JP5054610B2 - Method for manufacturing wound electrolytic capacitor - Google Patents

Description

  The present invention relates to a method for manufacturing a wound electrolytic capacitor in which an anode foil and a cathode foil are wound via a separator.

Conventionally, a wound electrolytic capacitor in which an anode foil and a cathode foil are wound via a separator is well known as an electrolytic capacitor.
In the manufacturing process of such a wound electrolytic capacitor, an aluminum foil or the like is subjected to etching treatment or anodizing treatment, and then cut into a predetermined length to produce both electrode foils.
And after connecting a lead wire to these both electrode foils via the tab, respectively, the separator is overlapped between both electrode foils and wound around the core.

In recent years, electrolytic capacitors have been required to be miniaturized, and in order to meet this demand, the use of thinner separators has been studied. However, since the withstand voltage of the separator decreases as the thickness is reduced, the portion that contacts the tab where current is concentrated tends to break, resulting in a short mode between the tabs or between the electrode foil and the tab. It becomes easy to do.
Therefore, as in Patent Document 1, a wound electrolytic capacitor in which a protective paper is disposed between the tab and the separator has been proposed in order to prevent breakage of a portion in contact with the tab of the separator. In the manufacturing process of the wound electrolytic capacitor, a protective paper is disposed on a tab fixed on the electrode foil, and then wound with a separator interposed between the two electrode foils.

JP 2000-124072 A

In the wound electrolytic capacitor, a short mode is likely to occur at the winding start portion and the winding end portion. The reason is considered as follows.
In the manufacturing process of the wound electrolytic capacitor, since the electrode foil is cut after being subjected to etching treatment or anodizing treatment, the electrode foil is cut at both ends (winding start portion and winding end portion) of the electrode foil. Burr is generated, and the burr tends to cause a short mode at the end portions of both electrode foils. Further, since the winding start portion of the electrode foil is remarkably bent (the radius of curvature is small), the electrode foil is cracked or easily broken, and a short mode is likely to occur.

However, in the case of the above-described wound electrolytic capacitor of Patent Document 1, the protective paper is disposed between the tab and the separator, but is provided at the winding start portion or winding end portion where the short mode is likely to occur. Absent.
For this reason, in the wound electrolytic capacitor disclosed in Patent Document 1, even if the occurrence of a short mode near the tab where current is concentrated can be suppressed, it is generated due to burrs at both ends (winding start portion and winding end portion) of the electrode foil. It is not possible to suppress the occurrence of a short mode that is easy to perform.

  Then, an object of this invention is to provide the manufacturing method of the winding type electrolytic capacitor which can suppress generation | occurrence | production of a short mode.

  The method for manufacturing a wound electrolytic capacitor of the present invention includes an insulating layer forming step of forming a plurality of insulating layers on the surface of a sheet of insulating strip at predetermined intervals in the length direction, A cutting step of cutting a strip of paper at a position where the insulating layer is formed to produce a plurality of separators each having the insulating layer disposed at both ends thereof, and the separator between the anode foil and the cathode foil And a winding step of starting winding from one end of the separator and finishing winding at the other end (first invention).

According to this configuration, since the insulating layers are formed on the surfaces of both end portions of the separator, occurrence of a short mode at the winding start portion and the winding end portion can be suppressed. Moreover, since the insulating property at both ends of the electrode foil is improved by providing the insulating layer, the withstand voltage of the wound electrolytic capacitor is improved.
Furthermore, since a plurality of insulating layers are formed on the surface of the band-shaped paper and then the band-shaped paper is cut together with the insulating layer to produce a separator having insulating layers formed at both ends, the band-shaped paper is After cutting into lengths, the manufacturing process can be simplified compared to the case where insulating layers are formed at both ends thereof.

In the method for manufacturing a wound electrolytic capacitor of the present invention, in the insulating layer forming step, the insulating layer may be formed by attaching insulating paper to the surface of the belt-like paper (second invention). .
According to this configuration, the method of sticking the paper on the surface of the belt-shaped paper is easy, so that the wound electrolytic capacitor can be stably produced.

  Insulating paper is kraft paper, cotton paper, Manila paper, hemp pulp paper, esparto paper, and mixed papers thereof (third invention), or vinylon fiber or vinylon fiber and glass fiber, polyester fiber , Nylon fibers, rayon fibers, and non-woven fabrics mixed with paper fibers are preferable (fourth invention).

Moreover, in the manufacturing method of the winding type electrolytic capacitor of this invention, you may form the said insulating layer by apply | coating insulating synthetic resin to the surface of the said strip | belt-shaped paper in the said insulating layer formation process ( (5th invention).
According to this configuration, an insulating layer having high adhesion to the separator can be formed.

  Insulating synthetic resins are epoxy resin, phenol resin, furan resin, melamine resin, xylene resin, guanamine resin, fluororesin, butadiene resin, polyamide resin, polyamideimide resin, polyarylate resin, polyimide resin, polyetherimide resin, poly It is preferably any of an ether ketone resin, a polycarbonate resin, a polyvinyl formal resin, a polyphenylene sulfide resin, a liquid crystal polymer, a ketone resin, a coumarone resin, and an MBS resin (sixth invention).

The wound electrolytic capacitor of the present invention is a wound electrolytic capacitor in which an anode foil and a cathode foil are wound via a separator, and an insulating layer is formed on each surface of both ends of the separator. (Seventh invention).
According to this configuration, since the insulating layers are formed on the surfaces of both end portions of the separator, occurrence of a short mode at the winding start portion and the winding end portion can be suppressed.
Moreover, since the insulating property at both ends of the electrode foil is improved by providing the insulating layer, the withstand voltage of the wound electrolytic capacitor is improved.

Since the insulating layer is formed in the surface of the both ends of a separator, the manufacturing method of the winding type electrolytic capacitor of this invention can suppress generation | occurrence | production of the short mode in a winding start part and a winding end part.
In addition, the insulating layer can be formed in one step at the winding end portion and the winding start portion of the next capacitor element, and the manufacturing process can be simplified as compared with the case where the insulating layer is formed separately.

Embodiments of the present invention will be described below.
The wound electrolytic capacitor 1 of the present embodiment includes a capacitor element 2, a cylindrical outer case (not shown) in which the capacitor element 2 is stored, and a sealing body (not shown) that seals the opening of the outer case. With.

  As shown in FIG. 1, the capacitor element 2 has a structure in which an anode foil 3 and a cathode foil 4 are wound around a winding core 7 via a separator 5.

  The anode foil 3 is made of a valve metal such as aluminum. The surface of the anode foil 3 is roughened by an etching process, and an anodized film by anodization (chemical conversion) is formed. The cathode foil 4 is also made of aluminum or the like, like the anode foil 3, and the surface thereof is roughened and an anodized film by anodization (chemical conversion) is formed or a natural oxide film is formed. Is formed.

  The separator 5 holds a driving electrolyte (not shown). As a result, the electrolyte is sandwiched between the anode foil 3 and the cathode foil 4. For the separator 5, an insulating paper having electrical insulation is used. As the insulating paper, for example, kraft paper, cotton paper, manila paper, hemp pulp paper, esparto paper, and mixed papers thereof may be used. However, vinylon fiber, or vinylon fiber and glass fiber, polyester fiber may be used. Further, a nonwoven fabric mixed with nylon fiber, rayon fiber, or paper fiber may be used.

  As shown in FIGS. 1 and 2B, an insulating layer 6 is formed on the surfaces of both end portions 5a and 5b of the separator 5, that is, the surfaces of the winding start portion 5a and the winding end portion 5b. The insulating layer 6 is made of insulating paper. Specifically, the insulating paper mentioned as the separator 5 described above can be used as the insulating paper.

An anode lead tab 8 and a cathode lead tab 9 are drawn out from the anode foil 3 and the cathode foil 4, respectively, and the anode lead wire 10 and the cathode lead wire 11 are connected to the anode foil 3 and the cathode foil 4 through the lead tabs 8 and 9, respectively. Are connected to each other.
The lead tab 8 (9) includes a flat tab portion 8a (9a) and a round bar-shaped connection portion 8b (9b) connected to one end of the tab portion 8a (9a). The tab portions 8a and 9a are respectively fixed to the surfaces of the anode foil 3 and the cathode foil 4 by welding or the like.

Next, a method for manufacturing the wound electrolytic capacitor 1 will be described.
First, as shown in FIG. 2A, a plurality of insulating layers 6 are formed at predetermined intervals in the length direction on the surface of one strip-shaped paper 12 for forming a separator (insulating layer forming step). ). Specifically, the above-mentioned insulating paper with a pressure-sensitive adhesive on the back surface is attached to the surface of the belt-like paper 12.

  Next, the belt-like paper 12 is cut at a position where the insulating layer 6 is formed (cutting step). Thereby, the some separator 5 with which the insulating layer 6 was formed in each both ends is produced.

  On the other hand, the metal foil for forming the anode foil and the metal foil for forming the cathode foil are subjected to etching treatment or anodizing treatment, and then cut into predetermined dimensions to produce the anode foil 3 and the cathode foil 4. As shown in FIG. 2 (b), tab portions 8 a and 9 a are fixed to the surfaces of both electrode foils 3 and 4, and lead wires 10 and 11 are attached to both electrode foils 3 and 4 via lead tabs 8 and 9. Connecting.

And the separator 5 is interposed between the anode foil 3 and the cathode foil 4, and it winds around the winding core 7 (winding process). At this time, the winding starts from the end 5a of the separator 5 and finishes winding at the end 5b.
Then, the capacitor | condenser element 2 is produced by being immersed in the electrolyte solution for a drive. And this capacitor | condenser element 2 is accommodated in an exterior case (illustration omitted), and the opening part of this exterior case is sealed by a sealing body (illustration omitted) in the state by which the lead wires 10 and 11 were pulled out.

According to the wound electrolytic capacitor 1 described above, since the insulating layers 6 are formed on the surfaces of both end portions 5a and 5b of the separator 5, respectively, between the electrode foils 3 and 4 at the winding start portion and the winding end portion. The occurrence of the short mode can be suppressed.
In addition, by providing the insulating layer 6, the insulating properties at both ends of the electrode foils 3 and 4 are improved, so that the withstand voltage of the wound electrolytic capacitor 1 is improved.
Further, after forming a plurality of insulating layers 6 on the surface of the strip-shaped paper 12, the strip-shaped paper 12 is cut together with the insulating layer 6 to produce the separator 5 in which the insulating layers 6 are formed at both ends 5a, 5b. Therefore, the manufacturing process can be simplified as compared with the case where the insulating layer 6 is formed at both ends 5a and 5b after the strip paper 12 is cut to a predetermined length.

  Moreover, since the method of sticking paper on the surface of the strip-shaped paper 12 is easy, the wound electrolytic capacitor 1 can be stably produced.

  Next, specific examples of the present invention will be described together with conventional examples.

[Examples 1 to 4] Affixing insulating paper on the surface of the strip-shaped paper 12 First, as shown in FIG. 2A, a plurality of insulating layers 6 are formed on the surface of a single strip-shaped paper 12 for forming a separator. It was formed at a predetermined interval in the length direction (insulating layer forming step). Specifically, an insulating paper with a pressure-sensitive adhesive on the back surface was affixed to the surface of the belt-like paper 12.
Kraft paper (Example 1), Manila paper (Example 2), hemp part paper (Example 3), and Kraft / Manila paper mixed (50/50) paper (Example 4) were used as the insulating paper.

  Next, the belt-like paper 12 was cut at a position where the insulating layer 6 was formed (cutting process). In this way, a plurality of separators 5 in which the insulating layers 6 were formed at both ends were produced.

  On the other hand, the metal foil for forming the anode foil and the metal foil for forming the cathode foil were subjected to etching treatment and anodizing treatment, and then cut into predetermined dimensions to produce anode foil 3 and cathode foil 4. As shown in FIG. 2 (b), tab portions 8 a and 9 a are fixed to the surfaces of both electrode foils 3 and 4, and lead wires 10 and 11 are attached to both electrode foils 3 and 4 via lead tabs 8 and 9. Connected.

And the separator 5 was interposed between the anode foil 3 and the cathode foil 4, and it wound around the winding core 7 (winding process). At this time, the winding was started from the end portion 5a of the separator 5 and finished at the end portion 5b.
Then, the capacitor | condenser element 2 was produced by being immersed in the electrolyte solution for a drive. And this capacitor | condenser element 2 was accommodated in the exterior case (illustration omitted), and the opening part of this exterior case was sealed by the sealing body (illustration omitted) in the state in which the lead wires 10 and 11 were pulled out.

[Examples 5 to 8] Insulating synthetic resin is applied to the surface of the strip-shaped paper 12 A plurality of insulating layers 6 are formed on the surface of a single strip-shaped paper 12 for forming a separator at predetermined intervals in the length direction. (Insulating layer forming step). Specifically, an insulating synthetic resin was applied to the surface of the strip paper 12.
As the insulating synthetic resin, an epoxy resin (Example 5), a phenol resin (Example 6), a fluororesin (Example 7), and a polyimide resin (Example 8) were used.
The insulating synthetic resin (thermosetting resin or thermoplastic resin) was cured by heating or solidified by cooling after the winding process.

(Conventional example)
As a conventional example, a wound electrolytic capacitor was produced in the same procedure as in Examples 1 to 8, except that the above insulating layer was not provided on the surface of the belt-like paper 12.

  With respect to the above-described wound electrolytic capacitors of Examples 1 to 8 and the conventional example, the number of occurrences of the short mode and the occurrence location when an overvoltage of 1.5 times the rated voltage was applied were examined. The results are shown in Table 1. The number of tests was 100 in all cases.

  As is apparent from Table 1, the winding type electrolytic capacitors of Examples 1 to 8 in which the insulating layers are formed at both ends of the separator have 0 occurrences of the short mode, which is a conventional winding type electrolytic capacitor. It turns out that it is superior.

In the above embodiment, kraft paper, manila paper, hemp part paper, kraft / manila paper mixed paper (50/50) paper is used as insulating paper, but cotton paper and esparto paper can also be used. Also, two or more kinds of craft paper, cotton paper, manila paper, hemp pulp paper, and esparto paper can be appropriately mixed and used.
In addition, as the insulating paper, it is also possible to use vinylon fibers or a nonwoven fabric obtained by mixing vinylon fibers and glass fibers, polyester fibers, nylon fibers, rayon fibers, or paper fibers.

In the above embodiment, epoxy resin, phenol resin, fluororesin, and polyimide resin are used as the insulating synthetic resin. However, other than this, thermosetting resins such as furan resin, melamine resin, xylene resin, and guanamine resin can be used. , Butadiene resin, polyamide resin, polyamideimide resin, polyarylate resin, polyetherimide resin, polyetherketone resin, polycarbonate resin, polyvinyl formal resin, polyphenylene sulfide resin, liquid crystal polymer, ketone resin, coumarone resin, MBS resin, etc. These thermoplastic resins can be used.
In this case, an insulating synthetic resin is applied to the surface of the strip-shaped paper 12 in the insulating layer forming step. Thereby, the insulating layer 6 having high adhesion to the separator 5 can be formed.

Further, in the manufacturing process of the wound electrolytic capacitor 1 according to the above embodiment and the examples, the insulating layer 6 is formed on the surface of the belt-like paper 12 and then cut to produce the separator 5. Winding with. That is, the insulating layer forming step, the cutting step, and the winding step are performed in this order, but the method for manufacturing the wound electrolytic capacitor is not limited to this order.
For example, you may perform an insulating layer formation process, a cutting process, and a winding process simultaneously. Specifically, the belt-like paper 12 having the insulating layer 6 formed at one end and the electrode foils 3 and 4 are overlapped and wound so as to start winding from the end portion where the insulating layer is formed. In the middle of winding, the insulating layer 6 is formed at a predetermined position of the belt 12, that is, at a position where the winding end portion 5 b of the separator 5 and the winding start portion 5 a of another separator 5 are formed. Thereafter, the belt-like paper 12 is cut together with the insulating layer, and the winding is finished at the end portion where the insulating layer 6 is formed.

  Moreover, although this embodiment and an Example are examples which applied this invention to the winding type non-solid electrolytic capacitor, the application object of this invention is not limited to such a non-solid electrolytic capacitor. For example, the present invention can be applied to a winding type solid electrolytic capacitor.

1 is an exploded perspective view of a capacitor element of a wound electrolytic capacitor according to the present invention. (A) shows the strip-shaped paper before the cutting step, and (b) shows a development view of the capacitor element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Winding type electrolytic capacitor 2 Capacitor element 3 Anode foil 4 Cathode foil 5 Separator 6 Insulating layer 7 Core 8 Anode lead tab 9 Cathode lead tab 10 Anode lead wire 11 Cathode lead wire

Claims (6)

An insulating layer forming step of forming a plurality of insulating layers on the surface of a sheet of insulating strip with a predetermined interval in the length direction;
A cutting step of cutting the belt-like paper at a position where the insulating layer is formed, and producing a plurality of separators in which the insulating layer is disposed at both ends thereof,
A winding step of interposing the separator between the anode foil and the cathode foil, starting winding from one end of the separator and finishing winding at the other end;
A method for manufacturing a wound electrolytic capacitor, comprising: In the insulating layer forming step,
The method for manufacturing a wound electrolytic capacitor according to claim 1, wherein the insulating layer is formed by attaching insulating paper to the surface of the belt-like paper.   The method for producing a wound electrolytic capacitor according to claim 2, wherein the insulating paper is any one of craft paper, cotton paper, manila paper, hemp pulp paper, esparto paper, and mixed paper thereof. .   3. The wound electrolysis according to claim 2, wherein the insulating paper is vinylon fiber or a nonwoven fabric obtained by mixing vinylon fiber and glass fiber, polyester fiber, nylon fiber, rayon fiber, or paper fiber. Capacitor manufacturing method. In the insulating layer forming step,
The method for manufacturing a wound electrolytic capacitor according to claim 1, wherein the insulating layer is formed by applying an insulating synthetic resin to the surface of the belt-like paper.   The insulating synthetic resin is epoxy resin, phenol resin, furan resin, melamine resin, xylene resin, guanamine resin, fluororesin, butadiene resin, polyamide resin, polyamideimide resin, polyarylate resin, polyimide resin, polyetherimide resin, 6. The wound electrolytic capacitor according to claim 5, wherein the wound electrolytic capacitor is one of a polyether ketone resin, a polycarbonate resin, a polyvinyl formal resin, a polyphenylene sulfide resin, a liquid crystal polymer, a ketone resin, a coumarone resin, and an MBS resin. Manufacturing method.

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