JPH0246027Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention was developed to improve electrolytic capacitors.
In particular, the present invention relates to a terminal structure that allows surface mounting of electrolytic capacitors in which external connection leads are led in the same direction.

[Conventional technology]

In general electrolytic capacitors, a capacitor element formed by winding electrode foil and electrolytic paper is housed in a bottomed cylindrical outer case made of aluminum or the like, and the opening of the outer case is sealed with a sealing material made of elastic rubber or the like. It is configured by installing.

Conventionally, a method for making an electrolytic capacitor having such a structure leadless and making it compatible with surface mounting on a board is described in Japanese Patent Application Laid-Open No. 59-211213.
There is also something like the one shown in Figure 2. That is, the insulating plate 14 is arranged on the outer end surface of the electrolytic capacitor 1, the leads 12 are made to protrude to the back surface of the insulating plate 14 through the insertion hole 16 formed in the center of the insulating plate 14, and are inserted along the back surface of the insulating plate 14. The insulating plate 14 is bent to form a substantially flat surface on the back surface of the insulating plate 14. As a result, the electrolytic capacitor 1 can stand on its own.

Such an electrolytic capacitor 1 can be surface mounted on a substrate without changing the structure of a normal electrolytic capacitor.

[Problem to be solved]

However, in the conventional leadless electrolytic capacitor 1, only the leads 12 led from the electrolytic capacitor 1 come into contact with the conductor portion 13 of the substrate 17, as shown in FIG. Therefore, the electrolytic capacitor 1 and the conductor portion 1 of the substrate 17
The contact area with 3 must become narrower. Alternatively, it is possible to form the tips of the leads 12 into a flat shape, but it is still difficult to provide a sufficient contact area. Therefore, the lead 12 and the board 1
The portion where the conductor portion 7 contacts the conductor portion 13 is narrow, making it difficult to obtain a highly reliable connection state.

In addition, when electronic components are generally surface-mounted by reflow soldering, the portion where the leads 12 and the conductor portion 13 of the board 17 are connected by the solder 15 is the end face of the lead 12, as shown in FIG. Often. That is, the molten solder 15
Since the back surface of the lead 12 is in contact with the substrate 17, the bonding material hardly penetrates into the back surface of the lead 12 and is fused so as to creep up onto the end surface of the lead 12. Therefore, if the area of the end face of the lead 12 is small, the electrical connection between the conductor portion 13 of the substrate 17 and the lead 12 may be insufficient. Also,
Depending on the state of the soldering, the leads 12 may separate from the surface of the solder 15 after surface mounting due to vibration of the board 17 or swelling of the sealing body 6 due to an increase in the internal pressure of the electrolytic capacitor 1 due to a rise in temperature. There was a risk that it would be lost.

The purpose of this invention is to enable surface mounting on a substrate without changing the structure of conventional electrolytic capacitors, and to achieve good electrical connection by soldering.

[Means to solve problems]

This idea consists of an electrolytic capacitor with external connection leads led in the same direction, and a heat-resistant synthetic resin exterior material with a through hole in the center with an inner diameter that is the same as or slightly larger than the electrolytic capacitor's outer diameter. The exterior material is fitted to the lower side of the electrolytic capacitor so that the end surface of the electrolytic capacitor and the back surface of the exterior material form a substantially flat surface, and the tip of the lead of the electrolytic capacitor is fitted onto the back surface of the exterior material. It is characterized by being sequentially bent from the top along the outer surface and top surface.

[Effect]

An integral synthetic resin exterior material is placed on the lower side of the electrolytic capacitor, and the leads led from the electrolytic capacitor anchor this exterior material, allowing the electrolytic capacitor to stand on its own.

Further, since the leads are closely attached to the back surface of the exterior material to form a substantially flat surface, the electrolytic capacitor obtained by this invention can be surface mounted.

〔Example〕

Examples of this invention will be described below with reference to the drawings.

FIG. 1 is a partially sectional view showing an embodiment of this invention. FIG. 3 is a perspective view showing the external shape of the exterior material used in the example and the state in which an electrolytic capacitor is attached.

In FIG. 1, a normal electrolytic capacitor 1 is
A capacitor element 2 formed by winding an electrode foil 3 and an electrolytic paper 4 is housed in a bottomed cylindrical outer case 5 made of aluminum or the like, and a sealing body made of elastic rubber or the like is placed in the opening of the outer case 5. 6 is installed. Further, the lead 8 is electrically connected to the electrode foil 3, guided from the capacitor element 1, and protrudes to the outside through the sealing body 6. Further, the outer surface of the outer case 5 is covered with a sleeve 7 made of synthetic resin such as vinyl chloride.

On the lower surface of such an electrolytic capacitor 1, an exterior material 9 as shown in FIG. 3 is arranged. This exterior material 9 is made of synthetic resin and has a circular through hole 10 in the center through which the electrolytic capacitor 1 can be inserted. The through hole 10 has an inner diameter that is approximately the same as the outer diameter of the electrolytic capacitor 1 .

This exterior material 9 includes a continuous band 11 made of synthetic resin.
A circular through hole 10 is formed on the center line of the hole 10, and adjacent through holes 10 are cut at positions equidistant from each other.

Lead 8 led from the end face of electrolytic capacitor 1
is sequentially bent along the back, side, and top surfaces of the exterior casing 9 to connect the exterior casing 9 to the electrolytic capacitor 1.
It is moored at.

Note that the exterior material 9 used in the embodiment of this invention does not have to be a single piece. That is, as shown in FIG. 3, the electrolytic capacitors 1 are sequentially supplied to the continuous band 11 of the plurality of exterior materials 9 formed continuously, and the leads 8 are sequentially supplied from the back surface to the side surface and the top surface of the exterior material 9. It may be bent and the electrolytic capacitor 1 may be fixed. With this configuration, each individual electrolytic capacitor 1 is continuously supplied and is individually separated in the process of mounting it on a board. Therefore, continuous production of the electrolytic capacitor 1 becomes easy, and at the same time,
It will also be easier to automate mounting on the board.

Furthermore, when the tip of the lead 8 led from the electrolytic capacitor 1 is brought into contact with the back surface of the exterior material 9, it may be processed into a flat shape in advance. In this case, since the ground area between the wiring on the board and the leads 8 is increased, a good connection state can be expected, and reliability can be easily improved.

[Effect of idea]

As mentioned above, this idea consists of an electrolytic capacitor whose external connection leads are led in the same direction, and a heat-resistant capacitor with a through hole in the center that has an inner diameter that is the same as or slightly larger than the outer diameter of the electrolytic capacitor. The exterior material is fitted to the lower side of the electrolytic capacitor so that the end surface of the electrolytic capacitor and the back surface of the exterior material form a substantially flat surface. is characterized in that it is sequentially bent from the back of the exterior material to the outside and top surfaces, allowing the electrolytic capacitor to stand on its own, and the leads leading from the electrolytic capacitor are placed on the back of the insulating board. It can be surface-mounted on a substrate with almost no changes to the conventional structure.

Moreover, since the leads are sequentially bent along the back surface of the opening, the outer surface, and the top surface of the exterior material, the leads are also arranged on the side surfaces of the insulating plate. Therefore, when the electrolytic capacitor obtained by this invention is surface-mounted by reflow soldering, the molten solder creeps up and adheres to the side of the insulating plate, that is, to the leads, creating a reliable electrical connection. It can be realized.

As described above, this invention is a useful invention that enables surface mounting on a substrate without changing the structure of a conventional electrolytic capacitor.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view showing an embodiment of this invention, Fig. 2 is a sectional view showing the structure of a conventional leadless electrolytic capacitor, and Fig. 3 is a sectional view of the exterior material used in this invention. FIG. 2 is a perspective view showing the external shape and the state in which the electrolytic capacitor is housed. 1... Electrolytic capacitor, 2... Capacitor element, 3... Electrode foil, 4... Electrolytic paper, 5... Exterior case, 6... Sealing body, 7... Sleeve, 8, 12
... Lead, 9 ... Exterior material, 10 ... Through hole, 11
...Continuous band, 13...Conductor portion, 14...Insulating plate, 15...Solder, 16...Through hole, 17...Substrate.

Claims (1)

[Scope of utility model registration request] It consists of an electrolytic capacitor with external connection leads led in the same direction, and a heat-resistant synthetic resin exterior material that has a through hole in the center with an inner diameter that is the same as or slightly larger than the electrolytic capacitor's outer diameter. The exterior material is fitted to the lower side of the electrolytic capacitor so that the end surface of the electrolytic capacitor and the back surface of the exterior material form a substantially flat surface. An electrolytic capacitor characterized by sequential bending along the top surface.