Media isolated pressure transducer having boss comprising single metal diaphragm

A sensing system, comprising:

• a housing including at least a first port for coupling to a fluid for measurement of a pressure of said fluid;
• at least one sensor in said housing including a pressure sensor for sensing pressure of said fluid, said sensor pressure comprising:
• a monolithic substrate comprising metal and further having a substantially planar top side, wherein said substrate comprises a relatively thick boss near a center of said substrate and a thinned sensing portion that is elastically deformable and pressure-sensitive radially outward from said boss;
• at least one dielectric layer on said top side of said substrate;
• a plurality of piezoresistors on said dielectric layer, wherein said piezoresistors are positioned over said thinned diaphragm portion;
• at least one overglaze layer that provides apertures for electrically connecting to said plurality of piezoresistors;
• and
• an end cap;
• wherein said pressure sensor is secured to said end cap, and said end cap is secured to said housing to form a hermetically sealed sensor system that prevents said fluid from reaching said topside of said of said substrate.

A method of making a pressure sensor, comprising:

• providing a metal containing substrate having a substantially planar top surface, said substrate comprising a boss near a center of said substrate and a thinned sensing portion that is elastically deformable and pressure-sensitive positioned radially outward from said boss;
• forming an ATF stack directly on said top surface of said substrate, including the steps of:
• forming one or more dielectric layers on said top surface of said substrate;
• forming an electrical conductive layer including a wiring network;
• and
• forming piezoresistors, some of which being in electrical communication with said wiring network.