JPH0262933B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to the improvement of electrolytic capacitors,
In particular, the present invention relates to a terminal structure of an electrolytic capacitor compatible with surface mounting on a substrate.

[Conventional technology]

BACKGROUND ART In recent years, with the automation and higher integration of electronic component mounting processes, there has been a demand for leadless electronic components that can be surface mounted on substrates.

Generally, when an electrolytic capacitor is made leadless, there is a method described in Japanese Patent Laid-Open No. 59-211213 and shown in FIG. 2. That is, an insulating plate 18 is arranged on the end face of the electrolytic capacitor 1, and a lead 20 led from the electrolytic capacitor 1 is connected to the insulating plate 1.
It penetrates the through hole 19 provided in the insulating plate 18 and protrudes from the back surface of the insulating plate 18, and is bent along the back surface of the insulating plate 18.

In such a conventional leadless electrolytic capacitor, since a substantially flat surface is formed on the back surface of the insulating plate 18, surface mounting on the substrate 21 is possible without changing the structure of the normal electrolytic capacitor 1. .

[Problem to be solved]

However, in a leadless electrolytic capacitor having a conventional structure, only the lead 20 led from the main body of the electrolytic capacitor 1 comes into contact with the conductor portion 22 of the substrate 21 . Therefore, the contact area between electrolytic capacitor 1 and conductor portion 22 must become narrow. Alternatively, it is possible to form the tips of the leads 19 into a flat shape, but it has been difficult to provide a sufficient contact area. Therefore, lead 1
9 and the conductor portion 22 of the substrate 21 are narrow, making it difficult to obtain a highly reliable connection.

Further, when electronic components are generally surface mounted by reflow soldering, the end surface of the lead 20 is connected to the conductor portion 22 of the board 21 at the portion where the lead 20 and the conductor portion 22 of the board 21 are connected by the solder 23, as shown in FIG. Often. That is, the melted solder 23 is
Since the back surface of the lead 20 is in contact with the conductor portion 22, it is fused so as to creep up onto the end surface of the lead 20 without almost entering the back surface of the lead 20. Therefore, if the area of the end face of the lead 20 is small, the contact area with the solder 23 will be reduced. Therefore, the electrical connection between the conductor portion 22 of the substrate 21 and the lead 20 was sometimes insufficient. Depending on the state of soldering, the leads 20 may separate from the surface of the solder 23 after surface mounting due to vibration of the board 21 or swelling of the sealing body 6 due to an increase in internal pressure of the electrolytic capacitor 1 body due to temperature rise. There was a fear that I might do it.

Furthermore, since the insulating plate 18 and the main body of the electrolytic capacitor 1 are only connected by mooring by bending the leads 20, the mechanical strength is weak. Therefore, if extra mechanical stress is applied to the insulating plate 18, there is a risk that the insulating plate 18 will separate from the main body of the electrolytic capacitor 1.

An object of the present invention is to realize a leadless electrolytic capacitor that can be surface mounted on a substrate without changing the structure of a conventional electrolytic capacitor.

[Means to solve problems]

This invention consists of an insulating plate made of heat-resistant synthetic resin and a terminal in the form of a solderable metal piece.
The electrode plate, which is integrally formed with terminals arranged on both opposing sides of the insulating plate, is brought into contact with the outer surface of the sealing body attached to the opening of the exterior case in which the capacitor element is housed. It is characterized in that the leads led from the electrode plate and the terminals of the electrode plate are electrically connected on the side surface of the terminals.

Further, the leads led from the capacitor element and the terminals of the electrode plate are connected at a part of the side surface where a pair of terminals face each other, or at a notch provided in the same side surface where a pair of terminals are adjacent to each other. It is characterized by

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional view showing a first embodiment of the present invention, FIG. 3 is a perspective view showing the external shape of an electrode plate used in the first embodiment, and FIG. FIG. 3 is a perspective view showing a second embodiment of the invention.

In FIG. 1, an electrolytic capacitor 1 includes an electrode foil 3
A capacitor element 2 formed by winding a capacitor and an electrolytic paper 4 is housed in a bottomed cylindrical outer case 5 made of aluminum or the like. A sealing body 6 made of elastic rubber or the like is placed in the opening of the exterior case 5.

The lead 8 is electrically connected to the electrode foil 3 and also penetrates the sealing body 6 and protrudes from the outer surface of the sealing body 6 to the outside.

On the outer surface of the sealing body 6, an electrode plate 9 as shown in FIG. 3 is arranged. This electrode plate 9 consists of an insulating plate 11 made of a heat-resistant synthetic resin such as polyethylene terephthalate or epoxy, and a terminal 10 made of a solderable metal piece such as copper or iron.
Terminals 10 are integrally formed on a pair of both side surfaces of an insulating plate 11.

A protrusion 1 having a convex cross section is provided on one side of the terminal 10.
2 is provided. An insulating plate 11 made of synthetic resin such as epoxy is molded to cover this protrusion 12, and as a result, the terminal 10 made of a metal piece and the insulating plate 11 are joined to form an integrated electrode plate 9. .

Note that the dimension of one piece of the electrode plate 9 is approximately the same as the diameter dimension of the electrolytic capacitor 1, or is formed to be slightly longer.

Furthermore, a notch 13 is provided on the side surface of the terminal 10 of the electrode plate 9, as shown in FIG.
This notch 13 is provided in a part of the side surface where the pair of terminals 10 face each other.

As shown in FIG. 1, the lead 8 led from the electrolytic capacitor 1 is bent along the surface of the electrode plate 9 and the side surface of the terminal 10 on the side surface of the electrode plate 9, and is fitted into the notch 13 of the terminal 10. are doing. The lead 8 and the terminal 10 are electrically connected on the side surface of the notch 13 by spot welding, ultrasonic welding, or the like.

Further, the tip portion of the lead 8 is cut on the same plane as the back surface of the electrode plate 9, and as a result, a flat surface is formed on the back surface of the electrode plate 9.

Insulation between the outer case 5 and the terminals 10 of the electrode plate 9 is ensured by an outer sleeve 7 covering the outer surface of the outer case 5. This exterior sleeve 7 is made of synthetic resin such as vinyl chloride, and is in close contact with the surface of the exterior case 5.

The insulation between the exterior case 5 and the electrode plate 9 can be achieved by means other than the exterior sleeve 7 as shown in the first embodiment,
For example, a method such as applying synthetic resin to the upper surface of the electrode plate 9 may be used.

FIG. 4 is a perspective view showing a second embodiment of the present invention, in which an ordinary electrolytic capacitor 1 is used as in the first embodiment. Also,
Electrode plate 14 arranged on the end face of electrolytic capacitor 1
Similarly to the first embodiment, the insulating plate 16 is made of a heat-resistant synthetic resin such as epoxy, and the terminal 15 is made of a solderable metal piece such as copper or iron.

As shown in FIG. 4, a notch 17 is provided on the side surface of the electrode plate 14 adjacent to the pair of terminals 15, extending from the side surface toward the center of the electrode plate 14.
This notch 17 is provided with the electrolytic capacitor 1 to be placed.
The lead 8 has reached the protruding part.

The lead 8 led from the electrolytic capacitor 1 is in a state of protruding from the outer surface of the sealing body 6, that is,
Without being bent, it comes into contact with the side surface of the notch 17 of the terminal 15 provided on the electrode plate 14, and is welded to the terminal 15 by means such as spot welding.

In the case of the second embodiment, as compared with the first embodiment, there is no need to bend the leads 8, so it is easier to simplify the manufacturing process.
Furthermore, since no extra mechanical stress is applied to the leads 8 and the capacitor element 2 inside the electrolytic capacitor 1, the reliability of the finished product can be improved.

〔Effect of the invention〕

As described above, the present invention consists of an insulating plate made of a heat-resistant synthetic resin and a terminal in the form of a solderable metal piece. The electrode plate is brought into contact with the outer surface of the sealing body attached to the opening of the exterior case in which the capacitor element is housed, and the lead led from the capacitor element and the terminal of the electrode plate are connected.
Since the electrical connection is made on the side of the terminal, the lead led from the electrolytic capacitor is electrically connected to the terminal of the electrode plate, and also holds the electrode plate and allows the electrolytic capacitor body to stand on its own. enable. Therefore, the electrolytic capacitor obtained according to the present invention can be surface mounted on a substrate.

Furthermore, since the leads and the terminals of the electrode plate are welded together by spot welding or the like, they are strong against mechanical stress. Furthermore, in the case of the second embodiment, bending of the lead itself is hardly required. Therefore, no extra stress is applied to the leads during the manufacturing process, making it easier to maintain the reliability of the electrolytic capacitor itself.

Further, the leads led from the capacitor element and the terminals of the electrode plate are connected at a part of the side surface where a pair of terminals face each other, or at a notch provided in the same side surface where a pair of terminals are adjacent to each other. Therefore, the terminals that come into contact with the wiring on the board are formed wider than in the past. Therefore, when the electrolytic capacitor obtained according to the present invention is mounted on a substrate, the solder creeps up to the side surfaces of the terminals of the electrode plate and is fused, making it possible to establish a reliable electrical connection.

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

[Brief explanation of drawings]

FIG. 1 is a partially sectional view showing a first embodiment of the invention. Figure 2 is a partial sectional view showing the structure of a conventional leadless electrolytic capacitor, Figure 3 is a perspective view showing the external shape of the electrode plate used in the first embodiment, and Figure 4 is a partial cross-sectional view showing the structure of a conventional leadless electrolytic capacitor. FIG. 3 is a perspective view showing a second embodiment of the invention. DESCRIPTION OF SYMBOLS 1... Electrolytic capacitor, 2... Capacitor element, 3... Electrode foil, 4... Electrolytic paper, 5... Exterior case, 6... Sealing body, 7... Exterior sleeve, 8,
20... Lead, 9, 14... Electrode plate, 10, 1
5...Terminal, 11, 16, 18...Insulating plate, 12
...Protrusion, 13, 17...Notch, 19...Through hole, 21...Substrate, 22...Conductor portion, 23...
solder.

Claims (1)

[Claims] 1. An electrode consisting of an insulating plate made of a heat-resistant synthetic resin and a terminal in the form of a solderable metal piece, the terminals being arranged on a pair of opposing sides of the insulating plate and integrally formed. The plate is brought into contact with the outer surface of the sealing body attached to the opening of the exterior case in which the capacitor element is housed, and the lead led from the capacitor element and the terminal of the electrode plate are electrically connected on the side of the terminal. An electrolytic capacitor characterized by: 2. Claim 1, characterized in that the leads led from the capacitor element and the terminals of the electrode plate are connected at a notch provided in a part of a side surface where a pair of terminals face each other. Electrolytic capacitors listed in section. 3. The lead led from the capacitor element and the terminal of the electrode plate are connected at a notch provided on the same side surface where a pair of terminals are adjacent to each other. Electrolytic capacitor.