JPH04199809A - Device and method for forming lead wire terminal for electrolytic capacitor - Google Patents

Abstract

PURPOSE:To perform perfect forming by constituting a bottomed open container to a crater-like shape, with the bottom surface being constituted of a conductive and permeable material or a permeable material. CONSTITUTION:Lead wire terminals connected with lead wires arranged through the inside bottom surface of a bottom open container 1 and an electrode jig 5 put on the outside bottom surface of the container 1 are provided and the jig 5 is brought into contact with the anode of a power source 6. At the same time, the aluminum flat sections 3 of the lead wire terminals are dipped in a forming liquid 8 connected with the cathode of the power source 6 for forming. The container 1 is formed to a crater-like shape 2 and at least its bottom surface is constituted of a material containing a conductive and permeable materials or a permeable material. Therefore, voltages can be surely applied across the lead wire terminals and the variation of the produced state of dielectric oxide films can be reduced.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention provides a chemical conversion device for lead wire terminals for electrolytic capacitors in which a lead wire and an aluminum wire are welded and the aluminum wire is flattened. Concerning chemical conversion methods.

(Prior Art) A lead wire terminal for a dielectric capacitor is made up of a lead wire made of a copper ply wire and an Al wire welded together, and a flat part made by pressing a part of the Al wire. And this Al
A dielectric oxide film is formed on the wire and the flat portion by chemical conversion treatment, and the wire and the flat portion are connected to the electrode foil of the electrolytic capacitor. The above-mentioned chemical conversion treatment method is, for example, disclosed in Japanese Patent Application Laid-Open No. 1-1793.
There is a technique described in Publication No. 08. That is, as shown in FIG. 4, the lead wire 22 of the lead wire terminal is inserted into the bottomed open container 21 made of AI, and the lead wire 22 is placed on the outer bottom surface of the bottomed open container 21. After adsorbing and holding with the tool 24, the flat part 23 is turned upside down and immersed in a chemical solution, and a voltage is applied by the electrode jig 24 connected to the anode of the power source and the chemical solution connected to the cathode to perform chemical conversion treatment. This is what we do.

The necessary conditions for this kind of chemical conversion treatment are that the lead wire must be in reliable contact with the inner bottom surface of the bottomed open container, and that there be no strong contact between the flat parts immersed in the chemical liquid, and that the chemical liquid should wet the entire flat area. A dielectric oxide film is generated evenly,
and to prevent current concentration from occurring due to biased insertion of lead wire terminals into a bottomed open container. It is essential to have a distributed alignment.

However, in the method described above, the number of lead wire terminals inserted into the bottomed open container 21 is large, and the thickness and width of the lead wire 22 and the Al wire and the flat portion 23 are different, so that the flat portion 23 is In some cases, the lead wires 22 are so intertwined that the tips of the lead wires 22 do not come into contact with the bottom surface of the bottomed open container 21, or the flat parts 23 are in strong contact with each other, making it impossible for the chemical liquid to enter. There was a problem that the terminals were immersed in the chemical solution more deeply than necessary, and a properly dispersed and aligned state could not be obtained.

As a result, the dielectric oxide film may be insufficient due to insufficient application of an atomizing voltage, or there may be unformed areas, or the concentration of current during anodizing may cause it to turn black and become brittle, or over time. It had drawbacks such as rusting over time.

(Problems to be Solved by the Invention) As described above, with conventional chemical conversion means for lead wire terminals, the formation of a dielectric oxide film is insufficient due to the lead wire not coming into contact with the bottomed open container, and the unchemically formed portion is Discoloration, brittleness, rust, etc. due to generation or current concentration have been problems.

The present invention has been made to eliminate these drawbacks, and an object of the present invention is to provide a chemical conversion apparatus and a chemical conversion method for lead wire terminals for electrolytic capacitors that can perform complete chemical conversion treatment.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a lead wire terminal in which a lead wire is brought into contact with the inner bottom surface of the bottomed open container, and an electrode jig arranged in the outer bottom surface of the bottomed open container. A lead wire terminal for an electrolytic capacitor is formed by contacting the electrode jig with the anode of a power source and immersing the aluminum flat part of the lead wire terminal in a chemical solution to which the cathode of the power source is connected. In the chemical conversion apparatus, the bottomed open container is funnel-shaped, and at least the bottom surface is conductive.
A chemical conversion device for a lead wire terminal for an electrolytic capacitor, characterized in that the device is made of a material that is magnetically permeable or contains a magnetically permeable material; , a step of inserting the lead wire of the lead wire terminal and adsorbing and holding the lead wire with an electrode jig placed on the outer surface of the bottomed open container; and immersing the aluminum flat part of the lead wire terminal in a chemical solution. A lead for an electrolytic capacitor, characterized in that the lead wire terminal undergoes a step of applying a chemical conversion treatment to the lead wire terminal by applying a voltage from an anode connected to an electrode jig and a cathode connected to a chemical solution after this step. This is a method of chemically forming wire terminals.

(Function) In the present invention, since the bottomed open container is formed in a funnel shape, even if a large number of lead wire terminals are inserted into the bottomed open container in order to chemically form them all at once, they will not be inserted along the funnel shape. This ensures that the lead wire comes into contact with the inner bottom surface of the bottomed open container. In addition, when a large number of lead wires are grouped together, the lead wire with a small volume is placed at the funnel-shaped bottom with a small area, and the flat part with a large volume is located outside the container along the funnel.
The overall shape is like a cone, and there is no strong contact between the flat parts, and each lead wire terminal can be arranged easily.

Therefore, the lead wire is in reliable contact with the bottom surface of the bottomed open container, and a sufficient dielectric oxide film can be formed on the flat portions. These effects are achieved by the fact that the shape of a large number of lead wire terminals and the funnel shape formed on the inner surface of the bottomed open container almost match each other.

(Example) As shown in FIG. 1, the inner surface of a bottomed open container 1 made of aluminum, for example, is formed into a funnel shape 2. A lead wire terminal consisting of an aluminum wire with a flat portion 3 formed thereon and a welded lead wire 4 is inserted into the bottomed open container 1 so that the lead wire 4 contacts the inner bottom surface of the container 1. A magnetic electrode jig 5 is disposed on the outer bottom surface of the container 1 containing the lead wire terminals in this manner. This electrode jig 5 is connected to the anode of a power source 6. In this state, the lead wire 4 is attracted and held by the magnetism of the electrode jig 5, and does not fall off even if it is turned upside down.Since the tip of the lead wire 4 is in contact with the inner bottom surface of the container 1, the flat part 3 is also held at an approximately constant level. You can adjust the height. The lead wire terminal thus housed in the container 1 is immersed in the chemical conversion liquid 8 in the chemical conversion tank 7, but since the heights of the flat portions 3 are almost the same as described above, the chemical conversion is carried out to the same position. It can be immersed in liquid 8. And chemical liquid 8
Since the cathode of the power source 6 is connected to, by turning on the power source 6, it is possible to chemically convert the portion of the flat portion 3 etc. immersed in the chemical conversion liquid 8.

Note that this FIG. 1 shows a chemical conversion apparatus.

In such a chemical conversion device, for example, 506 lead wire terminals are housed in a container, and the lead wire terminals that have been subjected to chemical conversion for 150 times are used as samples, and the variation in leakage current and its drop state when 110 V is applied is measured. Shown in Figure 2.

The conventional example was chemically formed under the same conditions as the example except that 750 lead wire terminals were housed in the jig shown in FIG.

As is clear from this, the conventional leakage current has large variations as shown in FIG. 2 and the fall time is slow, whereas the embodiment shows good results in terms of both the variation and the fall time.

This shows that by inserting the lead wire terminals along the funnel shape 2, voltage is reliably applied to each lead wire terminal.

In the above embodiment, the case where aluminum is used as the bottomed open container 1 has been described, but the container is not particularly limited as long as it is made of a conductive material such as conductive resin or other metal. Further, an insulating cylinder 12 having a funnel-shaped inner surface as shown in FIG. 3 may be combined with an open bottomed cylindrical container 21 as in the conventional example. Further, the funnel-shaped portion may be made of a single material as shown in FIG. 1, or may be made of a combination of materials as shown in FIG. 3, but is not necessarily limited to the embodiment.
For example, the same effect applies to ellipsoids and polygons.

Note that forming vertical notches in the funnel-shaped portion has the advantage that the lead wires do not slip or rotate along the open end, and can be aligned smoothly and quickly.

Further, the funnel shape does not necessarily have to be formed up to the point where the bottomed open container is formed, but may be formed up to the middle.

In addition, before chemically treating the lead wire terminals, they may be cleaned to remove oil and fat, so it is necessary to provide a drainage hole for the cleaning solution in the body of the bottomed open container. The drain holes may be provided in an appropriate number, at an appropriate position, and in an appropriate shape.

[Effects of the Invention] According to the present invention, since the voltage is reliably applied to the lead wire terminal, the variation in the formation state of the dielectric oxide film is extremely small, and the leakage current drops quickly. It is possible to obtain a chemical conversion device and a chemical conversion method for lead wire terminals for capacitors.

[Brief explanation of the drawing]

Figures 1 to 3 show embodiments of the present invention, with Figure 1 being a front sectional view showing a chemical conversion device, Figure 2 being a curve diagram showing the leakage current drop characteristics of a chemically converted lead wire terminal, and Figure 3 being a curve diagram showing leakage current drop characteristics of a chemically converted lead wire terminal. 4 is a front sectional view showing another embodiment of the bottomed opening container, and FIG. 4 is a front sectional view showing a state in which a lead wire terminal is housed in the conventional bottomed opening container.

Claims (7)

[Claims] (1) A lead wire terminal with a lead wire in contact with the inner bottom surface of the bottomed open container, and an electrode jig arranged on the outer bottom surface of the bottomed open container, and this electrode jig is connected to the anode of the power source. In the chemical conversion apparatus for a lead wire terminal for an electrolytic capacitor, the aluminum flat part of the lead wire terminal is immersed in a chemical liquid to which the cathode of the power source is connected and chemically formed. 1. A chemical conversion device for lead wire terminals for electrolytic capacitors, characterized in that the bottom surface is made of a material that is conductive and magnetically permeable or contains a magnetically permeable material. (2) Claim (1) in which the bottomed open container consists of an insulating cylinder with a funnel-shaped inner surface arranged inside a bottomed metal cylindrical container.
) Chemical conversion equipment for lead wire terminals for electrolytic capacitors. (3) The chemical conversion apparatus for lead wire terminals for electrolytic capacitors according to claim (1), wherein the bottomed open container is made of metal or conductive resin. (4) The chemical conversion device for lead wire terminals for electrolytic capacitors according to any one of claims (1) to (3), wherein the inner surface of the bottomed open container is circular, elliptical, or polygonal. (5) The chemical conversion device for lead wire terminals for electrolytic capacitors according to any one of claims (1) to (4), wherein vertical notches are formed on the funnel-shaped inner surface of the bottomed open container. (6) Insert the lead wire of the lead wire terminal so that the inner surface is in contact with the inner bottom surface of the bottomed open container formed in the shape of a funnel, and then A step of holding the wire by suction, a step of immersing the aluminum flat part of this lead wire terminal in a chemical solution, and after this step, a voltage is applied from an anode connected to an electrode jig and a cathode connected to a chemical solution to lead the wire. 1. A method for forming a lead wire terminal for an electrolytic capacitor, the method comprising sequentially performing a chemical conversion treatment on the wire terminal. (7) The method for chemically forming a lead wire terminal for an electrolytic capacitor according to claim (6), wherein a bottomed open container having vertical notches formed on the funnel-shaped inner surface is used.