Integrated composite acoustic transducer array

• US 5,629,578 A
• Filed: 03/20/1995
• Issued: 05/13/1997
• Est. Priority Date: 03/20/1995
• Status: Expired due to Term

• Current Assignee: AVX Corporation (Kyocera Corporation), Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: AVX Corporation (Kyocera Corporation), Martin Marietta Corporation
• Inventors: Ritter, Andrew P., Shah, Tushar K., Shankar, Natarajan, Winzer, Stephen R., Caldwell, Paul J., Bridger, Keith
• Primary Examiner(s): Budd, Mark O.
• Application Number:
  US08/406,601
• Time in Patent Office: 785 Days
• Field of Search: 310/334-337, 310/339, 310/348, 310/340, 310/346, 310/344
• US Class Current: 310/334
• CPC Class Codes: B06B 1/0614 for generating several frequencies
• CPC Class Codes: B06B 1/064 with multiple active layers
• CPC Class Codes: H10N 39/00 Integrated devices, or assemblies of multiple devices, comprising at least one piezoelectric, electrostrictive or magnetostrictive element covered by groups H10N30/00 – H10N35/00

Abstract

An improved transducer array includes a two-dimensional array of multilayer actuators, capable of producing very high displacement with low input voltage, integrally packaged with conditioning electronics. Preferred microcomposite actuators use multiple layers of stacked electrostrictive ceramics and conductive materials. The actuators are aligned in a two-dimensional array and can be integrated with the conditioning electronics in a variety of packaging systems. A preferred packaging system is a flexible high density interconnected multi-chip module which has the integrated circuit chips disposed in a substrate, interconnection layers disposed thereon and the multilayer composite actuators disposed on the surface of the interconnection structure. The actuators in this packaged array may be optionally addressed individually or in blocks, depending on the application intended.

Claims

1. An integrated, tunable, impedance-controllable and electronically addressable composite transducer assembly, comprising:

(a) a base;

(b) a plurality of multilayer actuators disposed on said base and forming a transducer array, each of said plurality of actuators having a plurality of alternating and juxtaposed layers of active material layers and internal conductive material layers which are electrically connected in parallel and mechanically connected in series and having a top surface and a bottom surface, where said plurality of actuators convert electrical energy to mechanical motion and reciprocally convert mechanical motion to electrical energy;

(c) a protective material encasing said plurality of actuators; and

(d) electronic means, being integrally connected to said base, and electrically connected to said plurality of actuators, for electrically measuring said electrical energy produced by said plurality of actuators and for producing electrical input to cause said plurality of actuators to move; and

wherein each actuator is individually fabricated to have a particular, selectable height, length, width, configuration, and a particular, selectable layer thickness; and

wherein each actuator is disposed on said base at a particular, selectable location; and

wherein each actuator has a particular, selectable direct current bias applied by said electronic means and a particular, selectable addressing applied by said electronic means;

so that the transducer array is tunable and impedance-controllable and electronically-addressable for selected operating frequencies and spatial configurations and directions of waveform beams of acoustic energy.

2. The integrated composite transducer assembly of claim 1, wherein said plurality of actuators are disposed on said base in a two-dimensional arrangement having rows and columns.

3. The integrated composite transducer assembly of claim 2, wherein said base is a material selected from the group consisting of ceramics, polymers, and composites.

4. The integrated composite transducer assembly of claim 3, wherein said base is a printed circuit board.

5. The integrated composite transducer assembly of claim 1, further comprising a top rigid structure overlying said plurality of actuators.

6. The integrated composite transducer assembly of claim 2, wherein said electronic means is electrically connected to said plurality of actuators individually.

7. The integrated composite transducer assembly of claim 2, wherein said electronic means is electrically connected to said plurality of actuators in blocks.

8. The integrated composite transducer assembly of claim 2, wherein said electronic means comprises a high density interconnected multichip module and where said high density interconnected module replaces said base.

9. The integrated composite transducer assembly of claim 2, wherein said actuators comprise a material selected from the group consisting of electrostrictive, piezoelectric, and magnetostrictive.

10. The integrated composite transducer assembly of claim 9, wherein said actuators have a height between about 0.1 mm and 20 mm, a length between about 0.1 mm and about 10 mm, and a width between about 0.1 mm and about 10 mm.

11. The integrated composite transducer assembly of claim 10, wherein said actuators in said assembly are spaced about 0.1 mm to about 100 mm from adjacent actuators.

12. The integrated composite transducer assembly of claim 9, wherein a plurality of sensors are placed in predetermined ones of the plurality of interstices between said actuators, and where said sensors comprise a selected one of the group consisting of fiber optic sensors, thermocouple sensors, actuators, electromagnetic sensors, and electrostatic sensors.

13. An integrated tunable, impedance-controllable and electronically-addressable composite transducer array, comprising:

(a) a base;

(b) a plurality of actuators disposed on said base, each actuator having a top surface and a bottom surface, as well as a length, width and height, each of said plurality of actuators further comprising a multilayer construction having

(i) two side layers of conductive material disposed on at least a portion of opposing sides of said actuator and extending from at least a portion of said top surface of said actuator to at least a portion of said bottom surface of said actuator;

(ii) an internal layer of actuating material extending the length, width and height of said actuator and internal to said top, bottom and side conductive layers;

(iii) a plurality of alternating internal conductive layers extending the width of said actuator and each alternating layer extending from a different one of said two side conductive layers than a next lower internal conductive layer and a next higher internal conductive layer, each of said plurality of alternating internal layers extending across at least a major portion of said length of said actuator but not making electrical contact with the other of said two side conductive layers from which each respective said plurality of internal conductive layers extends; and

wherein said plurality of actuators will actuate in response to electrical input and will produce electrical energy when acted upon by incoming acoustic energy; and

(c) electronic means electrically connected to said plurality of actuators for electrically measuring said electrical energy when said plurality of actuators are acted upon by incoming acoustic energy and for producing electrical input to cause actuation of said actuators and

wherein each actuator is individually fabricated to have a particular, selectable height, length, width, configuration and a particular, selectable layer thickness; and

wherein each actuator is disposed on said base at a particular, selectable location; and

wherein each actuator has a particular, selectable direct current bias applied by said electronic means and a particular selectable addressing applied by said electronic means;

so that the transducer array is tunable and impedance-controllable and electronically-addressable for selected operating frequencies and spatial configurations and directions of waveform beams of acoustic energy.

14. The composite transducer array of claim 13, where said transducer array is used in medical imaging.

15. The composite transducer array of claim 13, where said transducer array is used in underwater noise cancellation.

16. The composite transducer array of claim 13, wherein said electronic means comprises a high density interconnected multichip module and where said high density interconnected module replaces said base.

17. A high density interconnected, tunable, impedance-controllable and electronically-addressable composite transducer assembly, comprising:

a substrate having a top surface and at least one chipwell disposed therein;

a plurality of electronic components disposed in said at least one chipwell, at least some of said electronic components being integrated circuit chips having chip pads disposed thereon;

high density interconnecting means disposed over said substrate and plurality of electronic components for electrically interconnecting said electronic components;

a plurality of multilayer actuators each having a plurality of alternating and juxtaposed layers of active material layers and internal conductive material layers which are electrically connected in parallel and mechanically connected in series and being disposed on an upper surface of said high density interconnecting means and connected to said electronic components by said interconnecting means; and

a protective material disposed over and around said actuators for encapsulation; and

wherein each actuator is individually fabricated to have a particular, selectable height, length, width, configuration, and a particular, selectable layer thickness; and

wherein each actuator is disposed on said high density interconnecting means at a particular, selectable location; and

wherein each actuator has a particular, selectable direct current bias applied by said plurality of electronic components and a particular, selectable addressing applied by said plurality of electronic components;

so that the transducer assembly is tunable and impedance-controllable and electronically-addressable for selected operating frequencies and spatial configurations and directions of waveform beams of acoustic energy.

18. The integrated composite transducer assembly of claim 17, wherein said actuators comprise a material selected from the group consisting of electrostrictive, piezoelectric, and magnetostrictive.

19. The high density interconnected composite transducer assembly of claim 17 where said plurality of actuators are individually addressed and are disposed in a two-dimensional arrangement and each actuator being spaced from adjacent actuators by about 0.1 mm to about 100 mm.

20. The high density interconnected composite transducer assembly of claim 17 where said actuators where said actuators have a height between about 0.1 mm and 20 mm, a length between about 0.1 mm and about 10 mm, and a width between about 0.1 mm and about 10 mm.

21. The composite transducer array of claim 19, where said transducer array is used in medical imaging.

22. The composite transducer array of claim 19, where said transducer array is used in underwater noise cancellation.