JPH02284483A - Laminated piezoelectric element and its manufacture - Google Patents

Abstract

PURPOSE:To prevent the generation of short-circuiting of electrodes even in a high humidity atmosphere, and obtain high reliability at a low operating voltage, by a method wherein piezoelectric ceramics layers wherein baking is finished and electrode layers are alternately laminated, heated at a low temperature, and bonded. CONSTITUTION:A green sheet is made by using paste obtained by mixing piezoelectric ceramics powder with solvent; by molding and sintering the green sheet, a piezoelectric ceramics substrate 1 is obtained; a lamination body is formed by using a plurality of the substrates, arranging electrode plates 2a, 2b between the substrates, and performing heating and pressing. outward leading-out terminals 3a, 3b are formed at two portions of the side surfaces of the lamination body; the plates 2a, 2b are alternately connected, every other layer, with the terminals 3a, 3b. At this time, exposed end-portions of the electrode plates 2a, 2b are turned into electrically insulative compound 4a, 4b. As to each of the electrode plates 2a, 2b, skin material 22 of aluminum alloy or nickel alloy is formed on both surfaces of core material 21 of aluminum or nickel.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a laminated piezoelectric element, and a piezoelectric actuator with a full-surface electrode structure that has excellent moisture resistance, particularly low operating voltage, and excellent reliability and productivity. It is related to.

[Conventional technology]

Piezoelectric ceramics have the property of converting mechanical energy and electrical energy, and their application to sensors and actuators for detecting mechanical quantities is being actively developed. However, since the elongation rate of piezoelectric ceramics per applied voltage is small, it is necessary to apply a very large direct pressure to obtain a practical displacement. Therefore, a method is often used in which the applied voltage is lowered by making the thickness of the piezoelectric ceramic as thin as possible and laminating a large number of piezoelectric ceramics. A piezoelectric element having such a structure is called a laminated piezoelectric element.

The clean sheet method is the most advanced manufacturing technology for laminated piezoelectric elements. In this method, piezoelectric material powder is dispersed in a suitable solvent, the resulting slurry is formed into a sheet, a metal paste is applied as an electrode by screen printing, etc., and then a number of sheets are laminated. Drying and sintering are performed. With this manufacturing method, the applied voltage to obtain the typical maximum elongation rate of piezoelectric elements of 0.1%]
, 00■. Known examples of laminated piezoelectric cords made by the conventional green sheet method include, for example, Japanese Patent Publication No. 5932040 and Sensor Technology Vol. 3, No. 12 (1983), No. 31.
There are papers listed on the page.

In addition, as an electrode structure that reduces the internal stress of the laminated pressure element and improves its reliability, a full-surface electrode structure in which the area of the piezoelectric ceramic and the electrode are equal is used.
It is described in the publication No.-17354. Cross-sectional views of the full-surface electrode type laminated piezoelectric element are shown in FIGS. 7 and 8. FIG. 8 is a sectional view 1f11 taken along line A-A in FIG. 7.

In addition, as a related prior art example of the present invention, Japanese Patent Application Laid-Open No. 62-
No. 62571, No. 6]-27688, and the like.

[Problem to be solved by the invention]

In the former conventional technique, the sintering of the clean sheets 1 to 1 of the piezoelectric ceramic plate and the lamination with the electrodes 2 are performed simultaneously at about 1300°C. Therefore, noble metals that are stable at high temperatures, especially silver-palladium (AgPd) alloys, were often used for the monthly charges for Den 4@2. However, the piezoelectric element using the silver-palladium alloy electrodes has a problem in that short circuits occur between the electrodes when operated in a humid atmosphere. This Ih'l
The reason may be that water penetrates into the molding resin 5 that protects the side surfaces of the piezoelectric element and conducts between the electrodes, or
This is because a layer of water is formed between the laminate and the resin 5, and silver is eluted into the layer as ions (Ag+), or it is attracted by the electric field and deposited near the adjacent electrode, forming a conductive path. think. This phenomenon is generally called micrasion. Silver rM, f4! This is a common problem for electrical components that use

On the other hand, the latter conventional technology, the full electrode method
In the type piezoelectric element, as shown in FIG. 7, in order to alternately connect the electrodes 2 and external lead terminals 3,
A method is used in which an insulating material 4 is coated along the edges of the material. However, in this method, it is necessary to make the width and thickness of the insulator 4 sufficiently large compared to the thickness of the electrode 2 in order to increase the dielectric strength, so the distance between the electrodes or the thickness of the piezoelectric ceramic board must be made small. This poses a problem in that it becomes difficult to reduce the operating voltage. Furthermore, since the lead terminals 3 are formed on the unevenness of the insulator 4, there is a problem in their reliability. To further complicate the process,
There is also the problem that the yield is low and the production cost 1- is high.

An object of the present invention is to provide a structure of a low-cost, all-over electrode type multilayer piezoelectric element that does not cause electrode short circuits even in a humid atmosphere, has particularly low operating voltage, and is excellent in reliability.

[Means to solve the problem]

In order to achieve the above objective, aluminum or an alloy mainly composed of aluminum as the gold plate serving as the electrode,
Alternatively, a single-layer or multi-layer flat plate selected from nickel or an alloy containing nickel as a main component is used, and the metal plate is alternately brought into electrical contact with one of a pair of lead terminals, and the other is electrically contacted with the other. The boundary between the riser terminal and the molding resin was chemically changed to an electrically insulating compound.

The above means is particularly effective for a so-called full-surface electrode type laminated piezoelectric element in which the area of the piezoelectric ceramic plate and the metal plate are equal.

The piezoelectric element of the present invention, its manufacturing method, or its application examples have the following features.

(1) A pair of external lead-out terminals is attached to the side surface of a laminate of a plurality of piezoelectric ceramic plates and a metal plate interposed between each of the piezoelectric ceramic plates, and the metal plate is made of aluminum. , alumina 11-layer alloy, nickel, and nickel-based alloy t) In the laminated piezoelectric cable f, which is a flat plate of one layer or multiple layers, the metal plate is alternately electrically connected to one of the lead terminals. contact, and the other glue-1 terminal and the metal plate are not in electrical contact °C1
The non-contact end thereof shall be an electrically insulating compound substituted for the gold) ρ of the plate.

(2) A pair of lead terminals for external extraction is attached to the side surface of a laminate of a plurality of piezoelectric ceramic plates and a metal plate interposed between the piezoelectric ceramic plates, and the metal plate is oxidized and/or In a laminated pressure f4i element which is a single-layer or multi-layer flat plate made of an active metal or an alloy mainly composed of active gold II which becomes chemically stable by nitriding, the gold 1pt
The plates are alternately brought into electrical contact with only one of the lead terminals 1'I', and the other terminal and the metal plate are not in electrical contact with each other, with the non-contact end being in electrical contact with the metal plate. It is a substitute for an electrically insulating compound on a metal plate.

(3) A laminated piezoelectric element comprising a laminate of a plurality of piezoelectric ceramic plates and a metal plate interposed between the piezoelectric ceramic plates, and a pair of external lead-out terminals attached to the side surface of the laminate, in which the metal The plates are electrically contacted alternately with one of the lead terminals, and the other terminal and the metal terminals r+f are electrically not in contact with each other, and the non-contact portion is free from oxidation of the metal plate material. and/or nitride.

(4) The electrically insulating compound is anodized aluminum,
Must be selected from anodized nickel, plasma discharge aluminum nitride, and plasma discharge nickel nitride.

(5) The side 1-fI of the laminate is coated with resin for molding.

(6) The piezoelectric ceramic plate and the metal plate have substantially the same planar dimensions.

(Mon) (7) The alloy applied to the metal plate is characterized in that silicon, magnesium, gel manila 11, or a mixture thereof is dissolved in alumina 11 as a solid solution.

(8) The alloy applied to the metal plate is one in which chromium, palladium, copper, or a mixture thereof is dissolved in nickel.

(9) A heater is attached to the outside of the laminate.

(1,0) Force received by each of the electrically insulating compound titanium metal body at plates.

to be located in

(11) In a mass flow controller 1 roller equipped with a flow channel throttling adjustment mechanism in the flow path of the fluid, the adjustment mechanism groove is composed of a diaphragm that flows into the flow path and a piezoelectric element connected to the diaphragm. , the piezoelectric element is
]) Nomu (9).

(J2) In an injection valve in which a fuel flow path that moves with the movement of the cylinder and a fuel flow path formed in an outer cylinder in which the cylinder is housed are connected and disconnected by the movement of the cylinder, a drive means for the cylinder. As mentioned above (1
) to (9).

03) A laminate type characterized in that a laminate is formed by laminating a plurality of piezoelectric ceramic plates with metal plates interposed between them, and then a pair of lead terminals for external extraction are attached to the side surfaces of the laminate. In the method for manufacturing a piezoelectric element, after the metal plates are laminated between piezoelectric ceramic plates, the ends of the metal plates are anodized and cut every other layer, and the anodized parts and the untreated ends of the metal plates are directly covered. One lead terminal is formed in this manner, and then the other end surface of the untreated metal plate end is anodized to form the remaining lead terminals.

(14) Performing plasma open-air nitriding treatment instead of anodic oxidation treatment.

The laminated piezoelectric device (for example, an actuator, a sensor) of the present invention has, for example, an external lead that brings together ten poles of each electrode of the piezoelectric element, and an external lead that brings together the negative poles, which are attached to the side surface of the piezoelectric element. It is something.

(]3) The method for manufacturing the laminated piezoelectric element of the present invention involves alternately laminating layers of fired piezoelectric ceramic material and "city pole layers" and then heating at a temperature lower than the firing temperature of the piezoelectric ceramic material, or by heating and heating.
By applying pressure and holding it for a predetermined period of time, bonding, particularly preferably diffusion bonding, is performed.

What is fired piezoelectric ceramics?Piezoelectric ceramics Grinshi-1
- is fired.

In addition, it is preferable to cool down without removing the pressure after the bonding process, and in particular, in the cooling process after bonding = 1, a voltage is applied at a temperature 20 to 70°C higher than the Curie point of the piezoelectric ceramics. It is desirable to polarize the ceramics. Here, the Curie point refers to the temperature at which piezoelectric ceramics lose their properties, and polarization refers to a processing step of ceramics to form a piezoelectric element.

In general, piezoelectric ceramic materials are ferroelectric materials that have a Belogesky 1-type crystal structure, and exhibit a cubic crystalline phase at temperatures above the Curie point, and a crystalline phase more deformed than cubic at temperatures below the Curie point. 4) In other words, polarity (directivity) occurs in the structure. Piezoelectric ceramics immediately after firing is an aggregate of crystal grains, and portions with different polarities coexist within each crystal grain. In the state of pressurized ceramitas that has just been fired, each crystal grain has a polarity of 1-
The total sum is zero, and the whole is free from fraud.

By applying an electric field of constant Ir to this, the direction of polarity is determined for each crystal grain, and this is called polarization, and such processing is called polarization processing.

The electrode material may be used in the form of film, foil, or paste, but as a conventional technology, pure aluminum 1
1. Preferred are nickel, alumina 11 thread alloy, and nickel-based alloy. This is because unlike silver, it does not undergo migration. From the same point of view, platinum (Pt) and 1. Jd
(palladium) can also be applied. Furthermore, if an aluminum electrode is used, it is preferable to use a three-layer structure in which the image surface material is an aluminum-silicon alloy and the layer phase is aluminum.

Note that the laminated state is not limited to laminated layers, but may be a cylindrical layered product.

Polarization causes the piezoelectric ceramic itself to increase in volume and generate large internal stress. Therefore, if a polarization treatment is performed during cooling,
Volume contraction due to cooling and volume increase due to polarization: 'l'
Internal strain (internal stress) is alleviated by the repulsion, and the strength reliability of piezoelectric ceramics is improved.

When pure/Luminium 11 or an aluminum-based alloy is used as the electrode metal, the lamination temperature (junction temperature) can be lowered to a very low level, so that the generation of thermal stress is small. Furthermore, since aluminum is an active metal, bondability with piezoelectric ceramics is improved.

Furthermore, the present invention is easy to manufacture because the insert material for contacting the piezoelectric ceramic layer phase BH also serves as the electrode material.

[Effect]

The main point of the present invention is to use aluminum or nickel as the electrode material. Aluminum and nickel are very active metals when working with hard surfaces.
It has a property jcT that changes to a chemically stable so-called passive state when the surface is oxidized or nitrided. Therefore J:
Utilizing the active surfaces of both metal materials, sintered piezoelectric ceramic plates can be stacked together by bonding, and the metal materials can be used as electrodes as they are. At that time, if a stabilizing treatment is applied to the exposed side of the laminate, electrical conduction will not occur even if it gets wet during operation in a humid atmosphere, and ions will not form in the water. Elution and migration will no longer occur.

In particular, when the present invention is applied to a laminated piezoelectric element of a full-surface electrode type in which electrodes are formed on the entire surface of a piezoelectric ceramic plate, an insulator can be formed without creating unevenness on the side surface of the element. Therefore, the thickness of the piezoelectric ceramic can be reduced and the operating voltage can be lowered. Furthermore, since the lead terminal is formed on the flat side surface, its reliability is improved.

Furthermore, the process becomes simpler, which improves productivity.

〔Example〕

An embodiment of the present invention will now be described with reference to FIG. FIG. 1 is a perspective view of a laminated piezoelectric element according to the present invention in a state before its side surface is coated with a molding resin. Further, FIG. 2 is a sectional view taken along planes A and B C of the element shown in FIG. 1.

Dielectric ceramics that have the property of generating electrical polarization when stress is applied, that is, piezoelectricity, are called piezoelectric ceramics, and barium titanate (Ilai'j-D, q) r
Lead titanate (PbT, Os) + lead zirconate titanate (Pb(Zr,Ti)08) and the like are popular.

A green sheet is made from a paste obtained by mixing these piezoelectric ceramic powders with a solvent, and a plurality of piezoelectric ceramic plates 1 obtained by forming and sintering the green sheet are made into a plurality of piezoelectric ceramic plates 1 as shown in FIGS. 1 and 2. electrode plates 2a and 2b are arranged between each layer, h'<+: L/, and a laminate is obtained by heating and pressurizing. Electrode plates 2 are placed at two locations on the side of this laminate.
Lead terminals 3a and 3b for external extraction of electrodes a and 2b are formed, and an electrode plate 2a is formed.

2b are alternately connected to lead terminals 3a and 3b on every other layer. At this time, the end surfaces of the electrodes 2a, 2b that are exposed on the side surfaces of the laminate are changed to an electrically insulating compound 4a, 4b, for example, an oxide or a nitride. As shown in the figure, the electrode 2a connected to the lead terminal 3a is coated with an electrically insulating compound 4a at its boundary to prevent electrical contact with the lead terminal 3b, and the electrode 2b connected to the lead terminal 3b is coated with an electrically insulating compound 4a to prevent electrical contact with the lead terminal 3b. In order to prevent electrical contact, the boundary portion is changed to an electrically insulating compound 4b.The material of each electrode plate 2a, 2b is aluminum, an alloy of aluminum with silicon, magnesium, or germanium dissolved in solid solution, or nickel or nickel. The alloy is selected from alloys in which chromium, palladium, or copper is dissolved in nickel.A particularly desirable configuration is shown in FIG. It is formed.

The following effects can be obtained by adopting the electrode material and insulating structure as described below.

First, when using an electrode mainly composed of aluminum,
Heating temperature 58 when forming a laminate by heating and pressurizing
At 0 to 660°C, only the skin layer of the electrode becomes a liquid phase, so
The oxide film on the surface of the Aluminum 11 alloy electrode is destroyed, and the active liquid phase of the Aluminum 11 alloy promotes adhesion and reaction with the piezoelectric ceramic. On the other hand, Shingetsu's aluminum remains in a solid phase, maintaining a constant electrode thickness. When using nickel electrodes, the appropriate heating temperature or different ordering)
The following principle is the same as for aluminum.

Next, by changing the end face of the electric strainer used for laminating the piezoelectric ceramic plates to an insulating material, there is no longer a restriction on the thickness of the piezoelectric ceramic plate 1 in the conventional example (Fig. 7), and the operating voltage can be reduced. The reduction was 71<.Also, unlike the conventional example, since the side surfaces of the laminate are flat, the shape of the lead terminal 3 is smooth and the incidence of wire breakage is low.

Furthermore, many I! lI! Even if water penetrates during operation in a comfortable atmosphere, the incidence of migration and short circuit of the electrode 2 is reduced.

Next, a method for manufacturing a laminated piezoelectric element will be explained using FIG. a) Molded and sintered piezoelectric ceramic] and aluminum alloy electrodes 2a and 2b are crossed 11. After overlaying it, hora 1
0.2 to 1 kg in an argon atmosphere using a hepress
Heat to 600"C while pressurizing at 1/mm" pressure.
After holding for a time to form a laminate and polishing the side surfaces, electrodes 3' were formed on the side surfaces where the electrodes 2a were exposed every other layer. b) The electrode 3' was anodized. Then, the end surface of the electrode 2a that is in contact with the electrode 3' changes to an oxide 4a. C) This laminate was cut vertically to form a full-surface electrode structure in which electrodes 2a and 2b had the same area. The figure is b
) is seen from the right side, and the oxide 4a is shown protruding to make the position clear. d) Terminals 1 to 3a were formed on the side surfaces where the oxides 4a and electrodes 2b were alternately present, and brought into electrical contact with the electrodes 44!2b. e) The lead terminal 3a was anodized. Then, the end surface of the electrode 2b that is in contact with the lead 1 (the terminal 3a) changes into an oxide 4b.

f) Lead terminals 3b were formed on the side surfaces where the electrodes 2a and oxides 4b with exposed metal parts were alternately present, and brought into electrical contact with the electrodes 28. After this, although not shown in the drawings, a lead wire for voltage application was connected to the lead terminal 3, and the side surface of the laminate was covered with molding resin (2). Finally, a polarization process was performed to impart a predetermined piezoelectricity, resulting in a product kIIJ('I piezoelectric element).

Note that when a nickel alloy is used for the electrode 2, the heating temperature is ]]-〇〇~] 300°C.

In addition, even if an insulating structure is adopted using the conventional method without selectively oxidizing the electrodes by anodic oxidation, the electrodes exposed on the sides of the laminate may be removed before the laminate is coated with molding resin. By oxidizing or nitriding the end face using, for example, glow discharge plasma, it is effective to prevent short-circuiting of the electrodes during operation in a humid atmosphere.

In the embodiment shown in Section 2, the end ifn of the electrode was smooth, but another embodiment different from that will be described with reference to FIG. When the piezoelectric ceramic 1 and the electrode 2 are laminated, if the heating temperature is made higher than the melting point of the electrode 2, the electrode 2 will melt and protrude from the side surface of the laminate as shown in FIG. The electrode 2 having this shape is subjected to anodic oxidation treatment to form an oxide 4. By adopting such a shape, the adhesion between the piezoelectric ceramic 1 and the electrode 2 is improved, and the strength of the laminate is improved. Moreover, unlike the conventional example, it does not require a thick insulator, so it is suitable for reducing the thickness of piezoelectric ceramics.

Next, another method of manufacturing a laminated piezoelectric element will be explained using FIG. a) shaped and bonded piezoelectric ceramics] and aluminum alloy molds 442a that are different from +h every other layer,
After stacking layers 2b alternately, heat to 600°C under pressure of 0.2 to 1 kg/rm12 in an argon atmosphere using a blower and hold for 1 hour to form a laminate. After polishing, a "positive electrode 3' was formed on only the wide area of the electrode 2a or the exposed side surface. b) Electrode 73
′ was anodized. Then, the end surface of the electrode 2a that is in contact with the electrode 3' changes to an oxide 4a. In the figure, the oxide 4 is shown to be protruding to emphasize that the opposite surface of the electrode 3' is also changed into an oxide, but in reality it becomes a smooth blood. c) The laminate was cut so that the J-shaped rods 2a and 2b had the same area and had a full-surface electrode structure. d
) Even more talented? Lead terminals a and b were then formed on the electrode 2a which had been subjected to the oxidation treatment, and brought into electrical contact with the electrode 2b. 0) Electrode X3)) was anodized. Then, contact with electrode 3b /'I! The end surface of the electrode 2b, which is oxide 4b, changes to oxide 4b.

f) Lead terminals 3a were formed on the side surfaces where metal [nJ was exposed, f'll electrodes 2a and oxides 4] were alternately present, and brought into electrical contact with the electrodes 2a. The rest is the same as in the multiplex embodiment. This method is suitable for manufacturing a laminated piezoelectric element that uses electrodes with a relatively wide area and does not require cutting the laminated body.

In each of the above embodiments, measures may be taken such as improving the water permeability of the resin for molding 1~ covering the outermost layer of the piezoelectric element to prevent water from entering, or completely covering the piezoelectric element with a metal cover. The resin for molding is epoxy resin (used in the molding of most semiconductor devices), or phenol novolak resin as a curing accelerator, silicone rubber as a flexibility imparting agent, or strength.
No, a mixture of silica and alumina powder as a filler for a slimy tank. Other examples include Boliimi 1-resin and fluororesin.

In addition, activated gold ρt becomes chemically stable through oxidation and nitridation.
In addition to AQ, , AQ, alloys, Ni, and Ni-based alloys, S
n (tin) + Sn-based alloy, ]n (indium), ■n
-L'i (titanium), 'J' j-based alloy.

Zr (Silconium) + L r-based alloy, Cu (Copper).

Cu-based alloy, Fe (iron), Fe-based alloy, Zn(ll
Examples include lead), Zn-based alloys, etc.

FIG. 9 is a longitudinal sectional view showing an example of the structure of a mass flow controller 1 roller using the laminated piezoelectric element of the present invention. 9th
In the figure, the piezoelectric element "-4 is expanded and contracted by applying a voltage, and the movement is transmitted to the tire flat t112, and the opening of the orifice 13 installed in the flow path of the fluid (for example, waste) to be controlled is controlled y1' Control the meteor by pressing the button.

This kind of mass flow controller has dramatically better responsiveness to the setting of the gill than that using a conventional solenoid1, and also has a shorter service life, which is a problem when using a pressure element with a conventional structure. Improved shortness and quiet operation voltage.

FIG. 10 is a longitudinal sectional view showing an example of the structure of an injection valve (fuel injection valve) using the laminated piezoelectric element of the present invention. In Figure L0, the piezoelectric element 21 is expanded and contracted by applying a voltage, and the movement is transmitted to the cylinder 22, thereby establishing a connection between the flow passages 2 and 3 on the fuel inlet side and the flow passage 24 provided in the cylinder. conduct. In that case, the amount of fuel to be injected is controlled by adjusting the passage time to the pressure element.

Such an injection valve eliminates problems such as the need for a step-up transformer for the voltage application phase and the deterioration of life due to adhesion of fuel mist, which occur when piezoelectric elements of conventional structure are used. In addition, the advantages of using piezoelectric elements, such as improved responsiveness and accuracy of fuel injection, can be utilized to the fullest.

FIG. 11 is a side view showing an example of the structure of a movement stage for precision positioning using the laminated pressure displacement element of the present invention. In FIG. 11, the stage 34 is a coarse movement stage that is moved by a linear actuator such as a pole screw. Then, the fine movement stage 32 installed at -1- is moved by the piezoelectric element r-31.

(z6) By using the piezoelectric element of the present invention in such a moving stage, a piezoelectric element-applied rod has better positioning responsiveness and accuracy than conventional ones! l! The moisture resistance and reliability of the stage can be improved, and a moving stage that can operate with excellent reliability even in a humid environment can be constructed.

FIG. 2 is a side view showing an example of the structure of a printing spatula 1 of a printer using the laminated piezoelectric element of the present invention. 1st
In Figure 2, the displacement generated by the piezoelectric element 41 is caused by the leaf spring 4.
It is transmitted to the printing pin 43 through the lever No. 2, and printing is performed.

These printheads are not only highly responsive;
It has the advantage of having a very compact structure and strong printing power, and also exhibits high performance that maintains sufficient reliability even in humid environments.

〔Effect of the invention〕

According to the present invention, the moisture resistance of the laminated piezoelectric element can be improved, and the operating voltage of all 1 m'' rod type elements can be lowered and reliability can be improved.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a laminated piezoelectric element according to an embodiment of the present invention before being coated with molding resin, FIG. 2 is a cross-sectional view thereof, and FIG. A perspective view showing the structure, FIG. 4 is a schematic diagram illustrating the manufacturing process of a laminated piezoelectric cable according to an embodiment of the present invention, and FIG. 5 is a sectional view showing one shape of the end surface of the electrode. FIG. 6 shows the product J of another embodiment of the present invention.
? Flow schematic diagram showing the manufacturing process of an 11-type piezoelectric element, No. 7
The figure shows a conventional example of a full-surface electrode type laminated pressure sensor. 8 is a sectional view taken along the line A-A in FIG. 7, FIG. 9 is a vertical sectional view of a mass flow controller according to an application example, and FIG. 1.0 is an incision diagram according to an application example. FIG. 11 is a vertical cross-sectional view of a valve; FIG. 11 is a vertical cross-sectional view of a movement stage for precision positioning according to an application example; FIG. 12 is a vertical cross-sectional view of a print head of a printer according to an application example. 1... Piezoelectric ceramic plate, 2... Electrode plate, :3...
Lee 1-terminal, 4...electrical insulating compound, 5...resin for molding 1-.

Claims (14)

[Claims] 1. A pair of external lead terminals is attached to the side surface of a laminate of a plurality of piezoelectric ceramic plates and a metal plate interposed between the piezoelectric ceramic plates, and the metal plate is made of aluminum, aluminum alloy, nickel, or nickel. In a laminated piezoelectric element that is a flat plate with a single layer or multiple layers selected from a series of alloys, the metal plates are alternately brought into electrical contact with one of the lead terminals, and the other lead terminal and the metal plate are alternately brought into electrical contact with one of the lead terminals. is electrically non-contact, and the non-contact end portion is an electrically insulating compound substitute for the metal plate. 2. A pair of external lead terminals is attached to the side surface of a laminate of a plurality of piezoelectric ceramic plates and a metal plate interposed between the piezoelectric ceramic plates, and the metal plate is chemically oxidized and/or nitrided. In a laminated piezoelectric element that is a single-layer or multi-layer flat plate made of a stable active metal or an alloy mainly composed of the active metal, the metal plate is alternately brought into electrical contact with only one of the lead terminals. , and the other lead terminal and the metal plate are not electrically in contact with each other, and the non-contact end portion is an electrically insulating compound substitute for the metal plate. 3. In a laminated piezoelectric element, a pair of lead terminals for external extraction is attached to the side surface of a laminate of a plurality of piezoelectric ceramic plates and a metal plate interposed between the piezoelectric ceramic plates, wherein the metal plates are alternately connected to the leads. One of the terminals is electrically contacted, and the other lead terminal and the metal plate are not in electrical contact, and the non-contact portion is made of oxide and/or nitride of the metal plate material. A multilayer piezoelectric element characterized by: 4. 3. The multilayer piezoelectric element according to claim 1, wherein the electrically insulating compound is selected from anodic aluminum oxide, anodized nickel, plasma discharge aluminum nitride, and plasma discharge nickel nitride. 5. 5. The laminated piezoelectric element according to claim 1, wherein a side surface of the laminated body is coated with a molding resin. 6. 6. The laminated piezoelectric element according to claim 1, wherein the piezoelectric ceramic plate and the metal plate have substantially the same planar dimensions. 7. 7. The laminated piezoelectric element according to claim 1, wherein the alloy applied to the metal plate is aluminum in which one or a mixture of silicon, magnesium, and germanium is dissolved as a solid solution. 8. The alloy applied to the metal plate is nickel, chromium,
The laminated piezoelectric element according to any one of claims 1 to 7, characterized in that it contains palladium, copper, or a mixture thereof as a solid solution. 9. 9. The laminated piezoelectric element according to claim 1, further comprising a heater provided outside the laminated body. 10. 10. The laminated piezoelectric element according to claim 1, wherein the electrically insulating compound substitutes are alternately positioned on each metal plate. 11. In a mass flow controller comprising a flow channel throttling adjustment mechanism in the middle of a flow path through which a fluid flows, the adjustment mechanism includes a diaphragm facing the flow path and a piezoelectric element connected to the diaphragm, and the piezoelectric element Claim 1
A mass flow controller comprising any one of 1 to 10. 12. In an injection valve in which a fuel flow path that moves with the movement of a cylinder and a fuel flow path formed in an outer cylinder in which the cylinder is housed are connected and disconnected by the movement of the cylinder, the above-mentioned claim is provided as a driving means for the cylinder. An injection valve characterized by using the laminated piezoelectric element according to any one of Items 1 to 10. 13. A laminated piezoelectric element characterized in that a laminated body is formed by laminating a plurality of piezoelectric ceramic plates with metal plates interposed between them, and then a pair of lead terminals for external extraction are attached to the side surfaces of the laminated body. In the manufacturing method, after the metal plates are laminated between piezoelectric ceramic plates, the ends of the metal plates are anodized and cut every other layer, and the anodized parts and the untreated ends of the metal plates are directly covered. A method for manufacturing a multilayer piezoelectric element, which comprises forming one lead terminal, and then anodizing the other end surface of an untreated metal plate end to form the remaining lead terminals. 14. 14. The method for manufacturing a laminated piezoelectric element according to claim 13, wherein the control includes performing plasma discharge nitriding treatment in place of the anodizing treatment.