JP2013000809A - Structural member for polishing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structural member for polishing provided with an adhesive agent layer capable of maintaining a sufficient adhesive force even if immersed in a grinding liquid and fully inhibiting swelling caused by the grinding liquid.SOLUTION: The structural member for polishing includes a support body, an abrasive, and the adhesive agent layer joining these substances. The adhesive agent layer contains a polymer of monomers: including 58 to 85% by mass of a first monomer; 2 to 7% by mass of a second monomer; and 10 to 40% by mass of a third monomer. The first monomer is an alkyl (meth)acrylate having an alkyl group with carbon counts from 8 to 18 carbon atoms and provides a homopolymer with a glass-transition temperature of 0°C or less, the second monomer is a polar monomer that provides a homopolymer with a glass-transition temperature of 50°C or greater. The third monomer is an alkyl (meth)acrylate having an alkyl group with carbon counts from 4 to 18 carbon atoms or an aralkyl group having carbon counts from 7 to 18 carbon atoms and provides a homopolymer with a glass-transition temperature of 10°C or greater.

Description

  The present invention relates to a polishing structure.

  In recent years, with the miniaturization of electronic parts and the precision of optical devices, there is an increasing demand for flattening various substrates (silicon wafers, sapphire wafers, glass substrates used for hard disks, etc.) used for these. And flattening of these various board | substrates is normally performed using the grinding | polishing apparatus with which the abrasives were affixed on the surface plate (platen). At that time, a grinding fluid containing a surfactant or the like is often used to accelerate the grinding process.

  The surface plate and the polishing pad are usually attached using a double-sided adhesive tape. As this double-sided tape, for example, in Patent Document 1, “a double-sided pressure-sensitive adhesive tape for fixing an abrasive comprising a releasable pressure-sensitive adhesive layer laminated on one side of a substrate and a strong adhesive layer on the other side of the substrate, Abrasive fixing, wherein the adhesive layer includes a styrene-isoprene-styrene copolymer resin elastomer as a base elastomer, and is formed of an adhesive containing at least a petroleum resin and a terpene phenol resin as a tackifier resin. Double-sided pressure-sensitive adhesive tape is described, and Patent Document 2 describes that “a thermally active acrylic adhesive layer is provided on one side of a base material and a releasable pressure-sensitive adhesive layer is provided on the other side of the base material”. A double-sided adhesive tape for fixing abrasives characterized in that Patent Document 3 describes “a polishing product for glass polishing including a plurality of polishing composites integrally formed on a base material”. Patent Document 4 describes “abrasive article including a backing and at least one three-dimensional abrasive coating bonded to the surface of the backing”.

JP 2008-111008 A JP 2001-354926 A Special Table 2002-503559 gazette Japanese translation of PCT publication No. 2002-542057

  In the above-described polishing method, the abrasive is preferably replaced after being used until the polishing surface is reduced due to wear and polishing becomes difficult. The used abrasive is removed from the surface plate of the polishing apparatus and replaced.

  In order to avoid as much as possible that the abrasive needs to be replaced before the surface of the abrasive is completely consumed, (a) the grinding liquid penetrates the interface between the abrasive and the double-sided adhesive tape for fixing the abrasive. (B) that the adhesive layer of the double-sided adhesive tape for fixing the abrasive material comes into contact with the object to be polished and is subjected to a load caused by the sliding motion during polishing, and the peeling occurs. It is desirable to prevent it. In addition, it is thought that the said peeling arises because the contact bonding layer of the double-sided adhesive tape for abrasive | polishing agent fixation swells with polishing liquid.

  The present invention provides a polishing structure that has a pressure-sensitive adhesive layer that maintains a sufficient adhesive force even when immersed in a grinding fluid and that is sufficiently suppressed from swelling by the grinding fluid and can be used stably over a long period of time. The purpose is to provide.

  In one embodiment, the present invention is a polishing structure comprising a support, an abrasive, and an adhesive layer that joins the support, and the adhesive layer contains 58 to 85 mass of the first monomer. %, A polymer of a monomer containing 2 to 7% by weight of the second monomer and 10 to 40% by weight of the third monomer, the first monomer giving a homopolymer having a glass transition temperature of 0 ° C. or less A (meth) acrylic acid ester having an alkyl group having 8 to 18 carbon atoms, and the second monomer is a polar monomer that gives a homopolymer having a glass transition temperature of 50 ° C. or higher, and the third monomer Relates to a polishing structure, which is a (meth) acrylic acid ester having an alkyl group having 4 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms, which gives a homopolymer having a glass transition temperature of 10 ° C. or higher. That.

  Since the pressure-sensitive adhesive layer in the polishing structure contains the specific polymer, sufficient adhesion is maintained even when immersed in a grinding fluid, and swelling due to the grinding fluid is sufficiently suppressed. . Therefore, according to the polishing structure, it is possible to prevent the peeling of the adhesive and the pressure-sensitive adhesive layer due to the decrease in adhesive force, and the peeling of the pressure-sensitive adhesive layer due to the swelling of the pressure-sensitive adhesive layer, Polishing work can be performed stably over a long period of time.

  In another embodiment, the glass transition temperature of the polymer can be -15 to 10 ° C. According to the pressure-sensitive adhesive layer containing such a polymer, it is possible to sufficiently suppress the extrusion to the side surface of the polishing structure due to the pressure applied during polishing. In the polishing structure, a plurality of abrasives may be bonded on the pressure-sensitive adhesive layer, and at this time, a gap may be generated between the abrasives. At this time, according to the pressure-sensitive adhesive layer containing the polymer, the extrusion of the pressure-sensitive adhesive into the gap between the abrasives is sufficiently suppressed.

  In another aspect, the abrasive may have a base material and a three-dimensional element including a plurality of abrasive grains regularly arranged on the base material and a binder thereof.

  In another aspect, the pressure-sensitive adhesive layer may have a thickness of 50 to 500 μm.

  In still another aspect, the polishing structure may further include a removable pressure-sensitive adhesive layer provided on the other surface of the support. Such a polishing structure can be easily attached to and detached from the surface plate of the polishing apparatus by the removable adhesive layer.

  According to the present invention, a polishing agent that has a pressure-sensitive adhesive layer that maintains a sufficient adhesive force even when immersed in a grinding fluid and that can sufficiently suppress swelling due to the grinding fluid and can be used stably over a long period of time. A structure is provided.

1A is a top view of a polishing structure according to a first embodiment, and FIG. 2B is a schematic cross-sectional view showing a cross section taken along a cutting line II. (A) Top view of polishing structure which concerns on 2nd embodiment, (b) It is a schematic cross section which shows the cross section along the cutting line II-II. (A) Top view of polishing structure which concerns on 3rd embodiment, (b) It is a schematic cross section which shows the cross section along the cutting line III-III. It is a schematic cross section which shows the grinding | polishing method using the structure for grinding | polishing which concerns on 2nd embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the polishing structure of the present invention is not limited to the following embodiments. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

  FIG. 1 is a schematic cross-sectional view showing a cross-section along (a) a top view and (b) a cutting line II of the polishing structure according to the first embodiment. The polishing structure 100 according to the first embodiment includes a support 10, a pressure-sensitive adhesive layer 12 provided on one surface of the support 10, and polishing bonded to the support 10 by the pressure-sensitive adhesive layer 12. The material 14 and the releasable pressure-sensitive adhesive layer 16 provided on the other surface of the support 10 are provided.

  Although it does not specifically limit as the support body 10, For example, the plastic film which consists of polyester, polyamide, polyurethane, polyethylene, a polypropylene, ethylene vinyl acetate copolymer, polyvinyl chloride, a polycarbonate, etc .; Laminated film which laminated | stacked this plastic film; Foams made mainly of polyethylene, polyurethane, synthetic rubber or the like; woven fabrics; non-woven fabrics; etc. are preferably used.

  Although the thickness of the support body 10 is not specifically limited, It can be set to 25-5000 micrometers, and can also be set to 50-2000 micrometers.

  The pressure-sensitive adhesive layer 12 is composed of 58 to 85% by mass of a first monomer (hereinafter sometimes referred to as “component (a)”), a second monomer (hereinafter sometimes referred to as “component (b)”) 2. 7% by mass and a polymer of a third monomer (hereinafter sometimes referred to as “component (c)”) and 10 to 40% by mass of a monomer (hereinafter sometimes referred to as “monomer component”) are contained. The component (a) is a (meth) acrylic acid ester having an alkyl group having 8 to 18 carbon atoms that gives a homopolymer having a glass transition temperature of 0 ° C. or lower, and the component (b) has a glass transition temperature of 50 ° C. It is a polar monomer that gives the above homopolymer, and the component (c) has an alkyl group having 4 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms that gives a homopolymer having a glass transition temperature of 10 ° C. or higher. (Meth) acrylic acid ester. Hereinafter, the components (a) to (c) will be described in detail.

  Here, the “glass transition temperature” (also referred to as Tg) of a homopolymer is a glass state through a supercooled liquid when the heated and melted polymer is cooled under certain conditions. It means the temperature when changing. Specifically, the glass transition temperature of the homopolymer is a value measured according to JIS K7121.

  The component (a) is a (meth) acrylic acid ester having an alkyl group having 8 to 18 carbon atoms, and is a monomer that gives a homopolymer having a glass transition temperature of 0 ° C. or lower.

  The component (a) provides the adhesive layer 12 with sufficient flexibility and sufficient wettability with respect to the support 10 and the abrasive 14. In addition, the component (a) imparts hydrophobicity to the pressure-sensitive adhesive layer 12, thereby sufficiently preventing the pressure-sensitive adhesive layer 12 from swelling due to the grinding fluid.

  As component (a), 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, isomyristyl (meth) acrylate, and isocetyl (meth) Examples include acrylate, 2-octyldecyl (meth) acrylate, and isostearyl acrylate. Of these, 2-ethylhexyl acrylate and isooctyl acrylate are preferable from the viewpoint of further improving the adhesiveness of the pressure-sensitive adhesive layer 12.

  Content of (a) component in the said monomer component is 58-85 mass% on the basis of the total amount of the said monomer component, Preferably it is 65-80 mass%. When the content of the component (a) is less than 58% by mass, the pressure-sensitive adhesive layer 12 is not sufficiently hydrophobic, and swelling of the pressure-sensitive adhesive layer 12 by the grinding liquid is not sufficiently prevented. Moreover, when content of (a) component exceeds 85 mass%, the adhesive force of the adhesive layer 12 may not fully be obtained.

  The component (b) is a polar monomer that gives a homopolymer having a glass transition temperature of 50 ° C. or higher. The cohesive force of the pressure-sensitive adhesive layer 12 is improved by the component (b), and excellent adhesiveness to the support 10 and the abrasive 14 is imparted to the pressure-sensitive adhesive layer 12.

  In the case of a conventional pressure-sensitive adhesive layer, an adherend having a smooth surface (for example, a polyester film), even if strong adherence is obtained by an anchor effect on an uneven adherend (for example, urethane foam) On the other hand, a grinding fluid, for example, water may enter the interface with the adherend and peel off. On the other hand, the pressure-sensitive adhesive layer 12 exhibits excellent adhesion to an adherend having a smooth surface by the component (b). Therefore, the adhesive layer 12 can bond the support 10 and the abrasive 14 for a long period of time even in the presence of a grinding fluid.

  As the component (b), for example, an ethylenically unsaturated monomer having a functional group such as a carboxyl group or a sulfo group; vinyl ester; vinyl amide; N-vinyl lactam; (meth) acrylamide; N-alkyl (meth) acrylamide, N , Substituted acrylamides such as N-dialkyl (meth) acrylamide;

  As the component (b), acrylic acid, methacrylic acid, itaconic acid, maleic acid, styrene sulfonic acid, acryloyloxyethyl phthalate, acryloyloxypropyl phthalate, maleimide, N, N-dimethyl (meth) acrylamide, N, N -Diethyl (meth) acrylamide, Nt-butyl (meth) acrylamide, N, N-isopropyl (meth) acrylamide, Nt-octyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N , N-dimethylaminopropyl (meth) acrylamide, diacetone acrylamide, (meth) acrylonitrile, N-vinylpyrrolidone; N-vinylcaptolactam and the like. Among these, a monomer containing at least one acid group is preferable because the adhesive force and cohesive force of the pressure-sensitive adhesive layer 12 are particularly excellent. Among these, (meth) acrylic acid and (meth) acryloyloxyethyl phthalate are particularly preferable. .

  Content of (b) component in the said monomer component is 2-7 mass% on the basis of the total amount of the said monomer component, Preferably it is 3-6 mass%. When the content of the component (b) is less than 2% by mass, the adhesive force of the pressure-sensitive adhesive layer 12, particularly the adhesive force to a smooth surface may not be sufficiently obtained. In addition, when the purpose is merely to increase the adhesive force, it is preferable to increase the content of the component (b). However, in the present invention, as described above, the purpose is to suppress swelling due to the grinding fluid. It is one. By setting the content of the component (b) within the above range, both excellent adhesive force and suppression of swelling by the grinding fluid can be achieved.

  (C) The component is a (meth) acrylic acid ester having an alkyl group having 4 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms, and is a monomer that gives a homopolymer having a glass transition temperature of 10 ° C. or higher. is there.

  According to the component (c), the glass transition temperature of the polymer can be controlled while maintaining hydrophobicity. Therefore, the component (c) achieves both sufficient hydrophobicity of the pressure-sensitive adhesive layer 12 and sufficient adhesive force.

  (C) Component includes linear or branched alkyl (meth) acrylate such as t-butyl (meth) acrylate, n-butyl methacrylate, isobutyl methacrylate; cyclohexyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate And alicyclic alkyl (meth) acrylates such as isobornyl (meth) acrylate;

  Content of the (c) component in the said monomer component is 10-40 mass% on the basis of the total amount of the said monomer component, Preferably it is 20-40 mass%. When the content of the component (c) is less than 10% by mass, the glass transition temperature of the polymer is not sufficiently increased, and it is difficult to obtain a sufficient adhesive force. Moreover, when it exceeds 40 mass%, the glass transition temperature of the said polymer may become high too much, and adhesion | attachment may become difficult.

  The monomer component may contain a monomer other than the components (a) to (c). For example, the monomer component may contain a crosslinkable monomer.

  The crosslinkable monomer is a monomer having a plurality of radically polymerizable reactive groups such as a (meth) acryloyl group. According to the crosslinkable monomer, since a crosslinked structure is formed in the polymer, the cohesiveness of the pressure-sensitive adhesive layer 12 is further improved.

  Examples of the crosslinkable monomer include polyfunctional (meth) acrylate monomers such as 1,2-ethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, and 1,6-hexanediol di (meth) acrylate. Is mentioned.

  The content of the crosslinkable monomer in the monomer component is preferably 0.01 to 2% by mass, and more preferably 0.02 to 1% by mass based on the total amount of the monomer component.

  Even if the monomer component contains a monomer other than the above (a monomer other than the component (a), the component (b), the component (c), and the crosslinkable monomer) as long as the properties of the pressure-sensitive adhesive layer 12 are not impaired. Good. The content of the monomer other than the above is preferably 15% by mass or less based on the total amount of the monomer components.

  Examples of monomers other than those described above include benzyl acrylate, pentamethylpiperidyl methacrylate, N, N-dimethylaminoethyl acrylate, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-methacryloxypropylmethyl. Acrylic monomers such as diethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane; vinyl monomers such as vinyl acetate, vinyl propionate, vinyl versatic acid, styrene, vinylpyridine, and vinylimidazole; Is mentioned.

  The polymer contained in the pressure-sensitive adhesive layer 12 can be formed by polymerizing the monomer component in the presence of a polymerization initiator. The polymerization method of the monomer component is not particularly limited, and may be polymerized according to a normal radical polymerization method, for example, solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization or the like.

  Polymerization of the monomer component can be performed by a thermal polymerization method using a thermal polymerization initiator. Here, examples of the thermal polymerization initiator include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, and di (2-ethoxyethyl). ) Organic peroxidation such as peroxydicarbonate, t-butylperoxyneodecanoate, t-butylperoxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, diacetyl peroxide 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane 1-carbonitrile), 2,2′-azobis ( 2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl- -Methoxyvaleronitrile), dimethyl 2,2'-azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (2-hydroxymethylpropio) Nitrile) and 2,2′-azobis [2- (2-imidazolin-2-yl) propane] and the like.

  Polymerization of the monomer component can also be performed by a photopolymerization method using a photopolymerization initiator. Specifically, the monomer component can be polymerized by irradiating the monomer component with actinic rays such as ultraviolet rays (UV) to obtain a polymer.

  Examples of the photopolymerization initiator include acetophenone, diethoxyacetophenone, 2- [4- (methylthio) -methyl-1-phenyl] -2-morpholinopropanone, benzoin, benzoin ethyl ether, benzylmethyl ketal, benzophenone, 2 -Ethylanthraquinone, thioxanthone, diethylthioxanthone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide (for example, “Lucirin ™ TPO”, manufactured by BASF), 2,4,6-trimethylbenzoyl diethoxyphosphine oxide (for example, , “Lucirin ™ TPO-L” (manufactured by BASF), bis (2,4,6-trimethylbenzoyl) phenylphosphine (eg, “IRGACURE ™ 819”, Ciba Ja 2-hydroxy-2-methyl-1-phenylpropan-1-one (for example, “DAROCURE ™ 1173”, manufactured by Ciba Japan), 4- (2-hydroxyethoxy) phenyl (2-hydroxy-) 2-propyl) ketone (for example, “IRGACURE ™ 2959”, manufactured by Ciba Japan), 4- (2-acryloyloxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenylketone (For example, “IRGACURE ™ 184”, manufactured by Ciba Japan), 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2- Hydroxy-2-methylpropan-1-one, 2-methyl-2-morpholino (4- Omethylphenyl) propan-1-one (eg, “IRGACURE ™ 907”, manufactured by Ciba Japan), 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone (eg, “IRGACURE”). (Trademark) 369 ”, manufactured by Ciba Japan), N, N′-octamethylenebisacridine (eg,“ ADEKA Optomer ™ N1717 ”), acryloylbenzophenone (eg,“ Daicel UCB Ebercryl ™ P36 ”), etc. Can be mentioned.

  The polymer contained in the pressure-sensitive adhesive layer 12 may be crosslinked with a crosslinking agent. As the crosslinking agent, for example, a compound capable of forming a crosslinked structure with a group of the polymer is preferable. Examples of such compounds include polyfunctional isocyanates, epoxy compounds, and aziridine compounds. The crosslinking agent is preferably added in an amount of 0.01 to 3 parts by mass, more preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the polymer.

  The pressure-sensitive adhesive layer 12 may contain other components such as a tackifier, an antioxidant, a UV absorber, and a filler in addition to the polymer.

  The content of the polymer in the pressure-sensitive adhesive layer 12 is preferably 70 to 100% by mass, and more preferably 90 to 100% by mass, based on the total amount of the pressure-sensitive adhesive layer 12.

  The thickness of the pressure-sensitive adhesive layer 12 is not particularly limited as long as it is a thickness that does not cause a problem in flatness, and may be, for example, 0.025 to 1 mm. When the thickness of the pressure-sensitive adhesive layer 12 is increased, the adhesive force to the support 10 and the abrasive 14 is increased, but when the surface to be polished of the substrate is polished, the amount of deformation of the abrasive layer 12 increases, which causes the protrusion. There is a case. On the other hand, when the thickness of the pressure-sensitive adhesive layer 12 is reduced, sufficient followability and adhesiveness are obtained between the pressure-sensitive adhesive layer 12 and the abrasive 14 when the surface of the abrasive 14 in contact with the pressure-sensitive adhesive layer 12 is uneven. It may not be possible.

  The abrasive 14 is bonded to the support 10 by the pressure-sensitive adhesive layer 12, and the object to be polished is polished on the surface (polishing surface) opposite to the surface in contact with the pressure-sensitive adhesive layer 12.

The abrasive 14 can be appropriately selected according to the object to be polished. For example, the abrasive 14 may be composed of a known abrasive made of a hard material or a soft material. Examples of the abrasive made of a hard material include a hard urethane foam sheet (for example, MH ^TM C-14A (W), Supreme ^TM RN-H manufactured by Nittah Haas). Examples of the abrasive made of a soft material include a polishing pad (SUBA ^™ 400, MH ^™ S15A) manufactured by Nitta Haas, synthetic leather suede, and velor.

  The abrasive 14 may be composed of only a polishing layer capable of polishing an object to be polished, or may have a base material and a polishing layer constituting a polishing surface provided on the base material.

  The substrate holds the polishing layer on one side and contacts the pressure-sensitive adhesive layer 12 on the other side. The material of the substrate is not particularly limited, and examples thereof include polymer film, paper, metal film, Vulcan fiber, woven fabric substrate, nonwoven fabric substrate, combinations thereof, and processed products thereof. The base material is preferably made of a flexible material from the viewpoint of followability to the object to be polished.

  The polishing layer can be composed of, for example, abrasive grains and a binder thereof.

  The binder is a matrix in which abrasive grains are dispersed, for example, phenol resin, aminoplast resin, urethane resin, epoxy resin, acrylate resin, acrylated isocyanurate resin, urea-formaldehyde resin, isocyanurate resin, acrylated urethane resin. , Acrylated epoxy resins, mixtures thereof and the like.

  The dimensions of the abrasive grains vary depending on the type of abrasive grains and the polishing application. For example, the final finish polishing preferably has a size of 0.01 to 1 μm, more preferably 0.01 to 0.5 μm, and still more preferably 0.01 to 0.1 μm. Then, Preferably it is 0.5-20 micrometers, More preferably, it is 0.5-10 micrometers.

  Examples of abrasive grains include diamond, cubic boron nitride, cerium oxide, molten aluminum oxide, heat treated aluminum oxide, sol-gel aluminum oxide, silicon carbide, chromium oxide, silica, zirconia, alumina zirconia, iron oxide, garnet, and mixtures thereof. Is mentioned. Among these, diamond, cubic boron nitride, aluminum oxide, and silicon carbide are preferable for rough polishing, and silica and aluminum oxide are preferable for finish polishing.

  The releasable pressure-sensitive adhesive layer 16 is provided on the surface of the support 10 opposite to the surface on which the pressure-sensitive adhesive layer 12 is provided, and is used for attaching the polishing structure 100 to a surface plate or the like of a polishing apparatus. Is a layer.

  The polishing structure 100 is removed from the surface plate of the polishing apparatus and replaced with a new polishing structure when polishing becomes difficult due to progress of abrasion of the abrasive 14 due to polishing. Here, so that the polishing apparatus 100 can be detached from the surface plate, the polishing structure 100 and the surface plate of the polishing apparatus are joined by the removable pressure-sensitive adhesive layer 16 having removability. Therefore, it is preferable that the releasable pressure-sensitive adhesive layer 16 can be peeled off from the surface plate of the polishing apparatus without any residue when the polishing structure 100 is replaced.

  The pressure-sensitive adhesive constituting the removable pressure-sensitive adhesive layer 16 is not particularly limited, and any of natural rubber, synthetic rubber, acrylic, and the like can be used. For example, the main component is a copolymer of (meth) acrylic acid ester and a monomer having a carboxyl group or a hydroxyl group such as (meth) acrylic acid or 2-hydroxyethyl methacrylate, and this is mixed with a tackifier resin. Furthermore, what added the isocyanate type crosslinking agent and adjusted the adhesive force low can be used.

  The removable pressure-sensitive adhesive layer 16 does not necessarily come into contact with the grinding liquid, and even if swollen with the grinding liquid, it is difficult to come into contact with the object to be polished. Therefore, the re-peelable pressure-sensitive adhesive layer 16 does not necessarily need to have the effect of suppressing the swelling caused by the grinding fluid as in the pressure-sensitive adhesive layer 12.

  The thickness of the releasable pressure-sensitive adhesive layer 16 is not particularly limited, but can be 10 to 100 μm. Moreover, in another aspect, it can also be 20-50 micrometers.

  In the polishing structure 100 according to the first embodiment, since the pressure-sensitive adhesive layer 12 contains the specific polymer, sufficient adhesive force is maintained even when immersed in a grinding liquid, and grinding is performed. Swelling by the liquid is sufficiently suppressed. Therefore, according to the polishing structure 100, peeling of the abrasive 14 and the pressure-sensitive adhesive layer 12 due to a decrease in adhesive force and peeling of the pressure-sensitive adhesive layer 12 due to swelling of the pressure-sensitive adhesive layer 12 are prevented. Therefore, the polishing operation can be performed stably over a long period of time.

  Next, a second embodiment will be described in which the abrasive has a base material and a three-dimensional element including a plurality of abrasive grains regularly arranged on the base material and a binder thereof.

  FIG. 2 is a schematic cross-sectional view showing a cross-section along (a) a top view and (b) a cutting line II-II of the polishing structure according to the second embodiment. The polishing structure 110 according to the second embodiment includes a support 20, a pressure-sensitive adhesive layer 22 provided on one surface of the support 20, and polishing bonded to the support 20 by the pressure-sensitive adhesive layer 22. A material 24 and a removable pressure-sensitive adhesive layer 26 provided on the other surface of the support 10 are provided.

  As the support 20, the pressure-sensitive adhesive layer 22, and the removable pressure-sensitive adhesive layer 26 in the polishing structure 110, the support 10, the pressure-sensitive adhesive layer 12, and the removable pressure-sensitive adhesive layer 16 in the above-described polishing structure 100, respectively. The same thing can be illustrated.

  In the polishing structure 110, the abrasive 24 includes a base material 24b and a polishing layer 24a, and a plurality of three-dimensional elements 28 are regularly formed in the polishing layer 24a. Here, as the substrate 24b and the polishing layer 24a, the same substrate and polishing layer can be exemplified. The shape and the like of the three-dimensional element 28 are not particularly limited, but preferred examples will be described below.

  The adjacent three-dimensional elements 28 are preferably separated from each other by the flat portion region 29. By separating the three-dimensional elements 28, the grinding liquid can freely flow over the entire surface of the polishing structure 110 through the grooves between the three-dimensional elements 18. By allowing the grinding fluid to flow freely, a better cutting rate can be obtained and the surface finish can be further improved.

The number of three-dimensional elements 28 can range from 0.3 to about 100 per cm ² . One of the preferable shapes of the three-dimensional element 28 is a quadrangular pyramid as shown in FIG. The height of the three-dimensional element 28 (the distance from the surface formed by the flat portion region 29 to the upper surface of the three-dimensional element 28) can be, for example, about 10 to about 15000 μm. Moreover, the area of the upper surface of the quadrangular frustum of the three-dimensional element 28 can be 1 to 400 mm ² .

  The base material 24b is joined to the adhesive layer 22 and functions to support the polishing layer. The base material 24b is preferably a flexible base material from the viewpoint of further improving the followability to the object to be polished. Further, from the viewpoint of improving the durability of the polishing structure 110, the base material 24b is preferably strong and durable.

  As a material of the base material 24b, for example, a polymer film, paper, vulcanized fiber, non-woven base material, cloth base material, or the like can be selected. The substrate 24b is preferably a polymer film. Examples of the polymer film include a polyester film, a polyimide film, a polyamide film, a polypropylene film, a polycarbonate film, and a polyurethane film, and among these, a polyester film is preferable. The polyester film has excellent properties such as strength, smoothness, heat resistance, water resistance, and oil resistance. Further, the base material 24b may be subjected to easy adhesion treatment such as undercoating of an ethylene-acrylic acid copolymer in order to further improve the adhesiveness with the polishing layer 24a.

  In the polishing structure 110 according to the second embodiment, since the pressure-sensitive adhesive layer 22 contains the specific polymer, sufficient adhesive force is maintained even when immersed in a grinding liquid, and grinding is performed. Swelling by the liquid is sufficiently suppressed. Therefore, according to the polishing structure 110, peeling of the abrasive 24 and the pressure-sensitive adhesive layer 22 due to a decrease in adhesive force and peeling of the pressure-sensitive adhesive layer 22 due to swelling of the pressure-sensitive adhesive layer 22 are prevented. Therefore, the polishing operation can be performed stably over a long period of time.

  FIG. 3 is a schematic cross-sectional view showing (a) a top view and (b) a cross section taken along the cutting line III-III of the polishing structure according to the third embodiment. The polishing structure 120 according to the third embodiment includes a support 30, a pressure-sensitive adhesive layer 32 provided on one surface of the support 30, and polishing bonded to the support 30 by the pressure-sensitive adhesive layer 32. A material 34 and a removable pressure-sensitive adhesive layer 36 provided on the other surface of the support 30.

  As the support 30, the pressure-sensitive adhesive layer 32, and the removable pressure-sensitive adhesive layer 36 in the polishing structure 120, the support 10, the pressure-sensitive adhesive layer 12, and the removable pressure-sensitive adhesive layer 16 in the above-described polishing structure 100, respectively. The same thing can be illustrated.

  In the polishing structure 120, a plurality of abrasives 34 are arranged side by side on the adhesive layer 32. Each abrasive 34 has a base material 34b and an abrasive layer 34a, and a plurality of three-dimensional elements are regularly formed in the abrasive layer 34a. Here, as the substrate 34b and the polishing layer 34a, the same substrate and polishing layer can be exemplified.

  In the polishing structure 120, the abrasive 34 is provided together with the groove 38 as shown in FIG. If such a groove 38 is present, the pressure-sensitive adhesive layer 32 may flow into the groove 38 due to pressure during polishing or the like. Here, by setting the glass transition temperature of the polymer contained in the pressure-sensitive adhesive layer 32 to −15 to 10 ° C., more preferably −10 to 10 ° C., and further preferably −5 to 5 ° C., The flow of the pressure-sensitive adhesive layer 32 to the groove 38 can be sufficiently prevented.

  In the polishing structure 120 according to the third embodiment, since the pressure-sensitive adhesive layer 32 contains the specific polymer, sufficient adhesive force is maintained even when immersed in a grinding liquid, and grinding is performed. Swelling by the liquid is sufficiently suppressed. Therefore, by improving the pressure-sensitive adhesive layer 32, in the polishing structure 120, the pressure-sensitive adhesive layer caused by peeling of the abrasive 34 and the pressure-sensitive adhesive layer 32 due to a decrease in adhesive force or swelling of the pressure-sensitive adhesive layer 32. The peeling of 32 can be prevented, and the polishing operation can be performed stably over a long period of time.

  In addition, in the polishing structure 120 according to the third embodiment, the abrasive 34 in addition to the above effect by setting the glass transition temperature of the polymer contained in the adhesive layer 32 within a specific range. It is possible to prevent the pressure-sensitive adhesive layer 32 from flowing into the groove 38 formed between the two.

  FIG. 4 is a schematic cross-sectional view showing a polishing method using the polishing structure according to the second embodiment. In FIG. 4, the polishing structure 110 including the support 20, the pressure-sensitive adhesive layer 22, the abrasive 24, and the removable pressure-sensitive adhesive layer 26 is joined to the surface plate 40 of the polishing apparatus by the removable pressure-sensitive adhesive layer 26. Has been.

  The object to be polished 50 is disposed in contact with the polishing surface (polishing layer 24a) of the polishing material 24 of the polishing structure 110, and is polished by the polishing surface (polishing layer 24a).

  At the time of polishing, it is preferable that the grinding liquid is present on the surface where the workpiece 50 and the polishing layer 24a are in contact with each other. With the grinding liquid, polishing resistance can be reduced, heat generated by polishing can be removed and cooled, and polishing scraps can be prevented from adhering to the polishing surface of the workpiece 50.

  A conventionally well-known thing can be used as a grinding fluid. The grinding fluid is usually a solution containing water as a main component, and an additive is added to the solution. Examples of additives include surfactants, lubricants, and the like. Specifically, chelate compounds, alkyl sulfonates, alkyl carboxylates, alkyl phosphates, alkylaryl sulfonates, alkylaryl carboxylates , Alkylaryl phosphate, alkyl alcohol, polyalkylene glycol, polyalkylene glycol alkyl ether, polyalkylene glycol alkyl aryl ether, polyalkylene glycol alkyl ester, alkylamine, polyalkyleneamine, alkanolamine, tetraalkylammonium salt, tetraalkyl Examples include ammonium betaine.

  The surfactant may be any of an anionic surfactant, a nonionic surfactant, and a cationic surfactant, and preferably has a high hydrophilicity. Anionic surfactants and cationic surfactants having a strongly hydrophilic group in the molecule are preferred, and those having HLB of 8 or more, particularly HLB of 10 or more (Davis HLB) are preferred. Among the nonionic surfactants, those having strong hydrophilicity HLB 8 to 20, particularly HLB 10 to 20 (HLB of Griffin) are preferable. Here, the value of HLB was obtained based on the Davis method for anionic surfactants and cationic surfactants, and based on the Griffin method for nonionic surfactants. .

  The HLB is a well-known calculated value that represents the degree of affinity of the surfactant for water and oil. For Griffin's HLB (Griffin HLB), see "Journal of the Society of Cosmetic Chemist 1 (1949): 311. Journal of the Society of Chem. For Davis's HLB (Davies HLB), see "Gas / Liquid and Liquid / Liquid Interface. Proceedings of the International Congress of Surface Activity (1957): 426-438".

  In particular, when the workpiece 50 is a semiconductor wafer or non-alkali glass, it is desirable that the grinding liquid does not contain alkali metal ions or halide ions. Therefore, in this case, as the surfactant, a nonionic surfactant, an alkanolamine salt anionic surfactant, or the like is preferable.

  The content of the additive in the grinding fluid is preferably 0.001 to 50% by mass, more preferably 0.5 to 30% by mass, and still more preferably 1.0 to 10% by mass. When the content of the surfactant is less than 0.5% by mass, the adhesion preventing effect may be insufficient depending on the type. In some cases, if it exceeds 20% by mass, the grinding fluid becomes viscous and polishing abnormality may occur.

  In the polishing structure 110, since the pressure-sensitive adhesive layer 22 contains the specific polymer, sufficient adhesion is maintained even when immersed in a grinding fluid, and swelling due to the grinding fluid is sufficiently suppressed. Is done. Therefore, when the polishing structure 110 is used, even when polishing is performed in the presence of a grinding liquid, the abrasive 24 and the pressure-sensitive adhesive layer 22 are peeled off due to a decrease in adhesive force, and the pressure-sensitive adhesive layer 22 is peeled off. Peeling of the pressure-sensitive adhesive layer 22 due to swelling is sufficiently prevented, and the polishing operation can be performed stably over a long period of time.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, although a cylindrical polishing structure is illustrated in FIGS. 1 to 3, the shape of the polishing structure of the present invention is not limited to this. For example, the polishing structure may be cylindrical or polygonal.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to an Example.

  First, the storage elastic modulus and glass transition temperature Tg (dynamic viscoelastic property) measurement method, acid value measurement method, adhesive force measurement method, immersion test method, and grinding fluid absorption rate measurement method of the pressure-sensitive adhesive sheet are described below. Show.

<Measurement of storage elastic modulus and glass transition temperature (Tg) (dynamic viscoelastic properties)>
Preparation of sample: The release film was removed from the pressure-sensitive adhesive sheets prepared in the following Production Examples 1 to 11, and about 3 mm thick sheets laminated by 16 sheets were punched with a 7.9 mmφ punching blade to obtain a cylindrical sample. .

  Measurement: The advanced viscoelastic expansion system (ARES) manufactured by Rheometric Scientific was used for the dynamic viscoelastic properties. The sample fixing jig was a 7.9 mmφ parallel plate, and the columnar sample prepared by the above method was placed between the plates to adjust the tension. The dynamic viscoelastic properties are measured in air, measured in a shear mode at a frequency of 1.0 Hz, at a temperature increase rate of 5 ° C./min at −50 to 200 ° C., and storage elastic modulus G ′ (Pa) and loss. The temperature at which tan δ (loss tangent), which is the ratio of the elastic modulus G ″, peaked was taken as the glass transition temperature.

<Measurement of adhesive strength>
About the structure for grinding | polishing obtained by the following Example and comparative example, each is cut | disconnected with a cutter to 25x150mm, and it is 5 mm / in tensile tester AG-IS (Shimadzu Corporation: Chuo-ku, Kyoto). The polycarbonate film and the polishing pad were pulled at a peeling speed of min, the maximum strength was recorded, and the peeling strength of the pressure-sensitive adhesive sheet was used.

<Immersion test>
The polishing structures obtained in the following examples and comparative examples were immersed for 7 days and 14 days in 50 ° C. grinding fluid (10% aqueous solution by weight of Sabrelube ^™ 9016 Chemical Oakite) and rinsed with pure water. The adhesive strength was measured after 30 minutes. The measurement of adhesive force was performed by the same method as described above. In addition, in order to give sufficient adhesive force, it is desirable that it is 20 N / 25 mm or more at least in the initial stage and after immersion for 14 days.

<Measurement of grinding fluid absorption rate>
The pressure-sensitive adhesive sheet obtained in the following production example was cut to 25 × 70 mm with a cutter, and one of the release films present on both sides of the pressure-sensitive adhesive sheet was peeled off, and then the weight was measured. Sabrelube ™ 9016 10% aqueous solution was immersed for 10 days at 23 ° C. Rinse with pure water, then water was blown away with compressed air, and the weight was measured after 30 minutes. In order not to contact the object to be polished or the like due to swelling, it is desired that the increase rate after immersion is preferably 10%, more preferably less than 5%. From the results shown in Table 2, it can be seen that the absorption rate of the grinding fluid varies depending on the amount of acrylic acid and the amount of crosslinkable monomer in the pressure-sensitive adhesive.

(Production Example 1: Preparation of adhesive sheet)
70 parts by mass of 2-ethylhexyl acrylate (manufactured by Nippon Shokubai Co., Ltd .: Chiyoda-ku, Tokyo), 25 parts by mass of isobornyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd .: Osaka, Osaka), acrylic acid (Toa Gosei Co., Ltd .: In a glass container, 5 parts by mass of Tokyo Minato-ku) and 0.04 parts by mass of Irgacure 651 (2,2-dimethoxy-2-phenylacetophenone, BASF Japan Ltd .: Minato-ku, Tokyo) as a photopolymerization initiator After mixing well and substituting the dissolved oxygen with nitrogen gas, the polymer was partially polymerized by irradiating with ultraviolet rays for several minutes with a low-pressure mercury lamp (Sylyania TMF20T12B: OSRAMSYLVANIA Inc., Massachusetts, USA), and a viscous liquid with a viscosity of about 2500 cP Obtained. HDDA (1,6-hexanediol diacrylate, Light Acrylate ^TM 1.6HX-A: Kyoeisha Chemical Co., Ltd .: Osaka City, Osaka) 0.06 parts by mass as an crosslinking agent in the resulting viscous liquid, additional polymerization initiator (Irgacure 651: BASF Japan Co., Ltd .: Minato-ku, Tokyo) 0.15 parts by mass was added and sufficiently stirred. This mixture is coated on a 50 μm thick polyester film (Therapeutic MIB (T): Toray Film Processing Co., Ltd .: Minato-ku, Tokyo) to a thickness of 250 μm. The adhesive sheet was obtained by irradiating 2000 mJ / cm ² with a mercury lamp.

(Production Examples 2 to 11: Production of adhesive sheet)
A pressure-sensitive adhesive sheet was obtained in the same manner as in Production Example 1 except that the blending ratio (mass ratio) of each monomer was changed as shown in Table 1.

In Table 1, “2EHA” indicates 2-ethylhexyl acrylate (AEH: manufactured by Nippon Shokubai Co., Ltd .: Minato-ku, Tokyo), “IOA” indicates isooctyl acrylate (manufactured by 3M: Minnesota, USA), “AA” represents acrylic acid, “CHA” represents cyclohexyl acrylate (Osaka Organic Chemical Industry Co., Ltd .: Osaka City, Osaka Prefecture), and “IBXA” represents isobornyl acrylate (Osaka Organic Chemical Co., Ltd .: Osaka). Osaka City), “BZA” represents benzyl acrylate (Osaka Organic Chemical Industry Co., Ltd .: Osaka City, Osaka Prefecture), “BA” represents butyl acrylate (Mitsubishi Chemical Co., Ltd .: Minato-ku, Tokyo), “HDDA” is 1,6-hexanediol diacrylate (Light Acrylate ^™ 1.6HX-A: Kyoeisha Chemical Co., Ltd .: Osaka, Osaka) “IRG651” indicates Irgacure 651 (2,2-dimethoxy-2-phenylacetophenone, BASF Japan Ltd .: Minato-ku, Tokyo).

Example 1
The pressure-sensitive adhesive sheet obtained in Production Example 1 is cut to 1200 × 120 mm with a cutter, and one of the release films present on both sides of the pressure-sensitive adhesive sheet is peeled off, and then a polycarbonate film with dimensions of 1200 mm × 1200 mm × 0.75 mm (Made by GE: Connecticut, USA). Next, the remaining release film in the transparent adhesive sheet was peeled off, and the polishing pad was cut to 1200 mm from the roll (Sumitomo 3M Trisact Tile DT4M AA1HD: 250 mm width × 50 mm roll: Sumitomo 3M Limited; Setagaya-ku, Tokyo) The rubber roller was used for pasting. Thereafter, laminating treatment was performed at 80 ° C. and 0.5 MPa with a laminator (ARCTIC AGLE 1600: Nippon GC Co., Ltd .; Nakano-ku, Tokyo) to obtain a polishing structure.

(Examples 2 to 7)
A polishing structure was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive sheets obtained in Production Examples 2 to 7 were used in place of the pressure-sensitive adhesive sheets obtained in Production Example 1.

(Comparative Examples 1-4)
A polishing structure was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive sheets obtained in Production Examples 8 to 11 were used instead of the pressure-sensitive adhesive sheets obtained in Production Example 1.

  For Examples 1 to 7 and Comparative Examples 1 to 4, the storage elastic modulus and glass transition temperature Tg (dynamic viscoelastic properties) of the pressure-sensitive adhesive sheet, the acid value, and the adhesive strength are measured by the above methods. An immersion test and measurement of the grinding fluid absorption rate were performed. The evaluation results are as shown in Table 2.

  DESCRIPTION OF SYMBOLS 10, 20, 30 ... Support body, 12, 22, 32 ... Adhesive layer, 14, 24, 34 ... Abrasive material, 16, 26, 36 ... Removable adhesive layer, 28 ... Three-dimensional element, 29 ... Flat part Area, 40 ... surface plate, 50 ... object to be polished, 100, 110, 120 ... structure for polishing.

Claims (5)

A polishing structure comprising a support, an abrasive, and a pressure-sensitive adhesive layer for joining them,
The pressure-sensitive adhesive layer contains a polymer of monomers including a first monomer 58 to 85% by mass, a second monomer 2 to 7% by mass, and a third monomer 10 to 40% by mass,
The first monomer is a (meth) acrylic acid ester having an alkyl group having 8 to 18 carbon atoms that gives a homopolymer having a glass transition temperature of 0 ° C. or lower.
The second monomer is a polar monomer that gives a homopolymer having a glass transition temperature of 50 ° C. or higher,
The third monomer is a (meth) acrylic acid ester having an alkyl group having 4 to 18 carbon atoms or an aralkyl group having 7 to 18 carbon atoms, which gives a homopolymer having a glass transition temperature of 10 ° C. or higher. Structure.   The polishing structure according to claim 1, wherein the polymer has a glass transition temperature of −15 to 10 ° C.   The polishing structure according to claim 1 or 2, wherein the abrasive has a base material and a three-dimensional element including a plurality of abrasive grains regularly arranged on the base material and a binder thereof.   The polishing structure according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive layer has a thickness of 50 to 500 µm.   The polishing structure according to any one of claims 1 to 4, further comprising a releasable pressure-sensitive adhesive layer provided on the other surface of the support.

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