JPH0410672Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a multilayer capacitor in which lead wires are provided via metal terminals to external electrodes provided at both ends of a multilayer capacitor element.

[Conventional technology]

As shown in Fig. 4, a multilayer capacitor is made by laminating several layers of magnetic sheets 6, 6... on which internal electrodes 7, 7... are printed, and connecting both ends of the magnetic sheets 6, 6... to conduction to two sets of internal electrodes 7, 7..., respectively. External electrodes 2, 2 are provided on the periphery. Since this capacitor has the above-mentioned laminated structure, it usually has a cubic shape.

Conventionally, an attempt has been proposed in which lead wires 5, 5 are drawn out on the same straight line from both ends of the multilayer capacitor via metal terminals 3, 3. That is,
Lead wires 5, 5 are attached to one closed end surface of the cap-shaped terminals 3, 3, and these are fitted into external electrodes 2, 2 provided at both ends of the multilayer capacitor element 1. are arranged on the same straight line.

An insulating coating 4 is applied between the terminals 3 and 3 for the purpose of ensuring insulation, protecting the multilayer magnetic capacitor element 1, fixing the terminals 3 to the capacitor element 1, etc.
is coated.

[Problem that the invention attempts to solve]

However, as a result of prototype production of the above multilayer capacitor by the inventors of the present invention, the following three problems were found.

First, in the capacitor described above, a relatively large gap is formed between the cubic multilayer capacitor element 1 and the circular cap-shaped terminals 3, 3.
The air existing in this gap undergoes rapid thermal expansion when the insulating paint 4 is applied to the multilayer capacitor element 1 and heated.

However, if the open ends of the terminals 3, 3 are blocked by applying the insulating paint 4, the expanded air flows into the molten insulating paint 4, as shown by the arrow in FIG. It breaks through and erupts from its surface.

After the insulating paint 4 has hardened, the traces of the air blown out remain as pores and voids, resulting in a decrease in insulation properties. Further, in the above-mentioned hole, a jet port is located at the terminal 3,
Because there is something that remains as a protrusion on the outside of 3,
This becomes an obstacle when mounting a multilayer magnetic capacitor on a wiring board.

Second, when the open ends of the terminals 3, 3 are closed,
The insulating paint 4 is blocked by the air inside it, and the terminals 3,
3 and the multilayer capacitor element 1 becomes difficult to penetrate. Therefore, the insulating paint 4 is not filled into the gap, ensuring insulation, protecting the multilayer ceramic capacitor element 1, and connecting the terminal 3 to the capacitor element.
The original function of the insulating paint 4, such as the fixation of 3, cannot be fully obtained.

Thirdly, the circular terminals 3, 3 and the rectangular external electrodes 2, 2 are in line contact only at the four corners of the external electrodes 2, 2 when mated, so there is no mechanical or electrical contact between them. It is not always easy to form a good fitted state.
Therefore, if the terminals 3, 3 are simply fitted together or covered with the insulating paint 4, the terminals 3, 3 tend to fall off from the external electrodes 2, 2, and a sufficient electrical connection cannot be obtained.

In order to improve this point, it is effective to solder the terminals 3, 3 to the external electrodes 2, 2 on the inner peripheral side. However, since the terminals 3 and 3 are extremely small with a diameter of only a few millimeters,
The inner circumferential side of the terminals 3, 3 hidden from the outside is connected to the external electrode 2,
It is extremely difficult to solder to 2.

This idea was made in order to solve the above problems, and it does not create holes or voids in the insulating coating, and it also provides insulation between the terminals 3, 3 of the insulating coating and the multilayer capacitor element 1. The paint 4 is sufficiently penetrated, and the terminals 3 and 3 are connected to the outer electrodes 2 and 2 on the inner circumferential side.
The purpose is to provide a multilayer capacitor that is reliably soldered.

[Means to solve the problem]

The structure of this invention will be explained by referring to the reference numerals used in FIGS. Circular metal terminals 13, 13 having openings 20 formed around them are connected to external electrodes 1 provided at both ends of a multilayer capacitor element 11 having a substantially cubic shape.
2, 12, and the terminals 13, 13 are connected to the external electrodes 12, 12 by solder plating applied to their peripheral surfaces.
and further solder the multilayer capacitor element 1 to
1 is covered with an insulating paint 14.

[Effect]

In this multilayer capacitor, terminals 13, 13 are
Since the terminals 13, 13 are soldered to the external electrodes 12, 12 by the solder plating 18, 18 applied to the peripheral surface in advance, the soldering with the external electrodes 12, 12 is ensured on the inner peripheral surface side of the terminals 13, 13. It will be held in

In addition, in a multilayer capacitor, capacitor element 1
1 has an almost cubic shape, whereas the terminals 13, 13 fitted at both ends are circular, so that the terminals 13, 13 and both ends of the capacitor element 11 are connected to each other, as shown in FIG. A large gap is created between the terminals 12, 12. In this case, terminal 1
Even if one of the openings 20, 20... side of terminals 3, 13 is covered with insulating paint 14, the terminal 1
3, 13 and the multilayer capacitor element 11, the air exists in the gap between the multilayer capacitor element 11 and the openings 20, 2 on the other end surface side.
Since the air escapes from the 0... side, the expanded air does not break through the insulating paint 14 and blow out.

〔Example〕

Next, an embodiment of this invention will be described with reference to FIGS. 1 to 3.

First, to explain the embodiment shown in FIGS. 1 and 2, a plurality of ceramic sheets 16, 16... are laminated, and two sets of internal electrodes 17, 17... printed on these sheets are arranged alternately. has been done. Furthermore, the two sets of internal electrodes 1 are placed at both ends of this laminate.
External electrodes 12, 1 conductive to 7, 17, respectively.
2 are provided to constitute the multilayer capacitor element 11.

Ring-shaped terminals 13, 13 are fitted into both ends of the multilayer capacitor element 11, and the inner peripheral sides thereof are soldered to the external electrodes 12, 12 by solder plating 18, 18 applied in advance. Furthermore, an insulating paint 14 is applied between these terminals 13, 13.

On one end surface of the terminals 13, 13, there is a spoke-shaped lead wire attachment part 21 extending radially from the center.
21 is provided, and lead wires 15, 1 are provided in the center of this.
5 is attached by means such as welding. Openings 20, 20, . . . are formed around this central portion. In the case shown, lead wire attachment part 2
1, 21... are four spoke-like objects,
Therefore, the openings 20, 20... lead...15,
It consists of fan-shaped parts placed at 90° intervals around the central part where the number 15 is attached.

The shape of the openings 20, 20, . . . is not limited to the fan shape as described above, and generally, for example, a circular, rectangular, square, triangular, etc. shape is employed.

In the embodiment shown in FIG. 3, in the terminals 13, 13 similar to those used in the above embodiment, a cutting line is placed at one point on the circumference at an angle with respect to the circumferential direction.
9. In this case, terminal 13,1
By using a capacitor 3 that is slightly tighter than the multilayer capacitor element 11, the terminals 13 and 1
3, the terminals 13, 13 can be fitted into the external electrodes 12, 12 without any play. This makes it easier to solder the terminals 13, 13 and the external electrodes 12, 12.

Since the cutting line 19 is provided obliquely with respect to the circumferential direction, the multilayer capacitor element 1
Inconveniences such as the crest of No. 1 getting stuck in will not occur.

[Effect of idea]

As explained above, according to this invention, terminal 1
A multilayer capacitor in which the inner circumferential sides of 3 and 13 are reliably soldered to the external electrodes 12 and 12 is obtained. Furthermore, troubles such as the formation of pores and voids in the insulating paint 14 can be prevented, and the insulating paint 14 can be sufficiently penetrated into the gaps between the terminals 13, 13 and the multilayer capacitor element 11.

As a result, defects such as falling off of the terminals 13, 13, poor electrical connection, or defects due to pores and voids in the insulating paint 14 are reduced, and a high yield is obtained. Also, it is possible to provide a multilayer capacitor with excellent fixing function of the terminals 13, 13.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway exploded perspective view of a multilayer capacitor showing an embodiment of this invention, with insulation paint omitted;
Fig. 2 is a cross-sectional view of the same multilayer capacitor, Fig. 3 is an exploded perspective view of a multilayer capacitor showing another embodiment without the insulating paint, and Fig. 4 is a conventional example of a multilayer capacitor using metal terminals. FIG. DESCRIPTION OF SYMBOLS 11... Multilayer capacitor element, 12... External electrode of multilayer capacitor element, 13... Terminal, 14...
... Insulating paint, 15 ... Lead wire, 18 ... Solder plating, 19 ... Cutting wire, 20 ... Terminal opening,
21...Lead wire attachment part.

Claims (1)

[Claims for Utility Model Registration] 1. A multilayer capacitor having a substantially cubic shape, with lead wires 15, 15 attached to the center of the end face, and circular metal terminals 13, 13 with an opening 20 formed around the lead wires 15, 15. The multilayer capacitor element 11 is provided at both ends of the element 11 and fitted into the external electrodes 12, 12, and the terminals 13, 13 are soldered to the external electrodes 12, 12 by solder plating applied to the peripheral surface of the element 11. Insulating paint 14
A multilayer capacitor using a metal terminal characterized by being covered with a metal terminal. 2. The multilayer capacitor according to claim 1, in which the terminal 13 is provided with a cutting line 19 oblique to the circumferential direction at one location on the circumference.