JPH0349388Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a multilayer capacitor with cap terminals in which cap-shaped terminals are fitted into external electrodes provided at both ends of the multilayer capacitor.

[Conventional technology]

As shown in FIG. 5, the multilayer capacitor 1 includes ceramic sheets 6, 6, . . . on which internal electrodes 7, 7, .
Several layers are laminated, and external electrodes 2, 2 are provided at both ends so as to be electrically conductive to two sets of internal electrodes 7, 7, . . . , respectively. Since this capacitor 1 has the above-described 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 1 via terminals made of metal caps 3, 3. That is, a metal cap 3 with lead wires 5, 5 attached to one closed end surface,
3 is fitted into external electrodes 2, 2 provided at both ends of the multilayer capacitor 1, and lead wires 5, 5 at both ends are arranged on the same straight line.

[Problem that the invention attempts to solve]

However, the multilayer capacitor 1 is small, only a few millimeters long, and is mainly made of porcelain. Furthermore, while the end surfaces of the external electrodes 2, 2 are usually square, the caps 3, 3 fitted therein are circular. For this reason, it is difficult to form a good fitted state between the caps 3, 3 and the external electrodes 2, 2.

For example, if caps 3, 3 and external electrodes 2, 2
Even if the predetermined fitting dimensions are accurately formed between the caps 3, 3 and the external electrodes 2, 2 in the fitted state, the conventional caps 3, 3 with smooth inner circumferential surfaces are Contact is made between external electrodes 2 and 4 of 2.
Only the corner portions 2a, 2a. Therefore, even under the most ideal conditions, the mechanical fit and electrical connection between the caps 3, 3 and the external electrodes 2, 2 are not necessarily sufficient.

Furthermore, the caps 3, 3 and the external electrodes 2, 2 that are actually fitted into each other have some degree of variation in their fitting dimensions due to shrinkage during firing, distortion during processing, and the like. Particularly when this variation is large, as shown in FIGS. 6 and 7, some corner portions 2a of the external electrodes 2, 2 may not come into contact with the inner circumferential surface of the cap 13 during fitting. In such a mated state, the caps 3 and 3 can of course be
Even if the solder plating applied to the inner peripheral surface of the cap is melted and the caps 3, 3 and the external electrodes 2, 2 are soldered,
High soldering strength and reliable electrical connection cannot be obtained.

Further, the fitting between the external electrodes 2, 2 and the caps 3, 3 is usually carried out using a parts feeder or the like.
A means is taken for automatically fitting the multilayer capacitor 1 while adjusting the posture of the multilayer capacitor 1. However, with such means, it is difficult to always fit the caps 3, 3 and the external electrodes 2, 2 together reliably and in the correct posture. For example, due to variations in fitting dimensions between the external electrodes 2, 2 and caps 3, 3, or deviations in relative positions during fitting, these may be misaligned or fitted diagonally, etc. It is often mated in a posture.

This idea was made with the aim of solving the above-mentioned problems with conventional multilayer capacitors with cap terminals. The present invention provides a multilayer capacitor.

[Means to solve the problem]

The structure of this device will be explained with reference to the reference numerals shown in FIGS. 1 to 6. It has a cap terminal with square external electrodes 12, 12 at both ends of a multilayer capacitor 11 fitted into a metal cap 13 with a circular end face. In the multilayer capacitor, protrusions 19, 19, . The external electrode 12 of the multilayer capacitor 11 is fitted into the cap 13 so that the corner 12a of the external electrode 12 is sandwiched.

[Effect]

In this multilayer capacitor with a cap terminal, protrusions 19, 19, . . . formed on the inner peripheral side of the cap 13...
Between the corners 12a, 12 of the external electrodes 12, 12
a... is held, but these protrusions 19, 19...
The number of corners of the external electrodes 12, 12, that is, the corner portions 12a, 1
Since there are integral multiples of the number of 2a..., the square external electrode 1
2 and 12 are always fitted and held in the correct posture.

Also, during the fitting process, the corner portion 12 of the external terminal 12 tends to fit tightly into the inner peripheral surface of the cap 13.
On the a side, the protrusions 19, 19, . . . are crushed and deformed to some extent in response to the external force received from the external electrode 12. Therefore, the cap 13 and the external electrode 12
Even if there are variations in the fitting dimensions, these are absorbed and all corners 12a of the external electrode 12,
12a easily come into uniform contact with the inner peripheral surface of the cap 13.

Furthermore, as shown in FIG.
The inner circumferential surface of 3 hits the corner 12a of the external electrode 12, and the protrusions 19, 19, . . . contact the side surfaces of the external electrodes 12, 12 on both sides of the corner 12a. Therefore, a wide contact area is formed.

〔Example〕

Next, referring to FIGS. 1 to 4, an embodiment of this invention will be described.
is a circular metal member, and its inner diameter is set to be approximately equal to the diagonal length of the external electrode 12 of the multilayer capacitor 11 to be fitted. In the illustrated case, one end surface 13b of the closed cap 13
A lead wire 15 is attached to the side by means of welding or the like.

Sixteen protrusions 19, 19, . . . projecting from the outer circumferential surface to the inner circumferential surface are provided at regular intervals in the circumferential direction on the circumferential surface of the cap 13 by rolling, drawing, etc. There is. The illustrated projections 19, 19, . . . are oval shapes that are elongated in the depth direction of the cap 13, and all have substantially the same shape.

Such a cap 13 changes from the state shown in FIG. 1 to the state shown in FIG.
is fitted from the open end 13a side. At this time, the corner portions 12a of the external electrodes 12 fit between the protrusions 19, 19, . . . to guide their mutual positions. As a result, as shown in FIGS. 2 and 3, the projections 19, 19, . . .
External electrodes 12 on both sides of 2a...
contact the side of the

Due to these effects, the cap 13 and the external electrode 1
2 and 12, and the contact area between the cap 13 and the external electrodes 12, 12.
9, 19, . . . are desirably long in the depth direction of the cap 13, as shown in the figure.

It is preferable to use metal such as iron or brass for the cap 13, and to apply solder plating 18 to the circumferential surface of the cap 13 in advance. Thereby, after the cap 13 is fitted into the multilayer capacitor 11, the cap 13 can be soldered to the external electrode 12 by simply applying heat. The cap 13 and the external electrode 12 may be fixed by means other than soldering, such as adhesion using a conductive adhesive.

In addition, in FIG. 4, 14 is the cap 13.
and an insulating paint applied to the multilayer capacitor 11 during this period. In addition, the illustrated cap 13 includes:
A lead wire 15 is provided, but the cap 13
When the lead wire 15 is directly soldered to a conductor on a circuit board and mounted on the same board, this lead wire 15 is not attached.

[Effect of idea]

As explained above, according to this invention, even if there is a shift in the relative position between the rectangular external electrode 12 and the cap 13, or there is some variation in the fitting dimensions, the cap 13 will always be in the correct posture. It will fit securely. Furthermore, all the corner portions 12a, 12a, . It will be done. Particularly, when the solder plating 18 applied to the inner peripheral surface of the cap 13 is melted in this state and the cap 13 and the external electrode 12 are soldered, high soldering strength and good electrical connection can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a multilayer capacitor with a cap terminal showing an embodiment of this invention, FIG. 2 is an end view showing the fitted state of the cap and the external electrode of the multilayer capacitor in the same embodiment, and FIG. The figure shows the second
Figure 4 is an enlarged view of part A in the figure, Figure 4 is a longitudinal cross-sectional side view of the cap fitted to the external electrode of the multilayer capacitor, and Figure 5 is an exploded perspective view of a partially cutout showing a conventional example of a multilayer capacitor with a cap terminal. 6 and 7 are schematic end views showing examples of the fitted state of the cap and the external electrode in the conventional example. 11... Multilayer capacitor, 12... External electrode,
13... Cap, 18... Solder plating, 19...
…protrusion.

Claims (1)

[Claims for Utility Model Registration] (1) Square external electrodes 12, 12 at both ends of the multilayer capacitor 11 on a metal cap 13 with a circular end face.
In a multilayer capacitor with a cap terminal fitted with a multilayer capacitor, protrusions 19, 19, . A multilayer capacitor with a cap terminal, characterized in that an external electrode 12 of a multilayer capacitor 11 is fitted into a cap 13 so that a corner 12a of the external electrode 12 of the multilayer capacitor 11 is sandwiched between the cap terminals 19, 19. (2) The multilayer capacitor with cap terminals according to claim 1, in which the protrusions 19, 19, . . . have an elongated shape in the depth direction of the cap 13. (3) The cap 13 has solder plating 18 on its circumferential surface.
A multilayer capacitor with a cap terminal according to claim 1 or 2 of the utility model registration claim.