JP3002430U - 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 the capacitor element and is fixed to the anode foil and the cathode foil of the capacitor element and pulled out to the outside of the outer case 2 through the through hole 6 of the rubber sealing body 5, the capacitor element 3 and the rubber sealing body A fluororesin sheet 7 is disposed in contact with the terminal at least around the cathode-side terminal 4 between the fluororesin sheet 7 and the terminal 5.

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 separator paper 13 in between and impregnated with a driving electrolyte 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. Note that, in FIG. 2, the aluminum electrolytic capacitor 10 is shown in a used state, and is upside down during manufacture.

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 holding amount 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, when the electrolytic solution containing the quaternary salt as a solute as described above is used, when the 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 There was a case in which a gap was formed between the round rod portion 20 of the terminal 18 on the cathode side, which was in close contact with and penetrated, and the electrolytic solution leaked out from there.

The present invention is directed to aluminum electrolysis using a quaternary salt electrolyte solution so that the electrolyte solution does not leak 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 pulled out of the outer case through the through holes of the rubber sealing body, at least the cathode side terminal between the capacitor element and the rubber sealing body. A fluororesin sheet is arranged around the periphery of the terminal in contact with the terminal.

Further, a capacitor element obtained by winding an aluminum anode foil and a cathode foil with separator paper impregnated with a quaternary salt electrolytic solution is provided in a bottomed outer case sealed with a rubber sealing body. In an aluminum electrolytic capacitor in which the terminals 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 between the capacitor element and the rubber sealing body. A sheet made of tetrafluoroethylene resin or tetrafluoroethylene / perfluoroalkoxyethylene copolymer resin is arranged around the terminal on the cathode side in contact with the terminal.

[0010]

[Action]

 A water-repellent fluororesin sheet, such as tetrafluoroethylene resin, or tetrafluoroethylene / perfluoro, is formed around at least the negative terminal between the capacitor element impregnated with the electrolytic solution and the rubber sealing body. Since the sheet made of alkoxy ethylene copolymer resin is placed, even if the electrolyte solution oozes out on the surface of the capacitor element facing the rubber sealing body, the electrolyte solution will be around the cathode side terminal. Since it does not touch the surface of the rubber sealing body, 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 corroded.

[0011]

【Example】

 In FIG. 1, an aluminum electrolytic capacitor 1 has a capacitor element 3 which is placed inside a cylindrical outer case 2 having a bottom and is 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 fluororesin sheet 7 is arranged between the capacitor element 3 and the rubber sealing body 5. Even if the fluororesin sheet is the same as or slightly larger than the surface of the rubber sealing body 5 and is arranged over the entire surface of the rubber sealing body 5, or only around both terminals 4, especially around the terminal on the cathode side. It may be arranged. The fluororesin sheet can be, for example, tetrafluoroethylene resin (PTFE) or tetrafluoroethylene / perfluoroalkoxyethylene copolymer resin (PFA). The thickness of the fluororesin sheet is, for example, 250 μm.

The terminal 4 may be formed by piercing the terminal through the fluororesin sheet 7 without providing a hole, but a hole smaller than the diameter of the round bar portion 4a of the terminal 4 may be provided in the fluororesin sheet in advance. Through the terminal, the adhesion between the round bar of the terminal and the hole of the fluororesin sheet is better, and the electrolytic solution does not enter the gap between the round bar of the terminal and the through hole 6 of the rubber sealing body 5. It is preferable because it can prevent

The aluminum electrolytic capacitor according to the present invention (rated 10V 1800 μF, diameter 12.5 mm, height 20 mm) and the conventional product of the same rating and size are made, and the rated voltage is set at 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 a resin sheet having a thickness of 250 μm was attached. The resin sheet used had the same size as the surface of the rubber sealing body 5.

[0015]

[Table 1]

In the table, PTFE means that a tetrafluoroethylene resin sheet is used as a fluororesin sheet, and PFA means that a tetrafluoroethylene / perfluoroalkoxyethylene copolymer resin sheet is used as a fluororesin sheet. . Also, 2/200 means that electrolyte leakage was found in two of the 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.

[0018]

[Effect of device]

 According to the present invention, in an aluminum electrolytic capacitor using a quaternary salt as an electrolytic solution, the terminal is contacted with at least the periphery of the terminal on the cathode side between the capacitor element impregnated with the electrolytic solution and the rubber sealing body. Since a water-repellent fluororesin sheet such as PTFE or PFA is arranged, even if the electrolytic solution oozes out on the side of the capacitor element facing the rubber sealing body, The liquid did not adhere to the surface of the rubber sealing body, and the electrolyte that became a strong alkali near the terminal on the cathode side did not erode the round bar of the terminal on the cathode side or the through hole of the rubber sealing body, and Liquid leakage can be prevented.

Therefore, the γ-butyrolactone quaternary ammonium salt-based electrolytic solution having the highest conductivity can be used as the electrolytic solution of 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 Exterior Case 3 Capacitor Element 4 Terminal 4a Round Bar 4b CP Wire 5 Rubber Seal 6 Through Hole 7 Fluororesin Sheet

Claims (3)

[Scope of utility model registration request] 1. A capacitor element obtained by winding an aluminum anode foil and a cathode foil with separator paper impregnated with 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 drawn out of the outer case through the through holes of the rubber sealing body, at least the cathode side between the capacitor element and the rubber sealing body. An aluminum electrolytic capacitor, characterized in that a fluororesin sheet is arranged around the terminal of the terminal in contact with the terminal. 2. A capacitor element obtained by winding an aluminum anode foil and a cathode foil with separator paper impregnated with a quaternary salt electrolytic solution 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 drawn out of the outer case through the through holes of the rubber sealing body, at least the cathode side between the capacitor element and the rubber sealing body. An aluminum electrolytic capacitor, characterized in that a sheet made of tetrafluoroethylene resin is arranged around the terminal in contact with the terminal. 3. 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 drawn out of the outer case through the through holes of the rubber sealing body, at least the cathode side between the capacitor element and the rubber sealing body. An aluminum electrolytic capacitor, characterized in that a sheet made of ethylene tetrafluoride / perfluoroalkoxyethylene copolymer resin is arranged around the terminal in contact with the terminal.