采用微机械电子系统(Micro Electro-Mechanical Systems,MEMS)和硅隔离(Silicon on Insulator,SOI)技术制作出了量程为25MPa的倒杯式耐高温压阻力敏芯片,敏感电阻条与硅基底之间采用二氧化硅隔离,解决了在大于120℃高温下力敏芯片工作稳定性和可靠性的难题。设计了齐平式机械封装结构,避免了管腔效应影响,提高了传感器的动态响应频率。对研制出的耐高温动态压力传感器进行了静态性能和动态性能的标定实验,静态实验温度为250℃,得到了传感器基本性能参数,分析了传感器的不确定度,得出该传感器的基本误差为±0.114%FS(Full Scale,全量程),不确定度为0.01794mV,计算得到了传感器的热零点漂移和热灵敏度漂移指标,由动态性能实验得到传感器的响应频率为555.6kHz,实验表明所研制的MEMS压力传感器在高温下具有良好的精度和固有频率。
The inverted cup-type high-temperature piezoresistive pressure sensitive chip with the range of 25MPa was developed by the Micro Electro Mechanical Systems (MEMS) and Sili- con on Insulator (SOl) technology. The sensitive piezoresistors are isolated from the silicon sub- strate by the silicon dioxide, and thus the stability and reliability problems of the pressure sensi- tive chip are solved at high temperatures beyond 120℃. The flush-type mechanical packaging structure was designed to avoid the channeling effect and improve the dynamic response frequency of the sensor. For the fabricated high temperature dynamic pressure sensor, the static and dy- namic performance experiments were carried out to obtain the sensor's fundamental performance and analyze its uncertainty at the static experimental temperature of 250℃. The results show that the sensor accuracy is ±0. 114%FS and the uncertainty is 0. 017 94mV. The thermal zero drift and thermal sensitivity drift were calculated. The dynamic response frequency was calculated as 555.6 kHz through dynamic performance experiment. Therefore, the developed MEMS pressure sensor has fine accuracy and high natural frequency at high temperatures.