Patent US3819431A successfully refreshed from Google Patents.
US3819431A
Expired / Lapsed
US
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Method of making transducers employing integral protective coatings and supports
Assignee: Kulite Semiconductor Products Inc
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Filing: 1972-12-07
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Granted: 1974-06-25
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Expires: 1992-12-07
Abstract
Abstract There is disclosed a force transducer fabricated from silicon and having the appearance of an annular disk. Disposed on one surface of said disk are one or more piezoresistive elements which respond to a force applied to a diaphragm portion of said disk which is surrounded by the wall formed by the annular ring. The disk is mounted in a housing with the piezoresistive elements facing away from the applied force surface; this surface of the diaphragm and ring has formed thereon a thin layer of silicon dioxide which serves to protect the disk against deleterious agents present in the force transmitting environment while further serving to eliminate an undesirable bimetallic effect.
Inventors
- 👤 A Kurtz
- 👤 C Gravel
- 👤 J Hallon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:50
CPC Classifications
H; H10; H10D; H10D48/00; H10D48/50; G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052; G01L9/0055; Y; Y10; Y10S; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
20 words
The method according to claim 1 wherein said thin layer of silicon dioxide is between 1,000 and 30,000 Angstrom units.
Claim 2
Dependent Claim
16 words
The method according to claim 1 wherein said predetermined thickness is between 0.1 to 1 mil.
Claim 3
Dependent Claim
19 words
The method according to claim 1 wherein said thick layer of polycrystalline silicon is between 1 to 10 mils.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |