Patent US4675643A successfully refreshed from Google Patents.
US4675643A
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US
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Pressure transducer utilizing a transduction element
Assignee: Kristal Instrumente AG
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Filing: 1984-08-29
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Granted: 1987-06-23
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Expires: 2004-08-29
Abstract
Abstract A piezoresistive transduction element for incorporation into a pressure transducer includes a plate defining a diaphragm zone and preferably of silicon with piezoresistances diffused into it, an insulating plate of a glass material and a base plate. The plates are preferably connected to each other by anodic connections in a series of steps. The base plate is made of a material having substantially the same coefficient of thermal expansion as that of the material of the plate which defines the diaphragm zone. Furthermore, the dimensions of the base plate are matched to those of the diaphragm plate. By these measures the deformation forces exerted by the base plate and diaphragm plate on the insulating plate upon changes in temperature are of substantially the same magnitude and therefore there is minimum bending of the diaphragm plate. A symmetrical transduction element is created which has minimum zero point displacement and minimum sensitivity changes in use. Pressure transducers equipped with such piezoresistive transduction elements are therefore appropriate for high measuring accuracy, particularly in combination with an improved, elastically extensible securement of a holder which carries the transduction element within the transducer housing.
Inventors
- 👤 Rene Tanner
- 👤 Reto Calderara
- 👤 Alfred Wenger
- 👤 Hans-Conrad Sonderegger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:36
CPC Classifications
G; G01; G01L; G01L19/00; G01L19/0061; G01L19/0084; G01L19/06; G01L19/0627; G01L19/0645; G01L19/14; G01L19/147
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
115 words
A transduction element comprising a diaphram plate defining at least one diaphragm zone and made of semiconductor material having at least one piezoresistance, an insulating plate to which said diaphragm plate is secured, and a base plate secured to the surface of the insulating plate remote from the diaphragm plate, the material and dimensions of said base plate being balanced in relation to the diaphragm plate so that with temperature changes the deformation forces exerted by the diaphragm plate and the base plate on the insulating plate are substantially equal, said materials of the base plate and diaphragm plate having substantially equal coefficients of thermal expansion, whereby the transduction element has a symmetrical stress status.
Claim 2
Dependent Claim
115 words
A transduction element comprising a diaphram plate defining at least one diaphragm zone and made of semiconductor material having at least one piezoresistance, an insulating plate to which said diaphragm plate is secured, and a base plate secured to the surface of the insulating plate remote from the diaphragm plate, the material and dimensions of said base plate being balanced in relation to the diaphragm plate so that with temperature changes the deformation forces exerted by the diaphragm plate and the base plate on the insulating plate are substantially equal, said materials of the base plate and diaphragm plate having substantially equal coefficients of thermal expansion, whereby the transduction element has a symmetrical stress status.
Claim 3
Dependent Claim
22 words
A transduction element as claimed in claim 1, wherein the base plate and the diaphragm plate are made of the same material.
Claim 4
Dependent Claim
21 words
A transduction element as claimed in claim 1, wherein the base plate and the diaphragm plate are made of different materials.
Claim 5
Dependent Claim
25 words
A transduction element as claimed in claim 2, wherein the diaphragm plate and the base plate are made of silicon material, especially from monocrystal silicon.
Claim 6
Dependent Claim
21 words
A transduction element as claimed in claim 3, wherein the diaphragm plate is made of silicon material, especially from monocrystal silicon.
Claim 7
Dependent Claim
18 words
A transduction element as claimed in claim 1, wherein the insulating plate is made of a glass material.
Claim 8
Dependent Claim
35 words
A transduction element as claimed in claim 1, wherein there is an anodic connection between the diaphragm plate and the insulating plate and a glass frit connection between the insulating plate and the base plate.
Claim 9
Dependent Claim
45 words
A transduction element as claimed in claim 1, wherein there is an anodic connection between the diaphragm plate and the insulating plate and simultaneously applied glass frit connections between the insulating plate and the base plate and between the base plate and an intermediate support.
Claim 10
Dependent Claim
22 words
A transduction element as claimed in claim 1, having anodic connections between the diaphragm plate, the insulating plate and the base plate.
Claim 11
Dependent Claim
37 words
A transduction element as claimed in claim 1, including an intermediate support which is secured to the base plate and is made of a material having substantially the same coefficient of thermal expansion as the insulating plate.
Claim 12
Dependent Claim
38 words
A transduction element as claimed in claim 1, adapted for relative pressure measurements, having at least one hole extending through the base plate and the insulating plate in the direction towards the diaphragm zone of the diaphragm plate.
Claim 13
Dependent Claim
128 words
A pressure transducer incorporating a transduction element, comprising a plate defining at least one diaphragm zone and made of semiconductor material having at least one piezoresistance, an insulating plate to which the diaphragm plate is secured, and a base plate secured to the surface of the insulating plate remote from the diaphragm plate, the material and dimensions of said base plate being balanced in relation to the diaphragm plate so that with temperature changes the deformation forces exerted by the diaphragm plate and the base plate on the insulating plate are substantially equal, whereby the transduction element has a symmetrical stress status, said transduction element being secured directly, or by means of an intermediate support secured to the base plate, onto a holder arranged in the transducer housing.
Claim 14
Dependent Claim
128 words
A pressure transducer incorporating a transduction element, comprising a plate defining at least one diaphragm zone and made of semiconductor material having at least one piezoresistance, an insulating plate to which the diaphragm plate is secured, and a base plate secured to the surface of the insulating plate remote from the diaphragm plate, the material and dimensions of said base plate being balanced in relation to the diaphragm plate so that with temperature changes the deformation forces exerted by the diaphragm plate and the base plate on the insulating plate are substantially equal, whereby the transduction element has a symmetrical stress status, said transduction element being secured directly, or by means of an intermediate support secured to the base plate, onto a holder arranged in the transducer housing.
Claim 15
Dependent Claim
26 words
A pressure transducer as claimed in claim 12, in which the holder is substantially plate-like and connected in an elastically extensible manner to the transducer housing.
Claim 16
Dependent Claim
25 words
A pressure transducer as claimed in claim 13, in which the holder is connected to the transducer housing by means of a tubular holder portion.
Claim 17
Dependent Claim
26 words
A pressure transducer as claimed in claim 14, in which the tubular holder portion extends from the same side of the holder as the transduction element.
Claim 18
Dependent Claim
31 words
A pressure transducer as claimed in claim 13, in which the tubular holder portion extends from the side of the holder opposite to that at which the transducer element is located.
Claim 19
Dependent Claim
30 words
A pressure transducer as claimed in claim 13, in which a pressure transmission medium is hermetically sealed into the transducer by a diaphragm for pressure loading of the transduction element.
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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) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |