JP2001315100A - Piezoelectric/electrostrictive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric/electrostrictive device capable of being formed into a small size, unlikely to be influenced by detrimental vibrations, capable of making quick response, having a high mechanical strength, and excellent in the handling easiness, shock resistance, and moistureproofness. SOLUTION: A pair of thin plate parts 12a and 12b confronting each other and a stationary part 14 to support the thin plate parts 12a and 12b are formed into a single piece by ceramics, and an object 18 is attached between the forefront parts of the thin plate parts 12a and 12b, and piezoelectric/electrostrictive elements 20a and 20b are installed on the side faces of the thin plate parts 12a and 12b, wherein the area of those surfaces of the object 18 opposing to the thin plate parts 12a and 12b is set greater than the area of those surfaces 34a and 34b of the thin plate parts 12a and 12b where the object is to be mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a piezoelectric / electrostrictive device having a movable portion that operates based on a displacement operation of a piezoelectric / electrostrictive element.

[0002]

2. Description of the Related Art In recent years, in the fields of optics, magnetic recording, precision processing, etc., displacement elements capable of adjusting the optical path length and position on the order of submicrons have been required, and piezoelectric / electrostrictive materials (for example, ferroelectric materials) have been required. Development of a displacement element utilizing displacement caused by an inverse piezoelectric effect or an electrostrictive effect caused when a voltage is applied to a body or the like has been promoted.

Conventionally, as such a displacement element, for example, as shown in FIG. 7, a plate-like body 2 made of a piezoelectric / electrostrictive material is used.
A piezoelectric actuator is disclosed in which a fixed portion 204, a movable portion 206, and a beam portion 208 for supporting the fixed portion 204 and the movable portion 206 are integrally formed by providing a hole portion 202 in the beam portion 00 and an electrode layer 210 is further provided in the beam portion 208. (For example, see
No. 136665).

In the piezoelectric actuator, when a voltage is applied to the electrode layer 210, the beam 208 expands and contracts in the direction connecting the fixed part 204 and the movable part 206 due to the inverse piezoelectric effect and the electrostriction effect. Can be displaced arcuately or rotationally in the plane of the plate 200.

On the other hand, Japanese Patent Application Laid-Open No. 63-64640 discloses an actuator using a bimorph, in which electrodes of the bimorph are provided in a divided manner, and the divided electrodes are selected and driven to thereby achieve high-precision positioning. This publication (especially, FIG. 4) discloses a structure in which, for example, two bimorphs are used facing each other.

[0006]

However, in the above-described piezoelectric actuator, the displacement of the piezoelectric / electrostrictive material in the expansion / contraction direction (that is, the in-plane direction of the plate-like body 200) is transmitted to the movable portion 206 as it is. There is a problem that the operation amount of the movable part 206 is small.

Further, since all parts of the piezoelectric actuator are made of a piezoelectric / electrostrictive material, which is a fragile and relatively heavy material, the mechanical strength is low, and the handleability, impact resistance, and moisture resistance are poor. In addition, there is a problem in that the piezoelectric actuator itself is heavy and susceptible to harmful vibrations (for example, residual vibration and noise vibration during high-speed operation) in operation.

[0008] In order to solve the above problems, the hole 202
It has been proposed to fill the material with a flexible filler, but it is obvious that simply using the filler reduces the amount of displacement due to the inverse piezoelectric effect or the electrostrictive effect.

The present invention has been made in view of such problems, and can reduce the size of a device, and is less susceptible to harmful vibration, can respond at high speed, and has a high mechanical strength. It is an object of the present invention to provide a piezoelectric / electrostrictive device which is high in handling property, impact resistance and moisture resistance.

[0010]

According to the present invention, a pair of opposed thin plate portions and a fixing portion for supporting these thin plate portions are integrally formed of ceramics, and an object is provided between the tip portions of the pair of thin plate portions. Is attached, at least one of the pair of thin plate portions is provided with at least one piezoelectric / electrostrictive element, and an area of a surface of the object facing the thin plate portion is an object in the thin plate portion. It is characterized in that it is larger than the area of the mounting surface.

Thus, since the object is attached in a form sandwiched between the pair of thin plate portions, the increase in size due to the attachment of the object can be effectively suppressed. In addition, since the pair of thin plate parts and the fixed part are formed integrally with ceramics, they are less susceptible to harmful vibrations, are capable of high-speed response, have high mechanical strength, handleability, and shock resistance. And excellent in moisture resistance.

The piezoelectric / electrostrictive element is formed in a film shape,
You may make it integrate with the said thin plate part by baking. Further, the object may be fixed to an object mounting surface of the thin plate portion via an adhesive. In this case, the adhesive may be an organic resin, or may be glass, brazing material, or solder.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a piezoelectric / electrostrictive device according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a piezoelectric / electrostrictive device 10 according to this embodiment has a pair of thin plate portions 1 opposed to each other.
2a and 12b, and a fixed portion 14 supporting the thin plate portions 12a and 12b, a ceramic base 16 integrally formed of ceramics, and a pair of thin plate portions 12a and 12b.
b, and an object 18 interposed between the distal ends of b.
Piezoelectric / electrostrictive elements 20a and 20b are provided on outer surfaces (hereinafter referred to as side surfaces) of the pair of thin plate portions 12a and 12b, respectively.
Is arranged and configured. In the piezoelectric / electrostrictive device 10, an object is displaced by driving the piezoelectric / electrostrictive elements 20a and / or 20b.

In such an integrated ceramic material, since the adhesive does not intervene in the joints of the respective parts, there is almost no change in the state over time, so that the reliability of the joints is high and it is advantageous for securing rigidity. In addition to having a simple structure, it can be easily manufactured by a ceramic green sheet laminating method described later.

The piezoelectric / electrostrictive elements 20a and 20b
Prepares piezoelectric / electrostrictive elements 20a and 20b as separate bodies and attaches them to the ceramic base 16 with an adhesive such as an organic resin or glass, brazing, soldering, eutectic bonding, etc. By using the method, it is formed directly on the side surfaces of the thin plate portions 12a and 12b instead of the attachment.

Each of the piezoelectric / electrostrictive elements 20a and 20b has a piezoelectric / electrostrictive layer 22 and a pair of electrodes 24 and 26 formed on both sides of the piezoelectric / electrostrictive layer 22, respectively. One of the electrodes 24 and 26 is formed on at least a pair of thin plate portions 12a and 12b.

In the present embodiment, the piezoelectric / electrostrictive layer 22 and the pair of electrodes 24 and 26 each have a multilayer structure, and one electrode 24 and the other electrode 26 are alternately formed so as to have a substantially comb-shaped cross section. One of these electrodes 2
4 and the other electrode 26 overlapped with the piezoelectric / electrostrictive layer 22 interposed therebetween to form piezoelectric / electrostrictive elements 20a and 20b having a multi-stage configuration.

In FIG. 1, the piezoelectric / electrostrictive layer 22 has a three-layer structure, and one of the electrodes 24 is located on the lower surface of the first layer (side surfaces of the thin plate portions 12a and 12b) and the upper surface of the second layer. An example is shown in which the electrode 26 is formed in a comb shape and the other electrode 26 is formed in a comb shape so as to be located on the upper surface of the first layer and the upper surface of the third layer.
In the case of this configuration, one electrode 24 and the other electrode 26 are connected to each other and shared, so that the terminal 28
Since the number of the piezoelectric / electrostrictive elements 20a and 20b can be reduced, the number of piezoelectric / electrostrictive elements 20a and 20b can be prevented from increasing.

Each of the pair of thin plate portions 12a and 12b has an inwardly thicker tip portion, and the opposing surfaces 34a and 34b of each of the thicker portions 32a and 32b serve as an object for attaching the object 18. Functions as a mounting surface.

On the other hand, the object 18 has such a size as to fit between the thick portions 32a and 32b of the pair of thin plate portions 12a and 12b, and has a substantially rectangular parallelepiped shape (of course, is limited to a rectangular parallelepiped). Is not something). The area of the side surface of the object 18 (the surface facing the thick portions 32a and 32b of the thin plate portions 12a and 12b) is equal to the thin plate portions 12a and 12b.
b is set larger than the area of the object mounting surfaces 34a and 34b. In FIG. 1, the object 18 has a front end surface substantially coincident with a front end surface of each of the thin plate portions 12a and 12b, and a rear end surface (a surface facing the fixing portion 14) of the thin plate portions 12a and 12b.
Are in a positional relationship protruding toward the fixing portion 14 from the thick portions 32a and 32b. And the object 18 is
It is fixed to the object mounting surfaces 34a and 34b of the thin plate portions 12a and 12b via an adhesive 36.

In the piezoelectric / electrostrictive device 10 according to the above-described embodiment, as shown in FIG. 4, for example, the distances La and Lb from the central axis n of the object 18 to the object mounting surfaces 34a and 34b are set. It is preferable to make them substantially equal.

The application of a voltage to the pair of electrodes 24 and 26 is performed by fixing the fixed portion 1 of the electrodes 24 and 26, respectively.
4 through terminals (pads) 28 and 30 formed on both side surfaces (element formation surfaces).
The position of each of the terminals 28 and 30 is such that the terminal 28 corresponding to one electrode 24 is formed near the rear end of the fixed part 14, and the terminal 30 corresponding to the other electrode 26 on the external space side is fixed to the fixed part 14.
It is formed near the inner wall.

In this case, the piezoelectric / electrostrictive device 10 can be fixed separately using a surface different from the surface on which the terminals 28 and 30 are arranged. 10 and the circuit and terminals 28 and 30
High reliability can be obtained for both electrical connections between them. In this configuration, the terminals 28 and 30 are electrically connected to the circuit by a flexible printed circuit (also called FPC), a flexible flat cable (also called FFC), wire bonding, or the like.

The piezoelectric / electrostrictive device 1 according to the present embodiment
As the configuration of 0, in addition to the configuration shown in FIG. 1, the size of the object 18 may be further increased like the piezoelectric / electrostrictive device 10a according to the first modified example shown in FIG. In the example of FIG. 2, a case is shown in which the size of the side surface of the object 18 is larger in the vertical and horizontal directions than the sizes of the object mounting surfaces 34a and 34b.

Further, like the piezoelectric / electrostrictive device 10b according to the second modification shown in FIG.
The thin portions 12a and 12b may have the same thickness without providing the thick portions 32a and 32b at the tip of b.
In this case, a larger object 18 can be attached.

In the present embodiment, since the piezoelectric / electrostrictive elements 20a and 20b have a multi-stage structure, the generated force of the piezoelectric / electrostrictive elements 20a and 20b increases, thereby achieving a large displacement and a piezoelectric displacement. By increasing the rigidity of the / electrostrictive device 10 itself, a higher resonance frequency is achieved, and a higher speed of the displacement operation can be easily achieved.

If the number of stages is increased, the driving force is increased, but the power consumption is also increased. Therefore, in actual implementation, the number of stages may be determined as appropriate according to the application and use state. . In the piezoelectric / electrostrictive device 10 according to this embodiment, the piezoelectric / electrostrictive elements 20a and 20b
Even if the driving force is increased by using a multi-stage structure,
Since the width (distance in the Y-axis direction) of 2a and 12b is invariable, it is a very preferable device when applied to an actuator such as positioning of a magnetic head for a hard disk used in a very narrow gap and ringing control. .

Here, the operation of the piezoelectric / electrostrictive device 10 according to this embodiment will be described. First, for example, 2
When the two piezoelectric / electrostrictive elements 20a and 20b are in a natural state, that is, when both the piezoelectric / electrostrictive elements 20a and 20b are not performing a displacement operation, as shown in FIG. The (central axis of the fixed portion) m substantially coincides with the central axis n of the object 18.

From this state, for example, as shown in the waveform diagram of FIG. 5A, a sine wave Wa having a predetermined bias potential Vb is applied to the pair of electrodes 24 and 26 of one piezoelectric / electrostrictive element 20a. As shown, the other piezoelectric /
The pair of electrodes 24 and 26 in the electrostrictive element 20b have a sine wave W having a phase substantially 180 ° different from the sine wave Wa.
Apply b.

When a maximum voltage is applied to the pair of electrodes 24 and 26 of one piezoelectric / electrostrictive element 20a, for example, the piezoelectric / electrostrictive layer of one piezoelectric / electrostrictive element 20a 22 is contracted and displaced in the direction of its main surface. As a result, for example, as shown in FIG. 6, a stress is generated in one thin plate portion 12a in a direction to bend the thin plate portion 12a rightward as shown by an arrow A. The portion 12a bends rightward. At this time, no voltage is applied to the pair of electrodes 24 and 26 of the other piezoelectric / electrostrictive element 20b. It bends rightward following the deflection of the portion 12a. As a result, the object 18 is displaced, for example, rightward with respect to the major axis m of the piezoelectric / electrostrictive device 10. Note that the displacement amount changes according to the maximum value of the voltage applied to each of the piezoelectric / electrostrictive elements 20a and 20b. For example, the displacement amount increases as the maximum value increases.

In particular, when a piezoelectric / electrostrictive material having a high coercive electric field is applied as a constituent material of the piezoelectric / electrostrictive layer 22, as shown by the double-dashed lines in FIGS. 5A and 5B, So that the level of the value is slightly negative
The bias potential may be adjusted. In this case, by driving the piezoelectric / electrostrictive element (for example, the other piezoelectric / electrostrictive element 20b) to which the negative level is applied, for example, the bending direction of the other thin plate portion 12b is the same as the bending direction of the one thin plate portion 12a. Is generated, and the displacement amount of the object 18 can be further increased. That is, by using a waveform as shown by a two-dot chain line in FIGS. 5A and 5B, the piezoelectric / electrostrictive element 20b or 20a to which a negative level is applied is used.
Is the piezoelectric / electrostrictive element 20a that is the main part of the displacement operation
Alternatively, a function of supporting 20b can be provided.

As described above, in the piezoelectric / electrostrictive device 10 according to the present embodiment, the minute displacement of the piezoelectric / electrostrictive elements 20a and 20b is changed into a large displacement operation by using the bending of the thin plate portions 12a and 12b. Since the signal is amplified and transmitted to the object 18, the object 18 can be largely displaced with respect to the major axis m of the piezoelectric / electrostrictive device 10.

In particular, in this embodiment, since the object 18 is attached in a form sandwiched between the pair of thin plate portions 12a and 12b, the size is increased by attaching the object 18, especially in the Y-axis direction. Enlargement can be effectively suppressed. Further, in the present embodiment, the pair of thin plate portions 12a and 12b and the fixing portion 14 are integrally formed of ceramics, so that they are hardly affected by harmful vibration, can perform high-speed response, and have a high mechanical response. High strength, excellent handling, impact resistance and moisture resistance.

In this embodiment, the piezoelectric /
Each of the electrostrictive elements 20 a and 20 b includes a piezoelectric / electrostrictive layer 22 and a pair of electrodes 24 and 26 formed on both sides of the piezoelectric / electrostrictive layer 22. One of the electrodes 24 is connected to at least the thin plate portions 12a and 12a.
b, the vibrations caused by the piezoelectric / electrostrictive elements 20a and 20b are applied to the thin plate portions 12a and 12b.
b, the light can be efficiently transmitted to the object 18 and the response can be improved.

In this embodiment, a portion (substantially driving portion) in which the pair of electrodes 24 and 26 overlap with the piezoelectric / electrostrictive layer 22 interposed therebetween is formed from a part of the fixing portion 14 to the thin plate portion 12a and the thin plate portion 12a. Since it is formed continuously so as to fit over a part of 12b, the disadvantage that the displacement operation of the object 18 is limited can be avoided, and the displacement amount of the object 18 can be increased.

The actual size of each part is determined by the area of the object mounting surfaces 34a and 34b of the thin plate parts 12a and 12b,
4, a bonding area for mounting other members, a bonding area for mounting electrode terminals, etc., the strength, durability, required displacement and resonance frequency of the entire piezoelectric / electrostrictive device 10, and a driving voltage, etc. In consideration of the above.

In the piezoelectric / electrostrictive device 10, the shape of the device 10 is not a conventional plate-like shape (the thickness in the direction perpendicular to the displacement direction is small),
And the fixing portion 14 have a rectangular parallelepiped shape (the thickness in the direction orthogonal to the displacement direction is large), and the object 18 and the fixing portion 14
Pair of thin plate portions 12a and 12b so that
Is provided, the rigidity of the piezoelectric / electrostrictive device 10 in the Y-axis direction can be selectively increased.

That is, in this piezoelectric / electrostrictive device 10,
Only the movement of the object 18 in the plane (in the XZ plane) can be selectively generated, and the movement of the object in the YZ plane (the movement in the so-called tilting direction) can be suppressed.

Next, each component of the piezoelectric / electrostrictive device 10 according to this embodiment will be described.

As the object 18, the piezoelectric / electrostrictive device 1
Various members are attached according to the purpose of use. For example, if the piezoelectric / electrostrictive device 10 is used for positioning of a magnetic head of a hard disk drive or a ringing suppressing mechanism, a member that requires positioning such as a magnetic head, a slider having a magnetic head, and a suspension having a slider is attached. Can be

As described above, the fixing portion 14 is a thin plate 1
2a and 12b, for example, when used for positioning the magnetic head of the hard disk drive, a carriage arm attached to a VCM (voice coil motor), a fixed plate or suspension attached to the carriage arm Fixed part 14 etc.
, The whole of the piezoelectric / electrostrictive device 10 is fixed. Further, as shown in FIG. 1, terminals 28 and 30 and other members for driving the piezoelectric / electrostrictive elements 20a and 20b may be arranged on the fixing portion 14.

The material forming the fixing portion 14 is not particularly limited as long as it has rigidity, but ceramics to which a ceramic green sheet laminating method described later can be applied can be suitably used. Specifically, zirconia including stabilized zirconia, partially stabilized zirconia, alumina, magnesia, silicon nitride, aluminum nitride, a material mainly containing titanium oxide, and the like, and a mixture of these as a main component Zirconia, in terms of high mechanical strength and toughness
Particularly, a material mainly containing stabilized zirconia and a material mainly containing partially stabilized zirconia are preferable.

As described above, the thin plate portions 12a and 12b are portions driven by the displacement of the piezoelectric / electrostrictive elements 20a and 20b. The thin plate portions 12a and 12b are flexible thin plate-shaped members, and are provided with piezoelectric /
It has a function of amplifying the expansion and contraction displacement of the electrostrictive elements 20 a and 20 b as a bending displacement and transmitting it to the object 18. Therefore,
The shape and material of the thin plate portions 12a and 12b are sufficient as long as they have flexibility and mechanical strength enough not to be damaged by bending deformation, and are appropriately selected in consideration of the responsiveness and operability of the object 18. can do.

As the material forming the thin plate portions 12a and 12b, the same ceramics as the fixing portion 14 can be preferably used. Zirconia, in particular, a material containing stabilized zirconia as a main component and a partially stabilized zirconia as a main component The material to be used is most preferably used because it has high mechanical strength, high toughness, and low reactivity with the piezoelectric / electrostrictive layer 22 and the electrode material even if it is thin.

The above-mentioned stabilized zirconia and partially stabilized zirconia are preferably those stabilized and partially stabilized as follows. That is, compounds that stabilize and partially stabilize zirconia include yttrium oxide, ytterbium oxide, cerium oxide, calcium oxide, and magnesium oxide. By adding and containing at least one compound among them, zirconia partially becomes Or completely stable,
The intended zirconia can be stabilized not only by adding one kind of compound but also by adding those compounds in combination.

The amount of each compound added is 1 to 30 mol%, preferably 1.5 to 10 mol% in the case of yttrium oxide or ytterbium oxide, and in the case of cerium oxide. , 6-50 mol%,
It is preferably 8 to 20% by mole, and in the case of calcium oxide or magnesium oxide, 5 to 40% by mole, and preferably 5 to 20% by mole. Among them, yttrium oxide is particularly preferred as a stabilizer. It is preferably used, and in that case, it is desirable that the content be 1.5 to 10 mol%, more preferably 2 to 4 mol%. Further, it is possible to add alumina, silica, transition metal oxide or the like as an additive such as a sintering aid in a range of 0.05 to 20 wt%, but the piezoelectric / electrostrictive elements 20 a and 20 b
In the case of employing sintering integration by a film forming method as a forming method, it is also preferable to add alumina, magnesia, transition metal oxide or the like as an additive.

In order to obtain a mechanical strength and a stable crystal phase, the average crystal grain size of zirconia is set to 0.05 to 0.05.
It is desirable that the thickness be 3 μm, preferably 0.05 to 1 μm. As described above, the thin plate portions 12a and 12b can be made of the same ceramics as the fixing portion 14, but are preferably made of substantially the same material. This is advantageous in reducing the performance, the strength of the piezoelectric / electrostrictive device 10, and the complexity of manufacturing.

Each of the piezoelectric / electrostrictive elements 20 a and 20 b has at least a piezoelectric / electrostrictive layer 22 and a pair of electrodes 24 and 26 for applying an electric field to the piezoelectric / electrostrictive layer 22. The piezoelectric / electrostrictive elements 20a and 20b of a bimorph type or the like can be used.
Since the unimorph type combined with a and 12b is more excellent in the stability of the generated displacement amount and advantageous in reducing the weight,
It is suitable for such a piezoelectric / electrostrictive device 10.

The piezoelectric / electrostrictive elements 20a and 20b are
As shown in FIG. 1, it is preferable to form the thin plate portions 12a and 12b on the side surfaces thereof since the thin plate portions 12a and 12b can be driven more.

The piezoelectric / electrostrictive layer 22 is preferably made of piezoelectric ceramics, but it is also possible to use electrostrictive ceramics, ferroelectric ceramics, or antiferroelectric ceramics. However, this piezoelectric / electrostrictive device 10
Is used for positioning of a magnetic head of a hard disk drive or the like, since the linearity between the amount of displacement of the object 18 and the drive voltage or output voltage is important, it is preferable to use a material having a small strain history and a coercive electric field of 10 kV. /
It is preferable to use a material of less than mm.

Specific materials include lead zirconate, lead titanate, lead magnesium niobate, lead nickel niobate, lead zinc niobate, lead manganese niobate, lead antimony stannate, lead manganese tungstate, and cobalt niobium. Ceramics containing lead oxide, barium titanate, sodium bismuth titanate, potassium sodium niobate, strontium bismuth tantalate, etc., alone or as a mixture are mentioned.

In particular, a material having a high electromechanical coupling coefficient and a piezoelectric constant, a small reactivity with the thin plate portions (ceramics) 12a and 12b when the piezoelectric / electrostrictive layer 22 is sintered, and a stable composition can be obtained. In terms of lead zirconate,
A material mainly containing lead titanate and lead magnesium niobate, or a material mainly containing sodium bismuth titanate is preferably used.

Further, lanthanum, calcium, strontium, molybdenum, tungsten, barium, niobium, zinc, nickel, manganese, cerium,
Ceramics in which oxides such as cadmium, chromium, cobalt, antimony, iron, yttrium, tantalum, lithium, bismuth, and tin are used alone or in combination may be used.

For example, when lead zirconic acid, lead titanate, and lead magnesium niobate, which are the main components, contain lanthanum and strontium, advantages such as the ability to adjust the coercive electric field and the piezoelectric characteristics can be obtained. is there.

It is desirable to avoid the addition of a material such as silica which is easily vitrified. This is because a material such as silica easily reacts with the piezoelectric / electrostrictive material during the heat treatment of the piezoelectric / electrostrictive layer 22, changes its composition, and deteriorates the piezoelectric characteristics.

On the other hand, the pair of electrodes 24 and 26 of the piezoelectric / electrostrictive elements 20a and 20b are preferably solid at room temperature and made of a metal having excellent conductivity, for example, aluminum, titanium, chromium, Simple metals such as iron, cobalt, nickel, copper, zinc, niobium, molybdenum, ruthenium, palladium, rhodium, silver, tin, tantalum, tungsten, iridium, platinum, gold, lead or alloys thereof are used. A cermet material in which the same material as the piezoelectric / electrostrictive layer 22 or the thin plate portions 12a and 12b is dispersed may be used.

The material selection of the electrodes 24 and 26 in the piezoelectric / electrostrictive elements 20a and 20b is determined depending on the method of forming the piezoelectric / electrostrictive layer 22. For example, when one electrode 24 is formed on the thin plate portions 12a and 12b, and then the piezoelectric / electrostrictive layer 22 is formed on the one electrode 24 by firing, the one electrode 24 is provided with the piezoelectric / electrostrictive layer. It is necessary to use a high melting point metal such as platinum, palladium, a platinum-palladium alloy, and a silver-palladium alloy which does not change even at the firing temperature of the piezoelectric / electrostrictive layer 22. Since the other electrode 26 formed over the layer 22 can be formed at a low temperature, aluminum,
Low melting point metals such as gold and silver can be used.

Further, since the thickness of the electrodes 24 and 26 is a factor that reduces the displacement of the piezoelectric / electrostrictive elements 20a and 20b, the electrodes formed after the piezoelectric / electrostrictive layer 22 is fired, Organometallic paste that gives a denser and thinner film after firing, such as gold resinate paste,
It is preferable to use a material such as a platinum resinate paste or a silver resinate paste.

Further, the object 18 is moved to the thin plate portions 12a and 12b.
As the adhesive 36 for fixing to the object mounting surfaces 34a and 34b, an organic resin, a brazing material, a solder or the like can be used, but when bonding at a low temperature, an organic resin is desirable, and bonding at a high temperature is preferable. Or brazing material, solder,
Glass and the like are preferred.

In the piezoelectric / electrostrictive device 10 according to the above-described embodiment, the object 18 can be used for position control, vibration prevention, etc.
It is desirable that the actuator be an object to be controlled.

The piezoelectric / electrostrictive device according to the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0063]

As described above, according to the piezoelectric / electrostrictive device according to the present invention, the size of the device can be reduced, and the device is hardly affected by harmful vibration and can perform high-speed response. It has high mechanical strength and excellent handling, impact resistance and moisture resistance.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a piezoelectric / electrostrictive device according to the present embodiment.

FIG. 2 shows a first example of the piezoelectric / electrostrictive device according to the present embodiment.
It is a perspective view which shows the modification of.

FIG. 3 shows a second example of the piezoelectric / electrostrictive device according to the present embodiment.
It is a perspective view which shows the modification of.

FIG. 4 is an explanatory diagram showing a case where both the piezoelectric / electrostrictive elements do not perform a displacement operation in the piezoelectric / electrostrictive device according to the present embodiment.

5A is a waveform diagram showing a voltage waveform applied to one piezoelectric / electrostrictive element, and FIG. 5B is a waveform diagram showing a voltage waveform applied to the other piezoelectric / electrostrictive element.

FIG. 6 is an explanatory diagram showing a case where the piezoelectric / electrostrictive element performs a displacement operation in the piezoelectric / electrostrictive device according to the present embodiment.

FIG. 7 is a configuration diagram showing a piezoelectric / electrostrictive device according to a conventional example.

[Explanation of symbols]

10, 10a, 10b: Piezoelectric / electrostrictive device 12a, 12b: Thin plate portion 14: Fixed portion 16: Ceramic base 18: Object 20a, 20b: Piezoelectric / electrostrictive element 22: Piezoelectric / electrostrictive layer 24, 26: One pair Electrodes 28, 30
... terminals 32a, 32b ... thick portions 34a, 3
4b: Object mounting surface 36: Adhesive

Claims (5)

[Claims] 1. A pair of thin plate portions facing each other and a fixing portion supporting these thin plate portions are integrally formed of ceramics, and an object is attached between the tip portions of the pair of thin plate portions. Of at least one thin plate part
A piezoelectric / electrostrictive device provided with the above piezoelectric / electrostrictive element, wherein an area of a surface of the object facing the thin plate portion is larger than an area of an object mounting surface of the thin plate portion. 2. The piezoelectric / electrostrictive device according to claim 1, wherein said piezoelectric / electrostrictive element has a film shape and is integrated with said thin plate portion by firing. device. 3. The piezoelectric / electrostrictive device according to claim 1, wherein the object is fixed to an object mounting surface of the thin plate via an adhesive. Strain device. 4. The piezoelectric / electrostrictive device according to claim 3, wherein said adhesive is made of an organic resin.
Electrostrictive device. 5. The piezoelectric / electrostrictive device according to claim 3, wherein the adhesive is made of glass, brazing material or solder.