JPS61272984A - Electrostrictive effect element - Google Patents

Abstract

PURPOSE:To solder a lead wire by a small quantity of a solder by laminating and disposing electrostrictive material layers while being held by internal electrode layers, extending an external electrode, which is connected electrically at every other layer with internal electrodes by conductors, onto a protective layer and connecting the external electrode to a lead terminal. CONSTITUTION:An electrostrictive effect element consists of electrostrictive material layers 1 made of ceramics composed of titanate zinc zirconate in 0.1m thickness, internal electrode layers 2 using a silver-palladium alloy in 5mum thickness and insulating protective films 3, which insulate the end surfaces of the internal electrode layers 2 at every one layer and are composed of a glass film in 15mum thickness. External electrodes 4 to which silver paste is applied are mounted outside the electrostrictive effect element, and connected electrically to lead wires 5 such as polyurethane coated copper wires having a 0.23fmm diameter by solder 6 such as eutectic solder. Solder 6 connecting the external electrodes 4 and the lead wires 5 is connected to the external electrodes 4 formed extended onto a protective layer 7 shaped to an outermost layer as a piezoelectrically inactive dummy layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostrictive effect element used in mechatronic equipment, and more particularly to a terminal extraction structure of a laminated electrostrictive effect element.

[Conventional technology]

Conventionally, a stacked electrostrictive effect element has a structure shown in FIG. In FIG. 3, 1 is a ceramic electrostrictive material layer made of lead zirconate titanate having a composite perovskite structure, and 2 is an internal electrode layer using a silver-palladium alloy.

Reference numeral 3 denotes an insulating protective film coated to insulate the end faces of the internal electrode layers 2 every other layer. Reference numeral 4 designates external electrodes deposited to electrically connect every other internal electrode layer 2.

Normally, in order to apply an electric signal to the electrostrictive element, a lead wire 5 is attached to the external electrode 4 via a solder 6.

[Problems that the invention attempts to solve]

It is best to use as little solder as possible during this soldering process. The reason for this is that if the amount of solder is large, stress will be generated between the solder 6 and the external electrode 4 when the electrostrictive element expands and contracts during operation, reducing reliability during operation.

In order to solder and connect lead wires with a small amount of solder, the wire diameter of the lead wires must be made small. Therefore, as the wire diameter becomes smaller, there are disadvantages in handling such as the lead wire being more likely to break.

[Means for solving problems]

An object of the present invention is to provide an electrostrictive effect element that eliminates such conventional drawbacks.

The electrostrictive effect element of the present invention is a laminate in which an electrostrictive material layer is sandwiched between internal electrode layers and has a protective layer made of an electrostrictive material in contact with two internal m-pole layers, upper and lower. The end face of the internal electrode layer exposed on the side surface is partially covered with an insulating protective film,
Further, external electrodes electrically connected to internal electrodes l- every other layer by conductors are extended onto the protective layer, and lead terminals are electrically connected on the external electrodes extended and formed on the protective layer. It is characterized by

〔Example〕

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is a perspective view of an electrostrictive element according to an embodiment of the present invention.

In the figure, 1 is an electrostrictive material layer made of ceramic lead zirconate titanate with a thickness of 0.1 m, and 2 is a silver layer with a thickness of 5 μm.
Internal electrode layer using palladium alloy, 3 is internal electrode layer 2
4 is an insulating protective film made of a glass film with a thickness of 15 μm, insulating the end face of every other layer, 4 is an external electrode coated with silver paste,
5 is a lead wire such as a polyurethane-coated copper wire having a diameter of 0.2 m, and 6 is a solder such as eutectic solder for electrically connecting the external electrode 4 and the lead wire 5. The solder 6 that connects the external electrode 4- and the lead wire 5 is connected to the external electrode 4, which is extended and formed on a protective layer 7 provided as the outermost layer as a piezoelectrically inert dummy layer. . .

Next, this embodiment will be explained in order of manufacturing steps.

First, a ceramic calcined 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 a binder such as polybutyral resin and a plasticizer such as dioctyl heptalate to form a slurry. .

The slurry was fluidly applied onto a 100 μm thick polyester film by a slip casting method using a doctor blade to form a 70 μm thick green sheet serving as an electrostrictive material.

Next, after peeling off the green sheet from the polyester film, an internal electrode layer 2'ft is formed in a predetermined shape by screen printing with a conductor paste such as silver-palladium paste.

A desired number of green sheets are stacked and pressed together from above and below using a hot press to form a laminate of electrostrictive material.

When stacking the green sheets, 20 to 30 green sheets on which no internal electrode layer is formed are stacked above and below the green sheet on which the internal electrode layer 2 is formed, respectively, to form a protective layer as a dummy layer.

Next, the organic binder contained in this laminate is decomposed at high temperature and removed by evaporation, and then the temperature is increased to 1°C at a rising speed of 5°C/min.
The temperature is increased to 120°C and held at 1120°C for 2 hours to perform sintering.

The sintered laminate is cut into a desired thickness using an internal blade cutter to produce a sliced plate as shown in FIG. 2(a). Since the ends of the internal electrode layers 2 are exposed on the cut surface of the slice plate, in order to make electrical connections every other layer, the ends of the internal electrode layers 2 are glass-covered every other layer by electrophoresis. An insulating protective film 3 consisting of the following is deposited and formed.

Next, as shown in FIG. 2(b), silver paste is formed by screen printing or the like to extend the external electrode 4 up to the protective layer 7 as a dummy layer. A wire with a diameter of 0.0 mm is soldered onto the external electrode 4 formed on the protective layer 7 in this manner. ．． 5 r
The lead wire 5 of rtnφ is connected to fabricate an electrostrictive effect element.

〔Effect of the invention〕

As explained above, since the lead wire of the electrostrictive effect element of the present invention can be used with a diameter of 0.5 mm or more, the reliability of the lead wire can be improved without cutting it in handling. .

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the electrostrictive effect element of the present invention, Fig. 2(a)
, (b) is a perspective view of a slice plate produced in the manufacturing process of the electrostrictive effect element of the present invention, and FIG. 3 is a perspective view of a conventional electrostrictive effect element. 4-(Outside #S Dendanji 81 Figure 3 Figure

Claims (1)

[Claims] The internal electrode layer exposed on the side surface of the laminate has an electrostrictive material layer sandwiched between internal electrode layers and a protective layer made of an electrostrictive material in contact with the upper and lower internal electrode layers. External electrodes whose end surfaces are partially covered with an insulating protective film and which are electrically connected to the internal electrode layer every other layer by conductors are extended on the protective layer and formed to extend on the protective layer. An electrostrictive effect element characterized in that it is electrically connected to a lead terminal on an external electrode.