Piezoelectric/electrostrictive device and method of manufacturing same

• US 6,605,887 B2
• Filed: 09/18/2002
• Issued: 08/12/2003
• Est. Priority Date: 10/01/1999
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Kumura, Koji, Takeuchi, Yukihisa, Ikeda, Koji, Nanataki, Tsutomu, Shibata, Kazuyoshi
• Primary Examiner(s): Zarroli, Michael C.
• Application Number:
  US10/246,032
• Publication Number:
  US 20030020369A1
• Time in Patent Office: 328 Days
• Field of Search: 310/321, 310/328, 360/109
• US Class Current: 310/321
• CPC Class Codes: H10N 30/053 by integrally sintering piezoelectric or electrostrictive bodies and electrodes
• CPC Class Codes: H10N 30/2042 Cantilevers, i.e. having one fixed end
• CPC Class Codes: H10N 30/2043 connected at their free ends, e.g. parallelogram type
• CPC Class Codes: H10N 30/302 Sensors
• CPC Class Codes: H10N 30/501 having a non-rectangular cross-section in a plane parallel to the stacking direction, e.g. polygonal or trapezoidal in side view

Abstract

A piezoelectric/electrostrictive device including a pair of mutually opposing thin plate sections and a fixation section for supporting the thin plate sections. A piezoelectric/electrostrictive element is arranged on each of the pair of thin plate sections. Movable sections, having mutually opposing end surfaces, are formed proximate the ends of the thin plate sections. A distance between the end surfaces is not less than a length of the movable sections.

Claims

1. A piezoelectric/electrostrictive device comprising:

a pair of mutually-opposing thin plate sections and a fixation section for supporting said thin plate sections;

movable sections provided at first end portions of said pair of thin plate sections; and

one or more piezoelectric/electrostrictive elements arranged on at least one thin plate section of said pair of thin plate sections, each of said piezoelectric/electrostrictive elements including at least one electrode containing two portions separated from one another by a slit.

2. The piezoelectric/electrostrictive device according to claim 1, wherein any one of said movable sections and said fixation section has a cutoff section, and a part of said cutoff section defines mutually-opposing end surfaces of said any one of said movable sections and said fixation section.

3. The piezoelectric/electrostrictive device according to claim 1, wherein said thin plate sections, said movable sections, and said fixation section are composed of a ceramic substrate integrated into one unit by co-firing a ceramic green laminate and cutting off unnecessary portions.

4. The piezoelectric/electrostrictive device according to claim 3, wherein said piezoelectric/electrostrictive element has a film-shaped configuration, and is integrated with said ceramic substrate by means of sintering.

5. The piezoelectric/electrostrictive device according to claim 2, wherein a gap is formed between said mutually-opposing end surfaces.

6. The piezoelectric/electrostrictive device according to claim 2, wherein a member which has substantially the same composition as a constitutive member of any one of said movable sections and said fixation section, or a plurality of members which are compositionally different therefrom are interposed between said mutually-opposing end surfaces, and an area of a surface of said member opposed to said end surface is substantially the same as an area of said end surface.

7. The piezoelectric/electrostrictive device according to claim 6, wherein at least one member of said plurality of members is organic resin.

8. The piezoelectric/electrostrictive device according to claim 6, wherein a hole, which is formed by both inner walls of said pair of thin plate sections, inner walls of said movable sections, inner walls of said plurality of members, and an inner wall of said fixation section, is filled with a gel material.

9. The piezoelectric/electrostrictive device according to claim 2, wherein said device has such a structure that internal residual stress, which has been generated in at least one of said thin plate sections and said piezoelectric/electrostrictive element during production, is released by forming said mutually opposing end surfaces.

10. The piezoelectric/electrostrictive device according to claim 1, wherein said piezoelectric/electrostrictive element comprises a piezoelectric/electrostrictive layer, said at least one electrode, and another electrode, both of which are formed on said piezoelectric/electrostrictive layer.

11. The piezoelectric/electrostrictive device according to claim 10, wherein said piezoelectric/electrostrictive element is constructed in a stacked form comprising a plurality of units each including said piezoelectric/electrostrictive layer, said at least one electrode, and said another electrode.

12. The piezoelectric/electrostrictive device according to claim 1, wherein said pair of mutually-opposing thin plate sections extend along a first direction and said slit extends along a second direction substantially perpendicular to said first direction.