Patent US4359498A successfully refreshed from Google Patents.
US4359498A
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US
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Transducer structure employing vertically walled diaphragms with quasi rectangular active areas
Assignee: Kulite Semiconductor Products Inc
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Filing: 1981-04-20
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Granted: 1982-11-16
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Expires: 2001-04-20
Abstract
Abstract There is disclosed a rectangular diaphragm employing a quasi rectangular active area. The diaphragm as configured has an aspect ratio which is the length to width ratio of greater than 3:1. The active area of the diaphragm, which is the area which most readily deflects upon application of a force to the diaphragm, is formed by an anisotropic etching technique to provide steep vertical sidewalls. The diaphragm structure thus described exhibits as a response to an applied force or pressure, a maximum longitudinal stress and a minimum transverse stress and can accommodate piezoresistive elements located within the active area of the diaphragm.
Inventors
- 👤 Joseph R. Mallon
- 👤 Anthony D. Kurtz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:21
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052; G01L9/0054; G01L9/0042; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
97 words
A diaphragm for a pressure transducer for use with piezoresistors comprising: a rectangular planar monocrystalline semiconductor member having a predetermined crystallographic orientation of (110), having located on a major surface thereof a cavity of a parallelogram configuration defining an active diaphragm area with said cavity characterized in having steep sloped vertical walls formed by an anisotropic etching with the said walls aligned to the <111> plane of said monocrystalline semiconductor member, whereby said diaphragm exhibits a maximum response in only the longitudinal stress mode suitable for the use of piezoresistive elements operating in the longitudinal peizoresistive mode.
Claim 2
Dependent Claim
97 words
A diaphragm for a pressure transducer for use with piezoresistors comprising: a rectangular planar monocrystalline semiconductor member having a predetermined crystallographic orientation of (110), having located on a major surface thereof a cavity of a parallelogram configuration defining an active diaphragm area with said cavity characterized in having steep sloped vertical walls formed by an anisotropic etching with the said walls aligned to the <111> plane of said monocrystalline semiconductor member, whereby said diaphragm exhibits a maximum response in only the longitudinal stress mode suitable for the use of piezoresistive elements operating in the longitudinal peizoresistive mode.
Claim 3
Dependent Claim
24 words
The diaphragm according to claim 1 wherein said cavity has an aspect ratio (ratio of length to width) of greater than two to one.
Claim 4
Dependent Claim
24 words
The diaphragm according to claim 1 further comprising: at least one piezoresistor located on said planar member on the surface thereof above said cavity.
Claim 5
Dependent Claim
18 words
The diaphragm according to claim 1 wherein said parallelogram cavity has one acute and one obtuse base angle.
Claim 6
Dependent Claim
19 words
The diaphragm according to claim 4 wherein said actue angle is about 70°, and said obtuse angle about 110°.
Claim 7
Dependent Claim
25 words
The diaphragm according to claim 1 wherein said planar member has an aspect ratio (ratio of length to width) of greater than three to one.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-15 | 1986-05-17 | 1986-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-15 | 1990-05-17 | 1990-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-15 | 1994-05-17 | 1994-11-16 | $7700.00 | Window Closed / Lapsed |