A number of physical principles are available for measuring mechanical quantities. For miniaturized sensors based on silicon and MST technologies, the piezoresistive measuring principle has proven to be versatile and robust. The measuring principle is of great importance for pressure sensors. The integrated piezoresistive measuring resistors react to strain or mechanical stress. They are integrated in a bending plate, which changes its mechanical stress state particularly selectively and pressure-dependently. The measuring resistors are arranged as a measuring bridge to increase the sensitivity and to compensate the temperature dependency.
For high-precision pressure measuring cells, the cost of calibration over the entire application range amounts to approx. 20-30 % of the manufacturing costs, due to the non-linear dependencies of the measurement signal on pressure and temperature.
With a new technology or orientation of the silicon, the development of layouts for the way and arrangement of the measuring resistors, which preferably use the longitudinal effect, a new sensor is realized. This optimization of the measuring bridge increases the linearity, reduces the temperature coefficient of the zero point as well as the measuring span.
This project approach promises a significant reduction of the calibration effort, potential sources of error and costs.
