US3624714A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoresistive miniature pressure transducer
Assignee: Dynasciences Corp
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Filing: 1970-04-23
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Granted: 1971-11-30
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Expires: 1990-04-23
Abstract
Abstract A miniature pressure transducer has an edge-supported flexible diaphragm with a semiconductor chip providing a bridge arrangement of the piezoresistive strain gauge areas bonded to its inner surface to position active tension gage areas at the center of the diaphragm and active compression gage areas at the periphery. The chip is also bonded along its outer periphery to the annular inner surface of the transducer body supporting the edges of the diaphragm to prevent slippage during deflection of the diaphragm, thus placing the effective compression gage areas of the chip outside of the neutral circle within the compression zone on the diaphragm.
Inventors
- 👤 James E Frassrand
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:50
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052; G01L9/0055
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
216 words
An improved pressure transducer comprising: an elOngated hollow transducer body having an internal bore coaxial with the axis of elongation of the body and a flat supporting end surface surrounding the opening at the end of said bore; an end closure member having a thin flexible flat wall extending across said end surface to cover the open end of said bore, said end closure member being bonded to said transducer body with opposing edges supported by said end surface to provide a central active diaphragm area corresponding to the dimensions of said bore; flat semiconductor means having active piezoresistive strain gauge areas defined therein bonded to the inner surface of said thin flexible wall with a pair of elongated tension gauge areas disposed parallel to one another adjacent to center of said diaphragm area and a pair of compression gauge areas being disposed partially within said active gauge area with a portion extending outwardly past said active diaphragm area between said end surface and the inner surface of said flat wall; and, adhesive means bonding said compression and tension gauge areas of said chip means to the inner surface of said flat wall and fixedly bonding said outwardly extending portion of said semiconductor means containing said compression gauge areas to said end surface to prevent slippage.
Claim 2
Dependent Claim
216 words
An improved pressure transducer comprising: an elOngated hollow transducer body having an internal bore coaxial with the axis of elongation of the body and a flat supporting end surface surrounding the opening at the end of said bore; an end closure member having a thin flexible flat wall extending across said end surface to cover the open end of said bore, said end closure member being bonded to said transducer body with opposing edges supported by said end surface to provide a central active diaphragm area corresponding to the dimensions of said bore; flat semiconductor means having active piezoresistive strain gauge areas defined therein bonded to the inner surface of said thin flexible wall with a pair of elongated tension gauge areas disposed parallel to one another adjacent to center of said diaphragm area and a pair of compression gauge areas being disposed partially within said active gauge area with a portion extending outwardly past said active diaphragm area between said end surface and the inner surface of said flat wall; and, adhesive means bonding said compression and tension gauge areas of said chip means to the inner surface of said flat wall and fixedly bonding said outwardly extending portion of said semiconductor means containing said compression gauge areas to said end surface to prevent slippage.
Claim 3
Dependent Claim
62 words
The improved pressure transducer in claim 1 wherein: said internal bore is cylindrical in shape, said flat supporting end surface is annular in shape surrounding said cylindrical internal bore, and said flat wall is disc-shaped to cover said annular end surface and the end of said bore to define a circular active diaphragm area corresponding to the inner dimensions of said bore.
Claim 4
Dependent Claim
77 words
The improved pressure transducer of claim 1 wherein: said semiconductor means comprises a single elongated silicon chip with active compression and tension gauge areas defined thereon in a bridge arrangement with intermediate contact areas, said compressive gauge areas each consisting of a U-shaped compressive gauge element formed at the opposite ends of said chip with the outer extremities of said U-shaped areas being bonded by said adhesive means to the abutting portions of said supporting end surface.
Claim 5
Dependent Claim
44 words
The improved pressure transducer of claim 1 wherein: said end closure means comprises a cup-shaped metal member with a bottom wall defining said flat thin wall containing said active diaphragm area and with sidewalls being bonded to the outer surfaces of said transducer body.
Claim 6
Dependent Claim
105 words
An improved pressure transducer comprising: diaphragm means having a thin flexible planar portion having an active diaphragm area, said diaphragm means having an outer pressure-receiving surface and an inner gauge-supporting surface; flat compression strain gauge means bonded to said inner surface at the periphery of said active diaphragm area with an outer edge portion extending outward past the periphery of said active diaphragm area; and, a body portion with edge support means having a flat end surface with the outer portion of said compression strain gauge means being fixedly bonded on opposite sides both to said inner gauge-supporting surface and to said flat end surface.
Claim 7
Dependent Claim
105 words
An improved pressure transducer comprising: diaphragm means having a thin flexible planar portion having an active diaphragm area, said diaphragm means having an outer pressure-receiving surface and an inner gauge-supporting surface; flat compression strain gauge means bonded to said inner surface at the periphery of said active diaphragm area with an outer edge portion extending outward past the periphery of said active diaphragm area; and, a body portion with edge support means having a flat end surface with the outer portion of said compression strain gauge means being fixedly bonded on opposite sides both to said inner gauge-supporting surface and to said flat end surface.
Claim 8
Dependent Claim
59 words
The improved pressure transducer of claim 5 further comprising: tension strain gauge means bonded to said inner gauge-supporting surface adjacent the center of said active diaphragm area; and, circuit means electrically connecting said tension and compression strain gauge means to produce mutually complementary output signals in response to a deflection of said diaphragm means within said active diaphragm area.
Claim 9
Dependent Claim
110 words
The improved pressure transducer of claim 6 wherein: said compression and tension strain gauge means constitute different narrow piezoresistive strips defined on a single flat semiconductive chip, said flat compression strain gauge means consisting of two piezoresistive active areas near the periphery of said chip and said tension strain gauge means constituting a pair of elongated paraLlel piezoresistive active areas adjacent the center of said active diaphragm area at the center of said chip; and, said connection means comprises low-resistance contact areas defined within said chip between the ends of said elongated piezoresistive active areas and the adjacent ends of said piezoresistive active areas constituting said compression strain gauge means.
Claim 10
Dependent Claim
37 words
The improved pressure transducer of claim 7 wherein: each of said piezoresistive active areas constituting said compression strain gauge means comprise narrow piezoresistive strips parallel to one another and connected in series by additional low-resistance contact areas.
Claim 11
Dependent Claim
66 words
The improved pressure transducer of claim 8 wherein: said flat end surface is bonded to the periphery of said chip at the outer extent of said piezoresistive strain gauge areas constituting said compression strain gauge mean so that said strain gauge mean is located within said active diaphragm area outside a neutral circle defined between compression and tension areas resulting from concave deflection of said diaphragm.
References Cited (Backward Citations)
US3434090A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |