JPH03136384A - Electrostrictive effect element - Google Patents

Abstract

PURPOSE:To enhance insulating resistance of glass and an outer electrode layer and to largely improve reliability of an electrostrictive effect element by providing a frame type second insulating layer having a larger outer shape than the outer layer and a smaller inner shape than the outer layer between a glass insulating layer and the outer layer. CONSTITUTION:A masking material such as a Teflon tape or the like is adhered to the surface opposed to a surface formed with a glass insulating layer 3, and the layers 3 are formed at every other layer on an inner electrode layer 2 exposed on the front surface of a block 9 by an electrophoresis method by using temporary electrode layers formed on the both right and left faces of the block 9. Then, the masking material is adhered to the surface formed with the layer 3 in a previous step, and the layers 3 are formed at every other layer on the layer 2 exposed on the front face of the block 9 by the same electrophoresis method as in the previous step. Then, it is so formed as to be superposed on a second insulating layer 5. Thereafter, the block is so cut on a chip that an outer electrode layer 4 corresponds to one chip by a cutter using metal, for example, a wire such as a piano wire, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostrictive element in which electrostrictive material layers and internal electrode layers are alternately laminated, and particularly relates to the formation of external electrode layers.

[Conventional technology]

Conventionally, a stacked type electrostrictive element has the following structure, as shown in Fig. 10.
Sheet-shaped electrostrictive material layers 1 and internal electrode layers 2 are alternately laminated, and one end of the internal electrode layer 2 exposed on a pair of opposing side surfaces is insulated differently from each other on the pair of side surfaces by glass. The other internal electrode layer 2 that is not connected is connected to the external electrode layer 4 provided on each side. At this time, the glass and the external electrode layer 4 are in direct contact.

[Problem to be solved by the invention]

The structure of the conventional electrostrictive effect element described above has the following problems: - The insulation resistance decreases significantly between the outer periphery of the external electrode layer and the internal electrode layer, which is insulated by glass, impairing the reliability of the electrostrictive effect element. There are drawbacks.

An object of the present invention is to provide an electrostrictive effect element that can increase the insulation resistance between the glass that insulates the ends of the internal electrodes and the external electrode layer, and has significantly improved reliability.

[Means to solve the problem]

In the electrostrictive effect element of the present invention, a plurality of electrostrictive material layers and an internal electrode layer are alternately exposed on opposing sides of a laminate, and a first layer is alternately placed on an exposed portion of one of the opposing sides of the stack. In an electrostrictive effect element in which a glass insulating layer is formed as an insulating layer, and external electrode layers are formed on opposing sides to electrically connect the exposed portions of the internal electrode layers where the glass insulating layer is not formed, The structure is characterized in that a frame-shaped second insulating layer is provided between the glass insulating layer and the external electrode layer, the outer shape of which is larger than that of the outer electrode layer, and the inner shape of which is smaller than that of the external electrode layer.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIGS. 1(a) and 1(b) are a front view and a sectional view of an electrostrictive effect element according to an embodiment of the present invention. In the figure, 1 is a ceramic electrostrictive material layer made of lead zirconate titanate having a composite perovskite structure, 2 is an internal electrode layer using a silver-palladium alloy disposed to sandwich the electrostrictive material layer 1, and 3 4 is a glass insulating layer coated to insulate every other end face of the internal electrode layer 2, and 4 is an external glass insulating layer coated with conductive paste to electrically connect every other internal electrode layer 2. The electrode layer 5 is a second insulating layer made of resin or the like disposed between the glass insulating layer 3 and the external electrode layer 4. FIG. 2 is a perspective view of another embodiment of the present invention, and FIGS. 3 to 9 are perspective views shown in order of steps to explain the method of manufacturing an electrostrictive element of the present invention. 4 is a perspective view of a laminate 8 in which green sheets 7 are laminated, and FIG. 5 shows the laminate 8 being cut by a cutting machine using a wire 11. A perspective view showing the state, FIG. 6 is a perspective view showing the block 9 before forming the insulating layer 3, and FIG.
Figures (a) to (C) are perspective views showing the steps of forming the insulating layer 3, and Figures 8(a) and (b) are perspective views showing the state in which the second insulating layer 5 and the external electrode R4 are formed. FIG. 9 is a perspective view showing a state in which an electrostrictive effect element is cut out from the block 9.

Next, a manufacturing method of an embodiment of the present invention will be explained with reference to FIGS. 3 to 9.

First, a pre-fired ceramic powder made of lead titanate or the like is prepared and dispersed in an organic solvent such as ethyl cellosolve with a small amount of an organic binder such as polyvinyl butyral and a plasticizer such as dioctyl phthalate to create a slurry. . This slurry is made to flow down onto the surface of a polyester film moving at a constant speed by a slip casting method using a doctor blade to form a green sheet with a thickness of 70 μm. Next, after peeling off this green sheet from the polyester film, it was separated into a 70m
A green sheet 7 is prepared by cutting it into m×100 mm width. Next, a mixed paste made by making a paste of a mixed powder of silver powder and palladium powder together with a vehicle is applied to a printing screen having a mask pattern that does not allow the base to pass through.
(not shown) on one side of the green sheet 7 except for one end, and then dried to form the internal electrode layer 2.

Next, every other green sheet 7 on which the internal electrode layer 2 has been formed is rotated 180 degrees, and a desired number of sheets are stacked and pressed from above and below using a hot press to form a laminate 8 as shown in FIG. Since this laminate 8 contains the above-mentioned organic binder and plasticizer, it is heated in a furnace to a temperature of 500° C. to evaporate the plasticizer and decompose and remove the organic binder. Next, this laminate 8 is fired according to the following firing profile (the temperature is raised to 1,120°C at a rate of increase of 5°C/min, the temperature is held at 1,120°C for 2 hours, and then it is naturally cooled). The fired laminate 8 is cut into a block using a cutting machine using a wire 11 (FIG. 5) made of metal, such as a piano wire.
A block 9 as shown in the figure is formed. At this time, the end surfaces 2a of the internal electrode layers 2 are arranged on the left and right surfaces of the block 9 every other layer.
is exposed. Silver paste is applied to the left and right surfaces including this end surface 2a, and a pair of temporary electrode layers 6 are formed as shown in FIG. 7(a).
form. Next, as shown in FIG. 7(b), masking material 1, such as Teflon tape, is pasted on the surface opposite to the surface on which the glass insulating layer 3 will be formed. Using the layer 6, a glass insulating layer 3 is formed every other layer on the internal electrode layer 2 exposed on the front surface of the block 9 by electrophoresis. Next, a masking material 12 is pasted on the surface on which the glass insulating layer 3 was formed in the previous step, and the internal electrodes J exposed on the entire surface of the block 9 are removed using the same electrophoresis method as in the previous step. ! A glass insulating layer 3 is formed on every other layer (FIG. 7(c)).

Next, as shown in FIG. 8(a), it is formed so as to overlap the second insulating layer 5. Next, as shown in FIG. 9, the block 9 is cut onto a chip using a cutting machine using a wire 11 made of metal, such as piano wire, so that the external electrode layer 4 corresponds to one chip. This allows the first
The electrostrictive effect element shown in the figure is obtained.

FIG. 2 is a perspective view of another embodiment of the invention.

In the figure, 1 is an electrostrictive material layer, 2 is an internal electrode layer, 3 is a glass insulating layer, 4 is an external electrode layer, and 5 is a second insulating layer. In this embodiment, the second insulating layer is formed up to the edge of the surface on which the glass insulating layer 3 is formed, which not only increases the insulation resistance of the glass insulating layer 3 and the external electrode layer 4 but also increases the mechanical strength of the glass insulating MI3. It has the advantage of increasing

〔Effect of the invention〕

As explained above, in the present invention, the glass that insulates the ends of the internal electrodes and the vicinity of the outer periphery of the external electrode layer are in contact with each other via the second insulating layer, so that the insulation resistance between the glass and the external electrode layer is increased. This has the effect of significantly improving the reliability of the electrostrictive element.

[Brief explanation of the drawing]

1(a) and 1(b) are schematic front views and cross-sectional views of an electrostrictive effect element according to one embodiment of the present invention, FIG. 2 is a perspective view of another embodiment of the present invention, and FIGS. FIG. 9 is a perspective view showing the steps in order to explain the manufacturing method of the electrostrictive effect element of the present invention, FIG. 3 is a perspective view of a green sheet on which internal electrodes are formed, and FIG. FIG. 5 is a perspective view of the stacked laminate; FIG. 5 is a perspective view showing the state in which the laminate is cut by a cutting machine using a wire; FIG. 6 is a perspective view of a block before forming an insulating layer; Figures (a) to (c) are perspective views showing the process order of forming an insulating layer, and Figures 8 (a) and (b).
) is a perspective view showing a block on which a second insulating layer and an external electrode layer are formed, FIG. 9 is a perspective view showing an electrostrictive effect element cut out from the block, and FIG. 10 is a perspective view showing a conventional electrostrictive effect element. FIG. DESCRIPTION OF SYMBOLS 1... Electrostrictive material layer, 2... Internal electrode layer, 3... Glass insulating layer, 4... External electrode layer, 5... Second insulating layer, 6... Temporary electrode layer , 7...green sheet, 8...
・Laminated body, 9...Block, 11...Wire, 1
2... Masking material. C) (b) Chi 10

Claims (1)

[Claims] A first insulating layer is provided on every other exposed portion of one of the internal electrode layers that is exposed on the opposing side surface of a laminate in which a plurality of electrostrictive material layers and internal electrode layers are alternately laminated. In the electrostrictive effect element in which a glass insulating layer is formed and external electrode layers electrically connecting exposed portions of the internal electrode layer on which the glass insulating layer is not formed are formed on the opposing side surfaces, the glass insulating layer An electrostrictive effect element, characterized in that a frame-shaped second insulating layer is provided between the outer electrode layer and the outer electrode layer, the outer diameter of which is larger than the outer electrode layer, and the inner diameter of which is smaller than the outer electrode layer.