Patent CH669271A5 successfully refreshed from Google Patents.
Patent US5870351A successfully refreshed from Google Patents.
US5870351A
Expired / Lapsed
US
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Broadband microfabriated ultrasonic transducer and method of fabrication
Assignee: Leland Stanford Junior University
•
Filing: 1996-10-29
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Granted: 1999-02-09
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Expires: 2016-10-29
Abstract
Abstract A broadband microfabricated ultrasonic transducer which includes a plurality of resonant membranes of different sizes and/or shapes supported above a conductive substrate.
Inventors
- 👤 Igal Ladabaum
- 👤 Butrus Thomas Khuri-Yakub
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:15
CPC Classifications
B; B06; B06B; B06B1/00; B06B1/02; B06B1/0292; B06B1/06; B06B1/0688; B06B1/0696; H; H02; H02N; H02N1/00; H02N1/002; H02N1/006
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
44 words
A broadband microfabricated ultrasonic transducer comprising: a substrate; a plurality of resonant membranes of different sizes with each size selected for its resonant frequency supported spaced from the substrate by an insulating support; and means for applying voltages between said membranes and said substrate.
Claim 2
Dependent Claim
44 words
A broadband microfabricated ultrasonic transducer comprising: a substrate; a plurality of resonant membranes of different sizes with each size selected for its resonant frequency supported spaced from the substrate by an insulating support; and means for applying voltages between said membranes and said substrate.
Claim 3
Dependent Claim
20 words
A broadband microfabricated transducer as in claim 1 in which the membrane is silicon nitride having a predetermined residual stress.
Claim 4
Dependent Claim
15 words
A broadband transducer as in claim 1 in which the insulating support is silicon oxide.
Claim 5
Dependent Claim
14 words
A broadband transducer as in claim 1 in which the insulating support is parylene.
Claim 6
Dependent Claim
75 words
A transducer array comprising: a substrate; a plurality of ultrasonic transducers on said substrate, each of said transducers including a plurality of resonant membranes of different sizes with each size selected to resonate at a selected frequency or frequencies, said membranes each supported spaced from said substrate by an insulating support; and means for applying voltages between selected membranes and said substrate whereby to focus and/or scan the ultrasonic energy from said plurality of membranes.
Claim 7
Dependent Claim
75 words
A transducer array comprising: a substrate; a plurality of ultrasonic transducers on said substrate, each of said transducers including a plurality of resonant membranes of different sizes with each size selected to resonate at a selected frequency or frequencies, said membranes each supported spaced from said substrate by an insulating support; and means for applying voltages between selected membranes and said substrate whereby to focus and/or scan the ultrasonic energy from said plurality of membranes.
Claim 8
Dependent Claim
20 words
A broadband microfabricated transducer as in claim 5 in which the membrane is silicon nitride having a predetermined residual stress.
Claim 9
Dependent Claim
15 words
A broadband transducer as in claim 5 in which the insulating support is silicon oxide.
Claim 10
Dependent Claim
14 words
A broadband transducer as in claim 5 in which the insulating support is parylene.
Claim 11
Dependent Claim
19 words
A broadband transducer as in claims 6, 7, or 8 in which the transducers are in a linear array.
Claim 12
Dependent Claim
20 words
A broadband transducer as in claims 6, 7, or 8 in which the transducers are in a two dimensional array.
Claim 13
Dependent Claim
66 words
A broadband microfabricated ultrasonic transducer comprising: a conductive semiconductor substrate; a plurality of silicon nitride membranes of different sizes with each size selected for its resonant frequency, said membranes supported spaced from said substrate at their edges by an insulating support; and a conductive film formed on the surface of said membranes whereby a voltage can be applied between said membranes and said conductive semiconductor substrate.
Claim 14
Dependent Claim
66 words
A broadband microfabricated ultrasonic transducer comprising: a conductive semiconductor substrate; a plurality of silicon nitride membranes of different sizes with each size selected for its resonant frequency, said membranes supported spaced from said substrate at their edges by an insulating support; and a conductive film formed on the surface of said membranes whereby a voltage can be applied between said membranes and said conductive semiconductor substrate.
Claim 15
Dependent Claim
15 words
A broadband transducer as in claim 11 in which the insulating support is silicon oxide.
Claim 16
Dependent Claim
14 words
A broadband transducer as in claim 11 in which the insulating support is parylene.
Claim 17
Dependent Claim
42 words
A broadband transducer as in claim 11 in which the membranes have areas which range from 300 to 30,000 μm 2 and thicknesses which range from 0.1 to 1 μm, and an insulator support thickness which ranges from 0.1 to 2 μm.
Claim 18
Dependent Claim
18 words
A broadband transducer as in claims 11, 12, 13, or 14 in which the membranes have different shapes.
Claim 19
Independent Claim
102 words
The method of forming a broadband ultrasonic transducer which comprises the steps of: selecting a semiconductor conductive substrate forming a thin sacrificial insulating layer on one surface of said substrate; forming a thin silicon nitride layer on the surface of said insulating layer; forming a number of etchant access holes in said silicon nitride layer, said holes being closely spaced and arranged in patterns each including a plurality of spaced access holes; etching the sacrificial insulating layer through said access holes for a period of time which etches away the sacrificial material layer to form a membrane at each pattern of holes.
Claim 20
Independent Claim
102 words
The method of forming a broadband ultrasonic transducer which comprises the steps of: selecting a semiconductor conductive substrate forming a thin sacrificial insulating layer on one surface of said substrate; forming a thin silicon nitride layer on the surface of said insulating layer; forming a number of etchant access holes in said silicon nitride layer, said holes being closely spaced and arranged in patterns each including a plurality of spaced access holes; etching the sacrificial insulating layer through said access holes for a period of time which etches away the sacrificial material layer to form a membrane at each pattern of holes.
References Cited (Backward Citations)
DE892773C
Cited
US3715638A
Cited
US3736552A
Cited
US3946422A
Cited
US3786495A
Cited
US3973146A
Cited
US4081626A
Cited
US4432007A
Cited
US4262399A
Cited
US4246449A
Cited
US4439641A
Cited
US4429192A
Cited
US4439847A
Cited
US4530077A
Cited
US4533795A
Cited
US4887246A
Cited
US4910840A
Cited
US4783821A
Cited
US4922471A
Cited
US4916675A
Cited
US4887248A
Cited
US5241512A
Cited
US5208789A
Cited
US5408731A
Cited
US5619476A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-08 | 2002-08-10 | 2003-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-08 | 2006-08-10 | 2007-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-08 | 2010-08-10 | 2011-02-09 | $7700.00 | Window Closed / Lapsed |