JPH06105800B2 - Electrostrictive effect element - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostrictive effect element, and more specifically, to an electrode structure of a laminated electrostrictive effect element utilizing a vertical effect.

Conventional technology Electrostrictive effect elements that convert vibrations and external forces into electrical signals
Currently, it is used in various fields familiar to us, such as audio products and piezoelectric switches.

Such an electrostrictive effect element has an internal structure in which a plurality of electrostrictive material layers 1 and internal electrode layers 2 are located at upper and lower ends as shown in a perspective view of FIG. 2A and a sectional view of FIG. The electrode layers 2a and 2b are alternately laminated to form a laminated body. The electrostrictive material layer 1 is made of a ceramic such as lead zirconate titanate having a composite perovskite structure, and the internal electrode layer 2 is made of a silver-palladium alloy.

Further, protective layers 3a and 3b made of an electrostrictive material are disposed in contact with the internal electrode layers 2a and 2b at the upper and lower ends.

Further, on the side wall surface of the electrostrictive effect element shown in the drawing, the end surface of the internal electrode layer 2 is covered and insulated by every other layers by the insulating substances 4a and 4b, as shown in FIG. 2 (b). The coating is provided on both side walls of the electrostrictive effect element so as to be staggered layer by layer. An external electrode layer 5a for electrically connecting every other internal electrode layer 2 of the electrostrictive effect element is provided on the coating of the insulating materials 4a and 4b.
And 5b are attached and arranged. Furthermore, each of the external electrode layers 5a and 5b, and the end face electrode layers 6a and 6b disposed on the upper and lower surfaces of the protective layers 3a and 3b made of the electrostrictive material are at corners of the protective layers 3a and 3b, respectively. It is electrically connected by depositing a conductive material.

Therefore, charges are applied to each internal electrode layer 2 of the electrostrictive effect element layer by layer.

Normally, such an electrostrictive effect element is attached by attaching the mounting members 7 and 8 of the electrostrictive effect element to the end surface electrodes 6a and 6b by soldering, and applying a predetermined voltage between the mounting members 7 and 8 causes the external surface of the end surface to be removed. When the voltage is applied to all the internal electrode layers 2 through the electrode layers 5a and 5b, the entire element is distorted in the X and Y directions indicated by the arrows in the figure due to the vertical effect.

Problems to be Solved by the Invention However, the conventional electrostrictive effect element as described above requires the step of depositing the end face electrode layers 6a and 6b in addition to the step of depositing the external electrode layers 5a and 5b. However, there is a drawback that the manufacturing cost becomes high.

Further, the external electrode layers 5a and 5b and the end face electrode layers 6a and 6b are electrically connected by overlapping the electrode layers by printing at the corners of the protective layers 3a and 3b, but if a large amount is attached, the end face electrode layers are formed. There is also a problem in that the flat state becomes worse and the mounting member tilts as shown by reference numeral A in FIG. 2 (b), and the desired distortion effect cannot be obtained.

In addition, if the amount of the electrode layer adhered by printing is small, the electrical reliability of the connection portion is reduced.

Therefore, the present invention is intended to solve the above problems, to reduce the manufacturing cost of the electrostrictive effect element, and to provide an electrostrictive effect element having a stable structure that can obtain good effects. .

Means for Solving the Problems That is, according to the present invention, a plurality of electrostrictive material layers and internal electrode layers are alternately laminated so that the upper and lower ends are internal electrode layers, and the upper and lower ends are positioned. And a protective layer disposed so as to be in contact with the internal electrode layer, and an insulating material is applied to the exposed portion of the internal electrode layer on one side surface of the laminated body every other layer from above. Of the first external electrode layer extended to the wall surface of the protective layer and the exposed portion of the internal electrode layer on the other side surface of the laminate where the insulating substance is not applied, from above. In the electrostrictive effect element including a second external electrode layer extended to the wall surface of the other protective layer, the electrostrictive effect element is connected to the first and second external electrode layers on the side wall surface of the protective layer. , Conductive metal caps on top and bottom of the stack, respectively Is further provided.

Action As described above, the external electrode layers arranged on the side walls of the electrostrictive effect element are connected to the conductive metal caps capped on the upper and lower ends of the laminate and the side wall surfaces of the protective layer, respectively. ,
At the time of manufacturing the electrostrictive effect element, a manufacturing process for disposing the end face electrode layer is not required, which not only reduces the manufacturing cost but also stabilizes the mounting member of the electrostrictive effect element on the upper and lower end surfaces. It can be arranged in a good condition.

EXAMPLES Next, examples of the electrostrictive effect element according to the present invention will be described with reference to the drawings.

FIG. 1 (a) is a perspective view of an embodiment of the electrostrictive effect element of the present invention, and FIG. 1 (b) is a sectional view of FIG. 1 (a).

An embodiment of the electrostrictive effect element according to the present invention is a conductive metal cap capped on the upper and lower parts of the electrostrictive effect laminate.
Other structures except that one ends of the external electrode layers 5a and 5b are connected to 9a and 9b are the same as the structure of the conventional electrostrictive effect element shown in FIG. The same reference numerals are given and the description thereof is omitted.

As a method of manufacturing such an electrostrictive effect element, first, a calcined powder of a ceramic made of lead titanate or the like is prepared, and a small amount of an organic binder such as polybutyral resin and a plasticizer such as dioctyl phthalate are mixed with ethyl cellosolve or the like. Disperse in organic solvent to make sludge. This sludge is fluid-coated on a polyester film having a thickness of 100 μm by a slip casting method using a doctor blade and adhered in the form of a green sheet having a thickness of 70 μm to form an electrostrictive material layer 1. Next, a conductor paste such as a silver-palladium paste is applied onto the green sheet by screen printing to form the internal electrode layer 2. Then, the green sheet in the portion where the internal electrode layer 2 is printed is cut into a predetermined size and peeled from the polyester film. A desired number of the green sheets are stacked and pressure-bonded from above and below by a hot press to form a laminated body in which the electrostrictive material layers 1 and the internal electrode layers 2 are alternately arranged. In addition, in the step of stacking the green sheets, 20 to 30 green sheets on which the internal electrode layers are not formed are stacked on the upper and lower surfaces of the internal electrode layers 2 at the upper and lower ends, respectively, to form an insulating protective layer as a dummy layer.
9a and 9b are formed.

Next, the organic binder contained in this laminate is decomposed at a high temperature to be evaporated and removed, and then the temperature is raised to 1120 ° C. at a rising speed of 5 ° C./min. Make a conclusion. Next, the laminated body after sintering is cut into a lattice shape to obtain a laminated body in which the end faces of the internal electrode layers 2 are exposed. An insulating substance 4a such as glass is deposited on the end faces of the internal electrode layers 2 on every one side face of the laminate by electrophoresis, and the other side face is not coated with the insulating substance 4a. The insulating material 4b is applied to the opposite end surface of the internal electrode layer 2. A conductive paste such as a silver paste is screen-printed on each of the upper surfaces of the insulating materials 4a and 4b by screen printing in order to electrically connect the internal electrode layers 2 not covered with the insulating material. 9a or
The first external electrode layer 5a and the second external electrode layer 5b are formed by extending and printing on the wall surface of 9b.

Next, a conductive metal cap such as brass having a depth of about half the height of the protective layers 3a and 3b is formed on the upper and lower portions of the laminated body.
9a, 9b is press-fitted, the ends of the metal caps 9a and 9b,
This can be completed by electrically connecting the external electrode layers 5a and 5b to the wall surfaces of the protective layers 3a and 3b by soldering or the like.

EFFECTS OF THE INVENTION As described above, according to the present invention, the step of depositing the end face electrode layer is unnecessary, and the manufacturing cost can be reduced. Further, the electrostrictive effect element can be vertically and stably attached to the attaching member, and a desired longitudinal effect strain can be obtained. Furthermore,
The reliability of the connection between the conductive metal cap and the external electrode layer is secured, and the quality of the electrostrictive effect element is significantly improved.

The electrode structure of the electrostrictive effect element according to the present invention is not limited to a rectangular cross section in the stacking direction, and may be used in a circular or polygonal cross section.

[Brief description of drawings]

1 (a) and 1 (b) are a perspective view of an electrostrictive effect element of the present invention and a longitudinal sectional view thereof, and FIGS. 2 (a) and 2 (b) are perspective views of a conventional electrostrictive effect element. It is a figure and the sectional view of the longitudinal direction. (Main reference numbers) 1 ... Electrostrictive material layer, 2 ... Internal electrode layer, 3a, 3b ... Protective layer, 4a, 4b ... Insulating material, 5a, 5b ... External electrode layer, 6
a, 6b ... End surface electrode layer, 7,8 ... Mounting member, 9a, 9
b …… Metal cap

Claims (1)

[Claims] 1. A plurality of electrostrictive material layers and internal electrode layers are alternately laminated so that the upper and lower ends are internal electrode layers, and the electrostrictive material layers and the internal electrode layers are arranged in contact with the internal electrode layers located at the upper and lower ends. A laminate formed by a protective layer, and 1 of the laminate.
A first external electrode layer, which is formed by applying an insulating material every other layer on the exposed portion of the internal electrode layer on the side surface and extending from the wall surface of one protective layer to the insulating material on the other side surface of the laminate. In the electrostrictive effect element, the second external electrode layer is formed by applying an insulating substance to the exposed portion of the internal electrode layer not coated with the conductive substance and extending the second external electrode layer on the wall surface of the other protective layer. An electrostrictive device further comprising conductive metal caps capped on the upper and lower portions of the laminate so as to be connected to the first and second external electrode layers on the sidewall surface of the protective layer. Effect element.