Patent US3400410A successfully refreshed from Google Patents.
Patent US2269972A successfully refreshed from Google Patents.
Patent US5938612A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5938612A Expired / Lapsed US ⏱️ 0.0 years remaining

Multilayer ultrasonic transducer array including very thin layer of transducer elements

Assignee: Creare LLC
•
Filing: 1997-05-05
•
Granted: 1999-08-17
•
Expires: 2017-05-05
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract An ultrasonic transducer array having a plurality of transducer elements, at least some of which have multiple piezoelectric and electrode layers. The resonant frequency of the transducer elements may range from 500 kHz to 300 MHz or more. A single array may have transducer elements of different resonant frequencies, and the array may be sparsely populated. Highest frequencies are typically obtained when the piezoelectric layers are made from vapor deposited PZT in accordance with a disclosed deposition process. The array may have a 1-D configuration, 1.5-D or 2-D, configuration. The array may be positioned in a probe.

Inventors

  • 👤 Robert Kline-Schoder
  • 👤 Shinzo Onishi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 09:18
CPC Classifications
G; G01; G01S; G01S15/00; G01S15/88; G01S15/89; G01S15/8906; G01S15/895; G01S15/8956; B; B06; B06B; B06B1/00; B06B1/02; B06B1/06; B06B1/0607; B06B1/0622; B06B1/064; B06B1/0207; B06B1/0215; B06B2201/00; B06B2201/70; B06B2201/76; G01S15/8909; G01S15/8915

Claims Analysis

Total Claims: 65
Claim 1
Independent Claim 35 words
An ultrasonic transducer array comprising: a. at least one layer of PZT having a thickness of less than 50 microns; and b. an electrical conductor assembly attached to said at least one layer of PZT.
Claim 2
Dependent Claim 35 words
An ultrasonic transducer array comprising: a. at least one layer of PZT having a thickness of less than 50 microns; and b. an electrical conductor assembly attached to said at least one layer of PZT.
Claim 3
Dependent Claim 37 words
An ultrasonic transducer array according to claim 1, wherein said at least one layer of PZT comprises two or more layers of PZT and said electrical conductor assembly comprises first and second electrodes attached to said layers.
Claim 4
Dependent Claim 25 words
An ultrasonic transducer array according to claim 1, wherein said at least one layer of PZT has a thickness of no more than 10 microns.
Claim 5
Dependent Claim 52 words
An ultrasonic transducer array comprising: a. a plurality of piezoelectric layers; b. a plurality of electrode layers interposed between said plurality of piezoelectric layers; and c. wherein said ultrasonic transducer array is capable of operating at resonant frequencies in excess of 5 MHz with an electrical impedance of less than 100 Ohms.
Claim 6
Dependent Claim 52 words
An ultrasonic transducer array comprising: a. a plurality of piezoelectric layers; b. a plurality of electrode layers interposed between said plurality of piezoelectric layers; and c. wherein said ultrasonic transducer array is capable of operating at resonant frequencies in excess of 5 MHz with an electrical impedance of less than 100 Ohms.
Claim 7
Dependent Claim 24 words
An ultrasonic transducer array according to claim 4, wherein at least one of said piezoelectric layers has a thickness of less than 50 microns.
Claim 8
Dependent Claim 18 words
An ultrasonic transducer array according to claim 4, wherein said plurality of piezoelectric layers are made from PZT.
Claim 9
Dependent Claim 25 words
An ultrasonic transducer array according to claim 4, wherein said ultrasonic transducer array is capable of operating at resonant frequencies in excess of 10 MHz.
Claim 10
Dependent Claim 43 words
An ultrasonic transducer array according to claim 4, further comprising: d. a first electrical conductor assembly attached to first ones of said plurality of electrode layers; and e. a second electrical conductor assembly attached to second ones of said plurality of electrode layers.
Claim 11
Dependent Claim 34 words
An ultrasonic transducer array according to claim 4, further comprising a substrate having a first surface, wherein said plurality of piezoelectric layers and said plurality of electrode layers are provided on said first surface.
Claim 12
Dependent Claim 14 words
An ultrasonic transducer array according to claim 9, wherein said first surface is planar.
Claim 13
Dependent Claim 14 words
An ultrasonic transducer array according to claim 9, wherein said first surface is non-planar.
Claim 14
Dependent Claim 108 words
An ultrasonic transducer array comprising: a. a plurality of ultrasonic transducer elements, each having: i. a plurality of piezoelectric layers; ii. a plurality of first electrodes, each contacting at least one of said plurality of piezoelectric layers; iii. a plurality of second electrodes, each contacting at least one of said plurality of piezoelectric layers; b. a connector structure having: i. a plurality of first connectors attached to said plurality of first electrodes; ii. a plurality of second connectors attached to said plurality of second electrodes; and c. wherein at least some of said ultrasonic transducer elements contact one of said first connectors and two of said second connectors.
Claim 15
Dependent Claim 108 words
An ultrasonic transducer array comprising: a. a plurality of ultrasonic transducer elements, each having: i. a plurality of piezoelectric layers; ii. a plurality of first electrodes, each contacting at least one of said plurality of piezoelectric layers; iii. a plurality of second electrodes, each contacting at least one of said plurality of piezoelectric layers; b. a connector structure having: i. a plurality of first connectors attached to said plurality of first electrodes; ii. a plurality of second connectors attached to said plurality of second electrodes; and c. wherein at least some of said ultrasonic transducer elements contact one of said first connectors and two of said second connectors.
Claim 16
Dependent Claim 34 words
An ultrasonic transducer array according to claim 12, wherein said plurality of first connectors is electrically isolated from said second electrodes and said plurality of second connectors is electrically isolated from said first electrodes.
Claim 17
Dependent Claim 23 words
An ultrasonic transducer array according to claim 12, wherein said plurality of first connectors is electrically isolated from said plurality of second connectors.
Claim 18
Dependent Claim 18 words
An ultrasonic transducer array according to claim 12, wherein said plurality of piezoelectric layers are made from PZT.
Claim 19
Dependent Claim 63 words
An ultrasonic transducer array comprising: a. a plurality of adjacent ultrasonic transducer elements, each element having: i. a plurality of piezoelectric layers; ii. a plurality of electrode layers; b. a connector structure having a plurality of connectors connected to said plurality of electrode layers; and c. wherein at least two of said ultrasonic transducer elements are separated only by one of said connectors.
Claim 20
Dependent Claim 63 words
An ultrasonic transducer array comprising: a. a plurality of adjacent ultrasonic transducer elements, each element having: i. a plurality of piezoelectric layers; ii. a plurality of electrode layers; b. a connector structure having a plurality of connectors connected to said plurality of electrode layers; and c. wherein at least two of said ultrasonic transducer elements are separated only by one of said connectors.
Claim 21
Dependent Claim 24 words
An ultrasonic transducer array according to claim 16, wherein said at least two ultrasonic transducer elements physically contact said one connector separating said elements.
Claim 22
Dependent Claim 18 words
An ultrasonic transducer array according to claim 16, wherein said plurality of piezoelectric layers are made from PZT.
Claim 23
Dependent Claim 25 words
An ultrasonic transducer array according to claim 4, wherein said ultrasonic transducer array is capable of operating at resonant frequencies in excess of 15 MHz.
Claim 24
Dependent Claim 24 words
An ultrasonic transducer array according to claim 1, wherein said at least one layer of PZT has a thickness of less than 25 microns.
Claim 25
Dependent Claim 103 words
An ultrasonic transducer array comprising: a. a plurality of first ultrasonic transducer elements having a first resonant frequency, each element having two or more piezoelectric layers, and a first electrode assembly attached to said two or more piezoelectric layers; b. a plurality of second ultrasonic transducer elements having a second resonant frequency, each element having two or more piezoelectric layers, and a second electrode assembly attached to said two or more piezoelectric layers; and c. wherein said first and second resonant frequencies are different, and said plurality of first ultrasonic transducer elements are acoustically isolated from said plurality of second ultrasonic transducer elements.
Claim 26
Dependent Claim 103 words
An ultrasonic transducer array comprising: a. a plurality of first ultrasonic transducer elements having a first resonant frequency, each element having two or more piezoelectric layers, and a first electrode assembly attached to said two or more piezoelectric layers; b. a plurality of second ultrasonic transducer elements having a second resonant frequency, each element having two or more piezoelectric layers, and a second electrode assembly attached to said two or more piezoelectric layers; and c. wherein said first and second resonant frequencies are different, and said plurality of first ultrasonic transducer elements are acoustically isolated from said plurality of second ultrasonic transducer elements.
Claim 27
Dependent Claim 46 words
An ultrasonic transducer array according to claim 21, wherein said first resonant frequency is less than 0.3 times the average of said first and second resonant frequencies and said second resonant frequency is more than 1.7 times the average of said first and second resonant frequencies.
Claim 28
Dependent Claim 24 words
An ultrasonic transducer array according to claim 19, wherein said piezoelectric layers in said first and second ultrasonic transducer elements are made from PZT.
Claim 29
Dependent Claim 18 words
An ultrasonic transducer array according to claim 19, wherein said first and second electrode assemblies are electrically isolated.
Claim 30
Dependent Claim 36 words
An ultrasonic transducer array according to claim 19, wherein said plurality of first ultrasonic transducer elements are optimized to transmit ultrasonic energy and said plurality of second ultrasonic transducer elements are optimized to receive ultrasonic energy.
Claim 31
Dependent Claim 40 words
An ultrasonic transducer array according to claim 19, further comprising a substrate having a first, non-planar, surface, wherein said pluralities of first and second ultrasonic transducer elements and said first and second electrode assemblies are positioned on said first surface.
Claim 32
Dependent Claim 84 words
An ultrasonic transducer array comprising: a. N×M transducer element regions, wherein N is the number of said regions as measured in a first direction and M is the number of said regions as measured in a second direction; b. a plurality of ultrasonic transducer elements, each having one or more piezoelectric layers and an electrode assembly connected to said one or more piezoelectric layers; and c. wherein X(N×M) of said transducer element regions contain one of said plurality of ultrasonic transducer elements, and X<1.
Claim 33
Dependent Claim 84 words
An ultrasonic transducer array comprising: a. N×M transducer element regions, wherein N is the number of said regions as measured in a first direction and M is the number of said regions as measured in a second direction; b. a plurality of ultrasonic transducer elements, each having one or more piezoelectric layers and an electrode assembly connected to said one or more piezoelectric layers; and c. wherein X(N×M) of said transducer element regions contain one of said plurality of ultrasonic transducer elements, and X<1.
Claim 34
Dependent Claim 10 words
An ultrasonic transducer array according to claim 27, wherein X<0.5.
Claim 35
Dependent Claim 10 words
An ultrasonic transducer array according to claim 27, wherein X<0.25.
Claim 36
Dependent Claim 41 words
An ultrasonic transducer array according to claim 27, wherein said plurality of ultrasonic transducer elements comprises: a. a first group of ultrasonic transducer elements for transmitting ultrasonic energy; and b. a second group of ultrasonic transducer elements for receiving ultrasonic energy.
Claim 37
Dependent Claim 56 words
An ultrasonic transducer array according to claim 27, wherein said plurality of ultrasonic transducer elements comprises: a. a first group of ultrasonic transducer elements having a first resonant frequency; b. a second group of ultrasonic transducer elements having a second resonant frequency; and c. wherein said first resonant frequency is different than said second resonant frequency.
Claim 38
Dependent Claim 44 words
An ultrasonic transducer array according to claim 27, wherein said plurality of ultrasonic transducer elements comprises: a. a first group of ultrasonic transducer elements, each having one piezoelectric layer; b. a second group of ultrasonic transducer elements, each having two or more piezoelectric layers.
Claim 39
Dependent Claim 19 words
An ultrasonic transducer array according to claim 27, wherein said one or more piezoelectric layers are made from PZT.
Claim 40
Dependent Claim 23 words
An ultrasonic transducer array according to claim 27, wherein said plurality of ultrasonic transducer elements are randomly distributed in said transducer element regions.
Claim 41
Dependent Claim 68 words
An ultrasonic transducer array comprising a plurality of ultrasonic transducer elements, at least one of said elements having a resonant frequency greater than 10 MHz and three or more piezoelectric layers, said elements being arranged in a 1-D configuration, further wherein one or more of said elements has a length to width aspect ratio such that the length dimension is no more than five times the width dimension.
Claim 42
Dependent Claim 68 words
An ultrasonic transducer array comprising a plurality of ultrasonic transducer elements, at least one of said elements having a resonant frequency greater than 10 MHz and three or more piezoelectric layers, said elements being arranged in a 1-D configuration, further wherein one or more of said elements has a length to width aspect ratio such that the length dimension is no more than five times the width dimension.
Claim 43
Dependent Claim 19 words
An ultrasonic transducer array according to claim 35, wherein said length dimension is substantially equal to said width dimension.
Claim 44
Dependent Claim 17 words
An ultrasonic transducer array according to claim 35, wherein said resonant frequency is greater than 15 MHz.
Claim 45
Dependent Claim 33 words
An ultrasonic transducer array having a plurality of multilayer transducer elements, each having height, width and length dimensions, wherein at least one of said width and length dimensions is less than 50 microns.
Claim 46
Dependent Claim 33 words
An ultrasonic transducer array having a plurality of multilayer transducer elements, each having height, width and length dimensions, wherein at least one of said width and length dimensions is less than 50 microns.
Claim 47
Dependent Claim 23 words
An ultrasonic transducer array according to claim 38, wherein at least one of said width and length dimensions does not exceed 25 microns.
Claim 48
Dependent Claim 23 words
An ultrasonic transducer array according to claim 38, wherein said width dimension times said length dimension does not exceed 0.0025 mm 2 .
Claim 49
Dependent Claim 23 words
An ultrasonic transducer array according to claim 38, wherein said width dimension times said length dimension does not exceed 0.000625 mm 2 .
Claim 50
Dependent Claim 18 words
An ultrasonic transducer array according to claim 38, wherein said length dimension is 1-5 times said width dimension.
Claim 51
Dependent Claim 17 words
An ultrasonic transducer array according to claim 38, wherein said elements are arranged in a 2-D array.
Claim 52
Independent Claim 41 words
A method of making an ultrasonic transducer array comprising the steps of: a. providing a first electrode; and b. vapor depositing a first PZT layer on said first electrode, said first PZT layer having a thickness of more than 5 microns.
Claim 53
Independent Claim 41 words
A method of making an ultrasonic transducer array comprising the steps of: a. providing a first electrode; and b. vapor depositing a first PZT layer on said first electrode, said first PZT layer having a thickness of more than 5 microns.
Claim 54
Dependent Claim 33 words
A method according to claim 44, further comprising the steps of: a. providing a second electrode on said first PZT layer; and b. vapor depositing a second PZT layer on said second electrode.
Claim 55
Dependent Claim 37 words
A method according to claim 45, further comprising the steps of: a. isolating first portions of said first electrode from second portions of said first electrode; and b. providing a first connector attached to said first electrode.
Claim 56
Dependent Claim 33 words
A method according to claim 46, wherein said isolating step comprises the steps of: i. forming a kerf extending through said first electrode; and ii. depositing an acoustically isolating material in said kerf.
Claim 57
Dependent Claim 19 words
A method according to claim 44, wherein said first PZT layer has a thickness of more than 10 microns.
Claim 58
Independent Claim 31 words
A method of depositing PZT material comprising the steps of: a. providing a substrate; b. vapor depositing PZT on said substrate at a rate of at least 0.5 microns per hour.
Claim 59
Independent Claim 31 words
A method of depositing PZT material comprising the steps of: a. providing a substrate; b. vapor depositing PZT on said substrate at a rate of at least 0.5 microns per hour.
Claim 60
Dependent Claim 76 words
A method according to claim 49, wherein said step b comprises the steps of: i. providing a vapor deposition device; ii. providing a target having at least one first portion made from zirconium and at least one second portion made from titanium, wherein the ratio of the surface area of said first portion to the surface area of said second portion ranges from 40% to 55%; and iii. positioning said target in said vapor deposition device.
Claim 61
Dependent Claim 19 words
A method according to claim 49, wherein said PZT is deposited to a thickness of more than 5 microns.
Claim 62
Dependent Claim 73 words
A method according to claim 49, wherein said step b includes the steps of: i. providing a target in a vapor deposition device, said target comprising first portions made from zirconium, second portions made from titanium and third portions made from lead; and ii. sputtering said first, second and third portions in an environment containing oxygen so as to cause lead oxide, zirconium oxide and titanium oxide to be deposited on said substrate.
Claim 63
Independent Claim 28 words
A method of depositing PZT material comprising the steps of: a. providing a substrate; b. vapor depositing PZT on said substrate to thickness of more than 5 microns.
Claim 64
Independent Claim 28 words
A method of depositing PZT material comprising the steps of: a. providing a substrate; b. vapor depositing PZT on said substrate to thickness of more than 5 microns.
Claim 65
Dependent Claim 22 words
A method according to claim 53, wherein said step b involves depositing said PZT to a thickness of more than 10 microns.

References Cited (Backward Citations)

US4233135A Cited
US4297189A Cited
US4509524A Cited
US4592029A Cited
US4841977A Cited
US5744898A Cited
US5297553A Cited
US5329496A Cited
US5423220A Cited
US5605154A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2002-08-16 2003-02-15 2003-08-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-08-16 2007-02-15 2007-08-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-08-16 2011-02-15 2011-08-17 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag