JPH06196357A - Film capacitor - Google Patents

Abstract

PURPOSE:To obtain a film capacitor of high breakdown strength in which resin is accurately impregnated into an inner part by a method wherein at least one layer of a plurality of dielectric film layers is comprised of a nonwoven fabric. CONSTITUTION:In a film capacitor, a metallized film comprises a first dielectric film 11 whose upper surface is applied with adhesive 11a; a nonwoven fabric film 12; and a dielectric film forming an electrode 13a on a lower surface by vapor-depositing a metal on the lower surface, and the metallized film is laminated in this order. Further, a metallized film 16 comprises a dielectric film 14 whose upper surface is applied with adhesive 14a; a nonwoven fabric film 15; and a dielectric film forming an electrode 16a by vapor-depositing a metal on a lower surface, and the metallized film 16 is laminated in this order. This laminated structure is wound and impregnated with melted insulating resin, whereby the insulating resin is respectively impregnated among laminated films to obtain a film capacitor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film capacitor impregnated with an insulating resin in order to increase the breakdown voltage.

[0002]

2. Description of the Related Art Film capacitors used for high voltage applications such as flyback transformers are impregnated with a resin in order to increase the withstand voltage. An example of such a high voltage film capacitor will be described with reference to FIGS.

As is clear from FIGS. 5 and 6, in this film capacitor, a dielectric film 1 having one surface coated with an adhesive 1a, a dielectric film 2, and a dielectric film having a metal such as Al vapor-deposited on the lower surface are used. A metallized film 3 made of a body film, a dielectric film 4 having an adhesive 4a coated on the upper surface, a dielectric film 5, and a metallized film 6 having a metal such as Al deposited on the lower surface are laminated in the order shown, and wound. It is made into a cylindrical film capacitor by being turned.

Reference numerals 7a and 7b denote lead terminals, which are provided to electrically connect the electrodes 3a and 6a made of metal deposited on the metallized films 3 and 6 to the outside. In addition, as shown by the broken line in FIG.
Is attached to the electrodes formed on the metallized films 3 and 6 at the portions where the lead terminals 7a and 7b are joined. The metal foil 8 has lead terminals 7a and 7b.
It is attached to increase the bonding strength between the electrode and the electrode.

By the way, in the case of a high voltage film capacitor, after the cylindrical film capacitor is obtained as described above, the film capacitor 9 is immersed in a molten insulating resin 10 as shown in FIG. Insulating resin is impregnated into the above-mentioned laminated body to increase the withstand voltage.

[0006]

However, at present, the width of each sheet laminated in the film capacitor 9 is relatively wide as 40 mm to 60 mm, and therefore the resin is contained between the films up to the central portion in the width direction. There was a problem that it was difficult to be sufficiently impregnated. As a result, there is a drawback that the dielectric strength cannot be sufficiently increased even if the resin is impregnated.

An object of the present invention is to provide a resin capacitor impregnated type film capacitor which can surely impregnate a resin between each film and therefore has a high withstand voltage.

[0008]

The film capacitor of the present invention is a film capacitor obtained by laminating a plurality of electrodes via a plurality of elongated dielectric film layers and impregnating a resin after winding. 2. In the film capacitor, wherein at least one layer of the plurality of dielectric film layers is composed of a non-woven fabric.

[0009]

At least one of the plurality of dielectric film layers is made of a nonwoven fabric. Since the nonwoven fabric has sufficient unevenness on the surface, the resin in a molten state sufficiently penetrates into the inside between the films in which the nonwoven fabric is interposed.
Therefore, the withstand voltage can be reliably increased by impregnating the insulating resin.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be clarified by describing non-limiting examples of the present invention. FIG. 1 is a perspective view for explaining the structure of a film capacitor according to an embodiment of the present invention, and FIG. 2 is an exploded sectional view showing a laminated structure of the film capacitor.

In the film capacitor of this embodiment, the first dielectric film 1 having the adhesive 11a applied on its upper surface is used.
1, a non-woven fabric film 12, a metallized film 13 made of a dielectric film having an electrode 13a formed on the lower surface by vapor deposition of a metal, a second dielectric film 14 coated with an adhesive 14a on the upper surface, a non-woven fabric A cylindrical film capacitor is obtained by winding a laminated body in which a metallized film 16 made of a dielectric film having electrodes 16a formed by vapor-depositing a metal on the film 15 and the lower surface is laminated in this order. There is.

The electrodes 13a and 16a are provided with lead terminals 17a and 17 for electrical connection with the outside, respectively.
b is electrically connected. However, lead terminal 1
In order to enhance the bonding strength between the electrodes 7a, 17b and the electrodes 13a, 16a, a metal foil 18 is attached to the electrodes 13a, 16a at the portions where the lead terminals 17a, 17b are bonded, as shown by the broken line in FIG. ing.

The film capacitor of this embodiment is obtained by winding the above-mentioned laminated structure and immersing it in a molten insulating resin to impregnate the laminated films with the insulating resin. . The film capacitor of this example thus obtained is shown in FIG.
The film capacitor 21 has a shape in which lead terminals 17a and 17b are pulled out laterally from both end surfaces of a cylindrical wound body 21a.

In the film capacitor 21 of this embodiment,
As described above, the non-woven fabric film 12 is inserted between the first dielectric film 11 and the metallized film 13, and the non-woven fabric film 15 is similarly inserted between the second dielectric film 14 and the metallized film 16. There is.

As the non-woven fabric films 12 and 15, for example, as shown in FIG. 4 (a), non-woven fabrics 12b and 12c are bonded to both main surfaces of a dielectric film 12a, or as shown in (b), A dielectric film 12a having a non-woven fabric 12b bonded to one main surface thereof is used. As described above, in the non-woven fabric films 12 and 14, since the non-woven fabric is bonded to at least one main surface of the dielectric film, the unevenness of the non-woven fabric can surely impregnate the resin to the central portion in the width direction. That is, the resin is surely impregnated in the gap between the films indicated by the arrow A in FIG. Therefore, a high-voltage film capacitor can be obtained.

In the above-mentioned film capacitor 21, as the first and second dielectric films 11 and 14, for example, a suitable dielectric resin film such as a polyethylene terephthalate film is provided on the upper surface of a suitable acrylic adhesive or the like. The one coated with an adhesive is used. Also,
As the non-woven fabric films 12 and 15, a dielectric resin film made of polyethylene terephthalate or the like and having a polyester non-woven fabric bonded to at least one surface thereof are also used.
Alternatively, a non-woven fabric obtained by sticking polyester fibers together is used.

In the above embodiment, the non-woven fabric film 1 is used.
Examples of the reference numeral 2 and 14 are those obtained by laminating a non-woven fabric on at least one surface of the dielectric film 12a. However, as long as the non-woven fabric itself can withstand tension during winding when manufacturing a film capacitor, the dielectric It is not always necessary to support the film, and the nonwoven fabric itself may be used in place of the nonwoven fabric films 12 and 15.

Further, the portion where the non-woven fabric is interposed is not limited between the first dielectric film 11 and the metallized film 13 and between the second dielectric film 14 and the metallized film 16. For example, in the structure shown in FIGS. 1 and 2, a nonwoven fabric film is used instead of the first and second dielectric films 11 and 14, and the first and second dielectric films 11 are replaced with the nonwoven fabric films 12 and 15. , 14 may be used as the dielectric film.

However, when the resin for impregnation enters the surface of the metallized film 13 on which the electrodes 13a are formed, the heat shock property may be deteriorated, and therefore, the non-woven fabric as in the above embodiment. Film and electrode 13
It is desirable that the second dielectric film 14 be interposed between the second dielectric film 14 and a.

In the film capacitor of the present invention,
The invention is characterized in that at least one film layer that is laminated is made of a nonwoven fabric, and other configurations,
For example, as for the shape of the electrodes and the joining structure of the lead terminals, the structure of a conventionally known film capacitor can be appropriately applied, and even in that case, by interposing a non-woven fabric as at least one film layer, it is the same as the above-mentioned embodiment. The withstand voltage can be increased.

[0021]

In the film capacitor of the present invention, since at least one film layer is made of non-woven fabric,
The resin is surely impregnated into the widthwise central portion of the portion formed of the nonwoven fabric. Therefore, it is possible to provide a highly reliable film capacitor having a high breakdown voltage.

Therefore, the film capacitor of the present invention is
For example, it can be suitably used for high voltage applications such as flyback transformers.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a film capacitor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a laminated structure in a film capacitor according to an embodiment of the present invention.

FIG. 3 is an external perspective view showing the film capacitor of the embodiment.

4 (a) and 4 (b) are schematic cross-sectional views each showing a non-woven fabric film obtained by laminating a non-woven fabric on one surface of a dielectric film.

FIG. 5 is a perspective view for explaining a conventional film capacitor.

FIG. 6 is a sectional view for explaining a laminated structure of a conventional film capacitor.

FIG. 7 is a sectional view showing a process of immersing a film capacitor in a molten resin in a conventional example.

[Explanation of symbols]

 11, 14 ... First and second dielectric films 12, 15 ... Nonwoven fabric film 13, 16 ... Metallized film 13a, 16a ... Electrode

Claims (1)

[Claims] 1. A film capacitor obtained by laminating a plurality of electrodes via a plurality of elongated dielectric film layers, and impregnating a resin after winding, at least one of the plurality of dielectric film layers. A film capacitor, wherein the first layer is composed of a non-woven fabric.