JPH0513265A - Manufacture of dry capacitor - Google Patents

Abstract

PURPOSE:To make it possible to promote a mutual blocking phenomenon of films, and avoid a drop in partial discharge start voltage in an ambient temperature even when said ambient temperature is changed by laminating a pair of a single-side deposited metal film so as to produce a pair and lap-winding said two pairs so as to form a capacitor device. CONSTITUTION:Both sides 1A and 1B are corona-treated. One of a pair of films deposited with metal on the one side 1A is wound so that a capacitor device may be obtained. This capacitor device is heated and blocking-treated. More specifically, both the sides 1A and 1B are corona-treated. A pair of films 1 where a deposited metal electrode 2 is formed on one side 1A, is firmly wound, thereby consisting the capacitor device. Then, a metallicon electrode 3 is formed on the winding end face, it is heated at a temperature ranging from 70 to 120 deg.C for several hours or for some ten hours for heat treatment. This heat treatment forces the films 1 to be thermally contracted and generates a blocking phenomenon, thereby bonding the films at a margin section.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a dry type capacitor which is constructed by using a metal vapor-deposited film.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional dry capacitor,
A corona treatment is applied only to one surface 1A of the film 1 to facilitate metal vapor deposition, and then the corona treated surface 1A is subjected to metal vapor deposition to form a vapor deposition layer 2 to be an electrode. To do.

Two pieces of this film 1 are superposed and wound in multiple layers. Then, after the metallikon electrodes 3 are formed on both winding end faces, a predetermined heat treatment is performed to eliminate the air between the layers of the film 1 due to the heat shrinkage and blocking phenomenon of the film 1 to enhance the adhesion. ..

By the way, in the margin portion 4 in the capacitor having such a structure, the corona-treated surface 1A and the non-corona-treated surface 1B face each other. Therefore, even if heat treatment is performed for the blocking treatment, even if the film is sufficiently shrunk in heat, the blocking treatment is insufficient, and the adhesiveness between the films in the margin portion 4 becomes insufficient.

Therefore, when the ambient temperature changes during the process of using the capacitor, the film expands and contracts repeatedly due to the temperature change, causing peeling between the layers of the film, resulting in a decrease in the partial discharge inception voltage.

[0006]

DISCLOSURE OF THE INVENTION The present invention promotes the blocking phenomenon between films in a dry capacitor using a metal vapor-deposited film, and avoids a decrease in partial discharge inception voltage due to changes in ambient temperature. The purpose is to

[0007]

SUMMARY OF THE INVENTION According to the present invention, a capacitor element is constructed by winding a pair of films having corona treatment on both surfaces and metal vapor deposition on one surface, and heating the capacitor element. It is characterized in that the blocking process is performed by.

[Action]

When a pair of corona-treated films are wound on both sides, the corona-treated surfaces face each other at the margin. The occurrence of the blocking phenomenon on the surface subjected to corona treatment depends on the magnitude of the surface tension, and the surface tension is larger on the surface subjected to corona treatment.

Therefore, in the margin portion, the blocking phenomenon due to the heat treatment sufficiently occurs, so that the adhesion between the films in the portion is improved. Therefore, even if the ambient temperature changes, peeling between the film layers can be avoided, and a decrease in the partial discharge inception voltage can be prevented.

[0010]

EXAMPLE FIG. 1 shows an example of the present invention. In addition, the part given the same code as FIG. 3 shows the same or corresponding part. As the film 1 according to the present invention, its both sides 1
Corona treatment is applied to A and 1B. Then, metal vapor deposition is performed on one surface 1A to form a vapor deposition layer 2 to be an electrode. As the film 1, a plain type plastic film (for example, a film made of polypropylene, polyethylene, or the like) is suitable.

A pair of the films 1 is used as a device hardness (JI
A capacitor element is formed by tightly winding it so as to have a value measured by S rubber hardness meter A type) of 92 to 95. Then, after forming the metallikon electrode 3 on the winding end face,
Heat treatment is performed by heating at a temperature of from 120 ° C. to 120 ° C. for several hours to several tens of hours. Due to this heat treatment, heat shrinkage and blocking phenomenon of the film 1 occur, residual air between the film layers is eliminated, and as shown in FIG. 1, the film layers in the margin portion 4 are adhered to each other.

The easiness of the blocking phenomenon of the film 1 in the margin portion 4, that is, the magnitude of the surface tension is such that the surface subjected to the corona treatment and the surface not subjected to the treatment face each other as shown in FIG. Such a combination is 33d
In contrast to yn / cm, as in the case of the present invention, when the corona-treated surfaces face each other, it is 42 dyn / cm. It is easy to happen.

Therefore, the adhesion due to the blocking phenomenon is improved, and therefore peeling does not occur between the film layers even when the ambient temperature changes during use, which lowers the partial discharge inception voltage. Will be avoided.

Next, the test results of the capacitor of the present invention are shown in FIG. This test was conducted on a 37 μF capacitor manufactured by using a polypropylene film having a thickness of 10 μm. The conditions of the heat cycle test were that the temperature was raised from 20 ° C to 60 ° C over 1 hour, this temperature state was continued for 2 hours, and then the temperature was lowered to -20 ° C over 2 hours. The state is continued for 2 hours, and then the temperature is raised to 20 ° C. over 1 hour. This was set as one cycle, and 10 cycles were performed.

Regarding the capacitor immediately after being manufactured,
Although there was no difference in the partial discharge starting voltage between the conventional example and the embodiment of the present invention, the partial discharge starting voltage of the conventional example was almost 1 after the above heat cycle test.
However, in the case of the example of the present invention, no decrease occurred. This also confirms that peeling between the film layers did not occur according to the present invention.

In the above-mentioned embodiment, the metallicon electrode is formed and then heated for the blocking treatment. Instead of this, heating for the blocking treatment is carried out before the metallicon electrode is formed. May be.

[0017]

As described in detail above, according to the present invention, the capacitor element is formed by the corona-treated single-sided metal vapor-deposited film, which is heated to perform the blocking treatment. The adhesion is improved, and it is possible to reliably avoid a decrease in the partial discharge inception voltage.

[Brief description of drawings]

FIG. 1 is an enlarged partial sectional view showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the effect of the method of the present invention and showing the partial discharge inception voltage before and after the change of the operating atmosphere temperature.

FIG. 3 is an enlarged partial sectional view showing a conventional example.

[Explanation of symbols]

 1 Film 1A One surface of the film 1B Other surface of the film 2 Evaporated metal electrode 4 Margin part

Claims (1)

Claim: What is claimed is: 1. A corona treatment is applied to both sides of the film, and a pair of films vapor-deposited on one side of the film is wound to obtain a capacitor element. A method of manufacturing a dry type capacitor by applying.