JP4725432B2 - Multilayer piezoelectric element and piezoelectric device - Google Patents

Description

  The present invention relates to a multilayer piezoelectric element and a piezoelectric device including the multilayer piezoelectric element.

As a piezoelectric device, a device including a base made of metal and a laminated piezoelectric element fixed to the base is known (for example, see Patent Document 1).
JP 2002-299713 A

  Patent Document 1 discloses a multilayer piezoelectric element having the following configuration. The multilayer piezoelectric element described in Patent Document 1 includes a multilayer body in which a plurality of piezoelectric layers and a plurality of internal electrodes are stacked, and first and second layers that are electrically insulated from each other on the multilayer body. And an external electrode. The stacked body includes first and second main surfaces facing each other in the stacking direction of the plurality of piezoelectric layers, and a first extending in the stacking direction so as to connect the first and second main surfaces and facing each other. And a second end face. The first external electrode has an electrode portion disposed on the first main surface, an electrode portion disposed on the first end surface, and an electrode portion disposed on the second main surface. The second external electrode has an electrode portion arranged on the first main surface, an electrode portion arranged on the second end surface, and an electrode portion arranged on the second main surface.

  The plurality of internal electrodes include a plurality of first internal electrodes connected to the first external electrode at a first end surface, and a plurality of second internal electrodes connected to the second external electrode at a second end surface. An electrode. The first internal electrodes and the second internal electrodes are alternately arranged along the stacking direction so as to face each other with the piezoelectric layer interposed therebetween.

  In the piezoelectric device described in Patent Document 1, the laminated piezoelectric element is fixed to the base via an adhesive so that the main surface on which the first external electrode and the second external electrode are arranged faces the base. Has been. However, in the piezoelectric device described in Patent Document 1, there is a possibility that the first external electrode and the second external electrode are short-circuited through the substrate due to poor adhesion, adhesion of conductive foreign matter, or the like. When the first external electrode and the second external electrode are short-circuited, the stacked piezoelectric element is not driven.

  It is an object of the present invention to provide a multilayer piezoelectric element and a piezoelectric device that can suppress the occurrence of a short circuit between external electrodes.

  The multilayer piezoelectric element according to the present invention includes a plurality of piezoelectric layers and a plurality of internal electrodes, and first and second main surfaces facing each other in the stacking direction of the plurality of piezoelectric layers, A laminated body having first and second end faces extending in the laminating direction and facing each other so as to connect between the first and second main faces, and disposed over the first main face and the first end face. The first external electrode, the second external electrode disposed on the second end surface, and the external conductor disposed on the second main surface, the first external electrode and the second external electrode And the external conductor are electrically insulated from each other on the multilayer body, and the plurality of internal electrodes includes a plurality of first internal electrodes connected to the first external electrode at the first end face, A plurality of second internal electrodes connected to the second external electrode at the two end faces, And the second internal electrode are opposed to each other with the piezoelectric layer interposed therebetween, and the first main electrode in the first external electrode has the second internal electrode sandwiching the piezoelectric layer constituting the first main surface. The electrode portions arranged on the first main surface of the first external electrode in the piezoelectric layer and the second are alternately arranged along the stacking direction so as to face the electrode portions arranged on the surface. A region sandwiched between the first internal electrode and the second internal electrode, a region sandwiched between the first internal electrode and the second internal electrode, and an external conductor; The region sandwiched between the two is polarized.

  In the multilayer piezoelectric element according to the present invention, in the piezoelectric layer, a region sandwiched between the electrode portion disposed on the first main surface of the first external electrode and the second internal electrode, the first internal electrode, A region sandwiched between the second internal electrodes and a region sandwiched between one of the first internal electrode and the second internal electrode and the external conductor are polarized. Therefore, when a voltage is applied between the first external electrode and the second external electrode, a voltage is also applied between the first internal electrode and the second internal electrode, and the first external electrode An electric field is generated in a region sandwiched between the electrode portion disposed on the first main surface and the second internal electrode and a region sandwiched between the first internal electrode and the second internal electrode. The region is displaced as an active part. At this time, since no voltage is applied to the external conductor, the internal electrodes adjacent to the second main surface among the plurality of internal electrodes (one of the first internal electrode and the second internal electrode) An electric field is not generated in a region sandwiched between the internal electrode) and the external conductor, and the region is not displaced as an active portion.

  Thus, the external conductor is electrically insulated from the first and second external electrodes, and no voltage is applied. Therefore, even when the multilayer piezoelectric element of the present invention is fixed so that the second main surface on which the external conductor is disposed is opposed to the base made of metal, the first external electrode and the second external electrode Is very unlikely to short circuit through the substrate.

  By the way, when the material constituting the piezoelectric layer (for example, a piezoelectric ceramic material such as lead zirconate titanate (PZT), barium titanate, or lead titanate) is polarized, the polarization axis direction (c-axis direction) Therefore, the piezoelectric layer is displaced in the polarized state with respect to the state before polarization. For this reason, if there is a non-polarized piezoelectric layer in the laminate, stress is generated at the interface with the polarized and displaced piezoelectric layer. This stress may cause cracks and the like. However, in the present invention, in the piezoelectric layer, the region sandwiched between the electrode portion disposed on the first main surface of the first external electrode and the second internal electrode, the first internal electrode and the second internal electrode Since the region sandwiched between the electrodes and the region sandwiched between one of the first internal electrode and the second internal electrode and the external conductor are polarized, each piezoelectric element is in a state after polarization. Generation of stress at the interface of the body layer can be suppressed.

  Preferably, the first external electrode, the second external electrode, and the external conductor include a metal material. In this case, when the multilayer piezoelectric element of the present invention is fixed so that the second main surface faces the base made of metal, the metal between the external conductor and the base is bonded to each other. And the substrate can be easily joined. For joining the outer conductor and the substrate, soldering, bonding with an adhesive, or the like is possible. In addition, since the conductors (the first external electrode and the external conductor) containing the metal material are disposed on the first main surface and the second main surface that face each other, when forming the first external electrode and the external conductor The stress acting on the laminate is balanced, and deformation of the laminate can be suppressed.

  The piezoelectric device according to the present invention includes the multilayer piezoelectric element and a metal base, and the multilayer piezoelectric element is fixed to the base so that the second main surface faces the base. It is characterized by that.

  Since the piezoelectric device according to the present invention includes the multilayer piezoelectric element described above, the multilayer piezoelectric element is fixed in such a manner that the second main surface on which the outer conductor is arranged is opposed to the base made of metal. In addition, it is very unlikely that the first external electrode and the second external electrode are short-circuited through the base.

  ADVANTAGE OF THE INVENTION According to this invention, the lamination type piezoelectric element and piezoelectric device which can suppress generation | occurrence | production of the short circuit between external electrodes can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  First, the configuration of the multilayer piezoelectric element PE according to this embodiment will be described with reference to FIGS. 1 and 2 are schematic perspective views illustrating the multilayer piezoelectric element according to the present embodiment. FIG. 3 is a schematic diagram for explaining a cross-sectional configuration of the multilayer piezoelectric element according to the present embodiment.

  The multilayer piezoelectric element PE includes a multilayer body 1 having a polygonal column shape (in this embodiment, a quadrangular column shape), a first external electrode 11, a second external electrode 13, and an external conductor 15. I have. The multilayer piezoelectric element PE has a length in the X-axis direction of 1.2 mm, a length (width) in the Y-axis direction of 0.3 mm, and a length (height) in the Z-axis direction of 0.15 mm. It is.

  The laminated body 1 includes a rectangular first main surface 2 and a second main surface 3 facing each other, a first end surface 4 and a second end surface 5 facing each other, and a first side surface 6 facing each other. And a second side surface 7. The first and second end faces 4 and 5 extend in the short side direction of the first and second main faces 2 and 3 so as to connect the first and second main faces 2 and 3. The first and second side surfaces 6 and 7 extend in the long side direction of the first and second main surfaces 2 and 3 so as to connect the first and second main surfaces 2 and 3.

  The first external electrode 11 is disposed so as to extend over the first main surface 2 and the first end surface 4. The second external electrode 13 is disposed on the second end face 5. The outer conductor 15 is disposed on the second main surface 3. The first external electrode 11, the second external electrode 13, and the external conductor 15 are electrically insulated from each other on the outer surface of the multilayer body 1. In the present embodiment, the second external electrode 13 is disposed so as to extend over the first main surface 2 and the second end surface 5. In order to ensure electrical insulation on the second main surface 3, it is preferable not to arrange the first external electrode 11 and the second external electrode 13 on the second main surface 3. As will be described later, the first external electrode 11, the second external electrode 13, and the external conductor 15 are made of Au, and are formed on the corresponding surfaces of the multilayer body 1 by sputtering. The first external electrode 11, the second external electrode 13, and the external conductor 15 only need to contain a metal material as a main component. For example, Ag, Cu, Sn, or Ni is used in addition to Au. be able to. In this embodiment, the thickness of the 1st external electrode 11, the 2nd external electrode 13, and the external conductor 15 is 1-2 micrometers.

  As shown in FIG. 3, the multilayer body 1 includes a plurality of piezoelectric layers 21 and a plurality of internal electrodes 31. The piezoelectric layer 21 and the internal electrode 31 extend in a direction parallel to the first and second main surfaces 2 and 3, and are stacked in a direction opposite to the first and second main surfaces 2 and 3. In the multilayer body 1, the first main surface 2 and the second main surface 3 face each other in the stacking direction of the piezoelectric layers 21.

  Each piezoelectric layer 21 is made of, for example, a piezoelectric ceramic material mainly composed of lead zirconate titanate, and is formed in a rectangular thin plate shape. In an actual laminated piezoelectric element PE, each piezoelectric layer 21 is integrated so that the boundary between the piezoelectric layers 21 is not visible. In the present embodiment, the thickness of each piezoelectric layer 21 is 10 to 50 μm.

  The plurality of internal electrodes 31 include a plurality of first internal electrodes 33 and a plurality of second internal electrodes 35. One end of each first internal electrode 33 is drawn out to the first end face 4, and is physically and electrically connected to the first external electrode 11 at the first end face 4. One end of each second internal electrode 35 is drawn out to the second end surface 5, and is physically and electrically connected to the second external electrode 13 at the second end surface 5. Each internal electrode 33, 35 is made of, for example, a conductive material mainly composed of silver and palladium. In the present embodiment, the thickness of each internal electrode 33, 35 is 0.5-3 μm.

  The first internal electrodes 33 and the second internal electrodes 35 are alternately arranged along the stacking direction of the piezoelectric layers 21 so as to face each other with the piezoelectric layers 21 in between. Of the plurality of internal electrodes 31, the second internal electrode 35 is located closest to the first main surface 2 when viewed in the stacking direction. That is, among the plurality of internal electrodes 31, the second internal electrode 35 is positioned adjacent to the first main surface 2. Thus, the second internal electrode 35 is disposed on the first main surface 2 of the first external electrode 11 with the piezoelectric layer 21 constituting the first main surface 2 interposed therebetween in the multilayer body 1. It will be located so as to face the electrode portion.

  Of the plurality of internal electrodes 31, the first internal electrode 33 is located closest to the second main surface 3 when viewed in the stacking direction. That is, among the plurality of internal electrodes 31, the first internal electrodes 33 are positioned adjacent to each other so as to face the second main surface 3. As a result, the first internal electrode 33 is positioned in the multilayer body 1 so as to face the external conductor 15 with the piezoelectric layer 21 constituting the second main surface 3 interposed therebetween. The second internal electrodes 35 may be positioned adjacent to each other so as to face the second main surface 3.

  In the multilayer body 1, the second internal electrode 35 adjacent to the electrode portion disposed on the first main surface 2 of the first external electrode 11 in the piezoelectric layer 21 so as to face the first main surface 2. The region sandwiched between the first internal electrode 33 and the second internal electrode 35 and the region sandwiched between the first internal electrode 33 and the external conductor 15 are polarized. When the second internal electrodes 35 are adjacent to each other so as to face the second main surface 3, the region sandwiched between the second internal electrodes 35 and the external conductor 15 is polarized.

  Subsequently, a manufacturing procedure of the multilayer piezoelectric element PE described above will be described.

First, a base paste is prepared by mixing an organic binder, an organic solvent, or the like with a piezoelectric ceramic material containing PZT as a main component. And the green sheet used as the piezoelectric material layer 21 is shape | molded using this base paste. Moreover, an organic binder, an organic solvent, etc. are mixed with the metal material (for example, silver: palladium = 7: 3) which consists of silver and palladium of a predetermined ratio, and the electroconductive paste for electrode pattern formation is produced. Instead of Ag and Pd, gold (Au), platinum (Pt), or an alloy thereof may be used.

  Next, an electrode pattern corresponding to the first internal electrode 33 is formed on the green sheet. Further, an electrode pattern corresponding to the second internal electrode 35 is formed on another green sheet. Each electrode pattern is formed by screen printing the above-described conductive paste.

  Next, a green sheet on which an electrode pattern corresponding to the first internal electrode 33 is formed and a green sheet on which an electrode pattern corresponding to the second internal electrode 35 is formed are alternately stacked. A green sheet in which no is formed is laminated on the outermost layer to produce a green laminate.

  Next, while heating the green laminate at a predetermined temperature (for example, about 60 ° C.), it is pressed in the stacking direction at a predetermined pressure (for example, about 100 MPa).

  Next, the green laminate is degreased (that is, debindered) at a predetermined temperature (for example, about 400 ° C.) and then fired at a predetermined temperature (for example, about 1100 ° C.) for a predetermined time (for example, about 2 hours). To do.

  Next, the fired sintered body is cut into a predetermined size. The sintered body is cut by, for example, a diamond blade.

  Next, electrode portions corresponding to the first external electrode 11, the second external electrode 13, and the external conductor 15 are formed on the outer surface of the cut sintered body by a sputtering method. At this time, as shown in FIG. 4, an electrode portion E2 corresponding to the second external electrode 13 and an electrode portion E3 corresponding to the external conductor 15 are integrally formed. The electrode portion E1 corresponding to the first external electrode 11 is electrically insulated from the electrode portion E2 corresponding to the second external electrode 13 and the electrode portion E3 corresponding to the external conductor 15 on the sintered body SB. ing. Each electrode portion may be formed by baking a conductive paste mainly composed of a metal material, or may be formed by electrolytic plating.

  Next, a polarization process is performed on the sintered body SB in which electrode portions corresponding to the first external electrode 11, the second external electrode 13, and the external conductor 15 are formed. Here, the first external is set so that the electric field strength becomes a predetermined value (for example, 2 to 3 kV / mm) at a predetermined temperature (for example, about 120 ° C.) for a predetermined time (for example, about 2 minutes). A voltage is applied between the electrode portion E1 corresponding to the electrode 11 and the electrode portions E2 and E3 corresponding to the integrally formed second external electrode 13 and external conductor 15.

  Next, the sintered body SB subjected to the polarization treatment is cut into a predetermined size. The sintered body is cut by, for example, a diamond blade. At this time, the electrode portion E2 corresponding to the second external electrode 13 and the electrode portion E3 corresponding to the external conductor 15 are separated. Specifically, the electrode part E2 corresponding to the integrally formed second external electrode 13 and the intermediate part of the electrode part E3 corresponding to the external conductor 15 are cut to be separated. Thereby, the multilayer piezoelectric element PE is obtained.

  In the obtained multilayer piezoelectric element PE, the electrode portion disposed on the first main surface 2 of the first external electrode 11 and the first main surface 2 are opposed to each other in the piezoelectric layer 21 by the polarization treatment described above. Thus, the region sandwiched between the second internal electrodes 35 adjacent to each other, the region sandwiched between the first internal electrode 33 and the second internal electrode 35, and the first internal electrode 33 and the external conductor 15 The sandwiched area will be polarized.

  In the multilayer piezoelectric element PE, when a voltage is applied between the first external electrode 11 and the second external electrode 13, a voltage is also applied between the first internal electrode 33 and the second internal electrode 35. Is done. In the piezoelectric layer 21, the region sandwiched between the electrode portion disposed on the first main surface 2 of the first external electrode 11 and the second internal electrode 35, and the first internal electrode 33 and the first internal electrode 35 An electric field is generated in a region sandwiched between the two internal electrodes 35, and each region is displaced as an active portion. At this time, since no voltage is applied to the outer conductor 15, the region between the first inner electrode 33 and the outer conductor 15 that are adjacent to each other so as to face the second main surface 3 in the piezoelectric layer 21 is not present. An electric field is not generated, and the region is not displaced as an active portion.

  In the manufacturing procedure described above, the electrode portion E2 corresponding to the second external electrode 13 and the electrode portion E3 corresponding to the external conductor 15 are separated after the polarization processing, but the present invention is not limited to this. After separating the electrode part E2 corresponding to the second external electrode 13 and the electrode part E3 corresponding to the external conductor 15, that is, after forming the second external electrode 13 and the external conductor 15, the second external electrode A connection conductor that electrically connects the electrode 13 and the external conductor 15 may be formed to perform polarization treatment, and the connection conductor may be removed after the polarization treatment.

  When the second inner electrode 35 is adjacent to the second main surface 3, the electrode portion E1 corresponding to the first outer electrode 11 and the electrode portion E3 corresponding to the outer conductor 15 are provided. The polarization process is performed in an electrically connected state.

  Next, an actuator (piezoelectric device) AC including the above-described stacked piezoelectric element PE will be described with reference to FIGS. 5 and 6. Here, an example in which the present invention is applied to a slider unit of a hard disk device will be described. FIG. 5 is a perspective view showing the slider unit according to the present embodiment. FIG. 6 is an exploded perspective view of the actuator according to the present embodiment.

  The slider SL has a substantially rectangular parallelepiped shape, and has a width of about 1.0 mm, a length of about 1.235 mm, and a height of about 0.3 mm. Inside the slider SL, a thin film magnetic head H is disposed so as to be exposed to an air bearing surface (ABS) facing the hard disk.

  The position of the slider SL is controlled by a two-stage servo control system, and the position is also controlled by the actuator AC in addition to the voice coil motor. The actuator AC is a device that can control the position of the slider SL more finely than the voice coil motor. The actuator AC relatively displaces the slider SL with respect to the load beam 43 of the suspension 41. That is, the suspension 41 is rotated by the voice coil motor when the slider SL is moved relatively large, and the actuator AC is driven when the slider SL is slightly moved.

  The actuator AC is composed of a frame 51 as a base and a pair of laminated piezoelectric elements PE.

  The frame 51 has a base portion 53 and a pair of curved portions 55 and 57. The frame 51 is configured by pressing a metal plate such as stainless steel, and the base 53 and the pair of curved portions 55 and 57 are integrally formed. Base 53 includes a first portion 53a joined to gimbal 45 and a second portion 53b on which slider SL is mounted. The pair of curved portions 55 and 57 are connected to the end portions of the first and second portions 53 a and 53 b, and extend in a direction orthogonal to the base portion 53.

  The multilayer piezoelectric element PE is fixed to the outside of the curved portions 55 and 57 so that the second main surface 3 faces the curved portions 55 and 57. The multilayer piezoelectric element PE is fixed to the curved portions 55 and 57 by soldering the outer conductor 15 and the curved portions 55 and 57.

  The first portion 53a is joined to the gimbal 45 by laser welding or adhesion. As a result, the actuator AC is mounted on the suspension 41. The slider SL is joined to the second portion 53b by bonding or the like.

  Next, driving of the actuator AC will be described.

  When a voltage is applied between the first external electrode 11 and the second external electrode 13 of the multilayer piezoelectric element PE, the multilayer piezoelectric element PE is displaced according to the value of the voltage. When a voltage is applied to one stacked piezoelectric element PE so as to be shortened and a voltage is applied to the other stacked piezoelectric element PE so as to be extended, the pair of curved portions 55 and 57 has the same first Curve in the direction of In addition, when a voltage is applied to one stacked piezoelectric element PE so as to extend and a voltage is applied to the other stacked piezoelectric element PE so as to shorten, the pair of curved portions 55 and 57 is changed to the first. Curved in a second direction opposite to the first direction. As a result, the slider SL mounted on the second portion 53b slightly moves in the first direction or the second direction.

  As described above, according to the present embodiment, in the multilayer piezoelectric element PE, the external conductor 15 is electrically insulated from the first and second external electrodes 11 and 13 and voltage is applied. There is no. Therefore, even when the multilayer piezoelectric element PE is fixed so that the second main surface 3 on which the external conductor 15 is disposed is opposed to the curved portions 55 and 57, the first external electrode 11 and the second external electrode 11 The wrinkle that the electrode 13 is short-circuited through the curved portions 55 and 57 is extremely low.

  In the present embodiment, in the piezoelectric layer 21, a region sandwiched between the electrode portion disposed on the first main surface 2 of the first external electrode 11 and the second internal electrode 35, the first internal electrode 33, Since the region sandwiched between the second internal electrodes 35 and the region sandwiched between the first internal electrode 33 and the external conductor 15 are polarized, at the interface between the piezoelectric layers 21 in the state after polarization. Generation of stress can be suppressed. As a result, the occurrence of cracks in the laminate 1 can be suppressed.

  In the present embodiment, when the laminated piezoelectric element PE is fixed so that the second main surface 2 faces the curved portions 55 and 57, the metal-to-metal bonding between the outer conductor 15 and the curved portions 55 and 57 is performed. Therefore, the laminated piezoelectric element PE and the curved portions 55 and 57 can be easily joined. In addition to the soldering described above, the outer conductor 15 and the curved portions 55 and 57 can be bonded by an adhesive (for example, an epoxy, silicone, acrylic, or the like). In addition to the soldering described above, adhesion with an adhesive (for example, an epoxy, silicone, acrylic, or the like) is possible. When the outer conductor 15 and the curved portions 55 and 57 are joined by bonding, the range of selection of the adhesive to be used can be expanded.

  In the multilayer piezoelectric element PE, the conductors (the first external electrode 11 and the external conductor 15) made of metal are disposed on the first main surface 2 and the second main surface 3 that are opposed to each other. The stress acting on the multilayer body 1 when the electrode 11 and the external conductor 15 are formed is balanced, and deformation of the multilayer body 1 can be suppressed.

  The preferred embodiments of the present invention have been described above. However, the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

  For example, the shape of the laminated body 1, the number of laminated layers of the piezoelectric layer 21 and the internal electrodes 33 and 35 are not limited to those illustrated.

  In the present embodiment, the present invention is applied to the actuator AC for driving the slider SL on which the thin film magnetic head H is formed. However, the present invention can be applied not only to the actuator AC but also to driving various driven bodies. .

It is a schematic perspective view which shows the lamination type piezoelectric element which concerns on this embodiment. It is a schematic perspective view which shows the lamination type piezoelectric element which concerns on this embodiment. It is a schematic diagram for demonstrating the cross-sectional structure of the laminated piezoelectric element which concerns on this embodiment. It is a schematic diagram for demonstrating the preparation procedure of the laminated piezoelectric element which concerns on this embodiment. It is a perspective view which shows the slider unit which concerns on this embodiment. It is a disassembled perspective view of the actuator which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laminated body, 2 ... 1st main surface, 3 ... 2nd main surface, 4 ... 1st end surface, 5 ... 2nd end surface, 11 ... 1st external electrode, 13 ... 2nd external electrode 15 ... external conductor, 21 ... piezoelectric layer, 31 ... internal electrode, 33 ... first internal electrode, 35 ... second internal electrode, 51 ... frame, 53 ... base, 55,57 ... curved part, AC ... Actuator, PE: Multilayer piezoelectric element.

Claims (2)

A laminated piezoelectric element fixed to a base made of metal,
A plurality of piezoelectric layers and a plurality of internal electrodes are stacked, and the first and second main surfaces facing each other in the stacking direction of the plurality of piezoelectric layers, and between the first and second main surfaces A laminated body having first and second end faces extending in the laminating direction so as to connect each other and facing each other;
A first external electrode disposed over the first major surface and the first end surface and including a metallic material ;
A second external electrode disposed on the second end face and containing a metallic material ;
An outer conductor disposed on the second main surface and containing a metallic material ,
The first external electrode, the second external electrode, and the external conductor are electrically insulated from each other on the laminate.
The plurality of internal electrodes include a plurality of first internal electrodes connected to the first external electrode at the first end surface and a plurality of internal electrodes connected to the second external electrode at the second end surface. A second internal electrode;
The first internal electrode and the second internal electrode face each other across the piezoelectric layer, and the second internal electrode sandwiches the piezoelectric layer constituting the first main surface. And alternately arranged along the laminating direction so as to face electrode portions arranged on the first main surface of the first external electrode,
A region of the piezoelectric layer sandwiched between the electrode portion disposed on the first main surface of the first external electrode and the second internal electrode, the first internal electrode and the second internal electrode; A region sandwiched between internal electrodes and a region sandwiched between any one of the first internal electrode and the second internal electrode and the external conductor are polarized ,
The outer conductor is the second main surface which is located a substrate and a surface facing made of metal, laminated piezoelectric element wherein an external conductor, characterized in Rukoto is joined to the base body. The laminated piezoelectric element according to claim 1 and a base made of a metal,
The multilayer piezoelectric element is fixed to the base body so that the second main surface faces the base body by bonding the outer conductor to the base body .

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