Abstract: An abrasive disc sheet article having annular band patterns of vitrified abrasive particle agglomerate molded islands attached to a flexible disc backing is used for high-speed water-spray cooled abrading and polishing parts. Hydroplaning is prevented as excess coolant water flows around the islands instead of forming a thick water film that separates the island abrasive and the parts. Vitrification encapsulates diamond abrasive particles in glass to strongly support them against abrading forces as the expensive diamond particles are progressively worn down. Solvent-based adhesives are used to mold the islands where evaporation of the solvent results in porous islands that provide controlled rates of island eroding. A porous filler material attached to the disc backing between the island structures carries water to contact the wafer surface and cool it during abrading. Interchangeable discs having different abrasive particle sizes are quickly attached with vacuum to flat rotatable platens.

Abstract: An abrasive disc sheet article having patterns of vitrified abrasive particle agglomerate molded islands attached in annular bands on a flexible disc backing is used for high-speed water-spray cooled abrading and polishing without hydroplaning of workpieces. Hydroplaning is prevented as excess coolant water flows around the islands instead of forming a thick water film that separates the island abrasive and the workpiece. Vitrification encapsulates individual abrasive particles in glass to strongly support them to resist abrading forces and to allow them to be progressively worn down for full utilization of expensive diamond particles. Slow eroding of the agglomerates also results in very long abrade life of the abrasive discs. A porous filler material attached to the disc backing between the island structures carries water to contact the wafer surface and cool it during abrading. Interchangeable discs having different abrasive particle sizes are quickly attached with vacuum to flat rotatable platens.

Abstract: Embodiments of a high-speed rotatable workpiece abrasive polishing head are disclosed that allow flat surfaced hard material workpieces or sapphire or semiconductor wafers to be polished at high abrading speeds that can use water-mist cooled quick-change fixed abrasive island-type discs. Workpieces can be quickly attached with vacuum to a rotatable workpiece plate having a curved (e.g., spherical) bearing with an offset spherical center of rotation located at the workpiece abraded surface. Abrading contact there prevents lateral abrading friction forces from tilting workpieces and causing non-flat workpiece surfaces. The workpiece carrier plate can be rotationally driven by a floating drive shaft having a spherical spline head that contacts the workpiece carrier plate at a position close to the workpiece abraded surface to avoid tilting of the workpiece due to the shaft-applied workpiece rotation forces.

Abstract: Abrasive sheet materials, abrasive sheet materials with island distributions of abrasive particles, processes for manufacture of abrasive sheet materials with minimized abrasive content (with monolayers and as few as four layers of abrasive particles), processes for using the abrasive sheeting in high speed lapping/abrading processes, and apparatus for using the abrasive sheeting are described. The process for manufacturing the abrasive sheeting provides an economical method for providing improved quality sheeting, while also allowing for greater control over the shape and distribution of abrasive islands on the sheet than is available from present processes of manufacture.

Abstract: A movable shaft with fluid bearing low friction support for the movable shaft comprises a housing, where the housing contains a shaft, at least one fluid bearing adjacent a surface of the shaft, a source of fluid at a pressure of at least 16.7 psi into the at least one fluid bearing, at least one vent for carrying fluid from the shaft to a reduced pressure area, and at least one fluid pressure chamber at one end of the shaft. The fluid pressure chamber providing fluid pressure that provides a force along an axial direction of the shaft to move the shaft axially.