Silicon diaphragm pressure sensor having improved configuration of integral strain gage elements

Claim 1

A piezoresistive strain gage comprising: a. a diaphragm formed of a monocrystalline material having a restrained outer portion and a strain-sensing inner portion adapted to be subjected to a pressure to be measured; b. semiconductor strain gage elements formed integrally on one surface of said diaphragm by diffusion, said strain gage elements being in the form of a plurality of elongated strips arranged parallel to a preselected crystallographic axis of said diaphragm and further arranged on the strain-sensitive area of the diaphragm in four sections with two of the sections in an area where they are subject to tensile strain and the other two sections in an area where they are subject to compressive strain; c. a plurality of interconnect areas also formed integrally on said surface of the diaphragm by diffusion in locations electrically to connect all of the strain gage elements and sections in series circuit relation with the sections subject to tensile and compressive strains alternately arranged in the series circuit; and d. circuit connecting means for making electrical connections to the interconnect areas extending between the four sections of the strain gage elements to form a Wheatstone bridge type of measuring circuit.