低热零点漂移的高温绝压压力传感器

High Temperature Absolute Pressure Sensor with Low Thermal Zero Drift

传统的高温绝压压力传感器一般采用硅和玻璃进行阳极键合来制备绝压腔。由于高温环境下硅片和硼硅玻璃的热膨胀系数不匹配,从而产生较高的热零点漂移。文中提出了一种低热零点漂移的压力传感器设计方案,由硅-玻璃-硅的三层结构代替普通的双层阳极键合结构,并给出了热力学仿真模型。分析表明:改变传感器硅与玻璃的结构比例,实现应力匹配可以有效减小热应力。对芯片进行了高温实验测试,发现传感器的热零点漂移变化率减小了50%。

The traditional high temperature absolute pressure sensor usually uses silicon and glass anode bonding to prepare the absolute pressure chamber.Due to the mismatch of thermal expansion coefficient of silicon wafer and borosilicate glass in high temperature environment,high thermal zero drift occurs.In this paper,a design scheme of pressure sensor with low thermal zero drift was proposed.The three-layer structure of silicon-glass-silicon was used to replace the common double-layer anode bonding structure,and the thermodynamic simulation model was given.The analysis shows that changing the structural ratio of the sensor silicon and glass to achieve stress matching can effectively reduce thermal stress.The chip is tested at high temperature,and it is found that the thermal zero drift rate of the sensor was reduced by 50%.