James Knutti

US Patent:

7111518, Sep 26, 2006

Filed:

Sep 19, 2003

Appl. No.:

10/665991

Inventors:

Henry V. Allen - Fremont CA, US
Stephen C. Terry - Palo Alto CA, US
James W. Knutti - Fremont CA, US

Assignee:

Silicon Microstructures, Inc. - Milpitas CA

International Classification:

G01L 7/08
G01L 9/00

US Classification:

73715

Abstract:

Methods and apparatus for an absolute or gauge pressure sensor having a backside cavity with a substantially vertical interior sidewall. The backside cavity is formed using a DRIE etch or other MEMS micro-machining technique. One embodiment provides for a diaphragm having a boss manufactured using a two step process that results in a boss thickness that is independent of the thickness of the starting material. Another provides for various shapes to the backside cavity that reduces the likelihood of crystalline fractures while focusing stress on piezoresistive sensing elements. Another provides for a sensitivity adjustment by thinning the insulating and silicon layers that form the sensor diaphragm. A pressure sensor according to the present invention may incorporate one or more of these, or may incorporate other elements discussed herein.

US Patent:

45434573, Sep 24, 1985

Filed:

Jan 25, 1984

Appl. No.:

6/573509

Inventors:

Kurt E. Petersen - San Jose CA
Henry V. Allen - Fremont CA
James W. Knutti - Fremont CA

Assignee:

Transensory Devices, Inc. - Fremont CA

International Classification:

H01H 3534

US Classification:

200 83N

Abstract:

A microminiature switch for digitizing different-valued external conditions, such as pressure, temperature of acceleration, is disclosed. The switch includes a silicon wafer having a deflectable, reduced-thickness membrane adapted to move from a relaxed position toward increasingly flexed or bulged positions in response to greater-value changes in such external condition. Movement of the membrane from its relaxed position to more strained positions establishes electrical contact between a common terminal and first one and then progressively more switch-state terminals in the switch, wherein the number of switch states which are closed corresponds to the external condition acting on the switch.

US Patent:

48614203, Aug 29, 1989

Filed:

Jul 14, 1987

Appl. No.:

7/073675

Inventors:

James W. Knutti - Fremont CA
Henry V. Allen - Fremont CA
Kurt E. Petersen - San Jose CA
Carl R. Kowalski - Fremont CA

Assignee:

Tactile Perceptions, Inc. - Fremont CA

International Classification:

H01L 2984
G01L 118

US Classification:

156633

Abstract:

A semiconductor transducer (10) including a substrate having a well (18) formed in one surface thereof and a semiconductor layer (14) having a first surface (26) bonded to the substrate about the periphery of the well to form a diaphragm (30) and a second surface (28) which is substantially parallel to the first surface and has a pedestal (16) projecting therefrom which is disposed above the well. The side walls (32) of the pedestal are substantially orthogonal to the second surface of the semiconductor layer and are formed by sawing edge portions of said semiconductor layer. The substrate includes structures (38) which extend upward from the bottom of the well to limit the deflection of the diaphragm.

US Patent:

46806067, Jul 14, 1987

Filed:

Jun 4, 1984

Appl. No.:

6/617122

Inventors:

James W. Knutti - Fremont CA
Henry V. Allen - Fremont CA
Kurt E. Petersen - San Jose CA
Carl R. Kowalski - Fremont CA

Assignee:

Tactile Perceptions, Inc. - Fremont CA

International Classification:

H01L 2984
G01B 716

US Classification:

357 26

Abstract:

A semiconductor transducer (10) including a substrate having a well (18) formed in one surface thereof and a semiconductor layer (14) having a first surface (26) bonded to the substrate about the periphery of the well to form a diaphragm (30) and a second surface (28) which is substantially coplanar to the first surface and has a pedestal (16) projecting therefrom which is disposed above the well. The side walls (32) of the pedestal are substantially orthogonal to the second surface of the semiconductor layer. Means (34) are provided for sensing the deflection of the diaphragm as a function of force applied to the pedestal. The substrate includes protrusions (38) which extend upward from the bottom of the well to limit the deflection of the diaphragm.