JP2002043176A - Aluminum electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase reliability of an electrolytic capacitor by reducing a contact resistance between outgoing leads and terminals. SOLUTION: After a sealing plate 15, provided with the terminals 16 and the outgoing leads 14 extended from a capacitor element 13, are connected to each other and then the capacitor element 13 is stored in an outer jacketing case 11, the sealing plate 15 is set in an opening 11a of the outer packaging case 11 to seal the capacitor element 13, to complete an aluminum electrolytic capacitor. In this aluminum electrolytic capacitor, the outgoing leads 14 and internal terminals 16a, 16b of the terminals 16 are connected by calking, and the parts of the outgoing leads 14 and the internal terminal 16a are laser-welded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum electrolytic capacitor capable of stably performing metal joining between a lead and an internal terminal of the aluminum electrolytic capacitor.

[0002]

2. Description of the Related Art A conventional aluminum electrolytic capacitor of this type has a terminal 16 in which a lead 14 of a capacitor element 13 is attached to a sealing plate 15 as shown in FIG.
7, a washer 17 is attached to the lead 14 and then brought into contact with the internal terminal 16a of the sealing plate 15, and the internal terminal 16b is pressed and fixed by crimping. I have.

However, the lead 14 and the terminal 16 have a large contact resistance due to mechanical joining by pressure welding via an aluminum washer 17, and as a result, during charging and discharging when a large current is applied to the capacitor, etc. There was a problem that heat was generated and electrical corrosion occurred, and the capacitor was opened.

[0004]

In order to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. 2-265231 discloses FIG.
As shown in the figure, after the lead lead 14 and the internal terminal are crimped and joined, the leading end 14a of the lead lead is turned back and brought into contact with the crimped portion of the internal terminal, and an ultrasonic oscillator having a knurled end surface is used. The method of ultrasonically joining the leading end 14a of the extraction lead and the crimped portion of the internal terminal 16b has been adopted. However, when analyzing the joint by ultrasonic waves, the interface between the two metals can be clearly observed. The metal bonding of both was inadequate. In general, the lead lead 14 has a lower material strength than the terminal 16, and when mechanical vibration such as ultrasonic vibration is applied, there is a problem that the lead lead 14 is cracked. In order to obtain this, it is necessary to increase the thickness of the extraction lead, and there has been a demand for a connection method in which the contact resistance between the extraction lead and the internal terminal is suppressed without changing the thickness of the extraction lead.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. As shown in FIGS.
After crimping and connecting the internal terminals,
The lead lead and the internal terminal can be metal-joined by laser welding the internal terminal 16a and the internal terminal 16a, so that contact resistance can be suppressed and heat generation can be reduced even when a large current flows.
That is, the sealing plate 15 provided with the terminal 16 is connected to the lead 14 drawn out from the capacitor element 13, the capacitor element 13 is stored in the outer case 11, and the sealing plate is inserted into the opening 11 a of the outer case 11. 15 is inserted and sealed in the aluminum electrolytic capacitor.
6a and 16b are caulked and joined, and a part of the lead 14 and the internal terminal 16a are laser welded.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS After crimping and joining a lead and an internal terminal, a laser welding machine is used to laser-weld a part of the lead and the internal terminal, whereby sufficient metal joining can be performed. As a result, the contact resistance between the lead and the terminal is reduced, so that even if a large current flows through the capacitor, heat generation due to the contact resistance can be suppressed.

[0007]

An embodiment of the present invention will be described with reference to the drawings. In FIG. 2, a bottomed cylindrical outer case 11 having an opening 11a at one end is provided with a fixing member 12 made of polypropylene resin inside, and a capacitor element 13 is provided between the fixing member 12 through the one end opening 11a. It is decorated.

[Embodiment 1] As shown in FIG. 1, a driving electrolyte is impregnated into a capacitor element 13 from which a plurality of lead leads 14 are drawn out from one side, and an inside of a phenol resin sealing plate 15 having a terminal 16 is provided. The terminal and the lead-out lead are joined by caulking via an aluminum washer 17. Further, as shown in FIGS. 3 and 4, the leading end 14a of the lead lead and the internal terminal 16a were laser-welded. A molten polypropylene resin is injected into the outer case 11 as the fixing member 12,
The capacitor element to which the sealing plate is connected is inserted into the outer case, the outer case 11 is sealed via the rubber ring 18, and the rated voltage is 450 V / 10,000 μF, and the size is φ9.
Ten capacitors of 0 × 190 mmL were produced.

[Embodiment 2] Leader lead 14 and internal electrode 1
After caulking and joining 6a and 16b, as shown in FIGS. 5 and 6, the lead 14 and the internal electrodes 16a and 16b were laser-welded in the vicinity of the caulked portion, and 10 capacitors were manufactured under the same conditions as the other conditions.

An aluminum electrolytic capacitor having only a crimped joint as a conventional example, and Japanese Patent Application Laid-Open No. 2-2652 as a comparative example.
No. 31, ten aluminum electrolytic capacitors were formed by crimping and ultrasonic bonding after crimping, and together with Examples 1 and 2, a peak current of 2500 A and a charging condition of 1 were used.
A charge / discharge test was performed at 250 V for 6 seconds and discharge conditions: complete discharge (0 V) for 4 seconds, and the results shown in Table 1 were obtained. The charge / discharge test was repeated up to 100,000 times, and the test was stopped when an abnormality occurred in 5 out of 10 capacitors.

[0011]

[Table 1]

In the conventional example, since the contact resistance between the lead and the terminal is large, electrical corrosion is caused between the lead and the terminal, and the open state occurs at 9,987 times. Further, in the comparative example, the lead wires having the same thickness as those in Examples 1 and 2 and the conventional example were used. However, because the sufficient metal bonding was not obtained by the ultrasonic bonding, an open state was obtained 65,052 times. . However, Examples 1 and 2
Although charge and discharge were repeated 100,000 times, no electrical corrosion occurred and no abnormality was observed.

[0013]

As is apparent from the above description, in the aluminum electrolytic capacitor according to the present invention, after crimping and joining the lead and the internal terminal, the lead and the internal terminal are laser-welded using a laser welding machine. It is possible to make a strong joint by bonding both metals, and to improve the reliability by reducing the contact resistance etc. and extend the life of the aluminum electrolytic capacitor It is.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a connection state between a terminal of a sealing plate and an extraction lead of an aluminum electrolytic capacitor according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a typical aluminum electrolytic capacitor.

FIG. 3 is an enlarged view of a joint of the embodiment of FIG. 1;

FIG. 4 is a sectional view taken along line aa of FIG.

FIG. 5 is an enlarged view of a joint according to another embodiment of the present invention.

FIG. 6 is a sectional view taken along line bb of FIG. 5;

FIG. 7 is an enlarged sectional view of a joint according to a conventional example.

FIG. 8 is an enlarged cross-sectional view of a joined portion by crimping ultrasonic joining disclosed in Japanese Patent Application Laid-Open No. 2-265231.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 outer case 11a one end opening of outer case 12 fixing member 13 capacitor element 14 extraction lead 14a extraction lead tip 15 sealing plate 16 terminal 16a internal terminal 16b internal terminal (caulking portion) 17 washer 18 rubber ring A laser welding point B Ultrasonic joint

Claims (1)

[Claims] 1. A sealing plate provided with a terminal is connected to an extraction lead drawn from a capacitor element, and the capacitor element is stored in an outer case. Then, the sealing plate is fitted into an opening of the outer case, and the sealing plate is sealed. An aluminum electrolytic capacitor, comprising: a crimping connection between the extraction lead and an internal terminal of the terminal; and a laser welding of a part of the extraction lead and the internal terminal.