US4987781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Accelerometer chip
Assignee: Honeywell International Inc
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Filing: 1989-05-03
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Granted: 1991-01-29
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Expires: 2009-05-03
Abstract
Abstract A silicon accelerometer chip has a seismic mass (which is a gold sphere) fixed in a cavity formed in a boss supported by beams. Pizeo-resistors forming a Wheatstone bridge are formed in the beams. The cavity is formed by anisotroptically etching the boss, so that the cavity is self-aligned to the sphere.
Inventors
- 👤 Hans Reimann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:33
CPC Classifications
G; G01; G01P; G01P21/00; G01P15/00; G01P15/02; G01P15/08; G01P15/12; G01P15/123
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
48 words
A semiconductor chip accelerometer comprising: a semiconductor substrate; resistance means formed in the semiconductor substrate for providing an electric resistance as a function of force on the substrate; a cavity defined by the substrate; and a body fixed in the cavity for exerting a force on the substrate.
Claim 2
Dependent Claim
48 words
A semiconductor chip accelerometer comprising: a semiconductor substrate; resistance means formed in the semiconductor substrate for providing an electric resistance as a function of force on the substrate; a cavity defined by the substrate; and a body fixed in the cavity for exerting a force on the substrate.
Claim 3
Dependent Claim
13 words
The claim of claim 1 wherein the body is substantially spherical in shape.
Claim 4
Dependent Claim
13 words
The device of claim 1 wherein the body is substantially comprised of gold.
Claim 5
Dependent Claim
12 words
The device of claim 1 wherein the cavity is substantially obelisk shaped.
Claim 6
Dependent Claim
24 words
The device of claim 4 wherein the cavity has sidewalls having an angle of about 54.7 degrees to a principal surface of the substrate.
Claim 7
Dependent Claim
15 words
The device of claim 5 wherein the body is bonded to the sidewalls by epoxy.
Claim 8
Dependent Claim
16 words
The device of claim 5 wherein the body is bonded to the sidewalls by a eutectic.
Claim 9
Dependent Claim
35 words
The device of claim 5, further comprising a cover affixed to the principal surface of the substrate and including deflection stops formed in the cover to limit movement of a portion of the principal surface.
Claim 10
Dependent Claim
22 words
The device of claim 1 wherein the resistance means comprises ion-implanted resistors formed in beams bridging a gap defined by the substrate.
Claim 11
Dependent Claim
12 words
The device of claim 9 wherein the resistors form a Wheatstone bridge.
Claim 12
Dependent Claim
14 words
The device of claim 1 wherein the substrate comprises silicon having a <100> orientation.
Claim 13
Dependent Claim
34 words
The device of claim 1, wherein the body comprises a magnetically susceptible material; and, further comprising an inductor located in juxtaposition to the body, wherein the body is movable upon operation of the inductor.
Claim 14
Independent Claim
48 words
A method for forming a semiconductor accelerometer chip comprising the steps of: providing a substrate; forming resistors in the substrate, the resistors having a resistance which is a function of a deformation of the substrate; forming a cavity in the substrate; and fixing a body in the cavity.
Claim 15
Independent Claim
48 words
A method for forming a semiconductor accelerometer chip comprising the steps of: providing a substrate; forming resistors in the substrate, the resistors having a resistance which is a function of a deformation of the substrate; forming a cavity in the substrate; and fixing a body in the cavity.
Claim 16
Dependent Claim
22 words
The method of claim 13, further comprising the step of forming the resistors in a beam spanning a gap in the substrate.
Claim 17
Dependent Claim
23 words
The method of claim 13, wherein the step of forming the cavity comprises the step of anisotropically etching the cavity in the substrate.
Claim 18
Dependent Claim
17 words
The method of claim 13, wherein the body is substantially spherical and is substantially comprised of gold.
Claim 19
Dependent Claim
74 words
A semiconductor accelerometer chip comprising: a semiconductor substrate; resistance means formed in the semiconductor substrate for providing an electric resistance as a function of force on the substrate; a cavity defined by the substrate; a magnetically susceptible body fixed in the cavity for exerting a force on the substrate; and an inductor located in juxtaposition to the magnetically susceptible body, wherein the body is movable upon operation of the inductor thereby moving the substrate.
Claim 20
Dependent Claim
74 words
A semiconductor accelerometer chip comprising: a semiconductor substrate; resistance means formed in the semiconductor substrate for providing an electric resistance as a function of force on the substrate; a cavity defined by the substrate; a magnetically susceptible body fixed in the cavity for exerting a force on the substrate; and an inductor located in juxtaposition to the magnetically susceptible body, wherein the body is movable upon operation of the inductor thereby moving the substrate.
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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) | 1994-01-28 | 1994-07-30 | 1995-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-28 | 1998-07-30 | 1999-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-28 | 2002-07-30 | 2003-01-29 | $7700.00 | Window Closed / Lapsed |