Study on Grinding Processing of Sapphire Wafer

This paper reports our recent results on the diamond grinding process of single crystallized sapphire wafers. It was found that the diamond grains were severely dislodged at the wheel/workpiece interface and the material was removed by a mixed process of both grinding and lapping. Grinding governed the wafer center while lapping dominated its fringe. By increasing the wheel speed, it was able to shift the dominant process from lapping to grinding, and achieve a better surface roughness. Nine diamond wheels varying in both concentration and bond material were tested in surface grinding of 6 inch sapphire wafer, to investigate the dynamic behavior of diamond grain in the grinding process and its resultant surface quality and productivity.