JP2012191020A - Metalized film capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax electric field concentration at an edge face of metal film and thereby restrict reduction in electrostatic capacitance due to separation of unit capacitors.SOLUTION: A plurality of metalized films 10, each prepared by vapor-depositing a metal film 16 on the surface of a dielectric film 12 so as to have a margin portion 14 formed along one lateral edge and also providing insulation slits 20, 24 and then forming a plurality of divided electrodes 26 on the metal film 16, are laminated one on top of another, or laminated and wound, in such a way as to have the margin portions 14 of the plurality of metalized films 10 disposed on the opposite side each other, to form a capacitor element. Also, metallicon electrodes, which will be connected to the divided electrodes 26, are formed at both ends of the capacitor element, and further a unit capacitor is composed with a pair of divided electrodes 26, 26 facing each other via the dielectric film 12. In a metalized film capacitor thus created, a gradient metal film 30 whose thickness gradually decreases toward the outside is formed on a metal film end face 16a at a position where a region functioning as the unit capacitor is formed.

Description

  The present invention relates to a metallized film capacitor formed by laminating or laminating a plurality of metallized films formed by depositing a metal film on the surface of a dielectric film, and in particular, by forming insulating slits in the metal film. Security that prevents final breakdown and ignition of metallized film capacitors by forming a split electrode and separating the split electrode from the metallicon electrode when dielectric breakdown occurs in part of the dielectric film The present invention relates to a metallized film capacitor having a mechanism.

  A metallized film capacitor using a capacitor element that is formed by laminating or winding a plurality of metallized films with a metal film deposited on the surface of a dielectric film is insulated again even if partial dielectric breakdown occurs in the capacitor element. It is widely used in various electric and electronic devices such as household electric appliances because of its excellent self-healing property.

  In recent years, when a plurality of divided electrodes are formed by forming insulating slits in the metal film of a metallized film, and a dielectric breakdown occurs in a part of the dielectric film, the divided electrode at the location of the dielectric breakdown is removed from the metallicon electrode. Metallized film capacitors having a security mechanism that prevents the ultimate destruction and ignition of the metallized film capacitor by being separated are used.

  In this type of metallized film capacitor with a security mechanism, for example, as shown in FIGS. 15 to 17, a metal film 74 is formed on the surface of the dielectric film 70 so that a margin portion 72 is formed along one side. The metallized film 76 is formed by vapor deposition, and a plurality of first insulating slits 78 are formed at predetermined intervals along one side facing the margin portion 72, and the first insulating slits 78 are formed. , 78 is formed with a fuse function part 80. Further, a plurality of divided electrodes 84 are formed by arranging a plurality of second insulating slits 82 connecting the first insulating slits 78 and the margin portion 72 at a predetermined interval.

  Thus, as shown in FIGS. 18 and 19, a pair of metallized films 76, 76 having the above-described structure are laminated or wound so that the respective margin portions 72 are arranged on the opposite side, thereby to obtain the capacitor element 86. And a metallized electrode 88 is formed by spraying an electrode material on both end faces of the capacitor element to form a metallized film capacitor 90 (FIG. 20). At this time, a unit capacitor is constituted by a pair of divided electrodes 84 and 84 facing each other through the dielectric film 70, and each divided electrode 84 and 84 is connected to the metallicon electrode 88 through the fuse function unit 80.

  In the metallized film capacitor 90 having the above-described structure, when a dielectric breakdown occurs in a part of the dielectric film 70, the metal film 74 of the fuse functional unit 80 is melted and broken by the current flowing through the divided electrodes 84 and 84 at the dielectric breakdown location. As a result, the divided electrodes 84 and 84 constituting the unit capacitor at the dielectric breakdown location are separated from the metallicon electrode 90, so that the metallized film capacitor can be prevented from being ultimately destroyed or ignited.

In addition, the metallized film capacitor of the said structure is disclosed by Unexamined-Japanese-Patent No. 2000-12368 (patent document 1), for example.
JP 2000-12368 A

When an abnormal voltage is repeatedly applied to the metallized film capacitor 90 having the above structure, the fuse function unit 80 is melted and broken in a chain, and the divided electrodes 84 and 84 constituting the unit capacitor at the dielectric breakdown point are separated from the metallized electrode 90. Therefore, although the metalized film capacitor 90 as a whole is not short-circuited, a large number of unit capacitors are separated, resulting in a significant decrease in capacitance.
Since the end face 74a (FIGS. 16 and 17) of the metal film 74 constituting the divided electrodes 84 and 84 is “substantially perpendicular” to the surface of the dielectric film 70, the division is performed when an abnormal voltage is applied. It has been found that an electric field concentrates on the end face 74a of the metal film 74 constituting the electrodes 84 and 84 to generate a discharge, which breaks the fuse function portion 80 and promotes separation of unit capacitors.

  The present invention has been made in view of the above-described conventional problems. The object of the present invention is to provide a metallization that can alleviate electric field concentration at the end face of a metal film and suppress a decrease in capacitance due to separation of unit capacitors. It is to realize a film capacitor.

In order to achieve the above object, a metallized film capacitor according to claim 1 of the present invention comprises:
A plurality of metallizations in which a metal film is deposited on the surface of the dielectric film so that a margin is formed along one side, and an insulating slit is provided to form a plurality of divided electrodes on the metal film. The film is laminated so that the margin portions of the plurality of metallized films are arranged on the opposite side, or laminated and wound to form a capacitor element, and connected to the divided electrodes on both end faces of the capacitor element A metallized film capacitor formed by forming a unit capacitor with a pair of divided electrodes facing each other via a dielectric film,
An inclined metal film whose thickness gradually decreases toward the outside is formed on the end face of the metal film where the region functioning as the unit capacitor is formed.

The metallized film capacitor according to claim 2 of the present invention is
One metallization is formed by depositing a metal film on the surface of the dielectric film so that a margin is formed along one side and providing an insulating slit to form a plurality of divided electrodes on the metal film. Capacitor element by alternately laminating or winding the film and the other metallized film formed by depositing a metal film on the surface of the dielectric film so that a margin portion is formed along one side. And a metallized electrode connected to the divided electrode of one metallized film and the metal film of the other metallized film are formed on both end faces of the capacitor element, and further facing each other through a dielectric film A metallized film capacitor comprising a unit capacitor composed of a split electrode of one metallized film and a metal film of the other metallized film,
An inclined metal film whose thickness gradually decreases toward the outside is formed on the end face of the metal film where the region functioning as the unit capacitor is formed.

The metallized film capacitor according to claim 3 of the present invention is the metallized film capacitor according to claim 1 or 2,
A fuse function part made of a metal film having a width narrower than that of the divided electrode is formed between the divided electrode and the metallicon electrode.

The metallized film capacitor according to claim 4 of the present invention is the metallized film capacitor according to any one of claims 1 to 3,
The surface of the inclined metal film is uneven.

The metallized film capacitor according to claim 5 of the present invention is the metallized film capacitor according to any one of claims 1 to 4,
A metal film end face at a position where a region functioning as a unit capacitor is formed has a curved shape, and the inclined metal film is formed on the end face of the metal film having such a curved shape.

  The metallized film capacitor according to the present invention has an abnormal voltage formed by forming an inclined metal film whose thickness gradually decreases toward the outside on the end surface 16a of the metal film at a position where a region functioning as a unit capacitor is formed. Since the electric field concentration at the end face of the metal film is alleviated when this is applied, it is possible to suppress a decrease in capacitance due to separation of the unit capacitors.

  When the surface of the inclined metal film is uneven as in the metallized film capacitor according to claim 4, the electric field can be dispersed in a large number of portions of the inclined metal film, so that the electric field concentration is reduced. be able to.

  In addition, when the metal film end face where the region functioning as the unit capacitor is formed as a “curved surface shape” as in the metallized film capacitor according to claim 5, the end face of the metal film in which electric field concentration is likely to occur. Therefore, the locations where electric field concentration occurs are dispersed, and the occurrence of discharge, which is a factor of separation of unit capacitors, can be suppressed.

1 to 4 show a first metallized film 10 constituting a metallized film capacitor according to the present invention, FIG. 1 is a plan view, and FIG. 2 is a sectional view taken along line XX of FIG. 3 is a YY sectional view of FIG. 1, and FIG. 4 is a central transverse sectional view of FIG.
The first metallized film 10 has a thickness of 10 nm to 80 nm so that a margin portion 14 is formed along one side on the surface of a dielectric film 12 made of polypropylene, polyester, or the like. It is formed by vapor deposition.

The metal film 16 is made of aluminum, zinc, zinc-aluminum alloy or the like. In the case where the metal film 16 is made of aluminum, high moisture resistance is realized, and generation of so-called “squeal” when harmonics are applied to the metallized film capacitor can be suppressed.
The “squeal” of this metallized film capacitor means that the Coulomb force acts between the electrodes when an AC voltage is applied to the capacitor, and the metallized film 10 vibrates due to the periodic change of the Coulomb force. That is, when the vibration is in the audible frequency range (20 Hz to 20 kHz), it can be heard as a beat sound.

Further, the metal film 16 on one side facing the margin portion 14 is formed with a metallicon connection portion 18 that is connected to a metallicon electrode described later.
Further, a plurality of first insulating slits 20 are formed at predetermined intervals along the metallicon connecting portion 18, and a fuse function portion 22 composed of the metal film 16 is provided between the first insulating slits 20, 20. Is formed.
A plurality of second insulating slits 24 extending in the width direction of the dielectric film 12 connecting the first insulating slits 20 and the margin portion 14 are arranged in parallel at predetermined intervals.
The first insulating slit 20 and the second insulating slit 24 are portions where the metal film 16 is not deposited.

Thus, by forming the first insulating slit 20 and the second insulating slit 24, the metal film 16 on the surface of the dielectric film 12 is formed with the first insulating slit 20 and the second insulating slit 24. A plurality of divided electrodes 26 separated and partitioned are formed. Each divided electrode 26 is connected to the metallicon connection portion 18 via the fuse function portion 22.
As shown in FIG. 1, the metal film 16 constituting the fuse function part 22 is narrower than the metal film 16 constituting the divided electrode 26.

As shown in FIGS. 5 and 6, a plurality of the first metallized films 10 and 10 are laminated or wound so that the respective margin portions 14 are arranged on the opposite side to form a capacitor element 27. The metallized film capacitor 29 of the present invention is formed by spraying an electrode material such as solder or red copper on both end faces of the capacitor element 27 to form the metallicon electrode 28 (FIG. 7).
At this time, each divided electrode 16 is connected to the metallicon electrode 28 via the metallicon connecting portion 18, and a unit capacitor is constituted by a pair of divided electrodes 26, 26 facing each other via the dielectric film 12. Become.

In the present invention, the inclined metal film 30 is formed on the end face 16a of the metal film 16 that faces the dielectric film 12 (see FIGS. 5 to 7).
That is, a region defined by the metal film 16 of the divided electrode 26 facing each other through the dielectric film 12 is a region C that functions as a unit capacitor, and the metal film at a position that forms the region C that functions as such a unit capacitor. The inclined metal film 30 is formed on the end face 16a (FIG. 7).
The inclined metal film 30 is made of the same material as the metal film 16, and has an inclined shape in which the thickness gradually decreases from the end face 16a of the metal film 16 toward the outside.

  For example, in the step of depositing the metal film 16 on the dielectric film 12, the inclined metal film 30 is deposited on the end surface 16a of the metal film 16 that forms a region functioning as a capacitor so that the amount of deposition decreases toward the outside. It is formed by conducting metal vapor. In this case, since the metal particles constituting the inclined metal film 30 are deposited more sparsely than the metal particles constituting the metal film 16, the surface of the inclined metal film 30 is uneven. In this case, when the Z portion in FIG. 1 is enlarged and observed, blurring due to the inclined metal film 30 is formed between the dark-looking metal film 16 and the bright-looking margin portion 14 as shown in FIG. Observe as.

  In the metallized film capacitor 29 according to the present invention, when an abnormal voltage is applied and a dielectric breakdown occurs in a part of the dielectric film 12, the metal of the fuse function part 22 is generated by the current flowing through the divided electrodes 26 and 26 at the dielectric breakdown location. Since the film 16 melts and breaks, and the divided electrodes 26 and 26 constituting the unit capacitor at the location of dielectric breakdown are separated from the metallicon electrode 28, the metallized film capacitor 29 can be prevented from ultimate destruction and ignition.

Thus, in the metallized film capacitor 29 of the present invention, the inclined metal whose thickness gradually decreases toward the outside on the end face 16a of the metal film 16 at the position where the region C functioning as a unit capacitor is formed. Since the film 30 is formed, the electric field concentration on the end face 16a of the metal film 16 is relaxed when an abnormal voltage is applied, and the breakage of the fuse function portion 22 is reduced. be able to.
In addition, when the surface of the inclined metal film 30 is uneven, the electric field can be dispersed in a number of locations on the inclined metal film 30, so that electric field concentration can be reduced.

FIG. 9 is an essential part enlarged plan view showing a modification of the shape of the end face 16 a of the metal film 16 constituting the first metallized film 10. That is, the shape of the end face 16a of the metal film 16 constituting the first metallized film 10 shown in FIG. 1 is a “planar shape”, but the modification of FIG. 8 forms a region C that functions as a unit capacitor. The end surface 16a of the metal film 16 at the position is formed as a “curved surface shape”, and the inclined metal film 30 whose thickness gradually decreases toward the outside is formed on the end surface 16a of the metal film 16 formed into such a curved surface shape. It has the characteristics in the point.
Thus, since the end surface 16a of the metal film 16 at the position where the region C functioning as a unit capacitor is formed has a “curved surface shape”, the distance between the end surfaces 16a of the metal film 16 where electric field concentration easily occurs is “planar shape”. Therefore, the location where the electric field concentration occurs is dispersed, and the occurrence of discharge, which is a factor of separation of the unit capacitors, can be suppressed.

In the above description, the case where the metallized film capacitor 29 is configured by laminating or winding the plurality of first metallized films 10 together is described, but the present invention is not limited to this.
That is, as shown in FIG. 10, a second metallized film 32 formed by depositing a metal film 16 on the surface of the dielectric film 12 so that a margin portion 14 is formed along one side, The first metallized film 10 is alternately laminated or laminated so that the respective margin portions 14 are arranged on the opposite side to form a capacitor element, and metallized electrodes 28 are formed on both end faces of the capacitor element. You may comprise a metallized film capacitor by forming. At this time, the divided electrode 26 of the first metallized film 10 and the metal film 16 of the second metallized film 32 are connected to the metallicon electrode (not shown).
Also in this case, as shown in FIG. 11, the metal film 16 of the split electrode 26 of the first metallized film 10 and the metal film 16 of the second metallized film 32 facing each other with the dielectric film 12 interposed therebetween. The partitioned region becomes a region C functioning as a unit capacitor, and the metal film end face 16a of the first metallized film 10 and the metal of the second metallized film 32 at a position where the region C functioning as the unit capacitor is formed. The inclined metal film 30 is formed on the film end face 16a.

FIG. 12 is a plan view showing a third metallized film 34 according to the present invention. The third metallized film 34 has a margin portion 14 on the surface of the dielectric film 12 along one side. A plurality of insulating slits 36 extending in the width direction connecting the margin portion 14 and one side opposite to the margin portion 14 are arranged in parallel at predetermined intervals. Has been.
Thus, by forming the insulating slit 36, a plurality of divided electrodes 38 separated and partitioned by the insulating slit 36 are formed on the metal film 16 on the surface of the dielectric film 12.

  In the case of the third metallized film 34, each divided electrode 38 has a structure in which the side opposite to the margin 14 side is directly connected to the metallicon electrode, and an abnormal voltage is applied. When dielectric breakdown occurs in a part of the dielectric film 12, the connection point with the metallicon electrode is broken by the current flowing through the divided electrodes 38 and 38 at the dielectric breakdown points, and the divided electrodes 38 constituting the unit capacitor at the dielectric breakdown points are formed. It is a mechanism to separate from the metallicon electrode.

  As shown in FIGS. 13 and 14, a plurality of the third metallized films 34, 34 are laminated or wound after lamination so that the respective margin portions 14 are arranged on the opposite side, thereby forming a capacitor element (not shown). In addition, a metallized film capacitor is formed by forming metallicon electrodes on both end faces of the capacitor element.

  Thus, even when the third metallized films 34, 34 are used, the regions defined by the metal film 16 of the divided electrodes 38 of the third metallized film 34 facing each other through the dielectric film 12. Is a region C functioning as a unit capacitor, and the inclined metal film 30 is formed on the metal film end face 16a at a position where the region C functioning as the unit capacitor is formed (FIG. 14).

  Even in the metallized film capacitor 29 using the third metallized films 34 and 34, the thickness gradually increases toward the outer side on the end surface 16a of the metal film 16 at the position where the region C functioning as a unit capacitor is formed. Since the sloped metal film 30 that decreases to a certain level is formed, the concentration of the electric field at the end face 16a of the metal film 16 is alleviated when an abnormal voltage is applied, and the breakage at the connection point between the divided electrode 38 and the metallized electrode is reduced. It is possible to suppress a decrease in electrostatic capacity due to the separation.

It is a top view which shows the 1st metallized film which comprises the metallized film capacitor of this invention. It is XX expanded sectional drawing of FIG. It is a YY expanded sectional view of FIG. FIG. 2 is a central cross-sectional view of FIG. 1. It is a principal part top view which shows the state which laminates | stacks a pair of 1st metallized film. It is an expanded sectional view which shows the state which laminates | stacks a pair of 1st metallized film. It is a fragmentary sectional view showing the metallized film capacitor concerning the present invention. It is explanatory drawing which shows typically the state which expanded and observed the Z section of FIG. It is a principal part enlarged plan view which shows the modification of the end surface shape of the metal film of a 1st metallization film. It is a principal part top view which shows the state which laminates | stacks a 1st metallized film and a 2nd metallized film. It is an expanded sectional view showing the state where the 1st metallized film and the 2nd metallized film are laminated. It is a top view which shows the 3rd metallized film which comprises the metallized film capacitor of this invention. It is a principal part top view which shows the state which laminates | stacks a pair of 3rd metallized film. It is an expanded sectional view showing the state where a pair of 3rd metallized films are laminated. It is a top view which shows the metallized film which comprises the conventional metallized film capacitor. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a principal part top view which shows the state which laminates | stacks a pair of conventional metallized film. It is an expanded sectional view which shows the state which laminates | stacks a pair of conventional metallized film. It is a fragmentary sectional view which shows the conventional metallized film capacitor.

10 First metallized film
12 Dielectric film
14 Margin
16 Metal film
16a End face of metal film
18 Metallicon connection
20 First insulation slit
22 Fuse function
24 Second insulation slit
26 Split electrode
27 Capacitor element
28 Metallicon electrode
29 Metallized film capacitors
30 Graded metal film C Area that functions as a unit capacitor
32 Second metallized film
34 Third metallized film
36 3rd metallized film insulation slit
38 Divided electrode of third metallized film

Claims (5)

A plurality of metallizations in which a metal film is deposited on the surface of the dielectric film so that a margin is formed along one side, and an insulating slit is provided to form a plurality of divided electrodes on the metal film. The film is laminated so that the margin portions of the plurality of metallized films are arranged on the opposite side, or laminated and wound to form a capacitor element, and connected to the divided electrodes on both end faces of the capacitor element A metallized film capacitor formed by forming a unit capacitor with a pair of divided electrodes facing each other via a dielectric film,
A metallized film capacitor, wherein an inclined metal film whose thickness gradually decreases toward the outside is formed on an end face of the metal film at a position where a region functioning as the unit capacitor is formed. One metallization is formed by depositing a metal film on the surface of the dielectric film so that a margin is formed along one side and providing an insulating slit to form a plurality of divided electrodes on the metal film. Capacitor element by alternately laminating or winding the film and the other metallized film formed by depositing a metal film on the surface of the dielectric film so that a margin portion is formed along one side. And a metallized electrode connected to the divided electrode of one metallized film and the metal film of the other metallized film are formed on both end faces of the capacitor element, and further facing each other through a dielectric film A metallized film capacitor comprising a unit capacitor composed of a split electrode of one metallized film and a metal film of the other metallized film,
A metallized film capacitor, wherein an inclined metal film whose thickness gradually decreases toward the outside is formed on an end face of the metal film at a position where a region functioning as the unit capacitor is formed.   3. The metallized film capacitor according to claim 1, wherein a fuse function part made of a metal film having a width narrower than that of the divided electrode is formed between the divided electrode and the metallicon electrode.   4. The metallized film capacitor according to claim 1, wherein the surface of the inclined metal film is uneven. The metal film end face at a position where the region functioning as a unit capacitor is formed has a curved shape, and the inclined metal film is formed on the end face of the metal film having such a curved shape. 4. The metallized film capacitor as described in any one of 4 above.

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