Carl C Stewart

US Patent:

6626044, Sep 30, 2003

Filed:

Oct 3, 2000

Appl. No.:

09/677895

Inventors:

Michael J. Haji-Sheikh - Richardson TX
Richard Alan Davis - Plano TX
Mark Robert Plagens - Richardson TX
Carl Edward Stewart - Plano TX
Gilberto Morales - Arlington TX

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L 708

US Classification:

73715, 73724, 73727, 3612834

Abstract:

A sensor having freeze resistant features is disclosed. The sensor includes a sensor die and a buffer member that are assembled for attachment to a process fluid conduit. The buffer member defines an opening in fluid communication with the process fluid. The sensor die has a flexible diaphragm, and a capillary channel establishes fluid communication between the diaphragm area of the sensor die and the opening in the buffer member.

US Patent:

6923069, Aug 2, 2005

Filed:

Oct 18, 2004

Appl. No.:

10/967536

Inventors:

Carl E. Stewart - Plano TX, US

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L009/00

US Classification:

73723

Abstract:

A pressure sensor includes a silicon diaphragm having bottom and topside surfaces. The bottom surface has been formed using methods known to those skilled in the art. A first layer is formed and patterned on the topside surface of the diaphragm having an area larger than the diaphragm. A second layer is formed and patterned over the first layer, the second layer being larger in area than the first layer. Holes formed in the second layer are used to remove the first layer using methods known to those skilled in the art. A third layer is formed and patterned over the second layer. The third layer seals the holes in the second layer creating a sealed cavity with a reference pressure on the topside surface of the diaphragm. During operation, media is applied to the bottom surface of the diaphragm wherein the media pressure can be sensed by the pressure sensor in relation to the reference pressure sealed on the topside of the diaphragm.

US Patent:

7216547, May 15, 2007

Filed:

Jan 6, 2006

Appl. No.:

11/328415

Inventors:

Carl E. Stewart - Plano TX, US
Gilberto Morales - Arlington TX, US

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L 7/00

US Classification:

73756, 73753, 257415

Abstract:

A pressure sensor apparatus and method that incorporates a silicon frit bonded cap. The pressure sensor includes a silicon sensor wafer with diaphragms at a bottom surface thereof, a silicon cap wafer mounted on the topside of each sensor wafer, a plurality of silicon sensor die formed on the sensor wafer, a silicon cap wafer etched to create a plurality of reference cavities on the topside of the diaphragm, a thin glass frit to form a wafer-to-wafer bond between the sensor wafer and cap wafer. Sensing devices such as semiconductor die/sensor, peizoresistors, can be used to sense the pressure. The wafer-to-wafer frit bonding improves the output signal drift and the thermal performance of the pressure sensor minimizes the thermal mismatch created by anodic bonded glass wafers.

US Patent:

7343812, Mar 18, 2008

Filed:

Jun 15, 2006

Appl. No.:

11/453509

Inventors:

Carl E. Stewart - Plano TX, US
Richard A. Davis - Plano TX, US

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L 7/00

US Classification:

73756, 438479

Abstract:

A pressure sensor includes a sensing element fabricated on an N-type epitaxial layer grown on a P-type substrate, a P-type isolation region located around the edge of the sensing element die and in contact with the P-type substrate, and a conductive elastomeric seal engaging the P-type isolation region prevents shorting of the conductive elastomeric seal with the N-type epitaxial layer of the sensing element die. A method of making a pressure sensor comprises growing an n-type epitaxy layer on a p-type substrate wafer, resulting in a pressure sensor die and substrate having an edge, obtaining a mask adapted for fabricating an isolation diffusion layer around the edge using P-type material, and creating an isolation layer diffusion using P-type doping material around the edge using the mask. A conductive elastomeric seal can then be placed over the sensor die to make electrical contact to the package.

US Patent:

7493822, Feb 24, 2009

Filed:

Jul 5, 2007

Appl. No.:

11/825237

Inventors:

Carl E. Stewart - Plano TX, US
Gilberto Morales - Arlington TX, US
Richard A. Davis - Plano TX, US

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L 9/06

US Classification:

73721, 438 53, 257419

Abstract:

A gauge pressure sensor apparatus and a method of forming the same. A constraint wafer can be partially etched to set the diaphragm size, followed by bonding to a top wafer. The thickness of the top wafer is either the desired diaphragm thickness or is thinned to the desired thickness after bonding. The bonding of top wafer and constraint wafer enables electrochemical etch stopping. This allows the media conduit to be etched through the back of the constraint wafer and an electrical signal produced when the etching reaches the diaphragm. The process prevents the diaphragm from being over-etched. The invention allows the die size to be smaller than die where the diaphragm size is set by etching from the back side.

US Patent:

7493823, Feb 24, 2009

Filed:

Jun 16, 2006

Appl. No.:

11/455040

Inventors:

Carl E. Stewart - Plano TX, US
Peter G. Hancock - Plano TX, US

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L 9/00

US Classification:

73754, 73756

Abstract:

A semiconductor-based pressure sensor adapted for enhanced operation with controls electronics includes a pressure transducer having an output formed on a silicon die and an amplifier having an input and an output and fabricated on the silicon die next to the pressure transducer. The pressure transducer's output is provided to the amplifier's input via electrical connection. Output from the amplifier is connectable to a controller such as an ASIC.

US Patent:

8297125, Oct 30, 2012

Filed:

May 23, 2008

Appl. No.:

12/126494

Inventors:

Carl Stewart - Plano TX, US
Richard Alan Davis - Plano TX, US
Gilberto Morales - Arlington TX, US

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L 13/02
G01L 15/00

US Classification:

73716, 73715, 73721

Abstract:

A differential pressure sensor includes two pressure ports for allowing media to pass into contact with both the top and bottom sides of the diaphragm. A silicon pressure sensor die can be attached between the pressure ports using die attach materials for sensing a differential pressure between the media to evaluate media differential pressure. A cap with an opening can be placed on topside of a diaphragm formed in the silicon pressure die. The silicon pressure die can include die bond pads that can be electrically connected to the diaphragm to output electrical signals. The cap can seal the die bond pads from the harsh media and route the electrical signals therein. Media can pass through the opening in the cap such that a media path to the top of the diaphragm is not exposed to the die bond pads of the silicon pressure die to ensure long-term sensor reliability.

US Patent:

8616065, Dec 31, 2013

Filed:

Aug 2, 2011

Appl. No.:

13/196743

Inventors:

Carl Stewart - Plano TX, US
Alistair Bradley - Hilliard OH, US
Lamar Ricks - Columbus OH, US

Assignee:

Honeywell International Inc. - Morristown NJ

International Classification:

G01L 9/06

US Classification:

73721, 73727

Abstract:

The present disclosure relates to sensors including pressure sensors. In some cases, the pressure sensor may include a membrane or diaphragm, multiple sense elements connected to one another in a bridge configuration and positioned on the membrane, and an amplifier coupled to an output of the bridge configuration and having an output, where the diaphragm, sense elements and amplifier may be formed on a singled substrate or formed integrally therewith, or both. In one example, the pressure sensor may sense a particular range of pressures applied to the sensor, and/or may include an amplifier that has a selectable gain for amplifying an output of the bridge.