JPH01218008A - Sealing structure of capacitor - Google Patents

Abstract

PURPOSE:To completely seal an outer casing without producing any deformation which might be formed by tightening, by forcedly inserting a sealant into the non-circular outer casing, which has a projected piece extending from a flat surface portion at its opening end, and stopping the sealant with the protruding piece of the outer casing. CONSTITUTION:A sealant 4 is mounted over an opening part of an outer casing 2 for a capacitor, the sealant having opposing end surfaces of different sizes. The sealant 4 is pressed when mounted on the casing 2 to seal the casing 2 opening part with its repulsive force. A protruding piece 5 extending from a flat surface part of the casing 2 is folded to stop the repulsive force exerted in a direction of an outer end surface of the sealant 4 for stopping the sealant 4 at the casing opening part. Thus, only the flat surface part stops the sealant 4 at the casing 2 opening part. Hereby, no deformation is produced which is might be formed by tightening over an ellipsoidal arcuate portion of the casing, allowing the casing 2 to be completely sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in capacitors, and particularly to a capacitor sealing structure suitable for surface mounting on a printed circuit board.

[Conventional technology]

Conventionally, to surface mount a capacitor on a printed circuit board,
For example, as disclosed in Japanese Utility Model Publication No. 59-3557, it has been proposed that a conventional capacitor is housed in an outer frame and the lead wires are disposed on substantially the same plane as the end surface of the outer frame.

Alternatively, as in the idea described in Japanese Utility Model Publication No. 55-50992, the lead wire led out from the capacitor is bent and the capacitor body is brought into contact with the printed circuit board.

The sealing structure of such a capacitor is such that a sealing body made of an elastic member such as rubber is attached to an outer case, and the open end of the outer case is crimped.

[Problem to be solved by the invention]

However, when a conventional capacitor is housed in an exterior frame, or when the lead wire is bent and the side of the capacitor body is brought into contact with a printed circuit board, the prismatic space inscribed in the capacitor becomes a waste where other electronic components cannot be placed. Therefore, it is difficult to say that it is compatible with recent miniaturization and high-density packaging of electronic devices.

Therefore, it is conceivable to form the end face shape of the outer case into a non-circular shape. However, it is difficult to swage a non-circular exterior case because the curvature of the non-circular exterior case differs locally, and the airtightness of the exterior case may be incomplete. In particular, when crimping an oval outer case, the crimping at the arcuate portion may result in so-called "deflection" and a gap may be formed between the sealing body and the outer case.

If the sealing performance of the outer case is incomplete in this way, not only will the life characteristics in high temperature ranges deteriorate significantly, but also the soldering process will suffer from sudden thermal stress such as glue flow heat.
The sealing body may protrude from the outer case, resulting in a lack of reliability.

An object of the present invention is to realize a capacitor sealing structure that is compatible with surface mounting on a printed circuit board and that improves sealing accuracy.

[Means to solve the problem]

This invention has a pair of opposing plane parts, and
One end face shape is thicker than the other end face shape (the formed sealing body is press-fitted into a non-circular exterior case that has a protruding piece extending from the flat part at the open end, and the protruding piece of the exterior case It is characterized by being moored with one piece.

In addition, in order to moor the sealing body, the protruding piece of the outer case
It is characterized by being swaged.

Furthermore, as another means for anchoring the sealing body, the projecting piece of the outer case is bent at an approximately right angle at the end of the outer case.

[For production]

As shown in FIG. 2, in the capacitor 1 according to the present invention, a sealing body 4 whose opposing end surfaces are formed in different sizes is attached to an opening of an exterior case 2. When the sealing body 4 is attached to the outer case 2, it is compressed and seals the opening of the outer case 2 by its repulsive force. Further, the protruding piece 5 extending from the flat surface of the outer case is bent, suppresses the repulsive force acting in the direction of the outer end surface of the sealing body 4, and locks the sealing body 4 in the opening of the outer case.

Then, at the open end of the exterior case 2, only the flat portion is subjected to processing such as crimping, bending, etc., and the sealing body 4 is anchored thereto. Therefore, the "deflection" formed by crimping the oval arc portion is eliminated, and together with the repulsive force of the sealing body 4, the exterior case 2 is completely sealed.

In addition, in the first method, a pair of opposing flat parts 7 are formed on the exterior case 2 of the capacitor 1.

One of these plane parts ensures stability when the capacitor 1 according to the invention is mounted on a printed circuit board, and the other plane part serves as a suction surface when conveying by means such as suction.

Also, the space occupied by this invention is
There is only a space surrounding the main body and its arcuate portion, which reduces its volume and also significantly reduces its height.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing the first embodiment of the invention;
The figure is an exploded perspective view illustrating the sealing method in the first embodiment. FIG. 3 is a perspective view showing a second embodiment of the invention.

The capacitor element 6 is formed into a non-circular shape by winding electrode foil and electrolytic paper (not shown). Lead wires 3 electrically connected to each electrode foil protrude from the end face of capacitor element 6 and penetrate through sealing body 4 .

Of the end faces of the sealing body 4, one end face facing the capacitor element 6 is formed to be approximately the same size as the opening of the outer case 2, and the opposite end face is formed to be larger than this end face.

As shown in FIG. 2, the capacitor element 6 is attached to the outer case 2 together with the sealing body 4 penetrated by the lead vA3.
will be stored in. This exterior case 2 is made of aluminum or the like, and has a pair of opposing flat parts, and a protruding piece 5 extending from the flat parts at its open end. Further, the outer surface of the exterior case 2 is coated with a heat-resistant synthetic resin such as epoxy, phenol, polyimide, or the like.

Although any method may be used to apply the coating, in this embodiment, the exterior case 2 is made by press working an aluminum plate material coated with epoxy resin in advance.

A protruding piece 5 extending from the flat surface of the opening end of the exterior case 2
As shown in FIG. 1, the sealing body 4 is press-fitted into the opening of the outer case 2 and is crimped to lock the sealing body. The protruding piece 5 can be crimped by a conventional crimping method using a rotating jig, a press jig, or the like.

The lead wire 3 that penetrates the sealing body 4 and protrudes to the outside is bent from the protruding part of the sealing body 4 along the end surface of the sealing body 4, and furthermore, the tip portion is on the same plane as the flat part of the outer case 2. A look at the wiring pattern of the printed circuit board that will be placed and mounted.

Next, a second embodiment of the invention shown in FIG. 3 will be described.

The capacitor element 6 and the outer case 2 are formed in the same manner as in the first embodiment, and the capacitor element 6 and the sealing body 4 are housed in the outer case 2. The exterior case 2 is made of aluminum or the like, and has the same external shape as the first embodiment.
It has a pair of opposing flat parts.

The protruding piece 5 extending from the flat surface of the outer case 2 is bent at a substantially right angle around the opening end when the sealing body 4 is press-fitted into the outer case 2, and engages the sealing body 4 that is about to protrude outside. Stop.

The lead wire 3 protruding from the end surface of the sealing body 4 is bent from its protruding portion along the end surface of the sealing body 4, and is arranged substantially on the same plane as the flat surface of the outer case 2.

In this embodiment, similarly to the first embodiment, there is no need to process a circular arc portion having a curved surface. And outer case 2
The sealing body 4 can be locked by bending the protruding piece 5 extending to the flat part.

Therefore, compared to the first embodiment, processing at the opening of the outer case 2 is easier, and there is no curved part due to caulking of the protruding piece 5, so that the vertical dimension of the capacitor body 1 can be shortened. Can be done.

〔Effect of the invention〕

As described above, the present invention provides a non-circular exterior case that has a pair of opposing flat parts and a protruding piece extending from the flat parts at the opening end. Since the formed sealing body is press-fitted and moored with the protruding piece of the outer case, the sealing body attached to the opening of the outer case is compressed, and its repulsive force causes the outer case to close. Seal the opening.

Moreover, what locks the sealing body at the opening of the outer case is a protruding piece extending from the flat part. In other words, only the protruding pieces are subjected to processing such as crimping or bending.

Therefore, the "deflection" that is created by crimping the arcuate portion of the outer case as in the past is eliminated, and together with the repulsive force of the sealing body, the outer case is completely sealed. and,
Such a high degree of sealing not only prevents the sealant from protruding during sudden thermal stress such as reflow heat during the soldering process, but also improves the lifespan of the capacitor in high-temperature environments.

Further, the means for locking the sealing body can be performed by crimping or bending to seal a normal capacitor. Therefore, the sealing body can be sealed without requiring special processes, jigs, or the like.

Note that one of the flat parts of the outer case ensures stability on the printed circuit board, and the other flat part serves as a suction surface during transportation. Therefore, it is possible to realize a capacitor that can be surface mounted without housing the cosidenser in an exterior frame as in the conventional case.

In addition, since the opening end face of the exterior case is formed into a non-circular shape with a pair of opposing flat parts, the ratio of the height to the rated capacitance of the capacitor can be reduced compared to conventional In addition to allowing capacitors with large capacitance to be mounted on thin electronic devices, the so-called wasted space is reduced, making it possible to support high-density mounting on printed circuit boards.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the first embodiment of the present invention;
The figure is an exploded perspective view illustrating the sealing method in the first embodiment. FIG. 3 is a perspective view showing a second embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Capacitor, 2... Exterior case, 3... Lead wire, 4... Sealing body, 5... Protrusion piece, 6... Capacitor element, 7... Planar part.

Claims (3)

[Claims] (1) A non-circular exterior case that has a pair of opposing flat parts and a protruding piece extending from the flat parts at the opening end, and a seal with one end face larger than the other end face shape. 1. A capacitor sealing structure, characterized in that a capacitor body is press-fitted and moored with a protruding piece of the outer case. (2) The capacitor sealing structure according to claim 1, wherein the protruding piece of the outer case is crimped. (3) The capacitor sealing structure according to claim 1, wherein the protruding piece of the outer case is bent at an approximately right angle at an end of the outer case.