Single-sided differential pressure sensor

Abstract

A single-sided differential pressure sensing chip having a cavity formed in the top surface of a substrate, a deformable diaphragm spanning the cavity, and a pressure passage connecting the top surface of the substrate with the cavity, and a method of making the same are described. A first fluid pressure applied to the top surface of the substrate in the vicinity of the diaphragm exerts a force on the top surface of the diaphragm, and a second fluid pressure applied to the top surface of the substrate near the pressure passage exerts a force on the bottom surface of the diaphragm. The diaphragm deflects in response to the forces exerted upon it, and a sensing element detects the flexing of the diaphragm. The pressure sensing chip can be contained within a housing structure formed of a carrier and a cap. The housing structure forms a first pressure chamber that communicates with the top surface of the diaphragm and a second pressure chamber that communicates with the bottom surface of the diaphragm through the pressure passage. The cap can include a first opening for connecting a first fluid pressure with the first chamber, and a second opening for connecting a second fluid pressure with the second chamber.