In-Situ Pressure Measurements of Encapsulted Gyroscopes

This paper presents new type of test structures based on the Pirani principle. They were realized together with a gyroscope in a 50 μm SOI (silicon-on-insulator)-based technology to measure the encapsulated pressure of Coriolis vibrating gyroscopes (CVG) but might also be adapted to other devices. Design and optimization of the test structures was carried out by an analytical model that accounts for the main technological parameters and enables a good estimate of the precision of the developed test method. The achieved measurement accuracy allows a good separation of encapsulated from non-encapsulated gyroscopes. Further improvements are expected by application of dynamic instead of static test methods.