JPH0499307A - Method of ultrasonic welding electrode foil to extraction terminal at aluminum electrolytic capacitor; anvil used for this method; extraction terminal connected to electrode foil by this method - Google Patents

Abstract

PURPOSE:To prevent a defective product from being produced by a burr near the bonding part of an electrode foil to an extraction terminal by a method wherein an anvil is pressed in such a way that a gap is not formed between a valley on an uneven face at the anvil encroaching on the extraction terminal and the extraction terminal and the extraction terminal is held. CONSTITUTION:An ultrasonic welding operation is executed in the following manner: an electrode foil 3 is arranged on a horn 1; an extraction terminal 14 is placed on it; an anvil 12 is arranged on it; the anvil 12 is pressed down; the electrode foil 3 and the extraction terminal 14 are sandwiched between the horn 1 and the anvil 12; while the anvil 12 is being pressed down by a pressure appropriate for each material, the horn 1 is oscillated and vibrated at an ultrasonic frequency; and the contact face 15 between the electrode foil 3 and the extraction terminal 14 is welded. The height (the depth of a valley) A of a top 12b on the uneven face 12a at the anvil 12 is set to a height which does not form a gap between the face 14b of the extraction terminal 14 and a valley 12c at the anvil 12 when the anvil is pressed at the pressure appropriate for each material. As a result, even when a burr is formed during a process in which the top 12b encroaches on the extraction terminal 14, it is crushed and disappears.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of connecting an electrode foil and a lead terminal of an aluminum electrolytic capacitor, particularly to a method of connecting using ultrasonic waves.

[Prior Art] In small aluminum electrolytic capacitors, ultrasonic welding is sometimes used instead of stitching connections because the electrode foils and lead terminals are small.

In ultrasonic welding, an electrode foil 3 and a lead-out terminal 4 to be ultrasonically welded to each other are placed between a horn (oscillator) 1 and an anvil (fixed base) 2, as shown in FIGS. 8 and 9. , push down the anvil 2 toward the horn 1, sandwich the lead-out terminal 4 and the electrode foil 3 between the anvil 2 and the horn 1, and press the anvil 2 downward while making the horn 1 oscillate to emit ultrasonic waves in the direction of arrow C. The contact surface between the electrode foil 3 and the lead-out terminal 4 is welded by vibration. Note that there is also a method of fixing the anvil and moving the horn toward the anvil to apply pressure.

A jagged uneven surface 1a is provided on the surface of the horn 1 that is in contact with the electrode foil 3, and this uneven surface 1a makes the electrode foil 3 wave-like and holds the electrode foil 3 so that it does not shift from the horn 1. To form a welding surface that is easy to weld. On the other hand, the surface of the anvil 2 in contact with the lead-out terminal 4 is also provided with jagged unevenness 2a consisting of peaks and valleys, so that the anvil 2 bites into the lead-out terminal 4 and holds and fixes the lead-out terminal 4.

[Problems to be Solved by the Invention] The distance (pitch) between the ridges of the jagged unevenness 28 of the anvil 2 is set to, for example, 0.3 mm, and the height of the ridges (depth of the valley) is set to 0.3 mm. It is made to be approximately 15/100 mm to accommodate electrode foils and lead terminals.

As such an anvil 2 is pressed against the lead-out terminal 4, as shown in FIG. Although the drawer terminal 4 is held, since the unevenness 2a is only partially dug in, when the drawer terminal 4 is separated from the anvil 2, there is a paris 4 on the surface 4a of the drawer terminal 4 as shown in FIG.
b occurs.

When the anode and cathode electrode foils 3 to which the lead terminals 4 are welded are wound with a separator in between to form a capacitor, the electrode foil 4b breaks through the separator and comes into contact with the electrode foil 3 of a different polarity, causing a short circuit. This may result in defective products.

This invention is based on i! The purpose is to prevent the production of defective products due to flakes near the joint with the electrode foil lead terminal.

[Means for Solving the Problems] In order to achieve this object, in the present invention, an anvil having an uneven surface consisting of peaks and valleys is pressed against the lead terminal to hold the lead terminal while the electrode foil and the lead terminal are connected. In the ultrasonic welding method, the anvil is held so that the anvil is pressed so that there is no gap between the valley of the uneven surface of the anvil that bites into the lead terminal and the lead terminal.

In addition, in the anvil used for ultrasonic welding between the electrode foil and the lead terminal of an aluminum electrolytic capacitor, the surface in contact with the lead terminal has an uneven surface consisting of peaks and valleys, and during ultrasonic welding, the material of the lead terminal The uneven surface made up of peaks and valleys that cut into the drawer terminal when pressed in the direction of the drawer terminal with an appropriate pressure is configured to have a depth such that the valleys are completely in contact with the surface of the drawer terminal. .

Furthermore, during ultrasonic welding, the part of the lead-out terminal that was held by the uneven surface of the anvil that has ridges and troughs, except for the recesses formed by the ridges of the anvil's uneven surface, is connected to the surrounding surface of that part. They were constructed so that they were on the same plane.

[Function] When the anvil is pressurized and the peaks on the uneven surface dig into the lead terminal, the valleys will completely contact the lead terminal, and there will be no gap between the face of the lead terminal and the valleys, so the peaks will cut into the lead terminal. Even if a paris is formed in the process of encroaching, it is crushed and disappears.

Therefore, the lead terminal does not have any cracks or the like and is flush with the surrounding surface except for the recesses formed by the ridges of the uneven surface of the anvil.

[Embodiments] Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 7. Note that the same reference numerals are used for the same members as in the conventional example.

FIG. 1 shows an embodiment of an anvil used in the method of connecting an electrode foil and a lead terminal of an aluminum electrolytic capacitor according to the present invention. .2a is provided. The uneven surface 12a has peaks 12b and valleys 12c (FIG. 2) arranged in parallel. The height of the peak (depth of the valley) A is the first when the anvil is pressurized and bites into the lead-out terminal 14.
As shown in Figure 0 (traditional example), there is no gap between the surface of the lead terminal and the valley, and the height is such that the valley 12c is completely in contact with the lead terminal 14 as shown in Figure 3. . The angle B of the valley is, for example, approximately 90''.

The pressure applied to the anvil 12 varies, for example, in a range of about 1300 g to 2600 g depending on the material of the extraction terminal 14. The height of the peak (the depth of the valley) A is determined by the surface 14b of the pull-out terminal 14 and the anvil 1 when pressed with a pressure suitable for each material.
The height is such that there is no gap between the groove 12c and the valley 12c.

Therefore, when the material of the lead-out terminal 14 is soft and the pressure applied to the anvil 12 is weakened, the height of the peak 12b becomes lower.
When the material of the pull-out terminal 14 is hard and the pressing force is strong, the peak 12
The height of b is made high. Therefore, the anvil 12 will be replaced depending on the material of the extraction terminal 14, the pressure applied to the anvil 12, etc.

For example, when the pressure is about 1300g, the height of the mountain is 1
/100mm to 2/100mm, pitch 0.02
mm-0.04mm, when the pressure is about 2600g,
The height of the mountain is about 1/10 mm, and the pitch is about 0.2 mm.

In ultrasonic welding, the electrode foil 3 is placed on the horn 1, the lead-out terminal 14 is placed on top of it, the anvil 12 is placed on top of it, and the anvil 12 is pushed down to connect the electrode foil 3 and the lead-out terminal 14 to the horn. The contact surface 15 ( Fig. 5) is welded.

The height A of the peaks 12b of the uneven surface 12a of the anvil 12 (the depth of the valleys) is such that there is a gap between the surface 14b of the pull-out terminal 14 and the valleys 12c of the anvil 12 when pressed with a pressure suitable for each material. Since the height is such that the peak 12b digs into the lead-out terminal 14, even if a crack is formed, it will be crushed and disappear.

Therefore, as shown in FIGS. 4 and 5, the lead terminal 14 separated from the anvil 12 does not have any cracks or the like, and the surrounding surfaces except for the recesses 14c formed by the peaks 12b of the uneven surface 12a of the anvil. It becomes the same plane as 14b. Therefore, even if the anode and cathode electrode foils 3 to which the lead-out terminals 14 are welded are wound with a separator in between to form a capacitor, the separator will break through and come into contact with the electrode foils of different polarities, causing a short circuit. There's nothing to do.

Incidentally, the peaks and valleys of the uneven surface 12a of the anvil may not be continuous as shown in FIGS. 2 and 3, but flat portions 12d may be provided as shown in FIG. 6. In this case, the surface of the lead-out terminal 14 after the anvil is released is as shown in FIG.

The uneven surface 12a of the anvil 1 is not only flat in which the peaks 12b and valleys 12C are arranged in parallel, but also has square pyramidal peaks arranged in a grid or grid pattern, or diagonally intersecting. It may be arranged in a twill pattern.

[Effects of the Invention] As explained above, according to the present invention, the drawer terminal is pressed and held by the uneven surface of the anvil so that there is no gap between the valley of the uneven surface and the drawer terminal. Even if a burr is formed in the process of the ridges of the surface biting into the lead-out terminal, it is crushed, so that burr, etc. does not occur on the lead-out terminal, and there is no recess formed by the ridges of the uneven surface of the anvil at the lead-out end. Even if the anode and cathode electrode foils, which are flush with the surrounding surface and have their respective lead terminals welded, are wound with a separator in between, there is no burr, so the separator can be pierced and the electrode foils of different electrodes can come into contact with each other. This has the advantage that short circuits do not occur and the possibility of producing defective products is reduced.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an anvil used in the ultrasonic welding method of the present invention, Fig. 2 is a partially enlarged view of the uneven surface of the anvil, and Fig. 3 shows the anvil being pressurized and the uneven surface biting into the lead-out terminal. Figure 4 is a partial cross-sectional view of the lead-out end with the anvil removed, Figure 5 is a diagram showing the lead-out terminal with electrode foil ultrasonically welded, Figure 6 is another implementation. A partial cross-sectional view showing the state in which the anvil is pressurized and the uneven surface bites into the lead-out terminal, Figure 7 is a partial cross-sectional view of the lead-out end with the anvil separated, and Figure 8 shows ultrasonic welding. Figure 9 is a cross-sectional view taken along the line E-E in Figure 8, Figure 10 is a partial cross-sectional view showing a state in which the conventional anvil is pressurized and bites into the pull-out terminal, and Figure 11 is an explanatory diagram. 10 is a partial sectional view of the drawer end in a state where the anvil is separated from the state shown in FIG. 10. FIG. In the figure, 12 is an anvil, 12a is an uneven surface, 12b is a mountain,
12c is a valley, 14 is a lead-out terminal, 14b is a surface, and 14c is a recess.

Claims (3)

[Claims] (1) In a method of ultrasonically welding an electrode foil and a lead-out terminal while holding the lead-out terminal by pressing an anvil with an uneven surface consisting of peaks and valleys against the lead-out terminal, the uneven surface of the anvil that has bitten into the lead-out terminal is A method for ultrasonic welding of an electrode foil of an aluminum electrolytic capacitor and a lead-out terminal, characterized in that the lead-out terminal is held by pressing an anvil so that there is no gap between the valley and the lead-out terminal. (2) The anvil used for ultrasonic welding between the electrode foil and the lead terminal of an aluminum electrolytic capacitor has an uneven surface consisting of peaks and valleys on the surface in contact with the lead terminal, and during ultrasonic welding, the material of the lead terminal The uneven surface consisting of peaks and valleys that cut into the drawer terminal when pressed in the direction of the drawer terminal with a pressure suitable for Anvil used for ultrasonic welding of aluminum electrolytic capacitor electrode foil and lead terminal. (3) During ultrasonic welding, the part of the lead-out terminal that was held by the uneven surface of the anvil having ridges and valleys is removed from the area around that part, except for the recess formed by the ridges of the anvil's uneven surface. A lead-out terminal for an aluminum electrolytic capacitor that is ultrasonically welded to an electrode foil, and is characterized by being flush with the surface.