A performance prediction model for a piezoresistive transducer pressure sensor

The performance of a piezoresistive transducer pressure sensor to thermal and pressure environments can be predicted by the finite element method. A simplified 1/8 model, considering silicon dioxide and nitride processes as well as stack-anodic bonding and adhesive bonding processes, was developed. The FEM results were found to be comparable to experimental data. Case studies suggested that a Pyrex stack induces a certain amount of non-linearity, while it isolates the hard epoxy nonlinear effect. Flexible epoxy bonding or soft adhesive bonding is preferred for the packaging process. The viscoelasticity and viscoplasticity of the bonding material will result in hysteresis and drift errors of the sensor output. However, the soft adhesive´s influence on the sensor can be ignored under relatively stable environments. Moreover, detailed design and process information will help to improve the modeling application.