Patent US4141253A successfully refreshed from Google Patents.
US4141253A
Expired / Lapsed
US
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Force transducing cantilever beam and pressure transducer incorporating it
Assignee: Honeywell Inc
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Filing: 1977-08-24
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Granted: 1979-02-27
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Expires: 1997-08-24
Abstract
Abstract The pressure transducer includes a semiconductor cantilever beam, a diaphragm, a spacer, and a back plate. The diaphragm, spacer, and back plate are bonded together at their peripheries to form a cup. The ends of the beam are bonded, respectively, to the supported periphery of the diaphragm and to an intermediate deflecting portion thereof, whereby pressure forces within the cup are transmitted by the diaphragm to the beam. Piezoresistive elements are diffused into the surface of the beam to produce an electric signal in accordance with the strain produced in the beam as the result of the pressure forces. In one embodiment, the beam is a flat plate. In another embodiment, the beam includes a portion at the mounting end that is massive relative to the stress sensitive portion of the beam. The juncture of the massive mounting portion and the stress sensitive portion is an abrupt step, whereby a precise fulcrum for the stress sensitive beam portion is provided. In another embodiment, a relatively massive beam portion also is provided at the movable end of the beam remote from the mounting end. Other embodiments include a wire or a spring inserted between the movable end of the beam and the deflecting portion of the diaphragm. The transducer materials and bonds are chosen to minimize hysteresis, which procedure includes making the internal viscosity of the diaphragm at least closely approach that of the beam.
Inventors
- 👤 Robert C. Whitehead, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:39
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/16; G01B7/18; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
198 words
A pressure transducer with minimized hysteresis, comprising a semiconductor beam having a stress sensitive portion, a diaphragm formed of a material having an internal viscosity which at least closely approaches that of said beam, supporting means for supporting said diaphragm at one portion thereof, pressurizing means for causing a fluid pressure to act on one surface of a deflecting portion of said diaphragm to cause the last mentioned portion to deflect with respect to said one portion by an amount dependent upon said pressure, mounting means for mounting one end of said beam on said supporting means to cantilever said beam from said supporting means, connecting means for connecting the other end of said beam to said deflecting portion of said diaphragm to cause said other end to be deflected by deflection of said deflecting portion, said mounting means and said connecting means being constructed and arranged to preserve the unitary internal viscosity of said beam and said diaphragm within said transducer to minimize the hysteresis exhibited thereby, and a semiconductor strain gauge diffused into the surface of said stress sensitive portion to sense the strain produced therein by the deflection of said other end of said beam.
Claim 2
Dependent Claim
198 words
A pressure transducer with minimized hysteresis, comprising a semiconductor beam having a stress sensitive portion, a diaphragm formed of a material having an internal viscosity which at least closely approaches that of said beam, supporting means for supporting said diaphragm at one portion thereof, pressurizing means for causing a fluid pressure to act on one surface of a deflecting portion of said diaphragm to cause the last mentioned portion to deflect with respect to said one portion by an amount dependent upon said pressure, mounting means for mounting one end of said beam on said supporting means to cantilever said beam from said supporting means, connecting means for connecting the other end of said beam to said deflecting portion of said diaphragm to cause said other end to be deflected by deflection of said deflecting portion, said mounting means and said connecting means being constructed and arranged to preserve the unitary internal viscosity of said beam and said diaphragm within said transducer to minimize the hysteresis exhibited thereby, and a semiconductor strain gauge diffused into the surface of said stress sensitive portion to sense the strain produced therein by the deflection of said other end of said beam.
Claim 3
Dependent Claim
73 words
A transducer as specified in claim 1, wherein said diaphragm is of circular configuration, said one portion of said diaphragm is the periphery thereof, said deflecting portion of said diaphragm is the remainder thereof, said mounting means mounts said one end of said beam on said supporting means at the periphery of said diaphragm, and said connecting means connects said other end of said beam to said diaphragm at substantially the center thereof.
Claim 4
Dependent Claim
95 words
A transducer as specified in claim 2, wherein said supporting means includes a spacer and a back plate bonded together at their peripheries with said periphery of said diaphragm to form a cup, said spacer and said back plate have an internal viscosity which at least closely approaches that of said diaphragm and said beam, said cup is filled with a fluid which contacts said surface of said diaphragm, and said pressurizing means includes a fluid connection into said cup to transmit said fluid pressure to said fluid and to said surface of said diaphragm.
Claim 5
Dependent Claim
35 words
A transducer as specified in claim 3, wherein said diaphragm, said spacer, and said back plate are formed of glass, quartz, silicon, or a combination thereof, and wherein said bonding is gold eutectic or electrostatic.
Claim 6
Dependent Claim
13 words
A transducer as specified in claim 1, wherein said semiconductor material is silicon.
Claim 7
Dependent Claim
71 words
A transducer as specified in claim 1, wherein said beam has a mounting portion at said one end which is massive relative to said stress sensitive portion and which provides an abrupt step at the juncture of said mounting portion and said stress sensitive portion, and said mounting means mounts said mounting portion on said supporting means to cause said juncture to provide a precise fulcrum for said stress sensitive portion.
Claim 8
Dependent Claim
37 words
A transducer as specified in claim 6, wherein said beam has a terminating portion at said other end which is massive relative to said stress sensitive portion, and said terminating portion is included in said connecting means.
Claim 9
Dependent Claim
21 words
A transducer as specified in claim 7, wherein said beam is a unitary beam fabricated from a single block of material.
Claim 10
Dependent Claim
21 words
A transducer as specified in claim 6, wherein said beam is a unitary beam fabricated from a single block of material.
Claim 11
Dependent Claim
19 words
A transducer as specified in claim 1, wherein said beam is formed of a single crystal of semiconductor material.
Claim 12
Dependent Claim
37 words
A transducer as specified in claim 1, wherein said beam has a terminating portion at said other end which is massive relative to said stress sensitive portion, and said terminating portion is included in said connecting means.
Claim 13
Dependent Claim
21 words
A transducer as specified in claim 11, wherein said beam is a unitary beam fabricated from a single block of material.
Claim 14
Dependent Claim
50 words
A transducer as specified in claim 1, wherein said connecting means includes a wire through which said deflecting portion of said diaphragm deflects said other end of said beam, the material of said wire having an internal viscosity which at least closely approaches that of said diaphragm and said beam.
Claim 15
Dependent Claim
50 words
A transducer as specified in claim 1, wherein said connecting means includes a spring through which said deflecting portion of said diaphragm deflects said other end of said beam, the material of said spring having an internal viscosity which at least closely approaches that of said diaphragm and said beam.
Claim 16
Dependent Claim
49 words
A transducer as specified in claim 1, wherein said mounting means is a bond between said one end of said beam and said one portion of said diaphragm, and said connecting means is a bond between said other end of said beam and said deflecting portion of said diaphragm.
Claim 17
Dependent Claim
16 words
A transducer as specified in claim 15, wherein said bonds are gold eutectic or electrostatic bonds.
Claim 18
Dependent Claim
19 words
A transducer as specified in claim 16, wherein said diaphragm material is glass, quartz, silicon, or a combination thereof.
Claim 19
Dependent Claim
19 words
A transducer as specified in claim 1, wherein said diaphragm material is glass, quartz, silicon, or a combination, thereof.
Claim 20
Dependent Claim
93 words
A transducer, comprising a unitary beam fabricated from a single block of material and having a mounting portion at one end and a stress sensitive portion extending from said mounting portion, the latter being massive relative to said stress sensitive portion and providing an abrupt step at the juncture of said portions which constitutes a precise fulcrum for said stress sensitive portion, and sensing means disposed in association with said stress sensitive portion to sense strain induced therein as the result of the application of force to the other end of said beam.
Claim 21
Dependent Claim
93 words
A transducer, comprising a unitary beam fabricated from a single block of material and having a mounting portion at one end and a stress sensitive portion extending from said mounting portion, the latter being massive relative to said stress sensitive portion and providing an abrupt step at the juncture of said portions which constitutes a precise fulcrum for said stress sensitive portion, and sensing means disposed in association with said stress sensitive portion to sense strain induced therein as the result of the application of force to the other end of said beam.
Claim 22
Dependent Claim
19 words
A transducer as specified in claim 19, wherein said beam is formed of a single crystal of semiconductor material.
Claim 23
Dependent Claim
25 words
A transducer as specified in claim 20, wherein said sensing means includes a semiconductor strain gauge diffused into the surface of said stress sensitive portion.
Claim 24
Dependent Claim
38 words
A transducer as specified in claim 19, wherein said beam has a terminating portion at said other end which is massive relative to said stress sensitive portion and which facilitates said application of force to said other end.
Claim 25
Dependent Claim
19 words
A transducer as specified in claim 22, wherein said beam is formed of a single crystal of semiconductor material.
Claim 26
Dependent Claim
25 words
A transducer as specified in claim 23, wherein said sensing means includes a semiconductor strain gauge diffused into the surface of said stress sensitive portion.
Claim 27
Dependent Claim
77 words
A transducer, comprising a unitary beam fabricated from a single block of material and having one end arranged to be supported, having a terminating portion at its other end, and having a stress sensitive portion between said ends, said terminating portion being massive relative to said stress sensitive portion, and sensing means disposed in association with said stress sensitive portion to sense strain induced therein as a result of the application of force to said terminating portion.
Claim 28
Dependent Claim
77 words
A transducer, comprising a unitary beam fabricated from a single block of material and having one end arranged to be supported, having a terminating portion at its other end, and having a stress sensitive portion between said ends, said terminating portion being massive relative to said stress sensitive portion, and sensing means disposed in association with said stress sensitive portion to sense strain induced therein as a result of the application of force to said terminating portion.
Claim 29
Dependent Claim
19 words
A transducer as specified in claim 25, wherein said beam is formed of a single crystal of semiconductor material.
Claim 30
Dependent Claim
25 words
A transducer as specified in claim 26, wherein said sensing means includes a semiconductor strain gauge diffused into the surface of said stress sensitive portion.
Claim 31
Dependent Claim
187 words
A pressure transducer with minimized hysteresis, comprising a semiconductor beam having first and second ends, a diaphragm having a periphery by which said diaphragm is supported, having a central portion which is arranged to be deflected with respect to said periphery by an amount dependent upon the pressure of a fluid acting on a surface of said central portion, and formed of a material having an internal viscosity which at least closely approaches that of said beam and which, when bonded to said beam, forms therewith a structure exhibiting a minimum of hysteresis, a bond bonding said first end of said beam to said supported periphery of said diaphragm to cantilever said beam from said first end thereof, a bond bonding said second end of said beam to said central portion of said diaphragm for deflection of said second end with respect to said first end in accordance with said deflection of said central portion, and a semiconductor strain gauge diffused into the surface of said beam between said first and second ends thereof to sense said deflection of said second end and hence said fluid pressure.
Claim 32
Dependent Claim
187 words
A pressure transducer with minimized hysteresis, comprising a semiconductor beam having first and second ends, a diaphragm having a periphery by which said diaphragm is supported, having a central portion which is arranged to be deflected with respect to said periphery by an amount dependent upon the pressure of a fluid acting on a surface of said central portion, and formed of a material having an internal viscosity which at least closely approaches that of said beam and which, when bonded to said beam, forms therewith a structure exhibiting a minimum of hysteresis, a bond bonding said first end of said beam to said supported periphery of said diaphragm to cantilever said beam from said first end thereof, a bond bonding said second end of said beam to said central portion of said diaphragm for deflection of said second end with respect to said first end in accordance with said deflection of said central portion, and a semiconductor strain gauge diffused into the surface of said beam between said first and second ends thereof to sense said deflection of said second end and hence said fluid pressure.
References Cited (Backward Citations)
US3780588A
Cited
US4023562A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-26 | 1982-08-28 | 1983-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-26 | 1986-08-28 | 1987-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-26 | 1990-08-28 | 1991-02-27 | $7700.00 | Window Closed / Lapsed |