Abstract: A polymer inactivation method for a polycrystalline silicon manufacturing device, wherein the polymer byproducts are treated and additionally treated in a manner that controls the rate of reaction. The polymer byproducts are treated with a first inert gas under partial vacuum and a second oxygen containing gas to convert the polymer byproducts. The reaction rate can be controlled by regulating the fill pressure of reactant gas, controlling the amount of oxygen in the reactant gas, and stripping of the raw polymer with heat and or a vacuum. The solid byproduct remaining after treating the polymer, which is predominately silicon suboxides (SiOx) and silicon dioxide (SiO2), is inert and is easily removed.

Abstract: A binder composition comprising [A] an amorphous polyamide with a glass transition temperature of 140° C. or higher having a dicyclohexylmethane skeleton in the molecule and [B] a sulfonamide compound is used to provide a binder composition, a reinforcing-fiber base material and a preform respectively most suitable for RTM, which respectively exhibit excellent impact resistance and physical properties remaining stable over the variations of molding conditions and can be used for producing a fiber-reinforced composite material most suitable for members such as primary structures of aircraft.

Abstract: In some embodiments, an apparatus includes a printed circuit board and a thermal interface member. The printed circuit board is configured to be coupled to an electronic device, such as, for example, a removable (or “pluggable”) optical transceiver. A first surface of the printed circuit board includes a thermally-conductive portion, and a second surface of the printed circuit board includes a thermally-conductive portion that is coupled to the thermally-conductive portion of the first surface by a thermally-conductive via between the first surface and the second surface. The thermal interface member is coupled to the first surface of the printed circuit board such that a portion of the thermal interface member is in contact with the thermally-conductive portion of the first surface. The portion of the thermal interface member is deformable and thermally-conductive.

Abstract: The invention provides a hot melt adhesive comprising a polymer mixture of an ethylene vinyl acetate polymer with low vinyl acetate content and a functionalized metallocene catalyzed polyethylene copolymer. The hot melt adhesive has wide service temperature ranges for bonding cellulosic substrates together. The adhesive is well suited for case, tray, carton and bag sealing applications.

Abstract: A layered adhesive construct includes a backing layer and a layer of a pressure sensitive, hot melt processable adhesive composition. The adhesive composition includes a polar plasticising oil or a combination of polar plasticising oils in a content above 10% (w/w), and 10-50% (w/w) of a polar polyethylene copolymer. The polyethylene copolymer has a melt flow index below 2 g/10 min (190° C./21.1N), and the polar plasticising oil is a liquid rosin derivative, animal oils and derivatives, esters, ethers, glycols, poly propylene oxide, or alpha-butoxy-polyoxypropylene.

Abstract: A liquid-activated formulation is provided, comprising a liquid-activated colorant, a hydrochromic ionic compound, an opacifier, and a hot melt binding matrix.

Abstract: Hot melt adhesive compositions which have enhanced adhesion to difficult substrates, particularly at refrigerator/freezer temperatures or at elevated temperatures. The inventive compositions require a base polymer comprising at least one metallocene ethylene-containing polymer or at least one non-metallocene, amorphous, propylene containing polymer; a tackifier; an optional wax; and an adhesion promoting additive comprising at least one semi-crystalline polymer having a weight average molecular weight of about 30,000 daltons or less. It has been found that the adhesion promoting additive of this invention enhances the adhesion properties of a hot melt adhesive composition having a metallocene ethylene-containing base polymer or non-metallocene, amorphous, propylene containing base polymer, particularly at elevated temperatures or at low refrigerator and freezer temperatures where other conventional adhesives have been unsuccessful.

Abstract: The present invention provides a low-modulus low-stress resin which has such heat resistance that cohesive force and reliability can be retained even at high temperatures and which is applicable as various functional materials. The resin is a thermoplastic resin having a modulus of elasticity at room temperature, 25° C., of 1 GPa or lower and a modulus of elasticity at 250° C. of 1 MPa or higher, or a precursor resin thereof.

Abstract: A wax printing process, apparatus, formulation, and label. The process includes contacting a wax formulation with a surface having at least one etched region thereon, and confronting a carrier with the surface such that at least a portion of the wax transfers from the etched surface to the carrier. The apparatus includes a tray and a manifold positioned in the tray. In another aspect, the apparatus includes a gravure sleeve and a heatable mandrel disposed inside the gravure sleeve. The wax formulation includes a paraffin wax, an ester wax, a hydrocarbon resin, a microcrystalline wax, and an ethylene-vinyl acetate copolymer resin. The label includes a carrier and a wax release layer confronting a surface of the carrier. The wax release layer confronts less that the entire surface of the carrier.

Abstract: The invention provides a metal thermal interface material (TIM) with through-holes in its body and/or zigzags or wave shapes on its border, which is suitable for use at thermal interfaces of a thermal conduction path from an integrated circuit die to its associated heat sink in a packaged microelectronic component. The invention also includes a thermal module and a packaged microelectronic component including the metal thermal interface material.

Abstract: A wax printing process, apparatus, formulation, and label. The process includes contacting a wax formulation with a surface having at least one etched region thereon, and confronting a carrier with the surface such that at least a portion of the wax transfers from the etched surface to the carrier. The apparatus includes a tray and a manifold positioned in the tray. In another aspect, the apparatus includes a gravure sleeve and a heatable mandrel disposed inside the gravure sleeve. The wax formulation includes a paraffin wax, an ester wax, a hydrocarbon resin, a microcrystalline wax, and an ethylene-vinyl acetate copolymer resin. The label includes a carrier and a wax release layer confronting a surface of the carrier. The wax release layer confronts less that the entire surface of the carrier.

Abstract: A heat-sealable, peelable, coextruded composite polymeric film comprising a substrate layer of polymeric material having on a surface thereof a heat-sealable layer, wherein said heat-sealable layer comprises a copolyester of least one aromatic dicarboxylic acid, at least one aliphatic dicarboxylic acid and one or more glycol(s); the thickness of said heat-sealable layer is in the range of from about 0.3 to about 3 ?m; and the heat-sealable layer comprises one or more wax(es) is described.

Abstract: The invention provides a coated metal substrate comprising a metal substrate having an outer surface, a maskant film adhered to at least a portion of the outer surface of the metal substrate, the maskant film having a pattern of scribed lines therein, and a line sealant composition applied to the scribed lines in a maskant film. Both the maskant film and the line sealant composition are preferably radiation cured and substantially solvent-free. The invention also provides a method of protecting a metal substrate from chemical exposure by utilizing the radiation-cured maskant film and line sealant composition.

Abstract: The invention relates to a single- or multi-layered food casing, made from a thermoplastic mixture which comprises at least one aliphatic polyamide and/or copolyamide, at least one or more synthetic water-soluble polymers and at least one organic and/or inorganic filler. The skin has a water vapor permeability, as determined according to DIN 53122, in the non-oriented, monoaxially or biaxially oriented state of 50 to 1500 g/m2·d. The food casing is particularly suitable for use as an artificial sausage casing, particularly for raw sausages.

Abstract: The blow molded preform of a laminated wall structure comprises a bulging shoulder portion, which has a diameter that widens slightly in the downward direction; a bottom shell portion for molding the bottom, which has been blow molded from the corresponding portion of parison P so as to have a widened and deformed shape; an inner overhang wall portion in any position starting from the opposite side of the neck ring and ending at the upper portion of the bulging shoulder portion, with the inner wall portion having a diameter that widens in the downward direction; and/or a radially widened connecting portion of an arced shape, which has a larger diameter than the barrel portion so that the entire bottom including the bottom shell portion takes a bulging spherical shape. With this configuration, no thick area is formed in the inner overhang wall portion on the opposite side of the neck ring and/or in the pinch-off portion.

Abstract: This invention is intended to improve the heat resistance of PET bottles from a material aspect. A technical problem of this invention is to find a polyester resin which is suitable for heat and pressure resistant plastic bottles and which does not eat into productivity and is available at a low cost. The object of this invention is to provide a heat and pressure resistant plastic bottle that can be manufactured at a low cost and has pressure resistance at a high temperature and high impact strength. The means of fulfilling this object is a polyester resin comprising a major part of ethylene terephthalate units and containing at least one of minor copolymerizable components selected from a group consisting of isophthalic acid, cyclohexane dimethanol, and diethylene glycol, wherein three minor copolymerizable components have total content less than 3 mol. %.

Abstract: A polymer inactivation method for a polycrystalline silicon manufacturing device, wherein humidified gas such as water vapor and humidified nitrogen gas is supplied into a reacting furnace for manufacturing polycrystalline silicon to hydrolyze polymers adhered to an inner surface of the reacting furnace. It is preferable that a furnace wall of the reacting furnace is heated when the humidified gas is supplied.

Abstract: A heat transfer label comprising a support portion and a transfer portion for transfer of the transfer portion from the support portion to an article. The article may be untreated polyethylene, polypropylene, PET, or acrylonitrile. Heat is applied to the support portion while the transfer portion is placed into contact with the untreated polyethylene, polypropylene, or acrylonitrile article. The transfer portion comprises an adhesive layer comprising a vinyl acetate resin, a tackifying petroleum hydrocarbon resin, and a microcrystalline wax.

Abstract: There is disclosed a plurality of embodiments of composite webs of labels wherein there are labels on a pressure sensitive pressure-coated carrier web and wherein adhesive deadener coats the adhesive underlying the labels to enable the labels to be releasably adhered to the carrier web while leaving the carrier outside the peripheries of the labels non-tacky.

Abstract: We have found a novel spray-on adhesive composition made from components including a high melt index polymer and a high melt tackifier that interact to produce a composition that can form a low odor, light color, non-tacky, hot melt adhesive material that can be used in disposable article manufacture. The adhesive is thermally stable at hot melt application conditions, is low in cost, is easily applied and produces high quality disposable articles.

Abstract: A self supporting film of polyolefinic polymer(s) is described, the film having a first and a second surface where a first exposed surface of the film (A) comprises a polymeric low temperature sealable coating (LTSC) and where the second exposed surface of the film (B) comprises an olefinic polymer capable of forming a seal to the LTSC at a minimum temperature of at most about 100° C. when measured at 15 psi for 2 seconds, such that the first and second surfaces of the film have a mutual heat seal strength (A to B) of at least about 200 g/25 mm, when measured at 15 psi for 2 seconds at 120° C.; where the LTSC also comprises: (a) an anti-block additive in from an effective amount to about 15% by dry weight of the coating (b) a non-ionic anti-mist additive having an HLB value of up to about 20; and (c) optionally an anti-slip additive of a mean particle size of from about 3 to about 5 microns in an effective amount up to about 0.5% by dry weight of the coating.

Abstract: A hot melt adhesive composition that includes thermoplastic polymer, a source of zinc, at least one of aluminum trihydrate and magnesium hydroxide, and no greater than 70% by weight of a source of halogen. Articles that include a porous substrate and the hot melt adhesive composition.

Abstract: The present invention relates to a heat-setting label sheet that is a polymeric transfer sheet that can be marked and transferred by the consumer. Also encompassed by the present invention is a method of transferring the heat-setting label sheets. The heat-setting label sheets of the present invention comprise a support; an optional pressure sensitive adhesive layer; an Adhesion Layer comprising a thermoplastic polymer which melts in the range of 50–250° C., a wax which melts in the range of 50–250° C., or combinations thereof; an optional opaque layer comprising a styrene-butadiene latex, thermoplastic polymer, elastomer, and optional pigment; and a second optional opaque layer comprising vinyl acetate-ethylene copolymer, thermoplastic elastomer, elastomer and optional pigment. The heat-setting label sheet of the present invention can be imaged by an electrostatic printer or copier, ink jet printer, offset or screen printing, craft-type marking, and the like.

Abstract: The present invention relates to a process for reducing water carry-over during the production of polyolefin films or polyolefin tapes which are passed through a waterbath, where the polyolefin formulation comprises polyolefin waxes. The results are that less water is carried over and that the products have higher quality and better processing properties.

Abstract: A device for forming erasable images on a reusable medium, comprising: an erasing portion; and a writing portion; wherein the erasing portion comprises a separator for separating at least two layers of the reusable medium; and wherein the writing portion comprises automatic machine-driven pressure applicators for applying pressure but no ink to the reusable medium, thereby forming an image on the reusable medium.

Abstract: A thermally-conductive interface interposable intermediate a first heat transfer surface and an opposing second heat transfer surface to provide a thermal pathway therebetween. The interface includes a thermally-conductive compound formed into a layer which is conformable between the first and second heat transfer surface. The compound is an admixture of: (a) a liquid resin constituent; and (b) a particulate filler constituent. The liquid resin constituent may be an ethylene-propylene copolymer (EPM) or a terpolymer (EPDM) of ethylene and propylene and a diene which may be ethylidene norbornene (ENB) or dicyclopentadiene (DCPD).

Abstract: Sealant is statically applied to the edges of panels by placing a sealant on the inner surfaces of the walls of a container holding the panels. A shrink wrap sleeve is preferably applied to the panel filled containers, causing contact between the inner surface of the container and panel edges, such that the sealant is transferred to the edges of the panels. Further transfer occurs during handling of the container, due to movement of the panels in the container and contact between the sealant and panel edges.

Abstract: The invention provides a hot melt adhesive composition including a tubular reactor copolymer of ethylene and 5 to 20 mol % of comonomer units derived from an alkyl acrylate or alkyl methacrylate, wherein the copolymer has a melt index of at least 300 g/10 min. The alkyl group of the alkyl acrylate or alkyl methacrylate can be a linear or branched C1 to C12 group, particularly n-butyl. If desired, the hot melt adhesive can further include tackifiers, waxes, antioxidants and other desired additives. The hot melt adhesive composition shows improved heat resistance and favorable properties, such as has a shear adhesion fail temperature of at least 80° C., without the need to use high melting waxes. The invention further provides articles such as cartons, cases, trays, bookbindings or disposables including the hot melt adhesive compositions.

Abstract: An improved strippable glass fiber wall covering and process for its formation are provided. Initially, both sides of a glass fiber fabric are coated with a first coating applied from an aqueous dispersion of starch binder and polymeric latex binder. In a preferred embodiment a cross-linking agent and pigment also are present in the first aqueous dispersion. Following the drying of such dispersion to form a first coating on both surfaces, a second dried coating is provided on one side only that serves as a separation layer. The second coating is applied from an aqueous dispersion comprising paraffin and a rheology modifier. When applied to the wall in conventional manner, the separation layer facilitates the removal of the wall covering with ease when its time of usefulness is concluded.

Abstract: A heat-stealing film having a baze of not more than 30% and having a sealant layer made of a resin composition which comprises from 50 to 100 wt % of the total of the following components (a) to (c); (a) from 5 to 50 wt % of a block copolymer of from 50 to 95 wt % of a styrene-type hydrocarbon and from 5 to 50 wt % of a conjugated diene-type hydrocarbon, (b) from 5 to 50 wt % of an ethylene/?-olefin random copolymer, and (c) from 5 to 70 wt % of a block copolymer of from 10 to 50 wt % of a styrene-type hydrocarbon and from 50 to 90 wt % of a conjugated diene-type hydrocarbon, and (d) from 0 to 50 wt % of and impact-resistant polystyrene.

Abstract: An improved ink-jet printable heat-transfer medium comprising a base substrate having a surface coated with a hot-melt layer and an ink-receptive layer is provided. The ink-receptive layer comprises: i) non-polymeric organic particles that are a reaction product of a diamine and two molecules, each molecule having at least one carboxylic acid group and at least five carbon atoms, ii) thermoplastic polymer particles, and iii) a thermoplastic film-forming binder. The heat-transfer paper can produce printed images having improved color quality, hand, and wash-durability on a variety of fabric materials.

Abstract: The present invention relates to a heat-setting label sheet that is a polymeric transfer sheet that can be marked and transferred by the consumer. Also encompassed by the present invention is a method of transferring the heat-setting label sheets. The heat-setting label sheets of the present invention comprise a support; an optional pressure sensitive adhesive layer; an Adhesion Layer comprising a thermoplastic polymer which melts in the range of 50-250° C., a wax which melts in the range of 50-250° C., or combinations thereof; an optional opaque layer comprising a styrene-butadiene latex, thermoplastic polymer, elastomer, and optional pigment; and a second optional opaque layer comprising vinyl acetate-ethylene copolymer, thermoplastic elastomer, elastomer and optional pigment. The heat-setting label sheet of the present invention can be imaged by an electrostatic printer or copier, ink jet printer, offset or screen printing, craft-type marking, and the like.

Abstract: A thermal interface material (A) transfers heat from a heat source (12), such as a microprocessor, to a heat sink (14) for maintaining the microprocessor at a safe operating temperature. The interface material includes thermally conductive filler particles dispersed in a phase change material. The phase change material softens and flows at the operating temperature of the heat source, thereby providing good thermal contact with uneven surfaces of the heat source and heat sink, without excessive exudation and loss of the interface material. The phase change material includes a polymer component, such as an elastomer, and a melting point component, which adjusts the softening temperature of the phase change material to the operating temperature of the heat source.

Abstract: A gypsum wallboard may have a paper-covered first face with shaped regions formed along side portions near the wallboard edges, and a fibrous mat-covered second face. The fibrous mat material covering the second face extends around the wallboard edges and is overlapped by portions of the paper on the first face. The wallboard can be manufactured by depositing a gypsum slurry onto a moving web of the fibrous mat material, applying a web of the paper to the deposited gypsum slurry, and forming shaped regions in the side portions of the top surface.

Abstract: The present invention provides a coated polymer film having release properties. The film includes a self-supporting polymer film layer, and a release coating on the film layer. The release coating, which can also be applied to alternate substrates, includes a cross-linkable acrylic and a polyolefin wax. The coating can optionally include a polysiloxane in combination with one or both of the acrylic and polyolefin wax.

Abstract: A polymer blend disclosed has a coherent phase made from an aliphatic and/or semiaromatic (co)polyamide and, dispersed therein, a phase made from an olefin block copolymer grafted with intramolecular carboxylic anhydrides. The olefin block copolymer preferably comprises PP blocks and EPM blocks, and, where appropriate, also EBM blocks. A flat or tubular film is also disclosed wherein at least one layer thereof comprises the polymer blend. The film has preferably been mono- or biaxially oriented, and, where appropriate, also heat-set. A tubular film of the present invention is particularly suitable as a synthetic casing for sausages.

Abstract: The present invention relates to a flame retardant hot melt composition comprising from about 10% to about 60% by weight of the adhesive of at least one copolymer of ethylene, from about 10% to about 70% by weight of the adhesive of a flame retarding hydrated inorganic compound and from about 5% to about 35% by weight of at least one wax component.

Abstract: An image retaining card is disclosed. An image retaining card in accordance with the present invention may be utilized as an identification card, a driver's license, a passport, and the like. An image retaining card in accordance with the present invention comprises a substrate structure, a cover, and an image receptive material disposed between the substrate structure and the cover. The substrate structure comprises a substrate layer and a substrate tie layer.

Abstract: A heat-transfer label assembly. In one embodiment, the assembly comprises a carrier, the carrier comprising a paper substrate overcoated with a layer of polyethylene. The polyethylene layer is overcoated with a skim coat of wax. One or more heat-transfer labels are printed onto the skim coat and are spaced apart from one another, each label comprising a protective lacquer layer printed onto the skim coat, an ink design printed onto the protective lacquer layer, and a heat-activatable adhesive layer printed over the ink design, any exposed areas of the protective lacquer layer and a surrounding area of the skim coat. The periphery of the skim coat extends beyond the periphery of the label and is, therefore, uncovered by the label. The assembly further comprises a mask deposited over the uncovered areas of the skim coat, the mask adhering to the polyethylene layer during label-transfer and preventing transfer onto an article of the previously uncovered areas of the skim coat together with the label.

Abstract: The present invention relates to a heat sealable element, which comprises a support, a heat sealing layer comprising a thermoplastic polymer which melts in the range of 50-250° C., a wax which melts in the range of 50-250° C., or combinations thereof, and an image layer which comprises at least one polymer which is capable of selectively receiving and retaining water base colorants. The present invention further relates to a process for heat sealing an image, which comprises imaging the above-mentioned heat sealable element and heating the imaged element in order to melt the imaging layer and heat sealing layer to form substantially a single layer and encapsulating the water base colorant in the single layer.

Abstract: A thermal interface material (A) transfers heat from a heat source (12), such as a microprocessor, to a heat sink (14) for maintaining the microprocessor at a safe operating temperature. The interface material includes thermally conductive filler particles dispersed in a phase change material. The phase change material softens and flows at the operating temperature of the heat source, thereby providing good thermal contact with uneven surfaces of the heat source and heat sink, without excessive exudation and loss of the interface material. The phase change material includes a polymer component, such as an elastomer, and a melting point component, which adjusts the softening temperature of the phase change material to the operating temperature of the heat source.

Abstract: An oriented multi-layer film combination comprising: (a) a core layer of polypropylene homopolymer or copolymer; (b) a metallizable skin layer comprising a member having a wetting tension of at least 36 dynes/cm selected from the group consisting of ethylene-vinyl alcohol copolymer (EVOH), poly(vinyl alcohol) (PVOH), and polyester, adjacent one surface of said core layer, said layer being metallized to a metal thickness no greater than 5 nm; and (c) adhesion promoting amounts of an adhesive selected from the group consisting of maleic acid anhydride, modified polypropylene homopolymer or copolymer, high density polyethylene, and ethylene-vinyl acetate (EVA) copolymer, disposed between (a) and (b).

Abstract: A heat-transfer label including a non-wax, non-silicone release layer for use in decorating an article without leaving a visually discernible release residue on the decorated article. In a preferred embodiment, the label includes a transfer portion comprising a protective lacquer layer, an ink design layer over the protective lacquer layer, and a heat-activatable adhesive layer over the ink design and protective lacquer layers, the adhesive layer extending beyond the peripheries of the ink design and protective lacquer layers. The label also includes a support portion, the transfer portion being positioned over the support portion for transfer of the transfer portion from the support portion to an article upon the application of heat to the support portion while the transfer portion is placed in contact with the article. The support portion includes a carrier, the carrier preferably being a polyester film.

Abstract: Disclosed are a binary random copolymer of propylene and ethylene, and a film to be formed by sheeting the copolymer. The film has good heat-sealability, high stiffness, good anti-blocking and slipping properties, and high transparency. As having excellent heat-sealability at low-temperature, the copolymer and its film are favorably used as sealant layers of laminate films.

Abstract: The invention provides a single-layer or multi-layer packaging film or sheet having at least one layer formed of a polyamide resin composition, wherein the layer formed of the polyamide resin composition is a layer (A) formed of a polyamide resin composition comprising a copolymer nylon (c) composed of an aliphatic nylon (co)polymer component (1) and an aromatic nylon (co)polymer component (2) in a proportion of at least 5 wt. %.

Abstract: A single crystal silicon wafer having a central axis, a front side and a back side which are generally perpendicular to the central axis, a central plane between the front and back sides, a circumferential edge, and a radius extending from the central axis to the circumferential edge. The wafer comprises first and second axially symmetric regions. The first axially symmetric region extends radially inwardly from the circumferential edge, contains silicon self-interstitials as the predominant intrinsic point defect, and is substantially free of agglomerated interstitial defects. The second axially symmetric region has vacancies as the predominant intrinsic point defect, comprises a surface layer extending from the front side toward the central plane and a bulk layer extending from the surface layer to the central plane, wherein the number density of agglomerated vacancy defects present in the surface layer is less than the concentration in the bulk layer.

Abstract: A thermal interface material (A) transfers heat from a heat source (12), such as a microprocessor, to a heat sink (14) for maintaining the microprocessor at a safe operating temperature. The interface material includes thermally conductive filler particles dispersed in a phase change material. The phase change material softens and flows at the operating temperature of the heat source, thereby providing good thermal contact with uneven surfaces of the heat source and heat sink, without excessive exudation and loss of the interface material. The phase change material includes a polymer component, such as an elastomer, and a melting point component, which adjusts the softening temperature of the phase change material to the operating temperature of the heat source.

Abstract: The invention is directed to an ink-only label at least consisting of an adhesive layer, an ink-only image layer and optionally a protective layer, wherein the label, when applied to a substrate, has a water permeability coefficient, as defined herein, which is sufficient to enable fast removal of the label from the substrate with water or an aqueous alkaline solution, without destructive treatment of the said substrate.

Abstract: A thermally-conductive interface for conductively cooling a heat-generating electronic component having an associated thermal dissipation member such as a heat sink. The interface is formed as a self-supporting layer of a thermally-conductive material which is form-stable at normal room temperature in a first phase and substantially conformable in a second phase to the interface surfaces of the electronic component and thermal dissipation member. The material has a transition temperature from the first phase to the second phase which is within the operating temperature range of the electronic component.

Abstract: A silicon wafer in which both occurrences of slip dislocation and warpage are suppressed in device manufacturing processes is a silicon wafer having BMDs having an octahedral shape, wherein BMDs located at a position below the silicon wafer surface to a depth of 20 ?m and having a diagonal length of 200 nm or more are present at a concentration of ?2×109/cm3, and BMDs located at a position below a depth ?50 ?m have a diagonal length of ?10 nm to ?50 nm and a concentration of ?1×1012/cm3.