JPH02215114A - Metallized plastic film capacitor - Google Patents

Abstract

PURPOSE:To prevent the generation of a needle-electrode on a metal electrode layer by a method wherein a metallicon layer is formed on both edge faces of a capacitor element on which a pair of one-side metallized plastic films are wound around by shifting with each other. CONSTITUTION:An edge part metal layer 2 and a non-vapor deposition part 3 are formed on a metallized polyethylene terephthalate(MPET) film 1, two sheets of the above-mentioned MPET films are formed in a pair, and a capacitor element is formed by winding around the pair of films in such a manner that they are shifted with each other. At this time, an exposed part 4 is formed on the film surface by removing the metal layer at the starting end of winding and the finishing end of winding. A metallicon layer 6 is formed by frame- spraying Zn on both edge surfaces of the capacitor element 5 which is constituted as above-mentioned, and after a lead wire 7 has been connected thereto, a resin sheathing operation is conducted. Through these procedures, the generation of a needle-electrode on the metallized electrode layer can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to metallized plastic film capacitors, particularly those that prevent corona discharge, destruction, and ignition.

(Prior Art) Conventionally, as described in Japanese Patent Publication No. 56-20686, a metallized layer is formed along the edge of a film, and a metallized layer is formed via this metallized layer and a non-metalized surface. A structure in which a double-sided metallized dielectric layer having an electrode layer on each side is used, and this double-sided metallized M'R body layer and a non-metalized dielectric layer stacked to cover the non-metalized surface are wound. There is something that consists of.

In such a capacitor, it has been described that when forming an electrode lead-out part with metallicon, the metallicon metal pierces the non-evaporated part to form a needle-like electrode and prevent corona discharge. The condition is that in the construction the non-metallized dielectric covers the non-metalized side of the double-sided metallized dielectric layer. However, since the non-metalized layer width of the double-sided metallized dielectric layer is narrow, the non-metalized dielectric may not be able to reliably cover the non-metalized surface due to misalignment during winding. There was a problem in that electric charges were concentrated on the needle-like electrodes and corona discharge occurred, leading to further deterioration of the dielectric. In particular, film capacitors connected in parallel with a power supply have a small power supply impedance, so destruction progresses rapidly and a large current is supplied, leading to the risk of heat generation, smoke generation, or fire.

(Problems to be Solved by the Invention) In the technique described in Japanese Patent Publication No. 56-20686, when the non-metalized dielectric layer is displaced, the metallicon metal invades and a needle-like electrode is formed on the non-evaporated surface. Concentration of charge occurs, causing corona discharge and leading to dielectric deterioration. In addition, in a structure in which two single-sided metalized films with a non-steamed part at one end are wound in a staggered manner, if the dielectric breaks down, the deterioration of the dielectric begins at that part. proceed. In particular, when used across the line, which is connected in parallel to a power source, the line may cause a fire or the like.

The present invention is intended to solve the above-mentioned problems, and aims to prevent the formation of needle-like electrodes, deterioration of the dielectric, destruction and ignition of the capacitor, and the like.

[Structure J of the Invention (Means for Solving the Problems) The metallized plastic film capacitor according to the present invention includes an edge metal layer provided along the edge of the plastic film, and a non-evaporated portion between the edge metal layer and the edge metal layer. A capacitor element is formed by winding a pair of single-sided metallized plastic films with a metalized electrode layer formed thereon, with the metal layer removed at the beginning and end of the winding, and a metallized electrode layer formed on both end faces of the capacitor element. It consists of a metallicon layer formed.

Alternatively, a non-evaporated portion may be provided to divide the metalized electrode layer of the single-sided metalized plastic film in the length direction, and the metalized electrode layer may be made into an island shape, but the other structure may be the same as that of the metalized plastic film capacitor described above. good.

(Function) The metallized plastic film capacitor according to the present invention has a metallized plastic film capacitor that has a metallized plastic film capacitor that is
The sprayed metallicon metal is blocked by the edge metal layer and does not evaporate! ! do not form a needle-like electrode. therefore,
Since charge concentration does not occur and corona discharge is less likely to occur at low voltages, the insulation resistance value of the capacitor and the insulating liquid III! This has the advantage of reducing variations in voltage values.

In addition, when using a single-sided metalized plastic film consisting of an island-shaped metalized electrode layer with non-deposited parts that divide the metalized electrode layer in the length direction, variations in breakdown voltage and insulation resistance values can be reduced. In addition, since the breakdown occurs only partially, there is little deterioration of the dielectric material, which improves safety.

(Example) Emperor Tomoyo” As shown in Figures 1 and 2, thickness 9μm x width 20a
A metalized polyethylene terephthalate (MPET) film 1 having a thickness of 0.5 am is formed with an end gold HhII 2 having a width of 0.5 am and a non-evaporated part 3 having a width of 2 shoes, and two such MPET films are made into a pair and are separated by 0.5 am from each other. As shown in FIG. 3, the metal layer at the beginning and end of the winding is removed to form an exposed portion 4 on the film surface. Zn was thermally sprayed on both end faces of the capacitor element 5 thus constructed to form a metallicon layer 6, lead wires 7 were connected, and then resin exterior was applied.

The results of measuring insulation resistance by applying 500 VDC to the capacitor thus produced are shown in FIG. In addition, the conventional example used the same MPET film, but did not provide an end metal layer and did not expose the film surface at the beginning and end of the 9th roll, and simply formed a non-evaporated part at one end of the MPET. It is composed of
The rest was constructed under the same conditions as in the example.

As is clear from this result, the variation in insulation resistance is smaller in the example, but this is because the metallized metal layer is blocked by the end metal layer and cannot penetrate into the non-deposited area, thus preventing the formation of needle electrodes. Therefore, the lines of electric force between the vapor deposition parts become parallel.

Example 2 Figure 5 shows an MPETr with a thickness of 4f1m and a width of 1511II.
The measurement of the insulation resistance value of the conventional example (250V
(DC application) results are shown.

It is clear that, as in Example 1, the variation in insulation resistance is reduced.

[Effects of the Invention] According to the present invention, since the metallicon layer is formed on the end metal layer, it is possible to prevent the formation of needle electrodes on the metallized electrode layer, and this has the effect of reducing the breakdown voltage and insulation resistance of the capacitor. be.

[Brief explanation of the drawing]

1 and 2 are a plan view and a cross-sectional view, respectively, showing the MPET film used in the metallized plastic film capacitor according to the present invention, and FIG. 3 is an exploded perspective view showing an element of the metallized plastic film capacitor according to the present invention. 4 and 5 are graphs showing the insulation resistance values of capacitors, respectively. 1...MPET film 2...End stand RWI3...Non-evaporated part 4...
...Exposed part 5...Capacitor element 6...
...Metallicon layer 7...Lead wire patent application Hito Marukon Electronics Co., Ltd. Conventional Example 2 Fig. Conventional Example 1 Fig.

Claims (1)

[Claims] (1) Consisting of an end metal layer provided along the edge of the plastic film and a metalized electrode layer formed via the end metal layer and a non-evaporated part, the metal layer is at the start and end of the winding. A capacitor element formed by winding a pair of single-sided metallized plastic films with an offset from each other;
This is a metallized plastic film capacitor consisting of a metallicon layer formed on both end faces of this capacitor element.