JPS5918670Y2 - Electrolytic capacitor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a low impedance electrolytic capacitor in which the electrode lead-out portion of a capacitor element is improved.

Conventionally, a low impedance electrolytic capacitor constructed as shown in FIG. 1 is known.

That is, as shown in FIG. 1A, the anode foil 5 and the cathode foil 6 are shifted from each other and wound in a non-inductive manner with the electrolytic paper 10 in between, to produce the flat element 4.

Next, as shown in the opening of the figure, a plurality of flat elements 4 are stacked, and the anode foil 5 is pressed onto the anode extraction electrode plate 1, and the cathode foil 6 is pressed onto the cathode extraction electrode plate 2, and then welded or soldered 7. Connecting.

At this time, the flat element 4 is attached to both sides of the electrode plates 1 and 2, as shown in the figure, and 3 is attached to both sides of the electrode plates 1 and 2.
This is an insulating separator between the two.

In this configuration, the anode foil 5 has an oxide film formed on the foil, so when the capacitor element 4 is flattened or connected to the anode extraction electrode plate 1 by welding or the like, the oxide film may deteriorate or be damaged. When electrolytic capacitor elements 4 tend to increase leakage current, or because they are flat, when multiple electrolytic capacitor elements 4 are stacked on an electrode plate, a gap is created in the central part 4a of the element 4, increasing tan δ or impedance.
Tightening the element requires metal fittings, making the structure complicated.
It had many drawbacks, including high manufacturing costs.

The present invention eliminates the above-mentioned drawbacks, and will be explained with reference to an embodiment of the connection structure of an electrolytic capacitor element shown in FIG. Then, an electrolytic capacitor element 14 is made.

The electrode tab 8 is connected to the anode foil 5, the electrode tab 9 is connected to the cathode foil 6, and the electrode tab 8 is connected to the anode foil 5 as shown in the opening of FIG.
and 9 are pulled out in opposite directions.

Next, a plurality of electrolytic capacitor elements 14 are stacked one on top of the other so that the polarities of the electrode tabs are in the same direction, and are connected to the plate-shaped lead-out electrode plates 1 and 2, respectively.

That is, the electrode tab 8 is welded 7 to the anode extraction electrode plate 1 , and the electrode tab 9 is welded 7 to the cathode extraction electrode plate 2 .

The separator 3 is for insulating the lead electrode plates 1 and 2.

A plurality of capacitor elements 14 are connected to both sides of the extraction electrode plates 1 and 2, as shown in FIG.

In FIG. 3, the capacitor element 14 shown in FIG. 2 is connected to a pair of plate-shaped extraction electrode plates 1 and 2, and the terminal sealing plate 11
FIG. 4 is a perspective view of an electrolytic capacitor in which the electrolytic capacitor element and terminal sealing plate shown in FIG. 3 are sealed in an aluminum container 12.

That is, the present invention utilizes the principle that when n electrolytic capacitor elements are connected in parallel, the impedance of the completed electrolytic capacitor becomes l/n, ignoring the impedance of the connecting electrodes.

Next, as an example, an electrode foil with a width of 3Qmm and a length of 800mm was wound through electrolytic paper, and the rated capacitance was 1000μF.
An electrolytic capacitor element with a rated voltage of 50V was obtained, and 10 of these capacitor elements were placed on one side of two aluminum electrode plates for an anode and a cathode with an insulating separator in between, and 10 pieces were placed on the other side.
A total of 20 pieces are connected in parallel to achieve a rated capacitance of 20,000.
The electrolytic capacitor of the present invention with μF and rated voltage of 50V was manufactured and the frequency-impedance characteristics were measured.
As shown in the figure.

Furthermore, as a result of measuring the leakage current, it was found that the leakage current was 40 to 80 μA, which was less than 1/10 of the conventional one.

As is clear from FIG. 5, the impedance value at high frequencies of the product of the present invention is significantly reduced compared to the conventional product.

In addition, since the electrolytic capacitor of the present invention does not need to be wound in a non-inductive manner to form a flat element, the dimensions of both ends of the anode foil and cathode foil can be designed to be short, reducing the amount of material used. Therefore, it is easy to wind up, and processing such as flattening and tightening is not required, reducing working time and manufacturing costs by 30%.

The present invention is an electrolytic capacitor in which electrode tabs drawn out in opposite directions from multiple cylindrical capacitor elements are connected in parallel to lead-out electrode plates that form a pair like sharp parts.This reduces leakage current and reduces impedance at high frequencies. It is suitable for high-frequency circuits with large ripple current, such as switching regulators, and is inexpensive and can improve productivity, making it of great practical value.

[Brief explanation of drawings]

Figure 1 shows a conventional electrolytic capacitor; (a) is a perspective view of a flat element wound in a non-inductive (non-inductive) shape; Figures 2 to 4 show an embodiment of the electrolytic capacitor of the present invention, and Figure 2A shows the development of the electrolytic capacitor element. Perspective view, Figure 2 The opening is a perspective view of a wound cylindrical electrolytic capacitor element, Figure 2 C is a perspective view of a plurality of cylindrical elements assembled and connected to an extraction electrode plate, Figure 2 2 is a perspective view of a wound cylindrical electrolytic capacitor element. Figure 3 is a plan view of a plurality of cylindrical elements assembled and connected to a lead-out electrode plate, Figure 3 is a perspective view of the lead-out electrode plate shown in Figure 2 with a terminal sealing plate attached, and Figure 4 is the electrolysis system of the present invention. FIG. 5 is a perspective view of a capacitor, and is an impedance frequency characteristic diagram of an electrolytic capacitor showing a comparison between the product of the present invention and a conventional product.

Claims (1)

[Scope of utility model registration request] A plurality of cylindrical capacitor elements having electrode tabs drawn out in opposite directions are arranged side by side on a pair of drawn electrode plates in the length direction of the electrode plates, and each of the electrode tabs is welded to the electrode plates. An electrolytic capacitor that is connected in parallel and stored in a container.