The Effect of Mounting Stress on the Zero Point Output of Pressure Sensors

The objective of this research is to fundamentally understand the effect of the mounting stress on the zero point output of pressure transducers containing a piezoresisitve silicon based pressure sensor used in automobile electronics sensing. In this paper, the mounting process for the current packaging of the pressure sensor is described. The stress of the packaged pressure sensor changes when being mounted into the metal shell for satisfying the high hermeticity requirements. The changed stress of the process, which is called mounting stress, is discussed to investigate the performance of the pressure transducer by both numerical simulations and experimental tests. In the paper, a simplified symmetrical three-dimensional finite element model of the pressure transducer system is established by a commercial software ANSYS. The mounting stress distributions are shown by the modeling, and the results demonstrate that zero shift of the system becomes almost proportional to the amount of mounting pressure. In addition, the experimental results for the mounting process agree with the numerical results in the trend. Finally, an amended packaging system with a ceramic base for the pressure sensor is proposed in the research, and both the experimental tests and numerical simulations are conducted to demonstrate the better performance on the zero shift of the amended packaging