SOI-based, High Reliable Pressure Sensor with Floating Concept for High Temperature Applications

Abstract

In this paper we present a high reliable, accurate and safe, solid state pressure sensor for high temperature applications. The sensor is based on an unique fluid-free technology using a piezoresistive SOI-based chip enclosed in a sealed metal housing. The proprietary housing concept allows a complete separation of the SOI-chip from the measured media. A thick steel membrane and an elongated member (push-rod) transfer the outside pressure into a small deflection of a silicon membrane on the SOI-chip. The thin silicon membrane is engraved by DRIE (Deep Reactive Ion Etching). The sensor is capable to measure pressures up to 1000bar at temperature up to 400°C with an accuracy of ±0,50%FSO. A digital correction enables a compensation of Offset and Sensitivity thermal drifts. The sensor can undergo long-term extreme working conditions without losing its performances.