Patents by Inventor Tadahiro Kato
Tadahiro Kato has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10011046Abstract: The present invention is a fixed-abrasive-grain wire including a core wire and abrasive grains fixed on a surface of the core wire, wherein an abrasive grain density is 1200 grains/mm2 or more, where the abrasive grain density is the number of the abrasive grains per unit area on the surface of the core wire, and 2% or less of all distances between centroids of the abrasive grains are equal to or shorter than an average circle equivalent diameter of the whole abrasive grains. There can be provided a fixed-abrasive-grain wire, a wire saw, and a method for slicing a workpiece that can suppress meandering of the fixed-abrasive-grain wire during slicing a workpiece and improve TTV and warp of wafers sliced from the workpiece.Type: GrantFiled: March 18, 2015Date of Patent: July 3, 2018Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Tadahiro Kato
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Patent number: 10002753Abstract: A chamfering apparatus including chamfering part for removing notch, cleaning part for cleaning and drying wafer, and chamfered-shape measuring part for measuring chamfered shape, each of chamfering and cleaning part, and chamfered-shape measuring part including rotatable stage for holding wafer and control unit for controlling rotational positions of rotatable stage and wafer, rotatable stage having reference position serving as reference of rotational positions at beginning of rotation, wherein wafer is held wherein rotational position of wafer at beginning of rotation relative to reference position is at same rotational position on all rotatable stages, and control unit to control rotational position of wafer to be at predetermined position at beginning and end of rotation.Type: GrantFiled: October 29, 2014Date of Patent: June 19, 2018Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Tadahiro Kato
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Publication number: 20170072594Abstract: The present invention is a fixed-abrasive-grain wire including a core wire and abrasive grains fixed on a surface of the core wire, wherein an abrasive grain density is 1200 grains/mm2 or more, where the abrasive grain density is the number of the abrasive grains per unit area on the surface of the core wire, and 2% or less of all distances between centroids of the abrasive grains are equal to or shorter than an average circle equivalent diameter of the whole abrasive grains. There can be provided a fixed-abrasive-grain wire, a wire saw, and a method for slicing a workpiece that can suppress meandering of the fixed-abrasive-grain wire during slicing a workpiece and improve TTV and warp of wafers sliced from the workpiece.Type: ApplicationFiled: March 18, 2015Publication date: March 16, 2017Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Tadahiro KATO
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Publication number: 20160300708Abstract: A chamfering apparatus including chamfering part for removing notch, cleaning part for cleaning and drying wafer, and chamfered-shape measuring part for measuring chamfered shape, each of chamfering and cleaning part, and chamfered-shape measuring part including rotatable stage for holding wafer and control unit for controlling rotational positions of rotatable stage and wafer, rotatable stage having reference position serving as reference of rotational positions at beginning of rotation, wherein wafer is held wherein rotational position of wafer at beginning of rotation relative to reference position is at same rotational position on all rotatable stages, and control unit to control rotational position of wafer to be at predetermined position at beginning and end of rotation.Type: ApplicationFiled: October 29, 2014Publication date: October 13, 2016Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Tadahiro KATO
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Patent number: 9358655Abstract: [Object] An outer periphery polishing apparatus capable of polishing the edge of workpieces having different bevel angles is to be provided.Type: GrantFiled: February 14, 2013Date of Patent: June 7, 2016Assignee: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Tadahiro Kato, Akitoshi Enari, Mitsutaka Irago
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Publication number: 20150283664Abstract: [Object] An outer periphery polishing apparatus capable of polishing the edge of workpieces having different bevel angles is to be provided.Type: ApplicationFiled: February 14, 2013Publication date: October 8, 2015Inventors: Tadahiro Kato, Akitoshi Enari, Mitsutaka Irago
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Patent number: 8603897Abstract: A method for manufacturing a bonded wafer including bonding together a bond wafer and a base wafer each having a chamfered portion at an outer circumference and thinning the bond wafer, wherein the thinning of the bond wafer includes: a first step of performing surface grinding on the bond wafer such that a thickness of the bond wafer reaches a first predetermined thickness; a second step of removing an outer circumference portion of the ground bond wafer; and a third step of performing surface grinding on the bond wafer such that the thickness of the bond wafer reaches a second predetermined thickness.Type: GrantFiled: December 27, 2010Date of Patent: December 10, 2013Assignee: Shin-Etsu Handotai Co., Ltd.Inventor: Tadahiro Kato
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Patent number: 8562390Abstract: A double-disc grinding apparatus having at least: a rotatable ring-shaped holder for supporting a sheet-like wafer having a notch for indicating a crystal orientation from an outer circumference side along a radial direction, the holder having a protruding portion to be engaged with the crystal-orientation-indicating notch; and a pair of grindstones for simultaneously grinding both surfaces of the wafer supported by the holder, in which the holder is provided with at least one protruding portion separately from the protruding portion to be engaged with the crystal-orientation-indicating notch, and the both surfaces of the wafer are simultaneously ground by the pair of the grindstones while the wafer is supported and rotated with the at least one protruding portion being engaged with a wafer-supporting notch formed on the wafer.Type: GrantFiled: April 20, 2009Date of Patent: October 22, 2013Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Kenji Kobayashi, Tadahiro Kato
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Chamfering apparatus for silicon wafer, method for producing silicon wafer, and etched silicon wafer
Patent number: 8454852Abstract: The invention is directed to a chamfering apparatus for a silicon wafer to chamfer outer edge of a silicon wafer by using a chamfering grindstone, the chamfering apparatus including at least: a holder holding and rotating a silicon wafer; a chamfering grindstone chamfering the outer edge of the silicon wafer held by the holder; and a control apparatus for controlling a chamfered shape by controlling a relative position of the outer edge of the silicon wafer and the chamfering grindstone by numerical control, wherein the control apparatus controls and changes the relative position of the outer edge of the silicon wafer and the chamfering grindstone at the time of chamfering depending on the circumferential position of the silicon wafer held by the holder, a production method, and an etched silicon wafer.Type: GrantFiled: January 17, 2008Date of Patent: June 4, 2013Assignee: Shin-Etsu Handotai Co., Ltd.Inventor: Tadahiro Kato -
Publication number: 20120289025Abstract: A method for manufacturing a bonded wafer including bonding together a bond wafer and a base wafer each having a chamfered portion at an outer circumference and thinning the bond wafer, wherein the thinning of the bond wafer includes: a first step of performing surface grinding on the bond wafer such that a thickness of the bond wafer reaches a first predetermined thickness; a second step of removing an outer circumference portion of the ground bond wafer; and a third step of performing surface grinding on the bond wafer such that the thickness of the bond wafer reaches a second predetermined thickness.Type: ApplicationFiled: December 27, 2010Publication date: November 15, 2012Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Tadahiro Kato
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Patent number: 8231430Abstract: The present invention is a wafer production method at least comprising a chamfering step of chamfering a wafer sliced from an ingot using a grindstone for chamfering, and a step of obtaining a product wafer thinner than the chamfered wafer by performing at least one or more than one of the following processes on the chamfered wafer: flattening, etching, and polishing, the method at least comprising a correction step of chamfering a dummy wafer equivalent in thickness to the product wafer, measuring the chamfered dummy wafer for its chamfered shape, and correcting the shape of the grindstone for chamfering based on the measured chamfered shape of the dummy wafer, at least before the chamfering step, thereby chamfering the wafer sliced from the ingot using the grindstone for chamfering having its shape corrected. Thus, it is possible to provide a wafer production method allowing a product wafer with a desired chamfered shape to be obtained in a short period of time.Type: GrantFiled: May 11, 2007Date of Patent: July 31, 2012Assignee: Shin-Etsu Handotai Co., Ltd.Inventor: Tadahiro Kato
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Publication number: 20120100785Abstract: In a conventional wafer chamfering process, the chamfered shape (cross-sectional shape) of the wafer circumference is uniform. However, in the chamfering step in wafer manufacture, the uniform chamfered shape varies with respective circumferential positions. Therefore, a wafer chamfering method that takes into account deformation in the chamfering step in the wafer manufacture is to be provided. The wafer chamfering method is for chamfering a wafer by bringing a grooveless grindstone into contact with the edge (circumferential end) of a wafer. By this wafer chamfering method, a movement trajectory formed by moving the wafer and the grindstone in a relative manner in the Z-axis and Y-axis directions and forming the same cross-sectional shape on the entire wafer circumference is set as a reference.Type: ApplicationFiled: March 30, 2010Publication date: April 26, 2012Applicants: SHIN-ETSU HANDOTAI CO., LTD., DAITO ELECTRON CO., LTD.Inventors: Yukio Ishimasa, Ichiro Katayama, Tadahiro Kato, Kuniaki Oonishi
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Patent number: 8037878Abstract: The present invention is a wire saw in which a wire for slicing is wound around a plurality of rollers to form a wire row; the wire for slicing is driven axially in a reciprocating direction; a workpiece is sliced simultaneously at a plurality of points arranged in an axial direction by feeding the workpiece against the wire row with the workpiece cut into while a slurry is supplied to the wire for slicing; the wire saw controlling in such a manner that the workpiece is extracted while the wire is caused to travel at a speed of 2 m/min or less at the time of extracting the workpiece from the wire row after slicing the workpiece. As a result, there is provided a wire saw in which the workpiece sliced with the wire row of the wire saw can be extracted from the wire row with a simple structure without a negative influence on its slicing surface.Type: GrantFiled: November 17, 2008Date of Patent: October 18, 2011Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Koji Kitagawa, Tadahiro Kato, Yukio Itoi, Tomiichi Sudou
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Patent number: 8029339Abstract: A workpiece double-disc grinding apparatus including a holder that supports a thin-plate-like workpiece from an outer periphery along a radial direction and is rotatable; a pair of static pressure support members that support the holder from both sides along an axial direction of the rotation thereof in a contactless manner based on a static fluid pressure; and a pair of grinding stones that simultaneously grind both surfaces of a workpiece supported by the holder, in which an interval between the holder and the static pressure support member is not greater than 50 ?m, and the static pressure of the fluid that is not lower than 0.3 MPa. As a result, the workpiece double-disc grinding apparatus and a workpiece double-disc grinding method can stabilize a position of the holder, which can be a cause that degrades a nanotopography of the workpiece in the double-disc grinding for the workpiece.Type: GrantFiled: January 23, 2009Date of Patent: October 4, 2011Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Tadahiro Kato, Kenji Kobayashi
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Patent number: 7997262Abstract: The present invention provides a method of improving nanotopography of a surface of a wafer sliced from an ingot by using a wire saw apparatus, including improving straightness of feed of a work feed table which is included in the wire saw apparatus and used for feeding the ingot to a wire row formed by winding a wire around a plurality of rollers, and also provides a wire saw apparatus for slicing an ingot to manufacture a wafer, including: a wire row formed by winding a wire around a plurality of rollers; a work feed table for holding and feeding the ingot to the wire row; and a linear-motion guide for linearly guiding the work feed table, wherein a component having a wavelength of 20 to 200 mm in straightness of feed of the work feed table satisfies a PV value ?1.0 ?m. As a result, there are provided the method of eliminating slice waviness having periodicity to improve the nanotopography of the surface of the wafer and the wire saw apparatus.Type: GrantFiled: August 9, 2006Date of Patent: August 16, 2011Assignee: Shin-Etsu Handotai Co., Ltd.Inventors: Hiroshi Oishi, Tadahiro Kato
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Publication number: 20110053470Abstract: A workpiece double-disc grinding apparatus including a holder that supports a thin-plate-like workpiece from an outer periphery along a radial direction and is rotatable; a pair of static pressure support members that support the holder from both sides along an axial direction of the rotation thereof in a contactless manner based on a static fluid pressure; and a pair of grinding stones that simultaneously grind both surfaces of a workpiece supported by the holder, in which an interval between the holder and the static pressure support member is not greater than 50 ?m, and the static pressure of the fluid that is not lower than 0.3 MPa. As a result, the workpiece double-disc grinding apparatus and a workpiece double-disc grinding method can stabilize a position of the holder, which can be a cause that degrades a nanotopography of the workpiece in the double-disc grinding for the workpiece.Type: ApplicationFiled: January 23, 2009Publication date: March 3, 2011Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Tadahiro Kato, Kenji Kobayashi
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Publication number: 20110039476Abstract: A double-disc grinding apparatus having at least: a rotatable ring-shaped holder for supporting a sheet-like wafer having a notch for indicating a crystal orientation from an outer circumference side along a radial direction, the holder having a protruding portion to be engaged with the crystal-orientation-indicating notch; and a pair of grindstones for simultaneously grinding both surfaces of the wafer supported by the holder, in which the holder is provided with at least one protruding portion separately from the protruding portion to be engaged with the crystal-orientation-indicating notch, and the both surfaces of the wafer are simultaneously ground by the pair of the grindstones while the wafer is supported and rotated with the at least one protruding portion being engaged with a wafer-supporting notch formed on the wafer.Type: ApplicationFiled: April 20, 2009Publication date: February 17, 2011Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Kenji Kobayashi, Tadahiro Kato
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Publication number: 20100252017Abstract: The present invention is a wire saw in which a wire for slicing is wound around a plurality of rollers to form a wire row; the wire for slicing is driven axially in a reciprocating direction; a workpiece is sliced simultaneously at a plurality of points arranged in an axial direction by feeding the workpiece against the wire row with the workpiece cut into while a slurry is supplied to the wire for slicing; the wire saw controlling in such a manner that the workpiece is extracted while the wire is caused to travel at a speed of 2 m/min or less at the time of extracting the workpiece from the wire row after slicing the workpiece. As a result, there is provided a wire saw in which the workpiece sliced with the wire row of the wire saw can be extracted from the wire row with a simple structure without a negative influence on its slicing surface.Type: ApplicationFiled: November 17, 2008Publication date: October 7, 2010Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Koji Kitagawa, Tadahiro Kato, Yukio Itoi, Tomiichi Sudou
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Publication number: 20100180880Abstract: The present invention provides a method of improving nanotopography of a surface of a wafer sliced from an ingot by using a wire saw apparatus, including improving straightness of feed of a work feed table which is included in the wire saw apparatus and used for feeding the ingot to a wire row formed by winding a wire around a plurality of rollers, and also provides a wire saw apparatus for slicing an ingot to manufacture a wafer, including: a wire row formed by winding a wire around a plurality of rollers; a work feed table for holding and feeding the ingot to the wire row; and a linear-motion guide for linearly guiding the work feed table, wherein a component having a wavelength of 20 to 200 mm in straightness of feed of the work feed table satisfies a PV value ?1.0 ?m. As a result, there are provided the method of eliminating slice waviness having periodicity to improve the nanotopography of the surface of the wafer and the wire saw apparatus.Type: ApplicationFiled: August 9, 2006Publication date: July 22, 2010Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventors: Hiroshi Oishi, Tadahiro Kato
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Chamfering Apparatus For Silicon Wafer, Method For Producing Silicon Wafer, And Etched Silicon Wafer
Publication number: 20090324896Abstract: The invention is directed to a chamfering apparatus for a silicon wafer to chamfer outer edge of a silicon wafer by using a chamfering grindstone, the chamfering apparatus including at least: a holder holding and rotating a silicon wafer; a chamfering grindstone chamfering the outer edge of the silicon wafer held by the holder; and a control apparatus for controlling a chamfered shape by controlling a relative position of the outer edge of the silicon wafer and the chamfering grindstone by numerical control, wherein the control apparatus controls and changes the relative position of the outer edge of the silicon wafer and the chamfering grindstone at the time of chamfering depending on the circumferential position of the silicon wafer held by the holder, a production method, and an etched silicon wafer.Type: ApplicationFiled: January 17, 2008Publication date: December 31, 2009Applicant: SHIN-ETSU HANDOTAI CO., LTD.Inventor: Tadahiro Kato