JPS58196073A - Electrostrictive effect element - Google Patents

Abstract

PURPOSE:To facilitate the manufacture of a lamination type electrostrictive effect element by a method wherein holes are opened on a film of electrostrictive material, and this hole is filled with conductor. CONSTITUTION:After being coated over a Mylar film and dried, the electrostrictive material is exfoliated from the Mylar film, and accordingly a green sheet 31 is obtained. Next, the holes 32 and 32' are opened at symmetrical positions of the green sheet 31, and platinum paste is coated by leaving the part 33 around the hole 32. Then, the sheet 31 and inversed one at 180 deg. are laminated alternately and formed into an integral body by thermal press, thus sintered. The platinum paste turns into platinum electrodes 42 and 42' being connected between up and low parts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an electrostrictive element that utilizes the longitudinal effect.

When an element having a multilayer chip capacitor structure as shown in FIG. 1 is constructed using a material having a large electrostrictive effect, an electrostrictive effect element that generates a large strain at a low voltage can be obtained. That is,
As shown in FIG. 1(a), a film made of electrostrictive material or F
Positive internal electrode plate 2. Negative internal electrode &2'
The structure is such that the tubes are alternately sandwiched and stacked, and the internal electrode plates 2 and 2'l are connected to external electrodes 3 and 3', respectively. However, in the above-mentioned conventional electrostrictive effect element, as can be understood from the plan view of wJ(b), the overlapping part between the internal electrode plates 2 and 2' is smaller than the total area of the element surface, and the peripheral part The two electrodes do not overlap. Therefore, when a voltage is applied between the external electrodes 3 and 3', the electric field strength is strong only at the overlapping portion of the electrodes 9, while the electric field strength is weak at the peripheral portion. For this reason, there is a drawback that not only the peripheral portion of the single layer does not deform, but also the deformation of the entire element is inhibited, making it impossible to obtain the amount of strain specific to the material.

Furthermore, stress concentration occurs at the boundary between the deformed part and the non-deformed part, and there is also the disadvantage that the element is mechanically destroyed by high voltage application, <υ return application, or long-term part stress.

In order to improve the above-mentioned drawbacks, Figs. 2(a) and (b)
It is conceivable to have a structure as shown in the figure below. That is,
As shown in Figure (a), internal electrode plates 2.2' are alternately formed and laminated on the entire surface of the gland (or thin plate) 1 made of electrostrictive material, and the ends of the plurality of internal electrode plates 2 are mutually connected. The structure is such that the internal electrode plates 2' are connected to the external terminal AK, and the plurality of internal electrode plates 2' are connected to the external terminal BK. Therefore, as shown in the same figure (b), since it is formed on the entire surface of the internal electrode plate 2 and the r/fix element,
& When voltage is applied between pole terminals A and B, the film 1 of electrostrictive material
The electric field distribution inside becomes uniform, the element deforms uniformly, and stress concentration does not occur. That is, the element Fi exhibits deformation 'jl inherent to the material and becomes difficult to break. However, since the internal electrode plates 2.2' are close to each other, it is very difficult to electrically connect the internal electrode plates 2 to each other and the internal electrode plates 2' to each other.

In view of the above-mentioned circumstances, an object of the present invention is to propose a structure of an electrostrictive effect element in which internal electrode plates formed on the entire surface of the element can be alternately and easily and stably connected to external electrode plates. .

In the electrostrictive effect element of the present invention, holes are formed at symmetrical positions starting from the center of a thin plate of an electrostrictive material having the same dimensions, and the holes are filled with a conductor, and one of the holes is forming an internal electrode plate on the surface of the Wa or sister thin plate of the electrostrictive material, leaving the peripheral part of
The film or thin plate of the electrostrictive material is alternately inverted and stacked, and the Il# image is that every other internal electrode plate is connected to each other via the conductor in the hole.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 3 is a sectional view showing one embodiment of the present invention. That is, first, magnesium lead niobate Pb (Mgx/s
A small amount of organic binder is added to a pre-fired powder of an electrostrictive material whose main component is Nbz7lu)On, a slurry is prepared by dispersing this in an organic solvent, and the slurry is used to manufacture ordinary multilayer chip capacitors. The green sheet 31 is obtained by applying the green sheet to a thickness of several 100 microns on a Mylar film using a commercial machine, drying it, and then peeling it off from the Mylar film. Holes 32 and 32' are bored at symmetrical positions on the scissor green sheet 31, and a portion 33 around the hole 32 is left as shown in FIG. Platinum paste is applied and the holes 32 and 32' are filled with platinum paste i.If the green sheet is rotated 1806 times, as shown in FIG. The parts that are not coated will be left and right reversed.The parts shown in (&) and the parts shown in () are laminated alternately and integrated by heat pressing, and then heated at a temperature of 1200℃ for about 1 Time to sinter. As shown in FIG. 4, the platinum paste filled in the holes of each layer of the sintered ceramic is connected between the upper and lower layers to form platinum electrodes 42, 42'.

Therefore, the platinum paste of each layer is connected every other layer. That is, the internal electrode plates 43 sandwiched between the electrostrictive material films 41 of each layer are alternately connected to platinum electrodes 42 and 42' penetrated through the two holes, respectively.

In this example, the cross section 81j of the element is approximately 0.1 m from each other of the internal electrode plates 2 of each layer of 10-1, and the diameter of the through hole is (11
5 m, and the diameter of the portion 33 not coated with platinum paste shown in FIG. 3 was 0.6 m, so that the internal electrode plates 43 were connected alternately and no short circuit between the electrodes occurred.

The electrostrictive effect element configured as described above is easy to manufacture and has the effect of generating a large strain by applying a low voltage. That is, the present invention provides a structure suitable for producing on an industrial scale a laminated electrostrictive element having an internal electrode plate having a cross-sectional area equal to the cross-sectional area of the element.

[Brief explanation of the drawing]

Figures 1 (a) and (b) are cross-sectional views and plan views showing an example of a conventional r-chip capacitor type electrostrictive effect element; Figure 9.3 is a cross-sectional view and a plan view showing a laminated multilayer electrostrictive element with internal electrode plates and tubes formed on the entire surface of a thin plate. FIG. 4 is a plan view showing an example of a platinum paste printing pattern, and FIG. 4 is a partially longitudinal blood sectional view showing an embodiment of the present invention. In the figure, 1... A film (or thin plate) of electrostrictive material, 2
．． 2'...Internal electrode plate, 3.3'...External electrode, 3
1...green sea), 32.32'...hole, 33
... Part where platinum paste is not applied, 41 ... Film (or thin plate) of electrostrictive material, 42.42 ... Platinum electrode,
43.--Internal electrode plate. Figure 7 I Wipe 2 Figure 2 (2'

Claims (1)

[Claims] Holes are formed at symmetrical positions with respect to the center of a membrane or thin plate of electrostrictive material having the same dimensions, and the holes are filled with a conductor, leaving the peripheral area of one of the holes and forming the membrane of electrostrictive material. Alternatively, an internal electrostrictive plate is formed on the surface of the thin plate, and a film of the electrostrictive material or Fi□
An electrostrictive effect element characterized in that thin plates are alternately inverted and stacked, and every other internal electrode plate is connected to each other via the conductor in the hole.