摘要
为了保证高量程加速度计在冲击过程中的可靠性、有效性,减小其失效几率,以Hopkinson杆作为加载手段,采用激光干涉法对量程为1.0′10~5 g_n的4端全固支压阻式梁-岛结构微加速度计进行冲击试验,并分析了高量程加速度计抗过载能力及在冲击环境下失效模式和失效机理。试验中抽样对同种结构的10只传感器分别进行了冲击测试,根据测试结果可知,该结构的微加速度计抗过载能力为1.3′10~5g_n。通过分析可知失效模式主要表现为微结构梁的断裂、裂纹、键合点脱落现象。通过研究失效模式产生的原因发现,造成结构出现断裂、裂纹现象的原因主要有两种：一是重复连续冲击测试引起微结构疲劳产生失效;二是由于在冲击过程中加速度计芯片与该过程中产生的高频信号分量发生共振导致过载瞬间增大加速度计芯片结构位移失控使结构失效。通过采用不同手段完善传感器结构,提高了其可靠性。
In order to guarantee the validity and reliability of high-range accelerometer in the process of impact and reduce its failure probability, a Hopkinson-bar laser shock test was carried out for the measured range of 1.0′10~5g_n micro-accelerometer with four-pole fixed-beam structure. Meanwhile the shockresistibility of accelerometer was studied, and the failure mode and failure mechanism of high-range accelerometer in shock environment were discussed. In the test, 10 accelerometers with the same kind of structure were sampled to conduct the shock test. Test results show that the shock-resistance capability of the micro-accelerometer is 1.3′10~5 g_n. The cantilever fracture, cantilever crack, and wire bond shearing on the beam are the main failure modes of the micro-accelerometer. In the end, the causes of failure mode were analyzed, which show that there are two main factors that cause the fracture and crack of the cantilever： One is the repeating shock tests which lead to micro-structure fatigue failure, the other is the resonance between the sensor chip and the high-frequency signal in the shock test process, which instantly enlarges the overload and leads to the sensor＇s broken due to micro-structure displacement＇s out of control. Test results show that the reliability is improved through using several means to improve the structures of the acceleration sensors.
出处
《中国惯性技术学报》
EI
CSCD
北大核心
2015年第6期845-848,共4页
Journal of Chinese Inertial Technology
基金
国家自然科学基金杰出青年(51225504)
