Accelerometer performance can be characterized by two main parameters; bias value and scale factor (SF) stability. In order to decrease the temperature sensitivity of silicon resonant accelerometer, a deep research on the temperature influencing mechanism was conducted in this paper. Through temperature experiment on silicon resonant accelerometer, a great difference was found between the testing output and the designed theoretical parameters of bias value and SF. Both bias value and SF show obvious temperature sensitivity, which are 0.72 g/℃ and 1.5 ℃-1 , respectively. The theoretical calculation and FEA simulation of the effects of elastic modulus and resonator stress on frequency of resonators were carried out. The temperature sensitivities of resonant frequency caused by Young modulus and resonator stress are -0.7 Hz/℃ and 180 Hz/℃ , respectively. The reason why bond stress is produced and its connection with residual stress of resonator are discussed. It is validated that resonator stress is the main factor in causing temperature drift of accelerometer output. A design method of isolation beam was presented to isolate residual stress, which can decrease temperature sensitivity of bias value to -35 Hz/℃ , thus pointing out the direction of accurate compensation.%零偏和标度因数稳定性是衡量加速度计性能的两个重要参数.为了降低硅微谐振式加速度计的温度敏感性,对其温度影响机理进行了深入研究.通过温度实验发现,硅微谐振式加速度计的零偏和标度因数与设计理论参数有较大区别,且都具有较大的温度灵敏度,分别为0.72g/℃和1.5℃-1.对弹性模量和谐振器应力与谐振器频率的关系进行了理论计算和FEA仿真验证,其中弹性模量引起的谐振频率-温度灵敏度为-0.7Hz/℃,谐振器应力引起的谐振频率-温度灵敏度为180Hz/℃.阐述了加工过程中键合应力产生的原因以及键合应力与谐振器残余应力的关系,发现谐振器应力是造成加速度计输出随温度漂移的主要因素.提出了一种隔离残余应力的隔离梁的设计方案,可使零偏温度灵敏度降至-35H/℃,为温度补偿指明了方向.
展开▼
