JPH10208974A - Metallized film for series capacitor and series capacitor using the same - Google Patents

Abstract

(57) [Problem] To provide a metal-deposited film and a capacitor stably exhibiting good security function in a series capacitor using the metal-deposited film. In one embodiment, a dielectric film has at least both margins or a center margin, and a metal deposited film has a size of 1 ×.
It is composed of a mosaic-like aggregate divided into small areas by thin lines having a surface resistance of 10 ³ Ωcm or more, and the small-area metal-deposited film portions divided into the thin lines are electrically connected to each other. A metal-deposited film for a series capacitor, characterized in that the thin wire portion has a conductive bottleneck portion for conduction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metallized film for a film capacitor, and more particularly to a metallized film for a series capacitor and a series capacitor using the same.

[0002]

2. Description of the Related Art FIG.
The metal deposited film is fractionated by the insulator portion as described above, and the insulator is used to electrically couple the separated vapor deposited film portion to the metal deposited film portion for electrically coupling the outside. A metallized film for a capacitor with a security mechanism margin provided with an insulator part having a fuse part (hereinafter referred to as a security mechanism margin) is practically used.

[0003] On the other hand, in a capacitor to which a high voltage is applied, a metal-deposited film having a center margin and a metal-deposited film having both margins are wound or laminated to prevent the generation of corona, and the voltage applied to the metal-deposited film is series (series). ) Is generally used. Consideration has been given to adding a security mechanism to this series capacitor.
No. 8171 proposes a metal-deposited film having a security mechanism margin by a combination of FIG. 7 and FIG.

However, in a capacitor using a metal-deposited film having a normal security mechanism margin, the fuse portion is gradually blown, and the capacitor loses its capacitance without smoking or firing. In the case of a series capacitor using a metal-deposited film having a pattern as shown in FIG. 8, when a dielectric breakdown occurs at a defective portion of the metal-deposited film, a phenomenon in which the dielectric breakdown proceeds at a stroke before the fuse is cut off may be observed. It has not yet shown security functionality.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a metallized film for a series capacitor having a safety mechanism margin which operates well, and a series capacitor using the same.

[0006]

The metal-deposited film for a series capacitor according to the present invention is a metal-deposited film having at least both margins or a center margin on a dielectric film and a metal-deposited film having a surface resistance of 1 × 10 ³ Ωcm or more. It is composed of a mosaic-like aggregate divided into small areas by thin line portions having a conductive property for electrically conducting the small-area metal-deposited film portions divided into the thin line portions. A metal-deposited film for a series capacitor, comprising a bottleneck portion in the thin wire portion.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The dielectric film referred to in the present invention means a polymer film useful as a dielectric film for capacitors, such as paper, polyester films such as polyethylene terephthalate and polyethylene naphthalate, and polyolefin films such as polypropylene. Among them, an organic polymer film having a dielectric breakdown voltage of 85% or more and 85% or more at 85 ° C. and 105 ° C. of 25 ° C., respectively, is more preferable. It is most preferable because it is high and has a small dielectric loss tangent. A metal deposition film is A
A conductive vapor-deposited film (thin film formed by vapor deposition, sputtering, or the like) useful as a capacitor electrode of a metal such as l, Zn, Cu, Fe, Ni, Cr, or an alloy thereof.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 1 and 2 which are schematic views of a metallized film for a series capacitor according to an embodiment of the present invention.

In FIG. 1, a metal deposited film 1 is provided with a center margin 2 made of an insulator for dividing the metal deposited film into two parts. The center margin 2 can be formed by preventing deposition of a metal at the time of vapor deposition, or by vapor-depositing a metal oxide as an insulator.

The metal-deposited film 3 serving as an electrode of the capacitor is a small-area mosaic-like aggregate divided by a security mechanism margin 5 having a bottleneck portion 4. Bottleneck 6
Is formed by a security mechanism margin 7 and electrically communicates the metal deposition film portion 8 for electrically coupling with the terminals of the capacitor and the fractionated metal deposition film 3.

In FIG. 2, both margins 10 made of an insulator are provided on both sides of the metal-deposited film 1 in order to maintain electrical insulation from the counter electrode of the capacitor. Both margins 10 can be formed in the same manner as the center margin 2 in FIG. The metal vapor deposition film 3 serving as an electrode of the capacitor also has a small-area mosaic-like aggregate divided by a security mechanism margin 5 having a bottleneck 4 as in FIG.

FIGS. 3A and 3B are enlarged views of the bottlenecks 4 and 6 of FIGS. 1 and 2. The features of the metallized film of the present invention are as shown in FIG. At least one of the security mechanism margins 5 and 7 has a protrusion 9, and at least one side of the bottlenecks 4 and 6 is depressed by the protrusion of the protrusion 9.

[0013] The shape of the projections 9 can form all bottlenecks into a stable and constant shape, and the security function works.
Particularly, a triangle is preferable. Further, two or more protrusions 9 may be provided as shown in FIG.

Although the method of forming the security mechanism margin of the present invention is not particularly limited, Japanese Unexamined Patent Publication (Kokai) No. 63-114957,
JP-A-6-136513 or JP-A-4-22
Transfer oil to the shape of the security mechanism margin before vapor deposition by the method described in FIG.
As described in Japanese Patent Publication No.
The method of forming the security mechanism margin is preferable because the shapes of a large number of margin portions can be made the same.

When the security mechanism margin is formed by such a method, the end of the security mechanism margin shape may be blurred and the tip of the projection 9 may be slightly rounded as shown in FIG. Does not exclude these forms.

The center margin 2 and the bottleneck portion 4 in FIG.
6. The width of the security mechanism margins 5 and 7 (a, b, c, d,
e), and the area of the fractionated small-area metal-deposited film section 3, the widths (f, b, c) of both margins 10, the bottleneck section 4, and the security mechanism margin 5 in FIG. The area of the metal-deposited film portion 3 is preferably determined by the capacitor's specifications such as the rated voltage of the capacitor, the capacitance, the type of dielectric, the thickness, the type of the metal-deposited film, and the resistance of the metal-deposited film. If the area of the small-area metal-deposited film section 3 is too small, the area of the security mechanism margin becomes large, and even if a dielectric film having the same surface area is used, the capacitance becomes small. If the area is too large, self-healing (self-healing) occurs. In this case, the bottleneck 4 is easily cut off and the decrease in capacitance is increased. Therefore, the thickness is preferably 25 mm ² to 900 mm ² , more preferably 40 mm ² to 625 mm ² , and even more preferably 100 m ² .
m ² to 225 mm ² is preferred. Next, when the ratio of the width (d) of the bottleneck portion 6 to the width (c) of the bottleneck portion 4 is less than 1.5: 1, the dielectric loss tangent becomes large, and if it exceeds 5: 1, the security function becomes difficult to work. d / c is preferably from 1.5 to 5, and more preferably from 2 to 3.

The pattern of the metal vapor deposition film of the present invention is not particularly limited, and various patterns for fractionating the vapor deposition film can be adopted.

Winding or laminating the metallized film of the present invention, for example, either FIG. 1 and FIG. 2 or FIG. 1 and FIG. 2 and a metallized film without a security mechanism margin, to form a capacitor by a usual method. This makes it possible to make a series capacitor with extremely high security. Especially,
A series capacitor obtained by winding or laminating the metal-deposited films of the present invention, for example, FIGS. 1 and 2 is a capacitor exhibiting particularly excellent security functionality.

It should be noted that the present invention does not exclude a capacitor in which a security mechanism margin pattern of a metal-deposited film is provided on both sides of one dielectric and is wound and laminated with a dielectric film on which no metal is deposited.

[0020]

【Evaluation method】

(1) Security Functionality Evaluation Method A test was performed based on JIS-C4908-1985, 8.15.2. Note capacitance of discharge capacitor C ₀ is 2 times the volume of the test capacitors. The environmental conditions for the test were 85 ° C.

[0021]

【Example】

Example 1, Example 2, Example 3, Example 4, Comparative Example 1 Ordinary polypropylene film having a thickness of 5 μm (pentad fraction: 96.2%, dielectric breakdown voltage: [25 ° C.] AC12)
00V, DC1810V, [85 ° C] AC1090V,
DC1540V, [105 ° C] AC970V, DC14
10V) and a highly stereoregular polypropylene film (pendat fraction 99.4%, dielectric breakdown voltage [25 ° C]
AC1280V, DC1890V, [85 ° C] AC11
60V, DC1740V, [105 ° C] AC1090
V, 1590 V DC), a Zn—Al alloy deposited film (Al
(Content: 4.0 wt%) to prepare a metal-deposited film having a width of 630 mm. In FIG. 1, the width a of the center margin 2 is 3.0 mm, the area of the fractionated metal deposition film 3 is 156 mm ² , and the width b of the security mechanism margin 5 is 0.4.
mm, the width e of the security mechanism margin 7 is 0.5 mm, the width c of the bottleneck part 4 is 0.6 mm, and the width d of the bottleneck part 6 is 1.2 mm. The ends of the security mechanism margins 5 and 7 that form the bottleneck are , Each having a regular triangle shape with a side length of 0.4 mm and 0.5 mm.

Metal deposition film section 8 for electrical connection with the outside
(The part where the metallikon is in close contact with the metal), and the metal deposition film resistance of the bottleneck portion 6 is 4Ω / □, and the fractionated metal deposition film portion 3
Was 8 Ω / □.

Referring to FIG. 2, the width f =
2.0 mm, the area of the fractionated metal deposition film 3 is 156 m
m ² , the width b of the security mechanism margin 5 is 0.4 mm, the width c of the bottleneck section 4 is 0.6 mm, and the end of the security mechanism margin 5 forming the bottleneck section 4 is a regular triangle having a side length of 0.4 mm. Shaped. The metal deposition film resistance of the fractionated metal deposition film part 3 is 8
Ω / □.

Next, a metal-deposited film having a security mechanism margin shown in FIG. 7 and a metal-deposited film having no security mechanism margin shown in FIGS. 8 and 9 were prepared using a normal polypropylene film. FIG. 7 shows the width f of both margins 10.
= 2.0 mm, security mechanism margin 5 width b = 0.4 m
m, width e of security mechanism margin 7 = 0.5 mm, bottleneck 4
The width c = 0.4 mm, and the end of the security mechanism margin 7 that forms the bottleneck portion 4 is a semicircle having a diameter of 0.5 mm. The gap g of the security mechanism margin 5 was set to 51 mm. The metal deposition film resistance of the metal deposition section 3 was 8Ω / □.

Referring to FIG. 8, the center margin width a =
Normal vapor deposition having a security mechanism margin of 3.0 mm was used. The metal deposition film resistance of the metal deposition film part 3 was 8Ω / □. The resistance of the metal-deposited film of the metal-deposited film portion 8 for electrical connection with the outside was set to 4Ω / □ as in FIG.

Referring to FIG. 9, the width f of both margins 10 =
The vapor deposition was 2.0 mm, and normal vapor deposition without a security mechanism margin was performed. The metal deposition film resistance of the metal deposition film part 3 is 8Ω / □.
And

The security mechanism margin was formed by transferring oil to polypropylene in the form of each security mechanism margin before vapor deposition in a vacuum vapor deposition machine, and then depositing Al and Zn. These metal-deposited films are shown in FIGS.
2, 7 and 9 show a combination of FIGS. 1 and 2 using a polypropylene film having a high stereoregularity after slitting to a width of 60 mm (Example 1). Combination of FIG. 1 and FIG. 2 using Example (Example 2), combination of FIG. 1 and FIG. 9 (Example 3), FIG.
In the combination of FIG. 8 and Example 8 (Example 4) and in the combination of FIG. 7 and FIG. 8 (Comparative Example 1), winding, metallikon, heat treatment and lead attachment are performed, and then put in a plastic case and filled with epoxy resin. A capacitor having a capacity of 4.5 μF was prepared by the method described above. The number n was set to 3.

Table 1 shows the results of evaluating the security functionality of these series capacitors. As shown in Table 1, the capacitor using the metal-deposited film for a series capacitor of the present invention stably exhibited good security performance.

[0029]

[Table 1]

[0030]

According to the present invention, there is provided a mosaic having a small area by a thin line portion having at least both margins or a center margin on a dielectric film and having a surface resistance of 1 × 10 ³ Ωcm or more. Is divided into a set of
In addition, a metallized film for a series capacitor and a series exhibit a stable security function by providing a conductive fuse for electrically conducting the small-area metallized film portions fractionated by the thin wire portion. A capacitor is provided.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a metallized film for a series capacitor having a security mechanism margin according to the present invention.

FIG. 2 is a schematic view showing an example of a metallized film for a series capacitor having a security mechanism margin according to the present invention.

FIG. 3 is a schematic view showing an example of the shape of an end portion and a bottleneck forming a bottleneck of a security mechanism margin of the present invention.

FIG. 4 is a schematic view showing an example of the shape of an end portion and a bottleneck forming a bottleneck of a security mechanism margin of the present invention.

FIG. 5 is a schematic diagram showing an example of the shape of the end portion and the bottleneck forming the bottleneck of the security mechanism margin of the present invention.

FIG. 6 is a schematic view showing an example of a metal-deposited film having a security mechanism margin.

FIG. 7 is a schematic view showing an example of a metallized film for a series capacitor having a security mechanism margin.

FIG. 8 is a schematic view showing an example of a metal-deposited film having a normal center margin without a security mechanism margin.

FIG. 9 is a schematic view showing an example of a metal-deposited film having both normal margins without a security mechanism margin.

[Explanation of Signs] 1: Metal deposited film 2: Center margin 3: Metal deposited film part to be an electrode of capacitor 4: Bottleneck 5: Security mechanism margin 6: Bottleneck 7: Security mechanism margin 8: Electricity outside the capacitor Metal-deposited film for coupling 9: Projection of security mechanism margin 10: Both margins a: Center margin width b: Security mechanism margin width c: Bottleneck width d: Bottleneck width e: Security mechanism margin Width f: Width of both margins g: Spacing of security mechanism margin

Claims (8)

[Claims] 1. A metal film having at least both margins or a center margin on a dielectric film, and
It is composed of a mosaic-like aggregate divided into small areas by fine lines having a surface resistance of × 10 ³ Ωcm or more, and the small-area metal-deposited film portions divided into the fine lines are electrically connected to each other. A metal-deposited film for a series capacitor, characterized in that the thin wire portion has a conductive bottleneck portion for conducting electricity to the thin film portion. 2. A small-area metal-deposited film portion divided by a thin line portion has an area of 25 mm ² or more and 900 mm ² or more.
^{2. The} metal deposited film for a series capacitor according to claim 1, wherein the number is ² or less. 3. The metal-deposited film for a series capacitor according to claim 1, wherein the tip of the thin wire portion forming the bottleneck portion has an acute angle. 4. A bottleneck portion (c) for electrically connecting a small-area metal-deposited film to a small-area metal-deposited film for electrically connecting the small-area metal-deposited film to an electrode. The metal deposited film for a series capacitor according to any one of claims 1 to 3, wherein the film thickness is 1.5 times to 5 times of the above. 5. A dielectric film at 85 ° C. and 105 ° C.
95% or more and 85% respectively when the dielectric breakdown voltage at 25 ° C is 25 ° C
The metal vapor-deposited film for a series capacitor according to any one of claims 1 to 4, wherein an organic polymer film having a content of at least 10% is used. 6. The metal deposited film for a series capacitor according to claim 5, wherein the organic polymer film is a film made of polypropylene. 7. A series capacitor comprising the metal-deposited film for a series capacitor according to claim 1 used for at least one of the metal-deposited films. 8. A series capacitor obtained by winding or laminating the metallized films for a series capacitor according to claim 1. Description: