Process And Experimental Study On Micro Fused Silica Hemispherical Resonator

The hemispherical resonator gyroscope(HRG)is close to the inertial level and has been practical.Compared with other gyroscopes,HRG has the advantages of miniaturization and huge demand.As a core component of hemispherical resonator gyroscope,hemispherical resonators have made great progress along with the development of three-dimensional surface micromachining technology.Especially,there have been some good cases of silica resonators.In this paper,we selected high-quality fused silica and developed the hybrid process,improved glassblowing and wet etching method,to fabricate micro fused silica hemispherical resonators.This process is feasible and low cost,and is expected to realize mass production.The optimum placement and the etching rate of hemispherical shells in corrosion solution were studied.We achieved resonators with good shape and surface roughness of 5.81 ?.We also concluded how to precisely control the thickness.The rocking mode resonant frequency of the fused silica hemispherical shell is 1750 Hz,which is close to the simulation frequency.Vibration test verified feasible application of the hemispherical shell for a resonator.Silicon electrodes and nickel electrodes were designed and fabricated for millimeter-scale resonator shells.The process of deep etching silicon electrodes is simple but the pattern is damaged.We designed piles to make more solid combination between the graphics layer and the substrate in electroplating and nickel electrodes have good graphic effect.It is proposed to ablate piles and slot in negative photoresist by laser equipment to simplify the process and resolve issues from negative photoresist.The fabrication of hemispherical shells and electrodes lays the foundation for the complete process of micro fused silica hemispherical resonators.