JP2006073672A - Laminated piezoelectric crystal, its manufacturing method, piezoelectric actuator and printing head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated piezoelectric crystal which can suppress the interlayer peeling under compressive stress, its manufacturing method, a piezoelectric actuator, and a printing head equipped with the piezoelectric actuator. <P>SOLUTION: The laminated piezoelectric crystal comprises an electrode layer consisting of a silver palladium alloy on the surface and/or in the inside of a laminate, which are laminated with two or more piezo electric ceramic layers consisting of piezoelectric ceramics. The silver palladium alloy contains silver of 80 volume% or higher, the average diameter of a crystal particle of the silver palladium alloy is 0.3-5.0 μm, and the pore in the electrode layer is 10% or smaller. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laminated piezoelectric material, a manufacturing method thereof, a piezoelectric actuator, and a print head. More specifically, for example, a piezoelectric sensor such as an acceleration sensor, a knocking sensor, and an AE sensor, a fuel injection injector, a print head for an inkjet printer, and a piezoelectric resonance Laminated piezoelectric material suitable for a child, an oscillator, an ultrasonic motor, an ultrasonic vibrator, a filter, etc., and a manufacturing method thereof, a piezoelectric actuator using spreading vibration, elongation vibration, thickness vibration, and printing of characters and images The present invention relates to a print head mounted on an ink jet printer.

  Conventionally, products using piezoelectric ceramics (piezoelectric ceramics) include, for example, piezoelectric actuators, filters, piezoelectric resonators (including oscillators), ultrasonic vibrators, ultrasonic motors, piezoelectric sensors, and the like. Among them, the piezoelectric actuator has a very high response speed to the electric signal on the order of microseconds, so that it can be used as a piezoelectric actuator for positioning an XY stage of a semiconductor manufacturing apparatus, a piezoelectric actuator used for a print head of an ink jet printer, or the like. Applied. In particular, due to the recent increase in speed and cost of color printers, there is an increasing demand for the performance of ink ejection actuators such as inkjet printers.

  In response to this requirement, for example, in Patent Document 1, an electrode paste is applied and printed on the surface of a green sheet mainly composed of piezoelectric ceramics to form an internal electrode, and a plurality of green sheets are laminated and then removed. A piezoelectric actuator is produced by removing the binder contained in the green sheet and the internal electrode by binder treatment and then sintering to obtain a fired body, and further forming an insulator, external electrodes and lead wires on the fired body. It is disclosed. Such a piezoelectric actuator has a feature that a multilayer laminate of a piezoelectric ceramic layer and internal electrodes can be easily and inexpensively manufactured by simultaneous firing, and is suitable for a print head for an inkjet printer, an XY stage positioning device, and the like. Is used.

  However, the conventional piezoelectric actuator as described above has a problem in that the adhesion strength between the piezoelectric ceramic layer and the internal electrode is not always sufficient, and delamination occurs when the piezoelectric actuator is driven at a high speed.

  Therefore, in Patent Document 2 and Patent Document 3, by adding substantially the same ceramic powder (co-material) as the piezoelectric ceramic layer to the conductive paste as the internal electrode material, two layers facing each other through the internal electrode are provided. It has been proposed to increase the interlayer adhesion strength of a laminate by connecting piezoelectric ceramic layers.

  However, in the conventional piezoelectric actuators described in Patent Document 2 and Patent Document 3, since pores (cavities) remain in the electrode layer, the adhesion strength between the piezoelectric ceramic layer and the electrode layer is weak. There remains a problem that delamination occurs due to residual stress (compressive stress, tensile stress) caused by the difference in thermal expansion coefficient between the ceramic layer and the internal electrode. In addition, the laminate described in Patent Document 3 has a problem that sufficient interlayer strength cannot be obtained under use conditions in which a displacement is generated by deformation by application of a drive voltage such as an actuator.

In addition, in laminated piezoelectric materials such as piezoelectric actuators, especially when the thickness of each piezoelectric ceramic layer is 25 μm or less, the deformation due to firing becomes remarkable due to the thin thickness of the piezoelectric ceramic layer, and the dimensional accuracy Decreases and the residual stress also increases. Since this residual stress has a large effect on the d constant of the laminated piezoelectric material, an unpredictable fluctuation of the d constant occurs within one substrate. Particularly in a piezoelectric laminated body having a plurality of piezoelectric elements on the same substrate, Displacement control was difficult.
Japanese Patent Laid-Open No. 11-121820 JP 2002-260950 A JP-A-10-172855

  The subject of this invention is providing the laminated piezoelectric material which can suppress that delamination arises, its manufacturing method, a piezoelectric actuator, and a print head provided with the same.

In order to solve the above problems, a laminated piezoelectric material, a manufacturing method thereof, a piezoelectric actuator, and a print head according to the present invention have the following configurations.
(1) A laminated piezoelectric material in which an electrode layer made of a silver-palladium alloy is provided on the surface and / or inside of a laminated body in which a plurality of piezoelectric ceramic layers made of piezoelectric ceramics are laminated, wherein the silver-palladium alloy contains 80 volumes of silver. %, A silver-palladium alloy having an average crystal particle diameter of 0.3 to 5.0 μm and a pore in the electrode layer of 10% or less.
(2) The laminated piezoelectric material according to (1), wherein the piezoelectric ceramic layer has a thickness of 25 μm or less.
(3) The electrode layer contains a common material having substantially the same composition as the piezoelectric ceramic layer, and the average crystal particle size of the common material is 0.3 to 1.0 μm. Multilayer piezoelectric body.
(4) The laminated piezoelectric material according to (3), wherein the electrode layer contains 40 to 90% by volume of the silver-palladium alloy and 10 to 60% by volume of the common material.
(5) The laminate is provided with at least one electrode layer, and two piezoelectric ceramic layers facing each other through the electrode layer are connected by a common material in the electrode layer (3) or (4 ).
(6) The laminated piezoelectric material according to any one of (1) to (5), wherein the piezoelectric ceramic layer contains lead.
(7) A silver-palladium alloy powder comprising a plurality of green sheets mainly composed of piezoelectric ceramics, and having an average particle size of 0.1 to 3.0 μm and containing 80% by volume or more of silver on the surface of at least some of the green sheets. A laminate comprising a plurality of green sheets laminated to produce a laminated molded body, and the laminated molded body is pressed at a pressure of 10 to 50 MPa and then fired. A method for manufacturing a piezoelectric body.
(8) The method for producing a laminated piezoelectric body according to (7), wherein the firing temperature of the laminated molded body is 1000 ° C. or lower.
(9) A piezoelectric actuator comprising the laminated piezoelectric material according to any one of (1) to (6).
(10) A print head, wherein the piezoelectric actuator according to (9) is mounted on a flow path member in which a plurality of ink flow paths having ink ejection holes are arranged.

  The laminated piezoelectric material of the present invention is provided with a silver-palladium alloy having a predetermined amount of silver and having an average crystal particle diameter in a predetermined range as an electrode layer, and the ratio of pores in the electrode layer is kept low. The adhesion between the electrode layer and the electrode layer is high, and the delamination of these can be prevented. Thereby, a piezoelectric actuator and a print head with stable piezoelectric characteristics and easy displacement control can be obtained.

  In the method for manufacturing a multilayer piezoelectric body of the present invention, the multilayer molded body before firing is pressurized under the above-described high pressure conditions. As a result, adhesion before firing (raw adhesion) between the electrode layer and the piezoelectric ceramic layer is improved to improve adhesion after firing, and generation of pores in the electrode layer is suppressed. .

  Hereinafter, a laminated piezoelectric material according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing the multilayered piezoelectric body according to the present embodiment. As shown in FIG. 1, in this laminated piezoelectric body, an internal electrode layer 2 is provided inside a laminated body in which piezoelectric ceramic layers 1a and 1b made of piezoelectric ceramics are laminated, and a plurality of surface electrodes 3 are provided on the surface of the laminated body. Is provided. This laminated piezoelectric material can be suitably used as a piezoelectric actuator by connecting a lead wire to the surface electrode 3 and making an electrical connection to the outside.

  In the present invention, the internal electrode layer 2 co-fired with the ceramic layers 1a and 1b is made of a silver-palladium alloy, and silver is 80% by volume or more, preferably 85% by volume, more preferably 90% by volume or more, and still more preferably 93%. It is good that it is more than volume%. The upper limit of silver in the silver-palladium alloy is 99.9% by volume, preferably 97% by volume, more preferably 95% by volume.

  The internal electrode layer 2 having such a composition has high wettability with the piezoelectric ceramic and can improve the adhesion strength. Further, the residual stress between the piezoelectric ceramic layers 1a and 1b and the internal electrode layer 2 can be reduced. It is preferable to control the magnitude of the residual stress generated in the laminated piezoelectric body after firing to 100 MPa or less. In particular, a higher effect of reducing residual stress caused by contraction of the electrode can be expected by setting the silver ratio to 90% by volume or more. Therefore, the present invention is particularly effective for a thin laminated piezoelectric body that is easily affected by deformation and residual stress during firing.

  Moreover, in order to suppress aggregation of the internal electrode layer 2, the average crystal particle diameter of the silver palladium alloy in the internal electrode layer 2 is 0.3 to 5.0 μm, preferably 0.5 to 3.0 μm, more preferably 1 It is good that it is 0.0-2.0 micrometers. The average crystal particle diameter of the silver-palladium alloy is determined by a code method from a photograph (magnification 3000 times) obtained by observing the electrode surface with a scanning electron microscope (SEM).

  The surface electrode 3 can be simultaneously fired with the ceramic layers 1a and 1b and the internal electrode layer 2, but after the ceramic layers 1a and 1b and the internal electrode layer 2 are simultaneously fired, the surface electrode 3 is separately provided on the surface of the obtained sintered body. It can also be formed. Therefore, when the surface electrode 3 is simultaneously fired with the ceramic layers 1 a and 1 b and the internal electrode layer 2, it is preferable to use a silver-palladium alloy containing silver in the above-described ratio as the material of the surface electrode 3. On the other hand, when the surface electrode 3 is fired separately from the ceramic layers 1a and 1b and the internal electrode layer 2, as a material for the surface electrode 3, gold, platinum, copper, aluminum, and alloys thereof in addition to the silver-palladium alloy. Etc. can be used.

  Further, in order to further increase the adhesion strength between the ceramic layers 1a and 1b and the electrode layer, reduce the residual stress, and further stabilize the piezoelectric characteristic d31, at least a part of the electrode layer, particularly the internal electrode layer 2, is piezoelectric. It is preferable to contain a piezoelectric ceramic (co-material) having substantially the same composition as the ceramic layers 1a and 1b. This common material is contained in a proportion of 10 to 60% by volume, particularly 18 to 50% by volume, and further 20 to 30% by volume when the total amount of the silver-palladium alloy is 100% by volume. This is preferable in that the residual stress is reduced while increasing the adhesion strength between 1b and the internal electrode 2.

  Further, the average crystal particle diameter of the common material is preferably 0.3 to 1.0 μm for homogenizing the residual stress, and more preferably 0.4 to 0.6 μm for suppressing defects. preferable. When the crystal grain size is controlled in this way, even when residual stress is generated, the residual stress generated in the plurality of displacement elements is made uniform, the variation is reduced, and the influence on the piezoelectric characteristic d31 is reduced. . The average crystal particle diameter of the common material is determined by a laser diffraction scattering method.

  In addition, it is preferable that the two piezoelectric ceramic layers 1 a and the piezoelectric ceramic layer 1 b facing each other through the internal electrode layer 2 are connected by a common material in the internal electrode layer 2. The code | symbol 4 in FIG. 1 has shown the common material which connects ceramic layer 1a, 1b. By connecting the piezoelectric ceramic layers 1a and 1b in this way, the effect of suppressing delamination during displacement is further enhanced.

  Further, in order to suppress the occurrence of delamination under compressive stress and to suppress variations in piezoelectric characteristics, the ratio of the pores 5 in the internal electrode layer 2 shown in FIG. 4 is 10% or less, preferably 6% or less. More preferably, it is 3% or less. The ratio of the pore 5 is obtained by observing a cross section of the mirror-polished laminated piezoelectric body using a scanning electron microscope (SEM) or the like, and determining the ratio of the area of the pore to the cross sectional area of the electrode.

  The thickness of the internal electrode layer 2 needs to be conductive and not to prevent displacement, and is generally about 0.5 to 5 μm, preferably 1 to 4 μm. Moreover, the thickness of the surface electrode 3 needs to be a grade which has electroconductivity and does not prevent a displacement, and generally is about 0.1-2 micrometers, Preferably it is 0.1-0.5 micrometer.

  In the present invention, the piezoelectric ceramic means a ceramic exhibiting piezoelectricity, such as a Bi layered compound, a tungsten bronze structure material, a perovskite structure compound of an alkali Nb acid compound, lead zirconate titanate (PZT) or titanium containing Pb. Although perovskite structure compounds containing lead acid etc. can be exemplified, among these, lead zirconate titanate and lead titanate containing Pb are suitable in terms of increasing wettability with the electrode and increasing adhesion strength with the electrode. .

  That is, it is a crystal containing Pb as an A site constituent element and Zr and / or Ti as a B site constituent element. In particular, a lead zirconate titanate-based compound has a higher d constant. This is preferable for obtaining a stable piezoelectric sintered body.

The piezoelectric ceramic layers 1a and 1b preferably contain at least one of Sr, Ba, Ni, Sb, Nb, Zn, Yb, and Te as subcomponents. Thereby, a more stable piezoelectric sintered body can be obtained. For example, as a subcomponent, what is formed by dissolving Pb (Zn _1/3 Sb _2/3 ) O ₃ and Pb (Ni _1/2 Te _1/2 ) O ₃ can be exemplified.

  In particular, it is desirable to further contain an alkaline earth element as the A site constituent element. As the alkaline earth element, Ba and Sr are particularly preferable in that a high displacement can be obtained, and the inclusion of 0.02 to 0.08 mol of Ba and 0.02 to 0.12 mol of Sr is particularly mainly tetragonal composition. It is advantageous to obtain a large displacement in the case of the following composition.

For _{example, Pb 1-xy Sr x Ba} y (Zn 1/3 Sb 2/3) a (Ni 1/2 Te 1/2) b Zr 1-abc Ti c O 3 + αwt% Pb 1/2 NbO 3 (0 ≦ x ≦ 0.14, 0 ≦ y ≦ 0.14, 0.05 ≦ a ≦ 0.1, 0.002 ≦ b ≦ 0.01, 0.44 ≦ c ≦ 0.50, α = 0.1 -1.0).

  The thickness of the piezoelectric ceramic layers 1a and 1b is preferably 1 to 50 μm. In particular, the thickness t of the ceramic layer 1b located between the internal electrode layer 2 and the surface electrode 3 is preferably 25 μm or less. The total thickness T of the laminated piezoelectric material is not particularly limited, but is preferably 100 μm or less, preferably 80 μm or less, in that a large displacement can be obtained and high-efficiency driving can be realized at a low voltage. More preferably, it is 65 μm or less, and further preferably 50 μm or less. On the other hand, the lower limit of the thickness T is 3 μm, preferably 5 μm, more preferably 10 μm, and even more preferably 20 μm in order to have sufficient mechanical strength and prevent breakage during handling and operation.

  By combining the piezoelectric ceramic layer and the electrode layer as described above, it is possible to suppress the deformation, suppress the in-plane variation of the piezoelectric characteristics d31, and obtain a laminated piezoelectric body that can easily control the displacement. In the conventional piezoelectric actuator, when an AC signal having a frequency of 20 KHz is applied and driven, there is a problem that the displacement stops in about 3 hours. For example, the actuator comprising the laminated piezoelectric material of the present invention shown in FIG. If the same alternating current signal is applied to drive and the displacement characteristic is stabilized, the above problem can be solved.

Next, the manufacturing method of the laminated piezoelectric material of the present invention will be described by taking as an example the case of using PZT as the piezoelectric ceramic.
First, as a raw material, a PZT powder having a purity of 99% and an average particle diameter of 1 μm or less is prepared as a piezoelectric ceramic powder. An appropriate organic binder is added to the piezoelectric ceramic powder and formed into a tape shape to produce a plurality of green sheets. Next, a conductor paste containing silver palladium alloy powder having an average particle diameter of 0.1 to 3.0 μm and containing 80% by volume or more of silver is applied to the surface of some green sheets. Next, each green sheet (a green sheet coated with a conductive paste and a green sheet not coated) is laminated in a predetermined order to prepare a laminated molded body, and the laminated molded body is pressed at a pressure of 10 to 50 MPa. If necessary, cut it into a desired shape. This is subjected to binder removal treatment at about 400 ° C., and then fired at about 900 to 1100 ° C., preferably 900 to 1000 ° C. The firing temperature is preferably 1000 ° C. or lower. After firing, one or more surface electrodes are formed on the surface and polarized to obtain a laminated piezoelectric body.

As described above, the adhesiveness (bioadhesion) before firing between the electrode layer and the piezoelectric ceramic layer is improved by pressurizing the laminated molded body before firing under the above-described high pressure conditions. Thereby, while improving the adhesiveness after baking, it suppresses that a pore generate | occur | produces in an electrode layer. The laminated molded body preferably has a density (green density) before firing of 4.5 g / cm ² or more. By increasing the green density to 4.5 g / cm ² or more, firing at a lower temperature becomes possible, and when the green density is further increased, evaporation of Pb can be suppressed.

  In the case of producing a laminated molded body by laminating green sheets, a constraining sheet composed of a piezoelectric ceramic and an organic composition having substantially the same composition as the green sheet is disposed on both sides or one side of the laminated molded body. It is preferable to press and adhere with. In this way, by suppressing the shrinkage of the outer green sheet with the restraint sheet, an effect of reducing warpage of the laminated molded body can be expected, and stress during adhesion to the support member can be reduced.

  The laminated piezoelectric material of the present invention can be suitably used as a piezoelectric actuator mounted on an inkjet print head. For example, the inkjet print head shown in FIGS. 2A and 2B includes a flow path member in which the piezoelectric actuator 15 includes an ink flow path 16a having an ink discharge port 18 and a partition wall 16b that partitions each ink flow path 16a. 16 is joined. The piezoelectric actuator 15 is configured such that an internal electrode layer 12, a piezoelectric ceramic layer 11b, and a surface electrode 13 are laminated in this order on a vibration plate 11a, and a plurality of surface electrodes 13 are arranged on the surface of the piezoelectric ceramic layer 11b. A plurality of displacement elements 14 composed of the internal electrode layer 12, the surface electrode 13, and the piezoelectric ceramic layer 11b positioned therebetween are formed.

  The piezoelectric actuator 15 and the flow path member 16 are bonded to the flow path member 16 with an adhesive or the like so that the vibration plate 11a contacts the space of the ink flow path 16a. At this time, each surface electrode 13 is disposed so as to correspond to each of the ink flow paths 16a.

  The diaphragm 11a may be any material having high insulation, but is preferably piezoelectric ceramic, and more preferably substantially the same material as the piezoelectric ceramic layer 11b. Thereby, when the diaphragm 11a and the piezoelectric ceramic layer 11b are produced by simultaneous firing, firing shrinkage in the piezoelectric actuator can be made uniform, so that warpage deformation can be suppressed.

  When a voltage is applied from the drive circuit between the surface electrode 13 and the internal electrode 12, the displacement element to which the voltage is applied displaces and vibrates to pressurize the ink in the corresponding ink flow path 13a, and the flow path member 16 Ink droplets are ejected from the ink ejection holes 18 opened on the bottom surface of the ink.

  By using the laminated piezoelectric material of the present invention as an actuator for such a print head, a print head can be realized using an inexpensive IC. Since this print head is excellent in displacement characteristics, it is characterized by high-speed and high-precision ejection, and is suitable for high-speed printing. In addition, a printer including an ink tank that supplies ink to the print head and a recording paper transport mechanism for printing on recording paper can easily achieve high-speed and high-precision printing as compared with the conventional printer.

  As mentioned above, although one Embodiment of this invention was shown, it cannot be overemphasized that this invention can be applied not only to the embodiment mentioned above but what was changed and improved in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the case where the laminated piezoelectric body is applied to a piezoelectric actuator and an inkjet print head has been described. However, the laminated piezoelectric body of the present invention may be a piezoelectric sensor such as an acceleration sensor, a knocking sensor, or an AE sensor, The present invention can also be applied to fuel injectors, piezoelectric resonators, oscillators, ultrasonic motors, ultrasonic vibrators, filters, and the like.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further in detail, this invention is not limited to a following example.
The laminated piezoelectric material of the present invention was produced and applied to an inkjet print head as an actuator.

  First, as raw materials, a piezoelectric ceramic powder (sample No. 1 to 21, 24 to 26) containing lead zirconate titanate having a purity of 99% or more, a piezoelectric ceramic powder containing lead titanate (sample No. 22), Alternatively, a piezoelectric ceramic powder (sample No. 23) containing barium titanate was prepared.

  Next, butyl methacrylate as an aqueous binder, polycarboxylic acid ammonium salt as a dispersant, isopropyl alcohol and pure water as a solvent are added to the piezoelectric ceramic powder and mixed, and this slurry is applied to a carrier film by a doctor blade method. Green sheets were formed by forming into 30 μm thick sheet shapes.

  Next, a conductor paste for an internal electrode containing silver and a silver palladium alloy having an average particle diameter shown in Table 1 at a ratio shown in Table 1 was prepared. To this conductor paste, ceramic powder shown in Table 1 was added as a co-material. These silver palladium alloy and the co-material were separately mixed with a vehicle containing an organic binder and an organic solvent, and then both were sufficiently kneaded to prepare a conductor paste.

  The obtained conductor paste was printed on the surface of the green sheet with a thickness of 4 μm to form an internal electrode layer. Furthermore, the surface on which the internal electrode layer is printed is faced upward, and a green sheet on which the internal electrode paste is not printed is laminated thereon to produce a laminated molded body. The laminated molded body is formed at the lamination pressure described in Table 1. After pressurizing and pressurizing, it was degreased and fired at the temperature shown in Table 1 for 4 hours in an atmosphere of 99% oxygen or more.

  Next, a plurality of surface electrodes 3 were formed on one surface of the sintered body. The surface electrode 3 applied Au paste by screen printing. This was formed by baking at 600 to 800 ° C. in the air. Finally, lead wires were connected to the surface electrode 3 by soldering to obtain piezoelectric actuators each including a laminated piezoelectric body having a shape as shown in FIG.

Next, a piezoelectric element whose d constant and adhesion strength are evaluated will be described.
<D31, Cv value>
The laminated piezoelectric material obtained above was cut into 10 cm × 10 cm, and only one side was polished to leave only one piezoelectric ceramic layer. Then, electrodes were formed on both main surfaces of the porcelain by Au vapor deposition. Then, it was cut out by dicing into a long side direction of 12 mm and a short side direction of 3 mm, and polarization was performed by applying a DC voltage of 3 kv / mm in the thickness direction for 5 minutes. The element was measured for resonance frequency, antiresonance frequency, resonance resistance, antiresonance resistance, and capacitance with an impedance analyzer (Agilent Technology 4194A), and d31 was calculated from the density measured by the Archimedes method. Then, the standard deviation (σ) value (σ / average value) × 100 with respect to the average value of d31 of the six elements was defined as the Cv value. A case where the Cv value was 1.5 or less was regarded as a non-defective product.

<Occurrence of pores>
The pore ratio in the internal electrode is determined by mirror-polishing the porcelain cross section and taking a picture at a magnification of 3000 times using a scanning electron microscope (SEM). The ratio of the area occupied by pores to the area) was determined.

<Occurrence of delamination>
The fired piezoelectric ceramic substrate was cut into a shape of 8 mm × 8 mm, and adhered to a metal substrate having a thermal expansion coefficient of 1 × 10 ⁻⁵ or higher at 100 ° C. or higher with an adhesive. At room temperature, a compressive stress of about 20 MPa due to the difference in thermal expansion between the substrate and the metal substrate is applied. Then, the occurrence of peeling was promoted by striking a Vickers indentation on the substrate surface under conditions of 5 kgf and 5 seconds. The peel strength was compared based on the peel occurrence rate when 40 Vickers indentations were hit, and a 0% peel occurrence was determined as a good product.
Each evaluation result is shown in Table 1.

  As shown in Table 1, sample No. In the laminated piezoelectric bodies of Nos. 2 to 20 and Nos. 22 to 26, the Cv value of d31 was 1.5% or less, and the number of occurrences of peeling was 0%. On the other hand, sample no. 1 and 21, the Cv of d31 was as large as 2% or more, and the number of occurrences of peeling was 10% or more.

It is a schematic sectional drawing which shows the laminated piezoelectric material of this invention. (a) is an enlarged sectional view showing a print head equipped with the piezoelectric actuator of the present invention, and (b) is a plan view showing the print head equipped with the piezoelectric actuator of the present invention.

Explanation of symbols

l, 11b ... Piezoelectric ceramic layer 2 ... Internal electrode 3 ... Surface electrode 11a ... Diaphragm 12 ... Common electrode 13 ... Individual electrode 14 ... Displacement element 15 ... Piezoelectric Actuator 16 ... flow path member 16a ... ink flow path 16b ... partition 18 ... ink ejection hole

Claims (10)

A laminated piezoelectric body in which an electrode layer made of a silver-palladium alloy is provided on the surface and / or inside of a laminated body in which a plurality of piezoelectric ceramic layers made of piezoelectric ceramics are laminated,
The silver-palladium alloy contains 80% by volume or more of silver, the average crystal particle diameter of the silver-palladium alloy is 0.3 to 5.0 μm, and the ratio of pores in the electrode layer is 10% or less. Laminated piezoelectric material.   The multilayer piezoelectric body according to claim 1, wherein the thickness of the piezoelectric ceramic layer is 25 μm or less.   3. The multilayered piezoelectric body according to claim 1, wherein the electrode layer contains a co-material having substantially the same composition as the piezoelectric ceramic layer, and the co-material has an average crystal particle diameter of 0.3 to 1.0 μm.   The laminated piezoelectric material according to claim 3, wherein the electrode layer contains 40 to 90% by volume of the silver-palladium alloy and 10 to 60% by volume of the common material.   5. The laminated piezoelectric element according to claim 3, wherein at least one electrode layer is provided in the laminated body, and two piezoelectric ceramic layers facing each other through the electrode layer are connected by a common material in the electrode layer. body.   The multilayer piezoelectric body according to claim 1, wherein the piezoelectric ceramic layer contains lead.   A plurality of green sheets mainly composed of piezoelectric ceramics are produced, and silver palladium alloy powder containing an average particle size of 0.1 to 3.0 μm and containing 80% by volume or more of silver is contained on at least a part of the green sheets. A laminated piezoelectric material comprising: applying a conductive paste; laminating a plurality of the green sheets to produce a laminated molded body; pressurizing the laminated molded body at a pressure of 10 to 50 MPa; and firing the laminated molded body. Production method.   The method for producing a multilayer piezoelectric body according to claim 7, wherein a firing temperature of the multilayer molded body is 1000 ° C. or less.   The piezoelectric actuator provided with the laminated piezoelectric material in any one of Claims 1-6. 10. A print head, wherein the piezoelectric actuator according to claim 9 is mounted on a flow path member in which a plurality of ink flow paths having ink discharge holes are arranged.

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