JPS5934992Y2 - electric double layer capacitor - Google Patents

Description

[Detailed description of the invention] This invention improves the sealing performance by improving the sealing part.
This invention relates to an electric double layer capacitor that improves the mechanical strength of the lead conductor and eliminates electrochemical corrosion.

An electric double layer capacitor has a structure in which a capacitor element is impregnated with an electrolytic solution, similar to the generally well-known aluminum electrolytic capacitor.

This electrolytic solution is essential for electric double layer capacitors, and loss or reduction of this electrolytic solution causes a decrease in capacitance and an increase in internal resistance.

A conventional push-button electric double layer capacitor was constructed as shown in FIG.

That is, a capacitor element 1 impregnated with an electrolytic solution is housed in a metal case 2 such as aluminum, and a lead portion formed by connecting an outer conductor 4 to two inner conductors 3 drawn out from the capacitor element 1 is passed through the capacitor element 1. An elastic sealing body 5 made of rubber or the like is fitted into the opening of the metal case 2, and sealed by the drawing force Loe part 6 on the side of the metal case 2 and the curling force Nikko part γ at the opening end of the metal case 2, and the metal case 2 is sealed. A Wz-covered tube 8 was placed on the outer surface of the tube 2.

In such a configuration, it is difficult to completely fix the lead part due to the characteristics of the elastic sealing body 5, and when external mechanical stress is applied to the lead part, it is transmitted to the inside of the capacitor element 1, and the electrode Since carbon is used as a sealant, mechanical stress may be applied to this carbon, causing it to break and cause significant deterioration of its properties, or the sealing ability to be slightly weakened due to the infiltration of chlorinated organic solvents used as solder paste detergents. There were some drawbacks.

For this reason, as shown in FIG. 2, a structure may be adopted in which the covering tube 8 is made to protrude long in front of the sealing part of the metal case 2, and the front end of the covering tube 8 is filled with sealing resin 9 and solidified. It is being considered.

By adopting this structure, the strength of the lead portion against mechanical stress was greatly improved, but the capacitor element 1
Mechanical stress in the direction of pushing to the side [i] turned out to be surprisingly weak.

Further, in a high temperature life test under voltage application, the joint between the internal conductor 3 and the external conductor 4 corroded and was on the verge of disconnection.

This is because the inner conductor 3 is usually made of aluminum and the outer conductor 4 is made of tin-coated copper or tin-coated iron core steel, so the metal is electrolytically dissolved by the electrolyte that adheres to these parts.
The result was

The present invention eliminates the above-mentioned drawbacks of the prior art.

Hereinafter, an embodiment of the present invention will be explained with reference to FIG. 3 of the drawing.

10 is a metal case made of aluminum or the like, and inside this metal case 10 is a capacitor element 1 impregnated with an electrolyte.
1 is stored.

This capacitor element 11 has a structure in which an electrode made of carbon or the like is provided on at least one of current collectors such as aluminum, and an electrolytic solution is interposed between the current collectors.

Then, an internal conductor 12 made of two pieces of aluminum or the like is drawn out from this capacitor element 11, and this internal conductor 12
An external conductor 13 made of tin-coated copper or tin-coated iron core steel is connected to the tip by welding or the like to form a lead portion.

Then, an elastic sealing body 14 made of rubber or the like, which is penetrated through the lead part, is attached to the opening of the metal case 10, and then the squeezing force loe part 15 on the side surface of the metal case 10 is connected to the metal case 1.
It is sealed by a curling process part 16 at the open end of 0.

A joint portion between the inner conductor 12 and the outer conductor 13 protrudes from the front surface of the elastic sealing body 14.

Further, a d-dffl tube 11 is placed over the outer periphery of the metal case 10, and the lead portion side of this covering tube 1T extends long forward.

The front end of the covering tube 1γ is filled with a sealing resin 18 such as epoxy and solidified.

The sealing resin 18 contains the inner conductor 12 and the outer conductor 1.
3 joints are buried.

With this configuration, the covering tube 1γ and the sealing resin 18 are bonded together, the open end of the metal case 10 and the sealing resin 18 are bonded, and the inside of the aluminum generated when the inner conductor 12 and the outer conductor 13 are bonded is bonded to each other. conductor 12
Since side bulges, deformations, and burrs bite into the sealing resin 18, even if a large mechanical stress is applied to the lead portion from the outside, it will not be applied to the capacitor element 111.

Next, the conventional example shown in Fig. 1 and the proposed study shown in Fig. 2,
The rating of the example of the present invention shown in FIG. 3 is 1.6V.

A 10F, 12.5φ x 35mm electric double layer capacitor was manufactured, and the capacitance change rate after 250 hours after applying the rated voltage under the conditions of 85℃ and 85 to 90% RH and the rate of capacitance change at the conductor junction. The results of condition tests are shown in the table below.As the electric double layer capacitor of the present invention is constructed as described above, even if external mechanical stress is applied to the lead part, it will be absorbed by the sealing part and % by the sealing resin part. There is no possibility that the capacitor element will be damaged and its characteristics will not deteriorate, and the joint between the internal conductor and external conductor as a lead part is buried in the sealing resin. It has the advantage of being able to prevent corrosion caused by electrolyte, eliminating disconnection of the external conductor, making it highly reliable, and improving characteristics, making it a dog of practical value. be.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional electric layer capacitor;
The figure is a cross-sectional view of a conventional improvement plan, and FIG. 3 is a cross-sectional view showing an embodiment of the electric double layer capacitor of the present invention. 10... Metal case, 11... Capacitor element, 1
2... Internal conductor, 13... Outer conductor, 14... Elastic sealing body, 15... Drawing processing section, 16... Curling processing section, 17... Covering tube, 18... Sealing resin.

Claims (1)

[Scope of utility model registration request] A capacitor element impregnated with electrolyte is housed in a metal case, an outer conductor is connected to an inner conductor drawn out from the capacitor element to form a lead part, and an elastic sealing body penetrated through this lead part is used as an opening in the metal case. In an electric double layer capacitor in which a metal case is sealed and a covering tube is placed over the metal case, an end of the covering tube is made to protrude toward the lead part, and a joint between the inner conductor and the outer conductor is provided at the protruding part of the covering tube. An electric double layer capacitor filled with sealing resin to bury it.