JPH11274589A - Lamination type piezoelectric actuator and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamination type piezoelectric actuator which can prevent breakage of a circumferential end part of a piezoelectric plate, and its manufacturing method. SOLUTION: In the lamination type piezoelectric actuator which is provided with a lamination body, wherein a plurality of electrode boards 17 consisting of a metallic thin plate 14 and a connection projection 16 and a plurality of piezoelectric plates 11 are laminated alternately and a metallic thin plate 14 is jointed to each piezoelectric plate 11 through a conductive adhesion layer 12, the connecting projection 16 is projected to at least two directions alternately from a lamination body, and the connecting projection 16 projected to the same direction is electrically connected mutually. Furthermore, an packaging resin layer 33 is formed in an outer circumferential surface of the lamination body 15, an insulating glass layer 31 is formed in both surface of the connecting projection 16 between the piezoelectric plates 11, and insulating resin 32 is filled between the insulating glass layer 31 and the piezoelectric plate 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated piezoelectric actuator and a method of manufacturing the same, for example, a precision positioning device such as an optical device, a drive element for preventing vibration, a drive element for fuel injection of an automobile engine and the like. And a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, a multilayer piezoelectric actuator which can be driven at a high voltage has been developed in order to obtain a large displacement with the multilayer piezoelectric actuator. Avoiding discharge and breakdown is one of the major development issues.

A laminated piezoelectric actuator is formed by alternately laminating a piezoelectric plate and a metal thin plate, and has a full-electrode type and a partial electrode type according to the area of a conductive adhesive layer located between the piezoelectric plate and the metal thin plate. It is classified into an electrode type. In the full-surface electrode type, the electrodes are easily attached to the side surfaces of the piezoelectric plate, and the risk of destruction accompanying creeping discharge increases. In order to suppress this danger, there has been proposed a method of manufacturing a laminated piezoelectric actuator in which electrode thin plates having a conductive paste printed on the front and back surfaces are alternately laminated with a piezoelectric plate, and pressure-baked at 400 to 700 ° C. (See JP-A-6-120583).

However, the entire electrode type is structurally more danger of creeping discharge than the partial electrode type. When a high voltage is applied, the partial electrode type is more advantageous. For the purpose of preventing the occurrence of such creeping discharge, a laminated piezoelectric actuator having a conductive adhesive layer and a thin metal plate that does not reach the outer peripheral end of the piezoelectric plate has been proposed as a partial electrode type (see Japanese Utility Model Laid-Open No. 5-38928). ).

[0005] Laminated piezoelectric actuators are classified into a contact type and an adhesive type according to the state of contact and adhesion between a piezoelectric plate and a thin metal plate. In a contact-type laminated piezoelectric actuator, a plurality of piezoelectric plates and thin metal plates are simply laminated alternately without having an adhesive action, and the laminated state is maintained by housing in a casing. Due to the relative movement of the metal sheets, the metal sheets face each other directly, and the risk of discharge between the two metal sheets increases.

On the other hand, for example, Japanese Patent Publication No. 7-4061
In the adhesive-type laminated piezoelectric actuator described in Japanese Patent Publication No. 3 (1993), since a piezoelectric plate and a thin metal plate are bonded and integrated via a conductive paste, it is easy to maintain the laminated state, and mechanical vibration such as vibration and shock is large. Even when a force is applied, relative positional deviation between the piezoelectric plate and the metal thin plate does not occur, which is an excellent effect on the problem of electric discharge between the metal thin plates.

[0007] Therefore, in terms of surface discharge, Japanese Patent Publication No.
As in the multilayer piezoelectric actuator described in Japanese Patent No. 40613, a partial electrode type and adhesive multilayer piezoelectric actuator is advantageous.

[0008]

However, in the case of the partial electrode type laminated piezoelectric actuator disclosed in Japanese Patent Publication No. 7-40613, the portion of the piezoelectric plate that is in contact with the conductive adhesive layer is greatly displaced in accordance with an electric signal. . Therefore, there is a problem that stress is easily concentrated near a boundary between a portion of the piezoelectric plate that is in contact with the conductive adhesive layer and a portion that is not in contact with the conductive adhesive layer, and cracks are easily formed, and destruction is easily caused by some cause. .

[0009] In particular, when the connection protrusion formed on the thin metal plate comes into contact with the peripheral end of the piezoelectric plate on which the conductive adhesive layer is not formed, irregular distortion occurs at the contact portion of the connection protrusion. There is a problem that it easily occurs and becomes a starting point of destruction. That is, considering that the thickness of the conductive adhesive layer of the laminated piezoelectric actuator is usually 10 μm or less,
It has been difficult to protrude from the piezoelectric plate to the outside without the connecting projection of the metal thin plate completely contacting the peripheral end of the piezoelectric plate.

In order to prevent a discharge from being generated in the laminated piezoelectric actuator due to moisture in a driving atmosphere, an exterior resin layer is formed on the outer peripheral surface of the laminated body (for example, an external resin layer is formed). In this case, the insulating resin is also filled between the connection protrusions and the piezoelectric plate. In this case, however, the connection protrusions are not filled. It has been difficult to protrude from the piezoelectric plate to the outside without touching the peripheral end of the piezoelectric plate.

That is, in general, in a laminated piezoelectric actuator of the type in which a thin metal plate is joined to a piezoelectric body, a connecting projection formed on the thin metal plate is bent along the outer peripheral surface of the laminate, and the connection protrusion is formed for each polarity. After joining the connection protrusions with solder or the like, an exterior resin layer is formed on the outer peripheral surface of the laminate. When the connection protrusions are bent along the outer peripheral surface of the laminate, for example, FIG.
As shown in FIG. 1, a part of the connection projection 2 between the piezoelectric bodies 1 is bent and easily contacts the peripheral end of the piezoelectric plate 1. For example, the conductive adhesive layer 3 opposes the contact portion with the piezoelectric plate 1 interposed therebetween. There is a problem in that an electric field is generated between them and a displacement occurs, or a mechanical stress is applied, so that a contact portion of the connection projection 2 easily becomes a starting point of destruction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laminated piezoelectric actuator capable of preventing a peripheral end of a piezoelectric plate from being damaged and a method of manufacturing the same.

[0013]

According to the present invention, there is provided a laminated piezoelectric actuator comprising: a plurality of electrode plates each comprising a metal thin plate and a connecting projection; and a plurality of piezoelectric plates alternately stacked, and the thin metal plate is electrically conductively bonded. A laminate is provided that is joined to each of the piezoelectric plates via a layer, and the connection protrusions are alternately projected from the laminate in at least two directions, and the connection protrusions that project in the same direction are electrically connected to each other. Connected to each other, further comprising an exterior resin layer formed on an outer peripheral surface of the laminated body, wherein the insulating glass layers are formed on both surfaces of connection projections between the piezoelectric plates, An insulating resin is filled between the conductive glass layer and the piezoelectric plate.

In the method of manufacturing a laminated piezoelectric actuator according to the present invention, a conductive adhesive layer may be provided on both sides of a thin metal plate, and an insulating glass thinner than the conductive adhesive layer may be provided at the root of the connection protrusion. Producing an electrode plate on which a layer is formed, the metal thin plate is located at the center of the piezoelectric plate, the root of the connection projection is located between the piezoelectric plates, and the connection projection is The electrode plates and the piezoelectric plates are alternately laminated so as to alternately project from at least two directions, and a heat treatment is performed to produce a laminated body. Then, the connection projections projecting in the same direction are electrically connected to each other. And then forming an exterior resin layer by coating the outer peripheral surface of the laminate with an insulating resin, and filling the gap between the insulating glass layer and the piezoelectric plate with the insulating resin. .

[0015]

In the laminated piezoelectric actuator of the present invention, since the insulating glass layers are formed on both surfaces of the connection projection between the piezoelectric plates, the contact between the connection projection and the piezoelectric body is made by this insulating glass layer. This prevents the piezoelectric body from being damaged due to contact between the connection projection and the peripheral end of the piezoelectric plate even in the case of a partial electrode type or an adhesive type laminated piezoelectric actuator.

In addition, since the space between the insulating glass layer and the piezoelectric plate is filled with an insulating resin having a low elastic modulus, such as silicon rubber, the laminated piezoelectric actuator is not deformed.
The connection projection can move to some extent freely, the displacement amount is improved, and breakage is prevented. That is, in the laminated piezoelectric actuator, when an electric field is applied, displacement in the laminating direction and displacement in the radial direction of the piezoelectric plate occur, but an insulating glass having a high elastic modulus is formed between the connection projection and the piezoelectric plate. Is not completely filled (joined), and the insulating resin is interposed, so that the insulating resin does not hinder the radial displacement of the piezoelectric plate in the laminating direction and does not impede the periphery of the piezoelectric plate. Stress concentration at the end is suppressed, and breakage of the piezoelectric plate is prevented.

Further, an electrode plate in which an electrically conductive adhesive layer is formed on both sides of a thin metal plate and an insulating glass layer thinner than the thickness of the electrically conductive adhesive layer at the root of the connection projection is formed in advance, is prepared. Are located at the center of the piezoelectric plate, the base of the connection projection is located between the piezoelectric plates, and the connection projections alternately protrude from the piezoelectric plate in at least two directions. After alternately laminating and heat-treating to produce a laminate, the connecting projections projecting in the same direction are electrically connected to each other, and then, by forming an exterior resin layer on the outer peripheral surface of the laminate, An insulating glass layer is formed on both surfaces of the connection protrusion between the piezoelectric plates, and a laminated piezoelectric actuator in which an insulating resin is filled between the insulating glass layer and the piezoelectric plate can be easily obtained.

[0018]

FIG. 1 shows a laminated piezoelectric actuator according to the present invention, and FIG. 2 is an enlarged sectional view showing a part of FIG. Note that the exterior resin layer is omitted in FIG. 1 and 2, reference numeral 11 denotes a piezoelectric body. These piezoelectric plates 11 are made of Pb (Zr, Ti) O ₃
(Hereinafter, abbreviated as PZT).

The piezoelectric material constituting the piezoelectric plate 11 is, for example, a piezoelectric ceramic material containing lead zirconate titanate as a main component, but is not limited thereto. Any may be used. As the piezoelectric material constituting the piezoelectric plate 11, as the piezoelectric strain constant d ₃₃ is high is preferable.

In particular, Pb, Zr, Ti,
A composite perovskite compound containing Zn and Sb, and the composition formula based on the molar ratio of these metal elements is represented by Pb
_{1-xy Sr x Ba y (} Zn 1/3 Sb 2/3) a (Ni 1/2
Te _1/2 ) _b Zr _c Ti _{1 -abc} O ₃ ,
When the molar ratio of x, y, a, b, and c is 0 ≦ x ≦ 0.12, 0
≦ y ≦ 0.12, 0 <x + y, 0.05 ≦ a ≦ 0.1
2, with respect to 100 parts by weight of the basic component satisfying 0 ≦ b ≦ 0.015 and 0.43 ≦ c ≦ 0.52, PbO and Nb ₂ O ₅ having an equimolar ratio in a total amount of 0.2 to A piezoelectric ceramic composition containing 1.2 parts by weight is desirable. The thickness t of the piezoelectric plate 11 is desirably 0.2 to 0.6 mm from the viewpoint of miniaturization and application of a high voltage.

A plurality of piezoelectric plates 11 are stacked, two conductive adhesive layers 12 are formed therebetween, and a disc-shaped thin metal plate 14 is interposed between the conductive adhesive layers 12. And a laminate 15 is formed. Metal sheet 14
3, a connection projection 16 is formed as shown in FIG.
An electrode plate 17 is formed, and the connection protrusion 16 is
As shown in (1), the piezoelectric plate 11 protrudes in the radial direction.

Further, the metal thin plates 14 are interposed between the piezoelectric plates 11 so that the connection projections 16 are alternately turned 180 degrees. These metal thin plates 14 are connected to the positive electrode depending on the positions of the connection projections 16. Metal sheet for negative electrode and metal sheet for negative electrode. The tip of the connection projection 16 is the laminate 1
5 is bent along the outer peripheral surface, and its tip is joined to the connection projection 16 projecting in the same direction by soldering or the like.

The electrode plate 17 has conductivity, and is preferably, for example, a metal such as silver, brass, copper, or stainless steel. The thickness of the metal sheet 14 is preferably as thin as possible so as not to contribute to the displacement amount, for example, 20 to 50 μm. The metal sheet 14 is preferably smaller than the piezoelectric plate 11 so as not to be exposed on the outer peripheral surface of the laminated body 15 in order to prevent a short circuit or discharge with another metal sheet 14.

The conductive adhesive layer 12 is preferably made of a metal powder such as Ag and a glass component and melted at about 400 ° C. This is because, when heated under pressure during lamination, the glass component contained in the conductive adhesive is melted, the piezoelectric plates 11 are firmly joined to each other, and peeling at the interface caused by repeated application of a high electric field is prevented. Can be a laminate 1
This is because the reliability of No. 5 can be improved. The conductive adhesive is
In particular, 70 to 98% by weight of Ag powder and PbO-SiO
It is preferably made of a 2-30 wt% glass component consisting of ₂ -B ₂ O _3.

In the multilayer piezoelectric actuator of the present invention, as shown in FIG. 2, the insulating glass layers 31 are formed on both surfaces of the connection projections 16 between the piezoelectric plates 11,
An insulating resin 32 is filled between the insulating glass layer 31 and the piezoelectric plate 11. The insulating resin 32 is filled when the outer peripheral surface of the laminate 15 is coated with the insulating resin to form the exterior resin layer 33.

Reference numeral 35 denotes an inert body disposed on the upper and lower surfaces of the laminated body 15 for transmitting piezoelectrically inert mechanical energy.

In the laminated piezoelectric actuator constructed as described above, first, as shown in FIG. 4, a conductive adhesive layer 12 is provided on both sides of a thin metal plate 14, and a conductive adhesive layer is provided on the base of the connection projection 16. The electrode plate 17 on which the insulating glass layer 31 is formed thinner than the thickness of the layer 12 is manufactured.

That is, first, an insulating glass paste is applied to a position corresponding to the root of the connection projection 16 of the electrode plate 17, dried, and heat-treated at 500 to 600 ° C. to form the insulating glass layer 31. Thereafter, a conductive adhesive is applied to both sides of the position corresponding to the metal thin plate 14, dried, and punched into a shape as shown in FIG.

The conductive adhesive layer 12 formed on the thin metal plate 14 has a surface roughness Ra of 0.2 after coating and drying.
It is desirable that it is not more than μm.

The insulating glass layer 31 formed at the base of the connection projection 16 is made of, for example, PbO--SiO ₂ --B ₂ O ₃
An insulating glass paste made of, for example, a glass component PbO—SiO ₂ — having the same composition as the conductive adhesive layer 12 is used.
B ₂ O ₃ is desirable.

Next, the electrode plates 17 and the piezoelectric plates 11 are alternately stacked so that the metal thin plate 14 is located at the center of the piezoelectric plate 11. At this time, the root of the connection projection 16 is
The connection layers 16 are stacked so that the connection projections 16 alternately project from the piezoelectric plate 11 in at least two directions.

At the upper and lower ends, an inert body 35 is disposed.
With light pressure applied to prevent displacement, 4
A pressure bonding is performed at 00 to 500 ° C. for 1 to 3 hours, and a laminate 15 in which the piezoelectric body 11 and the metal thin plate 14 are bonded by the conductive adhesive layer 12 is produced. In this state, the connection protrusion 16
A gap is formed between the base of the piezoelectric element 11 and the piezoelectric plate 11.

The distal ends of the connection projections 16 protruding from the piezoelectric plate 11 are bent in the axial direction of the laminated body 15, respectively.
The bent tip is electrically connected to the adjacent connection projection 16 by spot welding or soldering.

Thereafter, the connection projections 1 electrically connected are formed.
Attach a lead wire to the end of 6, and apply a DC voltage of 0.5 to 2 KV in silicon oil for 10 to 30 minutes to polarize.

Lastly, in order to prevent discharge due to moisture or the like in the driving atmosphere, the outer peripheral surface of the laminated body 15 is covered with an insulating resin to form an exterior resin layer 33, and the space between the piezoelectric plates 11 The insulating glass layer 31 between the outer peripheral surface of the base and the connection projection 16 and at the root of the connection projection 16
The gap between the piezoelectric actuator and the piezoelectric plate 11 is filled with the insulating resin 32 so that there is no gap, thereby producing the multilayer piezoelectric actuator of the present invention.

In the multilayer piezoelectric actuator of the present invention,
Since the insulating glass layers 31 are formed on both surfaces of the connection projections 16 between the piezoelectric plates 11, the insulation glass layers 31 prevent the connection projections 16 from contacting with the piezoelectric body 11, thereby ensuring insulation. The connection protrusion 16 and the piezoelectric plate 11
The piezoelectric body 11 can be prevented from being damaged by contact with the peripheral end of the piezoelectric body 11.

Between the insulating glass layer 31 and the piezoelectric plate 11, an insulating resin 32 having a small elastic modulus such as silicon rubber is provided.
, The connection projection 16 can move to some extent freely in response to the deformation of the laminated piezoelectric actuator, and the displacement can be improved and breakage can be prevented.

Further, in the laminated piezoelectric actuator of the present invention, the conductive adhesive layers 12 are
An electrode plate 17 having an insulating glass layer 31 thinner than the thickness of the conductive adhesive layer 12 formed at the root of the connection projection 16 is manufactured. The metal thin plate 14 is located at the center of the piezoelectric plate 11 and connected. The electrode plate 17 and the piezoelectric plate 1 are arranged such that the base of the connection projection 16 is located between the piezoelectric plates 11 and the connection projections 16 alternately protrude from the piezoelectric plate 11 in at least two directions.
1 are alternately laminated, so that the insulating resin layer 33 is formed in the gap between the insulating glass layer 31 at the base of the connection projection 16 and the piezoelectric plate 11 during the laminating step. Resin 32 can be filled.

In the case where the conductive paste is printed only on the portion of the surface of the piezoelectric body to which the metal sheet is to be bonded as in the conventional case, the surface of the end portion of the applied conductive adhesive layer rises, and when the layers are laminated. Although it was difficult to fill the gaps generated between the metal sheet 14 and the conductive adhesive layer 12, in the present invention, punching into a predetermined shape after forming the conductive adhesive layer 12 and the insulating glass layer 31 was performed. Thus, the electrode plate 17 is formed, so that the swelling of the end of the conductive adhesive layer 12 is reduced, and an actuator having no void at the adhesive interface can be easily obtained.

[0040]

[Example] _{Pb 1-xy Sr x Ba y} (Zn 1/3 S
_{b 2/3) a (Ni 1/2 Te} 1/2) b Zr c Ti 1-abc
When expressed as O ₃ , x = 0.04, y = 0.02, a =
Pb having an equimolar ratio with respect to 100 parts by weight of the basic component satisfying 0.075, b = 0.005, and c = 0.47.
Both surfaces of a PZT sintered body containing 0.5 parts by weight of O and Nb ₂ O ₅ added in total were polished to obtain a disk-shaped piezoelectric plate 11 having a diameter of 20 mm and a thickness of 0.5 mm.

First, an insulating glass paste made of PbO—SiO ₂ —B ₂ O ₃ as an insulating glass layer 31 was applied to a 25-μm-thick Ag thin plate so as to have a thickness of 5 μm, dried and heat-treated at 500 to 600 ° C. After that, a conductive paste is printed and dried as the conductive adhesive layer 12 so that the thickness becomes 10 μm and the surface roughness Ra becomes 0.2 μm or less.
An electrode plate 17 composed of a connection protrusion 16 of 2 mm × 3 mm and a circular thin metal plate 14 having a diameter of 19 mm as shown in FIG.
Punched into the shape. Conductive adhesive, was used an Ag powder 97 wt%, the ratio of the glass 3% by weight consisting primarily of _{PbO-SiO 2 -B 2 O 3} .

As the inert body 35, PZT was baked in a disk shape, and both sides were polished so as to have a diameter of 20 mm and a thickness of 5 mm.

In order to sandwich the piezoelectric plate 11 between the metal thin plates 14, 100 piezoelectric plates 11 and 101 metal thin plates 14
Are polymerized and laminated, and inert bodies 35 are arranged at both ends thereof. After applying slight pressure so as not to cause displacement, about 3
A weight of kg was put on the plate, and pressure bonding was performed at 450 ° C. for 1 hour.

Incidentally, the connecting projections 16 of the metal thin plates 14 were alternately arranged so as to be at the same position every other layer.

The distal ends of the connecting projections 16 projecting in the radial direction of the piezoelectric plate 11 are each bent in the axial direction, and the bent distal ends are spot-welded to the adjacent connecting projections 16.
The lead wire for the positive electrode and the lead wire for the negative electrode were connected.

This was placed in silicone oil at 80 ° C. for 1.5
Polarization was performed by applying a DC voltage of KV for 30 minutes.

Thereafter, silicone rubber is used as an insulating resin, and this rubber is applied to the outer peripheral surface of the laminated body 15, and is further removed by vacuum defoaming between the connecting projection 16 and the outer peripheral surface of the piezoelectric plate 11, and the insulating glass. The space between the layer 31 and the piezoelectric plate 11 was filled so that air did not enter, and dried and cured at 120 ° C. for 1 hour to produce a laminated piezoelectric actuator of the present invention as shown in FIGS. 1 and 2.

In the obtained laminated piezoelectric actuator, 50
As a result of applying a DC voltage of 0 V, a displacement amount of 40 μm was obtained. Also, 50 V is applied to the laminated piezoelectric actuator.
When the voltage was increased at / sec, the voltage was 2300 V and the peripheral end of the piezoelectric plate 11 was damaged.

On the other hand, with the laminated piezoelectric actuator of FIG. 1, a conventional laminated piezoelectric actuator in which an insulating glass layer was not formed at the base of the connection projection was manufactured, and a DC voltage of 500 V was applied thereto. As a result, 40μ
An amount of displacement of m was obtained. Also, as described above, 50 V /
When the pressure was increased in sec, the peripheral edge of the piezoelectric plate 11 was damaged at 1000 V.

From the above results, in the laminated piezoelectric actuator of the present invention, the root of the connection projection 16 and the piezoelectric body 1
It can be seen that sufficient insulation between the piezoelectric actuator and the conventional piezoelectric actuator can be achieved, and the piezoelectric actuator can be driven with a voltage twice or more that of the conventional multilayer piezoelectric actuator.

The displacement of the laminated piezoelectric actuator was measured by a laser displacement meter with the sample fixed on a vibration isolating table.

[0052]

As described in detail above, in the laminated piezoelectric actuator of the present invention, the insulating glass layers are formed on both surfaces of the connecting projections between the piezoelectric plates. Contact between the projection and the piezoelectric body is prevented, insulation can be secured, and even in the case of a partial electrode type or adhesive type laminated piezoelectric actuator, the piezoelectric body is in contact with the connection projection and the peripheral end of the piezoelectric plate. Damage can be prevented. In addition, the space between the insulating glass layer and the piezoelectric plate is filled with an insulating resin having a low elastic modulus, such as silicon rubber, so that the connection projection can move freely with respect to the deformation of the laminated piezoelectric actuator. In addition, the displacement can be improved and breakage can be prevented.

Then, an electrode plate was prepared in which a conductive adhesive layer was formed on both sides of a thin metal plate and an insulating glass layer thinner than the conductive adhesive layer was formed at the base of the connection projection. By alternately laminating the plates and the piezoelectric plates, the laminated piezoelectric actuator of the present invention can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a side view of a laminated piezoelectric actuator of the present invention.

FIG. 2 is an enlarged sectional view showing a part of FIG. 1;

FIG. 3 is a plan view of an electrode plate.

FIG. 4 shows an electrode plate in which an insulating glass layer is formed at the base of a connection projection and a conductive adhesive layer is formed on the surface of a thin metal plate, (a) is a plan view, and (b) is a side view. is there.

FIG. 5 is a cross-sectional view showing a conventional laminated piezoelectric actuator in which a root of a connection projection is in contact with a piezoelectric plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Piezoelectric plate 12 ... Conductive adhesive layer 14 ... Metal thin plate 15 ... Laminated body 16 ... Connection protrusion 17 ... Electrode plate 31 ... Insulating glass layer 32 ...・ Insulating resin layer 33 ・ ・ ・ Outer resin layer

Continued on the front page (72) Inventor Takeshi Setoguchi 1-4, Yamashita-cho, Kokubu-shi, Kagoshima Inside Kyocera Research Institute (72) Inventor Koki Ashida 1-4-4 Yamashita-cho, Kokubu-shi, Kagoshima Kyocera Corporation In the laboratory

Claims (2)

[Claims] 1. A laminate in which a plurality of electrode plates each comprising a metal thin plate and a connecting projection and a plurality of piezoelectric plates are alternately stacked, and the thin metal plate is joined to each of the piezoelectric plates via a conductive adhesive layer. And the connection projections are alternately projected from the laminate in at least two directions, the connection projections projecting in the same direction are electrically connected to each other, and an outer surface is provided on an outer peripheral surface of the laminate. A laminated piezoelectric actuator formed by forming a resin layer, wherein an insulating glass layer is formed on both surfaces of a connection projection between the piezoelectric plates, and an insulating resin is provided between the insulating glass layer and the piezoelectric plate. A laminated piezoelectric actuator characterized by being filled. 2. An electrode plate having an electrically conductive adhesive layer formed on both sides of a thin metal plate and an insulating glass layer formed at the base of a connecting projection at a thickness smaller than the thickness of the electrically conductive adhesive layer is produced. Is located at the center of the piezoelectric plate, the root of the connection protrusion is located between the piezoelectric plates, and the connection protrusions alternately project from the piezoelectric plate in at least two directions, After alternately laminating the electrode plate and the piezoelectric plate and performing a heat treatment to produce a laminate, the connection protrusions protruding in the same direction are electrically connected to each other, and then insulated on the outer peripheral surface of the laminate. A method for manufacturing a laminated piezoelectric actuator, comprising: forming an exterior resin layer by coating a conductive resin; and filling a gap between the insulating glass layer and the piezoelectric plate with an insulating resin.