WO1999045552A1

WO1999045552A1 - Film capacitor

Info

Publication number: WO1999045552A1
Application number: PCT/JP1999/001097
Authority: WO
Inventors: Tadashi Omura; Masaharu Morimoto
Original assignee: Sony Co., Ltd.; Shinyei Kabushiki Kaisha
Priority date: 1998-03-05
Filing date: 1999-03-05
Publication date: 1999-09-10
Also published as: JPH11251183A

Abstract

A film capacitor (10) comprises a metalized strip (11) having first dielectric film (11a) metalized for a capacitor electrode section (11b); a metalized strip (12) having first dielectric film (12a) metalized for a capacitor electrode section (12b), with its dielectric film (12a) in contact with the capacitor electrode section (11b); and a metalized strip (13) for electric discharge, having second dielectric film (13a) in contact with the capacitor electrode section (12b). These strips are together rolled into a cylinder. The metalized film (13) includes a pair of electric discharge electrodes (13b) that are isolated by an electric discharge gap (13e) for healing that is extended longitudinally in the middle of the dielectric film (13a).

Description

Film capacitor

Technical field

The present invention relates to a film capacitor formed by laminating dielectric films provided with capacitor electrode portions. Rice field

Technology background

A film capacitor used as a noise filter in an input circuit of an electronic device is usually formed by depositing a metal electrode on the surface of a strip-shaped dielectric film. It is manufactured by laminating and winding a pair of metallized films whose parts are continuously provided in the longitudinal direction in a state where the capacitor electrode parts do not face each other.

In such a film capacitor, an abnormal voltage from the outside such as dielectric lightning or line noise, or an abnormal voltage such as a surge voltage generated inside an electronic device may cause a problem. A part of the capacitor electrode in the metallized film may be damaged, and the capacitance may decrease. Moreover, Te cowpea the arc discharge by abnormal voltage, there Ri by the and this dielectric off I Lum is destroyed, dielectric breakdown occurs and also may burn the off I Rumuko capacitor itself I by the heating _c Japanese Patent Application Laid-Open No. 59-6522 discloses a filter in which an insulating groove is formed in one of a pair of metallized films in one of the capacitor electrode portions along the width direction and the longitudinal direction. Lum Condenza is disclosed. Such a finolem capacitor is a capacitor Since the electrode portion is divided in the width direction and the longitudinal direction to be in an insulated state, a plurality of pairs of series-connected capacitor elements are connected in parallel.

Such a film capacitor has excellent withstand voltage, and when a high voltage exceeding a predetermined value is applied, the capacity is reduced in a short time and the capacitor function is stopped. It has a fuse function. Therefore, when a high voltage is applied for a long time, there is no possibility that heat will be generated, and burning of the film capacitor will be prevented.

In such a finolem capacitor, the capacitor function stops due to sudden abnormal voltage such as dielectric lightning, surge voltage, etc. Cannot be used. Therefore, it may not be possible to use it stably for a long time as a noise filter in the input circuit section of the electronic device.

The present invention is intended to solve such a problem. The purpose of the present invention is to eliminate the possibility of heat generation and burning even when an abnormal voltage such as a dielectric lightning or surge voltage is applied. An object of the present invention is to provide a film capacitor that can be used stably as a noise filter for a long period of time so that the capacitor function is not impaired. Disclosure of the invention

The film capacitor of the present invention includes a pair of capacitor electrodes arranged in a stacked state via a first dielectric film, and a second dielectric capacitor stacked on one of the capacitor electrodes. Film and A pair of discharge electrode portions, each of which is stacked in an insulated state by a healing discharge gear provided on the second dielectric film. Features.

Each of the discharge electrode portions is provided with a plurality of discharge portions protruding into a healing discharge gear so as to approach each other in the longitudinal direction.

Thus, in the film capacitor of the present invention, even if an abnormal voltage is applied to the capacitor electrode portion, the abnormal voltage is discharged between the pair of discharge electrode portions, and An abnormal current does not flow between the capacitor electrodes laminated with the dielectric film interposed therebetween. Therefore, the dielectric film between the pair of capacitor electrodes is not likely to be deteriorated by the abnormal voltage due to the abnormal voltage, and the decrease in the capacitance is prevented, and the heat is generated by the heat generation. There is no danger of burning. As a result, it can be used stably for a long time as a noise filter or the like in a circuit section of an electronic device. In addition, since the dielectric film between the pair of capacitor electrodes is not likely to be broken down due to abnormal voltage discharge, the dielectric film itself can be made thinner. Thus, the size of the film capacitor itself can be reduced. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram for explaining a manufacturing process in an example of an embodiment of a capacitor part of a film capacitor according to the present invention, and FIG. 2 is a development view of the capacitor part. FIG. 3 is a cross-sectional view of a main part of the capacitor part, and FIG. 4 shows another example of the embodiment of the capacitor part in the film capacitor of the present invention. FIG. 5 is a schematic diagram for explaining a manufacturing process in another example of the embodiment of the capacitor unit in the film capacitor of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram for explaining a manufacturing process of a capacitor portion of the film capacitor of the present invention, FIG. 2 is an exploded view of the capacitor portion, and FIG. 3 is a capacitor portion of the film capacitor. It is sectional drawing of the principal part of. The capacitor section 10 has a strip-shaped capacitor having a capacitor electrode 1 lb formed in a continuous strip shape on one surface of the strip-shaped first dielectric film 11a by vapor deposition of metal. Similarly to the metallized film 11, a capacitor electrode portion formed in a continuous band shape by metal deposition on one surface of the band-shaped first dielectric film 12a. The metallized film 12 having a band shape of 12b and the second dielectric film 13a having a band shape were continuously formed by metal deposition on one surface of the film 13a. It is constituted by a discharge metallized film 13 having a pair of discharge electrodes 13 b formed in a belt shape.

Each of the metallized films 11 and 12 is placed on the capacitor electrode 11 b of one of the metallized film 11 and the second of the other metallized film 12. 1 Dielectric fins 12 a are laminated so as to face each other in the longitudinal direction, and discharge is performed on the capacitor electrode 12 b of the laminated laminated film 12. The second dielectric film 13a of the metallized film 13 faces The discharge metallized films 13 are stacked like 0. Then, a pair of metallized films 11 and 12 and a metallized film 13 for discharge are mutually laminated to form a metallized film for discharge. The film 13 is wound in a cylindrical shape so as to be wound inside, so that a capacitor portion 10 is formed. The respective metallized fins 11 and 12 and the respective metallized fins 13 are wound so that no air remains between them.

The capacitor electrode portions 11b and 12b of each metallized film 11 and 12 are connected to one side edge of the first dielectric film 11a and 12a. Each of the first dielectric fins 11 a and 12 a has a capacitor electrode portion 11 b and 12 b on one side edge thereof. The unprovided margin portions 11c and 12c are formed respectively.

Each of the metallized holograms 11 and 12 is arranged such that the respective margins 11c and 12 are located on opposite sides, respectively. Mutually in the width direction so that the side edges provided with the capacitor electrode portions 11b and 12b in the films 11 and 12 are located outside the other finolem 12 respectively. They are stacked with a slight deviation from each other.

The second dielectric film 13a in the discharge metallized film 13 is formed of a metallized film whose side edges along the longitudinal direction are laminated to each other. Each side edge located on the outside of each of the films 11 and 12 has a dimension in the width direction so as to overlap in alignment.

A pair of discharge electrodes 1 3 of the discharge metallized film 13 b is insulated from each other by the healing discharge gear 13 e continuously formed along the longitudinal direction at the center in the width direction of the second dielectric film 13 a. It is in a state. The opposing side edges of each of the discharge electrode sections 13b are comb-shaped. In other words, each discharge electrode portion 13b is located at the center in the width direction from the base portion 13 continuously laminated along the longitudinal direction on each side edge portion of the second dielectric film 13a. A plurality of discharge portions 13 d protruding into the cooling discharge gap 13 e in a rectangular shape toward the portion are provided in a row at regular intervals in the longitudinal direction. The tips of the respective discharge portions 13 d in the respective discharge electrode portions 13 b are in a state of approaching each other. The tips of a pair of discharge sections 13 d approaching each other in each discharge electrode section 13 b are in close proximity to each other by a small gap section 13 f of about several mm. It has become.

The capacitor portion 10 formed in this way is provided between the stacked capacitor electrode portions 11 b and 12 b by the first dielectric material of the metallized finolem 12. The film 12a is continuously sandwiched, the capacitor electrode portions 11b and 12b are in an insulated state, and the capacitor electrode portion 12b and the pair of discharge electrode portions 1b are insulated. The second dielectric film 13a is continuously sandwiched between the capacitor electrode portion 3b and the capacitor electrode portion 12b and each of the discharge electrode portions 13b is in an insulated state. Further, the first dielectric film 11a is continuously interposed between the pair of discharge electrodes 13b and the capacitor electrode 11b of the metallized fin 11m. The discharge electrodes 13 b are insulated from the capacitor electrodes 11 b of the metallized finolems 11. To prevent air from remaining inside, each metalized film 1

As shown schematically in Fig. 2, the capacitor section 10 in which the metallized films 1 and 12 and the discharge metallized film 13 are wound in a stacked state has tin on each end face, as schematically shown in Fig. 2. The electrode lead-out portions 14 are respectively provided by a metal alloy which is a lead alloy. The electrode lead-out part 14 provided on one end face of the capacitor part 10 is composed of the capacitor electrode part 1 lb of the metallized finolem 11 and the discharge metallizer. It is in a state of being electrically connected to one of the discharge electrodes 13 b of the discharge film 13, respectively, and is provided on the other end face of the capacitor 10. The electrode lead-out part 14 is composed of the capacitor electrode part 12 b of the metallized film 12 and the other discharge electrode part of the metallized film 13 for discharge. 1 and 3 are electrically connected. Then, a lead wire 15 is connected to each of the electrode lead-out portions 14 to form a film capacitor element.

The film capacitor element manufactured in such a manner is formed by sealing the capacitor portion 10 with a heat-resistant resin as required. It is considered a capacitor.

The film capacitor of the present invention is used, for example, as a noise absorber in a power input circuit of an electronic device. During its use, an abnormal voltage is applied between the electrode lead-out portions 14 provided at each end of the capacitor portion 10 via the respective lead wires 15. Is applied, and an abnormal voltage is applied between the capacitor electrodes 1 lb and 12 b of the capacitor section 10, the abnormal voltage is applied to each of the discharge metallized films 13. In the discharge electrode section 13b, the portion between the tips of a pair of discharge sections 13d close to each other Arc discharge occurs at the small gap 13f where the insulation resistance value has become small. In this way, when an abnormal voltage is arced between the small gaps 13 f between the tips of the pair of discharges 13 d in each discharge electrode 13 b, each discharge 13 A healing phenomenon occurs in which the tip of d partially disappears due to the discharge energy. As a result, even if an abnormal voltage is applied between the capacitor electrode sections 11b and 12b of the capacitor section 10, the abnormal voltage is maintained at the tip of the pair of discharge sections 13d due to the healing phenomenon. There is no danger that abnormal voltage will be input to the electronic equipment as it is absorbed by the disappearance of each part. Also, there is no risk that the capacitor electrode portions 1 lb and 12 b of the capacitor portion 10 and the first dielectric films 11 a and 12 a generate heat and burn out. Further, since no abnormal voltage is applied to the capacitor electrodes 11b and 12b provided on the metallized films 11 and 12, both capacitor electrodes 1 There is no danger that the first dielectric film 12a between 1b and 12b is damaged by insulation, and there is no danger that the capacitance of the capacitor section will be reduced.

In this way, the tip portions of the pair of discharge portions 13 d in the discharge electrode portion 13 b have partially disappeared due to the healing phenomenon, and furthermore, When an abnormal voltage is applied between the lead-out portions 14, an arc discharge is generated between the tip portions of the other pair of discharge portions 13 d adjacent to the pair of partially-discharged discharge portions, and healing The tip of each discharge part 13 d partially disappears due to the phenomena. Therefore, even if an abnormal voltage is frequently applied, the function of the capacitor unit 10 is not impaired, and the capacitor unit 10 can be stably used for a long period of time. The capacitor section 10 of such a capacitor has a metallized capacitor 13 for discharging the metallized capacitor 13 used in a normal capacitor. Since it is only necessary to slightly process 11 and 12, it is easy to manufacture, and it can be manufactured at low cost and is excellent in mass productivity.

As described above, each of the discharge electrode portions 13 d provided on the discharge metallized film 13 has a rectangular discharge portion 13 d having a tip portion adjacent to each other, as described above. It is not limited to a comb-like configuration provided in a row along the longitudinal direction, but in the form of a triangular comb-tooth shape in which the tips are close to each other, and a wavy shape protruding in a circular arc. Is also good. Also, each discharge electrode portion 13d does not have a discharge portion 13d protruding into the healing discharge gap 13e, and each side edge portion facing each other is straightened. It may be configured so as to face each other via a healing discharge gap 13 e having a fixed width.

The discharge metallized film 13 having the healing discharge gap 13 e formed thereon is formed by evaporating metal over the entire surface of the second dielectric film 13 a. Alternatively, it can be formed by removing a part of the deposited metal with a laser beam. In this case, the metal deposited on the second dielectric film 13a is removed in a plurality of rows along the longitudinal direction, so that a plurality of healings along the longitudinal direction are removed. The discharge gap 13 e for the switching may be formed.

FIG. 4 is a perspective view of a capacitor section 10 showing another example of the embodiment of the film capacitor of the present invention. This film capacitor is connected to the capacitor electrode 1 Id of the metallized fin. The first dielectric film 12a of the metallized film 12 is laminated on the metallized film 12, and the capacitor electrode portion of the metallized film 12 is further laminated. This is a stacked type in which a second dielectric film 13a of a discharge metallized film 13 is stacked on the substrate 12. Further, each discharge electrode 13 b of the discharge metallized metallization 13 has a fixed width direction dimension provided at the center in the width direction of the second dielectric film 13 a. The side edges facing each other are linearly formed so as to be insulated by the healing discharge gap 13e.

Also in the case of the present embodiment, even if an abnormal voltage is applied between each of the metallized films 11 and 12, the abnormal voltage is applied to the discharge metallized film 1. Arc discharge occurs between the pair of discharge electrode portions 13 b of 3, and there is no possibility that the capacitance of the capacitor portion 10 is reduced or burned out.

As shown in FIG. 5, the discharge metallized film 13 is one of a pair of stacked metallized films 11 and 12 as shown in FIG. The discharge electrode portions 13b may be stacked so as to be in contact with the first dielectric finolem 11a of the film 11.

Further, in each of the above embodiments, an example is shown in which the capacitor electrode portion and the discharge electrode portion use a metallized film formed by vapor deposition of metal. A conductive film in which the capacitor electrode portion and the discharge electrode portion are formed by bonding a metal foil may be used. Industrial applicability

As described above, in the finolem capacitor of the present invention, Even if an abnormal voltage such as a surge voltage is applied, there is no danger of overheating and burnout, and there is no possibility that the capacitor function will be impaired. It can be suitably used as an e-filter.

Claims

The scope of the claims

1. A pair of capacitor electrodes arranged in a stacked state via the first dielectric film;

A second dielectric physolem laminated on one of the capacitor electrode portions;

A pair of discharge electrode portions, each of which is stacked in an insulated state by a healing discharge gap provided on the second dielectric film;

A film capacitor characterized by having:

2. The discharge electrode sections are characterized in that a plurality of discharge sections projecting in the healing discharge gap so as to approach each other are arranged in a longitudinal direction. The film capacitor according to claim 1.