JPH0878295A - Solid electrolytic capacitor and its manufacture - Google Patents

Abstract

PURPOSE: To obtain a method for manufacturing a solid electrolytic capacitor in which the burning due to firing is prevented and the labor is reduced by facilitating the connection between a capacitor element and the outer leads of anode and cathode. CONSTITUTION: An outer lead 14 of anode is connected through a fuse 13 with an anode pin 12 planted on a capacitor element 11 comprising a sintered metal and an outer lead 15 of cathode is connected with the surface of the capacitor element 11. Both leads 14, 15 are passed through a hole 17 in the insulating base 16 and then they are bent outward in L-shape at the forward end part along the periphery of the hole. Finally, the hole 17 is filled with a sealing resin 18 thus sealing the leads 14, 15. Consequently, a can case 19 surrounding the main part, including the capacitor element 11, is sealed with respect to the insulating base 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor and a method for manufacturing the same, and more particularly to a solid electrolytic capacitor having a capacitor element housed in a can case and a method for manufacturing the same.

[0002]

2. Description of the Related Art There are various types of solid electrolytic capacitors, for example, a solid electrolytic capacitor having a capacitor element housed in a can case is shown in FIG.

This solid electrolytic capacitor has a solid electrolyte (not shown) formed on a sintered metal such as tantalum as shown in FIG.
The anode pin 2 is implanted in the capacitor element 1 on which manganese dioxide is formed, and the anode external lead 3 is connected to the tip of the anode pin 2 by welding, while the cathode external lead 4 is soldered to the side surface of the capacitor element 1. Connect by attaching. A thermosetting resin 6 such as an epoxy resin is filled in a state where a main part including the capacitor element 1 to which the anode and cathode external leads 3 and 4 are connected is housed in a metal can case 5.

The solid electrolytic capacitor is manufactured according to the following procedure. That is, as shown in FIG. 7, by welding the anode external lead 3 to the anode pin 2 of the capacitor element 1,
A cathode external lead 4 is provided on the side surface of the capacitor element 1.
An assembly body 7 in which is soldered is prepared. And
As shown in FIG. 8, the assembly body 7 is housed and arranged in the can case 5 in an upside down state. At this time, the assembly body 7 is positioned and arranged in the can case 5 while being supported by an appropriate jig (not shown).
Then, a thermosetting resin 6 such as an epoxy resin is injected into the can case 5 and then cured, so that the resin filled in the can case 5 molds a main part including the capacitor element 1 to form a solid electrolytic capacitor. Can be obtained.

[0005]

By the way, the solid electrolytic capacitor generally has a low failure rate and is required to have high reliability. However, it may ignite due to occurrence of a short-circuit failure or the like, and a burnout accident may occur. May be invited. Also,
In the method of manufacturing the solid electrolytic capacitor, when the assembly body 7 is manufactured, the anode outer lead 3 and the cathode outer lead 4 are separately connected to the capacitor element 1, so that many steps are required to manufacture the assembly body 7. The current situation is that it takes time and effort, which leads to a decrease in workability and an increase in product cost.

Therefore, the present invention has been proposed in view of the above problems, and an object of the present invention is to prevent burnout accidents due to ignition before assembling the capacitor element and the anode and cathode external leads. It is an object of the present invention to provide a solid electrolytic capacitor capable of easily reducing the number of steps and a manufacturing method thereof.

[0007]

As a technical means for achieving the above object, the solid electrolytic capacitor of the present invention comprises:
The anode external lead is connected via a fuse to the anode pin implanted in the capacitor element made of a metal sintered body, and the cathode external lead is connected to the surface of the capacitor element. And the tip thereof is bent outward in a substantially L-shape so as to be arranged along the peripheral edge of the hole of the insulating base, and both external leads are sealed in the hole by a sealing resin, and the capacitor element is included. It is characterized in that a can case surrounding the main part is sealed to an insulating base.

In the capacitor element, the solid electrolyte formed on the surface of the sintered metal is lead dioxide,
7 ', 8,8'-Tetracyanoquinodimethane complex salt [TCNQ
Salt], or polypyrrole. It is also possible to fill the internal space of the can case surrounding the main part including the capacitor element with resin.

In the method for manufacturing a solid electrolytic capacitor according to the present invention, the anode outer lead of the lead frame integrally formed with the anode outer lead and the cathode outer lead is implanted in a capacitor element made of a metal sintered body. Connecting the anode pin via a fuse and connecting the surface of the capacitor element to the cathode external lead,
Insert the assembly with the capacitor element attached to the lead frame into the hole of the insulating base, and lock the bent tips of both outer leads with the peripheral edge of the hole of the insulating base. In that state, insulate both outer leads with the sealing resin. Including a step of sealing in a hole of a base, a step of cutting a connection base end portion of the anode external lead with the cathode external lead to separate a lead frame into an anode external lead and a cathode external lead, and the capacitor element The method comprises a step of sealing a can case surrounding a main part to an insulating base.

[0010]

In the solid electrolytic capacitor according to the present invention, since the anode external lead is connected to the anode pin embedded in the capacitor element via the fuse, a current exceeding the allowable range flows or the current exceeds the allowable range. If the capacitor element heats up abnormally even with a current, the fuse is blown immediately. At that time, it is possible to prevent a current exceeding a permissible range and abnormal heat generation of the capacitor element to prevent a burnout accident due to ignition.

Further, in the method for manufacturing a solid electrolytic capacitor according to the present invention, by using a lead frame in which the anode outer lead and the cathode outer lead are integrally formed,
The capacitor element can be easily assembled with the external lead for the anode and the external lead for the cathode, which saves the labor.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

First, the solid electrolytic capacitor according to the present invention has a structure as shown in FIG. A solid electrolyte [not shown] was formed on the surface of a metal sintered body such as tantalum with lead dioxide, 7,7 ', 8,8'-tetracyanoquinodimethane complex salt [TCNQ salt] or polypyrrole. The anode pin 12 is implanted in the capacitor element 11 and the anode pin 12
The anode external lead 14 is connected to the tip of the via a fuse 13. The anode external lead 14 has a round bar shape or a flat plate shape and has a bent shape. The fuse 13 is connected to a horizontal upper end portion 14a of the anode outer lead 14. The horizontal lower end portion 1 bent laterally from the vertical intermediate portion 14b through the
4c. The fuse 13 is, for example, 5
A: It is possible to use a material having a rating of fusing within 5 seconds.

On the other hand, the cathode external lead 15 is connected to the cathode lead layer (not shown) formed on the surface of the capacitor element 11. Similar to the anode outer lead 14, the cathode outer lead 15 has a round bar shape or a flat plate shape and has a bent shape, and its vertical upper end portion 15a is connected to the capacitor element 11 by soldering.
It has a horizontal lower end portion 15c obtained by bending a vertical intermediate portion 15b extending from 5a laterally at a substantially right angle.

The anode and cathode external leads 14, 1
When 5 is a round bar, the horizontal lower ends 14c and 15c of both outer leads 14 and 15 are flattened by crushing to enable surface mounting on a printed wiring board.

The respective constituent members including the capacitor element 11, the fuse 13, the anode and cathode external leads 14 and 15 are assembled to the insulating base 16. A hole 17 is formed in the central portion of the insulating base 16 so as to penetrate therethrough.
The horizontal lower ends 14c, 15c of the anode and cathode external leads 14, 15 inserted into the holes are closely attached to the peripheral edge of the hole on the lower surface of the insulating base 16, and a sealing resin 18 such as an epoxy resin filled in the hole 17 is used to seal both outsides. The leads 14 and 15 are positioned, fixed and sealed.

Further, a can case 19 made of metal or resin is fitted into a flange portion 16a formed on the peripheral portion of the insulating base 16, and the can case 19 surrounds the main part including the capacitor element 11. . The peripheral portion of the can case 19 and the flange portion 1 of the insulating base 16
The can case 19 is sealed to the insulating base 16 by applying a sealing resin 20 such as an epoxy resin to the 6a.

For a solid electrolytic capacitor having a small capacity and a low withstand voltage, air can be enclosed in the can case 19, but for a solid electrolytic capacitor having a large capacity and a high withstand voltage, an epoxy resin is used in the can case 19. It is also possible to mold by filling with a resin such as.

The solid electrolytic capacitor having the above-mentioned structure is manufactured by the following procedure, which will be described with reference to FIGS.

First, as shown in FIG. 2, there is prepared a lead frame 21 in which the anode external lead 14 and the cathode external lead 15 having the above-mentioned shape are integrally formed. The lead frame 21 is a vertical intermediate portion 1 of the cathode external lead 15.
The horizontal upper end portion 14a of the anode outer lead 14 is connected and integrated with 5b.

On the other hand, one end of a fuse 13 is welded to the tip of the anode pin 12 of the capacitor element 11 having the above-described structure, and the fuse 13 is welded to the anode pin 12 so that the capacitor element 11 is connected to the lead frame 2
Attach to 1. That is, the other end of the fuse 13 is connected to the horizontal upper end portion 14a of the anode outer lead 14 with a conductive paste or the like, and the cathode lead layer (not shown) on the surface of the capacitor element 11 is connected to the vertical upper end portion 1 of the cathode outer lead 15.
5a is connected by soldering. As described above, the assembly body 22 including the capacitor element 11, the fuse 13, and the lead frame 21 is manufactured.

Next, as shown in FIG. 3, the assembly body 22 is assembled to the insulating base 16. That is, with the assembly body 22 and the insulating base 16 turned upside down, the assembly body 22 is inserted into the hole 17 of the insulating base 16.
The external lead 14 for the anode and the external lead 15 for the cathode.
The horizontal lower ends 14c and 15c of the
To the periphery of. In this state, a sealing resin 18 such as an epoxy resin is applied to the holes 17 of the insulating base 16 to position and fix the assembly body 22 on the insulating base 16 and seal the outer leads 14 and 15.

After the assembly body 22 is assembled to the insulating base 16 in this manner, as shown in FIG. 4, a connecting base to the vertical intermediate portion 15b of the cathode outer lead 15 located at the horizontal upper end portion 14a of the anode outer lead 14 is formed. The lead frame 21 is separated into the anode external lead 14 and the cathode external lead 15 by cutting off the end portion (broken line portion in the figure) by an appropriate means.

Thereafter, as shown in FIG. 5, a can case 19 is fitted into the flange portion 16a of the insulating base 16, and the can case 19 is used to attach the capacitor element 1 to the can case 19.
The main part including 1 is surrounded. A sealing resin 20 such as an epoxy resin is applied to the peripheral portion of the can case 19 and the flange portion 16a of the insulating base 16 to seal the can case 19 to the insulating base 16 to obtain the solid electrolytic capacitor of FIG. .

For a solid electrolytic capacitor having a large capacity and a high withstand voltage, when the can case 19 is filled with a resin such as epoxy resin, holes for resin injection and exhaust are provided in the insulating base 16 although not shown. After the holes are provided and the can case 19 is sealed to the insulating base 16, the resin is injected through the resin injection hole and then the resin injection and exhaust holes are sealed, or the assembly is assembled. Body 22
Is attached to the insulating base 16 to separate the lead frame 21 into the anode outer lead 14 and the cathode outer lead 15, and the lead frame 21 is housed in a can case 19 in which a resin is previously injected. It may be sealed to the insulating base 16.

[0026]

According to the solid electrolytic capacitor of the present invention,
By interposing a fuse between the anode pin of the capacitor element surrounded by the can case and the anode external lead, a burnout accident due to ignition can be prevented, and the reliability of the product is significantly improved. Further, according to the manufacturing method of the present invention, since the manufacturing is performed based on the assembly body using the lead frame, the manufacturing is easy and the work can be simplified, and the workability is greatly improved and the product The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a solid electrolytic capacitor according to the present invention.

FIG. 2 is a front view showing an assembly body in which a capacitor element is attached to a lead frame for explaining the manufacturing method of the present invention.

FIG. 3 is a cross-sectional view showing how to assemble the assembly of FIG. 2 to an insulating base.

FIG. 4 is a cross-sectional view showing a state in which the lead frame of the assembly assembled to the insulating base of FIG. 3 is separated into an anode outer lead and a cathode outer lead.

FIG. 5 is a cross-sectional view showing how to attach a can case to the insulating base of FIG.

FIG. 6 is a sectional view showing a conventional example of a solid electrolytic capacitor.

FIG. 7 is a front view showing an assembly body including a capacitor element for explaining a conventional manufacturing method.

FIG. 8: Store the assembly of FIG. 7 in a can case,
Sectional drawing which shows the state which filled the resin in the can case.

[Explanation of symbols]

 11 Capacitor Element 12 Anode Pin 13 Fuse 14 Anode External Lead 15 Cathode External Lead 16 Insulating Base 17 Hole 18 Sealing Resin 19 Can Case 21 Lead Frame 22 Assembly

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H01G 9/24 C

Claims (4)

[Claims] 1. An external lead is connected to an anode pin implanted in a capacitor element made of a metal sintered body via a fuse, and a cathode external lead is connected to the surface of the capacitor element, and both external leads are connected. Is inserted into the hole of the insulating base, the tip thereof is bent outward in a substantially L-shape and arranged along the peripheral edge of the hole of the insulating base, and both external leads are sealed in the hole by the sealing resin, A solid electrolytic capacitor, characterized in that a can case surrounding a main part including the capacitor element is sealed to an insulating base. 2. The capacitor element, wherein the solid electrolyte formed on the surface of the metal sintered body is lead dioxide, 7,7 ′,
8,8'-tetracyanoquinodimethane complex salt [TCNQ salt],
The solid electrolytic capacitor according to claim 1, wherein the solid electrolytic capacitor is made of any one of polypyrrole. 3. The solid electrolytic capacitor according to claim 1, wherein an internal space of a can case surrounding a main part including the capacitor element is filled with resin. 4. An anode pin embedded in a capacitor element made of a metal sintered body is connected via a fuse to the anode external lead of a lead frame integrally formed with an anode external lead and a cathode external lead. At the same time, the step of connecting the surface of the capacitor element to the cathode external lead, and inserting the assembly body, in which the capacitor element is assembled to the lead frame, into the holes of the insulating base, and the bent tips of both outer leads are provided with holes of the insulating base. The lead frame is fixed to the outside of the anode by locking at the periphery and sealing both outer leads in the holes of the insulating base with the sealing resin in that state, and cutting the base end of the connection between the anode outer lead and the cathode outer lead. Insulating the process of separating the lead and the cathode external lead and the can case surrounding the main part including the capacitor element A method of manufacturing a solid electrolytic capacitor, comprising the step of sealing to a base.