JPH1116763A - Porcelain capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a lead wire to be easily and efficiently connected to the electrode of a porcelain capacitor and to be protected against disconnection in use by a method, wherein the upper and lower surface of a circular porcelain capacitor except its periphery are recessed, and a projection is provided to the centers of the upper and lower surface respectively. SOLUTION: A circular porcelain capacitor 10 is provided with a dam-like part 11 and a recess 12 at its periphery and center respectively. A projection 13 nearly as high as the dam-like part 11 is provided to the center of the recess 12. An electrode is formed on the upper and lower surface of the porcelain capacitor base 10 respectively. Moreover, the electrodes are preferably formed through an electroless plating method. Then, the electrode attached to an unwanted part is removed by a grinder or the like, and a lead wire is bonded to the projection 13 with solder or the like. By this setup, a lead wire bonding operation can be carried out easily to improve the manufacture of a porcelain capacitor in efficiency, and the lead wire can be protected against disconnection in use.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk-shaped porcelain capacitor used for general electric equipment and electronic equipment.
In particular, the present invention relates to a porcelain capacitor which has a large withstand voltage and is easy to manufacture.

[0002]

2. Description of the Related Art In recent years, electronic devices and the like have been required to have high performance, miniaturization, and thinning, and accordingly, electronic components used in these devices have also been reduced in size, thickness, performance, and quality. Has been requested. The same applies to a disk-shaped porcelain capacitor. The size and thickness of the capacitor are increased by increasing the dielectric constant of the dielectric material used. However, downsizing reduces the electrode area,
Even if a dielectric material having a high dielectric constant is used, if the distance between the electrodes is large, the capacitance value as a capacitor will be low. Therefore, in order to increase the height, a disk having a concave central portion and an electrode formed on the concave portion is manufactured and sold. However, if the distance between the electrodes is simply reduced, a capacitor to which a high voltage is applied may cause insulation breakdown between the electrodes, and may not be used as a capacitor. In order to prevent this, a capacitor has been developed in which the boundary between the embankment-shaped portion and the recessed portion of the capacitor is not vertical but is provided with a constant radius so that electric field concentration does not occur. Kaihei 3-48217).

[0003]

However, in the case of the concave shape at the center as described above, since it is necessary to connect the lead wire to the concave portion, the work of connecting the electrodes is difficult, the efficiency is low, and the lead is poor. Since the lines can be bonded only at points, there is a problem that the bonding strength is low and the wires come off during use. This is the same for the case where R is provided on the surface where the convex portion and the concave portion contact.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gist of the present invention is that the upper and lower surfaces of a disk-shaped porcelain capacitor except for a part thereof are concave. And a convex portion is provided at the center thereof. That is, the acquisition capacity is secured by making most of the upper and lower surfaces concave, and the lead wire can be fixed linearly by making the center part convex. In the present invention, the boundary between the bank and the concave and the boundary between the convex and the concave can have a constant radius.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below by describing a manufacturing method. The dielectric substance for general capacitors can be used for the base of the ceramic capacitor of the present invention. For example, perovskites such as barium titanate and lead titanate are used. The electrode material used in the present invention is required to have good adhesiveness to a dielectric substance which is a body of a capacitor among conductive materials, and good wettability to a lead wire. Examples of the electrode forming method include a method of baking a noble metal such as gold and a method of plating copper and nickel. Also, the electrode need not be a single layer, but may be a plurality of layers. As the lead wire, a copper wire, a Dumet wire, or the like can be used according to the usage environment of the capacitor.

The porcelain capacitor according to the present invention is manufactured according to the following procedure. (1) Prepare raw materials. (2) The prepared raw material is dried and calcined. (3) The calcined raw material is put into a press mold and molded. In this case, it is also possible to mold the raw material without performing calcination. (4) Main firing. (5) Form electrodes on the upper and lower surfaces of the fired substrate.

In the present invention, it is desirable that the electrodes are formed by an electroless plating method. This is because it is difficult to form a uniform electrode over the entire concave portion of the base by a printing method generally used for forming an electrode. (6) The electrode attached to the outer side wall is removed. According to the electroless plating method, an electrode is formed on the entire device, and the electrode attached to an unnecessary portion is removed by a grinder or the like. (7) A lead wire is bonded to the projection using solder or the like.

At this time, the lead wires can be bonded in a state of being parallel to each other with a dielectric material interposed therebetween, or can be bonded in a state of crossing each other.

[0009]

According to the porcelain capacitor of the present invention, a convex portion is provided at the center of the capacitor base, an electrode is formed on the upper surface, and the electrode and the lead wire are bonded to each other. And the lead wire does not come off during use.

[Brief description of the drawings]

FIG. 1 is a perspective view of a porcelain capacitor of the present invention.

FIG. 2 is a conceptual diagram of a ceramic capacitor of the present invention in which a lead wire is connected.

FIG. 3 is a sectional view of FIG. 2; DESCRIPTION OF SYMBOLS 10 Porcelain capacitor 11 Embankment part 12 Concave part 13 Convex part 14 Electrode 15 Lead wire

Claims (1)

[Claims] 1. A disk-shaped porcelain capacitor (10) having a dam-shaped portion (11) in a peripheral portion and a concave portion (12) in a central portion, wherein a dam-shaped portion is formed in the center of the concave portion. A porcelain capacitor characterized by comprising convex portions (13) having substantially the same height.