Design Of High G Anti-overload Acceleration Sensitive Chip

Micro-Electro-Mechanical System(MEMS)technology,is a kind of micro semiconductor manufacture technologies based on integrated circuit technology.Since it has the huge advantage witch is hardly been surpassed by traditional mechanical manufacture technologies,it has aroused attention since its advent.Depending on the electrical characteristics and mechanical properties of semiconductors,MEMS sensor has been the best choice of the replacement of mechanical sensor.MEMS piezoresistive acceleration sensitive chip which produced by silicon materials,has a simple working principle,low fabricating cost and mature technology.It has become the main product of micro acceleration sensitive manufacturers.So far,general acceleration chip mainly uses cantilever beam and mass block structure.The structure is simple and runs steadily,but it is hard to adapt to the complex weapon application environment for its serious defects of structure.It also limits the promotion of the performance of the key parts of weapons.In order to make the MEMS piezoresistive acceleration sensitive chips suitable for high overload environment,improve the overall performance of micro sensors,now modify the structure of the general acceleration sensitive chip,design a kind of acceleration sensitive chip structure with micro beam.This structure solves the contradiction between the sensitivity and natural frequency of the chip,and makes the chip possess high overload resistance.Through the optimization of the structure of chip,a method of etching grooves is adopted to solve the problem of the cross coupling of the structure of chip.Under the condition of full range100,000 g,the chip's output voltage is 21.42 mV with the power supply 1mA constant current after optimization analysis.The natural frequency of the chip is 1.025 MHz,the chip's highest cross coupling is 4.24%.The chip can bear 650,000 g shock at least.Based on the optimization of the chip structure,two types structure optimization methods are proposed.The specific parameters of the chip structure are determined by using these two methods.The chip's layout and technological process are given after selecting the beat chip structure.