JPH08293427A - Metal-vapor deposition film - Google Patents

Abstract

PURPOSE: To provide a highly reliable metal-vapor deposition film for forming capacitors which excells in self-healing property and in corona resistance and concurrently can operate a safety mechanism accurately. CONSTITUTION: A metal-vapor deposition film for forming capacitors which has a margin for forming a safety mechanism or a margin for dividing its vapor deposition membrane into capacitors with small capacitance to form their aggregate, wherein the vapor deposition membrane of the metal-vapor deposition film is made of the alloy of Zn and Al whose Al content is not smaller than 5wt.% and is not larger than 20wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal vapor deposition film for capacitors, and more particularly to a metal vapor deposition film having a margin for forming a safety mechanism, or a margin for forming a small-capacity capacitor assembly by dividing a vapor deposition film. The present invention relates to a metal vapor deposition film having

[0002]

2. Description of the Related Art Heretofore, in order to enhance the safety of capacitors, many metal vapor deposition films having various margin undeposited portions forming a safety mechanism have been proposed. For example, JP-B-14-3419, JP-B-63-9648, JP-B-63-9653, JP-B-63-9654, JP-B-63-12627, JP-B1-30284, and JP-B-1-30285. Publication, British Patent No. 1079203
Nos., British Patent No. 876274, European Patent Publication No. 0017556, and the like.

Further, US Pat. No. 5,057,967 proposes to divide a vapor-deposited film to provide a margin for forming an aggregate of capacitors having a small capacity.

Further, Japanese Patent Application Laid-Open No. 4-225508 or Japanese Patent Application Laid-Open No. 6-310368 proposes a structure in which divided small-capacity capacitors are connected by a narrow vapor deposition film having a fuse function.

All of these are intended to prevent the destruction of the capacitor by allowing the vapor deposition film to have a fuse function with a margin and operating the fuse function when the vapor deposition film fails in self-healing.

However, if the self-recovery fails frequently, the fuses are blown one after another, the capacitance formed by the vapor deposition film divided by the margin is lost one after another, and the capacitance of the capacitor is remarkably reduced. . Therefore, in order to solve this problem, an Al vapor deposition film having an excellent self-recovery property is used as the vapor deposition film.

On the other hand, it is well known that the Al vapor-deposited film is deteriorated by corona discharge and has a drawback that the capacity of the capacitor is lowered. However, in the present situation, the safety is emphasized and the Al vapor-deposited film is mainly used. There is.

[0008]

SUMMARY OF THE INVENTION The present invention has an excellent self-healing property and an anti-corona deterioration property, and at the same time, improves the reliability of the capacitor by the effect of the fuse function portion formed by the margin. An object of the present invention is to provide a metal vapor deposition film for use.

[0009]

A metal vapor deposition film of the present invention for this purpose is for a capacitor having a margin for forming a safety mechanism or a margin for dividing a vapor deposition film to form an aggregate of small capacity capacitors. The metal vapor deposition film is characterized in that the vapor deposition film of the metal vapor deposition film is made of an alloy of Zn and Al containing 5 wt% to 20 wt% of Al.

The margin for forming the security mechanism in the present invention means that when self-recovery fails and a large current flows, the vapor deposition film of the fuse portion formed by the margin is melted or the vapor deposition film is cracked. The margin of the vapor-deposited film divided or fractionated by means of the vapor-deposited film can be divided or fractionated so that the conduction with the electrode extraction portion is lost. For example, Japanese Patent Publication Nos. -9
648, Japanese Patent Publication No. 63-9653, Japanese Patent Publication No. 63-96
54, Japanese Examined Japanese Patent Publication No. 63-127127, Japanese Examined Patent Publication 1-302
No. 84, Japanese Examined Patent Publication No. 1-30285, British Patent No. 1
No. 079203, British Patent No. 876274, European Patent Publication No. 0017556, etc. show examples of this pattern.

FIG. 1 and FIG. 3 show these typical margin patterns. However, the margin for forming the safety mechanism of the vapor deposition film with the safety mechanism of the present invention is not limited to these.

In the pattern shown in FIG. 1, a continuously extending margin 1 is formed at one end of the film in the width direction, and the vapor deposition film 2 is divided in the film longitudinal direction by a margin 3 extending in the film width direction. Has been done.
In the pattern shown in FIG. 3, the vapor deposition film 4 is divided by the margin 5, and the end vapor deposition film portion 6 and the central vapor deposition film portion are connected via the narrow vapor deposition film 7.

Further, the margin forming the aggregate of small-capacity capacitors by dividing the vapor-deposited film is a fine division of the vapor-deposited film by a margin, and as a typical example, US Pat.
No. 057967 (corresponding Japanese application: JP-A-3-57
No. 206), and its margin pattern is shown in FIG. In FIG. 4, the vapor deposition film 10 is finely divided by a margin 8 extending in the longitudinal direction of the film and a margin 9 extending in the width direction, and two metal vapor deposition films are laminated with the margin positions shifted. Of course, the margin of the present invention is not limited to this.

Further, a margin for dividing the vapor-deposited film to form an aggregate of capacitors having a small capacity, and a margin for connecting the margins with a fuse portion is also an important margin in the present invention. -225508
And the margins of JP-A-6-310368 and the like. FIG. 5 shows a typical margin pattern. In FIG. 5, margins 11 and 1 that are inclined and extend intermittently
The vapor deposition film 13 is finely divided by 2, and the respective portions of the divided vapor deposition film 13 are connected by the fuse portion 14. However, the margin of the present invention is not limited to this example.

Capacitors made from a vapor deposition film having these margins exhibit a good security function, but in many cases metal vapor deposition films with poor self-healing properties, such as Zn vapor deposition films, fail to self-recover. As a result, the security function of the fuse portion is activated, resulting in a large decrease in capacity. On the other hand, with Al having excellent self-recovery property, the capacity is significantly reduced due to deterioration of corona discharge.

In the present invention, the self-recovery is achieved by forming an alloy of Zn and Al into a vapor-deposited film and setting the content of Al to 5% by weight or more and 20% by weight or less, preferably 8% by weight or more and 15% by weight or less. It is possible to make full use of the safety function of the formed margin by improving the property and suppressing the capacity decrease due to the deterioration of corona discharge. Further, the weight% of Al and Zn in the interface between the polymer film and the vapor deposition film, the intermediate portion between the interface and the surface of the vapor deposition film and the surface of the vapor deposition film are a ₁ , b ₁ , a ₂ , b respectively. ₂ , a
₃ , b ₃ (however, a ₁ , a ₂ , a ₃ are weight% of Al at each position, b ₁ , b ₂ , b ₃ are weight% of Zn at each position, and a _i + b _i = 100% , I = 1, 2, 3), A is set so that a ₂ <a ₃ <a ₁ as shown in FIG.
Due to the continuous change of the content of l, the self-recovering property is further excellent, the self-recovering function is not deteriorated even under high humidity, and the capacity change due to corona deterioration or humidity deterioration is small, and thus formed. It is possible to provide a metal deposition film that further utilizes the security function of the margin.

During the deposition of Zn and Al alloy, 1% by weight
The following Cu, Si, Mg, Mn, Cr, Pb, Sn, F
Although metals other than Al and Zn such as e and Cd may be contained, some of these metals improve moisture resistance such as Si, but the content is preferably as small as possible in order to promote corrosion. There are also preferred metals, preferably less of these metals, more preferably less than 0.1% total weight.

Further, the moisture resistance can be further improved by providing an organic material layer on the vapor-deposited film of Al and Zn.

In order to observe the content and composition distribution of Al and Zn in the deposited film of Al and Zn, first, certain amounts of Al and Z
After dissolving the vapor deposition layer of n using hydrochloric acid, the content of each of Al and Zn is quantified by plasma emission spectroscopy (ICP). Further, the polymer vapor deposition film is applied to an Auger electron spectroscope, and the atomic composition of Al and Zn is measured while sputter etching the vapor deposition film from the surface of the vapor deposition film of Al and Zn. When the atomic composition data thus obtained is normalized by the Al and Zn contents obtained by ICP, the Al and Zn composition distribution chart of FIG. 2 can be obtained, where a ₁ , b ₁ ,
_{a 2, b 2, a 3} , b 3, and weight percent of the total Al can be determined.

The interface between the polymer film and the vapor-deposited film is at a point of 1/2 of the value at which the Auger peak of C (carbon atom) derived from the polymer film is saturated. Further, the interface and the intermediate portion of the surface of the vapor-deposited film are 1/2 between the interface and the surface of the vapor-deposited film.
Point.

[Measurement of Physical Properties] (1) Quantification of Al and Zn A sample (9 cm ² ) was dissolved in dilute nitric acid and then dissolved in 20 ml, and this fixed solution was quantified for Al and Zn by ICP emission spectroscopy. . As the ICP emission spectroscopic analyzer, SPS1200VR type manufactured by Seiko Instruments Inc. was used.

(2) Al and Zn composition distribution A JAMP-10S type Auger electron spectroscopy analyzer manufactured by JEOL was used to quantitatively analyze Al and Zn while etching Ar ions from the surface of the deposited film. Ar ion etching conditions Acceleration voltage: 3 kV Sample current: 1 × 10 ⁻⁶ A Etching rate: 190 Å / min in terms of SiO ₂ Measurement conditions Acceleration voltage: 3 kV Slit No. : 5 sample current: 8 × 10 ^-8 A sample tilt angle: 72 degrees beam diameter: 10 μm

(3) Capacitance (C) The capacitance was measured by a Schering bridge at 60 Hz and 400V. Equipment is manufactured by Soken Denki Co., Ltd., AUTOMATIC S
CHERRING BRIGE DAC-PSC-20W
The mold was used.

(4) Safety Performance Evaluation According to JIS-C4908 (1958), a safety tester CT-507 (T) (manufactured by AST) was used, and AC voltage:
288 V, DC voltage: 50 V / step, step interval: 6 minutes, the voltage was boosted, and when the current stopped flowing or the DC voltage at the time of breakdown was read, the quality of the operation of the security function was determined. The test temperature was 85 ° C.

(5) Continuous durability test: AC300V was applied in an atmosphere of 60 ° C. and 90% RH, and a capacity change ΔC (= capacity after test−capacity before test) / (capacity before test) after 2000 hours. Capacity) x 100)
Was measured. The capacitor was disassembled and the mode of capacity reduction was investigated.

[0026]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the examples. Examples 1 to 5 and Comparative Examples 1 to 4 Zn-Al was added to a polypropylene film having a thickness of 4.5 μm.
The alloy was vapor-deposited and slit to prepare the metal vapor-deposited film for the capacitor of FIG. The width of the evaporation film is 50
mm, the width of the free mazine (1) is 2 mm, the width of the security mechanism forming margin (3) is 0.4 mm, the interval of the security mechanism forming margin (3) is 17 mm (the length of the vapor deposition film (2) is 16 mm). It is 0.6 mm). The resistance of the vapor deposition film is 5Ω / □ at the adhesion part with the metallikon and 8Ω / □ at the main capacitance part.
And Table 1 shows the weight ratio of Zn and Al.

As a comparative example, a Zn vapor deposition film, an Al vapor deposition film,
A vapor deposition film having a vapor deposition film containing a small amount of Al and a vapor deposition film containing a large amount of Al was prepared.

These vapor deposition films were wound, heat treated, metallikon, electrode welded and impregnated with wax to prepare a capacitor element. Table 1 shows the evaluation results of the capacitor element thus manufactured.

The film wound together with these vapor-deposited films is a normal vapor-deposited film having only a free margin obtained by vapor-depositing an Al-Zn alloy having an Al content of 8% by weight on a polypropylene film having a thickness of 4.5 μm. Yes, the vapor deposition film resistance is 5Ω / □ for the metallikon adhesion part and 8Ω for the main capacitance part.
It is a heavy-edge type vapor deposition film of / □.

[0030]

[Table 1]

As shown in Table 1, when the Al content in the Al-Zn alloy is 5 wt% or more and 20 wt% or less, ΔC
Is small and has excellent clearing property,
The safety mechanism worked effectively at high voltage and showed excellent characteristics. Particularly, an Al content of 8% by weight or more and 15% by weight or less is excellent.

Example 6, Comparative Examples 5 and 6 In Example 6, a polyester film having a thickness of 4.0 μm was used, and a vapor deposition film having the same security mechanism forming margin as in Example 1 and the same width was formed. . The deposited film is Al-
Zn alloy with Al content of 8.1% by weight, a ₁ = 6
It was 7.2% by weight, a ₂ = 3.2% by weight, and a ₃ = 13.6% by weight.

As Comparative Example 5, Al was first vapor-deposited on a 4.0 μm polyester film, and then Zn was vapor-deposited on the Al vapor-deposited film, and the weight ratio of Al to Zn was 9.6 wt%: 90. A vapor deposition film with a margin for forming a safety mechanism, which was the same as that in Example 1, was prepared at 4% by weight.

Further, as Comparative Example 6, Zn film with Cu nuclei was vapor-deposited on a polyester film having the same thickness, and then Al was deposited on the Zn vapor-deposited film.
The vapor deposition film with the same margin for forming the safety mechanism as that in Example 1 was prepared, in which the weight ratio of was set to 8.6% by weight: 91.4% by weight.

These were overlaid with a normal heavy-edge vapor deposition film of the same size (without a margin for forming a safety mechanism), which was obtained by vapor-depositing a Zn-Al vapor deposition film containing 10.2% by weight of Al on a polyester film of 4.0 μm. , Winding,
A capacitor element was prepared in the same manner as in Example 1 and its characteristics were evaluated. Table 2 shows the results.

[0036]

[Table 2]

Thus, the capacitor prepared from the metal vapor deposition film according to the present invention showed good results without breakage.

[0038]

As described above, when the metal deposition film of the present invention is used, the safety mechanism forming margin and A
By combining a vapor-deposited film made of an alloy of Zn and Al containing 5% by weight or more and 20% by weight or less, destruction due to deterioration of self-recoverability even under high humidity, and capacity due to excessive function of safety mechanism Good characteristics were obtained without causing deterioration.

[Brief description of drawings]

FIG. 1 is a schematic vapor deposition pattern diagram and a sectional view of a metal vapor deposition film according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an example of a composition amount distribution of Al and Zn of a vapor deposition film of Al and Zn of a vapor deposition film of the present invention.

FIG. 3 is a schematic plan view showing a vapor deposition pattern of a film having a margin forming a security mechanism used as the metal vapor deposition film of the present invention.

FIG. 4 is a schematic plan view showing a vapor deposition pattern of a metal vapor deposition film having a margin for dividing a vapor deposition film into a group of capacitors having a small capacity.

FIG. 5 is a schematic plan view showing a vapor deposition pattern of another metal vapor deposition film having a margin that divides the vapor deposition film to form an aggregate of capacitors having a small capacity.

[Explanation of symbols]

1 Undeposited part extending in the longitudinal direction (free margin) 2, 4, 10, 13 Vapor-deposited film part 3 Undeposited part extending in the width direction (security mechanism forming margin) 5 Dividing margin 6 Edge-deposited part 7 Fuse part 8 Margins extending in the longitudinal direction 9 Margins extending in the width direction 11, 12 Margins extending obliquely intermittently 14 Fuse portion

Claims (3)

[Claims] 1. A metal vapor deposition film for a capacitor having a margin for forming a security mechanism or a margin for dividing a vapor deposition film to form an aggregate of capacitors having a small capacity, wherein the vapor deposition film of the metal vapor deposition film contains Al 5 A metal vapor deposition film comprising an alloy of Zn and Al in an amount of 20% by weight or more and 20% by weight or less. 2. The metal vapor deposition film according to claim 1, wherein the vapor deposition film is made of an alloy of Zn and Al containing 8 wt% or more and 15 wt% or less of Al. 3. A at the interface between the film and the vapor-deposited film, an intermediate portion between the interface and the surface of the vapor-deposited film, and A at the surface of the vapor-deposited film.
The weight percentages of 1 and Zn are respectively a ₁ , b ₁ , a ₂ , b ₂ ,
a ₃ , b ₃ (however, a ₁ , a ₂ , a ₃ are Al at each position)
% By weight, b ₁ , b ₂ , b ₃ are weight% of Zn at each position
In _{a i + b i = 100%} , when a i = a _{1,2,3), a 2 <a 3} < Al content so that a ₁ is continuously changed, according to claim 1 Or a metallized film of 2.