Patent ID: 9427841
Filing Date: 2016-08-30
CPC Classification: B24B

Claim Text:
1. A method for simultaneously polishing both surfaces of an optical substrate comprising: providing an upper platen and a lower platen, each covered with a polishing pad material; providing at least one carrier having an aperture for holding the optical substrate between the upper platen and the lower platen and adapted to allow the polishing pad material of the upper platen and the lower platen to simultaneously contact an upper surface and a lower surface of the optical substrate, respectively; setting a first location of the aperture of the carrier such that a center of the optical substrate is offset from a center of the carrier and at least a portion of an outer perimeter of the optical substrate extends outwardly beyond at least a portion of at least one of an outer perimeter and an inner perimeter of the upper platen and the lower platen; rotating the upper platen and the lower platen; rotating the carrier; stopping the rotation of the upper platen and the lower platen; stopping the rotation of the carrier; setting a location of the aperture of the carrier to a second location wherein at least a portion of an outer perimeter of the optical substrate extends outwardly beyond at least a portion of at least one of an outer perimeter and an inner perimeter of the upper platen and the lower platen; rotating the upper platen and the lower platen; and rotating the carrier, wherein a maximum distance during rotation that the outer perimeter of the optical substrate extends beyond the at least one of the outer perimeter and the inner perimeter of the upper platen and the lower platen when the aperture is in the second location is different from a maximum distance during rotation that the outer perimeter of the optical substrate extends beyond the at least one of the outer perimeter and the inner perimeter of the upper platen and the lower platen when the aperture is in the first location.