JP2007039096A - Grinding pad packaged item and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding pad packaged item not changed into yellow color state or not bulged out or not shrunk and a method for manufacturing the grinding pad. <P>SOLUTION: There is provided a grinding pad packaged item in which a grinding pad is packaged with a gas barrier film having an oxygen transmittance of 2 cc/m<SP>2</SP>day or less and water vapor transmittance of 2 g/m<SP>2</SP>day or less. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention stabilizes flattening processing of optical materials such as lenses and reflecting mirrors, silicon wafers, glass substrates for hard disks, aluminum substrates, and materials that require high surface flatness such as general metal polishing processing. Further, the present invention relates to a polishing pad packaged product in which a polishing pad that can be performed with high polishing efficiency is packed with a film, and a method for manufacturing the same.

  A typical material that requires high surface flatness is a single crystal silicon disk called a silicon wafer for manufacturing a semiconductor integrated circuit (IC, LSI). Silicon wafers have a highly accurate surface in each process of stacking and forming oxide layers and metal layers in order to form reliable semiconductor junctions of various thin films used for circuit formation in IC, LSI, and other manufacturing processes. It is required to finish flat. In such a polishing finishing process, a polishing pad is generally fixed to a rotatable support disk called a platen, and a workpiece such as a semiconductor wafer is fixed to a polishing head. A polishing operation is performed by generating a relative speed between the platen and the polishing head by both movements, and continuously supplying a polishing slurry containing abrasive grains onto the polishing pad.

  The polishing pad is usually packed in a resin bag before use in order to prevent foreign matters such as dust from adhering. However, such packed polishing pads have problems such as changes in physical properties during storage, and scratches (scratches) on the wafer surface during use.

  In order to prevent the occurrence of scratches due to changes in physical properties during storage and the reduction of the polishing rate, a method of covering the surface of the polishing layer with a material having a light transmittance of 50% or less in the entire wavelength region of 300 to 380 nm has been proposed. (Patent Document 1).

  In addition to the above problems, there was a problem that the physical properties of the surface layer differ from those of the inside due to yellowing of the polishing pad during storage. Further, when the polishing pad expands or contracts during storage, there is a problem that floating occurs when the polishing pad is fixed to the platen, and the thickness of the pad becomes non-uniform.

JP 2004-259728 A

  An object of the present invention is to provide a polishing pad package in which a polishing pad does not yellow, expand or contract during storage, and a method for manufacturing the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by a polishing pad package shown below, and have completed the present invention.

That is, the present invention relates to a polishing pad packaged product in which the polishing pad is packed with a gas barrier film having an oxygen transmission rate of ² cc / m ² · day or less and a water vapor transmission rate of 2 g / m ² · day or less.

  By packing the polishing pad with the gas barrier film having the above characteristics, it is possible to effectively prevent the polishing pad from being yellowed, expanded or contracted even when stored for a long time.

Oxygen permeability of the gas barrier film is required to be not more than 2cc ^/ m 2 · day, preferably not more than 1cc ^/ m 2 · day. When the oxygen permeability exceeds ² cc / m ² · day, the pad material is likely to be altered by reaction with oxygen, and thus yellowing of the polishing pad cannot be prevented.

Further, the water vapor transmission rate of the gas barrier film needs to be ² g / m ² · day or less, and preferably 1 g / m ² · day or less. When the water vapor transmission rate exceeds 2 g / m ² · day, the amount of water vapor enters and exits, so that the polishing pad easily expands or contracts.

  The gas barrier film preferably has an average visible light transmittance of 85% or more at a wavelength of 400 to 700 nm, more preferably 90% or more. When the average light transmittance of visible light is less than 85%, there is a tendency for troubles in confirming the storage state of the polishing pad.

  The gas barrier film preferably has a maximum light transmittance of ultraviolet light at a wavelength of 200 to 300 nm of 50% or less, more preferably 30% or less. Ultraviolet rays having a wavelength of 200 to 300 nm tend to cause decomposition of the pad material, and when the maximum light transmittance of the ultraviolet rays exceeds 50%, the yellowing of the polishing pad tends to become remarkable.

  The gas barrier film is preferably a base film coated with an inorganic material. By coating the surface of the base film with an inorganic material, it is possible to effectively block the transmission of ultraviolet rays and improve the gas barrier properties.

  When the gas barrier film is used when the polishing layer of the polishing pad is formed of a polyurethane resin foam, it can particularly effectively prevent yellowing, expansion or contraction of the polishing layer.

The present invention also includes a step of packing the polishing pad with a gas barrier film having an oxygen permeability of ² cc / m ² · day or less and a water vapor permeability of 2 g / m ² · day or less in an environment having a relative humidity of 40 to 60%. It is related with the manufacturing method of the polishing pad package containing, and the polishing pad package manufactured by this method.

  Usually, the polishing pad is stored in a clean room with a relative humidity of 40 to 60%. By packing the polishing pad with the gas barrier film under the same environment, the inside of the package is maintained at a relative humidity of 40 to 60%. And the expansion or contraction of the polishing pad can be prevented. As a result, the dimensional change of the polishing pad from after manufacture to before use can be suppressed, and the polishing pad can be fixed to the platen with high accuracy.

In the above production method, further, it is preferable to 0.3μm or more fine particles are packed under 35,000 / ^{m 3} or less environment. If the packing process is performed in an environment where the number of fine particles of 0.3 μm or more exceeds 35000 / m ³ , the amount of foreign matter adhering to the polishing pad increases, and scratches due to the foreign matter tend to occur. .

In the polishing pad package of the present invention, the polishing pad is packed with a gas barrier film having an oxygen transmission rate of ² cc / m ² · day or less and a water vapor transmission rate of 2 g / m ² · day or less.

  The gas barrier film is not particularly limited as long as it has the above characteristics, but is preferably a resin film. Examples of the resin include polyethylene, polypropylene, polyester, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polycarbonate, polyamide, polyacetal, polyimide, epoxy resin, unsaturated polyester resin, melamine resin, PVA, phenol resin, ABS resin, natural resin Examples thereof include various rubbers such as rubber, neoprene rubber, chloroprene rubber, butadiene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, ethylene propylene rubber, silicone rubber, and fluorine rubber. These may be used alone or in a blend of two or more. Among these, it is preferable to use polyethylene, polypropylene, polyester, or PVA from the viewpoints of high visible light permeability, high ultraviolet blocking properties, gas barrier properties, and the like.

  The gas barrier film is preferably a film obtained by coating an inorganic material on the surface of a base film made of the above resin. Examples of the inorganic material include metal oxides such as silica, alumina, and titanium oxide. Examples of the coating method include a sol-gel method, a vacuum deposition method, a sputtering method, and an ion coating method.

  The gas barrier film may be obtained by coating the surface of a base film made of the resin with a conductive material. By imparting conductivity to the gas barrier film, it is possible to prevent the film from being charged and to suppress the adsorption of foreign substances. As the conductive material, a conductive polymer material is preferably used, and examples thereof include polythiophene, polyaniline, and polypyrrole.

As a method for obtaining a gas barrier film having an oxygen transmission rate of ² cc / m ² · day or less and a water vapor transmission rate of 2 g / m ² · day or less, a method of forming a vacuum deposited film of alumina or silica on the surface of the substrate film, And a method of forming a binary deposited film of alumina and silica.

  The thickness of the substrate film is preferably 10 to 250 μm, more preferably 20 to 100 μm, from the viewpoints of durability, gas barrier properties, visible light transmission, ultraviolet blocking properties, flexibility, and the like.

  The thickness of the deposited film is preferably 50 to 5000 mm, more preferably 100 to 1000 mm, from the viewpoints of gas barrier properties, visible light permeability, ultraviolet blocking properties, flexibility, and the like.

  As the polishing pad to be packed, known ones can be used without any particular limitation. However, when the above-mentioned gas barrier film is used when the polishing layer of the polishing pad is formed of a polyurethane resin foam, the polishing pad can be effectively used. Yellowing, expansion or contraction can be prevented. The polishing pad may have a cushion layer that is softer than the polishing layer.

  The polyurethane resin comprises an isocyanate component, a polyol component (high molecular weight polyol component, low molecular weight polyol component), and a chain extender.

  As the isocyanate component, a known compound in the field of polyurethane can be used without particular limitation. As the isocyanate component, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, aromatic diisocyanates such as p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, ethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, etc. Aliphatic diisocyanate, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate Isocyanate, alicyclic diisocyanates such as norbornane diisocyanate. These may be used alone or in combination of two or more. Of these, it is preferable to use toluene diisocyanate and 4,4'-dicyclohexylmethane diisocyanate in combination.

  Examples of the high molecular weight polyol component include polyether polyols represented by polytetramethylene ether glycol, polyester polyols represented by polybutylene adipate, polycaprolactone polyols, and a reaction product of a polyester glycol such as polycaprolactone and an alkylene carbonate. Exemplified polyester polycarbonate polyol, polyester polycarbonate polyol obtained by reacting ethylene carbonate with polyhydric alcohol, and then reacting the obtained reaction mixture with organic dicarboxylic acid, and polycarbonate obtained by transesterification reaction between polyhydroxyl compound and aryl carbonate A polyol etc. are mentioned. These may be used alone or in combination of two or more. Of these, polytetramethylene ether glycol is preferably used.

  In addition to the high molecular weight polyol component described above as the polyol component, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1, A low molecular weight polyol component such as 4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene glycol, 1,4-bis (2-hydroxyethoxy) benzene is preferably used in combination. Low molecular weight polyamine components such as ethylenediamine, tolylenediamine, diphenylmethanediamine, and diethylenetriamine may be used. The (number average) molecular weight of the low molecular weight polyol component or the low molecular weight polyamine component is less than 500, preferably 250 or less. Of these, diethylene glycol is preferably used.

  When a polyurethane resin foam is produced by a prepolymer method, a chain extender is used for curing the prepolymer. The chain extender is an organic compound having at least two active hydrogen groups, and examples of the active hydrogen group include a hydroxyl group, a primary or secondary amino group, and a thiol group (SH). Specifically, 4,4′-methylenebis (o-chloroaniline) (MOCA), 2,6-dichloro-p-phenylenediamine, 4,4′-methylenebis (2,3-dichloroaniline), 3,5 -Bis (methylthio) -2,4-toluenediamine, 3,5-bis (methylthio) -2,6-toluenediamine, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2 , 6-diamine, trimethylene glycol-di-p-aminobenzoate, 1,2-bis (2-aminophenylthio) ethane, 4,4′-diamino-3,3′-diethyl-5,5′-dimethyl Diphenylmethane, N, N′-di-sec-butyl-4,4′-diaminodiphenylmethane, 3,3′-diethyl-4,4′-diaminodiphenylmethane, m-xyl Diamines, N, N′-di-sec-butyl-p-phenylenediamine, m-phenylenediamine, and polyamines exemplified by p-xylylenediamine, or the above-described low molecular weight polyol components and low molecular weight polyamine components Can be mentioned. These may be used alone or in combination of two or more. Among these, it is preferable to use 3,5-bis (methylthio) -2,4-toluenediamine and 3,5-bis (methylthio) -2,6-toluenediamine.

  The polyurethane resin foam can be produced by either the prepolymer method or the one-shot method. However, an isocyanate-terminated prepolymer is synthesized beforehand from an isocyanate component and a polyol component, and this is reacted with a chain extender. The polymer method is preferred because the resulting polyurethane resin has excellent physical properties.

  Examples of the method for producing a polyurethane resin foam include a method of adding hollow beads, a mechanical foaming method, and a chemical foaming method.

  The average cell diameter of the polyurethane resin foam is preferably 30 to 80 μm, more preferably 30 to 60 μm.

  The polishing surface that comes into contact with the material to be polished of the polishing pad (polishing layer) may have a concavo-convex structure for holding and updating the slurry.

  The thickness of the polishing layer is not particularly limited, but is usually about 0.8 to 4 mm, and preferably 1.0 to 2.5 mm. As a method for producing the polishing layer having the thickness, a method of making the foam block a predetermined thickness by using a band saw type or canna type slicer, a resin is poured into a mold having a cavity of a predetermined thickness and cured. Examples thereof include a method and a method using a coating technique or a sheet forming technique.

  The polishing pad may be a laminate of a polishing layer and a cushion sheet. Examples of the cushion sheet include fiber nonwoven fabrics such as polyester nonwoven fabric, nylon nonwoven fabric and acrylic nonwoven fabric, resin-impregnated nonwoven fabrics such as polyester nonwoven fabric impregnated with polyurethane, polymer resin foams such as polyurethane foam and polyethylene foam, butadiene rubber, and isoprene. Examples thereof include rubber resins such as rubber and photosensitive resins.

The method for producing a polishing pad package according to the present invention includes a step of packing the polishing pad with the gas barrier film in an environment with a relative humidity of 40 to 60%. Moreover, in the said manufacturing method, it is further preferable to package in the environment where the microparticles | fine-particles of 0.3 micrometer or more are 35000 pieces / m < ³ > or less.

  As a means for achieving the above environment, for example, a method using a clean room or a clean booth equipped with a HEPA filter can be mentioned.

  The gas barrier film is preferably bag-shaped because the polishing pad can be easily packed. Further, it is preferable to seal the polishing pad after packing it with a gas barrier film. Sealing not only can prevent foreign matter from adhering to the polishing pad, but also can prevent expansion or contraction of the polishing pad due to moisture absorption or drying. The method for sealing is not particularly limited, and examples thereof include a heat sealing method.

  Moreover, you may seal in absence of oxygen. Thereby, yellowing due to oxygen can be more effectively prevented. Examples of the method of sealing in the absence of oxygen include a method of evacuating the inside of the film and a method of replacing the inside of the film with an inert gas such as nitrogen or argon. Note that the gas barrier film alone is weak in strength and may be scratched or a hole may be formed, making it impossible to maintain a vacuum. In such a case, it may be further packed with a thicker resin film or the like.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

(Measurement of oxygen permeability)
A sample was set in a measurement chamber of an oxygen permeability measuring device (manufactured by Modern Controls, OX-TRAN10 / 50A), and oxygen was substituted for 2 days in the measurement chamber under conditions of 0% humidity and a temperature of 25 degrees. Thereafter, the oxygen permeability of the sample ^(cc / m 2 · day) was measured.

(Measurement of water vapor transmission rate)
A sample was set in a measurement chamber of a water vapor transmission rate measuring apparatus (manufactured by Modern Controls, PERMATRAN), and the measurement chamber was substituted with water vapor for 2 days under conditions of 90% humidity and a temperature of 40 degrees. Thereafter, the water vapor transmission rate (g / m ² · day) of the sample was measured.

(Measurement of light transmittance)
The light transmittance (%) of the sample in the measurement wavelength range of 200 to 700 nm was measured using a spectrophotometer (manufactured by Hitachi, Ltd., U-3210 Spectro Photometer). And the average light transmittance of visible light in wavelength 400-700nm was computed from this measured value. Further, the maximum light transmittance of ultraviolet rays at a wavelength of 200 to 300 nm was determined.

Example 1
[Production of polishing pad]
In a container, 1229 parts by weight of toluene diisocyanate (mixture of 2,4-isomer / 2,6-isomer = 80/20), 272 parts by weight of 4,4′-dicyclohexylmethane diisocyanate, polytetramethylene ether glycol 1901 having a number average molecular weight of 1018 Part by weight and 198 parts by weight of diethylene glycol were added and reacted at 70 ° C. for 4 hours to obtain an isocyanate-terminated prepolymer.
100 parts by weight of the prepolymer and 3 parts by weight of a silicon-based nonionic surfactant (SH-192, manufactured by Toray Dow Silicone Co., Ltd.) were added to the polymerization vessel, mixed, adjusted to 80 ° C. and degassed under reduced pressure. Then, it stirred vigorously for about 4 minutes so that a bubble might be taken in in a reaction system with the rotation speed of 900 rpm using the stirring blade. Etacure 300 (Albemarle, 3,5-bis (methylthio) -2,6-toluenediamine and 3,5-bis (methylthio) -2,4-toluenediamine mixed in advance with a temperature adjusted to 70 ° C. ) 21 parts by weight were added. The mixed solution was stirred for about 1 minute and then poured into a pan-shaped open mold (casting container). When the fluidity of the mixed solution disappeared, it was placed in an oven and post-cured at 100 ° C. for 16 hours to obtain a polyurethane resin foam block.
The polyurethane resin foam block heated to about 80 ° C. was sliced using a slicer (manufactured by Amitech, VGW-125) to obtain a polyurethane resin foam sheet. Next, using a buffing machine (Amitech Co., Ltd.), the surface of the sheet was buffed to a thickness of 1.27 mm to obtain a sheet with an adjusted thickness accuracy. The buffed sheet is punched out with a diameter of 61 cm, and a concentric circle having a groove width of 0.25 mm, a groove pitch of 1.50 mm, and a groove depth of 0.40 mm on the surface using a groove processing machine (manufactured by Techno). Groove processing was performed to obtain an abrasive sheet. A double-sided tape (manufactured by Sekisui Chemical Co., Ltd., double tack tape) was attached to the surface of the polishing sheet opposite to the grooved surface using a laminator. Furthermore, the surface of the corona-treated cushion sheet (manufactured by Toray Industries, Inc., polyethylene foam, Torepef, thickness 0.8 mm) was buffed and bonded to the double-sided tape using a laminator. Further, a double-sided tape was attached to the other surface of the cushion sheet using a laminator to prepare a polishing pad.

[Production of polishing pad package]
Alumina and silica are vacuum-deposited on one side of heat-sealable polyester (thickness: 50 μm) in a clean booth equipped with a HEPA filter (relative humidity 50%, 20500 particles / m ^{3 of} 0.3 μm or more). A polishing pad package was prepared by packing a polishing pad manufactured using a gas barrier film (Eco-Sial, manufactured by Toyobo Co., Ltd.) having a thickness of 150 mm. The gas barrier film used had an oxygen transmission rate of 1.8 cc / m ² · day, a water vapor transmission rate of 1.5 g / m ² · day, an average visible light transmittance of 90% at a wavelength of 400 to 700 nm, and a wavelength. The maximum light transmittance of ultraviolet rays of 200 to 300 nm was 20%. Packing was performed by heat-sealing the three sides of the gas barrier film into a bag shape, putting a polishing pad in the bag, and sucking the opening under vacuum to heat-seal the opening.

Comparative Example 1
The oxygen transmittance is 1500 cc / m ² · day, the water vapor transmittance is 50 g / m ² · day, the average light transmittance of visible light at a wavelength of 400 to 700 nm is 90%, and the maximum light transmittance of ultraviolet light at a wavelength of 200 to 300 nm. A polishing pad package was prepared in the same manner as in Example 1 except that a 50% polyethylene film was used.

The polishing pad package obtained in the examples and comparative examples was stored for one year in an indoor environment at a temperature of 25 ° C. and a relative humidity of 60%. Then, the polishing pad was taken out and evaluated whether it was yellowing or expanding.
(Evaluation of yellowing)
The color of the surface of the polishing pad before and after storage was measured with a multi-light source spectrocolorimeter (C light source, 2-degree visual field, sample area 30 mmφ), and the color difference ΔE was determined from the measured values.
(Expansion evaluation)
When the polishing pad before storage was accurately measured, the length was 50 mm and the width was 10 mm. After the storage, the length of the polishing pad was again measured accurately, and the expansion coefficient was determined by the following formula.
Expansion rate (%) = [(length after storage−length before storage) / length before storage] × 100

  Table 1 shows that the polishing pad package of the present invention hardly yellows or expands during storage.

Claims (8)

A polishing pad package in which a polishing pad is packed with a gas barrier film having an oxygen transmission rate of ² cc / m ² · day or less and a water vapor transmission rate of 2 g / m ² · day or less. The polishing pad package according to claim 1, wherein the gas barrier film has an average visible light transmittance of 85% or more at a wavelength of 400 to 700 nm. The polishing pad package according to claim 1 or 2, wherein the gas barrier film has a maximum light transmittance of 50% or less at a wavelength of 200 to 300 nm. The polishing pad package according to any one of claims 1 to 3, wherein the gas barrier film is obtained by coating the surface of a base film with an inorganic material. The polishing pad package according to any one of claims 1 to 4, wherein the polishing layer of the polishing pad is made of a polyurethane resin foam. Polishing pad package including a step of packing a polishing pad with a gas barrier film having an oxygen transmission rate of ² cc / m ² · day or less and a water vapor transmission rate of 2 g / m ² · day or less in an environment with a relative humidity of 40 to 60% Manufacturing method. Furthermore, the manufacturing method of the polishing pad package of Claim 6 which packs in the environment of 35000 piece / m < ³ > or less microparticles | fine-particles of 0.3 micrometer or more. A polishing pad package manufactured by the method according to claim 6 or 7.