Property Research on Nano-Micro Crystalline Diamond Coated Tools Lapping Sapphire Wafer

Diamond coating were deposited on serrated blade by hot filament chemical vapor deposition (HFCVD) method. The lapping experiments of sapphire wafer were carried out by using diamond coated tools. The diamond coatings and machined surface of the sapphire wafer were characterized by scanning electron microscopy (SEM), laser confocal microscope and Raman spectrum. The results show that the lapped sapphire chips are small irregular chips and long thread-like debris. During the lapping process, there is graphitization of diamond crystal. A low surface roughness can be obtained using a spherical grain diamond coated tool.