JPH08236401A - Aluminum electrolytic capacitor manufacturing method - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a method of connecting an electrode foil and a tab terminal in an aluminum electrolytic capacitor, which can be easily performed at low cost without complicating the process and has a small connection resistance. To aim. [Constitution] From the flat portion 12a side of the tab terminal 12 to the electrode foil 1
1. A stitch needle is pierced through so that the electrode foil 11 and the tab terminal 12 are formed by piercing the stitch needle.
The return of the flat portion 12a is crushed by a pair of press plates 14a and 14b provided with a convex portion 15 on at least one side to connect the electrode foil 11 and the flat portion 12a of the tab terminal 12 and at the same time by the convex portion 15. The electrode foil 11 and the flat portion 12a of the tab terminal 12 are directly metal-bonded to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an aluminum electrolytic capacitor used in various electronic devices, and more particularly to a method for connecting an electrode foil and a tab terminal.

[0002]

2. Description of the Related Art Generally, in this type of aluminum electrolytic capacitor, as shown in FIG. 6, a separator 3 is interposed between a pair of electrode foils 2 to which external lead-out tab terminals 1 are connected, and these are wound. To form a capacitor element 4, and after impregnating the capacitor element 4 with a driving electrolytic solution, the capacitor element 4 is housed in a cylindrical metal case (not shown) having a bottom, and The opening is sealed with a sealing body (not shown). As a method of connecting the external lead-out tab terminal 1 and the pair of electrode foils 2 in this type of aluminum electrolytic capacitor, the electrode foil 2 and the external lead-out tab terminal 1 are placed on the anvil.
The flat parts of the electrode foil 2 and the external lead tab terminal 1 are ultrasonically applied by applying ultrasonic vibration to the flat parts of the electrode foil 2 and the horn which are pressed with a predetermined pressure. A method of welding, and arranging the electrode foil 2 and the flat portion of the external pull-out tab terminal 1 on a flat lower mold in an overlapping manner,
A method of cold pressing the electrode foil 2 and the flat portion of the external lead-out tab terminal 1 by pressing with an upper die having a plurality of protrusions arranged in a line from the top thereof, and the electrode foil 2 and the external lead-out. The flat portion of the external tab terminal 1 is overlapped, and a stitch needle is penetrated from the flat portion side of the external lead-out tab terminal 1 so as to penetrate through the electrode foil 2. The flat portion of the pull-out tab terminal 1 is crushed by a press to crush the electrode foil 2
There is also a crimping method of crimping the tab terminal 1 for external drawing. The press in the caulking method described above is shown in FIG.
As shown in the perspective view of (a), it is composed of a metal plate having a smooth surface, and the lower press 5 and the upper press (not shown) connect the electrode foil 2 and the external lead tab terminal 1 to each other. By sandwiching and applying pressure, both 1 and 2 are pressure-bonded.

Among the above-mentioned three connection methods, the ultrasonic welding method and the cold pressure welding method have the drawback that the electrical joining is strong but the mechanical joining is weak, while the caulking method has the drawback that the mechanical joining is strong but the electrical joining is not performed. There was a drawback that the dynamic bonding was weak.

In order to make up for this drawback, in the past,
For example, Japanese Utility Model Publication No. 54-164866 and Japanese Utility Model Publication 1-1
As disclosed in Japanese Patent No. 04716, the caulking method and the cold pressure welding method or the ultrasonic welding method are carried out in a double manner, and as shown in Japanese Utility Model Laid-Open No. 57-73921, The return portion of the flat portion of the electrode foil 2 and the external lead-out tab terminal 1 caused by the penetration is cold-pressed.

[0005]

With the progress of miniaturization of electronic equipment, there is a strong need for miniaturization of aluminum electrolytic capacitors used in this electronic equipment. The aluminum electrolytic capacitor has a surface area increased by increasing the surface roughness of the electrode foil, thereby increasing the electrostatic capacity per unit volume and reducing the size. The connection between the roughened electrode foil and the external lead-out tab terminal is in an open state because the contact resistance is large and the electrical connection is unstable due to variations due to the above caulking method alone. May lead to.
In order to compensate for this drawback, as described above, the method of performing the caulking method and the cold pressure welding method or the ultrasonic welding method in a double manner, and the electrode foil 2 and the external lead-out tab terminal 1 generated by the penetration of the stitch needle are used. There is a method of cold pressure welding the return part of the flat part, but in the former case the process is duplicated and complicated, while in the latter case the return part that is cold pressure welded like a miniaturized aluminum electrolytic capacitor. However, it was very difficult to maintain the accuracy in the process for a small size.

The present invention solves the above-mentioned problems of the prior art. A highly reliable caulking connection can be easily performed at a low cost without complicating the process, and at the same time, the contact resistance between the electrode foil and the tab terminal is small. It is an object of the present invention to provide a method for manufacturing an aluminum electrolytic capacitor including a connection method.

[0007]

In order to achieve the above object, the method of connecting the electrode foil and the tab terminal in the aluminum electrolytic capacitor of the present invention is such that the flat portion of the tab terminal is placed on the electrode foil and the tab terminal is arranged. The stitch needle is penetrated from the flat part side of the so that the return of the flat part of the electrode foil and the tab terminal caused by the penetration of the stitch needle is applied to a pair of press plates provided with a convex part on at least one side. The electrode foil and the flat portion of the tab terminal are connected by being pinched and crushed, and the electrode foil and the flat portion of the tab terminal are directly metal-bonded by the convex portion.

[0008]

According to the above connection method, the flat portion of the tab terminal is placed on the electrode foil, the stitch needle is penetrated from the flat portion side of the tab terminal so as to penetrate the electrode foil, and the stitch needle is penetrated. The return of the flat portion of the electrode foil and the tab terminal caused by the crushed by a pair of press plates provided with a convex portion on at least one to connect the electrode foil and the flat portion of the tab terminal, the electrode foil by the convex portion Since the flat part of the tab terminal and the flat part of the tab terminal are directly metal-bonded, it is possible to perform caulking connection with high reliability with low contact resistance and small variation. Since it can be carried out only by conversion, the process can be performed at low cost without complicating the process as in the conventional case.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 1A and 1B are sectional views showing a method of connecting an electrode foil and a tab terminal in an aluminum electrolytic capacitor according to an embodiment of the present invention in the order of steps. First, as shown in FIG. The flat portion 12a of the tab terminal 12 is placed on the foil 11 in an overlapping manner, and then a stitch needle (not shown) is penetrated from the side of the flat portion 12a of the tab terminal 12 so as to penetrate the electrode foil 11. In this case, due to the penetration of the stitch needle, a barb 13 which is a burr is generated on one surface of the electrode foil 11 and the flat portion 12a of the tab terminal 12. This is then shown in Figure 1.
As shown in (a), a pair of metal press plates 14a,
It is moved to the gap between 14b. In this case, one of the pair of metal press plates 14a and 14b is pressed.
As shown in FIG. 2 (a), a plurality of trapezoidal protrusions 1 continuous in the longitudinal direction are formed on the surface of the surface a that is in contact with the electrode foil 11.
5 is formed. On the other hand, the surface of the other press plate 14b in contact with the flat portion 12a of the tab terminal 12 is flat. When the electrode foil 11 and the flat portion 12a of the tab terminal 12 are pressed against each other by the pair of press plates 14a and 14b, the barb 13 is crushed as shown in FIG. Petal-like folds 1 as shown
6 is formed and the flat portion 12 of the electrode foil 11 and the tab terminal 12 is formed.
a is connected. At the same time, in the portion of the electrode foil 11 where the flat portion 12a of the tab terminal 12 overlaps, as shown in FIGS. 1B and 2B, a plurality of convex portions formed on one press plate 14a. Groove 17 corresponding to 15
Are formed as traces. In the groove 17, the oxide film on the surface of the electrode foil 11 is destroyed and the electrode foil 11 and the flat portion 12a of the tab terminal 12 are directly metal-bonded to each other. It is a small and highly reliable caulking connection.

The height H of the convex portion 15 shown in FIG.
And the thickness D1 of the electrode foil 11 and the flat portion 1 of the tab terminal 12.
Since the thickness D2 of 2a is D1 ≦ H ≦ D1 + D2, the tab terminal 1 in the electrode foil 11 corresponds to the plurality of protrusions 15 formed on one press plate 14a.
The concave groove 17 formed as a trace in the portion overlapping with the flat portion 12a of 2 does not break through the flat portion 12a of the tab terminal 12 to form a hole, and the flat portion 12a of the tab terminal 12 in the electrode foil 11 is Figure 2 for non-overlapping parts
Since the concave groove 17 is not formed as shown in (b), the electrode foil 11 can be efficiently formed without damaging unnecessary portions.
The groove 17 is formed only in the contact portion between the flat portion 12a of the tab terminal 12 and the tab terminal 12.
Can be formed.

3 (a) and 3 (b) are plan views of respective steps showing another embodiment of the present invention. In this other embodiment, the surface of one press plate 14a contacting the electrode foil 11 is A plurality of projections 15 having a plurality of continuous tips in the longitudinal direction and having an acute angle mountain shape
a is formed.

4A and 4B and FIGS. 5A and 5B.
4 is a perspective view showing another embodiment of the present invention, and FIG.
(A) and (b) have a plurality of knurled protrusions 15b formed on the surface of one of the press plates 14a in contact with the electrode foil 11. 5A and 5B, the convex portions 15c are formed in a grid pattern on the surface of the one press plate 14a in contact with the electrode foil 11.

Incidentally, the above-mentioned convex portions 15, 15a, 15
The tip shapes of b and 15c are not limited to the shapes shown in the embodiments, and the tip may have an R shape.

In the first embodiment of the present invention, an electrode foil having a thickness D1 having a thickness D1 of 0.1 mm and a tab terminal having a flat portion thickness D2 of 0.2 mm after the surface is roughened by etching are formed in the first embodiment of the present invention. A press plate in which three convex portions having a height H of 0.12 mm which are continuous in the longitudinal direction are formed on the surface in contact with the electrode foil is used, and in Example 2 of the present invention, the surface in contact with the electrode foil is continuous in the longitudinal direction. Using a press plate having three convex portions with a height H of 0.08 mm, and using a press plate having a smooth surface without a convex portion on the surface in contact with the electrode foil in the conventional example, respectively. Caulking was performed and 100 samples were prepared for each. The results of measuring the contact resistance of the connection portion at this time are shown in (Table 1).

[0015]

[Table 1]

As can be seen from (Table 1), the contact resistance of the connection portion by caulking connection of Examples 1 and 2 of the present invention has a smaller average value than the contact resistance of the connection portion by caulking connection of the conventional example, And the standard deviation (variation) is small,
The caulking connection with high reliability can be performed. Particularly, as in the first embodiment of the present invention, the height H of the convex portion is D1 ≦ H ≦ D1 +.
When the relationship of D2 is satisfied, the contact resistance of the connection portion becomes smaller both in the average value and in the standard deviation (variation), as compared with the embodiment 2 of the present invention which is not satisfied.

[0017]

As described above, according to the method of connecting the electrode foil and the tab terminal in the aluminum electrolytic capacitor of the present invention, the flat portion of the tab terminal is superposed on the electrode foil, and the flat portion side of the tab terminal is connected to the electrode foil. Through the stitch needle, and the return of the flat portion of the electrode foil and tab terminal caused by the penetration of the stitch needle is crushed by a pair of press plates provided with a convex portion on at least one side to squeeze the electrode foil and the tab. Since the flat part of the terminal is connected and the convex part of the electrode foil and the flat part of the tab terminal are directly pressed and metal-bonded to each other, the contact resistance is small and the variation is small and highly reliable. Since the caulking connection can be performed frequently and the process can be performed by converting only the press plate from the conventional process, the process can be performed at low cost without complicating the process as in the past. That.

[Brief description of drawings]

FIG. 1A is a sectional view showing a method of connecting an electrode foil and a tab terminal in an aluminum electrolytic capacitor according to an embodiment of the present invention. FIG. 1B is a sectional view showing a state after the connection.

FIG. 2A is a perspective view showing a method of connecting the electrode foil and the tab terminal, and FIG. 2B is a perspective view showing a state after the connection.

FIG. 3 (a) is a plan view showing a method of connecting an electrode foil and a tab terminal in an aluminum electrolytic capacitor of another embodiment of the present invention (b) a plan view showing a state after the same connection.

FIG. 4 (a) is a perspective view showing a method for connecting an electrode foil and a tab terminal in an aluminum electrolytic capacitor according to still another embodiment of the present invention. FIG. 4 (b) is a perspective view showing a state after the connection.

FIG. 5 (a) is a perspective view showing a method for connecting an electrode foil and a tab terminal in an aluminum electrolytic capacitor according to still another embodiment of the present invention. FIG. 5 (b) is a perspective view showing a state after the connection.

FIG. 6 is a developed perspective view showing the configuration of a capacitor element in a conventional aluminum electrolytic capacitor.

FIG. 7 (a) is a perspective view showing a method of connecting an electrode foil and a tab terminal in a conventional aluminum electrolytic capacitor. FIG. 7 (b) is a perspective view showing a state after the connection.

[Explanation of symbols]

 11 Electrode foil 12 Tab terminal 12a Flat part 13 Return 14a, 14b A pair of press plates 15, 15a, 15b, 15c Convex part

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shigeyoshi Iwamoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A flat portion of a tab terminal is placed on an electrode foil in an overlapping manner, a stitch needle is penetrated from the flat portion side of the tab terminal so as to penetrate the electrode foil, and an electrode foil produced by the penetration of the stitch needle, and The return of the flat part of the tab terminal is sandwiched between a pair of press plates provided with a convex part on at least one side and crushed to connect the electrode foil and the flat part of the tab terminal,
A method for manufacturing an aluminum electrolytic capacitor in which the electrode foil and the flat portion of the tab terminal are pressed into contact with each other by the convex portion to directly perform metal bonding. 2. The convex portion provided on one of the pair of press plates,
It is provided on the press plate that is in contact with the electrode foil, and the relationship between the height H of this convex portion, the thickness D1 of the electrode foil, and the thickness D2 of the flat portion of the tab terminal is D1≤H≤D1 + D2. Item 1. A method for manufacturing an aluminum electrolytic capacitor according to item 1.