JP3002432U - Aluminum electrolytic capacitor - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the electrolyte from leaking to the outside from the gap between the through hole of the rubber sealing body and the round bar of the terminal that penetrates the rubber sealing body.
To provide an aluminum electrolytic capacitor using a graded salt electrolytic solution. [Structure] A bottomed outer case 2 in which a capacitor element 3 formed by winding an aluminum anode foil and a cathode foil with separator paper impregnated with a quaternary salt electrolyte is sealed with a rubber sealing body 5. In the aluminum electrolytic capacitor 1 which is housed in and is drawn out of the outer case 2 through the through hole 6 of the rubber sealing body 5, the terminal 4 fixed to the anode foil and the cathode foil of the capacitor element is at least the terminal 4 on the cathode side. Silicon resin 7 is attached to the part pulled out from the capacitor element 3.
Has been applied.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an aluminum electrolytic capacitor.

[0002]

[Prior art]

 As shown in FIG. 2, an aluminum electrolytic capacitor 10 has a capacitor element 14 formed by winding an aluminum anode foil 11 and an aluminum cathode foil 12 with a separator paper 13 in between and impregnated with a driving electrolytic solution. After the element is housed in a bottomed outer case 15 made of aluminum having an opening on one side, a rubber sealing body 16 is placed and closed inside the opening of the outer case to seal the periphery 17 of the opening of the outer case. It has a closed structure by being processed. In FIG. 2, the aluminum electrolytic capacitor 10 is shown in a used state, and is upside down during manufacturing.

To the anode foil and the cathode foil, the haul plate portions 18a of the terminals 18 (only the terminals on the cathode side are shown in FIG. 2) are fixed by caulking or the cold weld method, and the other end of the terminals 18 is Each of them is drawn out to the outside through the through hole 19 of the rubber sealing body 16.

As an electrolyte for driving, a quaternary ammonium salt of o-phthalic acid or a quaternary ammonium salt of maleic acid is dissolved as a solute in a solvent such as γ-butyrolactone or ethylene glycol in recent years. A quaternary salt electrolyte is used.

[0005]

[Problems to be solved by the device]

 The electrolytic solution is impregnated into the capacitor element under vacuum and is retained on the rolled aluminum anode foil and cathode foil or separator paper, but the retained amount varies somewhat. If the amount of holding is large, the electrolytic solution may ooze out to the surface of the capacitor element 14 facing the rubber sealing body 16 in use, and the surface of the rubber sealing body may be wet.

In particular, in the case of using the electrolytic solution containing the quaternary salt as a solute as described above, when an electric field is applied, the terminal 18 on the cathode side enters the through hole 19 of the rubber sealing body 16 in the vicinity thereof. 21, it is known that the pH of the electrolytic solution becomes a strong alkali. Therefore, the round bar portion 20 and the rubber sealing body 16 near the terminal 18 on the cathode side entering the through hole 19 of the rubber sealing body 16 are eroded, and the through hole 19 of the rubber sealing body 16 and this In some cases, a gap was formed between the round rod portion 20 of the terminal 18 on the cathode side which was in intimate contact with and penetrated, and the electrolytic solution sometimes leaked to the outside from here.

The present invention is directed to aluminum electrolysis using a quaternary salt electrolyte solution so that the electrolyte solution does not leak to the outside between the through hole of the rubber sealing body and the round bar portion of the terminal penetrating the rubber sealing body. It is intended to provide a capacitor.

[0008]

[Means for Solving the Problems]

 A capacitor element made by winding an aluminum anode foil and a cathode foil with separator paper impregnated with a quaternary salt electrolyte is housed in a bottomed outer case sealed with a rubber sealing body, and In an aluminum electrolytic capacitor in which the terminals fixed to the anode foil and cathode foil of the element are drawn out of the outer case through the through holes of the rubber sealing body, at least the terminal on the cathode side is silicon-exposed at the location where it is pulled out from the capacitor element. It is configured such that resin is applied.

[0009]

[Action]

 Silicon resin is applied to both terminals or the terminal on the cathode side that is pulled out from the capacitor element.Therefore, the electrolyte around the terminals where the silicone resin is applied on the side facing the rubber sealing body. Therefore, the terminal on the cathode side and the rubber sealing body in the vicinity of the through hole of the rubber sealing body are not eroded.

[0010]

【Example】

 In FIG. 1, an aluminum electrolytic capacitor 1 has a capacitor element 3 which is placed in a bottomed cylindrical outer case 2 and impregnated with an electrolytic solution. The capacitor element 3 includes an aluminum anode foil and an aluminum cathode foil. Is wound around a separator paper. A terminal 4 is fixed to each of the anode foil and the cathode foil (only the terminal on the cathode side is shown in FIG. 1), the terminal 4 is pulled out from the capacitor element 3, and the round bar portion 4a of the terminal 4 is a rubber sealing body. The CP wire 4b of the terminal 4 which is penetrated through the through hole 6 and welded to the round bar portion 4a is drawn out of the outer case 2. The portion 2a of the outer case 2 near the rubber sealing body 5 is caulked to fix the rubber sealing body 5.

A silicon resin 7 is applied around the terminals 4 or the terminals where the cathode side terminals are pulled out from the capacitor element. As the silicone resin, for example, Cylmate 82-C manufactured by Toshiba Silicone, EU putty or EV putty manufactured by Fuji Polymer can be used. Silicone resin is applied by potting using a dispenser.

An aluminum electrolytic capacitor according to the present invention (rated 10V 1800μF, diameter 12.5mm, height 20mm) and a conventional product of the same rating and size are made, and the rated voltage is set to 60 ° C and humidity 95% for a time. After applying different voltage for up to 2000 hours, liquid leakage of the electrolyte between the round bar of the terminal on the cathode side and the through hole of the rubber sealing body penetrating this was confirmed with a 20x stereoscopic microscope. However, the results shown in Table 1 were obtained. The electrolytic solution was previously impregnated into the capacitor element, and then the silicone resin was applied. Silicone resin (Cylmate 82-C made by Toshiba Silicone) was applied only to the terminal side on the cathode side.

[0013]

[Table 1]

In the table, 2/200 means that electrolyte leakage was found in two of 200 aluminum electrolytic capacitors.

From these results, it can be seen that the aluminum electrolytic capacitor according to the present invention has an excellent effect on leakage of the electrolytic solution.

[0016]

[Effect of device]

 In the present invention, in an aluminum electrolytic capacitor using a quaternary salt as an electrolytic solution, silicon resin is applied to both terminals drawn out from the capacitor element impregnated with the electrolytic solution, or the terminal side on the cathode side. Therefore, the electrolyte does not ooze out around the terminals coated with silicone resin, so the electrolyte enters the gap between the through hole of the rubber sealing body and the round bar part of the terminal that penetrates it. It is possible to prevent electrolyte leakage.

Therefore, the γ-butyrolactone quaternary ammonium salt-based electrolytic solution having the highest conductivity can be used as the electrolytic solution for the aluminum electrolytic capacitor, and the secondary smoothing capacitor can be downsized.

[Brief description of drawings]

FIG. 1 is a sectional view showing a part of an aluminum electrolytic capacitor of the present invention.

FIG. 2 is a sectional view showing a part of a conventional aluminum electrolytic capacitor.

[Explanation of symbols]

 1 Aluminum Electrolytic Capacitor 2 Outer Case 3 Capacitor Element 4 Terminal 4a Round Bar 4b CP Wire 5 Rubber Seal 6 Through Hole 7 Silicon Resin

Claims (1)

[Scope of utility model registration request] 1. A capacitor element obtained by winding an aluminum anode foil and a cathode foil via separator paper and impregnating a quaternary salt electrolyte in a bottomed outer case sealed with a rubber sealing body. In an aluminum electrolytic capacitor in which the terminals, which are housed and fixed to the anode foil and cathode foil of the capacitor element, are pulled out of the outer case through the through holes of the rubber sealing body, at least the terminal on the cathode side is pulled out from the capacitor element. An aluminum electrolytic capacitor characterized in that a silicon resin is applied to the aluminum electrolytic capacitor.