JPS60160698A - Multilayer ceramic board - 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 The present invention relates to a multilayer ceramic substrate, and particularly to improvements in its external electrodes.

In recent years, from the viewpoint of cost performance, attempts have been made to use inexpensive silver-palladium pastes, silver-platinum pastes, etc. instead of expensive gold pastes as conductor pastes for multilayer ceramic substrates.

Normally, insulator green/sheet 3
When the internal electrode 1 is formed by filling the hole with a silver-palladium paste or silver-platinum thread paste in a T-shaped cross section as shown in Fig. 1, the land of the internal electrode 1 is used. No phenomena such as peeling or blistering on the side parts were observed. However, when the above-mentioned paste is used as the external electrode 2, undesirable phenomena such as peeling and blistering of the land portion exposed to the outside of the external electrode 2 occur.

Therefore, it has been difficult to use a silver-palladium paste or a silver-platinum paste as an external electrode.

The purpose of the present invention is to solve these drawbacks and provide a multilayer ceramic substrate that uses silver-palladium paste, silver-platinum paste, etc. as the external electrode and does not cause peeling or blistering of the land portion of the external electrode. It's about doing.

According to the present invention, an external electrode is provided in a reduced size on the outermost layer of a multilayer ceramic laminate, and an insulating sheet having an opening window smaller than the external shape of the external electrode is combined with the opening window and the external electrode into one. A multilayer ceramic substrate characterized by laminating more than one layer is obtained.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 to 4. As shown in Fig. 2, land-shaped internal electrodes 5 are printed on both sides for vertical conduction of the green sheet through via holes 4 formed by filling the through holes provided at desired positions of the green sheet with conductive paste. The insulator green sheet 6 and the via hole 4 are connected to each other, and the dielectric green sheet 8 and the dielectric green sheet 8 on which internal electrodes 7a for forming a capacitor are printed on the bottom surface are connected to the protruding upper end of the via hole. An insulator green sheet 9 with an internal mold $7b printed on the bottom surface to form a capacitor, and an insulator green sheet 1 with a resistor lO printed on the top surface.
A laminate 12 is formed by stacking each sheet with the upper and lower two layers shown in FIG. 2 removed. Next, on the outside of the outermost layer of this laminate 12, an insulator is provided with a window ''13 consisting of a through hole smaller than the shape of the external electrode 5 at the same position corresponding to the external electrode 5 formed on the outermost layer. Stack the green sheets 14 at a temperature of 200 kg/c and a pressure of 200 kg/c.
Thermocompression bonding is carried out for 20 minutes under rA conditions. Next, debinding was performed under the conditions of a temperature increase rate of 5°C/hour, a maximum temperature of 450°C, and a maximum temperature holding time of 4 hours, and the maximum temperature was 85°C.
The multilayer ceramic substrate shown in FIG. 3 was obtained by sintering with a temperature profile in which the temperature was raised to 0° C. and then cooled to room temperature.

In this multilayer ceramic substrate of the present invention, the periphery of the land where external electrodes are likely to peel or bulge is covered with an insulating green sheet
In this example, the case where the number of insulating green sheets laminated outside the outermost layer to suppress peeling and blistering is one layer is described. As shown in FIG. 4, when we tried manufacturing a case with two or more layers, even better results were obtained than in the case of one layer.

As described above, the present invention solves the conventional drawbacks such as peeling and blistering of the external electrode when silver-palladium paste or silver-platinum paste is used as the external electrode, and silver-palladium paste, which is cheaper than gold paste, is used as the external electrode. It is possible to use paste, silver-platinum paste, etc., which has the advantage of reducing costs.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an electrode forming layer of a conventional multilayer ceramic substrate. FIG. 2 is a sectional view of a multilayer ceramic substrate before lamination according to an embodiment of the present invention. FIG. 3 is a cutaway perspective sectional view showing the main part of FIG. 2 after completion. 4th [F] is a sectional view of a multilayer ceramic substrate before lamination according to another embodiment of the present invention. l...Internal electrode, 2...External electrode, 3
...Insulator green / sheet, 4 ... Via hole & 5 ... Internal electrode board, 6, 9
．． 11...Insulator green/sheet, 7a, 7b
...Internal electrode (of conotensa formation), 8...
... Dielectric green sheet, 10... Resistor, 12... Laminate, 13. Old... Window section, 14.
...Insulator green/sheet with window, 15.
・・Representative Patent Attorney Susumu Uchihara

Claims (1)

[Claims] An external electrode provided exposed on the outermost layer of a multilayer ceramic laminate and an insulating sheet having an opening window smaller than the external shape of the external electrode are laminated in one or more layers including the opening window and the external electrode. A multilayer ceramic substrate featuring: