Patents by Inventor Srinivasan Ramanath
Srinivasan Ramanath 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).
-
Publication number: 20100159806Abstract: An abrasive tool including a bonded abrasive article including a bond material comprising a metal or metal alloy, abrasive grains contained within the bond material, and a reaction agent dispersed within the bond material, wherein the reaction agent chemically reacting with a surface of the workpiece during abrasion to form a reaction product.Type: ApplicationFiled: December 15, 2009Publication date: June 24, 2010Applicants: SAINT-GOBAIN ABRASIVES INC., SAINT-GOBAIN ABRASIFSInventors: Jianhui Wu, Srinivasan Ramanath
-
Publication number: 20100000159Abstract: A bond matrix for metal bonded abrasive tools includes a metal bond system, porosity and an optional filler. Tools according to embodiments of the invention exhibit long tool life, produce an acceptable quality of cut and can have self-dressing properties. The bond matrix can be used, for example, in abrasives tools configured for the electronics industry, such as 1A8 wheels for slicing ball grid arrays (BGAs) and other such slicing operations.Type: ApplicationFiled: June 30, 2009Publication date: January 7, 2010Applicants: SAINT-GOBAIN ABRASIVES, INC., SAINT-GOBAIN ABRASIFSInventors: Parul Walia, Srinivasan Ramanath, Richard W. Hall
-
Publication number: 20090151267Abstract: Abrasive tools and techniques are disclosed that can cut hard, brittle materials to relatively precise dimensions. The tools, which can include a hybrid bond of metal or metal alloy and a resin matrix together with fine abrasive grits, can be employed, for example, in mirror finish cutting applications, thereby enabling ‘1×’ or ‘single-pass’ multi-function abrasive processes. The specific selection of resin and metal or metal alloy types is such that the tool is sufficiently brittle for the purpose of manufacture and durability, but ductile enough to withstand the grinding and handling stresses (an exemplary hybrid bond includes bronze and polyimide). Numerous tool types and applications will be apparent in light of this disclosure, including abrasive products for electronic device manufacturing such as thin 1A8 blades (single blade or multi-blade configuration).Type: ApplicationFiled: December 10, 2008Publication date: June 18, 2009Inventors: Rachana D. Upadhyay, Srinivasan Ramanath, Robert F. Corcoran, JR., Thomas Puthanangady, Richard W. J. Hall, Lynn L. Harley
-
Publication number: 20090084042Abstract: Abrasive articles possessing a highly open (porous) structure and uniform abrasive grit distribution are disclosed. The abrasive articles are fabricated using a metal matrix (e.g., fine nickel, tin, bronze and abrasives). The open structure is controlled with a porosity scheme, including interconnected porosity (e.g., formed by leaching of dispersoid), closed porosity (e.g., induced by adding a hollow micro-spheres and/or sacrificial pore-forming additives), and/or intrinsic porosity (e.g., controlled via matrix component selection to provide desired densification). In some cases, manufacturing process temperatures for achieving near full density of metal bond with fillers and abrasives, are below the melting point of the filler used, although sacrificial fillers may be used as well. The resulting abrasive articles are useful in high performance cutting and grinding operations, such as back-grinding silicon, alumina titanium carbide, and silicon carbide wafers to very fine surface finish values.Type: ApplicationFiled: October 1, 2007Publication date: April 2, 2009Applicants: Saint-Gobain Abrasives, Inc., Saint-Gobain Abrasifs Technologie et Services, S.A.SInventors: Srinivasan Ramanath, Parul Walia
-
Publication number: 20090017736Abstract: A single-use grinding tool includes a wheel portion having a profiled recess (e.g., such as a U, V, or bowl shape) extending circumferentially along the wheel portion's periphery. A multi-layered bonded abrasive (e.g., 3-dimensional matrix of abrasive grains and bond material, or multiple layers of abrasive tape) is conformably coated or otherwise applied in a uniform thickness along the profiled recess. The bonded abrasive in one particular case includes a metal bond with diamonds. However, organic, resinous, vitrified, and hybrid bonds, as well as other abrasive grit types, can be used. The wheel portion is supported by an arbor portion which may be removably coupled to the wheel portion, or formed integrally with the wheel portion. The tool is useful, for example, in edge grinding a workpiece, such as sheet glass. Methods of tool use and tool manufacture are disclosed as well.Type: ApplicationFiled: July 10, 2007Publication date: January 15, 2009Applicant: Saint-Gobain Abrasives, Inc.Inventors: Robert G. Block, Srinivasan Ramanath, Daniel L. Schier
-
Publication number: 20080271384Abstract: Tools for conditioning chemical mechanical planarization (CMP) pads comprise a substrate with abrasive particles coupled to at least one surface. The tools can have various particle and bond configurations. For instance, abrasive particles may be bonded (e.g., brazed or other metal bond technique) to one side, or to front and back sides. Alternatively, abrasive particles are bonded to a front side, and filler particles coupled to a back side. The abrasive particles can form a pattern (e.g., hexagonal) and have particle sizes that are sufficiently small to penetrate pores of a CMP pad during conditioning, leading to fewer defects on wafers polished with the conditioned CMP pad. Grain bonding can be accomplished using brazing films, although other metal bonds may be used as well. Also, balanced bond material (e.g., braze on both sides) allows for low out-of-flatness value.Type: ApplicationFiled: September 19, 2007Publication date: November 6, 2008Applicant: SAINT-GOBAIN CERAMICS & PLASTICS, INC.Inventors: Thomas Puthanangady, Taewook Hwang, Srinivasan Ramanath, Eric M. Schultz, J. Gary Baldoni, Sergej-Tomislav Buljan, Charles Dinh-Ngoc
-
Publication number: 20070037501Abstract: An abrasive tool, suitable for cutting, slotting, grinding and polishing hard materials, such as ceramics, metals, and composites thereof, and methods for making same. The tool includes a plurality of pores positioned in an abrasive region adjacent an outer circumference of the disk. The pores have any predetermined shape, size and position relative to one another.Type: ApplicationFiled: August 11, 2005Publication date: February 15, 2007Applicant: Saint-Gobain Abrasives, Inc.Inventors: Sergej-Tomislav Buljan, Srinivasan Ramanath, Donald Brodeur, Robert Corcoran
-
Patent number: 6755729Abstract: An abrasive article including from about 40 to about 80 volume percent interconnected porosity, the article being useful as a segment for a segmented grinding wheel, and a method for fabricating the same. The method includes blending a mixture of abrasive grain, bond material and dispersoid particles, the mixture including from about 40 to about 80 volume percent dispersoid particles. In one embodiment the mixture includes from about 50 to about 80 volume percent dispersoid particles. In another embodiment the mixture includes an organic bond material and from about 40 to about 80 volume percent dispersoid particles. The powder mixture is then pressed into an abrasive laden composite and thermally processed. After cooling the composite is immersed into a solvent, which dissolves substantially all of the dispersoid particles, leaving a highly porous, bonded abrasive article.Type: GrantFiled: June 18, 2003Date of Patent: June 29, 2004Assignee: Saint-Cobain Abrasives Technology CompanyInventors: Srinivasan Ramanath, Sergej-Tomislav Buljan, Jason R. Wilson, Jeri Ann S. Ikeda
-
Patent number: 6685755Abstract: An abrasive article including from about 40 to about 80 volume percent interconnected porosity, the article being useful as a segment for a segmented grinding wheel, and a method for fabricating the same. The method includes blending a mixture of abrasive grain, bond material and dispersoid particles, the mixture including from about 40 to about 80 volume percent dispersoid particles. In one embodiment the mixture includes from about 50 to about 80 volume percent dispersoid particles. In another embodiment the mixture includes an organic bond material and from about 40 to about 80 volume percent dispersoid particles. The powder mixture is then pressed into an abrasive laden composite and thermally processed. After cooling the composite is immersed into a solvent, which dissolves substantially all of the dispersoid particles, leaving a highly porous, bonded abrasive article.Type: GrantFiled: November 21, 2001Date of Patent: February 3, 2004Assignee: Saint-Gobain Abrasives Technology CompanyInventors: Srinivasan Ramanath, Sergej-Tomislav Buljan, Jason R. Wilson, Jeri Ann S. Ikeda
-
Publication number: 20030232586Abstract: An abrasive article including from about 40 to about 80 volume percent interconnected porosity, the article being useful as a segment for a segmented grinding wheel, and a method for fabricating the same. The method includes blending a mixture of abrasive grain, bond material and dispersoid particles, the mixture including from about 40 to about 80 volume percent dispersoid particles. In one embodiment the mixture includes from about 50 to about 80 volume percent dispersoid particles. In another embodiment the mixture includes an organic bond material and from about 40 to about 80 volume percent dispersoid particles. The powder mixture is then pressed into an abrasive laden composite and thermally processed. After cooling the composite is immersed into a solvent, which dissolves substantially all of the dispersoid particles, leaving a highly porous, bonded abrasive article.Type: ApplicationFiled: June 18, 2003Publication date: December 18, 2003Inventors: Srinivasan Ramanath, Sergej-Tomislav Buljan, Jason R. Wilson, Jeri Ann S. Ikeda
-
Publication number: 20030097800Abstract: An abrasive article including from about 40 to about 80 volume percent interconnected porosity, the article being useful as a segment for a segmented grinding wheel, and a method for fabricating the same. The method includes blending a mixture of abrasive grain, bond material and dispersoid particles, the mixture including from about 40 to about 80 volume percent dispersoid particles. In one embodiment the mixture includes from about 50 to about 80 volume percent dispersoid particles. In another embodiment the mixture includes an organic bond material and from about 40 to about 80 volume percent dispersoid particles. The powder mixture is then pressed into an abrasive laden composite and thermally processed. After cooling the composite is immersed into a solvent, which dissolves substantially all of the dispersoid particles, leaving a highly porous, bonded abrasive article.Type: ApplicationFiled: November 21, 2001Publication date: May 29, 2003Inventors: Srinivasan Ramanath, Sergej-Tomislav Buljan, Jason R. Wilson, Jeri Ann S. Ikeda
-
Patent number: 6485532Abstract: A straight, thin, monolithic abrasive wheel formed of hard and rigid abrasive grains and a sintered bond including a metal component and an active metal component exhibits superior stiffness. The metal component can be selected from among many sinterable metal compositions. The active metal is a metal capable of reacting to form a bond with the abrasive grains at sintering conditions and is present in an amount effective to integrate the grains and sintered bond into a grain-reinforced composite. A diamond abrasive, copper/tin/titanium sintered bond abrasive wheel is preferred. Such a wheel is useful for abrading operations in the electronics industry, such as cutting silicon wafers and alumina-titanium carbide pucks. The stiffness of the novel abrasive wheels is higher than conventional straight monolithic wheels and therefore improved cutting precision and less chipping can be attained without increase of wheel thickness and concomitant increased kerf loss.Type: GrantFiled: December 21, 2000Date of Patent: November 26, 2002Assignee: Saint-Gobain Abrasives Technology CompanyInventors: Richard M. Andrews, Sergej-Tomislav Buljan, Srinivasan Ramanath, Earl G. Geary
-
Publication number: 20010002356Abstract: A straight, thin, monolithic abrasive wheel formed of hard and rigid abrasive grains and a sintered bond including a metal component and an active metal component exhibits superior stiffness. The metal component can be selected from among many sinterable metal compositions. The active metal is a metal capable of reacting to form a bond with the abrasive grains at sintering conditions and is present in an amount effective to integrate the grains and sintered bond into a grain-reinforced composite. A diamond abrasive, copper/tin/titanium sintered bond abrasive wheel is preferred. Such a wheel is useful for abrading operations in the electronics industry, such as cutting silicon wafers and alumina-titanium carbide pucks. The stiffness of the novel abrasive wheels is higher than conventional straight monolithic wheels and therefore improved cutting precision and less chipping can be attained without increase of wheel thickness and concomitant increased kerf loss.Type: ApplicationFiled: December 21, 2000Publication date: May 31, 2001Inventors: Richard M. Andrews, Sergej-Tomislav Buljan, Srinivasan Ramanath, Earl G. Geary
-
Patent number: 6200208Abstract: A straight, thin, monolithic abrasive wheel formed of hard and rigid abrasive grains and a sintered bond including a metal component and an active metal component exhibits superior stiffness. The metal component can be selected from among many sinterable metal compositions. The active metal is a metal capable of reacting to form a bond with the abrasive grains at sintering conditions and is present in an amount effective to integrate the grains and sintered bond into a grain-reinforced composite. A diamond abrasive, copper/tin/titanium sintered bond abrasive wheel is preferred. Such a wheel is useful for abrading operations in the electronics industry, such as cutting silicon wafers and alumina-titanium carbide pucks. The stiffness of the novel abrasive wheels is higher than conventional straight monolithic wheels and therefore improved cutting precision and less chipping can be attained without increase of wheel thickness and concomitant increased kerf loss.Type: GrantFiled: January 7, 1999Date of Patent: March 13, 2001Assignee: Norton CompanyInventors: Richard M. Andrews, Sergej-Tomislav Buljan, Srinivasan Ramanath, Earl G. Geary
-
Patent number: 6102789Abstract: Abrasive tools suitable for precision grinding of hard brittle materials, such as ceramics and composites comprising ceramics, at peripheral wheel speeds up to 160 meters/second are provided. The abrasive tools comprise a wheel core attached to an abrasive rim of dense, metal bonded superabrasive segments by means of a thermally stable bond.Type: GrantFiled: March 27, 1998Date of Patent: August 15, 2000Assignee: Norton CompanyInventors: Srinivasan Ramanath, Shih Yee Kuo, William H. Williston, Sergej-Tomislav Buljan
-
Patent number: 6093092Abstract: Abrasive tools suitable for precision grinding of hard brittle materials, such as ceramics and composites comprising ceramics, at peripheral wheel speeds up to 160 meters/second are provided. The abrasive tools comprise a wheel core attached to an abrasive rim of dense, metal bonded superabrasive segments by means of a thermally stable bond. A preferred tool for backgrinding ceramic wafers contains graphite filler and a relatively low concentration of abrasive grain.Type: GrantFiled: December 22, 1998Date of Patent: July 25, 2000Assignee: Norton CompanyInventors: Srinivasan Ramanath, William H. Williston, Sergej-Tomislav Buljan
-
Patent number: 6056795Abstract: A straight, thin, monolithic abrasive wheel formed of hard and rigid abrasive grains and a sintered metal bond including a stiffness enhancing metal component exhibits superior stiffness. The metals can be selected from among many sinterable metal compositions. Blends of nickel and tin are preferred. The stiffness enhancing metal is a metal capable of providing substantially increased rigidity to the bond without significantly increasing bond hardness. Molybdenum, rhenium, tungsten and blends of these are favored. The sintered bond is generally formed from powders. A diamond abrasive, nickel/tin/molybdenum sintered bond abrasive wheel is preferred. Such a wheel is useful for abrading operations in the electronics industry, such as cutting silicon wafers and alumina-titanium carbide pucks.Type: GrantFiled: October 23, 1998Date of Patent: May 2, 2000Assignee: Norton CompanyInventors: Srinivasan Ramanath, Richard M. Andrews
-
Patent number: 6019668Abstract: A method for precision cylindrical grinding of hard brittle materials, such as ceramics or glass and composites comprising ceramics or glass, provides material removal rates as high as 19-380 cm.sup.3 /min/cm. The abrasive tools used in the method comprise a strong, light weight wheel core bonded to a continuous rim of abrasive segments containing superabrasive grain in a dense metal bond matrix.Type: GrantFiled: March 27, 1998Date of Patent: February 1, 2000Assignee: Norton CompanyInventors: Srinivasan Ramanath, Shih Yee Kuo, William H. Williston, Sergej-Tomislav Buljan
-
Patent number: 5834569Abstract: A composite, polymer bonded abrasive wheel is disclosed for grinding operations and especially for use with multiple station, glass beveling machines. The abrasive wheel breaks in quickly and delivers consistent performance with little or no dressing needed over the entire life of the wheel. In one aspect, the novel abrasive wheel includes a concentrically mounted, annular abrasive rim on a cup shaped hub. The rim can contain an abrasive such as diamond or cubic boron nitride which is embedded in a bonding composition that includes amino aldehyde and phenolic thermoset polymers, a plasticizer, and optionally filler. The hub includes a crosslinkable, strong and rigid, engineering polymer, preferably melamine phenolic thermoset polymer, mixed with spodumene in amount effective to make the coefficient of thermal expansion of the hub match that of the rim. The wheel can be made by simultaneously hot pressing rim and hub preforms and without an additional baking step.Type: GrantFiled: September 3, 1997Date of Patent: November 10, 1998Assignee: Norton CompanyInventors: Srinivasan Ramanath, William H. Williston, Sergej-Tomislav Buljan
-
Patent number: 5385591Abstract: The present invention is a metal bond comprising a filler with a Vickers hardness from about 300 kg/mm.sup.2 to about 800 kg/mm.sup.2 wherein the Vickers hardness of the filler is maintained above 300 kg/mm.sup.2 upon firing of the bond at a temperature above 700.degree. C. for at least about 10 minutes. The present invention further is an abrasive tool comprising a metal core; an abrasive composition comprising diamond and the above metal bond, bonded to the metal core.Type: GrantFiled: September 29, 1993Date of Patent: January 31, 1995Assignee: Norton CompanyInventors: Srinivasan Ramanath, William H. Williston