MEMS热式风速风向传感器输出性能优化研究

Research on Performance Optimization for MEMS Thermal Wind Speed and Direction Sensor

环境测温二极管在工作时受传感器芯片热场影响,常引发MEMS热式风速风向传感器加热电压-风速曲线异常。将其更换为外置测温二极管,并调整其与传感器芯片距离,成功解决了输出曲线异常现象。并在此基础上,优化芯片及外置测温二极管的封装方案,消除了热场的相互干扰和不必要的热损耗,同时保证了外置测温二极管与空气的良好接触。风场测试结果表明,传感器的加热电压-风速曲线变得平滑,且重复性好,风速和风向的测量误差分别在±4%和±4°以内,系统的上电稳定时间大幅缩短至15 s左右。

The environmental temperature sensing diode is always influenced by the thermal field of the sensor chip,which leads to the abnormal heating curve of the MEMS thermal wind speed and direction sensor.In order to solve this problem,the diode was replaced by an external diode and the distance to the sensor chip had been increased in this paper.Consequently,the abnormal points in the curve had been disappeared.On this basis,the package scheme for the sensor chip and the surrounding temperature sensing diode had been optimized.It could not only eliminate the mutual interference between the thermal field and unnecessary heat loss as far as possible,but also guarantee good contact between the air and the temperature sensing element.The wind experiments demonstrate that the heating voltage-wind speed curve of the sensor is smoother with a good repeatability.The measurement errors of wind speed and wind direction are less than±4%and±4°,respectively.Moreover,the power-on stability time of the sensing system has been reduced to about 15 s.