JPS583371B2 - Kotaidenkaicondensano Seizouhouhou - Google Patents

Description

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

Generally, when an external lead wire is welded to the anode lead of a capacitor element in a solid electrolytic capacitor, the semiconductor layer is destroyed by sparks, thermal shock, etc., resulting in a short circuit between the cathode and anode, or an increase in leakage current. It is known that its properties are significantly impaired.

Therefore, in the past, a Teflon washer was attached to the base of the anode lead to prevent adverse effects on the semiconductor layer during welding, but the small size of the Teflon washer made it difficult to attach it to the anode lead. This method has the disadvantage of significantly reducing workability.

In view of these points, the present invention provides a method for manufacturing a solid electrolytic capacitor that can extremely easily prevent short circuits between electrodes or increases in leakage current caused by welding without adding any special work steps. , one method will be explained below.

First, as shown in Fig. 1, a metal wire having a valve action is attached as an anode to a capacitor element 1 which is made by press-molding metal powder having a valve action such as tantalum, niobium, aluminum, etc. into a cylindrical shape and sintering it. Plant it as lead 2.

After passing through an oxide layer forming step (chemical conversion step) and a semiconductor layer forming step (decomposition step), a cathode layer 1a is formed on the surface of the capacitor element 1.

Next, as shown in FIG. 2, the lower end of the first external lead wire 3 is brought into contact with the cathode layer 1a of the capacitor element 1 and connected with a connecting member such as solder.

In this state, capacitor element 1 is covered with phenol resin.
By immersing it in a liquid resin material such as epoxy resin and pulling it up, the first resin material 4 is coated on its entire circumferential surface, thereby completing the first exterior covering.

Next, as shown in FIG. 3, the free end of the second external lead wire 5, for example, the L-shaped bent portion, is crossed over the anode lead 2 and welded.

Then, only the anode lead 2 is cut from the XX portion.

Thereafter, as shown in FIG. 4, the capacitor element 1 is immersed in a liquid second resin material 6 such as epoxy resin or silicone resin and pulled up to separate the first resin material 4, the anode lead 2, and the second resin material 6. The welded portion with the external lead wire 5 is completely covered to complete the second sheathing.

It should be noted that the present invention is not limited to the above-described embodiments; for example, in addition to the dipping method, the exterior packaging may be performed by a fluid dipping method using resin powder, a thermal spraying method using a plasma jet, or the like.

As described above, according to the present invention, before welding the second external lead wire 5 to the anode lead 2, the entire circumferential surface of the capacitor element 1 is primarily covered with the first resin material. The semiconductor layer will not be destroyed by sparks generated during welding.

Moreover, since this packaging is simply separated from what was originally done all at once in the final process, it not only does not impair workability, but also because this primary packaging is performed immediately after the formation of the semiconductor layer. The hygroscopicity of the same layer can be reduced and the capacitor characteristics can be improved.

[Brief explanation of the drawing]

1 to 4 are front sectional views for explaining the method of the present invention.

Claims (1)

[Claims] 1. The first
After this step, a first covering step of covering the entire circumferential surface of the capacitor element with a first resin material; After this first covering step, a second covering step is performed on the anode lead. a step of welding the external lead wire of the anode lead, a step of removing unnecessary parts of the anode lead, and a step of welding the welded part of the anode lead and the second external lead wire and the first resin material to a second resin material after the removal step. A method for manufacturing a solid electrolytic capacitor, the method comprising: a second packaging step of completely covering the capacitor with a second packaging step.