Piezoelectric transducers using micro-dome arrays

Patent metadata

Field	Value
Publication number	US-10022750-B2
Application number	US-201514753707-A
Country	US
Kind code	B2
Filing date	Jun 29, 2015
Priority date	Feb 15, 2011
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

An ultrasonic piezoelectric transducer device includes a transducer array consisting of an array of vibrating elements, and a base to which the array of vibrating elements in the transducer array are attached. The base include integrated electrical interconnects for carrying driving signals and sensed signals between the vibrating elements and an external control circuit. The base can be an ASIC wafer that includes integrated circuitry for controlling the driving and processing the sensed signals. The interconnects and control circuits in the base fit substantially within an area below the array of multiple vibrating elements.

First claim

What is claimed is:

1. A piezoelectric transducer, comprising:
a support structure having a hole therein; and
a transducer element having an inner surface fixed to a first surface of the support structure, the transducer comprising a drive electrode, a reference electrode, a dielectric layer disposed between the drive electrode and the reference electrode, and a piezoelectric element disposed between the drive electrode and the reference electrode, the transducer element having an outer surface positioned to receive or generate pressure waves in an external medium, and wherein the drive electrode, the reference electrode, and the piezoelectric element each include a respective flexible portion and a respective stationary portion connected to the respective flexible portion,
wherein the flexible portions of the drive electrode, reference electrode, and piezoelectric element are suspended over the hole in the support structure and are curved in a first direction relative to the first surface of the support in the absence of an applied voltage between the drive electrode and the reference electrode and in the absence of an applied force that increases mechanical stress on the flexible portion, and wherein the flexible portions of the reference electrode, drive electrode, and piezoelectric element deflect in response to a driving voltage applied between the drive electrode and the reference electrode.

2. The piezoelectric transducer of claim 1 , wherein the support structure comprises a base having the first surface and a cavity formed in the first surface of the base to provide the hole.

3. The piezoelectric transducer of claim 1 , wherein the support structure comprises a base and a support between the base and the transducer element, and wherein the hole is formed through the support and the base spans the hole.

4. The piezoelectric transducer of claim 3 , wherein the support has a first side attached to a first surface of the base and a second side attached to the respective stationary portion of one of the drive electrode and reference electrode that is positioned closer to the first surface of the base.

5. The piezoelectric transducer of claim 3 , wherein the support is conductive.

6. The piezoelectric transducer of claim 4 , wherein the support comprises a metal ring.

7. The piezoelectric transducer of claim 6 , wherein the metal ring provides a eutectic bond between the base and the transducer element.

8. The piezoelectric transducer of claim 5 , wherein the support electrically connects the transducer element to integrated circuits formed in the base.

9. The piezoelectric transducer of claim 1 , wherein the outer surface includes a flexible film covering the drive electrode or reference electrode.

10. The piezoelectric transducer of claim 1 , wherein the transducer element is one of a plurality of substantially identical transducer elements, and wherein the support structure comprises a base and a plurality of supports between the base and the transducer elements.

11. The piezoelectric transducer of claim 10 , wherein the base comprises a layer that spans the plurality of supports.

12. The piezoelectric transducer of claim 11 , wherein the plurality of transducer elements are formed in a continuous layer that spans the plurality of supports.

13. The piezoelectric transducer of claim 12 , wherein each transducer element of the plurality of substantially identical transducer elements is supported by a respective support of the plurality of supports over the base.

14. The piezoelectric transducer of claim 10 , wherein the transducer element is one of a linear array of substantially identical transducer elements.

15. The piezoelectric transducer of claim 10 , wherein the transducer element is one of a two dimensional array of substantially identical transducer elements.

16. The piezoelectric transducer of claim 10 wherein the base includes integrated circuitry configured to independently sense pressure changes applied to the outer surface of the respective transducer elements of the plurality of transducer elements.

17. The piezoelectric transducer of claim 1 , wherein the drive electrode is positioned closer to support structure than the reference electrode.

18. The piezoelectric transducer of claim 1 , wherein the flexible portions of the drive electrode, reference electrode, and piezoelectric element are each curved away from the hole.

19. The piezoelectric transducer of claim 1 , wherein the flexible portions of the drive electrode, reference electrode, and piezoelectric element are each curved toward the hole.

20. The piezoelectric transducer of claim 1 , wherein the piezoelectric element includes a curved portion surrounded by a planar portion, and wherein the planar portion and a peripheral portion of the portion of the piezoelectric element are part of the stationary portion of the piezoelectric element.

Assignees

• Fujifilm Dimatix Inc

Inventors

• Bibl Andreas
• Law Hung-Fai Stephen
• Essen Kevin Von
• Ottosson Mats G

Classifications

• B06B2201/76

  Medical, dental · CPC title

• G10K11/32

  characterised by the shape of the source · CPC title

• B06B1/0662 Primary

  with an electrode on the sensitive surface · CPC title

• B06B1/0207

  Driving circuits (specially adapted for particular applications, see the relevant subclass, e.g. G01; circuits for steering transducer arrays G10K11/34; basic circuits H03) · CPC title

• B06B1/0622 Primary

  on one surface · CPC title