JP2006152072A - Anti-static film for producing semiconductor and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anti-static film that is used in semiconductor devices having excellent expanding property, optical transparency enabling the use of UV ray-curable adhesive and can be utilized for semiconductor devices. <P>SOLUTION: This is an anti-static film formed from a polyester block copolymer of a thickness of 10 to 500 μm, in which (i) the polyester block copolymer comprises 30 to 50 wt.% of a hard segment and 70 to 30 wt.% of a soft segment on the basis of 100 wt.% of the block copolymer, where (ii) the hard segment comprising more than 50 mol% of the terephthalic acid component or naphthalene dicarboxylic acid component on the basis of 100 mol% of the dicarboxylic acid components, and more than 70 mol% of tetramethylene glycol component on the basis of 100 mol% of the glycol component, while the soft segment is composed of the poly(alkylene oxide) glycol component. Further, a method for producing the same is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antistatic film used in the manufacture of semiconductor devices. Specifically, the present invention is such a film made of a specific polyester block copolymer. With this block copolymer, such a film has very good antistatic performance, has a good expanding property that stretches evenly with little force and is difficult to sag, and uses an ultraviolet curable pressure-sensitive adhesive. It has possible light transmission. Films having such characteristics are useful in the manufacture of various semiconductor devices, and are particularly useful as base films for adhesive films for dicing for attaching and holding materials when semiconductor wafers are cut and separated into semiconductor chips. The present invention relates to the substrate film.

  In the manufacturing process of a semiconductor device typified by silicon and gallium arsenide, various films are used for the purpose of fixing and protecting the device. Typically, there is an adhesive film used in a dicing process and other processes. For example, in the dicing process, a semiconductor wafer such as a silicon wafer on which a predetermined circuit pattern is formed is cut and separated into individual chips, that is, in order to perform a die-sync operation reliably and easily, the silicon wafer is attached to an adhesive film, Thereafter, an operation of dicing is performed. Such an adhesive film as a semiconductor wafer fixing film is usually called a dicing film, a dicing tape, or a dicing sheet. After the dicing step, usually high-pressure water washing is performed, and then the semiconductor chip cut and separated is picked up from the adhesive sheet and transferred to the next die bonding step.

  Between the washing step and the pick-up step, in order to facilitate normal pick-up, (i) a step of curing the pressure-sensitive adhesive by irradiation with ultraviolet rays from the film substrate side and reducing its adhesive strength; and (ii) Thereafter, the film is expanded, that is, stretched in the vertical and horizontal directions to increase the distance between the semiconductor chips.

  Conventionally, a soft polyvinyl chloride resin film (hereinafter sometimes simply referred to as a PVC film) has been used as a base film of a dicing film so that this process can be easily performed. However, since the PVC film has a large environmental load at the time of incineration disposal, there is a problem that the cost at the time of disposal tends to increase, and various plasticizers contained in the film easily contaminate the semiconductor wafer.

Furthermore, the dicing film is required to have good antistatic performance in order to avoid the adverse effect on the semiconductor wafer due to static electricity. Such static electricity is generated when the release paper is peeled off from the film, during the dicing process, during the cleaning process, and during pickup.
Various proposals have been made for dicing films using a base film instead of a PVC film.

  A substrate film for dicing film using a non-crystalline polyester resin having a Tg of 0 to 50 ° C. is known (see Patent Document 1). Since the film has good light transmittance, it is effective for use of an ultraviolet curable adhesive. Further, this document describes that it is preferable to have a specific storage elastic modulus and loss tangent (tan δ) in order to prevent defects during pick-up and chip disturbance. As a specific example of such a polyester resin, an amorphous polyester which is considered to be copolymerized with polytetramethylene glycol is exemplified, but the technical content is unclear.

Under the concept of achieving the same strength and elongation as a PVC film with a polyester film, a base film for a dicing film made of polyester having a specific Young's modulus and elongation value based on polyethylene terephthalate has been proposed and is known. (See Patent Document 2). This document has a specific example of a soft polyester copolymerized with a polyalkylene glycol component.
However, further improved antistatic performance and expanding properties are sought from the above. Furthermore, the light transmittance which an ultraviolet curing adhesive acts effectively is also calculated | required.

  As a base film for a dicing film using a transparent thermoplastic elastomer, a base film having a specific tensile property and a restoration rate is known which is made of a resin composition made of polypropylene and a styrene-isoprene block copolymer. Yes (see Patent Document 3). However, this document does not disclose an effective technique for improving the antistatic performance.

  As the dicing film provided with the antistatic function, for example, the following techniques are known. A technique for imparting antistatic property to a dicing tape base film by mixing conductive particles such as carbon black with the base film is known (see Patent Documents 4 and 5). Although this technique allows a significant reduction in surface resistance, its application is likely to be limited in that it is opaque.

  A technique of providing an antistatic layer on either side of the base film or mixing a polymer antistatic agent in the base film is known (see Patent Document 6). However, the method of separately providing the antistatic layer tends to increase the number of manufacturing steps and cost. Further, when better antistatic performance is required, it is preferable that the base film itself has antistatic performance. In addition, the method of mixing an antistatic agent with the base polymer tends to be inferior in antistatic performance or adversely affect the expanding properties. Further, when an ionic material is used, the semiconductor chip is liable to be adversely affected.

JP 2003-92273 A JP 2003-342393 A JP 2002-60708 A JP 2001-351879 A Japanese Patent Application Laid-Open No. 10-069771 JP 09-190990 A

  As is apparent from the above, when the dicing film is required to further improve the antistatic performance, the conventional technology still cannot provide a sufficient film. The present invention has been made in view of such circumstances, and its purpose is to have extremely good antistatic performance, to have a good expanding property that is uniformly stretched with a slight force and hardly sags, and An object of the present invention is to provide an antistatic film that is used in the production of a semiconductor device and has a light-transmitting property capable of using an ultraviolet curable adhesive.

  As a result of intensive studies, the present inventors have obtained knowledge that the above object can be easily achieved by a film made of a polyester block copolymer in which a specific component is combined. Arrived. In addition, although the film utilized at the time of manufacture of a semiconductor device is called a film, a sheet | seat, a tape, etc. by a use, if the film of this invention is satisfied that it is a specific thickness, all these material forms will be included.

  According to the present invention, the object is (1) an antistatic film for semiconductor production having a thickness of 10 to 500 μm formed from a polyester block copolymer, and (i) the polyester block copolymer is 100 wt. 30% to 70% by weight of a hard segment and 70% to 30% by weight of a soft segment, and (ii) the polyester of the hard segment is 50 mol% or more of terephthalic acid based on 100 mol% of a dicarboxylic acid component. A component or a naphthalenedicarboxylic acid component and 70 mol% or more of a tetramethylene glycol component based on 100 mol% of a diol component, and (iii) the soft segment is composed of a poly (alkylene oxide) glycol component It is achieved by the antistatic film for semiconductor production.

  Here, “for semiconductor production” in the present invention means that it is used during production of a semiconductor. Specific examples of the antistatic film for semiconductor production include a film for fixing a semiconductor wafer represented by the dicing tape as described above, a back grind tape, and the like. The film of the present invention exhibits excellent antistatic performance without containing other additives by being formed from a specific polyester block copolymer.

  In the present invention, the description “aa component” (“aa” indicates a compound name) related to the structural unit in the polyester block copolymer is derived from the compound “aa” or an ester-forming derivative thereof. The polymer structural unit is shown. For example, the dicarboxylic acid component indicates a structural unit derived from dicarboxylic acid or an ester-forming derivative thereof, and the diol component indicates a structural unit derived from a diol compound or an ester-forming derivative thereof. The ester-forming derivative of dicarboxylic acid is typically an alkyl ester of such acid, and methyl ester is particularly preferably used.

  One of the preferred embodiments of the present invention is that (2) the poly (alkylene oxide) glycol component contains 50 poly (ethylene oxide) glycol components having a number average molecular weight of 1,500 to 10,000 in 100% by weight. It is the antistatic film for semiconductor manufacture of the said structure (1) containing a weight% or more. According to such a configuration, it is possible to achieve both better antistatic performance and expanding characteristics.

  One of the preferred embodiments of the present invention is that (3) the hard segment polyester comprises 85 to 95 mol% terephthalic acid component and 5 to 15 mol% isophthalic acid component based on 100 mol% dicarboxylic acid component. An antistatic film for semiconductor production having the above-mentioned constitutions (1) to (2). According to such a configuration, both good rubber elasticity and ultraviolet ray permeability are compatible, and as a result, a film that is excellent in expanding properties and suitable for curing an ultraviolet curable pressure-sensitive adhesive is achieved.

  One of the preferred embodiments of the present invention is as follows. (4) The above-described structure (1) in which the film satisfies the total light transmittance measured in accordance with JIS K7105 in the range of 99.5 to 60%. ) To (3) of an antistatic film for semiconductor production. The polyester block copolymer of the present invention satisfies the above light transmittance in the film thickness, and has sufficient ultraviolet transparency to cure the pressure-sensitive adhesive in a pressure-sensitive adhesive film laminated with a UV-curable pressure-sensitive adhesive. That is, although it is a film that cannot be said to be sufficiently transparent, it has good ultraviolet light transmittance. The total light transmittance is more preferably 70% or more, still more preferably 80% or more, while more preferably 99% or less, and still more preferably 98% or less.

One of the preferred embodiments of the present invention is that (5) The film has a surface resistivity of 10 ⁸ to 10 ¹² Ω and satisfies the constitutions (1) to (4) for semiconductor production. It is a preventive film. The antistatic film for semiconductor production of the present invention has good antistatic performance, but more preferably, the range of the surface specific resistance value is adjusted to 10 ⁸ to 10 ¹⁰ Ω.

  One of the preferred embodiments of the present invention is that (6) the antistatic film for manufacturing a semiconductor is a base film of a film for fixing a semiconductor wafer, and the antistatic for manufacturing a semiconductor according to any one of the above constitutions (1) to (5). It is a sex film. The film of the present invention is excellent in antistatic properties, expanding properties, and ultraviolet transmittance, and is suitable as a base film for a film for fixing a semiconductor wafer, which requires all of these properties.

  One of preferred embodiments of the present invention is: (7) The semiconductor wafer fixing film is characterized in that a photocurable acrylic pressure-sensitive adhesive layer is provided on one surface of the base film (6) ) For producing semiconductors. The film for fixing a semiconductor wafer is provided with an adhesive layer for adhering the semiconductor to the film. Such a pressure-sensitive adhesive layer is cured before the pickup process to facilitate the pickup. Examples of such curing modes include photocuring, thermal curing, and pressure curing. The antistatic film of the present invention can be applied to any curing mode pressure-sensitive adhesive layer. The semiconductor wafer fixing film provided with the pressure-sensitive adhesive layer has good antistatic properties and expanding properties. Among the pressure-sensitive adhesives, photocurable pressure-sensitive adhesives are preferable because they are more excellent in the efficiency of semiconductor chip manufacturing. Since the antistatic film for semiconductor production according to the present invention is excellent in ultraviolet light transmittance, the characteristics of the photocurable pressure-sensitive adhesive are sufficiently exhibited. In particular, a photocurable acrylic pressure-sensitive adhesive is preferably used for the semiconductor wafer fixing film of the present invention.

Furthermore, according to another aspect of the present invention, the object is (8) a method for producing an antistatic film for semiconductor production,
(I) a step of preparing pellets comprising a polyester block copolymer, wherein (i) the polyester block copolymer comprises 30 to 70% by weight of a hard segment and 70 to 30% by weight of a soft segment. And (ii) the hard segment polyester comprises 50 mol% or more of a terephthalic acid component or naphthalenedicarboxylic acid component based on 100 mol% of a dicarboxylic acid component and 70 mol based on 100 mol% of a diol component. And (iii) the soft segment comprises a poly (alkylene oxide) glycol component (step-i), comprising:
(II) supplying pellets made of the polyester block copolymer to an extruder and discharging a molten resin body from a flat die (step-ii),
(III) The molten resin body is cooled with a cooling roll by nipping pressure or single-sided touch method, and has a thickness of 20 to 200 μm and a total light transmittance of 99.5 to 60% measured in accordance with JIS K7105. And a step of obtaining a solid film having a surface resistivity of 10 ⁸ to 10 ¹² Ω (step-iii), and (IV) a step of winding the film without interposing a process release paper (step- iv)
And (9) an antistatic film for semiconductor production produced by the production method of the configuration (8).

The details of the present invention will be further described below.
<About polyester block copolymer>
The polyester block copolymer of the present invention is a block copolymer composed of a high melting point polyester segment called a hard segment and a low melting point polymer segment called a soft segment.

  Further, the polyester block copolymer of the present invention comprises (i) the polyester block copolymer comprising 30 to 70% by weight of a hard segment and 70 to 30% by weight of a soft segment, and (ii) The hard segment polyester comprises a terephthalic acid component or naphthalenedicarboxylic acid component in excess of 50 mol% based on 100 mol% dicarboxylic acid component, and 70 mol% or more tetramethylene glycol component based on 100 mol% diol component. And (iii) the soft segment is composed of a poly (alkylene oxide) glycol component.

  The hard segment polyester is preferably a polyester containing 50 mol% or more, more preferably 70 mol% or more, and further preferably 80 mol% or more of terephthalic acid based on 100 mol% of the dicarboxylic acid component.

  Examples of the dicarboxylic acid for deriving the naphthalenedicarboxylic acid component of the hard segment polyester include 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. Ester-forming derivatives can be used. Of these, 2,6-naphthalenedicarboxylic acid and its ester-forming derivatives are preferred.

  Further, the hard segment polyester may contain a dicarboxylic acid component other than the terephthalic acid component and the naphthalenedicarboxylic acid component. Examples of the acid that derives the dicarboxylic acid component include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, diphenyldicarboxylic acid, bis (4-carboxyphenyl) methane, diphenoxyethanedicarboxylic acid, and bis (4-carboxyphenyl) sulfone. And aliphatic dicarboxylic acids such as adipic acid, sebacic acid, azelaic acid, and decanedicarboxylic acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. Other dicarboxylic acid components are introduced into the hard segment polyester by these acids and ester-forming derivatives thereof.

  A more preferred embodiment of the hard segment polyester is a polyester in which an isophthalic acid component is copolymerized. Among them, a preferred embodiment is preferably 85 to 95 mol%, more preferably 88 to 92 mol% of terephthalic acid component, preferably 5 to 15 mol%, more preferably 8 based on 100 mol% of the dicarboxylic acid component. A polyester comprising ˜12 mol% of isophthalic acid component.

  The hard segment polyester contains 70 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more of the tetramethylene glycol component based on 100 mol% of the diol component.

  The hard segment polyester of the present invention may contain other diol components. Examples of diols that derive such other diol components include ethylene glycol, trimethylene glycol, propylene glycol, neopentyl glycol, hexamethylene glycol, aliphatic diols such as decamethylene glycol and dodecamethylene glycol, diethylene glycol, and cyclohexanedimethanol. Such alicyclic diols, 2,2-bis (4-β-hydroxyethoxyphenyl) propane, p-xylylene glycol, and aromatic diols such as alkylene oxide adducts of bisphenol A, and bisphenols and hydroquinone Examples are monohydric phenols.

  Furthermore, the polyester of the hard segment can also contain a compound containing a trifunctional or higher functional carboxyl group or hydroxyl group as its structural unit. Examples of the trifunctional or higher functional carboxyl group-containing compound include trimellitic acid, trimesic acid, and pyromellitic acid. Examples of the trifunctional or higher functional hydroxyl group-containing compound include glycerin, trimethylpropane, pentaerythritol, trimethanolbenzene, and triethanol. Examples include benzene. Such a trifunctional or higher functional carboxyl group-containing compound is used in a total amount of 100 mol% with respect to the dicarboxylic acid component, preferably 1 mol% or less.

  The preferred hard segment polyester in the polyester block copolymer of the present invention is based on polytetramethylene terephthalate. The dicarboxylic acid component of the polyester may be replaced with another dicarboxylic acid component in the above-mentioned proportion, and particularly preferably a copolymer of a terephthalic acid component and an isophthalic acid component having the above-mentioned proportion. On the other hand, the diol component of the polyester may be replaced with other diol components in the above-described proportions. Such polytetramethylene terephthalate has good crystallinity, imparts good rubber elasticity, light transmission, and chemical resistance to the polyester block copolymer.

  The soft segment in the polyester block copolymer of the present invention comprises a poly (alkylene oxide) glycol component. Such poly (alkylene oxide) glycols include, for example, poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (trimethylene oxide) glycol, poly (tetramethylene oxide) glycol, and poly (hexamethylene oxide) glycol. Examples thereof include polyalkylene ether glycols such as, and copolymer polyether glycols obtained by copolymerizing components of these polyalkylene ether glycols. Such a copolymer may be any of a block copolymer, a random copolymer, and a graft copolymer. Furthermore, the poly (alkylene oxide) glycol component can be contained in the polyester block copolymer in two or more kinds.

  The number average molecular weight of the poly (alkylene oxide) glycol component is suitably 300 to 100,000, preferably 1,500 to 10,000, more preferably 2,000 to 5,000. Such a polyester block copolymer having a number average molecular weight of less than 300 is not preferred because it may reduce the heat resistance of the film and may cause a bleed out of a low molecular weight product. On the other hand, such a polyester block copolymer having a number average molecular weight of more than 100,000 is not preferable because the polymerization itself is difficult and the production efficiency is liable to be reduced, and the characteristic variation due to the poor dispersion of the soft segment is likely to occur.

  When a plurality of polyalkylene ether glycol components having different molecular weights are used in combination, the average number average molecular weight may be in the above range. In addition, said number average molecular weight means the value computed based on the calibration line obtained from the GPC measurement standard substance of polyethyleneglycol and / or polyethylene oxide by the gel permeation chromatography method (GPC method). The measurement conditions of the standard substance and the sample are as follows: Column: G3000PWXL × 2 (manufactured by Tosoh Corporation), elution solvent: 20 mM phosphate buffer, detector: differential refractometer, flow rate: 0.5 mL / min, sample solution usage : 10 μL, and column temperature: 45 ° C. are employed.

  The poly (alkylene oxide) glycol component in the polyester block copolymer is preferably a poly (ethylene oxide) glycol component or a poly (tetramethylene oxide) glycol component. A more preferred poly (alkylene oxide) glycol component contains 50% by weight or more of a poly (ethylene oxide) glycol component having a number average molecular weight of 1,500 to 10,000 in 100% by weight. The number average molecular weight is more preferably 2,000 to 5,000. The ratio of the poly (ethylene oxide) glycol component in the poly (alkylene oxide) glycol component is more preferably 60% by weight or more, and particularly preferably 70% by weight or more. On the other hand, the upper limit of the proportion of the poly (ethylene oxide) glycol component is 100% by weight, preferably 95% by weight, more preferably 90% by weight. That is, it is preferable that a small proportion of other poly (alkylene oxide) glycol components, particularly poly (tetramethylene oxide) glycol components are used in combination. Such a combination is effective for adjusting the expanding characteristics of the film.

  Content of the said hard segment in the polyester block copolymer of this invention is 30 to 70 weight% in a 100 weight% copolymer, Preferably it is 40 to 60 weight%, More preferably, it is 45 to 55 weight%. On the other hand, the content of the soft segment is 70 to 30% by weight, preferably 60 to 40% by weight, more preferably 55 to 45% in a 100% by weight copolymer corresponding to the content of the hard segment. %. With such a content, good antistatic properties, expanding properties, and ultraviolet transmittance are combined.

  Furthermore, the logarithmic viscosity value (IV value) of the polyester block copolymer of the present invention is preferably 0.6 or more, more preferably in the range of 0.7 to 1.6, and still more preferably in the range of 0.8 to 1.2. . The IV value is the value measured at 35 ° C. in o-chlorophenol. If the IV value exceeds the above range and is too low, the strength is undesirably low. Moreover, if IV value is 1.6 or less, in manufacture of a polyester block copolymer and a film, it will become excellent in manufacturing efficiency.

<Method for producing polyester block copolymer>
The polyester block copolymer is produced by a batch method or a continuous method according to a conventional method for producing a polyester resin, for example, a direct polymerization method or a transesterification method. Such a polyester block copolymer comprises (a) terephthalic acid or naphthalenedicarboxylic acid as an essential component thereof, and ester-forming derivatives thereof, tetramethylene glycol and ester-forming derivatives thereof, and poly (alkylene oxide) glycol and esters thereof. A process for producing a polycondensation derivative of a forming derivative, and (b) an oligomer having a low polymerization degree comprising a dicarboxylic acid component and a diol component in advance, and the oligomer, poly (alkylene oxide) glycol and ester forming property thereof You may manufacture by any method of the method of manufacturing by making a derivative and a polycondensation reaction. In the present invention, the polyester block copolymer produced by the former method (a) can be used more preferably. In addition, optional components other than the essential components can be added at any stage of the polycondensation reaction process.

  The copolymer obtained by the polycondensation reaction is usually extracted in a strand form from an extraction port provided at the bottom of the polycondensation reaction tank, and is cut into a pellet by cutting with a cutter while cooling with water or with water. The Furthermore, by subjecting the pellets after polycondensation to solid-phase polycondensation by heat treatment, the degree of polymerization can be further increased, and reaction by-products such as acetaldehyde and low-molecular oligomers can be reduced. The shape of the pellet is not particularly limited, and may be a general shape such as a cylinder, a prism, or a sphere. The size of the pellet is preferably in the range of 1 to 10 mm in maximum length.

  In the above production method, the esterification reaction is carried out in the presence of an esterification catalyst such as antimony trioxide, an organic acid salt such as antimony, titanium, magnesium, calcium, or an organic metal compound, if necessary. be able to. In addition, the transesterification reaction can be performed in the presence of an ester exchange catalyst such as an organic acid salt or an organic metal compound such as lithium, sodium, potassium, magnesium, calcium, manganese, titanium, or zinc, if necessary. .

  The polycondensation reaction of the polyester block copolymer can be carried out in the presence of a phosphorus compound such as orthophosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid, esters thereof, and organic acid salts. Furthermore, the polycondensation reaction of such a copolymer can be carried out by using metal oxides such as diantimony trioxide, germanium dioxide, and germanium tetroxide, or organic acid salts and organic metals containing antimony, germanium, zinc, titanium, cobalt, and the like. The reaction can be performed in the presence of a polycondensation catalyst such as a compound. Examples of such polycondensation catalysts include germanium compounds such as germanium dioxide, germanium tetraethoxide, and germanium tetra n-butoxide, antimony compounds such as antimony trioxide, and titanium compounds such as titanium tetrabutoxide. One or more selected from tetrabutoxide, antimony trioxide, and germanium dioxide are preferably used.

  The antistatic film for semiconductor production according to the present invention is preferably produced by a method in which a molten resin obtained by T-die extrusion is cooled with a casting drum to form a film without substantially stretching as described later. In such a production method, in order to improve the production efficiency, peelability from the casting drum, so-called roll-off property, is important. If the roll-off property is poor, the film is wound on the casting drum side and it is difficult to increase the production speed. As a method for preventing such wrapping, there is a method in which the process release paper is interposed, but the use of the process release paper is not always preferable in consideration of production cost, environmental load and the like. In the present invention, as the antistatic performance is improved, the resin tends to be softened. As a result, the roll-off property is deteriorated. That is, the characteristics required for the semiconductor wafer fixing film and the productivity of the base film are contradictory characteristics.

  According to the study by the present inventors, when the polyester block copolymer having a relatively high crystallinity is mixed in a small amount with respect to such a problem, a film having a good roll-off property can be obtained while suppressing the deterioration of the antistatic performance and the expanded property. It turns out that it is obtained.

  Therefore, a more preferred polyester block copolymer of the present invention is as follows. The dicarboxylic acid component of the hard segment polyester is a polyetherester block copolymer comprising a terephthalic acid component and an isophthalic acid component, and the copolymer is referred to as “copolymer-i”. A polyether ester block copolymer in which a component is a polyether ester block copolymer composed only of a terephthalic acid component and such a copolymer is referred to as “copolymer-ii” is preferred. Here, based on the total of 100 parts by weight of copolymer-i and copolymer-ii, the proportion of copolymer-i is preferably 60-99 parts by weight, more preferably 80-95 parts by weight. The proportion of copolymer-ii is preferably 40 to 1 part by weight, more preferably 5 to 20 parts by weight. In both of the copolymers -i and -ii, the preferred embodiment of the diol component is as described above, and it is particularly preferable that 90 mol% or more of the tetramethylene glycol component is contained. Moreover, the preferable ratio of the terephthalic acid component and the isophthalic acid component in the copolymer-i is also as described above. Such a mixture provides an antistatic film for semiconductor production that is also excellent in roll release during production.

<Other additives>
Furthermore, the polyester block copolymer of the present invention provides inorganic or organic particles in order to impart blocking resistance, slipperiness, etc., in a range where the effect is exhibited, particularly in a range where there is no hindrance to use as a dicing film. It can be included. Examples of such inorganic particles include silica, alumina, titania, kaolin, clay, calcium carbonate, calcium phosphate, calcium fluoride, and carbon black. Furthermore, examples of the inorganic particles include precipitates resulting from the catalyst of alkali metal, alkaline earth metal, and phosphorus compound during polyester polymerization. On the other hand, as the organic particles, for example, various cross-linked polymers are typically exemplified and preferable. Numerous proposals have been made regarding the fine particles for imparting such blocking resistance and slipperiness in the field of polyester films, and these can also be applied in the present invention.

  The polyester block copolymer of the present invention can contain various additives in a range where the effects of the present invention are exhibited, in particular, in a range that does not hinder use as a dicing film.

  Examples of such additives include other thermoplastic resins. Such resins include polyolefin resins, polyamide resins, polycarbonate resins, other thermoplastic resins such as aromatic vinyl monomer-derived homopolymer and copolymer resins, and thermoplastic elastomers other than the polyester block copolymer of the present invention. And poly (alkylene oxide) glycol that is not copolymerized with the polyester block copolymer. Examples of the polyolefin resin include polyethylene, polypropylene, a copolymer of ethylene and propylene, and a copolymer of these with an α-olefin having 4 to 10 carbon atoms. These polymers may be modified with an acid compound such as maleic anhydride. The polyolefin resin contains an ionomer. Such other thermoplastic resin is preferably 10% by weight or less, more preferably 5% by weight or less, based on 100% by weight of the resin constituting the film.

  Further, the above additives include antioxidants such as hindered phenols, phosphites, and thioethers, benzotriazoles, benzophenones, benzoates, hydroxyphenyl triazines, cyclic imino esters, and cyanos. UV absorbers such as arylates, light stabilizers such as hindered amines, fluorescent colorants such as fluorescent brighteners and fluorescent dyes, inorganic and organic crystal nucleating agents, molecular weight modifiers, hydrolysis-resistant agents, lubricants, Illustrative examples include additives such as mold release agents, plasticizers, flame retardants, flame retardant aids, foaming agents, colorants, and dispersion aids. Furthermore, reinforcing materials, such as a small amount of glass fiber, carbon fiber, mica, talc, wollastonite, and potassium titanate whisker, are exemplified as necessary. Such various additives are usually mixed by melt-kneading with the polyester block copolymer, but can also be added in the polycondensation step of the copolymer.

<Film production method>
Next, the manufacturing method of the film of this invention is demonstrated. A pellet made of the polyester block copolymer is prepared. After drying the pellets as necessary, the pellets are extruded at a temperature of 200 to 300 ° C. using an extruder, and then rapidly cooled on a casting drum to obtain an unstretched film. Moreover, the method of obtaining a film similarly using a vent-type extruder, without drying a pellet, can also be utilized, and this method can be utilized more preferably at the point which can simplify a process. For drying the pellets, a hopper dryer, a paddle dryer, a vacuum dryer, or the like can be used. Moreover, you may use an inflation method for manufacture of a film.

  When any other component is blended in the polyester block copolymer, a method using a pellet in which the other component is previously contained, and the other component is directly supplied to the film forming extruder to block the block copolymer. Any method of uniform mixing with coalescence can be used.

  A flat die, a so-called T die, is preferably used as the die of the film forming extruder. As the T die, those having various structures used for manufacturing a normal sheet such as a manifold die, a fish tail die, and a coat hanger die are used. The molten resin extruded from the T-die is cooled with a single or a plurality of casting drums by a nipping pressure or single-sided touch method, and formed into a film without substantially stretching, thereby producing an unstretched film. Manufactured. In casting, a sheet with less thickness unevenness can be obtained by using a so-called electrostatic contact method, an air knife method, or a suction chamber method.

  Furthermore, for the purpose of stabilizing winding during film formation and preventing blocking after film formation, a method of laminating a film by stacking process release papers can also be used. As the process release paper, a stretched polyester sheet usually called O-PET and a stretched polypropylene sheet usually called OPP, a process release paper made of paper, or a process in which an olefin resin or silicone is coated on paper Release paper and the like are preferably exemplified.

  However, since the polyester block copolymer of the present invention has excellent antistatic performance while having flexible properties, it can provide an easy-to-handle film without using process release paper. Therefore, a more preferable production method of the film of the present invention includes a step of winding the film without interposing a process release paper, and more preferably the production method of the above-described configuration (8).

  Although the production speed of the film of the present invention is not particularly limited, for example, production at a take-up speed of 10 to 50 m / sec is exemplified. A more preferable production speed is 20 to 45 m / sec, and further preferably 25 to 40 m / sec. In the polyester block copolymer in which copolymer-i and copolymer-ii are mixed, which is a more preferred embodiment of the present invention, such production rate can be applied without using process release paper.

  The film can be subjected to various surface treatments such as corona discharge treatment, chemical treatment, and flame treatment on one side or both sides during or after the film formation process. By these surface treatments, for example, the adhesiveness between the film and the pressure-sensitive adhesive and the adhesiveness with other layers can be adjusted. The antistatic film for semiconductor production of the present invention preferably has an adhesive layer on at least one surface thereof, but a layer other than the adhesive layer can also be provided between the other surface or the adhesive layer. Examples of such a layer include an adhesive improvement layer with a pressure-sensitive adhesive, another antistatic layer, and an easy-sliding layer. In particular, on the surface opposite to the pressure-sensitive adhesive layer, slipperiness is often required in order to make the expand smoother. Therefore, it is preferable to provide a slippery layer on the surface.

  As described above, the antistatic film for semiconductor production of the present invention is laminated with various other functional layers in the form of final use. Such a functional layer may be laminated in an in-line manner in the above-described production method of the film of the present invention to be a base film, or may be laminated using another line after winding the base film once. You can also

Moreover, although the description of the manufacturing method of the said film mainly demonstrated the method by a single material, the film of this invention may have a multilayer structure. For example, by providing a polyester block copolymer containing a poly (alkylene oxide) glycol component at a high concentration in the surface layer and a copolymer having a low concentration of the component in the inner layer, antistatic performance and the hardness required for the film are required. It is also possible to adjust. Further, according to such a method, the polyester block copolymer of the present invention is provided on the surface layer, and a layer having other similar mechanical properties but not antistatic performance is provided. A preventive film can also be produced. Such a film is included as one embodiment of the present invention as long as similar properties are obtained with the polyester block copolymer of the present invention. However, compared with these laminated films, a single layer film is more preferable in that the characteristics required for a single material can be satisfied at a high level and manufacturing and disposal thereof are easy.
In addition, when extruding a multilayer film, a known coextrusion method can be employed.

<Semiconductor wafer fixing film>
The antistatic film for semiconductor production of the present invention is suitable for a base film of a film for fixing a semiconductor wafer as described in the configuration (6). Such a film for fixing a semiconductor wafer is usually provided with an adhesive layer for fixing the wafer. As the pressure-sensitive adhesive layer, conventionally known photo-curing, heat-curing and pressure-curing pressure-sensitive adhesives can be used, and a photo-curable acrylic pressure-sensitive adhesive layer is particularly suitable. Various adhesives are also known and can be used in the present invention.

  Usually, the photocurable acrylic pressure-sensitive adhesive is blended in an acrylic pressure-sensitive adhesive with 1 to 150 parts by weight of the photopolymerizable prepolymer and / or photopolymerizable monomer with respect to 100 parts by weight of the pressure-sensitive adhesive. Further, a crosslinking agent and a photopolymerization initiator are added. If necessary, a tackifier and a plasticizer are further blended to adjust the adhesiveness before and after curing, the expanded characteristics, the handleability during production, and the like. In the present invention, the photo-curing property or photo-polymerizing property means a property of radical polymerization by excitation and activation by light irradiation, but the wavelength of such light is not particularly limited. Therefore, either visible light or ultraviolet light may be used, and further radiation can be used. Preferably, ultraviolet light is used, and an ultraviolet curable or ultraviolet polymerizable component is preferred.

The acrylic pressure-sensitive adhesive used as the base of the photocurable acrylic pressure-sensitive adhesive is specifically an acrylic polymer selected from homopolymers and copolymers having an acrylic ester as the main constituent monomer unit, Copolymers with functional monomers and mixtures of these polymers. Examples of the acrylate ester include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, and 2-hydroxyethyl acrylate. Further, those obtained by replacing the acrylic ester with, for example, a methacrylic ester can be preferably used. Furthermore, other vinyl compounds and vinylidene compounds such as acrylic acid, methacrylic acid, acrylonitrile, vinyl acetate, and vinylidene chloride can be copolymerized with acrylic acid ester or methacrylic acid ester. The weight average molecular weight of the acrylic pressure-sensitive adhesive serving as the substrate is preferably 5 × 10 ⁴ to 2 × 10 ⁶ , more preferably 4 × 10 ⁵ to 8 × 10 ⁵ . The molecular weight is calculated from a calibration line using a standard polystyrene sample using the GPC method.

  The photopolymerizable prepolymer and / or the photopolymerizable monomer is a polyfunctional compound having at least two photopolymerizable carbon-carbon double bonds. The weight average molecular weight of the photopolymerizable prepolymer is preferably 5,000 to 50,000, more preferably 10,000 to 50,000. The molecular weight per photopolymerizable carbon-carbon double bond in the photopolymerizable prepolymer and / or photopolymerizable monomer is preferably in the range of 200 to 400, more preferably 220 to 350. The photopolymerizable monomer is preferably used in combination with a photopolymerizable prepolymer. Examples of the monomer include trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate, 1,4-butylene glycol diacrylate, and 1,6-hexane. Examples include diol diacrylate.

  A photo-curing acrylic pressure-sensitive adhesive crosslinking agent is used to adjust the adhesion and cohesion. Examples of such crosslinking agents include polyvalent isocyanate compounds, polyvalent epoxy compounds, polyvalent aziridine compounds, chelate compounds, and the like. Specific examples of the polyvalent isocyanate compound include toluylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and those adduct types. Specific examples of the polyvalent epoxy compound include ethylene glycol diglycidyl ether and terephthalic acid diglycidyl ester acrylate. Specific examples of the polyvalent aziridine compound include tris-2,4,6- (1-aziridinyl) -1,3,5-triazine, tris [1- (2-methyl) -aziridinyl] phosphine oxide, and hexa [1- (2-Methyl) -aziridinyl] triphosphatriazine and the like are used. As the chelate compound, specifically, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like are used. The crosslinking agent is blended in an amount of 0.05 to 15 parts by weight, preferably 0.1 to 12 parts by weight, based on 100 parts by weight of the polymer of the acrylic pressure-sensitive adhesive.

  Moreover, as a photoinitiator of a photocurable acrylic adhesive, a benzoin photoinitiator, a benzophenone photoinitiator, a thioxanthone photoinitiator, etc. are illustrated typically. Examples of commonly used benzoin photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and 2,2-dimethoxy-2-phenylacetophenone. The photopolymerization initiator is blended in an amount of 5 parts by weight or less, preferably 0.1 to 3 parts by weight based on 100 parts by weight of the acrylic adhesive polymer.

  Furthermore, conventionally known tackifiers can be used, and examples thereof include rosin resins, rosin ester resins, terpene resins, terpene phenol resins, and phenol resins. Also, conventionally known plasticizers can be used, such as phthalic acid esters, fatty acid esters, and phosphoric acid esters.

  The photocurable acrylic pressure-sensitive adhesive is usually dissolved in a solvent typified by toluene, ethyl acetate, tetrahydrofuran, and methyl ethyl ketone to prepare a pressure-sensitive adhesive solution. By applying the solution to the antistatic film of the present invention and then drying, the pressure-sensitive adhesive layer is laminated on the base film, and a product represented by a film for fixing a semiconductor wafer is obtained. For the application, conventionally known methods such as a roll coater, a die coater, and a knife coater are used. For the lamination of the pressure-sensitive adhesive layer, a method of separately laminating the pressure-sensitive adhesive layer on another release film and then laminating it with the antistatic film of the present invention and transferring the pressure-sensitive adhesive layer can be used.

  For curing the photocurable acrylic pressure-sensitive adhesive, ultraviolet rays in the range of 200 to 380 nm are usually used. As such an ultraviolet ray source, a mercury arc, a low pressure / medium pressure / high pressure mercury lamp, an ultraviolet LED, or the like can be used. By such irradiation, the adhesive force is usually reduced to about 1/10 to 1/30, and the semiconductor chip can be easily picked up.

  According to the present invention, there is provided a semiconductor wafer fixing film for a large semiconductor wafer represented by a silicon wafer having a diameter of 300 mm, which is currently mainstream. Furthermore, the film for fixing a semiconductor wafer of the present invention can be suitably applied to a thin semiconductor wafer having a thickness of about 10 to 50 μm. In the production of such a large or thin semiconductor wafer, good expanding properties are more required, and the advantages of the film for fixing a semiconductor wafer of the present invention are more effectively exhibited. The film for fixing a semiconductor wafer of the present invention can be used for manufacturing semiconductor chips of various sizes. For example, it can be used for manufacturing a semiconductor chip of 1 mm square or less called a so-called mu chip. Even in the production of such ultra-small chips, good antistatic properties and expanding properties are more required. In addition to the widely used blade dicing method, the semiconductor wafer dicing method forms a dicing line while selectively forming a modified layer by irradiating a laser inside the semiconductor wafer, and the modified layer is A method of dividing the chip by growing it vertically can be used.

  The antistatic film for semiconductor production according to the present invention is excellent in antistatic properties, expanding properties, and ultraviolet transmittance, and is suitable as a base film for a film for fixing a semiconductor wafer that generally requires any of these properties. is there. In particular, as described above, it is useful for a base film of a semiconductor wafer fixing film represented by a dicing film. In particular, a semiconductor wafer fixing film in which a photocurable acrylic pressure-sensitive adhesive layer is provided on one surface of the base film is suitable. In addition, since the antistatic film of the present invention has optical transparency, it can be suitably used as a cover tape for carrier tape from the viewpoint of easy identification of the contents.

  The form of the present invention considered to be the best by the present inventors is a collection of the preferable ranges of the above requirements. For example, typical examples are described in the following examples. Of course, the present invention is not limited to these forms.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to a following example, unless the summary is exceeded.
(I) Evaluation of base film (i) Measurement of surface resistance value The surface resistivity of the base film was measured using a super insulation meter (SM-8210, manufactured by Toa Denpa Kogyo Co., Ltd.). These tests were performed at an ambient temperature of 23 ° C. and a relative humidity of 50% after conditioning the sample for 24 hours in an atmosphere of a temperature of 23 ° C. and a relative humidity of 50%.
(Ii) Measurement of tensile modulus Tensile tester possessing 98N load cell conducts a tensile test at a chuck distance of 50 mm, a sample width of 25 mm, and a tensile speed of 10 mm / min. The force during the measurement was measured. The tensile elastic modulus was calculated from the stress required for 10% elongation during that time. In this calculation, the cross-sectional area of the film was calculated on the assumption that there was no change from the initial stage.
(Iii) Measurement of Tensile Breaking Strength and Elongation Using a tensile tester having a 98N load cell, 50 mm between chucks, 25 mm sample width, 200 mm / min. The tensile test was conducted to determine the strength until the base material layer was broken as the tensile breaking strength. The elongation at break was determined by (distance between chucks at break / 50 mm) × 100 = (elongation)%.
(Iv) Measurement of total light transmittance (JIS K7105)
The total light transmittance of the base film was measured using a Nippon Denshoku Co., Ltd. haze meter NDH-300A.

(II) Evaluation with a dicing film (i) Expanded characteristics and chip breakage during pick-up After dicing, ultrapure water cleaning, and expansion, microscopic observation is performed in this state, and there is no scattering or disturbance of chips during expansion. In addition, the semiconductor chip picked up with a vacuum collet was inspected and observed for the presence or absence of chip destruction, and the presence or absence of electrostatic breakdown of the chip was confirmed. Further, scattering and disturbance of other chips when picking up the chips and the presence or absence of adhesive residue on the chips were observed. The case where there was no problem in any item was evaluated as ◯, the case where it was slightly inferior was evaluated as Δ, and the case where it was insufficient in either case was evaluated as ×.
(Ii) Productivity Costs and processes were compared and evaluated as “good” for those having excellent productivity and “poor” for those having poor productivity.
(Iii) Environmental compatibility The evaluation was ○ for those that are easy to dispose and recycle, and × for those that generate chlorine gas during incineration and are difficult to recycle.

(Raw materials used)
Polyetherester block copolymer-1: “Nuberan TR-EKV” (trade name) manufactured by Teijin Chemicals Limited. Such a block copolymer consists of 48 wt% hard segment and 52 wt% soft segment, the hard segment comprising 44 mol% terephthalic acid component and 6 mol% isophthalic acid component and 46 mol% tetramethylene. It consists of a glycol component and 4 mol% ethylene glycol component, the soft segment consists of 100 mol% polyethylene oxide glycol component with a number average molecular weight of 4000, and its IV value is 1.20.

Polyetherester block copolymer-2: “Nuberan TR-ELK” (trade name) manufactured by Teijin Chemicals Limited. Such a block copolymer comprises 41% by weight hard segment and 59% by weight soft segment, the hard segment comprising 50 mol% terephthalic acid component and 50 mol% tetramethylene glycol component, Consists of 50 mol% of a polyethylene oxide glycol component having a number average molecular weight of 4000 and 50 mol% of a polyethylene oxide glycol component having a number average molecular weight of 2000, and its IV value is 1.50.

Polyether ester block copolymer-3: “Nuberan TR-EL1” (trade name) manufactured by Teijin Chemicals Limited. Such a block copolymer comprises 41% by weight hard segment and 59% by weight soft segment, the hard segment comprising 50 mol% terephthalic acid component and 50 mol% tetramethylene glycol component, Consists of 100 mol% polytetramethylene oxide glycol component with a number average molecular weight of 2000, and its IV value is 1.53.

Polyetherester block copolymer-4: “Nuberan TR-EL6” (trade name) manufactured by Teijin Chemicals Limited. Such a block copolymer comprises 79% by weight hard segment and 21% by weight soft segment, the hard segment comprising 50 mol% terephthalic acid component and 50 mol% tetramethylene glycol component, Consists of 100 mol% polytetramethylene oxide glycol component with a number average molecular weight of 1000, and its IV value is 1.05.

UV curable pressure-sensitive adhesive layer: obtained by copolymerizing 50 parts by weight of 2-ethylhexyl acrylate, 10 parts by weight of butyl acrylate, 37 parts by weight of vinyl acetate, and 3 parts by weight of 2-hydroxyethyl methacrylate Polymer of acrylic pressure-sensitive adhesive having a weight average molecular weight of 500,000: a photopolymerization type comprising 100 parts by weight, 35 parts by weight of a bifunctional urethane acrylate prepolymer having a molecular weight of 11,000 and 65 parts by weight of a pentafunctional acrylate monomer Prepolymer and / or photopolymerizable monomer (molecular weight per photopolymerizable carbon-carbon double bond is 230): 100 parts by weight, photopolymerization initiator 2,2-dimethoxy-2-phenylacetophenone: 8.3 parts by weight Parts, and polyisocyanate crosslinking agent: 6 parts by weight. The photocurable acrylic pressure-sensitive adhesive was dissolved in a 1: 1 mixed solvent of toluene and ethyl acetate, and coated and dried on an O-PET film to form a pressure-sensitive adhesive layer having a thickness of 10 μm. The UV-curable pressure-sensitive adhesive layer was formed on the base film by pressure laminating the O-PET film and the base film. The pressure-sensitive adhesive layer was aged for 7 days after production and used in the following examples.

[Example 1]
The pellets of polyether ester block copolymer-1 of the above resin are vacuum-dried and supplied to a twin-screw extruder with a screw diameter of 105 mm (TEX manufactured by Nippon Steel), vent suction: 1.5 kPa and cylinder setting Temperature: Extruded using a T-die at 245 ° C. The extruded molten film was quenched on a mirror casting drum using an air knife. Although winding was performed without interposing the process release paper, at a take-up speed exceeding 20 m / sec, the film started to wind around the casting drum and stable take-up was difficult. Taken at the take-off speed. As a result, an unstretched resin film having a thickness of 100 μm was obtained. The obtained substrate film had a surface resistance value of 8.0 × 10 ⁹ Ω, a tensile modulus of 16.0 MPa, a tensile breaking strength of 25.1 MPa, a breaking elongation of 1800%, and a total light transmittance of 96.0. %Met. An unstretched resin film obtained by casting is subjected to corona treatment on a mirror-casting surface, and further laminated with an O-PET film having an ultraviolet curable pressure-sensitive adhesive layer, thereby forming a pressure-sensitive adhesive layer on the base film. A dicing film was obtained by laminating.

A silicon wafer having a size of 200 mm and a thickness of 350 μm was attached to the dicing film, and then diced. Dicing was performed using a diamond blade (manufactured by DISCO) having a thickness of 25 μm, at a blade rotation speed of 30,000 rpm, a cutting speed of 100 mm / sec, a uncut thickness of 50 μm, and a dicing size of 5 mm square. The cut and separated chips are washed by discharging ultrapure water from a high-pressure jet nozzle, and then UV is 200 mJ / cm ^{2 in} 10 seconds using a high-pressure mercury lamp from the side of the base film opposite to the adhesive layer. Irradiation was performed to cure the adhesive. Subsequently, 40 mm expansion was performed at a speed of 3 mm / sec. The chip was not destroyed after dicing, and good antistatic performance was confirmed. In addition, no scattering and disturbance of the chips during expansion were observed, and good expanding properties were observed. Further, the adhesive had a sufficiently low adhesive strength, and no scattering or disorder of the chip at the time of pick-up and no adhesive residue on the chip were observed. The evaluation results are shown in Table 1.

[Example 2]
In Example 1, a dicing film was obtained in the same manner as in Example 1 except that a process release paper composed of an O-PET film was used and the take-off speed was 25 m / sec. The chip was not destroyed after dicing, and good antistatic performance was confirmed. In addition, no scattering and disturbance of the chips during expansion were observed, and good expanding properties were observed. Further, the adhesive had a sufficiently low adhesive strength, and no scattering or disorder of the chip at the time of pick-up and no adhesive residue on the chip were observed. The evaluation results are shown in Table 1.

[Example 3]
Instead of the pellets of polyetherester block copolymer-1 in Example 1, 90 parts by weight of pellets of polyetherester block copolymer-1 and 10 parts by weight of pellets of polyetherester block copolymer-2 A film was obtained in the same manner as in Example 1 except that the pellet mixture was uniformly mixed and was produced at a take-up speed of 25 m / sec. The base film production at such a take-off speed without using a process release paper was sufficiently stable. The obtained base film has a surface resistance value of 1.5 × 10 ¹⁰ Ω, a tensile modulus of 15.0 MPa, a tensile breaking strength of 30.5 MPa, a breaking elongation of 1800%, and a total light transmittance of 94.0. %Met. Further, an ultraviolet curable pressure-sensitive adhesive layer and a bonded dicing film were obtained in the same manner as in Example 1, and then dicing was performed in the same manner as in Example 1. As for the obtained dicing film, the same favorable result as Example 1 was obtained.

[Example 4]
Instead of the pellets of polyetherester block copolymer-1 of Example 1, 80 parts by weight of pellets of polyetherester block copolymer-1 and 20 parts by weight of pellets of polyetherester block copolymer-2 A film was obtained in the same manner as in Example 1 except that the pellet mixture was uniformly mixed and produced at a take-up speed of 30 m / sec. The base film production at such a take-off speed without using a process release paper was sufficiently stable. The obtained base film had a surface resistance of 1.6 × 10 ¹⁰ Ω, a tensile modulus of 15.0 MPa, a tensile breaking strength of 35.0 MPa, a breaking elongation of 1650%, and a total light transmittance of 83.9%. Met. Further, an ultraviolet curable pressure-sensitive adhesive layer and a bonded dicing film were obtained in the same manner as in Example 1, and then dicing was performed in the same manner as in Example 1. As for the obtained dicing film, the same favorable result as Example 1 was obtained.

[Example 5]
Instead of the pellets of polyetherester block copolymer-1 of Example 1, 90 parts by weight of pellets of polyetherester block copolymer-1 and 10 parts by weight of pellets of polyetherester block copolymer-3 A film was obtained in the same manner as in Example 1 except that the pellet mixture was uniformly mixed and was produced at a take-up speed of 25 m / sec. The base film production at such a take-off speed without using a process release paper was sufficiently stable. The obtained base film has a surface resistance of 1.2 × 10 ¹¹ Ω, a tensile modulus of 25.0 MPa, a tensile breaking strength of 40.3 MPa, a breaking elongation of 1400%, and a total light transmittance of 75.5%. Met. Further, an ultraviolet curable pressure-sensitive adhesive layer and a bonded dicing film were obtained in the same manner as in Example 1, and then dicing was performed in the same manner as in Example 1. In the obtained dicing film, disorder of the chip at the time of pick-up was recognized in a very small part, but almost good results were obtained.

[Comparative Example 1]
A film was obtained in the same manner as in Example 1, except that the pellet of polyetherester block copolymer-4 was used instead of the pellet of polyetherester block copolymer-1 in Example 1. The obtained base film had a surface resistance of 7.0 × 10 ¹⁴ Ω, a tensile modulus of 350 MPa, a tensile breaking strength of 42.0 MPa, a breaking elongation of 830%, and a total light transmittance of 63.0%. It was. Further, an ultraviolet curable pressure-sensitive adhesive layer and a bonded dicing film were obtained in the same manner as in Example 1, and then dicing was performed in the same manner as in Example 1. In the obtained dicing film, the expanding characteristics and light transmittance were insufficient, and chip disturbance during expansion and pick-up was observed. It was easy to adsorb dust.

[Comparative Example 2]
Instead of the base film of Example 1, an internal plasticized PVC film having a thickness of 100 μm was used. The surface resistance value of the PVC film was 6.0 × 10 ¹⁴ Ω, the tensile modulus was 25 MPa, the tensile strength at break was 35.0 MPa, the elongation at break was 300%, and the total light transmittance was 95.0%. A corona treatment was performed on one side of the PVC film, a comma coater was used to provide a conductive coating layer, and the dicing fill was created by laminating with an ultraviolet curable pressure-sensitive adhesive layer. The antistatic performance of the obtained dicing film was 1.0 × 10 ¹⁰ Ω in terms of surface resistance. Such a dicing film is inferior in productivity because it requires a conductive coating, and is insufficient in that more man-hours are required during disposal due to generation of chlorine gas during disposal combustion.

[Comparative Example 3]
Instead of the pellets of polyetherester block copolymer-1 of Example 1, 60 parts by weight of polypropylene and 40 parts by weight of styrene-hydrogenated isoprene block copolymer were bent at 230 ° C. with a vent type twin screw extruder ( A base film having a thickness of 100 μm was obtained in the same manner as in Example 1 except that pellets obtained by extrusion with Nippon Steel Works TEX-30XSST were used and the extrusion temperature was 230 ° C. The obtained base film has a surface resistance value of 2.0 × 10 ¹⁶ Ω, a tensile modulus of 32.0 MPa, a tensile breaking strength of 40.1 MPa, a breaking elongation of 600%, and a total light transmittance of 80.0%. Met. The mirror casting surface of the base film is subjected to corona treatment, further using a comma coater, provided with two conductive coating layers, and further bonded with an ultraviolet curable pressure-sensitive adhesive layer to obtain a dicing film, and then Example 1 Dicing was performed in the same manner as above. Such a film is insufficient in that it is inferior in productivity because a conductive coat is required.
The results are summarized in Table 1 below.

  According to the present invention described above, antistatics for semiconductor production have mechanical characteristics comparable to those of PVC films that have been considered difficult in the past, and are excellent in expanding characteristics, antistatic performance, productivity and reduction of environmental load. A functional film is provided.

Claims (9)

  An antistatic film for semiconductor production having a thickness of 10 to 500 μm formed from a polyester block copolymer, wherein (i) the polyester block copolymer comprises 30 to 70% by weight of a hard segment and 70% of its 100% by weight. (Ii) The polyester of the hard segment comprises 50 mol% or more of a terephthalic acid component or naphthalenedicarboxylic acid component based on 100 mol% of a dicarboxylic acid component, and 100 mol% of a soft segment. An antistatic film for semiconductor production comprising 70 mol% or more of a tetramethylene glycol component based on a diol component, and (iii) the soft segment comprising a poly (alkylene oxide) glycol component.   The said poly (alkylene oxide) glycol component contains 50 weight% or more of poly (ethylene oxide) glycol components of the number average molecular weight 1,500-10,000 in 100 weight% for the semiconductor manufacture of Claim 1 Antistatic film.   The polyester of the hard segment is composed of 85 to 95 mol% terephthalic acid component and 5 to 15 mol% isophthalic acid component based on 100 mol% dicarboxylic acid component. The antistatic film for semiconductor manufacture as described in the paragraph.   The said film is for semiconductor manufacture of any one of Claims 1-3 which satisfy | fills that the total light transmittance measured based on JISK7105 is the range of 99.5-60%. Antistatic film. The antistatic film for semiconductor production according to any one of claims 1 to 4, wherein the film has a surface resistivity of 10 ⁸ to 10 ¹² Ω.   The antistatic film for semiconductor production according to any one of claims 1 to 5, wherein the antistatic film for semiconductor production is a base film of a film for fixing a semiconductor wafer.   The antistatic film for semiconductor production according to claim 6, wherein the semiconductor wafer fixing film is provided with a photo-curable acrylic pressure-sensitive adhesive layer on one surface of the base film. A method for producing an antistatic film for semiconductor production,
(I) a step of preparing pellets comprising a polyester block copolymer, wherein (i) the polyester block copolymer comprises 30 to 70% by weight of a hard segment and 70 to 30% by weight of a soft segment. And (ii) the hard segment polyester comprises 50 mol% or more of a terephthalic acid component or naphthalenedicarboxylic acid component based on 100 mol% of a dicarboxylic acid component and 70 mol based on 100 mol% of a diol component. And (iii) the soft segment comprises a poly (alkylene oxide) glycol component (step-i), comprising:
(II) supplying pellets made of the polyester block copolymer to an extruder and discharging a molten resin body from a flat die (step-ii),
(III) The molten resin body is cooled with a cooling roll by nipping pressure or single-sided touch method, and has a thickness of 20 to 200 μm and a total light transmittance of 99.5 to 60% measured in accordance with JIS K7105. And a step of obtaining a solid film having a surface resistivity of 10 ⁸ to 10 ¹² Ω (step-iii), and (IV) a step of winding the film without interposing a process release paper (step- iv)
The manufacturing method of the antistatic film for semiconductor manufacture characterized by comprising.   The antistatic film for semiconductor manufacture produced with the manufacturing method of the said Claim 8.