一种高灵敏度石英微机械陀螺敏感器件

摘要

In view of the anisotropic etching characteristics of quartz crystal, a novel high-sensitivity quartz micromachined gyro with two double W-shaped cross-section driving tines was introduced. The groove side-wall’s gradient, electric field excitation efficiency and gyro sensitivity were improved by setting two deep grooves on both sides of driving tines.The piezoelectric force was computed and the structure parameters were optimized with FEA (Finite Element Analysis) method. Three kinds of gyros were successfully manufactured on a 3-inch quartz crystal wafer by chemical anisotropic etching and metal film deposition. Experiment results show that the sensitivity of the chip with two double W-shaped cross-section driving tines was improved by 60% compared to the chip with rectangle cross-section driving tines.%针对石英晶体各向异性的特点，设计了一种驱动梁为双“W”截面形状的石英音叉微机械陀螺，通过在驱动梁表面凹槽两端设置深凹槽，有效提高了凹槽侧壁的陡直性，进而提高了驱动梁内部电场的激励效率和陀螺灵敏度。采用有限元仿真的方法，分析了不同截面形状的驱动梁压电激励力的相对大小，优化设计了陀螺芯片结构参数。依据陀螺芯片的结构，设计了合理的工艺方案并在3英寸石英圆片上制作出了三种驱动梁截面形状的陀螺器件，测试结果表明，相对于矩形驱动梁截面的陀螺芯片，双“W”形驱动梁截面的陀螺芯片的灵敏度提高约60%。