Failure Mode Analysis of High g Value Sensor Based on Fault Tree

In order to study the possible failure mode of the high g acceleration sensor of the North University of China,this paper analyzed the composition and structure as well as established failure mode fault tree's system. Considering that the sensor is mainly used in shock environment,the key events: the sensor chip and the external amplifier circuit,which may happened in shock environment were simulated by finite element method. By using ANSYS,the sensor was simulated as the impact acceleration was gradually increased. The impact acceleration was determined at the time of the sensor chip and the external amplifier circuit exceed the allowable stress. Finally,three failure modes of the sensor were concluded in high g shock: the fracture of silicon beam,solder joint loss and the fracture of amplifier chip. And the recommendations were provided for improvements.