JPH03272122A - Compound ceramic capacitor - Google Patents

Abstract

PURPOSE:To enable the title compound ceramic capacitor having enhanced characteristics such as high capacity and high withstanding voltage to be manufactured easily at low cost by a method wherein sheets are junctioned with outer electrodes making them mutually conductive through the intermediary of thermosetting conductive synthetic resin. CONSTITUTION:Multiple chip type laminated ceramic capacitors 1(1A-1C) are lamination-bonded through the intermediary of a bonding agent 2. Next, metallic sheets 6 are abutted with one another through the intermediary of a thermosetting conductive synthetic resin 5 to make the outer electrodes 4(4A-4C) of the formed compound body 3 conductive so that the metallic sheets 6 may be electrically heat- treated at the setting temperature (100-250 deg.C) of the resin 5 for 30 minutes to be junctioned with the outer electrodes 4. Through these procedures, the metallic sheets 6 can be junctioned with the electrodes 4 through the intermediary of the resin 5 without resorting to the soldering step to absorb the thermal shock thereby enabling the deterioration in performance and the development of defective products (decrease in the yield) due to the thermal shock to be avoided. On the other hand, the bonding work of the metallic sheets 6 can be facilitated without using a high temperature solder simultaneously enabling the manufacture to be automated while enhancing the characteristics of the title capacitor due to the elimination of the soldering step.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a composite ceramic capacitor, and more particularly to a composite ceramic capacitor in which a plurality of chip-type laminated ceramic capacitors having internal electrodes and external electrodes are stacked together with an adhesive. Regarding magnetic capacitors. More specifically, the present invention relates to an improvement of a composite ceramic capacitor in which a metal plate is bonded to the external electrodes of each chip-type multilayer ceramic capacitor in order to conduct the external electrodes with each other.

[Prior Art] A multilayer ceramic capacitor is mainly composed of a ceramic dielectric, an internal electrode provided inside the dielectric, and an external electrode electrically connected to the internal electrode. Conventionally, the following methods 1 to 2 have been used to increase the capacitance of this multilayer ceramic capacitor.

■Large multilayer.

■ High dielectric constant.

■ Stacking multiple chip-type multilayer ceramic capacitors.

Conventionally, chip-type multilayer ceramic capacitors IA are stacked as shown in FIGS. 2(a) and 2(b).

IB and IC are bonded with adhesive 2 interposed between them, and a metal plate that conducts the external electrodes 4A, 4B, and 40 of the resulting bonded body 3 is soldered using high-temperature solder at a temperature of 290°C or higher. and solder it to the external electrode. That is, the composite ceramic capacitors obtained by stacking are usually mounted on a board with commonly used eutectic solder (usually 230°C), so the metal plates are soldered with high-temperature solder that is higher than the eutectic solder. will be attached.

Among the above-mentioned conventional techniques, large-scale multi-layering (2) has the disadvantage that it leads to a decrease in yield because multi-layering is technically difficult. Further, the development of (2) high dielectric constant has not been developed to be practically satisfactory, and no product with sufficient performance has been provided.

By stacking a plurality of chip-type laminated ceramic capacitors (2), it is possible to increase the capacitance without causing the above-mentioned problems.

[Problems to be Solved by the Invention] However, in the method (2), since the metal plate that connects the external electrodes to each other is soldered to the external electrodes using high-temperature solder,
This soldering process is not only complicated, but also causes a large thermal shock during soldering, which tends to cause initial defects and product defects in the resulting composite ceramic capacitor. Also,
For this high-temperature soldering, the external electrodes of each chip-type multilayer ceramic capacitor must be made of a material that has excellent heat resistance to high-temperature soldering, as well as excellent solder wettability and corrosion resistance. Therefore, the external electrode has 2 of N i /S n
It is necessary to perform layer plating or use expensive materials such as Pd and Pt, and there is also the disadvantage that the manufacturing cost is high due to the increase in manufacturing steps and the use of expensive manufacturing raw materials.

It is an object of the present invention to solve the above-mentioned conventional problems and provide a composite ceramic capacitor with high capacity and high withstand voltage, which has excellent various characteristics and can be easily and inexpensively manufactured. .

[Means for Solving the Problems] A composite ceramic capacitor of the present invention is a composite ceramic capacitor in which a plurality of chip-type laminated ceramic capacitors each having an internal electrode and an external electrode are stacked with an adhesive interposed therebetween.
A composite ceramic capacitor in which a metal plate is bonded to the external electrodes of each chip-type multilayer ceramic capacitor so as to conduct each other, and the metal plate connects the external electrodes via a thermosetting conductive synthetic resin. It is characterized by being joined to.

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

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

As shown, the composite ceramic capacitor 1° of the present invention includes a plurality of chip-type multilayer ceramic capacitors 1 (IA to IE) having internal electrodes (not shown) and external electrodes 4 (4A to 4E) (Fig. (5 pieces) are stacked via adhesive 2, and external electrode 4 of each chip type multilayer ceramic capacitor 1
(4A to 4E) A metal plate (for example, a ribbon lead) 6 is joined to the external electrode 4 via a thermosetting conductive synthetic resin 5 so as to conduct each other.

In the present invention, the chip-type multilayer ceramic capacitor 1, the adhesive 2, and the metal plate 6 may be made of the same materials as conventional ones.

The thermosetting conductive synthetic resin used for joining the metal plates 6 is not particularly limited, but preferably has high conductivity,
It is preferable to use a material that hardens at a relatively low temperature of 100 to 250°C and does not deteriorate during normal soldering processing (about 230°C).

As such thermosetting conductive synthetic resins, phenol-based, xylene-based, urethane-based resins, etc. can be used.

In order to manufacture the composite ceramic capacitor of the present invention, first, a plurality of chip-type multilayer ceramic capacitors 1 (IA to IC) are laminated and bonded via an adhesive 2 (FIG. 2(a')), and the resulting bonded External type FiA4 (4A
The metal plate 6 was brought into contact with the thermosetting conductive synthetic resin 5 so as to conduct the electrical conductivity (Fig. 2(c)), and the heat was heated at the curing temperature of the synthetic resin (100 to 250°C) for 30 minutes. They are bonded by heat treatment to a certain extent (Fig. 2(d)).

[Function] In the composite ceramic capacitor of the present invention, the metal plates that are joined in order to conduct the external electrodes of each chip-type multilayer ceramic capacitor are connected to the external electrodes not by soldering but through a thermosetting conductive synthetic resin. is joined to. Therefore, the following effects are achieved.

■ Heat curing treatment can be performed at a temperature far lower than the melting point of high-temperature solder, reducing thermal shock during the manufacturing process.

Therefore, performance deterioration and generation of defective products (yield decrease) due to thermal shock can be prevented.

■ It does not use high-temperature solder, making it easy to bond metal plates, and automation of manufacturing is also possible.

■ Since there is no soldering process, it is easy to select external electrodes for chip-type multilayer ceramic capacitors. That is, it is possible to use a material optimal for the dielectric of the capacitor as the external electrode material without considering solder wettability, solder corrosion resistance, and solder heat resistance. Therefore, the characteristics of the composite ceramic capacitor can be further improved. Furthermore, plating of the external electrodes to improve solder wettability and solder heat resistance is not required, and the number of manufacturing steps is reduced.

[Example] The present invention will be described in more detail with reference to Examples and Comparative Examples below.

Example 1 A composite ceramic capacitor 10 of the present invention shown in FIG. 1 was manufactured according to the procedure shown in FIG. 2.

That is, five chip-type multilayer ceramic capacitors 1 described below were stacked and bonded. Adhesive 2, thermosetting conductive synthetic resin 5
As the metal plate 6, the following was used. Further, the adhesive IA filling of the metal plate was performed at 150° C. for 30 minutes.

Chip type multilayer porcelain capacitor: Mitsubishi Mining Cement rEIA code 2220 type (5,7mm x 5
:Omm) J characteristics: Rated voltage 25v.

Capacitance 4.7 μF Adhesive: Ultradyne #5111 manufactured by Shikoku Kasei Kogyo Co., Ltd.
W-5 Thermosetting conductive synthetic resin Hokuriku Paint Co., Ltd. Thermosetting conductive paste H9119J (hardens by drying at 100 to 150°C.

It deteriorates at 400°C, but can withstand normal soldering. ) Metal plate: tin plated copper plate The characteristics of the obtained composite ceramic capacitor were investigated according to the following method, and the results are shown in Table 1.

The measurement was performed on 30 samples (100 samples were initially defective). In Table 1, MAX is the maximum value, MI
N is the minimum value, σ. , indicates standard deviation.

Capacity (μF), dielectric loss tangent (%) Measured at 1 kHz, IV.

Insulation resistance (Ω) The value is shown 30 seconds after applying DC25V.

DC breakdown voltage (V) A DC voltage is applied at a boost rate of 70 V/sec, and the voltage at which dielectric breakdown occurs is shown.

Number of samples destroyed when applying a voltage 2.5 times the initial failure rating (
Comparative Example 1 A composite ceramic capacitor was manufactured in the same manner as in Example 1 except that the metal plates were joined by high-temperature solder instead of using thermosetting conductive synthetic resin. The characteristics of the fibers were investigated and the results are shown in Table 1.

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

[Effects of the Invention] As detailed above, the composite ceramic capacitor of the present invention has high capacity, high withstand voltage, excellent characteristics, and high reliability, and can be manufactured easily and at low cost. A composite ceramic capacitor is provided that can be used.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing one embodiment of the composite ceramic capacitor of the present invention, and FIG. 2 is a cross-sectional view showing an example of the manufacturing procedure of the composite ceramic capacitor of the present invention. DESCRIPTION OF SYMBOLS 1... Chip type multilayer ceramic capacitor, 2... Adhesive, 4... External electrode, 5... Thermosetting conductive synthetic resin, 6... Metal plate, 10... Composite ceramic capacitor .

Claims (1)

[Claims] (1) In a composite ceramic capacitor in which multiple chip-type multilayer ceramic capacitors each having an internal electrode and an external electrode are stacked together with an adhesive, a metal plate is connected so that the external electrodes of each chip-type multilayer ceramic capacitor are electrically connected to each other. A composite ceramic capacitor bonded to the external electrode, wherein the metal plate is bonded to the external electrode via a thermosetting conductive synthetic resin.