JPH0670937B2 - Composite porcelain capacitor - Google Patents

Description

The present invention relates to a composite porcelain capacitor, and more particularly to a composite porcelain capacitor having a plurality of chip type laminated porcelain capacitors each having an internal electrode and an external electrode stacked with an adhesive. Regarding porcelain capacitors. More specifically, the present invention relates to an improvement of a composite ceramic capacitor in which a metal plate is joined to the external electrodes of each chip type laminated ceramic capacitor so as to conduct the external electrodes.

[Prior Art] A laminated porcelain capacitor is mainly composed of a porcelain dielectric, an internal electrode provided therein, and an external electrode electrically connected to the internal electrode. Conventionally, the following methods (1) to (3) are available as means for increasing the capacity of this laminated ceramic capacitor.

 Large multi-layer.

 High dielectric constant.

 Stacking of multiple chip type multilayer ceramic capacitors.

Conventionally, in order to stack the chip type laminated ceramic capacitors, as shown in FIGS. 2 (a) and 2 (b), the adhesive 2 is interposed between the chip type laminated ceramic capacitors 1A, 1B, 1C and bonded. Then, the external electrodes 4A, 4B of the obtained joined body 3
4C A metal plate that conducts the same is soldered to the external electrode using high-temperature solder having a soldering temperature of 290 ° C or higher. That is, since the composite porcelain capacitors obtained by stacking are usually mounted on the substrate with commonly used eutectic solder (usually 230 ° C), the metal plate is soldered with high temperature solder having a temperature higher than that of the eutectic solder. Attached.

Among the above-mentioned conventional techniques, the large-scale multi-layering has a drawback in that the multi-layering is technically difficult and thus the yield is reduced. Further, the high induction rate has not been practically developed, and a product having sufficient performance has not been provided.

By stacking a plurality of chip type laminated ceramic capacitors, it is possible to increase the capacity without causing the above-mentioned inconvenience.

[Problem to be Solved by the Invention] However, in the method of (1), a metal plate that conducts the external electrodes is soldered to the external electrodes with high-temperature solder.
In addition to the complicated soldering work, the thermal shock at the time of soldering is large, and the resulting composite ceramic capacitor is liable to cause initial failure or product failure. Also,
Due to this high-temperature solder, the external electrodes of each chip-type laminated ceramic capacitor must be made of a material that has excellent heat resistance of high-temperature solder, as well as solder wettability and corrosion resistance. For this reason, it is necessary to perform Ni / Sn two-layer plating or to use expensive materials such as Pd and Pt for the external electrodes, which increases the manufacturing cost due to an increase in manufacturing processes and high-priced manufacturing raw materials. There were also drawbacks.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a composite ceramic capacitor having a high capacity and a high withstand voltage, which is excellent in various characteristics and which is easily and inexpensively manufactured. .

[Means for Solving the Problems] The composite porcelain capacitor of the present invention is a composite porcelain capacitor in which a plurality of chip type laminated porcelain capacitors having internal electrodes and external electrodes are stacked with an adhesive,
A composite porcelain capacitor in which a metal plate is joined to the external electrodes so that the external electrodes of each chip type laminated porcelain capacitor are electrically connected to each other, the external electrodes being made of thermosetting conductive synthetic resin, It is characterized in that the metal plate and the external electrode are joined by a hardening treatment of a resin.

The present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the composite ceramic capacitor of the present invention, and FIGS. 2 (a) to (d) are sectional views showing an example of the manufacturing procedure of the composite ceramic capacitor of the present invention.

As shown in the figure, the composite porcelain capacitor 10 of the present embodiment has a plurality of element bodies (dielectrics) 1 (1A to 1E) of a chip type laminated porcelain capacitor having internal electrodes (not shown) and external electrodes 4 (first). (5 in FIG. 1), the external electrodes 4 are formed on the stacked ones with the adhesive 2 interposed therebetween,
The external electrode 4 is made of a thermosetting conductive synthetic resin, and a metal plate (for example,
The ribbon lead) 5 is joined to the external electrode 4 by the curing treatment of the thermosetting conductive synthetic resin of the external electrode 4.

In the present invention, as the element body 1, the adhesive 2, and the metal plate 5 of the chip type laminated ceramic capacitor, the same materials as those of the conventional one can be used.

The thermosetting conductive synthetic resin used for forming the external electrodes 4 and joining the metal plates 5 is not particularly limited, but preferably has high conductivity and is cured at a relatively low temperature of 100 to 250 ° C. However, it is preferable that the solder does not deteriorate in the normal soldering process (about 230 ° C.).

As such a thermosetting conductive synthetic resin, a phenol-based resin, a xylene-based resin, a urethane-based resin, or the like can be used.

In order to manufacture the composite porcelain capacitor of the present invention, first, the element bodies 1 (1A to 1C) of a plurality of chip type laminated porcelain capacitors are laminated and adhered via the adhesive 2 (FIG. 2 (a)), and the obtained A thermosetting conductive synthetic resin is attached to the bonded body 3 (FIG. 2B), and the metal plate 5 is brought into contact with the thermosetting conductive synthetic resin external electrode 4 (see FIG. 2C). )), The synthetic resin is heat-treated at a curing temperature (100 to 250 ° C.) for about 30 minutes to be cured to simultaneously form the external electrode 4 and bond the metal plate 5 (FIG. 2 (d)). .

[Operation] In the composite porcelain capacitor of the present invention, the metal plate joined to conduct the external electrodes of each chip type laminated porcelain capacitor is not soldered, but the thermosetting conductive synthetic resin of the external electrode is cured. It is joined by processing. Therefore, the following operational effects are achieved.

It suffices to carry out thermosetting treatment at a temperature much lower than the melting point of high-temperature solder, and thermal shock is reduced in the manufacturing process.
Therefore, it is possible to prevent performance deterioration and defective product generation (reduction in yield) due to thermal shock.

Since high-temperature solder is not used, the work of adhering metal plates is easy and the manufacturing can be automated.

Since the external electrodes can be formed and the metal plates can be joined at the same time, the number of manufacturing steps can be reduced, the manufacturing efficiency and work efficiency can be improved, mass production can be performed, and the product cost can be reduced.

[Examples] Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Example 1 A composite ceramic capacitor 10 of the present invention shown in FIG. 1 was manufactured according to the procedure shown in FIG.

That is, the element body 1 of the chip-type laminated ceramic capacitor
Stacked and glued. The following were used as the adhesive 2, the thermosetting conductive synthetic resin and the metal plate 5 that form the external electrode 4. Further, the thermosetting conductive synthetic resin was cured at 150 ° C. for 30 minutes.

Element of chip type laminated porcelain capacitor: Mitsubishi Mining Cement Co., Ltd. "EIA code 2220 type (5.7mm x 5.0mm)" Characteristics: Rated voltage 25V, capacitance 4.7μF Adhesive: Shikoku Chemicals Co., Ltd. Ultradyne # 5111 W-5 Thermosetting Conductive Synthetic Resin: Hokuriku Paint Co., Ltd. "Thermosetting Conductive Paste H9119" (cures by drying at 100 to 150 ° C. Deteriorates at 400 ° C but withstands normal solder) Metal plate: tin-plated copper plate Various properties of the obtained composite ceramic capacitor were examined according to the following methods, and the results are shown in Table 1.

The measurement was performed on 20 samples (however, 100 initial defects). In Table 1, MAX is the maximum value, MIN is the minimum value, and σn-1 is the standard deviation.

The capacitance (μF) and dielectric loss tangent (%) were measured at 1kHz and 1V.

Insulation resistance (Ω) Indicates the value 30 seconds after applying DC 25V.

DC breakdown voltage (V) Indicates the voltage at which dielectric breakdown occurred when a DC voltage was applied at a boosting rate of 70 V / sec.

Initial failure Number of samples destroyed when a voltage of 2.5 times the rated voltage was applied (100
(In pieces).

Comparative Example 1 A composite porcelain capacitor was manufactured in the same manner as in Example 1 except that a metal plate was joined to the one obtained by joining five chip type laminated porcelain capacitors with an adhesive and using high temperature solder. The results are shown in Table 1.

From Table 1, it is clear that the composite ceramic capacitor of the present invention has improved initial failure because it avoids thermal shock due to soldering.

[Effects of the Invention] As described in detail above, according to the composite ceramic capacitor of the present invention, it is a composite ceramic capacitor having high capacity, high withstand voltage, excellent various characteristics, and high reliability, and can be manufactured easily and at low cost. There is provided a composite porcelain capacitor capable of

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the composite ceramic capacitor of the present invention, and FIG. 2 is a sectional view showing an example of a manufacturing procedure of the composite ceramic capacitor of the present invention. 1 ... Element type chip dielectric ceramic capacitor (dielectric), 2 ... Adhesive, 4 ... External electrode, 5 ... Metal plate, 10 ... Composite ceramic capacitor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Tanidokoro 2270 Yokose, Yokose-cho, Chichibu-gun, Saitama Sanryo Mining Cement Co., Ltd. Ceramics Research Laboratory (72) Inventor ▲ Koichiro Yoshimoto Yokose-cho, Chichibu-gun, Saitama 2270 Yokose, Sanritsu Mining & Cement Co., Ltd. Ceramics Research Laboratory

Claims (1)

[Claims] 1. A composite porcelain capacitor in which a plurality of chip type laminated porcelain capacitors each having an internal electrode and an external electrode are stacked via an adhesive, and a metal is formed so that the external electrodes of each chip type laminated porcelain capacitor are electrically connected. A composite porcelain capacitor having a plate joined to the external electrode, wherein the external electrode is made of thermosetting conductive synthetic resin, and the metal plate and the external electrode are joined by a curing treatment of the resin. A composite porcelain capacitor characterized by.