EP0118837A2 - Ultrasonic transducer - Google Patents

Ultrasonic transducer Download PDF

Info

Publication number
EP0118837A2
EP0118837A2 EP84102147A EP84102147A EP0118837A2 EP 0118837 A2 EP0118837 A2 EP 0118837A2 EP 84102147 A EP84102147 A EP 84102147A EP 84102147 A EP84102147 A EP 84102147A EP 0118837 A2 EP0118837 A2 EP 0118837A2
Authority
EP
European Patent Office
Prior art keywords
layer
ultrasonic transducer
receiving layer
piezoelectric plastic
transducer according
Prior art date
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.)
Granted
Application number
EP84102147A
Other languages
German (de)
French (fr)
Other versions
EP0118837B1 (en
EP0118837A3 (en
Inventor
Reinhard Dr. Lerch
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens AG
Original Assignee
Siemens AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Priority to AT84102147T priority Critical patent/ATE35338T1/en
Publication of EP0118837A2 publication Critical patent/EP0118837A2/en
Publication of EP0118837A3 publication Critical patent/EP0118837A3/en
Application granted granted Critical
Publication of EP0118837B1 publication Critical patent/EP0118837B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/02—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators

Definitions

  • the invention relates to an ultrasonic transducer with a support body, a transmission layer made of a material with a relatively high dielectric constant and a first ⁇ / 4 adaptation layer, which faces the transmission layer, and a second ⁇ / 4 adaptation layer, which faces a load.
  • Ultrasonic broadband converters are used in medical ultrasound diagnostics and non-destructive material testing.
  • the medical application where a coupling between tissue and sound transducer must be carried out with the lowest possible losses, requires an improvement in the electromechanical and acoustic properties of these transducer systems.
  • An ultrasonic transducer is known, the ceramic transducer of which is adapted to a load medium, tissue or water, by means of two A / 4 adaptation layers.
  • This transducer system contains an epoxy resin backing with an acoustic impedance of 3x10 6 Pas / m, a ceramic transducer, a first ⁇ / 4 matching layer made of glass with an acoustic impedance of 10x10 6 Pas / m and a second 1/4 matching layer made of polyacrylic or made of epoxy resin with an acoustic impedance of 3x10 6 Pas / m.
  • the ceramic converter is arranged on a backing.
  • the glass plate as the first adjustment layer is very adhesive with an adhesive low viscosity, so that adhesive layers are in the range of about 2 microns.
  • the epoxy resin, as the second adaptation layer is poured directly onto the first adaptation layer (experimental studies on the construction of ultrasound broadband transducers, biomedical engineering, volume 27, issues 7 to 8, 1982, pages 182 to 185). This double ⁇ / 4 adaptation only improves the sensitivity and the bandwidth of the ceramic transmission layer. The bandwidth of this ultrasonic transducer is approximately 60 to 70% of the center frequency.
  • an ultrasonic transducer which has a transmission layer made of a material with a relatively high dielectric constant and high sound impedance and a reception layer made of a material with a relatively low dielectric constant and low sound impedance, which are connected flatly in hybrid technology.
  • the transmission layer consists, for example, of lead zirconate titanate PZT or lead metaniobate Pb (NG 3 ).
  • the receiving layer consists of a piezoelectric plastic film with an acoustic impedance of approximately 3 ⁇ 10 6 Pas / m, for example polyvinylidene fluoride PVDF or polycarbonate or polyvinyl chloride PVC.
  • the receiving layer should also be an adaptation layer for the transmission case (German patent specification 29 14 031).
  • the formation of the receiving layer as an adaptation layer for adaptation to body tissue can, however, only be designed as a simple ⁇ / 4 layer.
  • the adaptation layer for the transmission case is not a simple / 4 adaptation. With a simple 1/4 adjustment, the theory results in an adjustment layer with an acoustic impedance of about 7x10 6 Pas / m.
  • the invention is based on the object of specifying an ultrasonic transducer with an effective broadband transmitter and a sensitive and broadband receiver.
  • the ceramic vibrating material of the transmission layer is to be broadband adapted to tissue or water.
  • the receiving layer consists of a stack of thin piezoelectric plastic films that are electrically connected in series. This design of the receiving layer makes it easier to polarize the individual piezoelectric plastic films due to the small thickness.
  • the receiving layer consists of an active and a passive piezoelectric plastic film, the active piezoelectric plastic film being arranged on the first adaptation layer and the passive piezoelectric plastic film facing the load.
  • the thickness of the passive piezoelectric plastic film is a multiple of the thickness of the active piezoelectric plastic film.
  • an ultrasound transducer contains a support body 2, a transmission layer 4 and two ⁇ / 4 adaptation layers, the second A / 4 adaptation layer also being provided as a reception layer 6.
  • the first ⁇ / 4 adaptation layer 8 faces the transmission layer 4 and is also provided as backing for the reception layer 6. All layers can preferably be connected to one another over a large area in hybrid technology.
  • the thicknesses of the matching layers are each a quarter wavelength at a predetermined resonance frequency. With a resonance frequency of approximately 10 MHz, the thickness of the matching layers is, for example, 55 ⁇ m and, for a resonance frequency of approximately 2 MHz, for example, 275 ⁇ m.
  • a material with a relatively high dielectric constant and high sound impedance serves as the transmission layer 4.
  • a transmission layer 4 made of lead zirconate titanate PZT or lead metanobate Pb (N0 3 ) is preferred.
  • the two matching layers have the task of matching different acoustic impedances to each other with little reflection.
  • the material for the first adaptation layer 8 can be, for example, porcelain, preferably quartz glass, in particular a glass-like material (Macor), and for the second adaptation layer one can use, for example, polyvinyl chloride PVC, in particular polyvinylidene fluoride PVDF.
  • the polyvinylidene fluoride PVDF layer must be polarized and provided with electrical connections which, like the electrical connections of the transmission layer, are not shown in FIG. 1.
  • This design provides a broadband and sensitive ultrasound transducer, which is used in medicine in particular because of its almost low-reflection coupling between tissue and ultrasound transducer.
  • the receiving layer 6 consists of a stack of thin piezoelectric plastic films 10 electrically connected in series. These piezoelectric plastic films 10 are each polarized in the same direction and the thickness of the stack is a quarter wavelength at a predetermined resonance frequency. Up to a frequency of, for example, 4 MHz, the stack can expediently consist of, for example, 25 ⁇ m thick plastic films 10, while for higher frequencies the stack can be constructed of, for example, 9 ⁇ m thick plastic films 10.
  • polyvinyl chloride PVC in particular polyvinylidene fluoride PVDF, can be used as the material for the piezoelectric plastic films of the receiving layer 6.
  • This configuration of the receiving layer 6 enables the thin, for example 9 ⁇ m to 25 ⁇ m thick, piezoelectric plastic films to be polarized very well.
  • the receiving layer 6 consists of an active piezoelectric plastic film 12 and a thicker passive piezoelectric plastic film 14.
  • the thickness of the passive piezoelectric plastic film 14 of the receiving layer 6 is a multiple, for example 2 to 15 times, of the thickness of the active piezoelectric plastic film 12 of the receiving layer 6.
  • the active piezoelectric plastic film 12, which is for example 25 ⁇ m thick, is arranged on the first ⁇ / 4 matching layer 8 and the passive piezoelectric plastic film 14 faces the load.
  • This configuration of the receiving layer 6 results in a broadband and sensitive ultrasound transducer with a comparatively large capacity and a correspondingly low internal impedance with comparatively small spatial dimensions.

Abstract

1. An ultrasonic transducer having a supporting body (2), a transmitting layer (4) of a material with a relatively high dielectric constant and high acoustic impedance and a first lambda/4 coupling layer (8) that faces the transmitting layer (4), and a second lambda/4 coupling layer that faces a load, characterised in that the second lambda/4 coupling layer also serves as a receiving layer (6) and that the first lambda/4 coupling layer (8) also serves as backing for the receiving layer (6).

Description

Die Erfindung bezieht sich auf einen Ultraschallwandler mit einem Tragkörper, einer Sendeschicht aus einem Material mit verhältnismäßig hoher dielektrischer Konstante und einer ersten λ/4-Anpassungsschicht, die der Sendeschicht zugewandt ist sowie einer zweiten λ/4-Anpassungsschicht, die einer Last zugewandt ist.The invention relates to an ultrasonic transducer with a support body, a transmission layer made of a material with a relatively high dielectric constant and a first λ / 4 adaptation layer, which faces the transmission layer, and a second λ / 4 adaptation layer, which faces a load.

In der medizinischen Ultraschalldiagnostik und der zerstörungsfreien Werkstoffprüfung werden Ultraschallbreitbandwandler eingesetzt. Insbesondere die medizinische Anwendung, wo mit möglichst geringen Verlusten eine Kopplung zwischen Gewebe und Schallwandler vorgenommen werden muß, erfordert eine Verbesserung der elektromechanischen und akustischen Eigenschaften dieser Wandlersysteme.Ultrasonic broadband converters are used in medical ultrasound diagnostics and non-destructive material testing. In particular, the medical application, where a coupling between tissue and sound transducer must be carried out with the lowest possible losses, requires an improvement in the electromechanical and acoustic properties of these transducer systems.

Es ist ein Ultraschallwandler bekannt, dessen Keramikwandler durch zwei A/4-Anpassungsschichten an ein Lastmedium Gewebe oder Wasser angepaßt wird. Dieses Wandlersystem enthält ein Backing aus Epoxidharz mit einer akustischen Impedanz von 3x106 Pas/m, einen Keramikwandler, eine erste λ/4-Anpassungsschicht aus Glas mit einer akustischen Impedanz von 10x106 Pas/m und eine zweite 1/4-Anpassungsschicht aus Polyacryl oder aus Epoxidharz mit einer akustischen Impedanz von 3x106 Pas/m. Der Keramikwandler ist auf einem Backing angeordnet. Die Glasplatte als erste Anpassungsschicht ist mit einem Adhäsionskleber sehr niedriger Viskosität vorgenommen, so daß Klebeschichten im Bereich von etwa 2 µm vorliegen. Das Epoxidharz, als zweite Anpassungsschicht ist direkt auf die erste Anpassungsschicht aufgegossen (Experimentelle Untersuchungen zum Aufbau von Ultraschallbreitbandwandlern, Biomedizinische Technik, Band 27, Heft 7 bis 8, 1982, Seiten 182 bis 185). Durch diese doppelte λ/4-Anpassung erreicht man nur eine Verbesserung der Empfindlichkeit und der Bandbreite der Keramiksendeschicht. Die Bandbreite dieses Ultraschallwandler beträgt etwa 60 bis 70 % der Mittenfrequenz.An ultrasonic transducer is known, the ceramic transducer of which is adapted to a load medium, tissue or water, by means of two A / 4 adaptation layers. This transducer system contains an epoxy resin backing with an acoustic impedance of 3x10 6 Pas / m, a ceramic transducer, a first λ / 4 matching layer made of glass with an acoustic impedance of 10x10 6 Pas / m and a second 1/4 matching layer made of polyacrylic or made of epoxy resin with an acoustic impedance of 3x10 6 Pas / m. The ceramic converter is arranged on a backing. The glass plate as the first adjustment layer is very adhesive with an adhesive low viscosity, so that adhesive layers are in the range of about 2 microns. The epoxy resin, as the second adaptation layer, is poured directly onto the first adaptation layer (experimental studies on the construction of ultrasound broadband transducers, biomedical engineering, volume 27, issues 7 to 8, 1982, pages 182 to 185). This double λ / 4 adaptation only improves the sensitivity and the bandwidth of the ceramic transmission layer. The bandwidth of this ultrasonic transducer is approximately 60 to 70% of the center frequency.

Außerdem ist ein Ultraschallwandler bekannt, der eine Sendeschicht aus einem Material mit verhältnismäßig hoher dielektrischer Konstante und hoher Schallimpedanz und einer Empfangsschicht aus einem Material mit verhältnismäßig niedriger dielektrischer Konstante und niedriger Schallimpedanz, die in Hybridtechnik flächig aufeinanderliegend verbunden sind. Die Sendeschicht besteht beispielsweise aus Blei-Zirkonat-Titanat PZT oder Bleimetaniobat Pb(NG3). Die Empfangsschicht besteht demgegenüber aus einer piezoelektrischen Kunststoffolie mit einer akustischen Impedanz von etwa 3x106 Pas/m beispielsweise Polyvinyliden-Fluorid PVDF oder Polycarbonat oder Polyvinylchlorid PVC. Die Empfangsschicht soll zugleich Anpassungsschicht für den Sendefall sein (deutsche Patentschrift 29 14 031). Die Ausbildung der Empfangsschicht als Anpassungsschicht zur Anpassung an Körpergewebe kann aber nur als einfache λ/4-Schicht ausgebildet sein. Die Anpassungsschicht für den Sendefall ist jedoch hier keine einfache /4-Anpassung. Bei einfacher 1/4-Anpassung ergibt sich aus der Theorie eine Anpassungsschicht mit einer akustischen Impedanz von etwa 7x10 6 Pas/m.In addition, an ultrasonic transducer is known which has a transmission layer made of a material with a relatively high dielectric constant and high sound impedance and a reception layer made of a material with a relatively low dielectric constant and low sound impedance, which are connected flatly in hybrid technology. The transmission layer consists, for example, of lead zirconate titanate PZT or lead metaniobate Pb (NG 3 ). In contrast, the receiving layer consists of a piezoelectric plastic film with an acoustic impedance of approximately 3 × 10 6 Pas / m, for example polyvinylidene fluoride PVDF or polycarbonate or polyvinyl chloride PVC. The receiving layer should also be an adaptation layer for the transmission case (German patent specification 29 14 031). The formation of the receiving layer as an adaptation layer for adaptation to body tissue can, however, only be designed as a simple λ / 4 layer. However, the adaptation layer for the transmission case is not a simple / 4 adaptation. With a simple 1/4 adjustment, the theory results in an adjustment layer with an acoustic impedance of about 7x10 6 Pas / m.

Der Erfindung liegt nun die Aufgabe zugrunde, einen Ultraschallwandler mit einem effektiven breitbandigen Sender und einem empfindlichen und breitbandigen Empfänger anzugeben. Außerdem soll das keramische Schwingermaterial der Sendeschicht breitbandig an Gewebe oder Wasser angepaßt werden.The invention is based on the object of specifying an ultrasonic transducer with an effective broadband transmitter and a sensitive and broadband receiver. In addition, the ceramic vibrating material of the transmission layer is to be broadband adapted to tissue or water.

Diese Aufgabe wird erfindungsgemäß gelöst mit den kennzeichnenden Merkmalen des Anspruchs 1. Dadurch, daß die zweite Ä/4-Anpassungsschicht zugleich als Empfangsschicht und die erste l/4-Anpassungsschicht zugleich als Backing für die Empfangsschicht vorgesehen ist, erhält man einen Ultraschallwandler, dessen Sendeschicht reflexionsarm an eine Last angepaßt ist und dessen Empfangsschicht außergewöhnlich empfindlich und breitbandig ist.This object is achieved according to the invention with the characterizing features of claim 1. Because the second λ / 4 adaptation layer is simultaneously provided as a receiving layer and the first 1/4 adaptation layer is also provided as backing for the reception layer, an ultrasound transducer, the transmission layer of which is obtained is adapted to a load with low reflection and its receiving layer is exceptionally sensitive and broadband.

Bei einer besonders vorteilhaften Ausführungsform des Ultraschallwandlers besteht die Empfangsschicht aus einem Stapel dünner elektrisch in Serie geschalteter piezoelektrischer Kunststoffolien. Durch diese Gestaltung der Empfangsschicht kann man die einzelnen piezoelektrischen Kunststoffolien aufgrund der geringen Dicke einfacher polarisieren.In a particularly advantageous embodiment of the ultrasound transducer, the receiving layer consists of a stack of thin piezoelectric plastic films that are electrically connected in series. This design of the receiving layer makes it easier to polarize the individual piezoelectric plastic films due to the small thickness.

In einer weiteren vorteilhaften Ausführungsform des Ultraschallwandlers besteht die Empfangsschicht aus einer aktiven und einer passiven piezoelektrischen Kunststoffolie, wobei die aktive piezoelektrische Kunststoffolie auf der ersten Anpassungsschicht angeordnet ist und die passive piezoelektrische Kunststofffolie der Last zugewandt ist. Die Dicke der passiven piezoelektrischen Kunststoffolie beträgt ein Vielfaches der Dicke der aktiven piezoelektrischen Kunststoffolie. Durch diese Gestaltung der Empfangsschicht erhält man einen breitbandigen, empfindlichen Ultraschallwandler mit verhältnismäßig großer Kapazität und entsprechend geringer Innenimpedanz.In a further advantageous embodiment of the ultrasonic transducer, the receiving layer consists of an active and a passive piezoelectric plastic film, the active piezoelectric plastic film being arranged on the first adaptation layer and the passive piezoelectric plastic film facing the load. The thickness of the passive piezoelectric plastic film is a multiple of the thickness of the active piezoelectric plastic film. This configuration of the receiving layer gives a broadband, sensitive ultrasonic transducer with a relatively large capacity and a correspondingly low internal impedance.

Zur weiteren Erläuterung wird auf die Zeichnung Bezug genommen, in der ein Ausführungsbeispiel eines Ultraschallwandlers nach der Erfindung schematisch veranschaulicht ist.

  • Figur 1 zeigt einen Ultraschallwandler gemäß der Erfindung und in
  • Figur 2 ist eine vorteilhafte Ausführungsform der Erfindung dargestellt.
  • Figur 3 veranschaulicht eine weitere Ausführungsform der Erfindung.
For further explanation, reference is made to the drawing, in which an embodiment of an ultrasonic transducer according to the invention is schematically illustrated.
  • Figure 1 shows an ultrasonic transducer according to the invention and in
  • Figure 2 shows an advantageous embodiment of the invention.
  • Figure 3 illustrates another embodiment of the invention.

In der Ausführungsform nach Figur 1 enthält ein Ultraschallwandler einen Tragkörper 2, eine Sendeschicht 4 und zwei λ/4-Anpassungsschichten, wobei die zweite A/4-Anpassungsschicht zugleich als Empfangsschicht 6 vorgesehen ist. Die erste Ä/4-Anpassungsschicht 8 ist der Sendeschicht 4 zugewandt und ist zugleich als Backing für die Empfangsschicht 6 vorgesehen. Sämtliche Schichten können vorzugsweise großflächig in Hybridtechnik miteinander verbunden sein. Die Dicken der Anpassungsschichten betragen jeweils bei einer vorbestimmten Resonanzfrequenz eine viertel Wellenlänge. Bei einer Resonanzfrequenz von etwa 10 MHz beträgt die Dicke der Anpassungsschichten beispielsweise 55 µm und bei einer Resonanzfrequenz von etwa 2 MHz beispielsweise 275 µm. Als Sendeschicht 4 dient ein Material mit relativ hoher dielektrischer Konstante und hoher Schallimpedanz, beispielsweise ein Piezokeramik-Material. Zu bevorzugen ist hierbei eine Sendeschicht 4 aus Blei-Zirkonat-Titanat PZT oder Bleimetaniobat Pb(N03). Die beiden Anpassungsschichten haben die Aufgabe, unterschiedliche akustische Impedanzen reflexionsarm aneinander anzupassen. Hier muß man die Sendeschicht aus Blei-Zirkonat-Titanat PZT mit einer akustischen Impedanz von ungefähr 30x106 Pas/m einer Last, beispielsweise Gewebe oder Wasser mit einer akustischen Impedanz von 1,5x106Pas/m, anpassen. Um eine optimale reflektionsarme Anpassung zu erreichen, ist aus der Theorie die mehrstufige Transformation mit zwei 1/4-Anpassungsschichten bekannt, bei der ein zulässiger Eingangsreflexionsfaktor nach dem Tschebyscheff-Verlauf approximiert wird. Hieraus ergibt sich für die erste λ/4-Anpassungsschicht 8 eine akustische Impedanz von etwa 14x 106 Pas/m und für die zweite 2/4-Anpassungsschicht eine akustische Impedanz von etwa 4x106 Pas/m. Als Material für die erste Anpassungsschicht 8 kann man beispielsweise Porzellan, vorzugsweise Quarzglas, insbesondere einen glasartigen Stoff (Macor) und für die zweite Anpassungsschicht kann man beispielsweise Polyvinylchlorid PVC, insbesondere PolyvinylidenFluorid PVDF, verwenden.In the embodiment according to FIG. 1, an ultrasound transducer contains a support body 2, a transmission layer 4 and two λ / 4 adaptation layers, the second A / 4 adaptation layer also being provided as a reception layer 6. The first λ / 4 adaptation layer 8 faces the transmission layer 4 and is also provided as backing for the reception layer 6. All layers can preferably be connected to one another over a large area in hybrid technology. The thicknesses of the matching layers are each a quarter wavelength at a predetermined resonance frequency. With a resonance frequency of approximately 10 MHz, the thickness of the matching layers is, for example, 55 μm and, for a resonance frequency of approximately 2 MHz, for example, 275 μm. A material with a relatively high dielectric constant and high sound impedance, for example a piezoceramic material, serves as the transmission layer 4. A transmission layer 4 made of lead zirconate titanate PZT or lead metanobate Pb (N0 3 ) is preferred. The two matching layers have the task of matching different acoustic impedances to each other with little reflection. Here you have to adapt the transmitting layer made of lead-zirconate-titanate PZT with an acoustic impedance of approximately 30x10 6 Pas / m to a load, for example tissue or water with an acoustic impedance of 1.5x10 6 Pas / m. In order to achieve an optimal low-reflection adjustment, multi-stage transformation with two 1/4 adjustment layers is known from the theory, in which a permissible input reflection factor is approximated according to the Chebyshev curve. This results in an acoustic impedance of approximately 14 × 10 6 Pas / m for the first λ / 4 matching layer 8 and an acoustic impedance of approximately 4x10 6 Pas / m for the second 2/4 matching layer. The material for the first adaptation layer 8 can be, for example, porcelain, preferably quartz glass, in particular a glass-like material (Macor), and for the second adaptation layer one can use, for example, polyvinyl chloride PVC, in particular polyvinylidene fluoride PVDF.

Damit die zweite Anpassungsschicht zugleich als Empfangsschicht 6 dient, muß man die Polyvinyliden- Fluorid PVDF-Schicht polarisieren und mit elektrischen Anschlüssen versehen, die, wie die elektrischen Anschlüsse der Sendeschicht, in der Figur 1 nicht dargestellt sind.So that the second adaptation layer also serves as the receiving layer 6, the polyvinylidene fluoride PVDF layer must be polarized and provided with electrical connections which, like the electrical connections of the transmission layer, are not shown in FIG. 1.

Durch diese Gestaltung erhält man einen breitbandigen und empfindlichen Ultraschallwandler, der insbesondere wegen seiner annähernd reflexionsarmen Kopplung zwischen Gewebe und Ultraschallwandler in der Medizin Anwendung findet.This design provides a broadband and sensitive ultrasound transducer, which is used in medicine in particular because of its almost low-reflection coupling between tissue and ultrasound transducer.

In einer besonders vorteilhaften Ausführungsform nach Figur 2 besteht die Empfangsschicht 6 aus einem Stapel dünner elektrisch in Serie geschalteter piezoelektrischer Kunststoffolien 10. Diese piezoelektrischen Kunststoffolien 10 sind jeweils in derselben Richtung polarisiert und die Dicke des Stapels beträgt eine viertel Wellenlänge bei einer vorbestimmten Resonanzfrequenz. Bis zu einer Frequenz von beispielsweise 4 MHz kann der Stapel zweckmäßig aus beispielsweise 25 µm dicken Kunststoffolien 10 bestehen, während für höhere Frequenzen der Stapel aus beispielsweise 9 pm dicken Kunststoffolien 10 aufgebaut sein kann. Als Material für die piezoelekrischen Kunststoffolien der Empfangsschicht 6 kann man beispielsweise Polyvinylchlorid PVC, insbesondere Polyvinyliden-Fluorid PVDF, verwenden.In a particularly advantageous embodiment according to FIG. 2, the receiving layer 6 consists of a stack of thin piezoelectric plastic films 10 electrically connected in series. These piezoelectric plastic films 10 are each polarized in the same direction and the thickness of the stack is a quarter wavelength at a predetermined resonance frequency. Up to a frequency of, for example, 4 MHz, the stack can expediently consist of, for example, 25 μm thick plastic films 10, while for higher frequencies the stack can be constructed of, for example, 9 μm thick plastic films 10. For example, polyvinyl chloride PVC, in particular polyvinylidene fluoride PVDF, can be used as the material for the piezoelectric plastic films of the receiving layer 6.

Durch diese Gestaltung der Empfangsschicht 6 kann man die dünnen, beispielsweise 9 um bis 25 um dicken, piezoelektrischen Kunststoffolien sehr gut polarisieren.This configuration of the receiving layer 6 enables the thin, for example 9 μm to 25 μm thick, piezoelectric plastic films to be polarized very well.

In einer weiteren Ausführungsform nach Figur 3 besteht die Empfangsschicht 6 aus einer aktiven piezoelektrischen Kunststoffolie 12 und einer dickeren passiven piezoelektrischen Kunststoffolie 14. Die Dicke der passiven piezoelektrischen Kunststoffolie 14 der Empfangsschicht 6 beträgt ein Vielfaches, beispielsweise 2 bis 15fache, der Dicke der aktiven piezoelektrischen Kunststoffolie 12 der Empfangsschicht 6. Die aktive piezoelektrische Kunststoffolie 12, die beispielsweise 25 um dick ist, ist auf die erste λ/4-Anpassungsschicht 8 angeordnet und die passive piezoelektrische Kunststoffolie 14 ist der Last zugewandt. Auch in dieser Ausführungsform verwendet man als Material für die piezoelektrischen Kunststoffolien der Empfangsschicht 6 beispielsweise Polyvinylchlorid PVC, insbesondere Polyvinyliden-Fluorid PVDF. Sowohl die aktive als auch die passive piezoelektrische Kunststoffolie 12 bzw. 14 bestehen aus demselben Material, wobei die aktive piezoelektrische Kunststoffolie 12 polarisiert ist.In a further embodiment according to FIG. 3, the receiving layer 6 consists of an active piezoelectric plastic film 12 and a thicker passive piezoelectric plastic film 14. The thickness of the passive piezoelectric plastic film 14 of the receiving layer 6 is a multiple, for example 2 to 15 times, of the thickness of the active piezoelectric plastic film 12 of the receiving layer 6. The active piezoelectric plastic film 12, which is for example 25 µm thick, is arranged on the first λ / 4 matching layer 8 and the passive piezoelectric plastic film 14 faces the load. Also in this embodiment, the material used for the piezoelectric plastic films Receiving layer 6, for example polyvinyl chloride PVC, in particular polyvinylidene fluoride PVDF. Both the active and the passive piezoelectric plastic film 12 or 14 consist of the same material, the active piezoelectric plastic film 12 being polarized.

Durch diese Gestaltung der Empfangsschicht 6 erhält man einen breitbandigen und empfindlichen Ultraschallwandler mit verhältnismäßig großer Kapazität und entsprechend geringer Innenimpedanz bei verhältnismäßig kleinen räumlichen Abmessungen.This configuration of the receiving layer 6 results in a broadband and sensitive ultrasound transducer with a comparatively large capacity and a correspondingly low internal impedance with comparatively small spatial dimensions.

Claims (10)

1. Ultraschallwandler mit einem Tragkörper (2), einer Sendeschicht (4) aus einem Material mit verhältnismäßig hoher dielektrischer Konstante und hoher akustischer Impedanz und einer ersten A/4-Anpassungsschicht (8), die der Sendeschicht (4) zugewandt ist sowie einer zweiten λ/4- Anpassungsschicht, die einer Last zugewandt ist, dadurch gekennzeichnet , daß die zweite λ/4-Anpassungsschicht zugleich als Empfangsschicht (6) vorgesehen ist und daß die erste λ/4-Anpassungsschicht (8) zugleich als Backing für die Empfangsschicht (6) vorgesehen ist.1. Ultrasonic transducer with a support body (2), a transmission layer (4) made of a material with a relatively high dielectric constant and high acoustic impedance and a first A / 4 matching layer (8) which faces the transmission layer (4) and a second λ / 4 matching layer facing a load, characterized in that the second λ / 4 matching layer is also provided as a receiving layer (6) and that the first λ / 4 matching layer (8) is also used as a backing for the receiving layer ( 6) is provided. 2. Ultraschallwandler nach Anspruch 1, dadurch gekennzeichnet , daß die Empfangsschicht (6) aus einem Stapel dünner elektrisch in Serie geschalteter piezoelektrischer Kunststoffolien (10) besteht.2. Ultrasonic transducer according to claim 1, characterized in that the receiving layer (6) consists of a stack of thin electrically connected in series piezoelectric plastic films (10). 3. Ultraschallwandler nach Anspruch 1, dadurch gekennzeichnet , daß die Empfangsschicht (6) aus einer aktiven piezoelektrischen Kunststoffolie (12) und einer passiven piezoelektrischen Kunststofffolie (14) besteht.3. Ultrasonic transducer according to claim 1, characterized in that the receiving layer (6) consists of an active piezoelectric plastic film (12) and a passive piezoelectric plastic film (14). 4. Ultraschallwandler nach Anspruch 3, dadurch gekennzeichnet , daß die aktive piezoelektrische Kunststoffolie (12) der Empfangsschicht (6) auf dem harten Backing angeordnet ist und die passive piezoelektrische Kunststoffolie (14) der Empfangsschicht (6) der Last zugewandt ist.4. Ultrasonic transducer according to claim 3, characterized in that the active piezoelectric plastic film (12) of the receiving layer (6) is arranged on the hard backing and the passive piezoelectric plastic film (14) of the receiving layer (6) faces the load. 5. Ultraschallwandler nach Anspruch 3, dadurch gekennzeichnet , daß die Dicke der passiven piezoelektrischen Kunststoffolie (14) der Empfangsschicht (6) ein Vielfaches der Dicke der aktiven piezoelektrischen Kunststoffolie (12) der Empfangsschicht (6) beträgt.5. Ultrasonic transducer according to claim 3, characterized in that the thickness of the passive piezoelectric plastic film (14) Receiving layer (6) is a multiple of the thickness of the active piezoelectric plastic film (12) of the receiving layer (6). 6. Ultraschallwandler nach Anspruch 1, dadurch gekennzeichnet , daß die Sendeschicht (4) aus Blei-Zirkonat-Titanat PZT oder Blei-Metaniobat Pb(NG3) besteht.6. Ultrasonic transducer according to claim 1, characterized in that the transmission layer (4) consists of lead zirconate titanate PZT or lead metaniobate Pb (NG 3 ). 7. Ultraschallwandler nach Anspruch 1 und 6, dadurch gekennzeichnet , daß die zweite λ/4-Anpassungsschicht eine akustische Impedanz von etwa 4x106
Figure imgb0001
hat und die erste λ/4-Anpassungsschicht (8) eine akustische Impedanz von etwa 14x10 6
Figure imgb0002
 hat.7. Ultrasonic transducer according to claim 1 and 6, characterized in that the second λ / 4 matching layer has an acoustic impedance of about 4x10 6th
Figure imgb0001
 and the first λ / 4 matching layer (8) has an acoustic impedance of approximately 14x10 6
Figure imgb0002
 has . 8. Ultraschallwandler nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet , daß die Empfangsschicht (6) aus piezoelektrischen Kunststofffolien (10, 12, 14) besteht.8. Ultrasonic transducer according to one of claims 1 to 3, characterized in that the receiving layer (6) consists of piezoelectric plastic films (10, 12, 14). 9. Ultraschallwandler nach Anspruch 8, dadurch gekennzeichnet , daß die piezoelektrischen Kunststoffolien (10, 12, 14) der Empfangsschicht (6) aus Polyvinyliden-Fluorid PVDF oder Polyvinylchlorid PVC bestehen.9. Ultrasonic transducer according to claim 8, characterized in that the piezoelectric plastic films (10, 12, 14) of the receiving layer (6) consist of polyvinylidene fluoride PVDF or polyvinyl chloride PVC. 10. Ultraschallwandler nach Anspruch 1, dadurch gekennzeichnet , daß die erste λ/4-Anpassungsschicht aus Quarzglas oder einem glasartigen Stoff oder Porzellan besteht.10. Ultrasonic transducer according to claim 1, characterized in that the first λ / 4 matching layer consists of quartz glass or a glass-like material or porcelain.
EP84102147A 1983-03-15 1984-02-29 Ultrasonic transducer Expired EP0118837B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84102147T ATE35338T1 (en) 1983-03-15 1984-02-29 ULTRASONIC TRANSDUCER.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3309236 1983-03-15
DE19833309236 DE3309236A1 (en) 1983-03-15 1983-03-15 ULTRASONIC CONVERTER

Publications (3)

Publication Number Publication Date
EP0118837A2 true EP0118837A2 (en) 1984-09-19
EP0118837A3 EP0118837A3 (en) 1985-05-15
EP0118837B1 EP0118837B1 (en) 1988-06-22

Family

ID=6193523

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84102147A Expired EP0118837B1 (en) 1983-03-15 1984-02-29 Ultrasonic transducer

Country Status (5)

Country Link
EP (1) EP0118837B1 (en)
JP (1) JPS59161800U (en)
AT (1) ATE35338T1 (en)
CA (1) CA1252558A (en)
DE (2) DE3309236A1 (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0166976A1 (en) * 1984-06-14 1986-01-08 Siemens Aktiengesellschaft Ultrasonic transducer system
DE3501808A1 (en) * 1985-01-21 1986-07-24 Siemens AG, 1000 Berlin und 8000 München ULTRASONIC CONVERTER
EP0212352A1 (en) * 1985-08-09 1987-03-04 Siemens Aktiengesellschaft Ultrasonic generator
EP0421286A2 (en) * 1989-10-03 1991-04-10 Richard Wolf GmbH Piezoelectric transducer
EP0451517A1 (en) * 1990-04-11 1991-10-16 Hewlett-Packard Company Acoustic image acquisition
US5263004A (en) * 1990-04-11 1993-11-16 Hewlett-Packard Company Acoustic image acquisition using an acoustic receiving array with variable time delay
DE19714606A1 (en) * 1997-04-09 1998-10-15 Itt Mfg Enterprises Inc Ultra sound transmitter and receiver for motor vehicle distance warning system
WO1999032858A1 (en) * 1997-12-23 1999-07-01 Simmonds Precision Products, Inc. Ultrasonic liquid gauging system
EP2295154A1 (en) * 2009-09-15 2011-03-16 Fujifilm Corporation Ultrasonic transducer, ultrasonic probe and producing method
US20230134074A1 (en) * 2021-10-28 2023-05-04 Baker Hughes, A Ge Company, Llc Ultrasonic transducer for flow measurement

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3430186A1 (en) * 1984-08-16 1986-02-27 Siemens AG, 1000 Berlin und 8000 München METHOD FOR PRODUCING A POROUS PIEZOELECTRIC MATERIAL AND MATERIAL PRODUCED BY THIS METHOD
DE3839057A1 (en) * 1988-11-18 1990-05-23 Fraunhofer Ges Forschung Array-type probe
DE102007027277A1 (en) * 2007-06-11 2008-12-18 Endress + Hauser Flowtec Ag ultrasonic sensor
US20100256497A1 (en) * 2007-11-21 2010-10-07 Kenji Ohnuma Oscillator for ultrasonic wave reception, its manufacturing method, ultrasonic wave probe and ultrasonic wave medical diagnostic imaging system

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4016530A (en) * 1975-06-02 1977-04-05 Goll Jeffrey H Broadband electroacoustic converter
EP0021534A1 (en) * 1979-06-25 1981-01-07 Koninklijke Philips Electronics N.V. Acoustic transducer
US4427912A (en) * 1982-05-13 1984-01-24 Ausonics Pty. Ltd. Ultrasound transducer for enhancing signal reception in ultrasound equipment

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57141199A (en) * 1981-02-25 1982-09-01 Aloka Co Ltd Ultrasonic wave probe

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4016530A (en) * 1975-06-02 1977-04-05 Goll Jeffrey H Broadband electroacoustic converter
EP0021534A1 (en) * 1979-06-25 1981-01-07 Koninklijke Philips Electronics N.V. Acoustic transducer
US4427912A (en) * 1982-05-13 1984-01-24 Ausonics Pty. Ltd. Ultrasound transducer for enhancing signal reception in ultrasound equipment

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Biomedizinische Technik, Bd. 27 Heft 7 Seiten 183-184 *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0166976A1 (en) * 1984-06-14 1986-01-08 Siemens Aktiengesellschaft Ultrasonic transducer system
DE3501808A1 (en) * 1985-01-21 1986-07-24 Siemens AG, 1000 Berlin und 8000 München ULTRASONIC CONVERTER
US4672591A (en) * 1985-01-21 1987-06-09 Siemens Aktiengesellschaft Ultrasonic transducer
EP0212352A1 (en) * 1985-08-09 1987-03-04 Siemens Aktiengesellschaft Ultrasonic generator
US4718421A (en) * 1985-08-09 1988-01-12 Siemens Aktiengesellschaft Ultrasound generator
EP0421286A3 (en) * 1989-10-03 1992-06-03 Richard Wolf Gmbh Piezoelectric transducer
EP0421286A2 (en) * 1989-10-03 1991-04-10 Richard Wolf GmbH Piezoelectric transducer
EP0451517A1 (en) * 1990-04-11 1991-10-16 Hewlett-Packard Company Acoustic image acquisition
US5263004A (en) * 1990-04-11 1993-11-16 Hewlett-Packard Company Acoustic image acquisition using an acoustic receiving array with variable time delay
DE19714606A1 (en) * 1997-04-09 1998-10-15 Itt Mfg Enterprises Inc Ultra sound transmitter and receiver for motor vehicle distance warning system
WO1999032858A1 (en) * 1997-12-23 1999-07-01 Simmonds Precision Products, Inc. Ultrasonic liquid gauging system
EP2295154A1 (en) * 2009-09-15 2011-03-16 Fujifilm Corporation Ultrasonic transducer, ultrasonic probe and producing method
US20230134074A1 (en) * 2021-10-28 2023-05-04 Baker Hughes, A Ge Company, Llc Ultrasonic transducer for flow measurement
US11806749B2 (en) * 2021-10-28 2023-11-07 Baker Hughes, A Ge Company, Llc Ultrasonic transducer for flow measurement

Also Published As

Publication number Publication date
DE3472318D1 (en) 1988-07-28
EP0118837B1 (en) 1988-06-22
JPH0453117Y2 (en) 1992-12-14
DE3309236A1 (en) 1984-09-20
JPS59161800U (en) 1984-10-30
EP0118837A3 (en) 1985-05-15
CA1252558A (en) 1989-04-11
ATE35338T1 (en) 1988-07-15

Similar Documents

Publication Publication Date Title
DE3501808C2 (en)
EP0166976B1 (en) Ultrasonic transducer system
EP0118837B1 (en) Ultrasonic transducer
DE3611669C2 (en)
EP0017216B1 (en) Ultrasonic transducer
DE19635593C1 (en) Ultrasound transducer for diagnostic and therapeutic use
DE69430490T3 (en) Method for producing a transducer arrangement for imaging
DE602004004488T2 (en) Ultrasonic probe with conductive acoustic matching layer
DE4010294C2 (en)
DE3210925A1 (en) ULTRASONIC CONVERTER
EP0173864B1 (en) Porous matching layer in an ultrasonic applicator
DE69936507T2 (en) CATHETER WITH RINGELY MOUNTED ULTRASOUND TRANSFORMERS
DE60306367T2 (en) ULTRASONIC CONVERTER WITH MEMBRANE
DE3124919C2 (en) Transducer arrangement for ultrasonic scanning devices
DE3331955C2 (en) Ultrasonic transducer
DE10230129A1 (en) Ultrasound measuring value converter used for medical imaging comprises a number of elements each consisting of piezoelectric layer having a metallized surface, and an acoustic accommodating layer of silicon lying next to metallized surface
DE112007002645T5 (en) ultrasound probe
DE3526488A1 (en) ULTRASONIC CONVERTER WITH PIEZOELECTRIC COMPOSITE MATERIAL
DE112007001957T5 (en) Sound transducer arrangement with low profile
DE3237358A1 (en) ELEMENT FOR ELASTIC SURFACE WAVES
DE19701334A1 (en) Transducer for medical imaging which transmits a first harmonic and predominantly receives second harmonics
DE3733776A1 (en) ULTRASONIC PROBE
DE60315286T2 (en) GROUP OF MEMBRANE ULTRASOUND TRANSFORMERS
EP0045989A2 (en) Acoustic impedance matching device
EP0166180B1 (en) Hydrophone

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT DE FR GB

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): AT DE FR GB

17P Request for examination filed

Effective date: 19850827

17Q First examination report despatched

Effective date: 19870422

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT DE FR GB

REF Corresponds to:

Ref document number: 35338

Country of ref document: AT

Date of ref document: 19880715

Kind code of ref document: T

REF Corresponds to:

Ref document number: 3472318

Country of ref document: DE

Date of ref document: 19880728

ET Fr: translation filed
GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19890425

Year of fee payment: 6

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19900131

Year of fee payment: 7

Ref country code: AT

Payment date: 19900131

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19900226

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19901101

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19910228

Ref country code: AT

Effective date: 19910228

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19911031

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST