JPS61220320A - 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, as the mounting process of electrolytic capacitors has become more automated and highly integrated, there has been a demand for leadless electrolytic capacitors 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 11 is arranged on the end face of the electrolytic capacitor 1, and a portion 7 leading from the electrolytic capacitor 1 is inserted through a through hole 15 provided in the insulating plate 11 and protrudes from the back side of the insulating plate 11. In addition, the insulating plate 11
It is folded along the back side.

In such a conventional leadless electrolytic capacitor l, a substantially flat surface is formed on the back surface of the insulating plate 11, so that the substrate 12 can be easily connected to the substrate 12 without changing the structure of the ordinary electrolytic capacitor 1.
surface mounting capability (possible).

[Problem to be solved]

However, in the leadless electrolytic capacitor 1 having a conventional structure, only the part 7 from the capacitor element 2 comes into contact with the conductor part 13 of the substrate 12. Therefore, the contact area between electrolytic capacitor 1 and conductor portion 13 has to be narrow. Alternatively, it is possible to form the tips of the leads 7 into a flat shape, but it has been difficult to provide a sufficient contact area. Therefore, lead 7
The area where the conductor portion 13 of the substrate 12 comes into contact is narrow, making it difficult to obtain a highly reliable connection.

Furthermore, when the electrolytic capacitor l is generally surface mounted by reflow soldering, the portion where the lead 7 and the conductor portion 13 of the board 12 are connected by the solder 14 is the end face of the lead 7, as shown in FIG. There are many cases. That is, the melted solder 14 is applied to the conductor portion 13 on the back surface of the lead 7.
Since it is in contact with the lead 7, it hardly penetrates into the back surface of the lead 7 and is fused so as to creep up onto the end surface of the lead 7.

Therefore, if the area of the end face of lead 7 is small, solder 1
The contact area with 4 will be reduced. Therefore, the electrical connection between the conductor portion 13 of the substrate 12 and the lead 7 may be insufficient.

In addition, if the soldering condition is poor, after surface mounting, the leads 7 may be damaged by the solder 14 due to vibration of the board 12 or swelling of the sealing body 6 due to an increase in internal pressure of the electrolytic capacitor 1 due to temperature rise.
In addition, since the part 7 led from the electrolytic capacitor 1 is bent along the back surface of the insulating plate 11 after passing through the through hole 15 of the insulating plate 11, Mechanical stress during bending of the leads 7 may affect the mechanical strength, electrical characteristics, etc. of the electrolytic capacitor 1, making it difficult to maintain reliability.

Furthermore, since the insulating plate 11 and the electrolytic capacitor 1 are only connected by bending the leads 7,
Mechanically weak. Therefore, if extra mechanical stress is applied to the insulating plate 11, there is a risk that the insulating plate 12 will separate from the electrolytic capacitor 1.

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

[Means to solve problems]

In the present invention, a sealing body is attached to the opening of an exterior case in which a capacitor element is housed, and a plate-shaped terminal made of a metal that can be soldered is provided on the outer surface of the sealing body. The electrode plate consists of a thick insulating plate made of heat-resistant synthetic resin, and the terminals are arranged on both sides of the insulating plate so that the terminals and the back side of the insulating plate are located on almost the same plane. It is characterized in that the lead leading from the capacitor element is welded to the top or side surface of the terminal of the electrode plate.

Further, the insulator of the electrode plate is characterized in that the upper surface, the side surface, or a part of these surfaces is provided with a groove-shaped notch into which the lead led from the capacitor element is inserted.

〔Example〕

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

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

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 7 is electrically connected to the electrode foil 3 and penetrates the sealing body 6 to protrude 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 has a structure in which a plate-shaped terminal 8 made of metal that can be soldered and an insulating plate 10 made of heat-resistant synthetic resin and formed at least thicker than the terminal 8 are integrally molded. Become.

Further, the terminals 8 are arranged on a pair of opposite side surfaces of the insulating plate 10, and are formed so that the back surfaces of the terminals 8 and the insulating plate 10 are located on substantially the same plane. the result,
A substantially flat surface is formed on the back surface of the electrode plate 9, and a continuous step formed by the insulating plate 10 made of synthetic resin is formed on the top surface.

Furthermore, this electrode plate 9 is connected to the insulating plate 1 as shown in FIG.
A groove-shaped notch 16 is provided on a part of the upper surface and side surface of the 0. This notch 16 is formed to have a width approximately the same as that of the portion 7 leading from the electrolytic capacitor 1 .

In this example, the external shape of the entire electrode plate 9 was formed into a rectangle as shown in FIG. 3, and the dimension of the negative side was formed to be slightly longer than the diameter of the electrolytic capacitor l.

The electrode plate 9 is connected to the electrolytic capacitor 1 as shown in FIG.
The electrode plate 9 is arranged to face the outer surface of the sealing body 6, and the protrusion formed by the step of the insulating plate 10 of the electrode plate 9 is in direct contact with the end surface of the outer case 5. Further, the lead 7 led from the electrolytic capacitor 1 is bent so as to fit into the notch 16 on the upper surface of the electrode plate 9, and is led to the upper surface of the terminal 8 of the electrode plate 9. Further, the connection between the terminal 8 of the electrode plate 9 and the lead 7 leading from the electrolytic capacitor 1 is performed on the upper surface of the terminal 8 by spot welding, ultrasonic welding, or the like.

[For production]

As shown in FIG. 1, an insulating plate 10 of an electrode plate 9 is in contact with the outer surface of the sealing body 6 of the electrolytic capacitor 1 to support the electrolytic capacitor l. Further, the lead 7 led from the electrolytic capacitor 1 is fitted into the notch 16 of the electrode plate 9,
It is bent along this notch 16 and welded to the upper surface of the terminal 8 of the electrode plate 9. Therefore, the electrolytic capacitor 1 can stand on its own.

Further, on the back surface of the electrode plate 9, the back surface of the terminal 8 electrically connected to the lead 7 and the back surface of the insulating plate 10 are located on substantially the same plane, forming a substantially flat surface.

Therefore, the electrolytic capacitor l according to the embodiment of the present invention can be surface mounted on a substrate.

Although the lead 7 and the terminal 8 of the electrode plate 9 are electrically connected on the top surface of the terminal 8, it is possible to connect the lead 7 and the terminal 8 on the side surface of the terminal 8 as well.

In this case, a more reliable connection state can be realized.

〔Effect of the invention〕

As described above, in the present invention, a sealing body is attached to the opening of an exterior case in which a capacitor element is housed, and a plate-shaped terminal made of a metal that can be soldered is attached to the outer surface of the sealing body. It consists of an insulating plate made of heat-resistant synthetic resin that is thicker than the terminal, and is integrally formed with the terminals arranged on both sides of the insulating plate so that the back surfaces of the terminal and the insulating plate are located on almost the same plane. The electrode plate is in contact with the electrode plate, and the lead led from the capacitor element is welded to the top or side surface of the terminal of the electrode plate.

Further, the insulator of the electrode plate is characterized by having a groove-shaped notch on the top surface, side surface, or a part of these surfaces, into which the lead led from the capacitor element is inserted. is electrically connected to the terminal of the electrode plate by means such as spot welding, and also holds the electrode plate in the notch of the insulating plate, allowing the electrolytic capacitor to stand on its own.

Furthermore, on the back surface of the electrode plate, the terminals of the electrode plate and the back surface of the insulating plate are located on substantially the same plane, forming a substantially flat surface.

Therefore, the electrolytic capacitor obtained according to the present invention can be surface mounted on a substrate without changing the conventional structure.

Furthermore, since the electrolytic capacitor and the electrode plate are anchored by welding the leads and terminals, and by fitting the leads into the notches of the insulating plate, they are strong against mechanical stress.

Furthermore, the leads led from the electronic component and the terminals of the electrode plate are electrically connected on the upper surface of the - pair of terminals, so that the back and end surfaces of the terminals that come into contact with the wiring on the board. For example, it is formed wider than before. 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 the drawing]

FIG. 1 is a partially sectional view showing an embodiment of the invention. FIG. 2 is a partial cross-sectional view showing the structure of a conventional leadless electronic component, and FIG. 3 is a perspective view showing the external shape of an electrode plate used in an embodiment of the present invention. 1. Electrolytic capacitor, 2. Capacitor element. 3. Electrode foil, 4. Electrolytic paper, 5. Exterior case, 6.
- Sealing body, 7... Lead, 8... Terminal, 9... Electrode plate,
10.11...Insulating plate, 12...Substrate, 13...Conductor portion, 14...Solder, 15...Through hole, 16...Notch.

Claims (2)

[Claims] (1) A sealing body is attached to the opening of the exterior case in which the capacitor element is housed, and a plate-shaped terminal made of solderable metal is attached to the outer surface of the sealing body, and a plate-shaped terminal made of a solderable metal is attached to the outer surface of the sealing body. The terminal is placed on both sides of the insulating plate so that the terminals and the back side of the insulating plate are located on almost the same plane, and the electrode plate is in contact with the insulating plate made of heat-resistant synthetic resin. An electrolytic capacitor characterized in that a lead led from a capacitor element is welded to the top or side surface of a terminal of an electrode plate. (2) A patent claim characterized in that the insulator of the electrode plate is provided with a groove-shaped notch on a top surface, a side surface, or a part of a plurality of these surfaces into which a lead led from a capacitor element is inserted. The electrolytic capacitor according to item 1.