STRAIN GAUGE OF ABSOLUTE PRESSURE BASED ON SOI MICRO-ELECTROMECHANICAL SYSTEM Russian patent published in 2017 - IPC G01L9/04 

FIELD: measuring equipment.

SUBSTANCE: invention relates to measurement equipment, particularly to equipment for measuring non-electric values, namely, to strain gauges of absolute pressure based on a silicon-on-insulator (SOI) micro-electromechanical system. Strain gauge of absolute pressure comprises a body with a tube to feed the measured pressure made of a metal plate-base and a metal cover, inside which there is an electric circuit of switching the strain transducer with an external electrical circuit and a rigidly fixed absolute pressure cell (APC). Herewith the APC consists of a chip of the strain transducer with a Wheatstone measuring bridge, a glass pedestal and a vacuum-treated cavity. Herewith the strain transducer chip is made on the basis of a SOI-heterostructure consisting of two single-crystal silicon plates separated by an intermediate thin layer of an inorganic dielectric, wherein in the upper plate there is a monolithic strain frame, and in the lower one there are a trapezoidal recess and a membrane both forming the vacuum-treated cavity as the result of a tight connection of the strain transducer chip with the pedestal along a strip on the pedestal perimeter. APC pedestal is made in the form of a square plate from Pyrex glass and is rigidly fixed on the plate-base in a seat made in the form of a blind hole with a stepped profile, and the monolithic strain frame consists of four volume strain gauges of equal length and equal cross section, which form the Wheatstone measuring bridge. Measured pressure feed tube is installed in the body cover on the strain transducer chip working surface side. Electric circuit of switching is made in the form of a flexible loop based on a polyimide film, which with band leads at one end is connected electrically to contact pads of the strain transducer chip, and on the other end of the loop there is a row of contact pads for connection with the external electrical circuit, conductors and microcontacts of the flexible loop are protected with a fine inorganic film.

EFFECT: technical result is higher time stability and reliability, wider range of the sensor operating temperatures, its reduced sensitivity to gamma-radiation.

3 cl, 2 dwg