metals such as diamond and silicon, inorganic compounds (oxides, carbides, nitrides) such as silicon dioxide, alumina, zirconia, titanium oxide, barium titanate, silicon carbide, aluminum nitride, and gallium nitride, sapphire glass, and silicate glass.

[0124] The thermoplastic resin film and thermoplastic resin film laminate of the present invention are sufficiently excellent in heat resistance, dimensional stability, mechanical properties, flexibility, uniformity, processability and film formability, and are therefore useful in applications requiring at least one of these properties (preferably applications requiring all of these properties). For example, the thermoplastic resin film and thermoplastic resin film laminate of the present invention can be suitably used for molding and decoration materials (particularly decorative molding films) such as in-mold molding, film insert molding, vacuum molding, compressed air molding, and press molding; substrate films such as curved circuit boards, flexible printed circuit boards, curved antenna boards and flexible antenna boards; semiconductor process films (particularly dicing films) such as dicing film, dicing film integrated die attachment film (i.e. dicing-die attachment film), dicing film integrated die bonding film (i.e. dicing-die bonding film), dicing film integrated wafer back surface protection film, and back grinding film; and impact absorbing materials such as tube covering film, electric wire covering film, impact absorbing film, and sealing film.

[0125] The thermoplastic resin film of the present invention may be used as a film for decorative molding. When the thermoplastic resin film of the present invention is used as a film for decorative molding, the thermoplastic resin film of the present invention is used in the form of a single body or a laminate. The thermoplastic resin film as a film for decorative molding is capable of protecting or sealing the surface of an object, for example, by cold molding or hot molding. The thermoplastic resin film laminate as a film for decorative molding has a resin layer and / or a metal layer formed on the thermoplastic resin film, and is capable of imparting a pattern or functionality to the surface of a molded product, for example, by in-mold molding or film insert molding. When a metal layer is formed on the thermoplastic resin film laminate, for example, there is a method of forming a conductive circuit on the surface of the thermoplastic resin film, or a method of etching the metal layer of the thermoplastic resin film laminate to form metal wiring.

[0126] When the thermoplastic resin film of the present invention is used as a dicing film, the thermoplastic resin film of the present invention is used in the form of a thermoplastic resin film laminate. The thermoplastic resin film laminate as a dicing film has a resin layer (particularly an adhesive layer) formed on the above-mentioned thermoplastic resin film, and is capable of holding, for example, a semiconductor wafer.

[0127] When the thermoplastic resin film and the thermoplastic resin film laminate of the present invention are used for a flat or curved printed circuit board, the thermoplastic resin film and the thermoplastic resin film laminate of the present invention can be used by forming a conductive circuit on the surface of the thermoplastic resin film, or by etching the metal layer of the thermoplastic resin film laminate to form metal wiring. A flat or curved printed circuit board is a printed circuit board that may have a flat shape or a curved shape.

[0128] The thermoplastic resin film and the thermoplastic resin film laminate of the present invention may be used for a flat or curved antenna substrate. When the thermoplastic resin film and the thermoplastic resin film laminate of the present invention are used for a flat or curved antenna substrate, the thermoplastic resin film and the thermoplastic resin film laminate of the present invention can be used by forming a conductive circuit on the surface of the thermoplastic resin film or by etching the metal layer of the thermoplastic resin film laminate to form a metal wiring. EXAMPLES

[0129] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0130] A. Evaluation Methodology The thermoplastic resin films were evaluated by the following methods. (1) Resin composition of the film A few milligrams of the film was taken and analyzed using a high-resolution nuclear magnetic resonance apparatus (ECA-500NMR manufactured by JEOL Ltd.). 1The resin composition was determined from the peak intensity of each copolymer component by H-NMR analysis (resolution: 500 MHz, solvent: mixed solvent of deuterated trifluoroacetic acid and deuterated chloroform in a volume ratio of 4 / 5, temperature: 23° C.).

[0131] (2) Melt viscosity of resin raw material The resin raw material used was measured using a flow tester (CFT-500D) under the conditions of melting point +30°C preheating for 3 minutes, L / D = 10, and loads of 5kg to 100kg were selected at three points, using the method described in JIS K 7210-1. ―1 The value at which this occurs was taken as the melt viscosity of the resin raw material.

[0132] (3) Melting point of resin material or film A few milligrams of the obtained film was taken and heated to 350°C at a heating rate of 20°C / min using a differential scanning calorimeter DSC-7 (manufactured by PerkinElmer), then held at 350°C for 5 minutes, cooled to 25°C at a heating rate of 20°C / min, held at 25°C for a further 5 minutes, and then heated again at a heating rate of 20°C / min. The temperature based on the top of the endothermic peak when the temperature was increased again was taken as the melting point.

[0133] The melting point was evaluated according to the following criteria. <Evaluation criteria (melting point)> ◎: 290℃ or higher (excellent); ○: 280°C or higher but lower than 290°C (good); △: 270°C or higher and lower than 280°C (no practical problems); ×: Less than 270°C (problems in practical use).

[0134] (4) Crystallinity The unstretched film obtained was cut to a size of 150 mm x 150 mm, the four sides of the film were clipped using a KARO IV stretcher (Brueckner Maschinenbau), and the film was subjected to the same heat treatment as in heat setting treatment M1 and heat setting treatment T1 (MT1). Using a differential scanning calorimeter DSC-7 (PerkinElmer), the temperature was increased from room temperature to 350°C at a heating rate of 20°C / min, and the degree of crystallinity was calculated using the heat due to crystallization by heating (ΔTc) and the heat of fusion (ΔTm) according to the following formula. Crystallinity = (ΔTc / ΔTm)×100[%]

[0135] (5) Dimensional change rate of film at 260℃ Using a thermomechanical analyzer TMA-7100 manufactured by Shimadzu Corporation, the dimensional change rate at the time of reaching 260°C was read with a sample size of 5mm x 10mm, load of 40mN, scan range of 20-280°C, and heating rate of 10°C / min. The dimensional change rate is the ratio (%) of the dimension at the time of reaching 260°C to the dimension at the start of measurement. For the measurement, 5mm x 10mm samples were taken at three positions corresponding to 25, 50, and 75% from the end of the full width in the width direction of the original fabric. In addition, at each of the three locations shown above, 5 mm x 10 mm samples were taken at 15 locations at 200 m intervals in the machine direction of the original fabric, and the dimensional change rates in the MD and TD were measured for a total of 45 samples (n=3). Calculate the maximum, minimum, and average values ​​of TD, and TD max, X TD min, X TD ave, calculate the maximum, minimum, and average values ​​of MD, and MD max, X MD min, X MD ave, and the variations in TD and MD were calculated using the following formula. X TDばらつき =X TD max-X TD min(A) X MDばらつき =X MD max-X TD min(B)

[0136] Dimensional change rate in MD direction (X MD ave), dimensional change rate in TD direction (X TD ave), MD / TD ratio (X MD ave / X TD ave), MD direction dimensional change variation (X MDばらつき ) and dimensional change variation in the TD direction (X TDばらつき ) was evaluated according to the following criteria: <Evaluation criteria: Heat resistance and dimensional stability> X MD ave, X TD ave ◎: 7.0% or less (excellent); ○: More than 7.0% and 8.0% or less (good); △: More than 8.0% and 10.0% or less (no problem in practical use); ×: More than 10.0% (problems in practical use). The ratio of [dimensional change rate (MD) / dimensional change rate (TD)] was evaluated according to the following criteria.

[0137] <Evaluation criteria: Heat resistance uniformity> X MD ave / X TD ave ◎: 0.80 or more and 1.20 or less (excellent); ○: 0.65 or more but less than 0.80 and 1.20 or more but less than 1.30 (good); △: 0.50 or more but less than 0.65 and 1.30 or more but less than 1.50 (no problem in practical use); ×: Less than 0.50 and more than 1.50 (problems in practical use).

[0138] <Evaluation criteria: Tolerance to variation> X MDばらつき、 X TDばらつき ◎: Less than 2% excellent; ○: More than 2%, less than 3% excellent; △: More than 3%, less than 5% good; ▲: Over 5% and 10% or less. No practical problems. ×: More than 10% is problematic in practical use.

[0139] (6) Stress at 30% elongation of film (F30), tensile modulus Using Shimadzu Corporation's AGS-X, measurements were taken at the center of the original film in accordance with JIS K 7127 under conditions of temperature 20°C and humidity 65%. Sample size: 10mm x 150mm, initial distance between chucks: 100mm, tensile speed: 500mm / min. Measurements were taken at n=10 using 10 samples taken at 10 random locations on the film, and the average values ​​were taken as the stress at 30% elongation (F30) and tensile modulus of elasticity. F30 was calculated as the tensile stress in MD and TD when the distance between chucks was 130mm.

[0140] F30(MD) and F30(TD) were evaluated according to the following criteria. <Evaluation criteria: mechanical properties> ◎: 150N or less (excellent); ○: More than 150N and less than 200N (good); △: Over 200N and up to 300N (no practical problems); ×: Exceeds 300N (problems in practical use).

[0141] The [F30(MD) / F30(TD)] ratio was evaluated according to the following criteria. <Evaluation criteria: Mechanical uniformity> ◎: 0.80 or more and 1.20 or less (excellent); ○: 0.65 or more but less than 0.80 and 1.20 or more but less than 1.30 (good); △: 0.50 or more but less than 0.65 and 1.30 or more but less than 1.50 (no problem in practical use); ×: Less than 0.50 and more than 1.50 (problems in practical use).

[0142] The tensile modulus (MD) and tensile modulus (TD) were evaluated according to the following criteria. <Evaluation criteria: flexibility> ◎: 1.20GPa or less (excellent); ○: More than 1.20 GPa and 1.40 GPa or less (good); △: More than 1.40 GPa and less than 1.50 GPa (no practical problems); ×: Exceeds 1.50 GPa (problems in practical use).

[0143] The [tensile modulus (MD) / tensile modulus (TD)] ratio was evaluated according to the following criteria. <Evaluation criteria: flexibility uniformity> ◎: 0.80 or more and 1.20 or less (excellent); ○: 0.65 or more but less than 0.80 and 1.20 or more but less than 1.30 (good); △: 0.50 or more but less than 0.65 and 1.30 or more but less than 1.50 (no problem in practical use); ×: Less than 0.50 and more than 1.50 (problems in practical use).

[0144] (7) Processing suitability An adhesive was applied to the thermoplastic resin film of the present invention, a tape fixing frame and a silicon wafer were attached to the adhesive-coated surface, the silicon wafer was cut with a dicing blade, and then an expansion process in which pressure was applied from the side not coated with adhesive was carried out n=50 times, the number of breaks was counted, and evaluation was performed according to the following criteria. <Evaluation criteria> ◎:0 times (excellent); ○: 1 time (good); △: 2 to 5 times (no practical problems); ×: 5 times or more (problems in practical use).

[0145] (8) Film forming properties (thickness unevenness) The thickness of the film was measured at 10 points every 10 mm from the center of the film toward the MD using a thickness gauge (HEIDENHAIN-METRO MT1287) manufactured by HEIDENHAIN Co., Ltd. Then, the thickness unevenness was calculated based on the following formula and evaluated based on the following criteria. T ave :Average thickness T max : Maximum thickness T min : Minimum thickness Thickness unevenness (%) = [(T max -T min ) / T ave ] x 100 <Evaluation criteria> ◎: Less than 5%; ○: 5% or more and less than 7.5%; △: 7.5% or more and less than 10%; ×: 10% or more.

[0146] (9) Overall rating All the evaluation results (all evaluation results related to items other than the resistance to variation) related to the above-mentioned heat resistance (melting point and heat-resistant dimensional stability), flexibility, mechanical properties, uniformity (heat-resistant uniformity, mechanical uniformity, and flexibility uniformity), processability, and film-forming property were evaluated comprehensively. More specifically, the lowest evaluation result among all these evaluation results was used as the result of the comprehensive evaluation.

[0147] B. Raw materials The following raw materials were used: Dimer acid (C36): Cargill Pripol 1009 Dimer acid (C44): Cargill Pripol 1004 Terephthalic acid: Dimer diamine (C36): Cargill Priamine 1075 1,10-Decanediamine: 1,9-Nonanediamine: 2-Methyl-1,8-octanediamine: Sodium hypophosphite: ·Benzoic acid:

[0148] The thermoplastic resin used was prepared as follows. ·Thermoplastic resin P1 32.9 parts by mass of terephthalic acid and 0.1 parts by mass of sodium hypophosphite monohydrate were charged into a ribbon blender-type reaction apparatus, and heated to 170°C while stirring at a rotation speed of 30 rpm under nitrogen sealing. Thereafter, while maintaining the temperature at 170°C and the rotation speed at 30 rpm, 34.3 parts by mass of 1,10-decanediamine heated to 100°C was continuously added (continuous liquid injection method) using a liquid injection device over 2.5 hours to obtain a reaction product. The molar ratio of the raw material monomers was terephthalic acid:1,10-decanediamine=49.9:50.1. 16.8 parts by mass of dimer acid (C36) and 15.9 parts by mass of dimer diamine were added to a reaction vessel equipped with a heating mechanism and a stirring mechanism. After stirring at 100°C for 1 hour, the above reaction product was added while stirring. The mixture was then heated to 260°C while stirring, and polymerization was carried out for 5 hours at 260°C under normal pressure under a nitrogen stream while removing condensed water from the system. During polymerization, the system was in a state of a suspended solution. After polymerization was completed, the mixture was discharged, cut, and dried to obtain thermoplastic resin P1 in the form of pellets. The melting point of this thermoplastic resin was 305°C.

[0149] ·Thermoplastic resin P2 Into a ribbon blender type reactor, 37.6 parts by mass of dimer acid (C36), 35.7 parts by mass of dimer diamine, 13.0 parts by mass of terephthalic acid, 13.5 parts by mass of 1,10-decanediamine, and 0.1 parts by mass of sodium hypophosphite monohydrate were added. Then, the mixture was heated to 260°C with stirring, and polymerization was carried out for 5 hours at normal pressure and 260°C under a nitrogen stream while removing condensed water from the system. During polymerization, the system was in a suspended state. After polymerization was completed, the mixture was discharged, cut, and dried to obtain a thermoplastic resin P2 in the form of pellets. The melting point of this thermoplastic resin was 302°C.

[0150] ·Thermoplastic resin P3~P4 Thermoplastic resins P3 to P4 were obtained in the same manner as for thermoplastic resin P1, except that the amounts of terephthalic acid, 1,10-decanediamine, dimer acid (C36), and dimer diamine added were changed as shown in Table 1. The melting points of these thermoplastic resins P3 and P4 were 300°C and 308°C, respectively.

[0151] ·Thermoplastic resin P5 Thermoplastic resin P5 was obtained in the same manner as thermoplastic resin P1, except that the amounts of terephthalic acid, 1,10-decanediamine, dimer acid (C44), and dimer diamine were changed as shown in Table 1. The melting points of each were 305°C.

[0152] ·Thermoplastic resin P6 49.7 parts by mass of terephthalic acid, 40.2 parts by mass of 1,9-nonanediamine, 10.0 parts by mass of 2-methyl-1,8-octanediamine, 0.1 parts by mass of sodium hypophosphite monohydrate, and 2200 parts by mass of distilled water were placed in a reactor and purged with nitrogen. The molar ratio of the raw material monomers was terephthalic acid:1,9-nonanediamine:2-methyl-1,8-octanediamine=99.0:80.0:20.0. The contents of the reactor were stirred at 100°C for 30 minutes, and the internal temperature was raised to 210°C over 2 hours. At this time, the pressure inside the reactor was raised to 2.12MPa. After continuing the reaction for 1 hour, the temperature was raised to 230°C, and then the temperature was kept at 230°C for 2 hours, and the reaction was continued while gradually removing steam and maintaining the pressure at 2.12MPa. Next, the pressure was lowered to 0.98MPa over 30 minutes, and the reaction was continued for another hour to obtain a prepolymer. This was dried under reduced pressure at a temperature of 100°C for 12 hours, and then crushed to a size of 2mm or less. The crushed prepolymer was then solid-phase polymerized for 10 hours under conditions of a temperature of 230°C and a pressure of 13.3Pa. This was fed to a twin-screw extruder, melt-kneaded and extruded under conditions of a cylinder temperature of 320°C, and cut and dried to produce thermoplastic resin P5 in the form of pellets. The melting point of this thermoplastic resin was 300°C.

[0153] ·Thermoplastic resin P7 66.7 parts by mass of pellets of thermoplastic resin P4, 33.3 parts by mass of pellets of thermoplastic resin P3, and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. The mixture was then cooled and cut to obtain thermoplastic resin P6 in pellet form. The melting point of this thermoplastic resin was 305°C.

[0154] ·Thermoplastic resin P8 80 parts by mass of pellets of thermoplastic resin P6, 20 parts by mass of pellets of thermoplastic resin P2, and 0.4 parts by mass of Sumilizer GA-80 were dry-blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. The mixture was then cooled and cut to obtain thermoplastic resin P7 in pellet form. The melting point of this thermoplastic resin was 298°C.

[0155] ·Thermoplastic resin P9 53.3 parts by mass of pellets of thermoplastic resin P6, 46.7 parts by mass of pellets of thermoplastic resin P2, and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. The mixture was then cooled and cut to obtain thermoplastic resin P8 in pellet form. The melting point of this thermoplastic resin was 295°C.

[0156] ·Thermoplastic resin P10 33.3 parts by mass of thermoplastic resin P6 pellets, 66.7 parts by mass of thermoplastic resin P2 pellets, and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. The mixture was then cooled and cut to obtain thermoplastic resin P9 in pellet form. The melting point of this thermoplastic resin was 290°C.

[0157] ·Thermoplastic resin P11 56.7 parts by mass of thermoplastic resin P6 pellets, 33.3 parts by mass of thermoplastic resin P2 pellets, 10 parts by mass of TAFMER MH7020, and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. After that, it was cooled and cut to obtain thermoplastic resin P11 in pellet form. The melting point of this thermoplastic resin was 295°C.

[0158] ·Thermoplastic resin P12 56.7 parts by mass of thermoplastic resin P6 pellets, 33.3 parts by mass of thermoplastic resin P3 pellets, 10 parts by mass of TAFMER MH7020, and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. After that, it was cooled and cut to obtain thermoplastic resin P12 in pellet form. The melting point of this thermoplastic resin was 295°C.

[0159] ·Thermoplastic resin P13 80 parts by mass of thermoplastic resin P6 pellets, 20 parts by mass of OKY pellets, and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. The mixture was then cooled and cut to obtain thermoplastic resin P13 in pellet form. The melting point of this thermoplastic resin was 297°C.

[0160] ·Thermoplastic resin P14 80 parts by mass of thermoplastic resin P6 pellets, 20 parts by mass of PRIT30 pellets, and 0.4 parts by mass of Sumilizer GA-80 were dry-blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. The mixture was then cooled and cut to obtain thermoplastic resin P14 in pellet form. The melting point of this thermoplastic resin was 297°C.

[0161] ·Thermoplastic resin P15 80 parts by mass of thermoplastic resin P6 pellets, 20 parts by mass of EVOLUE (SP0510) pellets, and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330°C, melt-kneaded, and extruded into a strand shape. The mixture was then cooled and cut to obtain thermoplastic resin P15 in pellet form. The melting point of this thermoplastic resin was 296°C.

[0162] Table 1 shows the charged compositions and polymerization methods of the obtained thermoplastic resins P1 to P6, and the final compositions of the thermoplastic resins P1 to P15.

[0163] [Table 1]

[0164] Example 1 100 parts by mass of pellets of thermoplastic resin P1 and 0.4 parts by mass of Sumilizer GA-80 were dry blended, fed into a twin-screw extruder with a screw diameter of 26 mm and a cylinder temperature of 330° C., melt-kneaded, and extruded into a strand shape, which was then cooled and cut to obtain pellets. The obtained pellets were put into a single-screw extruder (screw diameter 50 mm) heated to a cylinder temperature of 330°C and melted to obtain a molten polymer. The molten polymer was filtered using a metal fiber sintered filter (manufactured by Nippon Seisen Co., Ltd., "NF-13", nominal filtration diameter: 60 μm). The molten polymer was then extruded into a film shape from a T-die adjusted to a temperature of 330°C and a lip width of 1.0 mm to obtain a film-like molten material, which was then brought into contact with a cooling roll set at 0°C by an electrostatic application method and cooled to obtain a substantially unoriented unstretched thermoplastic resin film. At this time, t die , t film are 1200μm, 60μm, and t die / t film The viscosity was 20.0. The thickness of the obtained film was 100 μm. The resin composition of the thermoplastic resin component of the obtained unstretched thermoplastic resin film was determined to be the same as the resin composition of the thermoplastic resin used. The obtained substantially unoriented unstretched film was put into an MD stretching machine, passed through without heating or stretching, and put into a TD stretching machine. At this time, in the MD stretching machine, MD stretching was not substantially performed, and heat setting treatment T1 was performed at 80°C for 60 seconds, and then in the TD stretching machine, TD stretching was not substantially performed, and heat setting treatment T2 was performed at 260°C for 60 seconds to obtain an unstretched film.

[0165] Examples 2 to 5, 11 to 17, Comparative Examples 1 to 4 Except for changing the production conditions of the resin and film as shown in Table 2 or Table 3, pellets were prepared in the same manner as in Example 1, an unstretched film was obtained, and a thermoplastic resin film was obtained by heat setting treatment.

[0166] Example 6 The substantially unoriented unstretched thermoplastic resin film obtained in Example 1 (the unstretched film before being fed into the MD stretching machine) was subjected to heat setting treatment MT1 at 80°C for 60 seconds, and then simultaneous biaxial stretching was performed at a stretching temperature of 260°C with an MD stretch ratio of 1.03 times and a TD stretch ratio of 1.05 times, and further heat setting treatment MT2 was performed at 260°C for 60 seconds to obtain a simultaneous biaxially stretched thermoplastic resin film.

[0167] Examples 7 to 9, Comparative Examples 5, 6, and 7 Except for changing the resin and film production conditions as shown in Table 2 or Table 3, pellets were prepared in the same manner as in Example 6, an unstretched film was obtained, and heat-set and simultaneous biaxial stretching were performed to obtain a thermoplastic resin film.

[0168] Example 10 The substantially unoriented unstretched thermoplastic resin film obtained in Example 1 (unstretched film before being fed into the MD stretching machine) was fed into the MD stretching machine, passed through without heating or stretching, and fed into the TD stretching machine. After being fed into the TD stretching machine, heat setting treatment T1 was carried out at 80°C for 60 seconds, uniaxial stretching was carried out only in the TD direction at a stretching temperature of 260°C and a stretch ratio of 1.10 times, and further heat setting treatment T2 was carried out at 260°C for 60 seconds to obtain a thermoplastic resin film.

[0169] Examples 18 to 24, 26 to 27 A thermoplastic resin film was obtained in the same manner as in Example 10, except that the production conditions of the resin and film were changed as shown in Table 3.

[0170] Example 25 The substantially unoriented unstretched thermoplastic resin film obtained in Example 1 (unstretched film before being put into the MD stretching machine) was put into the MD stretching machine, and heat setting treatment M1 was carried out under the conditions of 100°C x 20 seconds, followed by MD stretching at a ratio of 1.05 times, and then put into the TD stretching machine. After being put into the TD stretching machine, heat setting treatment T1 was carried out at 80°C x 20 seconds, TD stretching was carried out at a stretching temperature of 200°C at a ratio of 1.05 times, and further heat setting treatment T2 was carried out at 220°C x 60 seconds to obtain a thermoplastic resin film.

[0171] The production conditions and physical properties of the thermoplastic resin films obtained in Examples 1 to 27 and Comparative Examples 1 to 7 are shown in Tables 2 and 3.

[0172] [Table 2]

[0173] [Table 3]

[0174] The films of Examples 1 to 27 were produced with a draft ratio of 1.0 to 20.0 and a stretching ratio of 1.3 or less in both MD and TD, and therefore had excellent dimensional change at 260°C, stress at 30% elongation, tensile modulus, uniformity of the above-mentioned property values, and processability.

[0175] The film of Comparative Example 1 was produced at a draft ratio of 20 or more, and therefore had a large TD / MD ratio of dimensional change at 260° C., TD / MD ratio of stress at 30% elongation, and TD / MD ratio of tensile modulus. The film of Comparative Example 2 was produced at a draft ratio of 1 or less, and therefore had a large dimensional change rate in the MD at 260° C. and a large TD / MD ratio. The film of Comparative Example 3 had a thickness of less than 60 μm and therefore had poor processability. The film of Comparative Example 4 had a thickness exceeding 300 μm, and therefore had large stresses at 30% elongation in both TD and MD. The film of Comparative Example 5 was stretched at a stretching ratio of 2.30 in both TD and MD, and therefore had large tensile moduli in both TD and MD. The film of Comparative Example 6 was stretched at a stretching ratio of 1.50 in both TD and MD, and therefore had large tensile moduli in both TD and MD. The film of Comparative Example 7 had a large resistance to variation because the temperature of the heat setting treatment MT1 was low and the crystallinity of the film before stretching was low. [Industrial Applicability]

[0176] The thermoplastic resin film of the present invention is useful, for example, as a dicing film used in semiconductor manufacturing, a base film such as an adhesive tape, a transfer film for decoration and molding, and a cushion film during pressing. The dicing film is, in detail, a film for holding a plurality of divided semiconductor wafers together in the manufacturing of semiconductors. More specifically, the dicing film is attached to a silicon wafer, and then subjected to a dicing process for dividing the silicon wafer, an expanding process for uniformly expanding the chip intervals by radially stretching the dicing film, and a picking up process for picking up each divided chip with a needle or the like, and then peeled off.

Claims

1. A thermoplastic resin film that satisfies the following requirements (1) to (4): (1) The thickness is 60 to 300 μm; (2) The dimensional change rate at 260°C is 10% or less in both MD and TD, and the [dimensional change rate (MD) / dimensional change rate (TD)] ratio is 0.50 to 1.50; (3) The stress at 30% elongation (F30) in a tensile test is 300 N or less in both MD and TD, and the [F30 (MD) / F30 (TD)] ratio is 0.50 to 1.50; (4) The tensile modulus of elasticity is 1.50 GPa or less in both MD and TD, and the ratio of [tensile modulus of elasticity (MD) / tensile modulus of elasticity (TD)] is 0.50 to 1.

50.

2. The thermoplastic resin film according to claim 1, which satisfies the following requirements (1') to (4'): (1') The thickness is 65 to 250 μm; (2') the dimensional change rate at 260°C is 8% or less in both MD and TD, and the [dimensional change rate (MD) / dimensional change rate (TD)] ratio is 0.65 to 1.30; (3') the stress at 30% elongation (F30) in a tensile test is 200 N or less in both MD and TD, and the [F30 (MD) / F30 (TD)] ratio is 0.65 to 1.30; (4') The tensile modulus of elasticity is 1.35 GPa or less in both MD and TD, and the ratio of [tensile modulus of elasticity (MD) / tensile modulus of elasticity (TD)] is 0.65 to 1.

30.

3. The thermoplastic resin film according to claim 1, which satisfies the following requirements (1'') to (4''). (1'') the thickness is 70 to 150 μm; (2'') the dimensional change rate at 260°C is 7% or less in both MD and TD, and the [dimensional change rate (MD) / dimensional change rate (TD)] ratio is 0.80 to 1.20; (3'') the stress at 30% elongation (F30) in a tensile test is 150 N or less in both MD and TD, and the [F30 (MD) / F30 (TD)] ratio is 0.80 to 1.20; (4'') The tensile modulus is 1.20 GPa or less in both MD and TD, and the ratio of [tensile modulus (MD) / tensile modulus (TD)] is 0.80 to 1.

20.

4. The thermoplastic resin film according to claim 1 , wherein the variation in dimensional change rate, as represented by the following formula, is 5% or less. X ＭＤ Variation = X ＭＤ max-X ＭＤ min (A) X ＴＤ Variation = X ＴＤ max-X ＴＤ min (B) (X in formula (A) ＭＤ max is the maximum dimensional change rate in the MD direction at 260 ° C., X ＴＤ minX ＭＤ min indicates the minimum value of the dimensional change rate in the MD direction at 260 ° C., and X in the formula (B) ＴＤ max is the maximum dimensional change rate in the TD direction at 260 ° C., X ＴＤ min indicates the minimum value of the dimensional change rate in the TD direction at 260°C.)

5. The thermoplastic resin film contains a thermoplastic resin, and the thermoplastic resin is melted at a temperature of 30° C. above its melting point and at a temperature of 1000 s above its melting point. －１ The thermoplastic resin film according to claim 1, having a melt viscosity at a shear rate of 30 to 300 mPa·s.

6. A thermoplastic resin film laminate comprising the thermoplastic resin film according to any one of claims 1 to 5.

7. A dicing film using the thermoplastic resin film according to any one of claims 1 to 5.

8. A dicing film using the thermoplastic resin film laminate according to claim 6.

9. A method for producing a thermoplastic resin film, comprising a film-forming step of melt-mixing a thermoplastic resin and an additive added as required, extruding the melt into a sheet through a T-die, bringing the melt into close contact with a drum, and taking and cooling the sheet to obtain an unstretched film, and further comprising or not including a stretching step of stretching the unstretched film, The outlet gap of the T-die during film production (t ｄｉｅ ) (μm) and the film thickness at the time of drum withdrawal (t ｆｉｌｍ The draft ratio (t ｄｉｅ / t ｆｉｌｍ ) is 1.0 to 20.0, A method for producing a thermoplastic resin film, wherein the stretching ratio is independently 1 to 1.40 times in both MD and TD.

10. The method for producing a thermoplastic resin film according to claim 9 , wherein the unstretched film has a crystallinity of 65% or more.

11. A method for producing the thermoplastic resin film according to claim 9 or 10, which produces the thermoplastic resin film according to claim 1.

12. The draft ratio (t ｄｉｅ / t ｆｉｌｍ ) is 3.0 to 15.0, The method for producing a thermoplastic resin film according to claim 9, wherein the stretching ratio is independently 1 to 1.29 times in both MD and TD.

13. The method for producing a thermoplastic resin film according to claim 12, wherein the unstretched film has a crystallinity of 80% or more.

14. A method for producing the thermoplastic resin film according to claim 12 or 13, which produces the thermoplastic resin film according to claim 2.

15. The draft ratio (t ｄｉｅ / t ｆｉｌｍ ) is 8.0 to 15.0, The method for producing a thermoplastic resin film according to claim 9, wherein the stretching ratios in both MD and TD are independently 1 to 1.08 times.

16. The method for producing a thermoplastic resin film according to claim 15, wherein the unstretched film has a crystallinity of 83% or more.

17. A method for producing the thermoplastic resin film according to claim 15 or 16, which produces the thermoplastic resin film according to claim 3.

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