JP2019102580A - Electrolytic capacitor and method of manufacturing the same - Google Patents

Abstract

To provide an electrolytic capacitor capable of suppressing foil cracking and distortion from irregularly occurring in an electrode foil and also capable of suppressing the generation of punch scraps, in a configuration where the electrode foil and a lead tab are connected by caulking, and a method of manufacturing the same.SOLUTION: A method of manufacturing an electrolytic capacitor includes the steps of: forming a gap 31 in an electrode foil 3; and overlaying a lead tab 5 on the electrode foil 3, sticking a caulking needle 21 into the gap 31 from a lead tab side to be penetrated therethrough, and, after causing burrs 7a of the lead tab 5, crushing the burrs 7a by a press, thereby connecting the electrode foil 3 and the lead tab 5 by caulking.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an electrolytic capacitor and a method of manufacturing the same, and to an electrolytic capacitor in which an electrode foil and a lead tab are connected by caulking and a method of manufacturing the same.

  Conventionally, in the process of manufacturing a wound electrolytic capacitor in which an electrode foil (anode foil and a cathode foil) is wound with an electrolytic paper (separator) sandwiched between, when physically and electrically connecting the electrode foil and the lead tab A method called caulking connection method is used.

  As this caulking connection method, for example, as described in Patent Documents 1 and 2, in a state where lead tabs are overlapped on electrode foil and these are held between a support and a pressing plate, caulking needles are used as lead tabs. There is known a method in which the electrode foil and lead tab stacked from the side are pierced and burrs of the lead tab are generated on the side where the clamp needle pierces, and then the clamp needle is pulled out and the burr is crushed by a press.

  Specifically, as shown in FIG. 8, the lead tab 105 is superimposed on the electrode foil 103 (FIGS. 8A and 8B), and these are held by a support and a pressing plate (not shown) from the lead tab side The caulking needle 121 is pierced (FIG. 8 (c)), and after the burr 107a of the lead tab 105 is produced on the side where the caulking needle 121 pierced, the caulking needle 121 is pulled out (FIG. 8 (d)). The press 107a is crushed (FIGS. 8 (e) and (f)).

  Further, as another conventional caulking connection method, as shown in FIG. 9, after punching holes 113 in advance in the electrode foil 103 (FIG. 9A), the lead tab 105 is overlapped on the electrode foil 103 (FIG. 9) (B) After sticking the caulking needle 121 into the electrode foil 103 and the lead tab 105 superimposed from the lead tab side according to the position of the punched hole 113 (FIG. 9C, after generating the burr 107a of the lead tab 105) It is also known that the electrode foil 103 and the lead tab 105 are crimped and connected by pressing the burr 107a (FIG. 9 (d)) (FIG. 9 (e)).

JP, 2010-147336, A Unexamined-Japanese-Patent No. 2003-282364

  By the way, when the electrode foil 103 and the lead tab 105 are crimped and connected, there is a problem that the electrode foil 103 is broken depending on the type of the electrode foil 103 and the crimping condition.

  Specifically, when the crimp needle 121 pierces the lead tab 105 and the electrode foil 103, the electrode foil 103 is cracked, and stress in the subsequent steps leads to foil breakage, resulting in an electrical characteristic abnormality.

  Further, in the conventional caulking connection method, since the caulking needle pierces the electrode foil 103, as shown in FIG. 8 (f), the crack or strain of the electrode foil 103 is not generated around the caulking portion X1. As a result, there is a problem that the electrode foil 103 breaks through the electrolytic paper (separator) and a characteristic abnormality such as short circuit occurs.

  Further, in the method of providing the punched holes 113 shown in FIG. 9, punch scraps 114 (FIG. 9A) generated when forming the punched holes 113 in the electrode foil 103 stick to the electrode foil 103 or There was a problem that the discharge port for discharging the waste was clogged.

  The present invention, in a configuration in which electrode foil and lead tab are crimped and connected, can suppress generation of foil cracking and distortion in electrode foil and can suppress generation of punch scrap and an electrolytic capacitor, and a manufacturing method thereof. It is intended to be provided.

  The method of manufacturing an electrolytic capacitor according to the present invention is a method of manufacturing an electrolytic capacitor formed by crimp-connecting an electrode foil and a lead tab and winding the electrode foil, and forming a cut in the electrode foil; The lead tab is overlapped on the electrode foil, and a caulking needle is pierced from the lead tab side to pierce the cut to produce a burr of the lead tab, and then the burr is crushed by a press to form the electrode foil and And clamping the lead tab with the lead tab.

  According to this method, it is possible to manufacture the electrolytic capacitor in which the occurrence of the characteristic abnormality is suppressed by crimp-connecting the electrode foil and the lead tab in which the cuts are formed in advance.

  Further, the electrolytic capacitor of the present invention is an electrolytic capacitor comprising an electrode foil in which a lead tab is crimped and connected, wherein the electrode foil has a cut and the lead tab has a burr penetrating the cut, and the electrode The foil and the lead tab are crimped and connected in a state where the burr is crushed.

  According to this configuration, it is possible to suppress the occurrence of characteristic abnormality in the manufactured electrolytic capacitor.

  According to the electrolytic capacitor and the method of manufacturing the same of the present invention, in the configuration in which the electrode foil and the lead tab are crimped and connected, it is possible to suppress the foil from being cracked in the electrode foil and to suppress the generation of punch scraps. A capacitor and a method of manufacturing the same can be provided.

It is a sectional view showing the composition of the electrolytic capacitor concerning the embodiment of the present invention. It is a perspective view showing a capacitor element concerning an embodiment of the present invention. It is sectional drawing and the top view which show the crimp part which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing process of the electrolytic capacitor which concerns on embodiment of this invention. It is sectional drawing and top view with which it uses for description of the crimp connection method of electrode foil of an electrolytic capacitor, and lead tab which concern on embodiment of this invention. It is the schematic diagram and sectional drawing which show the cut | interruption formed in electrode foil which concerns on embodiment of this invention. It is a basic diagram which shows the cut line which concerns on other embodiment. FIG. 7 is a cross-sectional view for explaining a conventional caulking connection method. FIG. 7 is a cross-sectional view for explaining a conventional caulking connection method.

Hereinafter, embodiments of the present invention will be described in detail based on the attached drawings.
As shown in FIG. 1, the wound type electrolytic capacitor 1 in the present embodiment is mainly composed of a capacitor element 2, an outer case 12, and a sealing body 11.

  As shown in FIG. 2, in the capacitor element 2, the anode foil 3a and the cathode foil 3b subjected to the etching process and the oxide film formation process are wound via the separator (electrolytic paper) 4, and the element stopping tape 9 ( It is fixed in Figure 1).

  The capacitor element 2 is accommodated in a bottomed cylindrical outer case 12 (FIG. 1) after being impregnated with a driving electrolyte and / or a solid electrolyte.

  A sealing body 11 made of resin, rubber or the like is attached to the opening of the outer case 12, and the opening has a structure sealed by drawing.

  The lead wire 6 is welded to the lead tab 5 drawn out of the capacitor element 2 and drawn out through the sealing body 11. The outer case 12 is covered by a sleeve 13.

  In the capacitor element 2, the anode foil 3a is made of a valve metal such as aluminum, tantalum or niobium. The surface of the anode foil 3a is roughened by etching, and an anodized film is formed by anodic oxidation (formation).

  Further, the cathode foil 3b is also made of aluminum or the like as the anode foil 3a, and its surface is roughened and a natural oxide film is formed.

  The thickness of the anode foil 3a is, for example, 60 to 120 μm, and the thickness of the cathode foil 3b is, for example, 20 to 50 μm.

Further, the separator 4 is impregnated with an electrolytic solution containing a solvent mainly composed of an organic solvent, a solute consisting of an organic acid salt and an inorganic acid salt, and an additive such as a phosphorus compound. As a result, a liquid electrolyte layer is formed between the anode foil 3a and the cathode foil 3b. Furthermore, as another electrolyte, one in which a solid conductive polymer is formed between the anode foil 3a and the cathode foil 3b can also be used.
For the separator 4, insulating paper having electrical insulation is used.

  Lead tabs 5 are connected to the anode foil 3a and the cathode foil 3b by caulking, respectively.

  As shown in FIGS. 3 (a) and 3 (b), the lead tab 5 is connected to a round bar portion 5a protruding from the end face of the capacitor element 2 and one end of the round bar portion 5a. It comprises the flat part 5b to which the foil 3a and the cathode foil 3b are connected.

  The lead tab 5 is formed by pressing one end of a round bar-like member made of aluminum by a predetermined length to form a flat portion 5b, and making the remaining portion a round bar 5a.

  Moreover, the lead wire 6 is welded to the front-end | tip (end part on the opposite side to the flat part 5b) of the round bar part 5a.

  The length of the flat portion 5 b is substantially the same as the width of the electrode foil 3 and is, for example, 1 to 30 mm. The width of the flat portion 5 b is, for example, 1 to 3 mm, and the thickness of the flat portion 5 b is, for example, 0.1 to 2.0 mm.

  The flat portion 5 b is disposed on the surface of the electrode foil 3 over substantially the entire width of the electrode foil 3, and is connected to the electrode foil 3 by, for example, three crimped portions 7.

  The caulking part 7 squeezes the burr 7a generated by piercing the three caulking needles 21 (FIG. 5 (c)) from the side of the lead tab 5 in a state where the electrode foil 3 and the lead tab 5 are stacked. It is formed by A hole formed by the crimping needle 21 penetrating the electrode foil 3 and the lead tab 5 is referred to as a through hole 7 b. The through hole 7 b covers the hollow portion extending in the thickness direction of the lead tab 5 (flat portion 5 b) and the burr of the lead tab 5 penetrating the electrode foil 3 (covers the inner wall of the hole formed in the electrode foil 3 by the crimping needle 21). And the protruding portion from the flat portion 5 protruding into the hole.

The three crimped portions 7 are arranged at substantially equal intervals in the width direction of the electrode foil 3 (the direction of the arrow A in FIG. 3).
Next, the manufacturing process of the electrolytic capacitor 1 will be described with reference to the flowchart shown in FIG.

(Caching and winding process)
The lead tab 5 and the electrode foil (anode foil 3a, cathode foil 3b) are crimped and connected, and the electrode foil 3 is wound via the separator 4 to produce a capacitor element 2 (FIG. 2). (Step S101).

  In this crimping and winding process, as shown in FIG. 5A, a cross-shaped cut 31 is formed in advance with respect to the crimped position of the electrode foil 3 (the anode foil 3a and the cathode foil 3b). The cut 31 is formed at a position (crimping position) at which the crimping needle 21 pierces in the crimping step by the crimping needle 21 described later, and in the case of the present embodiment, the lead tab is formed by the three crimping portions 7. In order to crimp and connect the electrode foil 5 and the electrode foil 3, as shown in FIG. 6A, the electrode foil 3 is formed with cuts 31 at three locations corresponding to the crimped position. The cut 31 penetrates the electrode foil 3 as shown in FIG. 6 (b) showing a cross section taken along line B-B in FIG. 6 (a).

In the process of forming the cut 31, a cutter conforming to the shape of the cut 31 is used. Specifically, in the case of the present embodiment, the cross-shaped cutter 31 is used because the cross-shaped cut 31 is formed. By pressing the cutter 33 against the electrode foil 3 as shown in FIG. 5 (a), as shown in FIGS. 6 (a) and 6 (b), a cross-shaped cut 31 is formed in the electrode foil 3. Can.
As shown in FIG. 5A, the cut 31 has a configuration penetrating in the thickness direction of the electrode foil 3.

The flat portion 5b of the lead tab 5 is disposed on the electrode foil 3 in which the cut 31 is formed in this manner (FIG. 5 (b)). Then, from the upper side of the lead tab 5, the three crimped needles 21 aligned in the width direction of the electrode foil 3 are pierced into the flat portion 5b and the electrode foil 3 (FIG. 5 (c) to form the through holes 7b). A flat portion 5b and a petal-like burr 7a of the electrode foil 3 are produced on the electrode foil 3 side (FIG. 5 (d)).
In the case of the present embodiment, the tip of the crimping needle 21 is a square pyramid.

  Thereafter, the clamping needle 21 is pulled out, and the flat portion 5b of the lead tab 5 and the electrode foil 3 are pressed from above and below, as shown in (e) and (f) of FIG. The burr 7a is crushed to form the crimped portion 7, and the electrode foil 3 and the lead tab 5 are crimped and connected. At this time, the electrode foil 3 and the lead tab 5 are connected by winding the electrode foil 3 by the burrs of the flattened flat portion 5 b.

  In the caulking and winding process (step S101), next, the anode foil 3a and the cathode foil 3b are wound via the separator 4 to produce a columnar capacitor element 2 from which the lead wire 6 is drawn.

(Impregnation process)
The capacitor element 2 is impregnated with the driving electrolyte by depressurization, pressurization or the like (step S102). The impregnation time at this time varies depending on the size of the capacitor element 2 and the type of the driving electrolyte, but generally, the larger the element size, the longer the impregnation time. Thereafter, a certain amount of excess driving electrolyte is removed by a centrifuge.

(Assembly process)
The capacitor element 2 impregnated with the driving electrolyte is housed in the outer case 12 (FIG. 1), and the opening of the outer case 12 is sealed with the sealing body 11 in a state where the lead wire 6 is drawn outside. Air tightness is maintained, and then the assembly of the electrolytic capacitor 1 is completed by covering with the sleeve 13 (step S103).

(Aging process)
A direct current voltage is applied to the electrolytic capacitor 1 under high temperature to repair the oxide film damaged by cutting and winding of the foil (step S104), and the manufacturing process of the electrolytic capacitor 1 is completed.

  In the manufacturing process of the electrolytic capacitor 1 described above, in the step of crimp-connecting the lead tab 5 and the electrode foil 3 (anode foil 3a, cathode foil 3b), at a position where the crimping needle 21 pierces the electrode foil 3 The cuts 31 are formed in advance.

  In the caulking process, the caulking needle 21 is pierced through the lead 31 through the lead tab 5 and penetrates the cut 31 (FIG. 5 (c)). At this time, when the diameter of the caulking needle 21 pierced and pierced through the cut 31 is larger than the size of the cut 31, the electrode foil 3 has a tear corresponding to the diameter of the crimp 31 from the cut 31. Expand (Fig. 5 (d)).

  As described above, since it is possible to expand the fissure from the previously formed cut 31, the crimping needle 21 does not break through the electrode foil 3, and as a result, the application of stress to the electrode foil 3 is suppressed Be done.

  In addition, even when a split is expanded in the electrode foil 3 as the cut 31 is formed in the electrode foil 3 in advance, as the clamp needle 21 penetrates, the split is formed from the split 31 formed in advance. It will be extended to In the case of the present embodiment, by forming the cross-shaped split 31 in advance, the split is easily spread in the direction of the cross. Thus, depending on the shape of the pre-formed tears 31, the tears extending therefrom can be regularly spread easily, and the tears and distortions as described above with reference to FIG. It can suppress spreading irregularly.

  Incidentally, when the diameter of the caulking needle 21 pierced and pierced through the incision 31 is equal to or smaller than the size of the incision 31, the tear does not extend from the previously formed incision 31. Therefore, also in this case, it is possible to suppress the application of stress to the electrode foil 3 as the crimping needle 21 penetrates.

  Further, in the step of forming the cut 31, it is not necessary to punch and remove a part of the electrode foil 3 as compared with the case of forming the conventional punched hole 113 (FIG. 9). The generation of punch debris 114 (FIG. 9A) is eliminated.

  Therefore, while it can suppress that unnecessary foil crack and distortion 3c (Drawing 5 (d), (f)) spread irregularly from crimped part 7, adhesion to punch foil 114 to electrode foil 3, It can prevent that the problem of the clogging of the discharge port in a manufacturing facility arises.

  As a result, it is possible to suppress the occurrence of characteristic abnormalities such as a short in the electrolytic capacitor 1 to be manufactured, and to prevent the punch scrap 114 from causing a problem in the manufacturing equipment.

  Further, as compared with the conventional manufacturing process for forming the punched holes 113, the manufacturing process of the present embodiment may introduce a process for forming the cut 31 instead of forming the punched holes 113, and the manufacturing process is largely changed. The said electrolytic capacitor can be manufactured without doing.

  In the above embodiment, although the case of forming the cross-shaped cuts 31 in the anode foil 3a and the cathode foil 3b has been described, the shape of the cuts 31 is not limited to this, and for example, is shown in FIG. As described above, it is necessary to apply various shapes, such as Y-shaped (FIG. 7A), X-shaped (FIG. 7B), etc., as long as it is a cut that penetrates the anode foil 3a and the cathode foil 3b. Can.

  Moreover, in the above-mentioned embodiment, although the case where cut 31 was formed using a cutter was described, the method of forming cut 31 is not restricted to this, for example, laser is made into anode foil 3a, cathode foil 3b Other methods can also be used, such as forming the cut 31 by irradiating the

  Moreover, in the above-mentioned embodiment, although the case where the anode foil 3a (cathode foil 3b) and the lead tab 5 were crimped and connected by the three caulking parts 7 was described, the number of caulking parts is limited to this. It is not a thing, but various numbers can be applied.

DESCRIPTION OF SYMBOLS 1 Electrolytic capacitor 2 Capacitor element 3 103 electrode foil 3 a anode foil 3 b cathode foil 4 separator 5 105 lead tab 5 b flat portion 7 caulking portion 7 a burr 7 b through hole 11 sealing body 12 outer case 13 sleeve 21 121 caulking needle 31 Cut 33 cutter

Claims (2)

A manufacturing method of an electrolytic capacitor comprising crimped connection between an electrode foil and a lead tab and winding the electrode foil,
Forming a cut in the electrode foil;
The electrode tab is overlapped with the lead tab, and a caulking needle is pierced from the lead tab side to pierce the cut to produce a burr of the lead tab, and then the burr is crushed by a press to form the electrode foil. And a step of crimp-connecting the lead tab and the lead tab. An electrolytic capacitor comprising an electrode foil having a lead tab crimped thereto, wherein
The electrode foil has a cut,
The lead tab has a burr passing through the cut,
The electrolytic capacitor is characterized in that the electrode foil and the lead tab are crimped and connected in a state where the burr is crushed.

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