Direct calculation of sensor performance in an FEA model [MEMS]

A method of using FEA software in direct calculation of the performance of MEMS pressure sensors is described. The pressure sensor is one of a family of MEMS pressure sensors, which use a piezo-resistor bridge on a silicon diaphragm as the transducer. The sensor model includes level-0 packaging and the geometry is parametric so that it can easily be applied to design variations. The method computes the resistance of the piezo-resistors by calculating the piezo-resistance in each finite element. Then an accurate total resistance is calculated as a function of pressure and temperature, from which the transducer signal is estimated. The transducer signal is described in terms of the sensitivity, linearity and offset. The sensitivity matches the measured data within the one standard deviation of the measured values. Deviation from linear is within 0.2% of the measured values. Not all of the significant factors that contribute to the offset have been included in this method.