Method for producing capacitive ceramic absolute pressure sensors sorted in zero-point long-term stability defect classes

Abstract From the Canadian patent

In this method for producing capacitive alumina-ceramic absolute pressure sensors sorted in high-precision zero-point long-term stability defect classes referred to a measured-value span csp, the sensors are firstly produced conventionally: a substrate is provided with an annular first electrode and, at the center, a circular second electrode insulated from the first; a diaphragm is provided with a third electrode, and the substrate and diaphragm are joined tightly together in a vacuum by the mutually facing electrodes, at an outer edge through the interposition of an active brazing ring with the formation of a chamber with the result that a pressure-dependent capacitance Cp and a …