JPH05326342A - Manufacture of solid electrolytic capacitor - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a solid electrolytic capacitor in which a product is reduced in size by using a foil and is increased in capacitance. CONSTITUTION:An anode foil 6 is mounted at a lead frame 2 for forming an anode side terminal 12 or a conductor piece 4 mounted at the frame 2. A solid electrolyte layer 16 and a conductive layer 18 are generated on a surface of the foil 6 to form a capacitor element 20, an anode side terminal 22 is connected to the element 20, and resin-sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a solid electrolytic capacitor using a solid electrolyte such as an organic conductive polymer as an electrolyte.

[0002]

2. Description of the Related Art Conventionally, a solid electrolytic capacitor has a block-shaped anode body on the anode side, which is subjected to necessary treatment as a capacitor element on its surface, and then an anode side terminal and a cathode side terminal are drawn out, Is resin-sealed. In the solid electrolytic capacitor using such an anode body, the appearance shape is determined by the anode body, the appearance accuracy can be improved, and the solid electrolytic capacitor can be made robust.

[0003]

However, in this solid electrolytic capacitor, since the anode body is a block body, there is a limit to the expansion of the surface area, and a large increase in capacity is expected even if subjected to extreme etching treatment. Can not do it. Moreover, the size of the anode body becomes a factor that hinders the miniaturization of the solid electrolytic capacitor. In addition, there is a drawback in that it is difficult to carry out a process in the middle of processing or to collectively process the products because of the form of the anode body, and it is difficult to make the products uniform.

On the other hand, although the foil can easily increase the surface area and contributes to the increase in the capacity per unit area, its flexibility may damage the solid electrolyte layer formed on the foil surface.

Therefore, an object of the present invention is to provide a method of manufacturing a solid electrolytic capacitor which uses a foil to reduce the size of a product and increase the capacity.

[0006]

That is, according to the method for producing a solid electrolytic capacitor of the present invention, an anode foil (2) is formed on a lead frame (2) forming an anode side terminal (12) or a conductor piece (4) attached to the lead frame. 6) is attached, and an electrolyte layer (solid electrolyte layer 16) and a conductive layer (18) are attached to the surface of this anode foil.
Is formed to form a capacitor element (20), the cathode side terminal (22) is connected to this capacitor element, and then resin sealing is performed.

[0007]

The combination of the lead frame and the anode foil is to collectively perform the processing as the capacitor element and the sealing on the lead frame. Further, since the lead frame is made of a conductive material, it can be used as an anode side terminal itself.

Therefore, in the present invention, the continuous anode foil is attached to the lead frame or the conductor piece attached to the lead frame so as to straddle it. In this case, the anode foil and the lead frame are electrically connected to each other, and the anode foil can be provided with a treatment necessary as a capacitor element on the lead frame, that is, an electrolyte layer and a conductive layer. Each capacitor element is resin-sealed after the cathode side terminal is connected on the lead frame. Then, the solid electrolytic capacitor as a product is formed by separating the capacitor element from the lead frame together with the anode side terminal.

[0009]

The present invention will be described in detail below with reference to the embodiments shown in the drawings.

[0010]

FIG. 1 shows an embodiment of the method for manufacturing a solid electrolytic capacitor of the present invention. FIG. 1A shows a process of attaching the conductor piece 4 and the anode foil 6 to the lead frame 2, and FIG. 1B shows a cross section of a solid electrolytic capacitor as a product.

The lead frame 2 is formed by punching out a conductor material plate such as aluminum, and has a plurality of anode-side terminals 12 which are units of a capacitor element to be obtained, along with a positioning hole 10 in a continuous strip portion 8. It is formed at intervals. Each anode side terminal 12 of this lead frame 2
Attach the conductor piece 4 to the end of the. The conductor piece 4 is formed of a conductor material such as aluminum, and is electrically connected to each anode terminal 12 by a connecting means such as welding and is firmly and mechanically fixed. This conductor piece 4 is functionally different from the conventional anode body and serves as a reinforcing member for the anode foil 6. That is, the conventional anode body is made solid and the soft anode foil 6 is reinforced by the mechanical strength of the conductor piece 4. The anode foil 6 is attached by folding back the front and back sides of each conductor piece 4, and the anode foil 6 is also connected by welding means such as ultrasonic welding or adhesion means using an adhesive. For the anode foil 6, a film-forming metal foil such as an aluminum foil is used.

As shown in FIG. 2 (A), a dielectric oxide film 14 is formed on the surface of the anode foil 6 by an etching treatment and then a chemical conversion treatment, and vapor-phase polymerization, chemical polymerization or A solid electrolyte layer 16 made of a polymer layer such as polypyrrole is formed by electrolytic polymerization, and a conductive layer 18 is formed thereon by applying a conductive paste or the like. Since the anode foil 6 is installed so as to straddle each anode-side terminal 12, it is cut in accordance with the width of the anode-side terminal 12. In this case, since the lead frame 2 has the positioning hole 10 formed therein,
The anode foil 6 can be cut based on the positioning holes 10. As a result, a plurality of capacitor elements 20 including the anode side terminal 12 as a unit are formed on the anode side terminal 12 of the lead frame 2.

The conductive layer 18 of each capacitor element 20
The cathode side terminal 22 is connected to the upper surface of the above with a conductive adhesive 24 at a position corresponding to the anode side terminal 12.

Then, as shown in FIG. 2B, each of the capacitor elements 20 is provided with a sealing resin 2 on the lead frame 2.
Resin sealing is individually performed using 6. In this case, the resin encapsulation is performed mainly on the capacitor element 20, but because the external terminals are formed, the encapsulation range is the anode side terminal 12 and the cathode side terminal 2.
2 is set so as to be drawn to the outside of the sealing resin 26 with a sufficient length.

After this resin sealing, the capacitor element 20 is cut from the lead frame 2. In this case, the capacitor element 20 is cut off from the lead frame 2 together with the anode side terminal 12 while leaving the anode side terminal 12 in a length required as an external terminal on the side of the capacitor element 20. Since the lead frame 2 has the positioning hole 10, the capacitor element 20 can be separated based on the positioning hole 10. Further, since the sealing resin 26 can be molded into a rectangular parallelepiped by using a molding die or the like, as shown in FIG. 2B, the anode side terminal 12 and the cathode side terminal 22 are the sealing resin 2
The surface of the exterior body formed in 6 is bent and subjected to a forming process to form an external terminal.

According to such a manufacturing method, the attachment of the anode foil 6, the formation of the capacitor element 20, and the sealing process with the sealing resin 26 can be collectively performed on the lead frame 2, and the manufacturing process is still in progress. Since the product can be transported by the lead frame 2 as a unit, it is possible to manufacture a solid electrolytic capacitor having high uniformity and high capacity by the anode foil 6, and it is possible to improve the production efficiency.

The conductor piece 4 of the above embodiment may be omitted, and as shown in FIG.
Alternatively, the capacitor element 20 may be formed by using the conductor piece 4 and the anode-side terminal 12 of the above-mentioned embodiment also as the anode piece and folding back and connecting the anode foil 6 thereon. In this way, as shown in FIG. 3B, the structure of the solid electrolytic capacitor can be simplified by omitting the conductor piece 4.

When the lead frame 2 is made of aluminum or the like, a solder layer 28 may be formed on the surface of the lead frame 2 as a metal layer that can be selectively soldered by plating. In this case, the cathode-side terminal 22 having the same solder layer 30 formed thereon is used. The plating treatment may be performed in advance on the base material of the lead frame 2 or the cathode side terminal 22.

In the above embodiment, the anode foil 6 was cut into a predetermined width and then the capacitor element 20 was resin-sealed. However, after the anode foil 6 was cut into a predetermined width, as shown in FIG. As shown in (A), each capacitor element 20 may be collectively installed in the cavity 36 of the molding dies 32 and 34 and resin-sealed with the sealing resin 26.

Then, as shown in FIG. 4 (B), the capacitor element 20 forming a chain with the sealing resin 26 is cut at the portion of the sealing resin 26, and the lead frame 2 is formed.
Even if the anode side terminal 12 is cut from the above and the anode side terminal 12 and the cathode side terminal 22 are subjected to forming processing, the solid electrolytic capacitor similar to the above-mentioned embodiment can be obtained.

[0021]

As described above, according to the present invention,
Since it was folded back to the lead frame or the conductor piece attached to the lead frame and the anode foil was attached, a capacitor element was formed on the anode foil, and after sealing it with resin, it was cut to obtain a solid electrolytic capacitor. With the increase in capacity due to the use of the anode foil, the processing of each capacitor element can be performed collectively on the lead frame, the product can be made uniform and the transportation processing during production can be facilitated, and the production efficiency can be improved. .

[Brief description of drawings]

FIG. 1 is a perspective view showing a lead frame to which a conductor piece and an anode foil are attached in an embodiment of a method for manufacturing a solid electrolytic capacitor of the present invention, and a vertical sectional view of a solid electrolytic capacitor as a product.

FIG. 2 is a sectional view showing a capacitor element on a lead frame and a partial sectional view showing resin sealing of the capacitor element on the lead frame.

FIG. 3 is a sectional view of another capacitor element and a vertical sectional view of a solid electrolytic capacitor using the other capacitor element.

4A and 4B are a sectional view showing resin sealing using a mold of a capacitor element and a partial sectional view showing resin sealing of a capacitor element on a lead frame.

[Explanation of symbols]

 2 Lead frame 4 Conductor piece 6 Anode foil 12 Anode side terminal 16 Solid electrolyte layer 18 Conductive layer 20 Capacitor element 22 Cathode side terminal

Claims (1)

[Claims] 1. An anode foil is attached to a lead frame or a conductor piece attached to the lead frame, which constitutes the anode side terminal,
A method for producing a solid electrolytic capacitor, which comprises forming an electrolyte layer and a conductive layer on the surface of this anode foil to form a capacitor element, connecting a cathode side terminal to this capacitor element, and then sealing with a resin.