Patent US4025942A successfully refreshed from Google Patents.
US4025942A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low pressure transducers employing large silicon diaphragms having non-critical electrical properties
Assignee: Kulite Semiconductor Products Inc
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Filing: 1976-05-05
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Granted: 1977-05-24
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Expires: 1996-05-05
Abstract
Abstract A low pressure transducer and methods of fabricating the same employ piezoresistive bridges deposited on or diffused within a wafer of n-type silicon, the wafer is secured to a glass sheet and is then bonded to a silicon diaphragm of a relatively large size and fabricated from a distinct piece of silicon of non-critical electrical characteristics. Methods for producing a plurality of such devices by using compatible processing steps are also provided.
Inventors
- 👤 Anthony D. Kurtz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:37
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0042; H; H10; H10D; H10D48/00; H10D48/50; H10P; H10P54/00; H10W; H10W72/00; H10W72/071; H10W72/073; H10W72/07331; H10W72/07336; H10W72/07337; H10W72/30; H10W72/351; H10W72/353; H10W72/354; H10W72/50; H10W72/551; H10W72/552; H10W72/5522; H10W72/851; H10W72/874; H10W72/884; H10W90/00; H10W90/701; H10W90/751; H10W90/754
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
119 words
A pressure transducer for pressure measurements of about 15 psi or less, comprising: (a) a wafer of n-type silicon having a top surface and a relatively smooth bottom surface, (b) a piezoresistor diffused into said top surface of said n-type silicon wafer, (c) a silicon diaphragm fabricated from a separate and distinct piece of silicon of non-critical electrical properties as compared to said wafer, said diaphragm being much larger than said wafer, (d) means bonding said wafer at said bottom surface at a position on said diaphragm removed from said center, said means including a glass bond, and (e) housing means coupled to said diaphragm about the outer periphery thereof to position the same in a pressure sensing mode.
Claim 2
Dependent Claim
119 words
A pressure transducer for pressure measurements of about 15 psi or less, comprising: (a) a wafer of n-type silicon having a top surface and a relatively smooth bottom surface, (b) a piezoresistor diffused into said top surface of said n-type silicon wafer, (c) a silicon diaphragm fabricated from a separate and distinct piece of silicon of non-critical electrical properties as compared to said wafer, said diaphragm being much larger than said wafer, (d) means bonding said wafer at said bottom surface at a position on said diaphragm removed from said center, said means including a glass bond, and (e) housing means coupled to said diaphragm about the outer periphery thereof to position the same in a pressure sensing mode.
Claim 3
Dependent Claim
21 words
The transducer according to claim 1 wherein said means bonding said wafer is a glass bond formed by a diffusion process.
Claim 4
Dependent Claim
23 words
The transducer according to claim 1 wherein said piezoresistive element is a Wheatstone bridge configuration comprising four piezoresistors arranged in the <110> directions.
Claim 5
Dependent Claim
18 words
The transducer according to claim 1 wherein said silicon diaphragm has a diameter of at least one-half inch.
Claim 6
Dependent Claim
14 words
The transducer according to claim 1 wherein said housing is fabricated from a metal.
Claim 7
Dependent Claim
103 words
A pressure transducer for pressure measurements relatively about 15 psi or less, comprising a wafer of single crystal silicon of a given and specified conductivity having diffused on a surface thereof a piezoresistor bridge pattern, said opposite surface of said wafer being relatively smooth, a silicon diaphragm of a size much larger than said wafer and fabricated from a distinct piece of silicon of non-critical electrical properties compared to said wafer and having a smooth, complemental surface to said opposite surface of said wafer, said complemental surface including a depression for accommodating said wafer, and means for bonding said wafer within said depression.
Claim 8
Dependent Claim
103 words
A pressure transducer for pressure measurements relatively about 15 psi or less, comprising a wafer of single crystal silicon of a given and specified conductivity having diffused on a surface thereof a piezoresistor bridge pattern, said opposite surface of said wafer being relatively smooth, a silicon diaphragm of a size much larger than said wafer and fabricated from a distinct piece of silicon of non-critical electrical properties compared to said wafer and having a smooth, complemental surface to said opposite surface of said wafer, said complemental surface including a depression for accommodating said wafer, and means for bonding said wafer within said depression.
Claim 9
Dependent Claim
109 words
A pressure transducer for pressure measurements relatively about 15 psi or less, comprising a bridge pattern fabricated from a contiguous piece of silicon of a given and specified conductivity, a diaphragm member of a size much larger than said pattern, fabricated from a piece of silicon of different non-critical electrical characteristics from said contiguous piece and of the type not adapted to accommodate diffusion of bridge patterns, having a smooth surface for accommodating said bridge pattern and means securing said pattern to said diaphragm, said means including a bond fabricated from the transportation of ions between media due to said means to secure said pattern to said diaphragm member.
Claim 10
Dependent Claim
109 words
A pressure transducer for pressure measurements relatively about 15 psi or less, comprising a bridge pattern fabricated from a contiguous piece of silicon of a given and specified conductivity, a diaphragm member of a size much larger than said pattern, fabricated from a piece of silicon of different non-critical electrical characteristics from said contiguous piece and of the type not adapted to accommodate diffusion of bridge patterns, having a smooth surface for accommodating said bridge pattern and means securing said pattern to said diaphragm, said means including a bond fabricated from the transportation of ions between media due to said means to secure said pattern to said diaphragm member.
Claim 11
Dependent Claim
15 words
The pressure transducer according to claim 7 wherein said means includes a glass bonding means.
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) | 1980-05-23 | 1980-11-22 | 1981-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-23 | 1984-11-22 | 1985-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-23 | 1988-11-22 | 1989-05-24 | $7700.00 | Window Closed / Lapsed |