EP0620049A2 - Transducteur acoustique à couches multiples - Google Patents

Transducteur acoustique à couches multiples Download PDF

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Publication number
EP0620049A2
EP0620049A2 EP94302655A EP94302655A EP0620049A2 EP 0620049 A2 EP0620049 A2 EP 0620049A2 EP 94302655 A EP94302655 A EP 94302655A EP 94302655 A EP94302655 A EP 94302655A EP 0620049 A2 EP0620049 A2 EP 0620049A2
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EP
European Patent Office
Prior art keywords
layers
piezoelectric
layer
electrode
voltage signal
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94302655A
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German (de)
English (en)
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EP0620049A3 (fr
Inventor
Michael Greenstein
Paul Lum
Henry Yoshida
Hewlett E. Jn. Melton
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HP Inc
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Hewlett Packard Co
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Publication of EP0620049A2 publication Critical patent/EP0620049A2/fr
Publication of EP0620049A3 publication Critical patent/EP0620049A3/fr
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
    • B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
    • B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
    • B06B1/064—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface with multiple active layers

Definitions

  • This invention relates to acoustic transducers for medical imaging using multilayer piezoelectric materials, and to improvements in acoustic signal definition and bandwidth.
  • a diagnostic ultrasonic imaging system forms images of tissues inside the human body by electrically exciting a transducer or array of transducers to generate short ultrasonic pulses, which then travel into the body.
  • a transducer or array of transducers then converts the ultrasonic echoes from the tissues into electrical signals which are amplified and used to form a cross sectional image of the tissue.
  • transducers used for medical imaging consist of a single layer of piezoelectric material that requires excitation with a high voltage for generating short ultrasonic pulses.
  • the echo signals are often amplified with low voltage integrated circuit electronics.
  • the high excitation voltage is an impediment to integrating low voltage, high density circuitry with a transducer or an array of transducers.
  • a two-dimensional acoustic array with a large number of acoustic elements requires local integrated electronics to achieve acceptable performance. It is both desirable and beneficial to strive for use of a low voltage transducer that can be excited by standard low voltage integrated circuit electronics.
  • Use of low voltage transducers also reduces the potential of electrical hazard to the patient.
  • Berlincourt, et al. disclose use of two or more piezoelectric layers in a stack on a substrate, with an independent common electrode being positioned between any two adjacent piezoelectric layers, in U.S. Patent No. 3,590,287.
  • the objective is to provide improved filters and transformers for signal processing applications.
  • Two adjacent piezoelectric layers are chosen to have the same or opposite electrical polarities, and two adjacent piezoelectric layers are chosen to have the same or different piezoelectric properties.
  • Piezoelectric layer thicknesses are chosen to achieve a particular fixed resonant frequency for the structure. No discussion is presented of the issue of fringe fields poling or operation.
  • the transducer should operate at low voltages and should control the development of spurious lateral modes that arise from fringe electric fields in the piezoelectric material which originate from poling the assembled resonator stack as well as the operation of the transducer with side electrodes.
  • the invention provides for fabrication of one or an array of low voltage, multilayer transducers, each transducer having side or external electrodes using a controllable, uniform poling field for an assembled acoustic resonator stack and using a static or time-dependent electrical field during operation.
  • an array of acoustic transducers for producing an electrical signal in response to passage of an incident acoustic wave therethrough and for producing an acoustic wave in response to receipt of an electrical signal
  • the number of piezoelectric layers may be two, and they may have approximately equal thickness t1 and t2, or unequal thicknesses t1 and t2.
  • One of said thicknesses t1 and t2 may be approximately twice as large as the other of said thicknesses.
  • the number of piezoelectric layers may be three, and they may have approximately equal thicknesses t1,t2 and t3 in which the thickness ratios t1, t2 and t3 may be approximately 1:3:2 or 2:3:1.
  • the voltage signals impressed upon the electrode layers by said voltage signal transceivers may be changeable dynamically.
  • the invention provides a multilayer acoustic transducer including a plurality of N piezoelectric layers (of equal or unequal thicknesses), in a piezoelectric resonator stack, each with top and bottom electrode layers.
  • An optional adjacent matching layer and with an optional backing layer are provided. The requirements for the properties of the matching and the backing layers are well known by those skilled in the art.
  • each electrode layer Electrical connections are provided from each electrode layer to a time-varying voltage source for transmitting acoustic signals, and to an amplifier that receives acoustic echoes.
  • the total thickness of the piezoelectric resonator stack is an odd multiple of ⁇ /4 or ⁇ /2 for a predetermined wavelength ⁇ of an acoustic wave passing through the transducer.
  • Adjacent piezoelectric layers have their poling directions oriented in the same direction or in opposite directions.
  • Each piezoelectric layer has one or two edge dielectric layers that controls fringe electric fields and lateral modes that would otherwise develop.
  • the electrodes for each piezoelectric layer are independently addressable from a multiplexer circuit, and the electrodes are electrically isolated from each other by internal dielectric layers positioned in the acoustic wave path. Side electrodes can be used to connect the piezoelectric layers electrically in parallel.
  • Multifrequency operation of the transducer is achieved with a multilayer transducer, including a plurality of equal or unequal thickness piezoelectric layers, with an optional matching layer and with an optional backing layer.
  • This arrangement mechanically in series and electrically in parallel, provides impedance control as well as voltage control.
  • a single transducer or an array of transducers positioned side-by-side can be provided.
  • the number N of piezoelectric layers is even, which allows some structural simplifications.
  • impedance normalization for different area transducer elements in a two-dimensional acoustic array is achieved with a multilayer transducer, including a plurality of N piezoelectric layers (of equal or unequal thicknesses), with an optional matching layer and an optional backing layer.
  • the electrodes for the piezoelectric layers are arranged in either dedicated or dynamically variable series-parallel combinations to maintain the ratio of the electrical impedance to the element area as a constant across a two-dimensional acoustic array including elements of varying areas.
  • the transverse areas of the piezoelectric layers in each stack are selected to maintain the same impedance across a two-dimensional transducer array.
  • Figures 1A, 1B and 1C illustrate a portion of an embodiment of the invention with a single piezoelectric layer and an edge dielectric layer.
  • Figure 3 illustrates the multilayer resonator stack assembled into a transducer.
  • Figure 4 illustrates use of a curvilinear interface for an edge dielectric layer and adjacent electrodes.
  • FIGS 5A and 5B illustrate achievement of reduced impedance for multilayer transducers according to the invention.
  • Figures 6A and 6B illustrate achievement of voltage reduction and multi frequency operation for multilayer transducers according to the invention.
  • Figures 7A, 7B, 7C and 7D illustrate the effect of poling direction on two-layer and three-layer structures.
  • Figure 8 illustrates a cylindrical multilayer transducer structure.
  • Figures 9A and 9B illustrate multifrequency operation of a transducer using isolated internal electrode layers and a multiplexer circuit.
  • Figures 10A-10F illustrate multifrequency operation using the largest nonredundant integer resonator stack.
  • Figures 11A-11D illustrate achievement of impedance control based on series/parallel interconnection combinations.
  • Figure 12 illustrates one embodiment for achievement of impedance normalization for two-dimensional arrays based on impedance control.
  • Figures 1A, 1B and 1C illustrate one embodiment of the invention, the piezoelectric layer, including an active piezoelectric layer 10, edge dielectric layers 11A and 11B, and conductive electrode layers 12A and 12B.
  • an edge dielectric layer 11A or 11B does not completely surround the active piezoelectric layer.
  • an edge dielectric layer 11 may completely surround the active piezoelectric layer.
  • Figure 1C is a cross sectional end view of the combination of layers.
  • a typical thickness of the conductive electrode is in the range of 100 to 5000 ⁇ .
  • the conductive electrodes 12A and 12B are shown with exaggerated thickness for clarity.
  • each of the edge dielectric layers 11A and 11B in Figure 1C physically separates the electrode layers 12A and 12B from each other and minimizes excitation of undesirable lateral modes within the piezoelectric layer 10 in the transmit mode, which arise from fringe electrical fields for previously poled piezoelectric material or from fringe fields for multilayer piezoelectric resonator stacks poled in situ. If pairs of side electrodes that contact a given piezoelectric layer directly on two parallel sides of the piezoelectric layer were used here, lateral modes could be excited in that piezoelectric layer.
  • the type and properties of the dielectric chosen for the edge dielectrics 11A and 11B will determine the magnitudes of the fringe electric fields.
  • Suitable dielectric materials for the edge dielectric layers and for optional internal dielectric layers discussed below include: oxides, such as SiO z (z ⁇ 1); ceramics, such as Al2O3 and PZT; refractory materials, such as Si x N y , BN and AlN; semiconductors, such as Si, Ge and GaAs; and polymers, such as epoxy and polyimide.
  • Figure 2A illustrates one embodiment of the invention, the piezoelectric resonator stack, for fixed electrically parallel excitation of equal thickness piezoelectric layers with opposite poling vector direction.
  • the poling vectors for the electrical fields impose across the piezoelectric layers are indicated by the vertically directed arrows.
  • the active piezoelectric layers 20A, 20B and 20C have adjacent edge dielectric layers 21A/21B, 21C/21D and 21E/21F, respectively, and adjacent conductive electrodes 22A/22B, 22C/22D and 22E/22F, respectively, with external side conductive electrodes 23A and 23B as shown.
  • a single edge dielectric layer, such as 21B, 21D and 21E can be provided adjacent to each piezoelectric layer.
  • the individual piezoelectric layers 20A, 20B and 20C in Figures 2A and 2B are attached together with internal dielectric layers 24A and 24B (optional), and respective bonding layers 25A/25B and 25C/25D (optional).
  • the thicknesses of the electrode layers 22A-22D, the bonding layers 25A-25D and the internal dielectric layers 24A-24B are shown in Figures 2A and 2B with exaggerated thicknesses for clarity.
  • Typical thicknesses of a bond layer and of an internal dielectric layer are less than 1 ⁇ m, and less than 100 ⁇ m, respectively.
  • each electrode layer 21A-21F can be electrically connected to one terminal of a group of one or more voltage signal sources 29A or signal amplifiers 29B. If the internal dielectric layers 24A-24B and the bonding layers 25A-25D are deleted, some of the intermediate electrode layers, such as 22B and 22D, can be optionally deleted so that the transducer requires as few as N+1 electrode layers for an N-layer stack.
  • the total thickness T of the piezoelectric resonator stack includes the thicknesses of the piezoelectric layers t i , the thickness of the internal dielectric layers h i , and the thicknesses of the bonding layers k i .
  • the thicknesses of the conductive electrodes are negligible here.
  • a multilayer resonator stack may also be constructed from layers that are limited (by other constraints) in their individual maximum thicknesses. This situation may occur with layers deposited in situ by sputtering or evaporation or sol-gel deposition, for example. In this situation, each layer might be restricted to a maximum thickness, t max , which may be of the order of 1-10 ⁇ m, while the resonator has a desired thickness ⁇ /2 >> t max .
  • FIG. 3 illustrates a complete acoustic transducer for fixed electrical parallel excitation according to the invention, with opposite poling directions for three consecutive piezoelectric layers.
  • This transducer includes: three parallel, spaced apart piezoelectric layers 30A, 30B and 30C; three pairs 31A/31B, 31C/31D and 31E/31F of side dielectric layers flanking the piezoelectric layers 30A, 30B and 30C, respectively; three pairs 32A/32B, 32C/32D and 32E/32F of individually controlled electrodes that surround the respective piezoelectric layers 30A, 30B and 30C; an internal dielectric layer (not shown in Figure 3) separating the electrodes 31B and 31C; an internal dielectric layer (not shown in Figure 3) separating the electrodes 31D and 31E; end electrodes 33A and 33B that flank all other components on the left and right, respectively; two dielectric end spacers 35A and 35D; a dielectric spacer 35B that separates the electrodes 32A, 32B
  • An acoustic wave 38 is received by the apparatus in the receive mode, or issued by the apparatus in the transmit mode.
  • a single dielectric edge layer, such as 31A, 31C and 31E, can be provided in place of the pairs of flanking edge dielectric layers 31A-31F. Alternatively, one can delete the edge dielectric layers.
  • the optional matching layer 36 is provided to suppress or minimize losses experienced by the acoustic wave 38 as the wave passes from the ambient-matching layer interface into and through the matching layer-piezoelectric layer interface.
  • the material for the matching layer 36 may be graphite, epoxy, Mylar, polyimide or other similar compounds, with an acoustic impedance between that of the piezoelectric and that of the ambient medium, preferably being the geometric mean of the acoustic impedances of the two adjacent layers.
  • the optional backing layer 37 of material is provided to suppress backward traveling waves produced by the acoustic wave 38.
  • the material for the backing layer 37 may be a heavy metal, such as tungsten, in a lighter matrix such a polymer or a ceramic.
  • Figure 4 illustrates a further refinement of the electrical connection between first and second conductive electrodes 42A or 42B, and an external or side electrode 43.
  • the reliability of the electrical contact can be improved by providing rounded or arcuate surfaces 44A and 44B on the adjacent edge dielectrics 41A and 41B and rounded or arcuate surfaces 45A and 45B at the interface of the two conductive electrode layers 42A and 42B with the external electrode 43.
  • the external side conductive electrode 43 is deposited after the piezoelectric layers 40A and 40B and the edge dielectric layers 41A and 41B are bonded together, thus allowing the side electrode to conform to the geometry of the rounded corners as shown.
  • a multilayer piezoelectric resonator stack has several useful features, if the individual piezoelectric layers are of uniform thickness, ti, and the adjacent piezoelectric layers have opposite poling directions. In this configuration, the piezoelectric layers act mechanically in series, but act electrically in parallel.
  • Figure 5 illustrates how impedance reduction can be achieved for a multilayer transducer, where the piezoelectric layers are electrically connected in parallel.
  • a single piezoelectric layer of thickness T (the "comparison layer") requires an applied voltage of V0
  • a multilayer resonator stack of N piezoelectric layers, also of total thickness T, constructed as indicated in Figures 2A and 2B, with parallel electrical connections requires an applied voltage of only V0/N to achieve an equivalent piezoelectric stress field. This occurs because of the reduced piezoelectric layer thickness between adjacent electrodes.
  • the required applied transmit voltage for the comparison layer is 50-200 Volts, the required applied voltage for a multilayer resonator stack can easily be reduced to the range 5-15 Volts, which is suitable for integration with high density integrated circuits.
  • Each piezoelectric layer in the multilayer resonator stack is a ⁇ /2 resonator operating at N times the fundamental frequency f0 for the comparison single layer resonator, neglecting the effect of strong coupling between the piezoelectric layers.
  • a multilayer resonator stack can also operate as a multifrequency acoustic transducer with a plurality of discrete fundamental frequencies.
  • Figures 6A and 6B illustrate how voltage reduction can be achieved for a multilayer transducer where the piezoelectric layers are electrically connected in parallel, and how multifrequency operation occurs when the piezoelectric layers are electrically connected individually.
  • an applied voltage of V0 gives a resonance frequency of f0, for a thickness of ⁇ /2.
  • the possible resonance frequencies are f0, 3f0/2, and 3f0., using three, two or one piezoelectric sub-layers in combination, respectively.
  • Figures 7A, 7B, 7C and 7D illustrate the effect on the spatial distribution of the electric field E and the fundamental resonant frequency of the piezoelectric resonator stack for parallel electrical connections for both parallel and opposite poling directions in adjacent piezoelectric layers.
  • Positioned below each transducer configuration is a plot of the electric field as a function of distance x, measured from front to back (or inversely) through a multilayer piezoelectric stack.
  • the configurations of Figures 7A and 7B produce resonant frequencies of f0 and 2f0, respectively.
  • Figures 7C and 7D produce resonant frequencies of f0 and 3f0, respectively.
  • a matching layer and a backing layer both optional) are omitted for clarity.
  • An acoustic wave 88 is shown for both transmit and receive modes of operation.
  • Three piezoelectric layers 80A, 80B and 80C are shown without internal conductive electrodes and bonding layers for clarity.
  • Two side electrodes 83A and 83B of opposite polarity wrap around the bottom and the top, respectively, of the cylinder.
  • Insulating dielectric layers 85A and 85B isolate the two electrodes 83A and 83B.
  • a voltage source 89A for the transmit mode and an differential amplifier 89B for the receive mode are also incorporated.
  • Multifrequency operation may be achieved if the electrodes are individually addressable. This requires use of thin electrical isolation layers that minimally perturb an acoustic wave that passes therethrough.
  • Piezoelectric layers 90A, 90B and 90C have respective conductive electrode pairs 92A/92B, 92C/92D and 92E/92F, respective edge dielectric pairs 91A/91B, 91C/91D and 91E/91F, and bonding layers 95A, 95B, 95C and 95D as shown in Figure 9A.
  • the internal electrodes 92B, 92C, 92D and 92E are isolated with internal dielectric layers 94A and 94B. Each of the electrodes 92A, 92B, 92C, 92D, 92E and 92F is connected to an individual signal line 93A, 93B, 93C, 93D, 93E and 93F, respectively, all of which are connected to a multiplexer circuit 97.
  • a voltage source 99A, for the transmit mode, and an amplifier 99B, for the receive mode, are also provided.
  • the table shown in Figure 9B exhibits the various voltage assignments required for the signal lines 93A-93F to produce resonance frequencies of f0, 3f0/2, and 3f0. For example, an assignment of voltage V0 to signal lines 93B, 93C and 93F will produce a resonant frequency f0.
  • a multifrequency transducer may also be constructed by use of non-uniform thicknesses for the piezoelectric layers.
  • These non-uniform thickness piezoelectric layers may be assembled from uniform thickness layers that are permanently connected together to form non-uniform thickness layers.
  • Figure 10A produces a resonant frequency f0 with piezoelectric layers 100A, 100B and 100C, all connected in series.
  • Figure 10B produces a resonant frequency 1.2f0 result using piezoelectric layers 102A, 102B and 102C, where only the piezoelectric layers 102A and 102B are connected in series.
  • Figure 10C produces a resonant frequency 1.5f0 result using the piezoelectric layers 104A, 104B and 104C, where only the piezoelectric layers 104B and 104C are connected in series.
  • Figure 10D produces a resonant frequency 2f0 result using piezoelectric layers 106A, 106B and 106C, where only the piezoelectric layer 106B is connected.
  • Figure 10E produces a resonant frequency 3f0 result using piezoelectric layers 108A, 108B and 108C, where only the piezoelectric layer 108A is connected.
  • Figure 10F produces a resonant frequency 6f0 result using piezoelectric layers 110A, 110B and 110C, where only the piezoelectric layer 110C is connected .
  • All N-layer resonator stacks (N ⁇ 4) with integer ratios of thicknesses generate a sequence of frequencies, using adjacent layers, that contains redundant frequencies. The ratio of individual layer thicknesses for a multilayer, multifrequency transducer is not restricted to integral multiples of a single thickness.
  • Four different electrical impedance values may be achieved: Z0, Z0/2, 2Z0/9, Z0/9 for the embodiments of Figures 11A, 11B, 11C and 11D, respectively.
  • Each interconnection combination for the Figures 11A-11D is shown with an accompanying electrical circuit diagram for clarity.
  • Figure 11A illustrates the series combination, with piezoelectric layers 120A, 120B and 120C, edge dielectrics 121A and 121B, external electrodes 122A and 122B, and internal electrodes 122C and 122D.
  • Figure 11B illustrates a series-parallel combination, with the same components.
  • Figure 11C illustrates a second series-parallel combination, with the same components.
  • Figure 11D illustrates a parallel combination, with the same components.
  • This set of impedances is shown with a dedicated set of electrical connections, but may also be achieved with a dynamically configurable set of electrical connections.
  • the ability to control the electrical impedance of a multilayer resonator stack by arrangement of the electrical connections between the layers can be used to approximately equalize the impedances of different multilayer resonator stacks.
  • This ability can , for example, be usefully applied to a coarsely sampled two-dimensional array, where the elevation aperture is divided into separate elements of various sizes. The smaller area elevation elements will have a higher associated electrical impedance (inversely proportional to area of an element) than a larger area elevation element. Equalization of electrical impedance is useful because the driving electronics then senses that all electrical loads are approximately the same.
  • the preceding discussions and illustrative figures have focused on a single transducer stack of piezoelectric layers and associated electrode and dielectric layers.
  • the invention also contemplates an array of J such transducers (J ⁇ 1), positioned side by side, with an incident acoustic wave passing through one, several or all of the J transducers in the usual manner.
  • Two or more transducer elements j1 and j2 (1 ⁇ j1 ⁇ j2 ⁇ J) may have different transverse areas A j1 and A j2 presented to the acoustic wave, to provide other control parameters for shaping or analyzing an acoustic wave.
  • the area for each elevation element, indicated at the right in Figure 12, is chosen to maintain the ratio of electrical impedance to transverse area as a constant for each independent stack. Therefore, if the total area of an elevation group scales with the electrical impedance for that group, achieved by resonator stack wiring such as shown in Figures 11A-11D, the electrical load seen by the driving electronics will be equalized across all elevation groups or stacks.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Piezo-Electric Transducers For Audible Bands (AREA)
EP94302655A 1993-04-16 1994-04-14 Transducteur acoustique à couches multiples. Withdrawn EP0620049A3 (fr)

Applications Claiming Priority (2)

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US4860493A 1993-04-16 1993-04-16
US48604 1993-04-16

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EP0620049A2 true EP0620049A2 (fr) 1994-10-19
EP0620049A3 EP0620049A3 (fr) 1995-09-06

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003076084A1 (fr) * 2002-03-12 2003-09-18 Koninklijke Philips Electronics N.V. Ensemble transducteur ultrasonore piezoelectrique comprenant des electrodes internes et permettant une augmentation de largeur de bande et une suppression de modes parasites
US6928722B2 (en) * 1999-06-03 2005-08-16 Tdk Corporation Magnetic disc apparatus and magnetic head in which a recording/reproduction element is mounted on a slider via a piezoelectric element
WO2008057004A1 (fr) * 2006-11-10 2008-05-15 Sergey Vladimirovich Shishov Procédé de conversion de signaux électriques en oscillations acoustiques et transducteur électro-gazo-cinétique polyforme
US9105836B2 (en) 2011-12-13 2015-08-11 Piezotech Llc Enhanced bandwidth transducer for well integrity measurement
EP2977115A4 (fr) * 2013-03-18 2016-10-26 Olympus Corp Dispositif de vibration ultrasonore stratifié, procédé de fabrication de dispositif de vibration ultrasonore stratifié et appareil médical ultrasonore
CN106456113A (zh) * 2014-03-13 2017-02-22 诺维欧扫描有限责任公司 高电压mems，以及包括这种mems的便携式超声设备
WO2020083672A1 (fr) * 2018-10-26 2020-04-30 Dolphitech As Appareil de balayage
CN112638293A (zh) * 2018-08-30 2021-04-09 奥林巴斯株式会社 超声波振子、超声波处置器具及超声波振子的制造方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6530887B1 (en) * 1996-12-24 2003-03-11 Teratech Corporation Ultrasound probe with integrated electronics
JP5560855B2 (ja) * 2010-03-31 2014-07-30 コニカミノルタ株式会社 超音波トランスデューサおよび超音波診断装置
JP5487007B2 (ja) * 2010-05-20 2014-05-07 日立アロカメディカル株式会社 超音波探触子及び超音波探触子の製造方法
JP6567955B2 (ja) * 2015-10-29 2019-08-28 京セラ株式会社 圧電素子およびこれを備えた音響発生器、音響発生装置、電子機器

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US4803763A (en) * 1986-08-28 1989-02-14 Nippon Soken, Inc. Method of making a laminated piezoelectric transducer
JPS63122288A (ja) * 1986-11-12 1988-05-26 Nec Corp 電歪効果素子

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JAPANESE JOURNAL OF APPLIED PHYSICS, SUPPLEMENTS, vol. 28, no. 1, March 1989 TOKYO JA, pages 54-56, XP 000085263 S.SAITOH EA 'A low impedance ultrsonic probe using a multilayer piezoelectric ceramic' *
PATENT ABSTRACTS OF JAPAN vol. 012 no. 375 (E-666) ,7 October 1988 & JP-A-63 122288 (NEC CORP) 26 May 1988, *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6928722B2 (en) * 1999-06-03 2005-08-16 Tdk Corporation Magnetic disc apparatus and magnetic head in which a recording/reproduction element is mounted on a slider via a piezoelectric element
US7082671B2 (en) 1999-06-03 2006-08-01 Tdk Corporation Magnetic disc apparatus production method
WO2003076084A1 (fr) * 2002-03-12 2003-09-18 Koninklijke Philips Electronics N.V. Ensemble transducteur ultrasonore piezoelectrique comprenant des electrodes internes et permettant une augmentation de largeur de bande et une suppression de modes parasites
WO2008057004A1 (fr) * 2006-11-10 2008-05-15 Sergey Vladimirovich Shishov Procédé de conversion de signaux électriques en oscillations acoustiques et transducteur électro-gazo-cinétique polyforme
US8085957B2 (en) 2006-11-10 2011-12-27 Sergey Vladimirovich Shishov Method for converting electric signals into acoustic oscillations and an electric gas-kinetic transducer
US9105836B2 (en) 2011-12-13 2015-08-11 Piezotech Llc Enhanced bandwidth transducer for well integrity measurement
EP2977115A4 (fr) * 2013-03-18 2016-10-26 Olympus Corp Dispositif de vibration ultrasonore stratifié, procédé de fabrication de dispositif de vibration ultrasonore stratifié et appareil médical ultrasonore
CN106456113A (zh) * 2014-03-13 2017-02-22 诺维欧扫描有限责任公司 高电压mems，以及包括这种mems的便携式超声设备
CN112638293A (zh) * 2018-08-30 2021-04-09 奥林巴斯株式会社 超声波振子、超声波处置器具及超声波振子的制造方法
WO2020083672A1 (fr) * 2018-10-26 2020-04-30 Dolphitech As Appareil de balayage

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EP0620049A3 (fr) 1995-09-06
JPH06319734A (ja) 1994-11-22

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