JP3291840B2 - Aluminum electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a self-supporting aluminum electrolytic capacitor inserted into a printed circuit board used in general electronic equipment.

[0002]

2. Description of the Related Art A conventional aluminum electrolytic capacitor of this type is configured as shown in FIGS. 5 (a) and 5 (b).
That is, a high-purity aluminum foil is roughened to increase the surface area, and an anode foil formed by forming a dielectric oxide film on the surface by anodic oxidation, and a cathode foil made of aluminum foil with a separator interposed therebetween. The capacitor element 1 is formed by winding, and the capacitor element 1 is impregnated with a driving electrolyte, and a lead 2 pulled out from the capacitor element 1 is attached to a sealing member 3 by a claw shape. Then, the capacitor element 1 is housed in an aluminum metal case 5 having a bottomed cylindrical shape, and the opening is opened in the metal case 5. The member 3 is mounted and sealed, and the outer surface of the metal case 5 is covered with an outer sleeve 6 made of vinyl chloride. Configured to have.

When the aluminum electrolytic capacitor is mounted on a printed circuit board and used, as shown in FIG. 6, a "L" shaped external metal terminal 4 having a claw shape of the aluminum electrolytic capacitor is connected to the printed circuit board 7. And soldering is performed.

As shown in FIGS. 7A and 7B, the external metal terminal 4 and the sealing member 3 are attached by first inserting a rivet 9 into a hole 4 a provided in the external metal terminal 4. The flange 9a of the rivet 9 is welded to the external metal terminal 4 to connect the two 9 and 4, and then the rubber 10 forming the sealing member 3 and the hole 10 formed in the bake plate 11 are formed.
The rivet 9 is made to penetrate through the rivet 9 through the holes 10a and 11a.
2 and the capacitor element 1
This is performed by fitting the hole 2 a of the lead 2 pulled out from the rivet 9 and then caulking the tip of the rivet 9.

[0005]

However, the external metal terminal 4 in the above-mentioned conventional aluminum electrolytic capacitor is not used.
Is formed in a "U" shape having a claw shape as shown in FIG. 6, so that when inserted into the hole 8 of the printed circuit board 7, the clinch force of the external metal terminal 4 acts. In this case, When the thickness of the printed circuit board 7 is reduced, the above-mentioned clinching force of the external metal terminal 4 does not work effectively, so that the external metal terminal 4 is easily pulled out from the hole 8 of the printed circuit board 7 and the self-sustainability of the aluminum electrolytic capacitor is reduced. There was a problem that it was inferior.

Further, since the external metal terminal 4 is formed in a “U” shape having a claw shape, when the external metal terminal 4 is inserted into the hole 8 of the printed circuit board 7, the external metal terminal 4 is connected to the hole 8 of the printed circuit board 7. There is a gap between the terminal 4 and the gap. The gap also changes depending on the thickness of the printed circuit board 7.
When the thickness of the printed circuit board 7 becomes thinner than a predetermined thickness,
Since the contact position of the external metal terminal 4 in the shape of the letter "C" with the hole 8 of the printed circuit board 7 changes, the gap also changes. There has been a problem that variations occur in the height.

Further, the external metal terminal 4 is
A rivet 9 for caulking and connecting the lead 2 pulled out from the capacitor element 1 as shown in FIGS.
When the pressure in the metal case 5 rises during the high-temperature load test, the driving electrolyte impregnated in the capacitor element 1 is used to connect the rivet 9 to the rivet 9. In addition to the problem of leakage from the gap between the welded portion of the external metal terminal 9 and the external metal terminal 4, when a vibration test of the aluminum electrolytic capacitor is performed, the welded portion between the flange 9a of the rivet 9 and the external metal terminal 4 is broken. There is a problem that the number of parts increases and the cost increases.

The present invention solves the above-mentioned conventional problems. Even when the thickness of the printed circuit board changes, the external metal terminals are hardly removed, and the solderability and vibration resistance can be improved. It is an object of the present invention to provide an aluminum electrolytic capacitor which can prevent the leakage of the driving electrolyte during a high-temperature load test, and which is advantageous in terms of cost by reducing the number of parts.

[0009]

In order to achieve the above object, an aluminum electrolytic capacitor according to the present invention comprises a capacitor element having a lead, a bottomed cylindrical metal case which houses the capacitor element from one end opening. A sealing member for sealing an opening of one end of the metal case, and an external metal terminal attached to the sealing member, wherein the external metal terminal penetrates the sealing member to project toward the capacitor element side, and the lead lead Are connected to the rivet portion, and are formed integrally with the rivet portion and are attached to the printed circuit board so as to protrude on the side opposite to the capacitor element side. In which a serrated portion is formed in a portion to be inserted into the hole.

[0010]

According to the aluminum electrolytic capacitor having the above structure, the external metal terminal attached to the sealing member projects through the sealing member to the capacitor element side, and the rivet portion to which the lead lead pulled out from the capacitor element is connected. The rivet portion is formed integrally with the rivet portion, and is configured to include a mounting terminal portion to the printed circuit board protruding on the side opposite to the capacitor element side, and is inserted into a hole of the printed circuit board in the mounting terminal portion to the printed circuit board. Since the serrated portion is formed in the portion, when the terminal portion of the external metal terminal to be attached to the printed circuit board is inserted into the hole of the printed circuit board, the serrated portion of the attaching terminal portion is hardly uniformly inserted into the hole of the printed circuit board. As a result, even if the thickness of the printed circuit board changes, the holding force of the external metal terminal inserted into the hole of the printed circuit board does not change. , It becomes difficult to pull out, thereby improving the independence of the aluminum electrolytic capacitor.

In the soldering when the external metal terminal is inserted into the hole of the printed circuit board, the solder uniformly enters the saw-toothed portion of the mounting terminal, so that the solderability can be improved. Further, since the external metal terminal is always located substantially at the center of the hole of the printed circuit board, automatic mounting can be easily performed.

Further, since the external metal terminal is formed integrally with a rivet portion to which a lead lead drawn out from the capacitor element is connected and a mounting terminal portion to a printed circuit board, the conventional welded portion is eliminated. The leakage of the driving electrolyte due to the pressure rise in the metal case during the high-temperature load test is eliminated, the external metal terminals are not broken in the vibration test, and the number of parts is reduced, resulting in cost reduction. Advantageous ones can be obtained.

[0013]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1A and 1B show the overall structure of an aluminum electrolytic capacitor according to one embodiment of the present invention. Reference numeral 21 denotes a capacitor element.
1 is a method in which a high-purity aluminum foil is roughened to increase its surface area, and an anode foil formed by forming a dielectric oxide film on the surface by anodic oxidation and a cathode foil made of aluminum foil with a separator interposed therebetween. The capacitor element 21 is impregnated with a driving electrolyte.

The lead 22 pulled out from the capacitor element 21 is connected to an external metal terminal 24 attached to a sealing member 23 by caulking.
The capacitor element 21 in which the sealing member 23 is integrated in this manner is housed in an aluminum metal case 25 having a bottomed cylindrical shape, and the sealing is performed by attaching the sealing member 23 to the opening of the metal case 25. Thereafter, the outer surface of the metal case 25 is covered with an outer sleeve 26 made of vinyl chloride to constitute an aluminum electrolytic capacitor.

FIGS. 2A, 2B, and 2C show the structure of the external metal terminal 24. The external metal terminal 24 penetrates the sealing member 23 and protrudes to the capacitor element 21 side. The rivet portion 24a to which the lead 22 pulled out from the capacitor element 21 is connected and the mounting terminal portion 24b to the printed circuit board protruding on the side opposite to the capacitor element 1 side are integrally formed in a cylindrical shape from high-purity aluminum. A large-diameter rubber pressing portion 24c is integrally formed at the boundary between the rivet portion 24a and the mounting terminal portion 24b.

Reference numeral 24d denotes a saw-toothed portion provided on a portion of the mounting terminal portion 24b to be inserted into the hole of the printed circuit board. The sawtoothed portion 24d has a mounting terminal as shown in FIG. A portion 24e formed on the entire outer periphery of the portion 24b and located at the tip of the serrated portion 24d of the mounting terminal portion 24b is tapered from the middle and has a slightly rounded tip. The saw-toothed portion 24d of the mounting terminal portion 24b and the saw-toothed portion 2
The portion 24e located at the tip from 4d is subjected to solder plating.

FIG. 3 shows the external metal terminal 24 and the sealing member 2.
First, the rivet portion 24a of the external metal terminal 24 is connected to the rubber 27 constituting the sealing member 23.
And a hole 27a, 28a formed in the bake plate 28 is penetrated until the rubber pressing portion 24c hits the rubber 27, and a hole 29a of the washer 29 is fitted into the rivet portion 24a projecting from the hole 27a, 28a. Hole 22 of extraction lead 22 extracted from 21
a, and then, by caulking the tip of the rivet portion 24a, the external metal terminal 24 and the sealing member 2
3 is installed.

When the thus constructed aluminum electrolytic capacitor is mounted on a printed circuit board and used,
As shown in FIG. 4, the external metal terminals 24 are connected to the printed circuit board 30.
Is inserted into the hole 31 of the printed circuit board 30, even if the thickness of the printed circuit board 30 changes, the serrated portions 24d of the external metal terminals 24 are hardly uniformly inserted into the hole 31 of the printed circuit board 30. The retained holding force of the external metal terminal 24 does not change, and it is difficult for the external metal terminal 24 to come off.

When the soldering is performed in such a state that the saw-toothed portions 24d of the external metal terminals 24 are hardly uniformly inserted into the holes 31 of the printed circuit board 30, the solder is removed from the saw-toothed portions 24d.
, The solderability can be improved. Further, the external metal terminals 24 are always connected to the printed circuit board 3.
Since it is located substantially at the center of the hole 31 of 0, automatic mounting can be easily performed.

The mounting terminal 24b of the external metal terminal 24
24e located at the tip of the serrated portion 24d
Is formed to have a tapered shape in the middle, and the tip is slightly rounded, so that when the external metal terminal 24 is inserted into the hole 31 of the printed board 30, there is no problem that the printed board 30 is broken.

The external metal terminal 24 is integrally formed with a rivet portion 24a to which a lead 22 drawn from the capacitor element 21 is connected and a terminal portion 24b for attachment to a printed circuit board. The metal case 25 during the high temperature load test.
As a result, the driving electrolyte does not leak due to a rise in the pressure inside, and the external metal terminal 24 does not break in the vibration test, and the number of parts is reduced as compared with the conventional case. It is also very advantageous.

Table 1 shows a rating of 250 W using the external metal terminal 24 in the embodiment of the present invention and the external metal terminal 4 in the conventional example. V470μF, the size is 30mm in diameter,
Manufacture aluminum electrolytic capacitors with a length of 40mm,
This shows the test results when a ripple superposition test in which a ripple current of 1.12 A (60 Hz) is passed in a temperature atmosphere of 105 ° C. for 4000 hours.

[0024]

[Table 1]

As is apparent from Table 1, two out of 50 liquid leaks occurred in the conventional aluminum electrolytic capacitor, but in the aluminum electrolytic capacitor according to the embodiment of the present invention, 50 out of 50 liquid leaks occurred. It is clear that the sealability is improved.

Table 2 shows that the aluminum electrolytic capacitor according to the embodiment of the present invention shown in Table 1 and the conventional aluminum electrolytic capacitor have a frequency of 10 to 55 Hz and a reciprocation of 1 minute in XYZ directions for 2 hours each for a total of 6 times. It shows a test result when a time vibration test was performed.

[0027]

[Table 2]

As is clear from Table 2, three out of 200 terminal breaks occurred in the conventional aluminum electrolytic capacitor, but in the aluminum electrolytic capacitor according to the embodiment of the present invention, 200 terminal breaks occurred. It is clear that the vibration resistance is improved.

[0029]

As described above, in the aluminum electrolytic capacitor of the present invention, the external metal terminal attached to the sealing member penetrates the sealing member, protrudes toward the capacitor element, and the lead lead drawn out from the capacitor element is connected. Rivet part, and formed integrally with this rivet part,
The mounting terminal portion to the printed circuit board protrudes to the side opposite to the capacitor element side, and the sawtooth-shaped portion is formed in a portion of the mounting terminal portion to the printed circuit board inserted into the hole of the printed circuit board. Therefore, when the mounting terminal portion of the external metal terminal to the printed circuit board is inserted into the hole of the printed circuit board, the saw-toothed portion of the mounting terminal portion is hardly uniformly inserted into the hole of the printed circuit board. Even if changes, the holding force of the external metal terminal inserted into the hole of the printed circuit board does not change and it is difficult to pull out,
The self-sustainability of the aluminum electrolytic capacitor can be improved.

Further, when the external metal terminal is inserted into the hole of the printed circuit board, the solder uniformly enters the saw-toothed portion of the mounting terminal portion, so that the solderability can be improved. Further, since the external metal terminal is always located substantially at the center of the hole of the printed circuit board, automatic mounting can be easily performed.

Further, the external metal terminal is formed integrally with a rivet portion to which a lead lead drawn out from the capacitor element is connected and a terminal portion for attachment to a printed circuit board, thereby eliminating a conventional welded portion. The leakage of the driving electrolyte due to the pressure rise in the metal case during the high-temperature load test is eliminated, the external metal terminals are not broken in the vibration test, and the number of parts is reduced, resulting in cost reduction. Advantageous ones can be obtained.

[Brief description of the drawings]

FIG. 1A is a plan view of an aluminum electrolytic capacitor showing one embodiment of the present invention. FIG.

2A is a plan view of an external metal terminal of the aluminum electrolytic capacitor. FIG. 2B is a half-sectional view of the external metal terminal. FIG.

FIG. 3 is a sectional view showing attachment of the external metal terminal and a sealing member.

FIG. 4 is a side sectional view showing the mounting of the aluminum electrolytic capacitor on a printed circuit board.

FIG. 5A is a plan view of an aluminum electrolytic capacitor showing a conventional example, and FIG.

FIG. 6 is a side sectional view showing the mounting of the aluminum electrolytic capacitor on a printed circuit board.

FIGS. 7A and 7B are exploded cross-sectional views showing attachment of an external metal terminal and a sealing member in the aluminum electrolytic capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Capacitor element 22 Leader lead 23 Sealing member 24 External metal terminal 24a Riveted part 24b Mounting terminal part 24d Serrated part 25 Metal case 30 Printed circuit board 31 Hole

Continuing on the front page (72) Inventor Ikunori Kawamura 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Hiroshi Kurimoto 1006 Odaka Kadoma Kadoma City, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (56 References JP-A-62-78739 (JP, A) JP-B-30-5478 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01G 9/00-9/28

Claims (1)

(57) [Claims] 1. A capacitor element having a lead-out lead, a bottomed cylindrical metal case which houses the capacitor element from one end opening, a sealing member for sealing one end opening of the metal case, and A rivet portion having an external metal terminal to be attached, penetrating the external metal terminal through a sealing member, and projecting toward the capacitor element side, and connected to the lead-out lead; An aluminum electrolytic capacitor, comprising: a mounting terminal portion for mounting on a printed circuit board protruding on the opposite side to the opposite side, wherein a serrated portion is formed in a portion of the mounting terminal portion for mounting on the printed circuit board which is inserted into a hole of the printed circuit board.