JP2011014563A - Metallized film capacitor and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallized film capacitor achieving stable capacitor characteristics, even when connected with a large-current terminal, by improving a bonding strength between a metalicon electrode and an end face of a capacitive element, and to provide a method for manufacturing the metallized film capacitor.SOLUTION: A metallized film capacitor includes: a capacitive element comprising a pair of metallized films including a metal deposition electrode, arranged oppositely so that each insulation margin of the metallized films is located at an opposite side in the width direction to each other, and laminated or wound, wherein the metal deposition electrode is formed on a surface of a dielectric film while the insulation margin is left; and metalicon electrodes formed on both end faces of the capacitive element. The metalicon electrodes comprise an alloy at least containing tin, zinc and bismuth, wherein the alloy has a composition consisting of 6.0-10.0 wt.% zinc and 1.0-5.0 wt.% bismuth, with the balance being tin.

Description

  The present invention relates to a metallized film capacitor having a capacitor element formed by winding or laminating a metallized film in which a vapor deposition electrode is formed on a plastic film, and a method for manufacturing the same.

  Many metallized film capacitors are used for electronic and electrical devices, such as polypropylene (PP) film and polyethylene terephthalate (PET) film, which are wound or laminated with metallized film deposited with aluminum or zinc. (For example, Patent Document 1). Since these metallized film capacitors have self-healing performance even if the dielectric contains an insulation defect, they have a feature that can be miniaturized by designing a high potential gradient.

  On the other hand, capacitors for industrial equipment, in particular, capacitors used in filter circuits for automobiles or the like, have a large energization current, and therefore need to have improved current resistance. This metallized film capacitor forms an extraction electrode by contact between an ultrathin vapor deposition electrode and a metallicon electrode, and the current resistance is inferior to a non-self-recovering capacitor using an electrode foil. As an improvement, a method is employed in which the thickness of the portion of the vapor deposition electrode that contacts the metallicon electrode is made thicker than the capacity forming portion.

  Further, zinc, zinc / tin alloy, or the like is adopted as a metallized electrode of the metallized film capacitor, and a terminal or the like is solder-connected to the metallized electrode.

JP 2007-080908 A

  As described above, when zinc or zinc-tin alloy is used as the metallicon electrode, the melting point of these metallicon electrodes is high, so the bonding strength between the metallicon electrode and the end face of the metallized film capacitor due to the heat when connecting a large current terminal such as a bus bar. May decrease. As a result, the contact of the metallicon electrode connecting portion is deteriorated, and a discharge is generated between the metallicon electrode and the metallized film, and the deposited metal in the vicinity of the capacitor end face is scattered, resulting in a problem that the capacitor characteristics are deteriorated.

  The present invention has been made in view of the above technical problem, and an object of the present invention is to provide a metallized film capacitor capable of obtaining stable capacitor characteristics even when connected to a large current terminal, and a method for manufacturing the same.

  In the metallized film capacitor of the present invention, a pair of metallized films in which a metal vapor deposition electrode is formed leaving an insulation margin on the surface of the dielectric film, the insulation margins of the metallized film are positioned on opposite sides in the width direction. The capacitor element is disposed so as to face each other, and is laminated or wound, and the metallicon electrodes formed on both end faces of the capacitor element, and the metallicon electrode is made of an alloy containing at least tin, zinc, and bismuth. (First invention).

  The method of manufacturing a metallized film capacitor according to the present invention includes a pair of metallized films in which a metal vapor-deposited electrode is formed on the surface of a dielectric film while leaving an insulation margin. An element forming step of forming a capacitor element by being arranged facing each other so as to be positioned at each other, and forming a metallicon electrode made of an alloy containing at least tin, zinc, and bismuth on both end faces of the capacitor element And a forming step (sixth invention).

  According to this configuration, the melting point of the metallicon electrode is low, the bonding strength between the metallicon electrode and the end face of the capacitor element is improved, and even when connected to a large current terminal, it is suppressed that the metallicon electrode is peeled off or disconnected. Stable capacitor characteristics can be obtained.

  In the metallized film capacitor of the present invention, it is preferable that the alloy has a composition in which zinc is 6.0 to 10.0 wt%, bismuth is 1.0 to 5.0 wt%, and the balance is tin (second). Invention).

  In the metallized film capacitor of the present invention, it is preferable that the alloy further contains antimony (third invention).

  At this time, it is more preferable that the alloy has a composition in which zinc is 6.0 to 10.0 wt%, bismuth is 1.0 to 5.0 wt%, antimony is 1.0% or less, and the balance is tin ( Fourth invention).

In the metallized film capacitor of the present invention, the metallicon electrode includes a first metallicon layer made of zinc sprayed on both end faces of the capacitor element, and a first alloy made of the alloy sprayed on the first metallicon layer. It is preferable to have two metallicon layers (fifth invention).
In the method for producing a metallized film capacitor of the present invention, the electrode forming step includes a first step of spraying zinc on both end faces of the capacitor element to form a first metallicon layer, and a step on the first metallicon layer. It is preferable to have a second step of thermally spraying the alloy to form a second metallicon layer (seventh invention).

  According to the present invention, since the bonding strength between the metallicon electrode and the capacitor element end face is improved, the metallicon electrode is prevented from being peeled off or disconnected even when connected to a large current terminal, and stable capacitor characteristics are obtained. be able to.

It is an external appearance perspective view of the metallized film capacitor regarding the embodiment of the present invention. It is an external appearance perspective view of the capacitor | condenser element shown in FIG. It is a fragmentary sectional view of the metallized film shown in FIG. It is a block diagram which shows the manufacturing method of the capacitor | condenser element shown in FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the metallized film capacitor 1 of this embodiment includes a capacitor element 6, a plastic case 7 that houses the capacitor element 6, and an epoxy resin 8 that seals the capacitor element 6 in the plastic case 7. It consists of and.

As shown in FIGS. 2 and 3, the capacitor element 6 includes two wound metallized films 3 (a pair), and a metallized electrode 5 formed on each end surface of the wound metallized film 3. And a lead wire 9 connected to each metallicon electrode 5.
The metallized film 3 includes a long PP film 11 having a thickness of 4 μm and an aluminum vapor deposition electrode 12 formed on the PP film 11 so that an insulation margin 13 remains at one end in the longitudinal direction of the PP film 11. Have.

  In the capacitor element 6, the two metallized films 3 as described above are provided on one side of the metallized film 3 on which the aluminum vapor-deposited electrode 12 is formed, and on the other side of the metallized film 3. In a state where the surface on which the side 12 is formed and the surface on the opposite side are in contact with each other, and the insulating margins 13 of the two metallized films are overlapped so as to be located on the opposite sides in the width direction. It is wound along the longitudinal direction.

After the metallicon electrode 5 is sprayed with zinc on each end face of the pair of metallized films 3 wound,
(A) an alloy having a composition of 6.0 to 10.0 wt% zinc, 1.0 to 5.0 wt% bismuth, and the balance tin, or
(B) It is formed by spraying an alloy having a composition of 6.0 to 10.0 wt% zinc, 1.0 to 5.0 wt% bismuth, 1.0 wt% or less antimony, and the balance being tin. .

  One end of the lead wire 9 is connected to the vicinity of the center of each metallicon electrode 5 and extends along the major axis direction of the wound capacitor element.

Next, a manufacturing method of the metallized film capacitor 1 will be described with reference to FIG.
The metallized film 3 is produced on the long PP film 11 having a thickness of 4 μm by the above-described method, and the two metallized films are superposed on each other so that the insulation margins 13 of the two metallized films are located on opposite sides in the width direction. Then, it is wound along the longitudinal direction (element forming step).

Zinc is sprayed onto both end faces of the wound capacitor element (first step in the electrode forming step).
Further, on the surface of the sprayed zinc, (a) an alloy having a composition in which zinc is 6.0 to 10.0 wt%, bismuth is 1.0 to 5.0 wt%, and the balance is tin, or (b) zinc An alloy having a composition of 6.0 to 10.0 wt%, bismuth 1.0 to 5.0 wt%, antimony 1.0 wt% or less, and the balance being tin is sprayed (second step in the electrode forming step).

  In addition, as described above, the metallicon electrode 5 is not formed on the surface of the sprayed zinc, but is described directly on the both end faces of the wound capacitor element as described in the above (a) or (b). The metallicon electrode 5 may be formed by spraying an alloy.

  A capacitor element 6 is formed by connecting a lead wire 9 to each metallicon electrode 5 (lead wire connection).

  After the capacitor element 6 obtained by the above steps is housed in a plastic case 7, the case is filled and cured with an epoxy resin 8 to complete the metallized film capacitor 1.

  Next, an embodiment according to the present invention will be described in comparison with a conventional example. In Examples and Conventional Example 1 described below, only the composition of the metallicon electrode (electrode forming process) is different, and the other processes are all the same. The number of samples was 10 each, and a metallized film capacitor with a rating of 10V-10 μF was produced.

[Examples 1 to 9] Composition comparison of zinc 4.0 to 12.0 wt%, bismuth 0.5 to 7.0 wt%, and the remainder of tin After using the capacitor element of the above specifications and spraying zinc on both end faces, As shown in Table 1, a metallicon electrode was formed from an alloy having a composition of 4.0 to 12.0 wt% zinc, 0.5 to 7.0 wt% bismuth, and the balance tin.

(Conventional example 1)
A capacitor element having the same specifications as the above example was used, and after spraying zinc on both end faces thereof, an alloy composed of 50.0 wt% tin and 50.0 wt% zinc was sprayed to form a metallicon electrode.

  For each of the ten metallized film capacitors of Examples 1 to 9 and the conventional example, a temperature cycle test of −40 ° C. to 120 ° C. was performed 2000 cycles, and the number of occurrences of tan δ and disconnection was measured for each. The results are shown in Table 1.

As is apparent from Table 1, in Examples 1 to 9 using an alloy having a composition of zinc 4.0 to 12.0 wt%, bismuth 0.5 to 7.0 wt%, and the balance of tin, after 2000 cycles of the temperature cycle test The number of occurrences of disconnection is reduced as compared with the conventional example, and the change in tan δ is also small. Among them, in Examples 2, 4 to 6, and 8 using alloys having a composition of 6.0 to 10.0 wt% zinc, 1.0 to 5.0 wt% bismuth, and the balance tin, occurrence of disconnection In addition, the change in tan δ is smaller, which is preferable.
In contrast, in the conventional example, disconnection failure occurred in 6 out of 10 metallized film capacitors, and the increase in tan δ was also large for the remaining 4 metallized film capacitors.

[Examples 10 to 22] Composition comparison of zinc 4.0 to 12.0 wt%, bismuth 0.5 to 7.0 wt%, antimony 1.2 wt% or less, tin balance Next, capacitors having the same specifications as the above examples After spraying zinc on both end faces of the device, as shown in Table 2, 4.0 to 12.0 wt% zinc, 0.5 to 7.0 wt% bismuth, and 1.2 wt% antimony Hereinafter, a metallicon electrode was formed of an alloy having a composition in which the balance was tin.

  Each of the ten metallized film capacitors of Examples 10 to 22 was subjected to a temperature cycle test of −40 ° C. to 120 ° C. for 2000 cycles, and the number of occurrences of tan δ and disconnection was measured for each. The results are shown in Table 2.

  As is apparent from Table 2, an alloy using a composition in which zinc is 4.0 to 12.0 wt%, bismuth is 0.5 to 7.0 wt%, antimony is 1.2 wt% or less, and the balance is tin is used. In Examples 10 to 22, the number of disconnections after 2000 cycles of the temperature cycle test is reduced as compared with the conventional example, and the change in tan δ is also small. Among them, Examples 11, 13 to 13 using alloys having a composition in which zinc is 6.0 to 10.0 wt%, bismuth is 1.0 to 5.0 wt%, antimony is 1.0 wt% or less, and the balance is tin. Nos. 17, 19, and 21 are preferable because there is no occurrence of disconnection and the change in tan δ is smaller.

  In the above embodiment, the alloy metallicon electrode 5 in which the weight ratio of tin, zinc, bismuth, and antimony is changed is formed on the surface of the sprayed zinc, but both ends of the capacitor element are formed without using the sprayed zinc. Even when the above metallicon alloy was sprayed directly on the surface, good results were obtained as in the above examples.

DESCRIPTION OF SYMBOLS 1 Metallized film capacitor 3 Metallized film 5 Metallicon electrode 6 Capacitor element 7 Plastic case 8 Epoxy resin 9 Lead wire 11 PP film 12 Aluminum vapor deposition electrode 13 Insulation margin

Claims (7)

A pair of metallized films, on which a metal vapor deposition electrode is formed leaving an insulation margin on the surface of the dielectric film, are arranged to face each other so that the insulation margins of the metallized film are located on opposite sides in the width direction. A rotated capacitor element;
Metallicon electrodes formed on both end faces of the capacitor element,
The metallized electrode capacitor is made of an alloy containing at least tin, zinc, and bismuth.   2. The metallized film capacitor according to claim 1, wherein the alloy is composed of 6.0 to 10.0 wt% zinc, 1.0 to 5.0 wt% bismuth, and the balance tin. 3.   The metallized film capacitor of claim 1, wherein the alloy further includes antimony.   4. The metallized film according to claim 3, wherein the alloy is composed of 6.0 to 10.0% by weight of zinc, 1.0 to 5.0% by weight of bismuth, 1.0% or less of antimony, and the balance being tin. Capacitor. The metallicon electrode is
A first metallicon layer made of zinc sprayed on both end faces of the capacitor element;
5. The metallized film capacitor according to claim 1, further comprising a second metallicon layer made of the alloy sprayed on the first metallicon layer. A pair of metallized films, on which a metal vapor deposition electrode is formed leaving an insulation margin on the surface of the dielectric film, are arranged facing each other so that the insulation margins of the metallized film are located on opposite sides in the width direction. An element forming step of turning to form a capacitor element;
An electrode forming step of forming a metallicon electrode made of an alloy containing at least tin, zinc, and bismuth on both end faces of the capacitor element. The electrode forming step includes
A first step of thermally spraying zinc on both end faces of the capacitor element to form a first metallicon layer;
The metallized film capacitor manufacturing method according to claim 6, further comprising: a second step of spraying the alloy on the first metallicon layer to form a second metallicon layer.

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