JPS63260122A - Manufacture of laminated ceramic element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method of manufacturing a laminated cefmic element that is effective when applied to the production of a laminated ceramic electrostrictive element or a laminated ceramic capacitor element.

``Prior art'' For example, a method for manufacturing a laminated electrostrictive element is to use a ceramic material such as lead zirconate titanate with a conductive layer 2 applied to the surface in a predetermined pattern to serve as an internal electrode, as shown in FIGS. 4A and 4B. After preparing a raw sheet 1 and a raw sheet 1' for preservation of the same quality without a conductive layer, and stacking them as shown in FIG.
It is pressurized and heated to be crimped, cut into single pieces S of laminated electrostrictive elements as shown in FIG. 8, and fired at 950 to 1100°C.

``Conventional Problems'' According to the above-mentioned conventional method, since the laminated surfaces of each raw ceramic sheet are simply in contact with each other, the pressure applied during crimping causes the firing to occur with misalignment, resulting in a high number of defective products. was unavoidable. Furthermore, it also had the disadvantage of easily causing delamination.

"Means for Solving the Problem" When laminating Cefmic raw sheets, they are laminated and bonded via a resin adhesive layer containing the same ceramic powder as that used for the raw sheets.

"Function" Since the laminated surfaces of each raw ceramic sheet are adhered by the resin adhesive layer, no positional deviation V occurs due to pressure during crimping. Furthermore, since the resin adhesive layer contains ceramic powder made of the same material as the raw ceramic sheet, the difference in thermal expansion between the raw ceramic sheet and the conductive layer is alleviated and peeling (delamination) during firing is prevented.

"Example" Ceramic base made of lead zirconate titanate, 7'=
A raw ceramic sheet is formed into a sheet with a thickness of 0.25 m using the doctor blade method, and a conductive layer (internal electrode) 2 of a predetermined pattern is printed on the surface of the sheet with Ag-Pd metallizing ink using a screen. 1 (Figure 1A
) and one protective sheet 1' (FIG. 1B) made of a homogeneous ceramic green sheet in which the conductive layer 2 is not entirely printed. Next, the same lead zirconate titanate powder used in the ceramic paste was mixed with a resinous adhesive to form an adhesive layer 3 on the surface of each green ceramic sheet 1 to a thickness of 10 μm. The raw sheets 1 are sequentially laminated and glued through the layer 8, and the protective sheet 1' is placed on top.
(Fig. 2). Next, this glued area of 1m
The body is thermocompression bonded at a temperature of 80'C and a pressure of 81/d. Furthermore, this crimped body is cut into single pieces S as shown in FIG. 3, and fired at 950 to 1100°C.

After firing, a laminated electrostrictive element is completed by applying conductive paint (not shown) such as silver to both sides and wiring them so that they are electrically parallel.

Next, the delamination and voltage-displacement characteristics of the laminated electrostrictive element obtained by the method of the present invention and the electrostrictive element obtained by the conventional method without using an adhesive layer were measured, and the results are as follows. As shown in the table, the laminated electrostrictive element produced by the method of the present invention was found to have a lower failure rate and better voltage-displacement characteristics than those produced by the conventional method.

In the above example, the thickness of the adhesive layer 3 is desirably less than half the thickness of the 7 m raw ceramic sheet; if it is thicker than this, delamination is likely to occur after firing.
In addition, the amount of ceramic powder packed into the resin laminating agent is 20
A range of ~60% by weight is desirable; if it is less than 20% by weight, it will not be possible to sufficiently alleviate the distortion caused by thermal expansion between the laminated surfaces of the 6 green sheets, and it has been confirmed through experiments that if it exceeds 60% by weight, the adhesive strength will drop significantly. did.

Furthermore, although the above example deals with a laminated electrostrictive element that is displaced in the longitudinal direction (laminated direction) by voltage application, it goes without saying that the present invention can also be applied to a laminated capacitor element used as a high-capacity i-element.

``Effects'' According to the method of the present invention, each raw ceramic sheet can be bonded and laminated, so the lamination work is easier than in the conventional method, and there is no misalignment due to the pressure applied during crimping, and there is no dull lamination during firing. This has the advantage of being able to suppress the occurrence of porosity, thereby improving the yield and, in turn, making it possible to provide the planted laminated type sewomic element with excellent reliability at a low cost.

[Brief explanation of the drawing]

1A and 1B are explanatory diagrams showing a green ceramic sheet with an adhesive layer on the upper surface and a protective sheet used in an example of the present invention, and FIG. 2 is an explanatory diagram showing a plurality of green sheets shown in FIGS. FIG. 8 is an explanatory diagram showing the state of lamination with a protective sheet, and FIG. 8 is a perspective view of a laminated ceramic element obtained by cutting the laminate shown in FIG. 2. @4 Figures A and B and Figure 5 respectively relate to conventional examples and are explanatory diagrams shown similarly to Figures 1A and B and Figure 2 above. Note that the same numbers in the figures indicate the same parts. DESCRIPTION OF SYMBOLS 1... Cefmic raw sheet, 1'... Cefmic raw sheet for protection, 2... Conductive layer serving as an internal electrode, 8...
・Resin adhesive layer Figure A Figure 1 B Figure 2 Figure 4 A Figure 4 B Figure 5 Figure 3

Claims (1)

[Claims] A laminated ceramic element characterized in that a plurality of raw ceramic sheets each having a conductive layer applied to the surface thereof are laminated and bonded through a resin adhesive layer containing an appropriate amount of the same ceramic powder as that used for the sheets and pressed together. Production method.