Mechanical analysis of pressure transducers with two-sided overload protection

Abstract

Computational mechanics is used to analyse and design a new class of subminiature differential pressure transducers. Double-sided overload protection for a planar transducer is achieved with a metal stop, produced by a process involving X-ray lithography and precision electroplating. The metallic stops limit motion, suppress diaphragm stress and facilitate the option of a second signal to verify performance. Finite element stress analysis shows that the proposed device can generally sustain pressures substantially greater than those producing initial contact between the diaphragm and the overload stop. Mechanical stresses are minimized by thick stops but thermal stresses are lowest for thin stops. However finite element thermal strain computations indicate that interface stress does not increase monotonically with stop thickness.