JPH10326720A - Metallized film capacitor and manufacture of metallized film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of a metallized film capacitor and a metallized film, on which self-generated heat can be suppressed by lowering the tan δ of the capacitor, and safety can be improved. SOLUTION: A vapor-deposited film 1a, in which a top of corrugating sheet, having periodically increased thickness in winding direction of film or in longitudinal direction is provided, is wound or laminated on the main electrode part of the vapor-deposited film 1a in this film capacitor. The film capacitor is formed by arranging a furnace 14 in a transmission roller 16, on which small holes are periodically provided, for formation of the top of corrugating sheet 9, having periodically increased thickness, on the main electrode part, and the top of corrugating sheet of the vapor deposited film is formed by rotating the transmission roller when vapor deposition operation is conducted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a capacitor using a metallized film.
The present invention relates to a highly productive metallized film capacitor that contributes to weight reduction and a method for manufacturing a metallized film.

[0002]

2. Description of the Related Art In recent years, capacitors have been required to generate as little self-heating as possible because the density of devices in which the capacitors are mounted has increased and the influence of heat of the capacitors has been increased. On the other hand, as metallized film capacitors are required to be small and have good storage capacity for devices, various methods of using thin film with a higher voltage per thickness (improving potential gradient) have been proposed. Have been. For example, to improve the potential gradient,
It is necessary to increase the withstand voltage of the metallized film,
For that purpose, the energy at the time of self-healing when dielectric breakdown occurs in the film is reduced by reducing the vapor deposition thickness of the vaporized part of the metallized film on the opposing part, so that a continuous short circuit failure does not occur. Thus, the withstand voltage has been improved (see Japanese Patent No. 1667382).

[0003] The configuration and effects of a conventional metallized film capacitor will be described below with reference to FIG. The vapor-deposited films of the vapor deposition film 1 facing each other are formed by vapor-depositing zinc or an alloy of zinc-aluminum, and the thickness of the film is generally specified by a resistance value. The coupling portion 8b with 2 is set to 2 to 6 Ω / □. Therefore, the deposition thickness of the metallized film 1 is 2 to 6Ω.
Main electrode part 1 opposed to /
As for the energy at the time of the breakdown in a, the amount of the deposited metal to be dissolved becomes smaller by the film thickness, the self-healing property becomes easy, and the continuous breakdown does not occur. Therefore, the potential gradient of the vapor deposition film can be improved, and the characteristics can be secured with a thin film vapor deposition film even with a capacitor having the same voltage. Similarly, when the resistance value is set to 7 to 20 Ω / □, the resistance at the contact portion between the metallicon 2 and the vapor deposition film 1 increases, and heat is generated at that portion. . For this purpose, a vapor deposition film is vapor-deposited in a stepped shape as described above. FIG. 10 shows a conventional method for manufacturing a metallized film. The film 12 is cooled on a cooling scan (cooling roller) 13 by a furnace 14 as an evaporation source.
Film (metallized film)
1 was the production method completed.

[0004]

However, in the structure of the conventional metallized film capacitor, the heat generated by the current flowing through the vapor-deposited metal of the vapor-deposited film increases in order to reduce the thickness of the vapor-deposited film on the main electrode portion 8a. The fever itself increased. For this reason, a capacitor having a large capacitance was used only in a place where the ambient temperature of the equipment used was low. That is, when the current flowing through the capacitor flows through the vapor-deposited film, the resistance value is high because the vapor-deposited film is thin, Joule heat is generated, and self-heating of the capacitor itself is increased. As the temperature of the film increases, the withstand voltage characteristics of the film deteriorate, so that the withstand voltage of the capacitor itself decreases, which may lead to destruction. Recently, there is also a metallized film capacitor with a self-protection mechanism that has a fuse on the metallized film, and the heat generated in the fuse section is also increasing, and the heat inside the capacitor tends to increase, increasing the withstand voltage and safety. There is a tendency that the direction is opposite to the direction in which heat is suppressed.

An object of the present invention is to provide a metallized film capacitor having high withstand voltage characteristics and high safety while suppressing self-heating of the capacitor.

[0006]

In order to achieve the above object, a metallized film capacitor according to the present invention is characterized in that the thickness of a vapor-deposited film of a main electrode portion facing a vapor-deposited film is periodically rolled or longitudinally wound in the film. In this case, a vapor deposition film having a thick crest portion is used. Further, the method for producing a metallized film of the present invention includes the steps of: forming a periodic crest portion in a vapor deposition film; forming a vapor deposition source in a cylindrical transmission roller in which small holes are periodically arranged on a circumferential curved surface. A furnace is provided, and at the time of metal deposition of the film, the transmission roller is rotated to form a crest portion on the deposited film.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The metallized film capacitor of the present invention uses a vapor-deposited film in which a crest portion where the thickness of a vapor-deposited film of a main electrode portion facing the vapor-deposited film is thick is formed by winding the film or periodically in the longitudinal direction. This has the effect of improving the flow of current and suppressing heat generation inside the capacitor by the crest portion where the thickness of the vapor deposition film of the opposing main electrode portion is large.

In the method for manufacturing a metallized film according to the present invention, a crest portion is periodically formed in a vapor deposition film of a main electrode portion. Arranging a furnace of the evaporation source in the transmission roller, during the film deposition, while rotating the transmission roller, periodically crest portion is deposited on the deposition film, characterized in that,
It has the function of periodically changing the thickness of the deposited film in the longitudinal direction of the film.

FIG. 1 shows an embodiment of the present invention.
A description will be given with reference to FIGS.

(Embodiment 1) FIGS. 1A and 1B show Embodiment 1 of the present invention. Zinc is vapor-deposited on one side of the polypropylene film 6 having a thickness of 6 μm. The thickness of the deposited metal is 2 to 2
6Ω / □, and the main electrode portion 8 facing each electrode is 7 to 2
In the longitudinal direction of the film, a vapor-deposited film 1a provided with a crest portion 9 having a thick vapor-deposited film having a thickness of 2 to 6Ω / □ is wound in the longitudinal direction of the film to form a 60 μF element. Thereafter, as shown in FIG. 2, a metallicon 2 for leading out an electrode is applied, and as shown in FIG.
After attaching to the resin case 4, the epoxy resin 5
Is cast-hardened to complete a metallized film capacitor.

The self-heating of the capacitor is caused by the loss characteristic ta.
Since it is proportional to the value of nδ, the degree of heat generation can be determined by evaluating the value of tanδ. That is, when compared with the conventional stepped vapor deposition product shown in FIG. 9 using the same film material, the tan δ of the product of the present invention is 0.03%, while the tan δ of the conventional product is 0.06%.
And lower values. Furthermore, comparing the self-heating of the element center part of this capacitor, when applying 400 V, the heating at room temperature is 15 deg in the conventional product and 7 d in the present invention.
eg low value. This has the effect of improving the current flow by periodically increasing the film thickness. In addition,
The breakdown voltage of the capacitor was 10 va as shown in FIG.
Even when compared in the c / sec step-up breakdown test, the average is about 1400 vac, which is almost the same as the conventional one, and the first embodiment makes it possible to suppress self-heating without lowering the withstand voltage.

(Embodiment 2) Next, as shown in FIG. 4, in a vapor deposition film 1b, a crest portion 9 having a large vapor deposition thickness periodically overlaps with the winding or longitudinal direction of the film at the opposing main electrode portion. Using a vapor-deposited film that has been vapor-deposited, winding or laminating the same to form a capacitor having the same specifications as in Embodiment 1, and performing the same test as in Embodiment 1,
When the breakdown voltage is determined, the variation in the breakdown voltage is further reduced as shown in FIG. 10, and the metallized film capacitor using a vapor-deposited film in which the crest portion having a larger vapor deposition thickness overlaps with the main electrode portion facing each other. On the other hand, it became a metallized film capacitor with a more stable breakdown level. When the crests where the thickness of the vapor-deposited film is thick are facing each other as electrodes, micro-destruction at that part will increase the energy at the time of self-recovery and cause large damage to the film. However, if one of the vapor-deposited films is thin, self-recovery becomes easy and the withstand voltage does not decrease.

(Embodiment 3) FIG. 5 shows a metallized film capacitor with a self-protection mechanism according to the present invention.
2 shows a capacitor using the same. When a capacitor having the same specification as that of the first embodiment is manufactured and compared with a capacitor using a conventional film with a self-protection function, the value of tan δ is 0.07% for the conventional product and 0.04% for the product of the present invention. %, And the effect of the crest portion 9 having a thick deposition film periodically appears.

(Embodiment 4) Next, as a method of manufacturing a metallized film of the present invention, a method of winding or periodically changing a resistance value in a longitudinal direction will be described with reference to FIG. As shown in FIG. 7, the method of the present invention employs a deposition source furnace 1.
The vaporized metal from 4 is vapor-deposited on the film 12 through a transmission roller 16 rotating around a furnace 14 of the vapor deposition source so that the vapor-deposited metal is transmitted therethrough. As shown in FIG. 8, the transmission roller 16 has small holes 17 periodically arranged on a circumferentially curved surface. The crest portion 9 for increasing the film thickness of the vapor deposition film 1a is to be vapor-deposited periodically by rotating the transmission roller 16 when the film 12 is vapor-deposited. In order to prevent the small holes 17 from being clogged during the vapor deposition, an oil tank 18 is provided so that the inside of the transmission roller 16 is exposed to oil vapor in a process portion before the vapor deposition. This prevents oil from adhering to the inside of the transmissive roller 16, and allows the vapor deposition metal not to adhere to the transmissive roller 16, thereby enabling continuous vapor deposition.

[0015]

As described above, the metallized film capacitor of the present invention uses a metallized film in which the thickness of the main electrode of the vapor deposition film is periodically increased to form a crest portion. It is possible to improve the capacitor characteristics by suppressing self-heating. In addition, the method for producing a metallized film of the present invention enables continuous deposition of a crest portion having a thick deposited film periodically on a main electrode portion, so that withstand voltage characteristics are good and safety is high. ,
It is possible to provide a vapor deposition film of a small metallized capacitor.

[Brief description of the drawings]

FIG. 1A is a schematic plan view of a single-sided vapor deposition film used in Embodiment 1 of the present invention. FIG. 1B is a schematic cross-sectional view of the single-sided vapor deposition film.

FIG. 2 is an exploded perspective view of the capacitor element used in the first embodiment.

FIG. 3 is a sectional view of the metallized film capacitor according to the first embodiment.

FIG. 4 is an exploded perspective view of the capacitor element used in the second embodiment.

FIG. 5 is an exploded perspective view of the capacitor element used in Embodiment 3;

FIG. 6 is a schematic process chart showing an embodiment of a method for producing a metallized film according to the present invention.

FIG. 7 is an enlarged perspective view of the transmission roller of the embodiment.

FIG. 8 is a comparison characteristic diagram showing a breakdown voltage.

FIG. 9 is an exploded perspective view of a capacitor element used in a conventional example.

FIG. 10 is a schematic process diagram showing a conventional method for producing a metallized film.

[Explanation of symbols]

 1a, 1b, 1c Evaporated film 7 Metallicon contact part 8 Main electrode part 9 Wave height part 14 Furnace of evaporation source 16 Transmission roller 17 Small hole 18 Oil tank

Claims (6)

[Claims] 1. A metallized film obtained by winding or laminating a vapor-deposited film in which a film thickness of a vapor-deposited film of a main electrode portion of the vapor-deposited film is rolled or a crest portion is provided periodically in a longitudinal direction. Film capacitors. 2. The metallized film capacitor according to claim 1, wherein a double-sided vapor-deposited film is disposed on both sides of the vapor-deposited film such that thick peak portions of the vapor-deposited film do not overlap each other. 3. The metallized film according to claim 1, wherein a metal of zinc or zinc-aluminum is used as a metal to be vapor-deposited on the vapor-deposited film, and a vapor-deposited film having a heavy-etched part in which a vapor-deposited film resistance value of a metallikon contact part is reduced. Capacitors. 4. A crest portion is formed on a vapor deposition film having a self-security mechanism in which a main electrode portion of a vapor deposition film is divided into a plurality of capacitors by a non-vapor deposition portion and is connected by a metallicon portion or a vapor deposition film in the vicinity of the metallicon portion. 2. The metallized film capacitor according to claim 1, wherein the metallized film capacitor is provided periodically on the deposited film. 5. A metal deposition source furnace is disposed in a cylindrical transmission roller having a periodic pattern of small holes on a circumferentially curved surface in order to periodically form a crest portion having a desired deposition thickness in a deposition film. A method of manufacturing a metallized film, wherein a crest portion is deposited by periodically changing the thickness of a deposited film while rotating the cylindrical transmission roller during film deposition. 6. The method for manufacturing a metallized film according to claim 5, wherein an oil tank for applying oil vapor is provided in the cylindrical transmission roller.