High accuracy differential pressure capacitive transducer and method for making same.

摘要

A capacitive pressure transducer is disclosed in which a sensing diaphragm bearing an electrode is mounted to flex in response to applied fluid pressure relative to a reference member having an opposed electrode. A thin film or layer of dielectric material such as glass covers the reference member electrode and has formed therein a concavity matching the flexed curvature of the sensing diaphragm at its limit position. The dielectric layer has a high compressive strength and substantially enhances linearity by providing a substantially higher capacitance than the equivalent fluid-filled space. The transducer is retained within a transducer assembly under compressive preload, the assembly further including thermal strain relief means. Also disclosed are methods of making the transducer, which methods include thick film screen deposition techniques for forming concavities having preselected contours in the dielectric layer.