JPS61199621A - Electrolytic capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improvements in electrolytic capacitors, and particularly to a terminal structure of an electrolytic capacitor compatible with surface mounting on a substrate.

[Conventional technology]

In recent years, with the automation and high integration of electronic component mounting processes,
There is a demand for leadless electronic components that can be surface mounted on substrates.

Generally, when making an electrolytic capacitor 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 passes through a through hole 19 provided in the insulating plate 18 and protrudes from the back side of the insulating plate 18. , are bent along the back surface of the insulating plate 18. ′ In such a conventional leadless electrolytic sensor,
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 ordinary electrolytic capacitor 1.

(Problem to be Solved) However, in a leadless electrolytic capacitor with a conventional structure, only the lead 20 leading from the electrolytic capacitor 1 body comes into contact with the conductor portion 22 of the substrate 21. Therefore, The contact area between the electrolytic capacitor l and the conductor portion 22 has to be narrow.Alternatively, it is possible to form the tip of the lead 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;
It has been difficult to obtain a reliable connection state.

In addition, when electronic components are surface mounted on -a by reflow soldering, the leads 20 and the board 2 as shown in FIG.
The part where the conductor part 22 of lead 1 is connected by solder 23 is often the end face of lead 20, that is,
The melted solder 23 is applied to the conductor portion 22 on the back side of the lead 20.
Since it is in contact with the lead 2o, it hardly penetrates into the back surface of the lead 20 and is fused so as to creep up onto the end surface of the lead 2o. 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 2o may be insufficient. Depending on the state of soldering, the leads 2o may separate from the surface of the solder 23 after surface mounting due to vibration of the board 21, swelling of the sealing body 6 due to an increase in internal pressure of the electrolytic capacitor 1 body due to temperature rise, etc. There was a risk that it would get lost.

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, and therefore, unnecessary mechanical stress is applied to the insulating plate 18. Then, insulating plate 1
8 could come off from the electrolytic capacitor 1 body.

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 terminals in the form of metal pieces that can be soldered, and the electrode plate is integrally formed with the terminals arranged on a pair of opposing sides of the insulating plate. , the capacitor element 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. It is characterized by

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 cross-sectional view showing a first embodiment of the invention;
FIG. 3 is a perspective view showing the external shape of the electrode plate used in the first embodiment, and FIG. 4 is a perspective view showing the second embodiment of the invention.

In FIG. 1, an electrolytic capacitor 1 is formed by housing a capacitor element 2 formed by winding an electrode foil 3 and an electrolytic paper 4 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. 10 terminals on the surface
It consists of an integrally formed structure.

A protrusion 12 having a convex cross section is provided on one side of the terminal 10. Insulating plate 11 made of synthetic resin such as epoxy
is formed to cover this protrusion 12, and as a result, the terminal 10 made of a metal piece and the insulating plate 11 are joined, and -
A rod-shaped electrode plate 9 is formed.

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
A pair of terminals 10 are provided on a part of the side faces facing 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 bent along the notch 1 of the terminal 10.
3 is fitted. The lead 8 and the terminal 10 are connected to the notch 1
3, electrical connection is made 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.

The insulation between the outer case 5 and the terminals 10 of the electrode plate 9 is as follows.
This is secured by an exterior sleeve 7 that covers the outer surface of the exterior 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 outer case 5 and the electrode plate 9 may be achieved by means other than the outer sleeve 7 shown in the first embodiment, for example, by applying synthetic resin to the upper surface of the electrode plate 9. .

FIG. 4 is a perspective view showing a second embodiment of the invention.
As the electrolytic capacitor, a normal electrolytic capacitor 1 is used as in the first embodiment. Further, the electrode plate 14 disposed on the end face of the electrolytic capacitor 1 is also
It consists of an insulating plate 16 made of a heat-resistant synthetic resin such as epoxy, and a terminal 15 made of a piece of metal such as copper or iron that can be soldered. "As shown in FIG. 4, a notch 17 is provided on the side surface of the electrode plate 14 adjacent to a pair of terminals 15. This notch 17 extends from the side surface toward the center of the electrode plate 14. , the lead 8 of the mounted electrolytic capacitor l reaches 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 (the lead 8 is brought into contact with the side surface of the notch 17 of the terminal 15 provided on the electrode plate 14, and the lead 8 is not bent). Terminal 15 by means such as welding
will be welded.

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 metal piece that can be soldered. The formed 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 to each other on the side of the terminal. Since the lead led from the electrolytic capacitor is electrically connected to the terminal of the electrode plate, it also holds the electrode plate and allows the electrolytic capacitor body to stand on its own. 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, and the reliability of the electrolytic capacitor itself can be easily maintained.

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 conventional method.

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. FIG. 2 is a partial cross-sectional view showing the structure of a conventional leadless electrolytic capacitor, FIG. 3 is a perspective view showing the external shape of the electrode plate used in the first embodiment, and FIG.
FIG. 3 is a perspective view showing a second embodiment of the invention. 1... Electrolytic capacitor, 2... Capacitor element, 3...
Electrode foil, 4. Electrolytic paper, 5. Exterior case, 6. Sealing body, 7. Exterior sleeve, 8.20. Lead, 9.1
4... Electrode plate, 10.15... Terminal, 11.16.18
・・Insulating plate, 12・・Protrusion, 13.17・・Notch, 1
9...Through hole, 21...Substrate, 22...Conductor part, 23...
·solder.

Claims (3)

[Claims] (1) An electrode plate consisting of an insulating plate made of heat-resistant synthetic resin and a terminal in the form of a solderable metal piece, which is integrally formed with the terminals arranged on a pair of opposing sides of the insulating plate, is used as a capacitor. The capacitor element is brought into contact with the outer surface of the sealing body attached to the opening of the exterior case in which the 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. electrolytic capacitor. (2) A claim 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 the side surface where the pair of terminals face each other. The electrolytic capacitor according to item 1. (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 capacitors listed.