Patent ID: 7644625
Filing Date: 2010-01-12
Classification: G01L

Abstract:
1. A method for providing a differential pressure sense die utilized in a pressure sensor, comprising: configuring a pressure sense die having a pressure diaphragms, said pressure sense die comprising a back side and a front side, wherein said pressure sense die detects a plurality of varying pressures; forming a piezoelectric sensing network upon said pressure diaphragm, wherein said piezoelectric sensing network comprises a plurality of piezoresistors, a conductor and a plurality of electrical conductors; attaching a top cap over said front side utilizing a bonding process, wherein said top cap and said pressure sense die together form a reference pressure cavity therebetween; forming a separate hole through said pressure sensing die into said reference pressure cavity to serve as a pressure inlet; attaching a constraint to said back side utilizing said bonding process and applying a sensed media to said pressure sense die wherein said top cap prevents a plurality of wire bonds and active regions associated with said front side of said pressure sense die from exposure to said sensed media and attack from acids and abrasive chemicals associated with said sensed media; measuring change in current flow through said plurality of piezoresistors wherein said change in current flow is caused by flexing of said diaphragm upon application of said plurality of varying pressures and is indicative of differential pressure.