一种新型压阻式微加速度计的研究与设计

对于广泛采用的压阻式微加速度计,在传统工艺下,提高量程和固有频率意味着增加梁厚,减小应力,而提高灵敏度又要求减小梁厚,这是相互矛盾的。设计了一种4边4梁结构的高过载压阻式微加速度计,在传统梁-岛结构微加速度计的基础上进行了改进,采用主梁和微梁相结合的设计思想,在提高固有频率、量程的同时提高了灵敏度。在梁的末端采用了新式的延伸梁结构设计,有效地消除了集中应力的现象,提高了结构的抗过载能力。对其进行了阻尼分析和压阻元件的设计,并给出了可行的版图设计方案。仿真结果表明,该微加速度计的各项指标均满足设计要求,具有明显的优越性。

Research and Design of a New High Micro piezoresistive Accelerometer

For micro piezoresistive sensors widely used in the traditional process, to improve the range and natural frequency means to increase the beam thickness and reduce stress;while to improve the sensitivity requires reducing the beam thickness,which are mutually contradictory.A four beam structure of the high overload micro piezoresistive accelerometers was designed for improvement on the basis of the traditional beam island structure.A complementary structure with combination of main beams and micro beams was adopted to improve the natural frequency and the range;at the same time,the sensitivity was also improved.A new design of extending beam was proposed at the end of the beam structure, which greatly reduced the stress concentration phenomenon and improved the ability of anti overload of the structure. Moreover,the damping was analyzed and piezoresistive element was designed,the feasible layout design scheme was given. Simulation result showed the indicators of the high overload micro accelerometer could meet the requirements with obvious advantages.