JP2588445Y2 - Disc-shaped multilayer capacitor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk-shaped multilayer capacitor having a ring shape or the like suitable for mounting on a commutator for preventing noise of a motor.

[0002]

2. Description of the Related Art A multilayer capacitor suppresses the occurrence of sparks generated during operation of a DC motor, for example, to prevent the generation of noise and to extend the life of a brush.
Used by attaching to the commutator of the motor. As such a multilayer capacitor, a disk-shaped multilayer capacitor formed in a ring shape is used. An example of such a conventional disk-shaped multilayer capacitor is shown in FIGS.

In the conventional three-pole capacitor shown in FIG. 5, an annular internal electrode 3 is formed on an insulating layer 2 constituting a laminated chip 1 as shown in FIG. The electrode lead portion 4 extending from the electrode reaches the circumferential edge of the insulating layer 2. In the laminated chip 1 shown in FIG. 5, several layers of the insulating layer 2 having no internal electrode 3 are laminated, and the insulating layer 2 having the pattern of the internal electrode 3 shown in FIG.
It is formed by laminating an appropriate number of layers while shifting each other, and further laminating several insulating layers 2 having no internal electrode 3 thereunder.

Further, as shown in FIG. 5, external electrodes 5, 5,... Are formed on the outer peripheral surface of the laminated chip 1 at intervals of 120 °. The external electrodes 5, 5,... Are formed on the peripheral surface of the laminated chip 1 by the internal electrodes 3, 3, which are exposed there.
Are electrically connected to the electrode lead-out portions 4. That is, the illustrated disk-shaped multilayer capacitor has a three-pole structure in which three sets of internal electrodes 3, 3,... Are opposed to each other, and therefore, the internal electrodes 3, 3,. Are connected to the external electrodes 5, 5,... Every three layers.

Japanese Utility Model Application Laid-Open No. Sho 62-40817 (Japanese Utility Model Application No. Sho 60-132047) discloses a laminated ceramic capacitor, a varistor, a vibrator, a thermistor, etc., having a plurality of internal electrodes provided inside a laminated chip. In the laminated porcelain electronic component, while forming external electrodes on the outer peripheral surface of the laminated chip,
A plurality of cutouts are formed on the outer peripheral surface of the laminated chip, and the cutouts are used to separate external electrodes from each other.

[0006]

However, the conventional disk-shaped multilayer capacitor shown in FIGS. 5 and 6 has the following problems when forming the external electrodes 5, 5,...
That is, in order to form the external electrodes 5, 5,..., A conductive paste is applied to a predetermined position on the peripheral surface of the laminated chip 1,
This is done by burning it. At this time, in order to enhance the productivity, a method of arranging a plurality of laminated chips 1 in the central axis direction and simultaneously applying a conductive paste to the peripheral surfaces thereof is adopted. However, each laminated chip 1
When the conductive paste is applied to the outer peripheral surface of the laminated chip 1 at the positions where the external electrodes 5, 5,... Are to be formed, the outer shape is a disk shape.
It was necessary to align the angle of the electrode lead-out part 4 of the internal electrode 3. However, even if they are arranged once, there is a problem that an angle shift is apt to occur thereafter, so that the application position of the conductive paste is shifted and the internal electrodes are short-circuited to each other. Furthermore, since the outer peripheral surface of the laminated chip 1 is a cylindrical surface, it has been difficult to uniformly apply an appropriate amount of conductive paste thereto.

In the laminated ceramic electronic component described in Japanese Utility Model Application Laid-Open No. Sho 62-40817, the external electrodes are separated from each other by using a plurality of cutouts formed on the outer peripheral surface of the laminated chip. Is possible. However, when the external electrode is formed on the outer peripheral edge of the porcelain substrate, since the outer peripheral surface is a cylindrical surface, there is still a problem that it is difficult to uniformly apply an appropriate amount of conductive paste.

In view of the above-mentioned problems in the prior art, the present invention can form an external electrode at an accurate position on a laminated chip, and uniformly apply an appropriate amount of conductive paste to the outer peripheral surface of the laminated chip. Accordingly, it is an object of the present invention to provide a disk-shaped multilayer capacitor capable of reliably connecting an internal electrode to an external electrode.

[0009]

That is, in order to achieve the above object, according to the present invention, the insulating layers 11, 11,... And the internal electrodes 12, 12,. The chip 10 is constituted, and the internal electrodes 12, 12... Of the respective poles are formed on the outer peripheral surface of the laminated chip 10;
15 are electrically connected to each other.
.. Are formed, and the internal electrodes 1 of the respective poles are formed on the flat portions 13, 13,.
A disc-shaped multilayer capacitor is provided, in which a part of each of 2, 2,... Is exposed, and external electrodes 15, 15,.

[0010]

In the disk-shaped multilayer capacitor according to the present invention, flat flat portions 13, 13,... Are formed on the outer peripheral surface of a multilayer chip 10 which is a laminate of the insulating layers 11, 11,.
Are formed therein, and the external electrodes 15, 15,... Connected to the internal electrodes 12, 12,... Are formed.
In forming 15 ..., the flat portions 13, 13 ...
The positions at which the external electrodes 15, 15,... Are to be formed on the laminated chip 10 can be easily and accurately aligned, and the state can be stably maintained. Further, in order to form the external electrodes 15, 15,...
Are flat surfaces, not cylindrical surfaces, so that it is easy to apply an appropriate amount of conductive paste on them.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows the internal structure of a three-pole disc-shaped multilayer capacitor according to an embodiment of the present invention, so that the insulating layers 11, 11,.
FIG. In this figure, internal electrodes 12, 12,... Are formed on the surfaces of a plurality of insulating layers 11, 11,. The laminated chip 10
An insulating layer 11 having the internal electrodes 12, 12... Having a pattern as shown in FIG. 11 are shifted by 120 ° as shown in FIG. 1 and laminated by an appropriate number of layers.
It is constituted by laminating several layers of insulating layers 11 having no.

The insulating layer 11 is made of, for example, a dielectric ceramic, and has an annular shape as shown in FIG. Also, on the outer peripheral edge, a linear edge that becomes the flat portion 13, 13,.
° formed at intervals. Here, the flat portion 1
The straight edges 3, 13,... Are formed such that the opening angle θ from the center of the insulating layer 11 is 60 °. The internal electrode 12 has a part of the outer periphery protruding outward to form an electrode lead portion 14. The edge of the electrode lead portion 14 extends to a linear edge that becomes the flat portion 13 of the multilayer chip 10. Therefore, the edge of the electrode lead-out part 14 of the internal electrode 12 is exposed in the flat part 13 of the laminated chip 10.

As shown in FIGS. 3 and 4, external electrodes 15 and 15 are further formed on the flat portion 13 of the laminated chip 10 having the above-described layer structure. Are connected to the flat portions 13, 1 of the laminated chip 10.
In 3..., The exposed internal electrodes 12, 12.
Is electrically connected to the electrode lead-out part 14 of the first electrode. That is, since the disk-shaped multilayer capacitor according to this embodiment has a three-pole structure in which three sets of internal electrodes 12, 12,... Are opposed to each other, as shown in FIG. Are connected to the external electrodes 15 for every three layers.

Such a disk-shaped multilayer capacitor is usually manufactured by the following method. First, a ceramic green sheet in which a ceramic slurry in which dielectric ceramic powder is dispersed in a resin binder is formed in a thin sheet shape is prepared, and a plurality of internal electrode patterns are vertically and horizontally formed on the ceramic green sheet according to the shape of the internal electrodes 12, 12,. Arrange and print.
Thereafter, the ceramic green sheets are stacked such that the ceramic green sheets having no internal electrode pattern and the ceramic green sheets having the internal electrode pattern are stacked in the order described above.

Next, using a mold or the like, the laminated body of the ceramic green sheets is cut into individual chips so as to have a disk shape as shown in FIGS. After that, by firing the cut individual chips, the laminated chip 10 having the above-described insulating layers 11, 11,... And the internal electrodes 12, 12,. Furthermore, this laminated chip 10 is
Polishing is performed as necessary, so that the edges of the electrode lead portions 14, 14,... Of the internal electrodes 12, 12,. After that, the plurality of stacked chips 10 are superposed and arranged in the central axis direction, and their angles are aligned with respect to the flat portions 13, 13,. And the flat part 1
By applying a conductive paste to 3, 13,... And baking it, a disk-shaped multilayer capacitor as shown in FIG. 3 is completed.

In the above embodiment, the laminated chip 10 has an annular shape. However, the present invention is not limited to the annular shape, and the present invention can be applied to a disk shape having no center hole. I can do it. Although the above embodiment is a three-pole disc-shaped multilayer capacitor, the present invention can be applied to a two-pole or four-pole or more disc-shaped multilayer capacitor.
Further, the flat portion 13 formed on the outer peripheral edge of the insulating layer 11
If the number is equal to or more than the number of poles of the internal electrode, it is not always necessary to form the same number of poles. Also, the opening angle θ of the flat portion 13
(Refer to FIG. 3) is not limited to 60 °, and should be appropriately determined depending on the number of poles, dimensions, shape, and the like of the disc-shaped multilayer capacitor. The flat portion 13 may be formed at the same time as cutting the green sheet laminate into individual chips.

[0017]

As is clear from the above description, according to the disk-shaped multilayer capacitor of the present invention, the flat portions 13, 13
.. To easily and accurately position the external electrodes 15, 15... On the laminated chip 10, and uniformly apply an appropriate amount of conductive paste to the flat portions 13, 13. Can be formed, so that the internal electrodes can be reliably connected to the external electrodes.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a layer structure of a three-pole ring-shaped multilayer capacitor according to an embodiment of the present invention.

FIG. 2 is a plan view showing the shape of an insulating layer constituting the multilayer capacitor and its internal electrodes.

FIG. 3 is a perspective view showing an appearance of the multilayer capacitor.

FIG. 4 shows an internal electrode structure of the multilayer capacitor.
FIG. 3 is an enlarged cross-sectional view taken along line AA of FIG.

FIG. 5 is a perspective view showing an appearance of a conventional ring-shaped multilayer capacitor.

FIG. 6 is a plan view showing the shape of an insulating layer and its internal electrodes constituting the ring-shaped multilayer capacitor of the conventional example.

[Explanation of symbols]

 Reference Signs List 10 laminated chip 11 insulating layer 12 internal electrode 13 flat part 14 electrode lead-out part 15 external electrode

Claims (1)

(57) [Scope of request for utility model registration] An insulating layer (11), (11) ... and a plurality of internal electrodes (12), (12) ... are alternately laminated to form a disc-shaped laminated chip (10). The internal electrode of the pole (1
2), (12)... Are electrically connected to external electrodes (15), (15)... Formed on the outer peripheral surface of the multilayer chip (10), respectively. Internal electrodes (12), (12) on the outer peripheral surface of 10)
, Flat flat portions (13), (13)... Are formed, and one of the internal electrodes (12), (12)... Of each pole is formed on each flat portion (13), (13). Are exposed, and the flat portions (13), (13),.
5) A disk-shaped multilayer capacitor characterized by forming (15).