JPH05275272A - Method for forming terminal electrode of electronic ceramic component - Google Patents

Abstract

PURPOSE:To achieve a method for forming terminal electrodes requiring no plating process, by coating both terminal ends of a component with an alloy paste containing specific Cu-Ni as the principal constituent before baking the component, and thereafter simultaneously carrying out the baking of the component and the terminal electrodes. CONSTITUTION:On the end faces of the element assembly of a BaTiO3-CaZrO3 multilayer ceramic capacitor (a chip-like component made by printing an internal electrode 5 on ceramic green sheets 1 and laminating them, which is already degreased), a borosilicate glass frit is mixed into and kneaded with fine powder of a 40 to 60wt% Cu-60 to 40wt% Ni alloy to prepare a paste as terminal electrodes 2 for capacity extraction. Then, the Cu-Ni alloy paste is applied. Thereafter, the component is baked with a heat pattern in a H2/N2 atmosphere. By this, an electronic component such as a ceramic capacitor can be manufactured which allows the Ni-Sn plating process to be omitted, and in addition, which is excellent in electrical characteristics and solder leach resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a terminal electrode of a ceramic electronic component having a terminal electrode mounted on a substrate, such as a chip type ceramic capacitor.

[0002]

2. Description of the Related Art Ceramic electronic parts mainly consist of ceramics composed of various oxides. Since ceramics are fired in the air, noble metals such as Pd and Ag are used for the electrodes so that they are not oxidized. On the other hand, a ceramic electronic component, especially a chip type, is soldered to connect to a substrate electrode. For this reason, a terminal electrode (mainly an Ag electrode) is applied, and then Ni and Sn plating is applied to form an electronic component. That is, in the conventional method, as shown in the outer view of FIG. 5A and the sectional view of FIG. 5B, the ceramic body 1 is fired, and the terminal electrodes 2 made of a metal such as Pt and Ag are applied to both ends of the ceramic body 1. After the electrode 2 is baked, Ni plating 3 and Sn plating 4 are applied to the surface of the electrode 2 for finishing. In the figure, 5 is an internal electrode.

In recent years, due to the fierce cost competition in the electronic component industry, base metalization of electrode materials is being used for internal electrodes and some terminal electrodes. It is necessary to deal with the selection of electrode materials, control of ceramic firing atmosphere, development of reduction resistant dielectric materials, and strengthening of internal / external electrode bonding when base metals are used for electrodes, and appropriate measures are reported. Has been done. However, as mentioned above, there is a problem that the manufacturing process itself is complicated and there are many, so there is a demand for a reduction in the number of processes. In particular, since the phenomenon of deterioration of capacitor characteristics due to plating occurs, a manufacturing process that does not require a plating process is realized. Have great expectations.

[0004]

Thus, it is a current problem to provide a method of forming a terminal electrode that avoids the deterioration of capacitor characteristics due to the complexity of the manufacturing process and plating.
That is, in the manufacturing process, it is possible to solve the multilayering and uneconomical heat history of firing the terminal electrode after firing the ceramic, and to perform the ceramic firing and the terminal electrode firing in one heat treatment, while the plating process Then
Even with a fired and densified ceramic, it is unavoidable that a trace amount of the plating solution remains, which causes moisture resistance deterioration and insulation deterioration. Therefore, there is a demand for a method of forming a terminal electrode that does not undergo a plating process. The present invention has been made to satisfy the above-mentioned problems at the same time. A Cu-Ni alloy paste is used as a terminal electrode, and after the paste is applied to a ceramic material, ceramic firing and terminal electrode baking are simultaneously performed, and a plating step is not required. It is an object of the present invention to provide a method for forming a terminal electrode.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has the following structures. That is, in manufacturing an electronic ceramic component in which a base metal is used as an internal electrode and both electrodes thereof are arranged, 40 to 60 before firing the component.
A method of forming a terminal electrode, characterized in that an alloy paste containing wt% Cu-60 to 40 wt% Ni as a main component is applied to both ends of a terminal of the component, and then the component is baked and the terminal electrode is baked at the same time. is there.

FIG. 1 shows a schematic cross section of the terminal electrode of the present invention. As shown in the figure, the present invention is a method in which the terminal electrons 2 are applied to the ceramic body 1 and then firing and baking of the ceramic are simultaneously performed. Humidity resistance and insulation deterioration are eliminated.

A more detailed description is as follows. The material of the terminal electrode is limited due to its semi-compatibility, that is, its solid solubility in the Sh-Pb alloy. On the other hand, a material having good heat resistance is desired from the standpoint of half-eating. As a result of various studies from such a viewpoint, in the present invention, an alloy containing Cu—Ni as a main component is used, and as shown in FIG.
It has been found that 0-60 wt% Cu-60-40 wt% Ni alloy paste is optimal for this purpose. If there is a large amount of Cu, there is a problem with the heat resistance at half, and if there is a large amount of Ni, there is a problem with the solid solubility in the half, and 40-60 wt% Cu-60-
This is because the range of 40 wt% Ni is optimal for the balance of both components. Moreover, when the paste is applied to the ceramic body, as shown in the enlarged view of FIG. 3B, the paste penetrates into the open pores 6 existing in the ceramic body, and when this paste is fired, it works as a so-called anchor effect. Increase the adhesive strength of.

The internal electrode 5 contains C such as Cu and Ni.
A material that easily interdiffuses with the u and Ni alloys is desirable. The firing is performed in a P _O2 atmosphere in which the Cu and Ni alloys are not oxidized,
At that time, the ceramic is also reduced and the performance is deteriorated. Therefore, it is generally described (Journal of Material).
ial Science 10 ('75) 633)
The reduction is prevented by such a method.

[0009]

[Examples] BaTiO ₃ -CaZrO in which Cu was placed in the internal electrode and 5 mol% of MnO ₂ was added as a reduction inhibitor.
50% Ni-50 as a terminal electrode for capacity extraction on the end face of the element body of the ₃ series ceramic multilayer capacitor (internal electrodes are printed on the ceramic green sheet and degreasing is performed on the laminated chip parts). % Cu alloy fine powder (average particle diameter 2.4 μm) is mixed with a commercially available lead borosilicate glass frit in a weight ratio of 54% 7% resin and kneaded to form a Cu-Ni alloy paste. Then, it was fired in a H ₂ / N ₂ = 1/100 atmosphere in the heat pattern shown in FIG.

Table 1 shows the electrical properties of the produced ceramic multilayer capacitor. The conventional method is also shown in Table 1, but the capacitors manufactured by the method of the present invention are excellent. Although Table 2 shows the production time, electrical performance, and half-erodibility, it can be seen that the method of the present invention is much better than the conventional method.

[0011]

[Table 1]

[0012]

[Table 2]

[0013]

As described above, according to the present invention, Ni-S
Since the n-plating process can be omitted and the manufacturing process can be simplified, the productivity is extremely improved, and the electrical performance and semi-depletion property are superior to those of the conventional method. Electronic parts can be manufactured.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an electronic ceramic component of the present invention.

FIG. 2 is a diagram showing a relationship between a Ni—Cu component, heat resistance, and a bondability of a half.

FIG. 3 (a) is an electronic ceramic component of the present invention,
(B) is a partially enlarged view thereof.

FIG. 4 is a diagram showing a firing heat pattern in an example of the present invention.

FIG. 5A is an external view of a conventional electronic ceramic component,
(B) is the sectional drawing.

[Explanation of symbols]

 1 Ceramic Body 2 Terminal Electrode 3 Ni Plating 4 Sn Plating 5 Internal Electrode 6 Open Pore

Claims (1)

[Claims] 1. When manufacturing an electronic ceramic component in which a base metal is used as an internal electrode and both electrodes thereof are arranged, an alloy paste containing 40 to 60 wt% Cu-60 to 40 wt% Ni as a main component before firing the component is used. Apply to both ends of the part,
After that, baking of the component and baking of the terminal electrodes are performed at the same time.