JPH02164085A - Electrostriction effect element - Google Patents

Abstract

PURPOSE:To eliminate development of cracks or splits in use at a high frequency and to improve reliability and producibility of an element by interposing a mixture of an inner electrode material and an electrostriction ceramic member to all the surfaces whereon the inner electrode and the electric ceramic member are in contact with each other and by burning them integrally. CONSTITUTION:Paste which is mainly composed of a mixture 20 which is made by mixing pre-burned powder of an electrostriction material which is the same as that of an electrostriction sheet 1 with power of silver and paradium mixed at a specified weight ratio is applied and formed to one side of the electrostiriction sheet 1 through screen printing, etc. Then, a specified number of the electric distortion sheets 1 are laminated making these formation surfaces in the same direction and integrally burned through heat-press. A side is thereafter cut to form a laminated body 10 of a square prism having an externally exposed end of the inner electrode 2. The electrostriction sheet 1 and the inner electrode 2 thereby adhere each other through the mixture 20 and adhesion is improved. A highly reliable electrostriction element having a large tensile strength can be obtained without delamination during burning in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a stacked electrostrictive element that utilizes the electrostrictive longitudinal effect.

(Prior Art) Conventionally, this type of electrostrictive effect element has the following characteristics, as shown in FIG.
A laminate formed by laminating a plurality of sheets or thin plates (hereinafter referred to as electrostrictive sheets)+1 made of electrostrictive material, each of which has an internal electrode material (hereinafter referred to as internal electrode) 12 formed on one side; An insulator 13 is formed every other layer on the internal electrode 2 exposed at one corner of the side surface, and a first insulator 13 is formed from above the insulator 13.
An insulator formed on the exposed portion of the internal electrode 12 on which the insulator 13 was not formed is formed on the external electrode conductor (hereinafter referred to as external electrode) 14 and on one corner of the other side surface that is almost opposite to the one corner of the aforementioned side surface. object 13a, second external electrode 14a formed thereon, and external electrodes 14, 14a on both sides.
Lead wires 15, 15a connected with solder 16.16a to
It was composed of.

(Problems to be Solved by the Invention) In the conventional electrostrictive effect element described above, the electrostrictive sheet 11 and the internal electrode 12 made of different materials are laminated and both are fired at the same time. Delamination may occur during firing, or electrostrictive seams may occur after firing.
Microcracks were found to have occurred at the interface between the internal electrode 1 and the internal electrode 12.

In addition, the electrostrictive sheet (■) and the internal electrode 12 have poor chemical bonding, and most of them are mechanically bonded due to anchor effects, etc., and the tensile strength of the element is small, so that it is difficult to connect with a steep direct current or a rising pulse F. It is weak when applied with voltage or used at high frequencies, and has many problems such as breaking and cracking.

An object of the present invention is to provide a highly reliable electrostrictive effect element that solves the above-mentioned drawbacks.

[Means to solve the problem]

The electrostrictive effect element f of the present invention has a sintered layer of a mixture of the electrostrictive ceramic member and the internal electrode between the electrostrictive ceramic member and the internal electrode.

[For production]

Since a mixture of these two materials is applied to the interface between the electrostrictive sheet and the internal electrodes and fired, the electrostrictive sheet and internal electrodes adhere to each other through the mixture, increasing the adhesive force and firing. A highly reliable electrostrictive element with high tensile strength and high tensile strength can be obtained without delamination.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a first embodiment of the electrostrictive effect element of the present invention.

In this embodiment, a sintered layer of a mixture 20 of the electrostrictive sheet 1 and the internal electrode 2 is provided between the electrostrictive sheet 1 and the internal electrode 2.

Next, the manufacturing method of this example will be explained.

First, for example, nickel, lead niobate Pb (NiQN
A trace amount of an organic binder is added to a pre-fired powder of an electrostrictive material whose main component is b%) 03, and a slurry is prepared by dispersing this in an organic solvent. Electrostrictive sheet 1 with a thickness of about 100μ
form. First, on one side of this electrostrictive sheet 1, 30 to 70 wL of pre-sintered powder of the same electrostrictive material as the electrostrictive sheet 1 was added to a mixture of silver powder and palladium powder at a weight ratio of 7:3.
A paste containing the mixture 20% mixed as a main component is applied and formed to a thickness of about 5 mm by screen printing or the like.

Thereon, an internal electrode 2 made of only silver:palladium (7:3) is formed in a similar manner to a thickness of about 10 -, and about 5 scales of the mixture 20 are further formed thereon.

Next, a predetermined number of electrostrictive sheets 1 are laminated so that these formed surfaces are in the same direction, and are integrated by heat pressing. After baking at a temperature of about 1100° C. for about 2 hours, the sides are cut. A prismatic laminate 10 in which the ends of the internal electrodes 2 are exposed to the outside is formed. An insulating material 3 such as glass is formed every other layer on the internal electrode 2 exposed on the first side surface of the laminate 10, that is, the left side surface, and a conductive paste containing silver powder as a main component is applied thereon. 1 external electrode 4 is formed. 1st
Similarly, an insulator 3a is formed on the inner electrode 2 on which no insulator 3 is formed on the second side surface opposite to the side surface of the right side, that is, the first side surface on the right side, and a second outer electrode 4a is formed on the inner electrode 2 on which the insulator 3a is not formed. form.

In this embodiment, the solder 6, 6 is connected to the voltage supply section (not shown).
Lead wires 5.a are respectively connected to external electrodes 4.4a.
When a voltage is applied between 5a, a voltage is applied to both ends of all electrostrictive sheets 1 between internal electrodes 2 through external electrodes 4.48, and a strain in the XY force directions shown by the arrows is generated in the entire element. It is something.

FIG. 2 is a longitudinal sectional view of a second embodiment of the electrostrictive effect element of the present invention.

This embodiment has a leadless structure, and its manufacturing method is the same as that of the first embodiment, but this structure has a leadless structure with external electrodes 4, 4a.
The difference is that each is formed by extending to one end face.

(Effects of the Invention) As explained above, the present invention provides an X When the tensile strength of this element was measured by applying a load in the Y direction, it was confirmed that the strength was approximately 2 to 4 times higher than when no mixture was involved, and it was also confirmed that delamination and microcracks occurred during firing. It is also possible to eliminate cracks and cracks during use at high frequencies, which has a significant effect on improving device reliability and productivity.

[Brief explanation of the drawing]

1 and 2 are longitudinal cross-sectional views showing one embodiment of the electrostrictive effect element of the present invention, and FIG. 3 is a longitudinal cross-sectional view showing a conventional example of the electrostrictive effect element. 1... Electrostrictive sheet, 2... Internal electrode, 3.
3a---Insulator, 4, 4a... External electrode, 5.
5a---Lead wire, 6,6a・-Solder, 10-・
- Laminate, 20... mixture.

Claims (1)

[Claims] 1. A laminated sintered body in which sheet-shaped electrostrictive ceramic members and internal electrode conductors are alternately stacked, and one end surface of the internal electrode conductor exposed on the opposing side surfaces of the laminated sintered body is formed in one layer on each side. The electrostrictive ceramic element includes a glass insulating layer that is insulated at intervals, and a pair of external electrodes that electrically connect the other exposed end surface of an internal electrode conductor to form two comb-shaped electrodes. between the member and the internal electrode conductor,
An electrostrictive effect element characterized by having a sintered layer of a mixture of both.