Pressure sensing device with stepped cavity to minimize thermal noise

摘要

A pressure sensing element may include a diaphragm and a stepped cavity. The pressure sensing element may include a plurality of piezoresistors, which are operable to generate an electrical signal based on an amount of deflection of the diaphragm in response to a sensed pressure of the fluid. The pressure sensing element may be mounted onto a housing substrate using an adhesive so that a portion of the adhesive is attached to walls of a first cavity and to a step surface of the stepped cavity to redistribute thermally induced stresses on the pressure sensing element. The stepped cavity may be included in a MEMS pressure sensing element to reduce or eliminate thermal noise, such as temperature coefficient of offset voltage output (TCO).