Purpose

This paper aims to present an efficient design approach for the micro electromechanical systems (MEMS) accelerometers considering design parameters affecting the long-term reliability of these inertial sensors in comparison to traditional iterative microfabrication and experimental characterization approach.

Design/methodology/approach

A dual-axis capacitive MEMS accelerometer design is presented considering the microfabrication process constraints of the foundry process. The performance of the MEMS accelerometer is analyzed through finite element method– based simulations considering main design parameters affecting the long-term reliability. The effect of microfabrication process induced residual stress, operating pressure variations in the range of 10 mTorr to atmospheric pressure, thermal variations in the operating temperature range of −40°C to 100°C and impulsive input acceleration at different input frequency values is presented in detail.

Findings

The effect of residual stress is negligible on performance of the MEMS accelerometer due to efficient design of mechanical suspension beams. The effect of operating temperature and pressure variations is negligible on energy loss factor. The thermal strain at high temperature causes the sensing plates to deform out of plane. The input dynamic acceleration range is 34 g at room temperature, which decreases with operating temperature variations. At low frequency input acceleration, the input acts as a quasi-static load, whereas at high frequency, it acts as a dynamic load for the MEMS accelerometer.

Originality/value

In comparison with the traditional MEMS accelerometer design approaches, the proposed design approach focuses on the analysis of critical design parameters that affect the long-term reliability of MEMS accelerometer.

中文翻译：

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考虑微制造工艺限制和操作环境变化的双轴 MEMS 加速度计的有效设计

目的

本文旨在提出一种有效的微机电系统 (MEMS) 加速度计设计方法，与传统的迭代微制造和实验表征方法相比，考虑到影响这些惯性传感器长期可靠性的设计参数。

设计/方法/方法

考虑到铸造工艺的微制造工艺限制，提出了一种双轴电容式 MEMS 加速度计设计。考虑影响长期可靠性的主要设计参数，通过基于有限元方法的仿真分析了 MEMS 加速度计的性能。微制造过程引起的残余应力、10 mTorr 至大气压范围内的工作压力变化、-40°C 至 100°C 工作温度范围内的热变化以及不同输入频率值下的脉冲输入加速度的影响如图所示细节。

发现

由于机械悬挂梁的有效设计，残余应力对 MEMS 加速度计性能的影响可以忽略不计。操作温度和压力变化对能量损失系数的影响可以忽略不计。高温下的热应变导致传感板变形出平面。室温下的输入动态加速度范围为 34 g，随着工作温度的变化而减小。在低频输入加速度下，输入充当准静态负载，而在高频下，它充当 MEMS 加速度计的动态负载。

原创性/价值

与传统的 MEMS 加速度计设计方法相比，所提出的设计方法侧重于分析影响 MEMS 加速度计长期可靠性的关键设计参数。