阈值可调的微机电惯性开关

摘要

针对惯性开关通用性的要求，设计了一种具有阈值可调功能的微机电惯性开关。利用CoventorWare软件中的Architect模块对该悬臂梁结构开关进行系统级仿真。仿真结果表明，开关在半正弦加速度信号作用下，加速度阈值和电压基本呈线性关系，通过调整偏置电压的方式，可测量不同阈值加速度；以500g为一档，调节加速度阈值范围为1000~4000g，开关最长响应时间为63.44μs，接触时间无穷大，表现出良好的工作性能。考虑MEMS薄膜沉积工艺在加工4μm厚的悬臂梁时存在±0.1μm加工误差，应用蒙特卡洛法分析悬臂梁厚度在3.9~4.1μm之间变化时，对开关吸合电压和闭合时间的影响，结果表明，±0.1μm的加工误差对开关吸合电压和闭合时间影响在设计允许范围内。%In view of the versatility requirement of the inertial switch in fuze, a novel inertial switch with threshold adjusting is designed. The systemic model of the cantilever MEMS switch was established in CoventorWare(Architect module), and the static and the dynamic characteristic were studied based on the systemic model. The simulation results show that the acceleration threshold present an almost liner relationship with the changed bias voltage, and the acceleration threshold can be adjusted by adjusting the bias voltage of the switch. The acceleration threshold is controlled from 1000g to 4000g, adjusting 500g every time. The longest response time of the switch is 63.44μs, and the contact time is infinite, showing a higher trigger sensitivity and a favorable contact effect. The depth of the 4-micron-thick silicon cantilever would have ±0.1μm actual error during depositing process, so the Monte Carlo method was used to calculate the pull-in voltage and the performance of switch when the thickness of cantilever changed between 3.9~4.1μm during simulation moment. The simulation results show that the cantilever error is ±0.1 μm, whose influence on the switch’s pull-in voltage and the response time was within the design index.