Differential pressure sense die based on silicon piezoresistive technology
AssigneeHoneywell International Inc.
InventorLamar F. Ricks
Life of this patent
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Abstract
A method and apparatus for designing a differential pressure sense die based on a unique silicon piezoresistive technology for sensing low differential pressure in harsh duty applications is disclosed. The pressure sense die comprises of an etched pressure diaphragm and a hole that is drilled through the sense die wherein the pressure sense die possess a backside and a front side and are associated with varying pressures. A top cap can be attached to the front side and an optional constraint for stress relief can be attached to the backside of the differential pressure sense die. The top cap and the constraint comprise of glass and/or silicon and can be attached with an anodic bonding process or glass frit process.
Claims18
A method for providing differential pressure sense die utilized in a pressure sensor, comprising:
- etching a separate hole through a pressure sense die having a pressure diaphragm wherein said pressure sense die comprises a back side and a front side and are respectively associated with a plurality of varying pressures;
- forming a piezoelectric sensing network as part of said pressure sense die 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;
- and
- 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.
A differential pressure sensing apparatus, comprising:
- a pressure sense die configured to include a separate hole etched through said pressure sense die, said pressure sense die having a pressure diaphragm wherein said pressure sense die further comprises a back side and a front side and are respectively associated with a plurality of varying pressures;
- a piezoelectric sensing network formed as part of said pressure sense die wherein said piezoelectric sensing network comprises a plurality of piezoresistors, a conductor and a plurality of electrical conductors;
- a top cap attached over said front side utilizing a bonding process wherein said top cap and said pressure sense die together form a reference pressure cavity therebetween;
- and
- a constraint attached 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.
Dependencies are inferred from the claim text.