Piezoelectric element, and piezoelectric vibrating apparatus, portable terminal, sound generator, sound generating apparatus, and electronic device comprising the piezoelectric element

Patent metadata

Field	Value
Publication number	US-2016337760-A1
Application number	US-201415112270-A
Country	US
Kind code	A1
Filing date	Jun 27, 2014
Priority date	Jan 30, 2014
Publication date	Nov 17, 2016
Grant date	—

Abstract

A piezoelectric element includes: a stacked body in which internal electrodes and piezoelectric layers are laminated; surface electrodes disposed at least on one principal face of the stacked body; and side electrodes disposed on a side face of the stacked body, the internal electrodes extending to the side face, the side electrodes electrically connecting the internal electrodes extending to the side face and the surface electrodes. The internal electrodes each includes a first primary electrode having an active region and a led-out region extending to the side face of the stacked body, the internal electrodes each including a first secondary electrode, the first primary electrodes being disposed in inter-piezoelectric layer regions, the first secondary electrodes being disposed in the inter-piezoelectric layer regions so as to be apart from the led-out regions of the first primary electrodes, and the first secondary electrode is connected to one of the side electrodes.

First claim

1 . A piezoelectric element, comprising:
a stacked body in which a plurality of internal electrodes and a plurality of piezoelectric layers are laminated; a plurality of surface electrodes disposed at least on one principal face of the stacked body; and a plurality of side electrodes disposed on a side face of the stacked body, the plurality of internal electrodes extending to the side face, the plurality of side electrodes electrically connecting the plurality of internal electrodes extending to the side face and the plurality of surface electrodes, the plurality of internal electrodes each including a first primary electrode having an active region and a led-out region extending to the side face of the stacked body, the plurality of internal electrodes each including a first secondary electrode, the first primary electrodes being disposed in inter-piezoelectric layer regions, the first secondary electrodes being disposed in the inter-piezoelectric layer regions so as to be apart from the led-out regions of the first primary electrodes, and the first secondary electrode being connected to one of the plurality of side electrodes.

2 . The piezoelectric element according to claim 1 ,
wherein the first primary electrode and the first secondary electrode disposed both in an inter-piezoelectric layer region are connected to different side electrodes.

3 . The piezoelectric element according to claim 1 ,
wherein the stacked body is shaped in a rectangular plate as seen in a plan view, an arrangement of a first primary electrode and a first secondary electrode which are located on one principal face side in the stacking direction of the stacked body and an arrangement of a first primary electrode and a first secondary electrode which are located on the other principal face side in the stacking direction of the stacked body are in line-symmetric relation to each other about a widthwise central axis, and the first primary electrode located on the one principal face side and the first secondary electrode located on the other principal face side are connected to one of the side electrodes, and the first primary electrode located on the other principal face side and the first secondary electrode located on the one principal face side are connected to the other one of the side electrodes.

4 . The piezoelectric element according to claim 1 ,
wherein the first primary electrode and the first secondary electrode disposed both in an inter-piezoelectric layer region both extend to a side face.

5 . The piezoelectric element according to claim 4 ,
wherein the stacked body is shaped in a rectangular plate as seen in a plan view, and the first primary electrode and the first secondary electrode are extended to an end face.

6 . The piezoelectric element according to claim 5 ,
wherein the led-out region of the first primary electrode and the first secondary electrode are equal in width.

7 . The piezoelectric element according to claim 1 ,
wherein the stacked body includes second primary electrodes which are disposed alternately with the first primary electrodes in the stacking direction so as to face the active regions of the first primary electrodes, and the stacked body includes a region where the first secondary electrodes and the second primary electrodes are opposed to each other as seen in a transparent plan view in the stacking direction of the stacked body.

8 . The piezoelectric element according to claim 1 ,
wherein the stacked body includes second primary electrodes which are disposed alternately with the first primary electrodes in the stacking direction so as to face the active regions of the first primary electrodes, the second primary electrodes each have an active region and a led-out region extending to the side face of the stacked body, and the plurality of internal electrodes each include a second secondary electrode disposed in an inter-piezoelectric layer region in which the second primary electrode is located so as to be apart from the led-out region of the second primary electrode, and the second secondary electrode is connected to one of the plurality of side electrodes.

9 . The piezoelectric element according to claim 8 ,
wherein the stacked body includes a region where the second secondary electrode and the first primary electrode are opposed to each other as seen in a transparent plan view in the stacking direction of the stacked body.

10 . The piezoelectric element according to claim 2 ,
wherein materials of the first primary electrode, the second primary electrode, and the first secondary electrode, are same in composition.

11 . The piezoelectric element according to claim 8 ,
wherein materials of the first primary electrode, the second primary electrode, the first secondary electrode, and the second secondary electrode, are same in composition.

12 . The piezoelectric element according to claim 1 ,
wherein the piezoelectric element is built as a bimorph piezoelectric element.

13 . A piezoelectric vibrating apparatus, comprising:
the piezoelectric element according to claim 1 ; and a vibration plate joined to the other principal face of the piezoelectric element.

14 . A portable terminal, comprising:
the piezoelectric element according to claim 1 ; an electronic circuit; a display; and a housing, the display or the housing being joined to the other principal face of the piezoelectric element.

15 . A sound generator, comprising:
the piezoelectric element according to claim 1 ; a vibration plate to which the piezoelectric element is attached, the vibration plate vibrating in response to vibration of the piezoelectric element; and a support body attached to at least part of an outer periphery of the vibration plate, the support body supporting the vibration plate.

16 . A sound-generating apparatus, comprising:
the sound generator according to claim 15 ; and a housing which accommodates the sound generator.

17 . An electronic device, comprising:
the sound generator according to claim 15 ; an electronic circuit connected to the sound generator; and a housing which accommodates the electronic circuit and the sound generator, the electronic device having a function of causing the sound generator to produce sound.

Assignees

• Kyocera Corp

Inventors

• Suenaga Hiroshi

Classifications

• H04R2499/15

  Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops · CPC title

• H04R17/005 Primary

  using a piezoelectric polymer · CPC title

• H04R1/026

  Supports for loudspeaker casings · CPC title

• H04R2499/11

  Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's · CPC title

• H04R17/00 Primary

  Piezoelectric transducers; Electrostrictive transducers (piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners {H10N30/00}) · CPC title