US3924322A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Economical pressure transducer assemblies, methods of fabricating and mounting the same
Assignee: Kulite Semiconductor Products Inc
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Filing: 1975-01-27
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Granted: 1975-12-09
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Expires: 1995-01-27
Abstract
Abstract There is disclosed apparatus to provide a low cost transducer which may be conveniently mounted in a transistor or I.C. header while capable of giving accurate measurements in the presence of extraneous disturbances. An oxide layer is grown over a piezoresistor pattern, the layer is opened and contacts are deposited. Depressions are etched beneath the pattern to form individual cups for the plurality of patterns. The slice as etched is sealed to a glass sheet which serves to close the bottom of the cup. The glass is then sealed to a thick slice of silicon which serves as an attenuator to isolate the transducer from insignificant perturbations. The unit is then mounted within a TO-5 can or flat pack header with the piezoresistive pattern facing upwards or exposed.
Inventors
- 👤 Anthony D Kurtz
- 👤 Amnon Brosh
- 👤 Charles L Gravel
- 👤 Joseph R Mallon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:08
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052; G01L9/0054; G01L9/0042; H; H10; H10D; H10D48/00; H10D48/50
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
176 words
A method of fabricating a pressure transducer comprising the steps of: a. diffusing a plurality of piezoresistive bridge patterns on a given surface of a first wafer of semiconductor material, b. coating said diffused surface with a layer of semiconductor oxide material, c. forming apertures in said layer to contact each of said patterns, d. metalizing said apertures to form a series of metal contact areas on said surface of said layer, e. forming a series of apertures on the opposite side of said wafer and beneath each of said patterns to define an active diaphragm area, f. bonding said wafer at said opposite side to a layer of an insulator material to close each of said apertures formed on the opposite side of said wafer, g. bonding said opposite side of said glass layer to a thicker wafer of semiconductor material to act as an attenuator for said transducEr, and h. separating each of said patterns together with all bonded members to provide a given number of separate pressure transducers structures equal to said plurality.
Claim 2
Independent Claim
176 words
A method of fabricating a pressure transducer comprising the steps of: a. diffusing a plurality of piezoresistive bridge patterns on a given surface of a first wafer of semiconductor material, b. coating said diffused surface with a layer of semiconductor oxide material, c. forming apertures in said layer to contact each of said patterns, d. metalizing said apertures to form a series of metal contact areas on said surface of said layer, e. forming a series of apertures on the opposite side of said wafer and beneath each of said patterns to define an active diaphragm area, f. bonding said wafer at said opposite side to a layer of an insulator material to close each of said apertures formed on the opposite side of said wafer, g. bonding said opposite side of said glass layer to a thicker wafer of semiconductor material to act as an attenuator for said transducEr, and h. separating each of said patterns together with all bonded members to provide a given number of separate pressure transducers structures equal to said plurality.
Claim 3
Dependent Claim
19 words
The method according to claim 1 wherein: a. said first wafer of semiconductor material is n-type single, crystal silicon.
Claim 4
Dependent Claim
17 words
The method according to claim 2 wherein: a. said layer of semiconductor oxide material is silicon dioxide.
Claim 5
Dependent Claim
15 words
The method according to claim 1 wherein said metal contact areas are formed from platinum.
Claim 6
Dependent Claim
14 words
The method according to claim 1 wherein said layer of insulator material is glass.
Claim 7
Dependent Claim
15 words
The method according to claim 1 wherein said thicker wafer of semiconductor material is silicon.
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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |