JPS5911611A - Metallized film condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The F3A relates to improvements in metallized film capacitors.

Conventionally, metallized film capacitors, which are made by laminating or winding a double-sided aluminum metallized film and a laminated film, utilize the properties of glass film and have the unique self-healing properties of the metallized layer, making them a high-voltage capacitor. has been put into practical use as a wide range of capacitors, but in order to obtain a capacitor with a higher withstand voltage and a higher potential gradient design, it is necessary to reduce the withstand voltage drop due to minute partial discharges that occur between laminated or wound layers, and to reduce the capacitor's lifespan. Capacity reduction was a major problem.

From research on the minute partial discharges occurring between the layers, the idea has been proposed that the minute partial discharges between the layers are significantly reduced in capacitors in which double-sided metallized films are wound one on top of the other. However, in the conventional structure in which double-sided metallized films are stacked, although micro partial discharges between layers can be sufficiently suppressed, the metallized electrode layer has a double structure, and the self-discharge characteristic of the metalized electrode layer This had the disadvantage that the recovery performance deteriorated and the capacitor withstand voltage was not sufficiently improved.

In view of the above drawbacks, the inventor has developed a double-sided aluminum metallized film and a laminated film with a width slightly narrower than the stiffness.
By laminating and winding a laminated film with a zinc metallized layer having a sheet resistance value of 20 to 200Ω, interlayer micro partial discharges can be significantly reduced, and high withstand voltage can be achieved without deteriorating self-healing performance. The present inventors have discovered that it is possible to provide a metallized film capacitor that achieves this and also exhibits an extremely small decrease in capacitor capacity over its lifetime.

The configuration of the present invention will be explained in detail below along with drawings of embodiments.
Explain to Ia. FIG. 1 is a sectional view of one configuration example of a capacitor of the present invention.

In the figure, 1 is a double-sided aluminum metallized film, 2
3 is a metal sprayed part for leading out the electrodes.

On the front and back surfaces of the laminated film 2, the strip-shaped non-metalized surface 4 side of the overlapping double-sided aluminum metalized film 1 similarly has a strip-shaped non-metalized surface 5, and a zinc metalized layer 6 having a sheet resistance of 20 to 200 Ω. It is configured with the following. 7 is an aluminum metallization layer.

FIG. 2 also shows a cross-sectional view of an example of the structure of a capacitor according to the present invention. Double-sided aluminum metallized film 8 and 2
A metal sprayed portion 1o for leading out the electrode is provided by laminating or winding a laminated film 9 comprising a zinc metal layer having a sheet resistance value of 7.0 to 200Ω. The difference from the configuration in Figure 1 is that the aluminum metallized layer of the heavy double-sided aluminum metallized film also has a zinc metallized layer on the edge of the laminated film surface on the end side where it connects to the metal sprayed part for electrode lead-out. The structure is otherwise the same as the structure shown in FIG. 1 except that it has no band-shaped non-metalized surface.

If the sheet resistance value of the zinc metallized layer of the laminated film in the above structure is less than 20Ω, the self-healing function will be significantly reduced due to the two-layer electrode structure, and the capacitor breakdown voltage will not be sufficiently improved. It is possible that Moreover, if the number exceeds 2,000, it is difficult to achieve the purpose of suppressing interlayer minute partial discharge by using a two-layer electrode, and it is considered that the capacity decrease during life becomes large. It is conceivable to form the metallized layer of the double-sided aluminum metallized film with zinc metal, but considering that zinc has poorer thermal conductivity than aluminum, unlike the configuration of the present invention, the heat generation inside the capacitor is transferred to the electrode. It is inferior in heat dissipation to the surroundings through the layer, thermal breakdown occurs at high potential gradients, and it is considered that the capacitor has lower withstand voltage and quality than the capacitor of the present invention.

Next, the effects of the present invention will be specifically explained with reference to Examples.

Example 1: A 6 μm double-sided aluminum metallized polyethylene terephthalate film and a 6 μm thick polypropylene film on which a zinc metallized layer with a sheet resistance of 20 to 200 Ω was formed by true-wall zinc evaporation were combined as shown in Figure 1. A capacitor A of 4.5 μF was manufactured by laminated winding as shown in the figure.

As comparative capacitor B, the same 6 μm thick double-sided aluminum metallized polyethylene terephthalate film,
A laminated winding f-4.5 μF capacitor B was manufactured using a 6 μm thick polypropylene film without a metallized layer as a laminated film. In addition, as a comparative capacitor C, a double-sided aluminum metalized polyethylene terephthalate film with a thickness of 6 μm and a polypropylene film with a thickness of 6 μm on which an aluminum metal layer with a sheet resistance of 20 to 100 Ω was formed by vacuum evaporation were used as a laminated film.
``I manufactured a capacitor C of 4 or 5 μF with layered winding.

The results shown in FIGS. 3 and 4 were obtained. , Figure 3 is
This is the result of the relationship between the applied voltage and the breakdown time (V- is the characteristic) when the voltage is continuously applied at 70°C.

In the figure, character indicates the gv- characteristic of the capacitor of the present invention in the above embodiment, C represents the comparative capacitor C, and B represents the gv- of the comparative capacitor B. From this, it is clear that the breakdown voltage of the capacitor of the present invention and the comparison capacitor C are significantly improved. Next, FIG. 4 shows the result of capacitor capacitance reduction when 360V was applied for a continuous life. In the figure, human is the n characteristic of capacitor A of the present invention, and C is the n characteristic of capacitor C for comparison. Therefore, from this result, it can be seen that although the breakdown voltage of the comparative capacitor C is improved, the capacitance decreases greatly during its life, and it is not a high-quality high-potential gradient design capacitor.

As described above, the present invention provides a stable quality high-potential design capacitor with less capacitance loss during service life by using a film having a zinc metal layer with a sheet resistance of 20 to 200 Ω as a laminated film. It has great industrial potential, as it makes full use of the self-healing characteristics unique to metallized electrodes, making high-voltage capacitors smaller and cheaper.

[Brief explanation of drawings]

1 and 2 are sectional views of each embodiment of the metallized film capacitor according to the present invention, and FIG. 3 is a characteristic diagram of the reduction rate of the present invention. 1.8... Double-sided aluminum metallized film,
2.9... laminated film, 3,1o...
・Metal sprayed part for electrode lead-out, 4, 5... Band-shaped non-metalized surface, 6... Zinc metallized layer, 7...
Aluminum metallization layer. Name of agent: Patent attorney Toshio Nakao? Hill or 14th 1 Figure 8 + 4 skin Long time agony (so) Figure life 4 slander time (shouting order

Claims (1)

[Claims] A double-sided aluminum metallized film having a strip-shaped non-metallized surface on opposite ends of the front and back surfaces, and a strip-shaped non-metalized surface side of the double-sided aluminum metalized film that overlaps at least the front and back surfaces is a strip-shaped non-metalized layer without a metallized layer. A metallized film capacitor formed by laminating or winding a laminated film with a zinc metallized layer having a sheet resistance of 20 to 200 Ω and a non-metalized surface.