摘要
设计、制造并测试了一种单片集成的压阻式高性能三轴高g加速度计,量程可达105g.x和y轴单元均采用一种带微梁的三梁-质量块结构,z轴单元采用三梁-双岛结构.与传统的单悬臂梁结构或者悬臂梁-质量块结构相比,这两种结构均同时具有高灵敏度和高谐振频率的优点.采用ANSYS软件进行了结构分析和优化设计.中间结构层主要制作工艺包括压阻集成工艺和双面DeepICP刻蚀,并与玻璃衬底阳极键合和上层盖板BCB键合形成可以塑封的三层结构,从而提高加速度计的可靠性.封装以后的加速度计采用落杆方法进行测试,三轴灵敏度分别为2.28,2.36和2.52μV/g,谐振频率分别为309,302和156kHz.利用东菱冲击试验台,采用比较校准法测得y轴和z轴加速度计的非线性度分别为1.4%和1.8%.
A silicon machined high-performance monolithic triaxial piezoresistive accelerometer is developed for measurements on the order of 100,000g. A three-beam-mass scheme with tiny beams is developed for the x and y axial elements, and a three-beam-twin-mass structure is developed for the z axial element. Both of these structures feature high sensitivity and high resonance frequency compared with a conventional cantilever structure or cantilever-mass structure. ANSYS is used to analyze and optically design the accelerometer. The three sensing elements are monolithically integrated by micromachining techniques of double-sided deep etching combined with piezoresistive processes. The middle structure silicon layer is anodic bonded with glass substrate and BCB bonded with a top cap silicon layer for the purpose of plastic packaging to improve the reliability of the accelerometer. A dropping-bar system is used to characterize the accelerometer. The sensitivities in the x, y, and z axes are measured to be 2.28,2.36,and 2.52μV/g, respectively,while the corresponding resonant frequencies are 309, 302,and 156kHz. Using a Dongling shock test machine,the nonlinearity is tested by comparison calibration and measured to be 1.4% and 1.8% for the y and z axial elements,respectively.
关键词
硅微机械加工技术
三轴加速度计
压阻
高g
塑封
silicon micromachining technology
triaxial accelerometer
piezoresistive
high-g
plastic package
