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.

IPC Classes  ?

• B24D 11/04 - Zonally-graded surfaces
• B24D 11/00 - Constructional features of flexible abrasive materialsSpecial features in the manufacture of such materials
• B24D 11/02 - Backings, e.g. foils, webs, mesh fabrics

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.

IPC Classes  ?

• B24D 11/00 - Constructional features of flexible abrasive materialsSpecial features in the manufacture of such materials
• C09K 3/14 - Anti-slip materialsAbrasives

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. The workpiece head can allow the workpieces to either float in contact with the abrasive or be held in rigid contact with the abrasive.

IPC Classes  ?

• B24B 37/04 - Lapping machines or devicesAccessories designed for working plane surfaces
• B24B 37/20 - Lapping pads for working plane surfaces

Abstract

Abrasive disk sheet articles having raised islands coated with abrasive have a flexible disk polymer backing. The top flat surfaces of the raised islands are coated with a liquid controlled-thickness slurry mixture of abrasive particles and a polymeric adhesive by use of a magnetic precision-thickness coating-control font sheet having individual open holes that are slightly smaller than the respective raised islands. The magnetic coater font sheet is placed in flat-surfaced contact with the raised island surfaces where each individual font sheet open hole is aligned with a respective island surface. A magnet placed on the non-island surface of the disk polymer backing urges the magnetic coater font sheet into conformal contact with the island surfaces. A squeegee device moved along the font sheet fills and level coats the island tops with a uniform-thickness abrasive slurry mixture. After coating, the font sheet is removed and the abrasive slurry is solidified.

IPC Classes  ?

• B24D 11/04 - Zonally-graded surfaces
• B24D 11/00 - Constructional features of flexible abrasive materialsSpecial features in the manufacture of such materials
• B24D 18/00 - Manufacture of grinding tools, e.g. wheels, not otherwise provided for