Patent US6676627B1 successfully refreshed from Google Patents.
US4016644A
Expired / Lapsed
US
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Methods of fabricating low pressure silicon transducers
Assignee: Kulite Semiconductor Products Inc
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Filing: 1976-01-14
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Granted: 1977-04-12
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Expires: 1996-01-14
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
2026-10-23 20:15
CPC Classifications
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; Y; Y10; Y10S; Y10S148/00; Y10S148/028; Y10S148/135; Y10T; Y10T29/00; Y10T29/42; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49103
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
112 words
The method of fabricating a transducer comprising the steps of: a. diffusing a plurality of piezoresistive patterns on a surface of a single n-type silicon wafer, b. bonding a thin glass sheet to the surface of said wafer opposite to that surface upon which said patterns are diffused, c. separating each of said patterns to form a plurality of individual patterns, and d. glass bonding each individual pattern on a separate diaphragm of silicon, of non-critical electrical properties as compared to said n-type wafer to form a plurality of separate diaphragm transducer structures, whereby said portion of said glass sheet on said individual pattern is bonded to said separate diaphragm of silicon.
Claim 2
Independent Claim
112 words
The method of fabricating a transducer comprising the steps of: a. diffusing a plurality of piezoresistive patterns on a surface of a single n-type silicon wafer, b. bonding a thin glass sheet to the surface of said wafer opposite to that surface upon which said patterns are diffused, c. separating each of said patterns to form a plurality of individual patterns, and d. glass bonding each individual pattern on a separate diaphragm of silicon, of non-critical electrical properties as compared to said n-type wafer to form a plurality of separate diaphragm transducer structures, whereby said portion of said glass sheet on said individual pattern is bonded to said separate diaphragm of silicon.
Claim 3
Dependent Claim
35 words
The method according to claim 1 furhter comprising the step of: a. etching an aperture in said separate silicon diaphragm prior to bonding said pattern and thence bonding said individual pattern within said etched aperture.
Claim 4
Independent Claim
137 words
The method of fabricating a transducer, comprising the steps of: a. diffusing a plurality of piezoresistor bridge patterns on a surface of an n-type first wafer of silicon. b. bonding a thin glass sheet to the surface of the first wafer opposite to that surface upon which said patterns are diffused, c. scribing each of said patterns to form a plurality of individual bridge cells, d. cutting a plurality of diaphragms of desired thicknesses from a second wafer of silicon of non-critical electrical properties as compared to said first wafer, e. glass bonding a separate one of said cells to a separate one of said diaphragms to form a plurality of separate transducers each including a cell and a diaphragm, whereby said portion of said glass sheets associated with said cell is bonded to said separate diaphragm.
Claim 5
Independent Claim
137 words
The method of fabricating a transducer, comprising the steps of: a. diffusing a plurality of piezoresistor bridge patterns on a surface of an n-type first wafer of silicon. b. bonding a thin glass sheet to the surface of the first wafer opposite to that surface upon which said patterns are diffused, c. scribing each of said patterns to form a plurality of individual bridge cells, d. cutting a plurality of diaphragms of desired thicknesses from a second wafer of silicon of non-critical electrical properties as compared to said first wafer, e. glass bonding a separate one of said cells to a separate one of said diaphragms to form a plurality of separate transducers each including a cell and a diaphragm, whereby said portion of said glass sheets associated with said cell is bonded to said separate diaphragm.
Claim 6
Dependent Claim
47 words
The method according to claim 1 wherein said bonding steps are accomplished by holding said parts to be bonded in intimate contact under elevated pressure and temperature and applying a potential therebetween to cause ions to move from one part to the other to provide said bond.
Claim 7
Dependent Claim
15 words
The method according to claim 1 wherein said thin glass sheet is a borosilicate glass.
Claim 8
Dependent Claim
37 words
The method according to claim 1 further comprising the steps of: a. forming an aperture on said diaphragm and thence bonding a separate one of said cells to a separate one of said diaphragms within said aperture.
Claim 9
Dependent Claim
18 words
The method according to claim 6 wherein said aperture is formed near the outer edge of said diaphragm.
Claim 10
Dependent Claim
17 words
The method according to claim 6 wherein said diaphragm is approximately one-half inch in diameter or greater.
Claim 11
Independent Claim
172 words
A method of fabricating a low pressure transducer comprising the steps of: a. diffusing a plurality of piezoresistive elements on a surface of a first wafer of silicon; said silicon being of the (110) plane n-type conductivity, b. polishing the opposite surface of said wafer of silicon to provide a smooth surface opposite to said surface containing said elements, c. bonding a sheet of glass to said smooth surface to provide a composite assembly, d. scribing said composite assembly to provide a plurality of individual elements from said composite assembly, e. cutting a plurality of diaphragms from a cylindrical second wafer of silicon of a single crystal structure and of non-critical electrical properties as compared to said first wafer and each diaphragm of a diameter equal to the diameter of said cylinder and said diameter larger than any individual element, f. glass bonding a separate one of said elements to a separate one of said diaphragms to provide a transducer, by employing the portion of said glass sheet as the bonding agent.
Claim 12
Independent Claim
172 words
A method of fabricating a low pressure transducer comprising the steps of: a. diffusing a plurality of piezoresistive elements on a surface of a first wafer of silicon; said silicon being of the (110) plane n-type conductivity, b. polishing the opposite surface of said wafer of silicon to provide a smooth surface opposite to said surface containing said elements, c. bonding a sheet of glass to said smooth surface to provide a composite assembly, d. scribing said composite assembly to provide a plurality of individual elements from said composite assembly, e. cutting a plurality of diaphragms from a cylindrical second wafer of silicon of a single crystal structure and of non-critical electrical properties as compared to said first wafer and each diaphragm of a diameter equal to the diameter of said cylinder and said diameter larger than any individual element, f. glass bonding a separate one of said elements to a separate one of said diaphragms to provide a transducer, by employing the portion of said glass sheet as the bonding agent.
Claim 13
Dependent Claim
33 words
The method according to claim 9 further comprising the step of: forming an aperture in each of said diaphragms of a dimension to accommodate said element and bonding said element within said aperture.
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) | 1980-04-11 | 1980-10-11 | 1981-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-11 | 1984-10-11 | 1985-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-11 | 1988-10-11 | 1989-04-12 | $7700.00 | Window Closed / Lapsed |