A substrate energy dissipation mechanism in in-phase and anti-phase micromachined z-axis vibratory gyroscopes
A substrate energy dissipation mechanism in in-phase and anti-phase micromachined z-axis vibratory gyroscopes
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DOI：
10.1088/0960-1317/18/9/095016
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发表时间：
2008-09-01
影响因子：
2.3
通讯作者：
Shkel, Andrei M.
中科院分区：
文献类型：
--
作者：
Trusov, Alexander A.;Schofield, Adam R.;Shkel, Andrei M.
分析了真空驱动同相和反相驱动Z轴振动微机械陀螺的能量耗散机理。实验证明，驱动类型是影响能量耗散的关键因素。对于同相器件，通过芯片基板的耗散是主要的能量损失机制。这种减振机制很大程度上依赖于模具安装方法；刚性模具安装以减少振动和应力隔离为代价，将能量损失降至最低。对于反相驱动的器件，抑制了通过基板的损耗，并提供了对外部振动的免疫力。然而，即使在反相驱动器件中，制造缺陷也会引入结构非对称性，使得能量能够由于动量不平衡而通过芯片基板耗散。在实验研究的基础上，提出了芯片基板能量耗散的分析模型，并利用该模型研究了驱动方式、芯片附着性和制造缺陷对能量耗散的影响。同相器件的极限Q因数一般小于20×10(3)，而平衡反相驱动陀螺仪的Q因数远高于100×10(3)。
This paper analyzes energy dissipation mechanisms in vacuum-operated in-phase and anti-phase actuated micromachined z-axis vibratory gyroscopes. The type of actuation is experimentally identified as the key factor to energy dissipation. For in-phase devices, dissipation through the die substrate is the dominant energy loss mechanism. This damping mechanism depends strongly on the die attachment method; rigid die attachment minimizes the loss of energy at the cost of reduced vibrational and stress isolation. For anti-phase actuated devices, dissipation through the substrate is suppressed and immunity to external vibrations is provided. However, even in anti-phase actuated devices fabrication imperfections introduce structural non-symmetry, enabling dissipation of energy through the die substrate due to momentum imbalance. Based on the experimental investigation, an analytical model for energy dissipation through the die substrate is proposed and used to study the effects of the actuation type, die attachment and fabrication imperfections. The limiting Q-factor for in-phase devices is generally below 20 x 10(3) while Q-factors much higher than 100 x 10(3) can be achieved with balanced anti-phase actuated gyroscopes.