Study on thermal influence of grinding process on LiTaO3

摘要

As a typical multi-functional single crystal material,Lithium tantalate (LiTaO3 or LT) exhibits its excellent electro-optical,pyroelectric and piezoelectric properties,and has now been widely applied into many applications,especially in the telecommunication field.However,the most critical issue in the process is its pyroelectric effect and piezoelectric effect which potentially leads to crack initiation during grinding.Because it is rich in plasticity,LT demands larger specific energy for material removal.As the most machining energy is eventually converted into heat,LT undergoes a rapid rise in temperature during the grinding process,thus highly risks in thermal shock.In order to clarify the thermal influence on the grinding process of LiTaO3,the effects of coolant temperature,diamond grinding wheel geometry and material of substrate are investigated in this research.The experimental results show that the increasing rate of grinding torque (or force) and surface roughness are two major factors dominating the crack initiation during grinding of LT wafers.Via a DOE (design of experiment) analysis,coolant temperature and wheel type stand out as the main factors influencing on the increasing rate and wafer surface roughness.