JPS5838926B2 - Manufacturing method of solid electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a solid electrolytic capacitor.

Conventional Koni/Densa of this type is made of tantalum, niobium,
An anode lead is installed in advance in a capacitor forming member made by press-molding and sintering a metal powder having a valve action, such as aluminum, into a cylindrical shape. At the same time as welding the lead wires, a second external lead wire is connected to the cathode layer formed on the surface of the capacitor forming member via an oxide layer and a semiconductor layer, and then the entire circumferential surface of the capacitor forming member is covered with a resin material. It is covered with

However, since the first and second external lead wires are connected one by one to the anode lead and the capacitor forming member, there is a drawback that workability is extremely low.

Therefore, it has been proposed to fix and connect a plurality of first external lead wires and second external lead wires to separate plates.

Although this method improves workability, a new problem has arisen in that a large amount of waste material is generated, which increases the cost of the capacitor and cannot be ignored.

Therefore, if such waste materials can be reduced as much as possible, it is desirable not only to reduce capacitor costs but also from the viewpoint of effective use of resources.

In view of these points, the present invention provides a method for manufacturing a solid electrolytic capacitor that can minimize the amount of waste material generated in the manufacturing process without sacrificing workability and reduce capacitor costs. One method will be explained.

First, as shown in FIG. 1, a capacitor forming member 2 having a valve action is formed on a band-shaped metal plate 1, for example, a sintered body made by press-molding tantalum powder into a cylindrical shape and sintering it. The capacitor forming member 2 is immersed in a chemical solution to form an oxide layer as a dielectric layer on its surface by chemical decomposition.

Next, after immersing the capacitor forming member 2 in the semiconductor mother liquor,
It is pulled up and subjected to a decomposition reaction in a high-temperature atmosphere furnace to deposit a semiconductor layer on the oxide layer.

After that, a cathode layer is formed on the semiconductor layer.

Next, as shown in FIG. 2, two sets of lead wires 6, 7 are led out from the strip-shaped plate material 5 at the same pitch as the metal wires 3 to form a chain lead 4 as shown in FIG. The lead wires 7 are bent in opposite directions and arranged in parallel on the metal plate 1.

Then, the bent portions 6a of the lead wires 6 are sequentially welded to the portions of the metal wires 3 where the semiconductor layer is not formed.

At this time, since the lead wire 7 is bent in the direction of the plate material, welding can be easily performed.

Therefore, if the welding electrode can be miniaturized to an emergency number, there is no need to shift the lead wire 7 from its normal position.

Then, only the metal wire 3 is cut from the section XX in the figure.

Next, as shown in FIG. 4, the lead wire 7 bent in the direction of the plate material is returned from the dotted line position to the solid line position, and the lead wire 7 is electrically connected to the cathode layer of the capacitor forming member 2 by soldering or the like.

Next, as shown in FIG. 5, the capacitor forming member and the welded portion between the metal wire 3 and the free end (bent portion) 6a of the lead wire 6 are covered with an exterior insulating material 8 such as a resin material. .

In addition to the dipping method using a liquid insulating material, any method can be used for the exterior, such as a fluid dipping method using a powdered resin, or a resin spraying method using a plasma jet.

Next, the lead wires 6 and 7 are cut from the Y-Y portion to complete the production of the capacitor.

In this way, when manufacturing a capacitor, only one chain lead 4 is required instead of the conventional two, so the amount of waste material after use is reduced and an inexpensive capacitor can be obtained.

Moreover, since a plurality of sets of lead wires 6 and 7 are led out from the chain lead 4, particularly if punching is used as the lead-out means, work efficiency is improved and mass production becomes possible.

Further, since the lead wires 6 and 7 are led out from the same plate material, the interval between them can be made constant, and the connection work to the capacitor forming member can be ensured.

Furthermore, the lead wire 7 is used to cut the metal wire 3 from the X-X portion.
Since this is done before connecting to the cathode layer, there is no deterioration in leakage current characteristics caused by the cutting operation.

That is, when the metal wire 3 is cut, the capacitor forming member 2 floats up using the cut portion of the metal wire 3 as a fulcrum.

At this time, if the lead wire 7 is connected to the cathode layer, lifting of the capacitor forming member 2 is inhibited, and stress acts on the connection boundary between the metal wire 3 and the capacitor forming member 2. The oxide layer formed in the same area is easily destroyed.

For this reason, leakage current characteristics may be significantly impaired.

However, according to the configuration of the present invention described above, when the metal wire 3 is cut, the lead wire 7 is not connected to the capacitor forming member 2 and is in a free state, so the above-mentioned trouble does not occur at all. do not.

It should be noted that the present invention is not limited to the above-mentioned embodiments; for example, the capacitor forming member may be of a sintered type, or may be a simple wire or a crushed material.

As described above, according to the present invention, it is possible to reduce waste materials generated in the capacitor manufacturing process, thereby reducing capacitor costs, and by leading the lead wires from the same plate material, the lead wire spacing can be made constant. This provides excellent effects such as significantly improving connectivity to capacitor forming members.

[Brief explanation of the drawing]

1 to 5 are front views for explaining the method of the present invention.

Claims (1)

[Claims] 1 A step of fixing a plurality of metal wires extending from a capacitor forming member having a valve action to a band-shaped metal plate, and forming a cathode layer on the surface of the capacitor forming member via an oxide layer and a semiconductor layer, and then A process of arranging a chain lead made of a plurality of pairs of two lead wires drawn out from a plate material in parallel on a metal plate, and welding the free end of one of the plurality of lead wires to the metal wire; There is a process of cutting off the metal wire slightly above the welded part between the metal wire and the lead wire, and then electrically connecting the free end of the other lead wire of the multiple sets of lead wires in the chain lead to the cathode layer. 1. A method for manufacturing a solid electrolytic capacitor, comprising the step of: