JP2566284Y2 - Polarized electrolytic capacitors - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polar electrolytic capacitor.

[0002]

2. Description of the Related Art The anode lead-out terminal of a conventional polar electrolytic capacitor is subjected to a voltage treatment (hereinafter referred to as aging), which is a manufacturing process of the capacitor, so that a chemical conversion oxide film is formed on the aluminum surface of the anode lead-out terminal. High pressure resistance and chemical resistance are obtained. However, in the cathode lead-out terminal, even if the capacitor is aged, the applied voltage is on the negative electrode side, so that a chemical oxide film cannot be formed, and electrical withstand voltage and chemical resistance cannot be obtained.

[0003]

The surface of aluminum used for a cathode lead-out terminal of an electrolytic capacitor generally does not have a protective layer such as a chemical oxide film. Since aluminum is an amphoteric metal and is an active metal, there is a risk that when exposed to acids and alkalis in the absence of a protective layer, it erodes aluminum and impairs the airtightness of the internal electrolyte.

[0004]

The present invention solves the above-mentioned problems, and inserts a lead terminal derived from a capacitor element into an elastic sealing member, and stores the capacitor element and the elastic sealing member in a metal case. In a polar electrolytic capacitor, which is tightly closed by tightening the metal case, a cathode drawer in which an electrolytic solution containing a quaternary aluminum salt is formed in the capacitor element and a chemical conversion oxide film is formed on at least a portion in contact with the elastic sealing member insertion portion. And a polar electrolytic capacitor provided with a terminal.

[0005]

The round aluminum wire used for the cathode lead-out terminal is subjected to a wire forming process of 10 V or more in advance and is rolled as shown in FIG. 2 to obtain a round wire other than the rolled portion (b). A conversion oxide film remains on the aluminum surface of the portion (a). This terminal is connected to the cathode foil 3 of the electrolytic capacitor and used as the cathode lead-out terminal 1, and the elastic sealing body 5 is inserted therethrough.
When it is stored in the metal case 6 and sealed, the state shown in FIG.
A chemical conversion coating is placed on the boundary surface (c) of the seal obtained with the adjacent elastic sealing body 3. When a chemical conversion oxide film is present at this position, the current flowing directly into the surface of the cathode extraction terminal 1 is suppressed, the electrochemical reaction occurring on the surface (a) of the cathode extraction end surface is suppressed, and the resistance of the seal portion is improved. , Reliability is improved.

[0006] The chemical oxide film has acid resistance and alkali resistance as compared with metallic aluminum, so that the reaction product of the electrolytic solution impregnated in the electrolytic capacitor element inhibits the action of eroding aluminum, and seals are formed. The durability of the part is improved, and the reliability is improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A round aluminum raw wire is subjected to a chemical conversion treatment at 10 V or more in advance to leave a chemical oxide film on the aluminum surface of the round wire portion (a) other than the rolled portion (b) as shown in FIG.
Next, as shown in FIG. 3, the capacitor element 4 is formed by crimping and welding to the cathode foil 3, connecting the anode foil and the anode lead-out terminal 2, and winding the same through a separator.
The cathode lead-out terminal 1 derived from the capacitor element 4
Then, the anode lead-out terminal 2 is inserted into the lead-out terminal insertion hole of the elastic sealing body 5, the element is impregnated with an electrolyte containing a quaternary ammonium salt, stored in a metal case 6, and the metal case 6 is tightened. After sealing, aging was performed by applying a voltage of the positive electrode to the anode extraction terminal 2 side and applying a voltage of the negative electrode to the cathode extraction terminal 1 side.

[0008] Figure 25 shows the results of a high-temperature and humidity-proof load test at 85 ° C and 95 ° C for a conventional product having the same rating as the electrolytic capacitor of the present invention having a rating of 25 V and 2200 µF manufactured by using a primary wire formed lead rod as a cathode lead terminal. It is shown in FIG. As is clear from the test results shown in FIG. 4, the product of the present invention has improved airtightness, suppresses an increase in tan δ under a high temperature and humidity resistance load, and has improved reliability. When the above-mentioned electrolyte was an aqueous electrolyte other than the quaternary ammonium salt, no remarkable difference was observed between the conventional product and the product of the present invention.

As described above, the present invention significantly improves the electrical characteristics of the electrolytic capacitor, and has great industrial and practical value.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the electrolytic capacitor of the present invention.

FIG. 2 is a perspective view of one embodiment of a cathode lead-out terminal of the electrolytic capacitor of the present invention.

FIG. 3 is a plan view of a main part of a cathode foil and a cathode lead terminal connection of the electrolytic capacitor of the present invention.

FIG. 4 is a high-temperature and humidity-resistant load characteristic diagram comparing a product of the present invention with a conventional product.

[Explanation of symbols]

a Round portion of cathode lead terminal subjected to primary wire conversion treatment b Rolled portion of cathode lead terminal c Boundary surface between elastic sealing body and primary wire round wire portion of cathode lead terminal 1 Cathode lead terminal 2 Anode lead terminal 3 Cathode foil 4 Capacitor element

Claims (1)

(57) [Scope of request for utility model registration] 1. A polarized electrolytic capacitor comprising: a lead terminal led out from a capacitor element inserted into an elastic sealing body; the capacitor element and the elastic sealing body are housed in a metal case; and the metal case is tightly closed by sealing. A polar electrolytic capacitor comprising: the capacitor element comprising: an electrolytic solution containing a quaternary ammonium salt; and a cathode lead-out terminal having a conversion oxide film formed on at least a portion in contact with the elastic sealing member insertion portion.