JPS5830734B2 - Electrode coating method for ceramic elements - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode coating method for a ceramic element such as heat-resistant barium titanate-based porcelain, which reduces variation in electrode coating dimensions and coats an electrode with a thick electrode film. An electrode coating method is provided.

When applying electrodes to chip capacitors, etc., the insulation resistance of the element surface is determined by the shortest distance between the electrodes, and due to the design and appearance of the circuit board on which these parts are attached, care must be taken to ensure that the electrodes do not become partially short. As shown in Figure 1, it is desirable to apply the electrode 2 to the end of the ceramic element 1 straight so that the distance from the end face is equal, and from the standpoint of soldering properties, it is desirable that the electrode film be thicker. ing.

Conventionally, silver, silver, <radium,
Paint-like materials such as gold are used.

In order to improve the accuracy of the electrode dimensions, the electrode material was coated with a quick-drying solvent such as toluene to a viscosity of 300 to 5 ooc, p, s.
The end portion of the ceramic element to be coated is dipped in the paint-like electrode material to a certain size and applied.

In such a case, the dimensional accuracy is good, but since the electrode material is thin, the electrode film that is applied at one time is thin, and it is necessary to reapply it after drying, and since the solvent dries quickly, the viscosity tends to fluctuate and is difficult to manage.

Furthermore, when the viscosity is increased with a quick-drying solvent, the applied electrode film becomes thicker, but the viscosity is more likely to fluctuate, making viscosity control more difficult.

Furthermore, if a slow-drying solvent is used to increase the viscosity, there will be little variation in viscosity and the electrode film can be made thicker, but as shown in Figure 2, the electrode material bleeds into areas where it is not applied. arise.

In this case, if the ceramic element is heated and dip-coated, the electrodes will have relatively good dimensional accuracy, but the solvent in the electrode paint will evaporate and the viscosity will fluctuate dramatically, making control difficult.

The present invention eliminates the above-mentioned conventional drawbacks, and uses a heat-resistant jig for holding the ceramic element to be coated.
By heating the holding jig in advance, holding the central part of the ceramic element with the holding jig, and applying electrode material to the ends of the element by dip coating, an electrode with good dimensional accuracy and a thick coating film can be obtained. This paper attempts to propose an electrode coating method.

The method of the present invention will be explained below along with examples.

Example 1 This will be explained with reference to FIG.

First, the material of the porcelain element 3, which is the object to be coated, is barium titanate porcelain, and its dimensions are vertical length 1 = 1.9 mm.
, width W=1.1 mm, and thickness t=0.6 mm.

The holding jig 4 is a stainless steel tweezers, and the height of the holding part is h-0.4 mm, and the width 11 is 4 mrn.

Then, the holding jig 4 is heated to 200° C. in advance, and the vertical center of the ceramic element 3 is quickly clamped as shown in FIG. 4000 (, P, S, depth Q, porcelain element 3 in a 3 mm silver paint bath (not shown)
One end surface of the element 3 is immersed, and after another 2 seconds, the holding jig 4 is turned over and the other end surface of the element 3 is immersed.

After the electrode material is applied to both end faces of the ceramic element 30 in this manner, it is heated and dried until the electrode surface is not scratched even when touched with a finger, and then the ceramic element 3 is removed from the holding jig 4 and baked at a high temperature.

Example 2 The dimensions of the porcelain element are 1 = 4.3 mm, W = 1.1
Coating was carried out in accordance with Example 1, except that t=1 mm and the heating temperature of the holding jig was 300°C.

Example 3 The dimensions of the ceramic element are l = 1.1 mrn, W = 0
．． 8mm, t=0.5mm, heating temperature of holding jig 10
The electrode material was applied at 0°C in the same manner as in Example 1 except that the temperature was 0°C.

In each case of Example 1.2.3, the electrode material viscosity was 7.
Compared to the cases of 00C, P, and S, the thickness of the electrode coating film once applied was 2.5 times or more, and the coating appearance showed no significant bleeding and little dimensional variation.

As described above, the present invention is a method in which a holding jig for a ceramic element is heated in advance, the central part of the ceramic element is held by this holding jig, and an electrode material is dip-coated on the end of the element.
The heat from the holding jig is transmitted from the center of the porcelain element to the edges, so even if the electrode material applied to the edges is a slow-moving solvent with high viscosity, it will dry out from the center and bleed. It is possible to coat a high-quality electrode with less fluctuation in the viscosity of the electrode material, and with good dimensional accuracy and easy to thicken the electrode film.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a porcelain element with electrodes accurately applied, Figure 2 is a perspective view of a porcelain element with electrode bleeding, and Figure 3 is a schematic diagram of an apparatus for explaining the method of the present invention. be. 3...Porcelain element, 4...Holding jig.

Claims (1)

[Claims] 1. A method for applying electrodes to a ceramic element, which comprises holding the central part of the ceramic element with a heat-resistant holding jig that has been heated in advance, and applying electrode material to the ends of the ceramic element by dip coating.