Piezoelectric element, piezoelectric actuator, and electronic apparatus

Patent metadata

Field	Value
Publication number	US-10424722-B2
Application number	US-201615354277-A
Country	US
Kind code	B2
Filing date	Nov 17, 2016
Priority date	Nov 27, 2015
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

Provided is a piezoelectric element containing no lead therein and having a satisfactory piezoelectric constant and a small dielectric loss tangent at room temperature (25° C.) In order to attain this, the piezoelectric element includes a substrate, a first electrode, a piezoelectric film, and a second electrode. The piezoelectric film contains barium zirconate titanate, manganese, and trivalent bismuth. The piezoelectric film satisfies 0.02≤x≤0.13, where x is a mole ratio of zirconium to the sum of zirconium and titanium. A manganese content is 0.002 moles or more and 0.015 moles or less for 1 mole of barium zirconate titanate, and a bismuth content is 0.00042 moles or more and 0.00850 moles or less for 1 mole of barium zirconate titanate.

First claim

What is claimed is:

1. A piezoelectric element, comprising:
a substrate;
a first electrode;
a piezoelectric film; and
a second electrode,
wherein the piezoelectric film comprises a perovskite metal oxide comprising barium zirconate titanate, manganese, and trivalent bismuth,
wherein the trivalent bismuth comprises trivalent bismuth positioned at an A site of the perovskite metal oxide,
wherein the piezoelectric film satisfies 0.02≤x≤0.13,
where x is a mole ratio of zirconium to a sum of zirconium and titanium,
wherein a manganese content is 0.002 moles to 0.015 moles for 1 mole of barium zirconate titanate, and
wherein a bismuth content is 0.00042 moles to 0.00850 moles for 1 mole of barium zirconate titanate, and
wherein a maximum film thickness T P nm of the piezoelectric film at a portion sandwiched between the first electrode and the second electrode is 10 μm or less.

2. The piezoelectric element according to claim 1 , wherein the piezoelectric film comprises a principal component comprising the perovskite metal oxide expressed by general formula (1):
Ba(Ti 1-x Zr x )O 3   (1),

provided that 0.02≤x≤0.13.

3. The piezoelectric element according to claim 1 , wherein an average (T E1 +T E2 )/2 of a maximum film thickness T E1 nm and a minimum film thickness T E2 nm of the first electrode and the second electrode is in a range of 0.002×T P ≤(T E1 +T E2 )/2≤500 nm.

4. The piezoelectric element according to claim 1 , further comprising an adhesion component comprising a metal of Group 4 elements and/or Group 5 elements, and existing between the substrate and one of the first electrode and the second electrode that is formed on a surface of the piezoelectric film on a substrate side.

5. The piezoelectric element according to claim 1 , wherein the piezoelectric film has an aggregate structure comprising a grain having a columnar structure.

6. The piezoelectric element according to claim 1 , wherein the piezoelectric film has residual stress therein in a direction in parallel with a surface of the substrate.

7. The piezoelectric element according to claim 1 , wherein a Curie temperature of the piezoelectric film is 121° C. or higher.

8. The piezoelectric element according to claim 1 , wherein a crystal forming a perovskite structure of the piezoelectric film is selectively oriented in a direction perpendicular to a surface of the substrate.

9. A piezoelectric actuator, comprising:
the piezoelectric element of claim 1 ; and
a vibration unit in which the piezoelectric element is formed.

10. A shake correction mechanism, comprising two or more piezoelectric actuators, each being the piezoelectric actuator of claim 9 ,
wherein the two or more piezoelectric actuators are arranged such that, when a voltage is applied thereto, the two or more piezoelectric actuators expand and contract in two or more directions.

11. An optical device, comprising:
the shake correction mechanism of claim 10 ; and
an optical member held by the shake correction mechanism.

12. An image pickup apparatus, comprising:
the shake correction mechanism of claim 10 ; and
an image pickup element unit held by the shake correction mechanism.

13. A variable shape optical element, comprising:
the piezoelectric actuator of claim 9 ;
an optical member dynamically connected to the piezoelectric actuator; and
a mechanism for changing a shape of the optical member through deformation of the piezoelectric actuator.

14. An optical device, comprising the variable shape optical element of claim 13 .

15. An optical switch, comprising the variable shape optical element of claim 13 .

16. A movable optical member, comprising:
the piezoelectric actuator of claim 9 ;
an optical member dynamically connected to the piezoelectric actuator; and
a mechanism for moving and/or rotating the optical member through deformation of the piezoelectric actuator.

17. An optical device, comprising the movable optical member of claim 16 .

18. An optical switch, comprising the movable optical member of claim 16 .

19. A micromirror device, comprising:
a plurality of micromirrors; and
a plurality of piezoelectric actuators dynamically connected to the plurality of micromirrors, respectively,
wherein each of the plurality of piezoelectric actuators is the piezoelectric actuator of claim 9 .

20. An ultrasonic wave probe, comprising the piezoelectric actuator of claim 9 and configured to oscillate an ultrasonic wave and to receive a reflected wave.

21. An ultrasonograph, comprising:
the ultrasonic wave probe of claim 20 ;
a signal processing unit; and
an image generating unit.

22. A sound component, comprising the piezoelectric actuator of claim 9 and configured to perform one of sending and receiving sound through driving of the piezoelectric actuator.

23. A liquid ejection head, comprising:
a liquid chamber comprising a vibration unit comprising the piezoelectric element of claim 1 ; and
an ejection orifice communicating with the liquid chamber.

24. A liquid ejection apparatus, comprising:
a placing unit for a transfer target; and
the liquid ejection head of claim 23 .

25. An angular velocity sensor, comprising the piezoelectric element of claim 1 and configured to convert change in shape of the piezoelectric element into angular velocity information.

26. A vibration power generator, comprising the piezoelectric element of claim 1 and configured to convert vibrational energy into electric energy.

27. The piezoelectric element according to claim 1 , wherein T P nm is 500 nm to 5,000 nm.

28. The piezoelectric element according to claim 1 , wherein T P nm is 700 nm to 4,000.

29. The piezoelectric element according to claim 1 , wherein T P nm is 1,000 nm to 3,500 nm.

30. A piezoelectric element, comprising:
a substrate;
a piezoelectric film; and
a plurality of comb electrodes,
wherein the piezoelectric film comprises a perovskite metal oxide comprising barium zirconate titanate, manganese, and trivalent bismuth,
wherein the trivalent bismuth comprises trivalent bismuth positioned at an A site of the perovskite metal oxide,
wherein the piezoelectric film satisfies 0.02≤x≤0.13,
where x is a mole ratio of zirconium to a sum of zirconium and titanium,
wherein a manganese content is 0.002 moles to 0.015 moles for 1 mole of barium zirconate titanate, and
wherein a bismuth content is 0.00042 moles to 0.00850 moles for 1 mole of barium zirconate titanate.

31. The piezoelectric element according to claim 30 , wherein the piezoelectric film comprises a principal component comprising the perovskite metal oxide expressed by general formula (1):
Ba(Ti 1-x Zr x )O 3   (1),

provided that 0.02≤x≤0.13.

32. A surface acoustic wave generator, comprising the piezoelectric element of claim 30 .

33. A piezoelectric shutter, comprising:
the surface acoustic wave generator of claim 32 ; and
a light-shielding component,
wherein the piezoelectric shutter is configured to move the light-shielding component through driving of the surface acoustic wave generator.

34. An electronic apparatus, comprising:
an electronic component; and
a piezoelectric element,
wherein the piezoelectric element comprises:
a substrate;
a first electrode;
a

Assignees

• Canon Kk

Inventors

• Matsuda Takanori
• Kubota Makoto
• Miura Kaoru

Classifications

• H02N2/186

  Vibration harvesters · CPC title

• H04N23/685

  performed by mechanical compensation · CPC title

• G01C19/5663

  Manufacturing; Trimming; Mounting; Housings · CPC title

• G01C19/5783

  Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719 · CPC title

• H04R31/00

  Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor {(manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182)} · CPC title