MEMS加速度计横向输出抑制技术

Transverse output suppression technology of MEMS accelerometer

建立了微机电系统(MEMS)结构的力学模型,分析了横向输出产生的根本原因;基于压阻效应,充分利用对称结构和电桥的抵消作用抑制横向输出;利用MEMS体硅工艺制作了量程100 gn的加速度芯片。讨论了加工、封装、测试过程中引入的敏感轴偏离,提出了解决方案。测试结果表明:样品横向灵敏度比可以达到1%,能够满足国防、汽车、工业、消费电子等各领域的应用需求。

A micro-electro-mechanical system (MEMS)structure mechanical model is constructed,analyze on fundamental reason how the transverse output produced.Based on piezoresistive effect,take full advantage of symmetrical structure and bucking effect of the Wheatstone bridge to restrain transverse output.The 100gn chip is fabricated using MEMS bulk micromachining process.Sensitive axis deviation brought in fabrication packaging,and testing is discussed,and solution is proposed.The sample test result shows transverse sensitivity ratio can reach 1%,which can meet application requirements in fields such as national defense,automobile,industry and consumer electronics.