JPS63155684A - Lamination type piezoelectric body and manufacture thereof - Google Patents

Abstract

PURPOSE:To increase junction areas connecting between metallic protrusions and a side leas wire and combine them without causing defective junction by performing a lapping at each tip of the metallic protrusions, thereby arranging so that tips of the metallic protrusions may lie on the same plane. CONSTITUTION:After forming metallic protrusions 3 processed by Ni plating at end edges of internal electrodes 200 of a laminate body 100, a lapping processing is carried out at uneven tips of the metallic protrusions and a flat plane is formed at the tip parts after making tip parts of uniform height. Subsequently, thin solder is applied to the metallic protrusions 3 as well as to the surface of the side lead wire 4 and its lead wire 4 is placed on a line of the metallic protrusions that are composed of the metallic protrusions 3 and is pressed by heating with a metal pressure attachment member. Further, the end parts of the side lead wire 4 are fixed to metallic pieces 6 that are bonded to a dummy plate 5 with soldering means and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laminated piezoelectric material and a method for manufacturing the same, which is formed by laminating a large number of plate-like members made of piezoelectric elements.
The present invention relates to a laminated piezoelectric material that expands and contracts in response to applied voltage and acts as an actuator, and a method for manufacturing the same.

[Technical background]

The inventors of the present application previously provided a laminated piezoelectric material as shown in FIG. 8 in Japanese Patent Application No. 61-200111.

In the laminated piezoelectric body shown in FIG. 8, a plurality of piezoelectric plates 80
2 are laminated, and the piezoelectric plates 802 are fixed and integrated with an internal electrode 800 disposed between them to form a laminate.

Then, in the axial direction of the outer periphery of this laminate, every other internal electrode 800 is electrolessly plated to form a row of metal protrusions 8030. A side lead wire 804 is connected to the row of metal protrusions formed on this internal electrode, and a voltage from an external power source is applied from the side lead wire 804 to each piezoelectric plate 802 via the metal protrusion 803 .

[Problem that the invention seeks to solve]

However, in a laminated piezoelectric material as shown in FIG.
It is difficult to form all the metal protrusions 803 formed on the outer circumferential side of the laminate with the same protrusion amount. Therefore, when connecting the side lead wire 804 to the metal protrusion 803, if there is a metal protrusion with a small amount of protrusion, such as the metal protrusion 803a, there is a problem that the side lead wire 804 is not properly connected.

Therefore, the side lead wire 804 and the metal protrusion 80
3a, there is a problem that not only is voltage not supplied to the piezoelectric plate 802, but also that the bonding strength between the side lead wire 804 and the metal protrusion 803 is reduced.

In addition, in this laminated piezoelectric body, the side lead wire 804 and
An external lead wire connecting to an external power source is directly connected to the side lead 804 by means such as soldering. Therefore,
If an external force is applied to this external lead wire, there is also a concern that the external force will be directly transmitted to the side lead wire 804 and the connection between the side lead wire 804 and the metal protrusion 803 will be disconnected. Moreover, there is also a concern that the connection between the external lead wire and the side lead wire 804 may come off at the same time.

In addition, in such a laminated piezoelectric body, since the tip of the metal protrusion 803 is rounded, the metal protrusion 803
The joint area between the side lead wire 804 and the side lead wire 804 is extremely small. Therefore, there is a problem in that sufficient bonding strength between the metal protrusion 803 and the side lead wire 804 cannot be ensured.

[Means for solving problems]

The present invention aims to solve the above-mentioned problems, and the following measures have been taken to solve the problems. In other words, there is a laminate in which a plurality of piezoelectric plates are laminated, and the piezoelectric plates are fixed and integrated with internal electrodes arranged between them, and a line is formed in the axial direction of the outer periphery of this laminate in every other internal electrode. a first metal protrusion row formed with metal protrusions, the tips of which are ramp-processed so that the tips of the metal protrusions are located substantially on the same plane; and the first metal protrusion row. A row of metal protrusions are formed on the internal electrode on which the first row of metal protrusions is not formed, spaced apart in the outer circumferential direction of the laminate, and tips of the metal protrusions are located on substantially the same plane. a second row of metal protrusions whose tips are lamp-processed, dummy plates arranged at the upper and lower ends of the laminate, the first row of metal protrusions, and the second row of metal protrusions. a conductive metal piece that is fixed to the dummy plate and to which the end of the side lead wire is electrically connected and fixed; and the conductive metal piece. an external IS wire that is electrically connected and fixed to the external power source and electrically connects the conductive metal piece to the external power source; The laminated piezoelectric body was provided with an insulating coating layer formed between each row of metal protrusions and insulating internal electrodes existing between each row of metal protrusions.

Further, a first metal protrusion row is formed by stacking a plurality of piezoelectric plates with internal electrodes interposed therebetween, and forming metal protrusions projecting outward from the piezoelectric plates on every other internal electrode. and forming metal protrusions projecting outward from the piezoelectric plate on every other internal electrode on which the first metal protrusion array is not formed, spaced apart from the first metal protrusion array in the outer circumferential direction. forming a second row of metal protrusions by lapping the tips of the first and second rows of metal protrusions to form substantially the same plane; A solder layer is formed on the first and second metal protrusions on which the solder layer is formed, and a side lead wire coated with solder is brought into contact with each of the first and second metal protrusions on which the solder layer is formed. A method of manufacturing a laminated piezoelectric body is provided in which the side lead wires are fixed to the first and second metal protrusion rows by pressing, and the external lead wires are connected to the side lead wires.

[Operation and effect of the invention]

In the present invention, the tips of the metal protrusions are lapped so that the tips are located on substantially the same plane, so the bonding area with the side lead wires is increased, and the row of metal protrusions and side leads The wires can be well connected to each other without causing bonding defects.

In addition, the side lead wires and the external lead wires are not directly connected to each other, but are each connected to a metal piece, so even if an external force is applied to the external lead wires, that force will be applied directly to the side lead wires. It has no effect on the line. Therefore, there is no problem that the joint between the side lead wire and the metal protrusion separates due to this external force.

Furthermore, since the side lead wires are connected and fixed to each row of metal protrusions at once, the workability is very good.

〔Example〕

FIG. 1 is a perspective view showing an embodiment of the present invention.

In FIG. 1, 2 is a piezoelectric plate, 200 is an internal electrode that fixes and integrates the piezoelectric plate 2, and 3 is a plated plate on every other internal electrode 200 on one side of the laminate 100 consisting of the piezoelectric plate 2 and the internal electrodes 200. 3 is a side lead wire connected to a first row of metal protrusions made up of the plurality of metal protrusions 3; 5 is a dummy plate disposed at the upper and lower ends of the laminate 100;
6 is a conductive metal piece fixed to this dummy plate 5 and to which the end of the side lead wire 4 is electrically connected, and 7 is an external lead wire electrically connected to this metal piece 6.

FIG. 2 is a diagram showing a state in which three piezoelectric plates 2 are taken out of a plurality of stacked piezoelectric plates 2 and transferred to each other. This piezoelectric plate 2 is made by firing a molded ceramic sheet such as PZT, polishing the outer periphery, and lapping the surface. An electrode paste is screen printed on the surface to form internal electrodes 20.
0 is the formation. At this time, the piezoelectric plate 2 is formed by cutting the opposing circumferential surfaces of a disc (about 15 mm in diameter) parallel to each other, as shown in the figure, to form side surfaces for drawing out the protruding electrodes. Further, the internal electrodes 200 are formed using two types of electrical pastes, and one pattern 201 is formed using silver paste and palladium (or Fe, Co, or Ni).

Group II metals such as Ru, Os, Ir, Pt, etc.) from 5 to
Another pattern 2 of the paste mixed with 30wt%
02 is lead (or Sb) in silver paste.

A paste containing 5 to 30 wt% of Sn, Zn, etc.) is used. Of the outer periphery of the piezoelectric plate l, the pattern 201 contacts only the end surface for leading out the external electrode (one of the side surfaces cut parallel to the circumferential surface of the disk), and the pattern 12 contacts the remaining outer periphery. ing.

This piezoelectric plate 2 is dried at 100° C., and a predetermined number of sheets are stacked so that the pattern 201 is placed at the same position on every other sheet as shown in FIGS. 2 and 3. And the laminate 100
The paste is baked by increasing the temperature to 600°C in an oxygen atmosphere while applying a load of about 1 kg/crfl to the paste.

At this time, the piezoelectric plate 2 is fixed and integrated by the glass contained in the electrode paste.

The integrated laminate 100 is subjected to electroless polishing as follows. The first method is to perform alkaline degreasing with an alkaline degreasing solution (manufactured by Henkel Hakusuisha), wash with water, soak in hydrochloric acid (1:1 ratio) for 1 to 2 minutes, wash with water, and heat at approximately 80°C.
Soak in sodium hypophosphite for about 10 minutes. Then, the metal projections 3 and 9 are immersed in electroless plating solution 8780 (manufactured by Nippon Kanigen Co., Ltd.) at about 90° C. until the height of the metal protrusions 3 and 9 reaches 50 to 100 micrometers.

The second method is to first mask the areas you do not want electroless plating with Teflon tape or the like, and then expose only the areas you want to plate. Then, perform alkaline degreasing with an alkaline degreasing solution (manufactured by Henkel Hakusuisha) and wash with water. Then, soak it in hydrochloric acid (1:1) for 1 to 2 minutes, wash it with water, and hold it at about 60°C.
Soak in active solution N003 (manufactured by Nippon Kanigen Co., Ltd.) for 10 minutes and wash with water.

Then, it was immersed in 5B155 electroless plating solution (Japanese (manufactured by Kanigen Co., Ltd.) for about 10 minutes, and then washed with water. Then, the metal protrusion 9 is immersed in a 3780 electroless plating solution at about 90"C until the height of the metal protrusion 9 reaches 50 to 100 microns. When the plating is completed, the mask is removed.

When plating is performed, as shown in FIGS. 1 and 3, every other internal electrode 20 is formed on each opposing surface of the laminate 100.
A metal protrusion 3.9 made of nickel plating is formed on the edge of 0. In this electroless plating, pattern 201
The area marked with pattern 20.2 is activated by palladium, so the plating adheres well, but the area of pattern 20.2 is difficult to adhere to because lead acts as a catalyst poison, so metal protrusions as shown in Figures 1 and 3 are used. 3 and 9 are formed.

Since the heights of the metal protrusions 3.9 formed in this way are uneven as shown in FIG. The flat parts 301 and 901 are formed at the tips thereof. After lapping the metal protrusions 3 and 9 to form the flat parts 301 and 901 in this way, they are washed with water,
After drying, the side lead wires 4 are attached. Attachment of this side electrode is performed in the following manner.

First, the piezoelectric body 100 with projections formed as described above is immersed in flux and passed through a solder layer whose temperature is controlled to 250° C., thereby applying a thin layer of solder to the metal projections 3°9.

Further, the side lead wire 4 is made into a flat plate shape as shown in FIG. 4(b) by applying pressure from the top and bottom of the round bar 401 as shown in FIG. 4(a). .

Then, as shown in FIG. 4(b), the flat side lead wire 4 is dipped in flux and passed through a solder layer to apply a thin layer of solder to the surface of the side lead wire. Then, a first
By placing the side lead wires on the first row of metal protrusions and the second row of metal protrusions, and thermocompressing them with a metal pressure bonding member heated to 250°C, the solder adhering to the surfaces of both melts. A side lead wire 401 is fixed onto the metal protrusion row.

In this way, the laminate 1 to which the side lead wires 4 are connected
Dummy plates 5 having the same outer circumferential shape as the piezoelectric plate 2 and a slightly thicker thickness are arranged at the upper and lower ends of the piezoelectric plate 2 in the stacking direction. A bottomed hole 501 with a diameter of about 1 mm is bored in the side notch of this dummy plate 5.

The metal piece 6 is a strip-shaped piece made of conductive metal, and a metal pin 8 having an outer diameter of about 1 mm is spot welded to the metal plate 6 (FIG. 6).

A metal pin 8 is spot-welded to this metal piece 6.
is inserted into the hole 501 made in the above-mentioned dummy plate 5, and both are fixed with adhesive.

To the metal piece 6 fixed to the dummy plate 5 in this way,
The ends of the above-described side lead wires 4 are fixed to the two series of side surface leads 1' wires 6 by means such as soldering. After the metal piece 6 is fixed to the dummy plate 5 in this way, this laminate 100
is placed in a mold coated with a release agent. Then, adhesive epoxy resin, silicone, fluorosilicone, or the like is poured into the gap formed between the inner surface of the mold and the outer peripheral surface of the laminate 100 to form an insulating coating layer on the outer peripheral surface of the laminate 100. This insulating coating layer is formed between the metal protrusions of the first metal protrusion row made up of metal protrusions 3 and the second metal protrusion row made up of metal protrusions 9, and covers the internal electrodes present between each metal protrusion row. Insulated.

Although the side lead wire 4 shown in FIG. 1 has a straight flat plate shape, it may have a meandering shape as shown in FIG. (
As shown in b), the side lead wire may have a spiral shape.

Further, in the above example, the metal piece 6 was made into a rectangular strip, but as shown in FIG. It's okay. In this case, as shown in FIG. 7, a connecting pin 8 is spot welded to one edge 6a of the substantially doglegged metal piece 6, thereby fixing it to the dummy plate 5. Also, this -
The side lead wire 4 is fixed to the blade piece 6a by means such as soldering. On the other hand, a side lead wire 7 is electrically connected and fixed to the other piece 6b of the metal piece 6 by means such as soldering. By forming the metal piece 6 in such a shape, the metal piece 6 can also have elasticity. Therefore, even if an external force acts on the external lead wire 7, this external force can be absorbed by the elastic deformation of the metal piece 6.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a laminated piezoelectric body, Figure 2 is a perspective view of a single piezoelectric plate, Figure 3 is a front view of the laminated piezoelectric body, and Figure 4 is a perspective view showing the forming process of side lead wires. , FIG. 5 is a schematic diagram showing side lead wires, FIGS. 6 and 7 are partial perspective views of a laminated piezoelectric body, and FIG. 8 is a front view of a conventional laminated piezoelectric body. 2... Piezoelectric plate, 3... Metal protrusion, 4... Side lead wire. 5...Dummy plate, 6...Metal piece, 7...External lead wire.

Claims (2)

[Claims] (1) A laminate in which a plurality of piezoelectric plates are laminated, and the piezoelectric plates are fixed and integrated with internal electrodes placed between them, and in the axial direction of the outer periphery of this laminate, a line is aligned with every other internal electrode. a first metal protrusion row formed with metal protrusions, the tips of which are lapped so that the tips of the metal protrusions are located substantially on the same plane; A row of metal protrusions is formed on the internal electrode on which the first row of metal protrusions is not formed, spaced apart from each other in the outer circumferential direction of the laminate, and the tips of the metal protrusions are arranged on substantially the same plane. a second row of metal protrusions whose tips are lapped so that they are in position; dummy plates arranged at the upper and lower ends of the laminate; the first row of metal protrusions and the second metal protrusions; a side lead wire electrically connected to each protrusion of the row; a conductive metal piece fixed to the dummy plate and to which an end of the side lead wire is electrically connected; and the conductive metal piece. an external lead wire that is electrically connected and fixed to the conductive metal piece and electrically connects an external power source to the conductive metal piece; A laminated piezoelectric body comprising an insulating coating layer formed between metal protrusions and insulating internal electrodes existing between each row of metal protrusions. (2) A first row of metal protrusions is formed by stacking a plurality of piezoelectric plates with internal electrodes interposed therebetween, and forming metal protrusions projecting outward from the piezoelectric plates on every other internal electrode. and forming metal protrusions projecting outward from the piezoelectric plate on every other internal electrode on which the first metal protrusion array is not formed, spaced apart from the first metal protrusion row in the outer circumferential direction. forming a second row of metal protrusions by lapping the tips of the first and second rows of metal protrusions to form substantially the same plane; A solder layer is formed on the surface, a side lead wire coated with solder is brought into contact with each of the first and second metal protrusions on which this solder layer is formed, and the heated crimping jig is connected to the side lead wire. A method of manufacturing a laminated piezoelectric body, comprising: fixing a side lead wire to the first and second rows of metal protrusions by pressing the wire; and connecting an external lead wire to the side lead wire.