JPH08264393A - Lead type aluminum electrolytic capacitor - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to mount a lead type aluminum electrolytic capacitor by soldering on a printed circuit board of an electronic device in a stable state without tilting the lead type aluminum electrolytic capacitor, and (EN) Provided is a lead-type aluminum electrolytic capacitor which can be used in a state where there is no adverse effect on the capacitor characteristics such as an increase in leakage current during soldering. [Structure] A capacitor element 11 in which an anode foil 13 and a cathode foil 14 to which a lead member 12 is connected are wound with a separator 15 interposed therebetween, and a winding tape 16 is used for winding, and a capacitor element 11 is provided. The impregnated electrolytic solution 17, a bottomed case 18 for accommodating the capacitor element 11, an opening of the bottomed case 18, and a sealing body 19 penetrating the lead member 12 and led out to the outside. And a void portion 20 occupying 5% or more of the space is provided in the space surrounded by the bottomed case 18 and the sealing body 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead type aluminum electrolytic capacitor used in various electronic devices.

[0002]

2. Description of the Related Art In a conventional lead type aluminum electrolytic capacitor, as shown in FIG. 4, an anode foil 2 and a cathode foil 3 to which a lead member 1 is connected are wound with a separator 4 interposed therebetween, and are unwound. The capacitor element 6 wound with the tape 5 is impregnated with the electrolytic solution 7 and housed in the bottomed case 8, and the opening 9 of the bottomed case 8 has the lead member 1 penetrating therethrough. Was mounted and sealed.

[0003]

With the recent miniaturization, thinning, and multi-functionalization of electronic equipment, electronic circuits are inevitably required to have a high density, and electronic parts are also miniaturized, low-profile, and low-profile mounted. As a result, electronic components are being mounted by penetrating a lead member deeply into a printed circuit board until the main body directly contacts the printed circuit board surface.

However, in the lead-type aluminum electrolytic capacitor shown in FIG. 4, after mounting the capacitor body through the lead member 1 to the printed circuit board of the electronic device and then performing soldering, convective heat in the solder bath and the printed circuit board. Since the body of the capacitor is heated to a high temperature by the conduction heat through the electrolytic solution 7, the electrolytic solution 7 in the bottomed case 8 and impregnated into the capacitor element 6 expands in volume, and this volume expansion causes the internal space of the bottomed case 8 to expand. Is compressed to increase the internal pressure, which causes the sealing body 9 to swell and deform. Due to this deformation, when the lead-type aluminum electrolytic capacitor is mounted on the printed circuit board of the electronic device, the lead-type aluminum electrolytic capacitor is tilted. In addition to the problem that the electrolytic capacitor is mounted, this deformation also causes the lead member 12 to be pulled outside. It is to join the stress, thereby, has a problem that adversely affects the capacitor characteristics such as leakage current increases.

The present invention solves the above-mentioned problems of the prior art by mounting a lead type aluminum electrolytic capacitor on a printed circuit board of an electronic device by soldering in a stable state without tilting the lead type aluminum electrolytic capacitor. An object of the present invention is to provide a lead-type aluminum electrolytic capacitor which can be carried out and which does not adversely affect the capacitor characteristics such as an increase in leakage current during soldering.

[0006]

In order to achieve the above object, the lead-type aluminum electrolytic capacitor of the present invention has an anode foil and a cathode foil, to which lead members are connected, wound with a separator interposed between them, and the winding is stopped. The capacitor element, the electrolytic solution impregnated in the capacitor element, the bottomed case for housing the capacitor element, and the opening of the bottomed case are sealed, and the lead member is penetrated to the outside. The sealing body is led out, and a void portion occupying 5% or more of this space is provided in the space surrounded by the bottomed case and the sealing body.

[0007]

According to the lead-type aluminum electrolytic capacitor having the above-described structure, the space surrounded by the bottomed case and the sealing body is provided with the void portion occupying 5% or more of the space. Even if the electrolytic solution expands in volume during soldering when mounting to the bottom, the increase in internal pressure of the bottomed case due to the expansion is reduced by the void provided in the space surrounded by the bottomed case and the sealing body. As a result, the sealing body does not swell and deform, so the mounting of the lead-type aluminum electrolytic capacitor by soldering on the printed circuit board of electronic equipment is stable without the lead-type aluminum electrolytic capacitor tilting. Can be done in a state,
Moreover, it is possible to prevent adverse effects on the capacitor characteristics, such as an increase in leakage current during soldering.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a lead-type aluminum electrolytic capacitor according to an embodiment of the present invention. In FIG. 1, 11 is a capacitor element.
1 is an anode foil 13 and a cathode foil 14 to which lead members 12 are connected.
Are wound with a separator 15 interposed therebetween, and are wound with a winding stop tape 16, and an electrolytic solution 17 is applied to the capacitor element 11.
And is housed in the bottomed case 18, and the lead member 12 is placed in the opening of the bottomed case 18.
The lead member 12, the anode foil 13, the cathode foil 14, and the separator 15 are placed in the bottomed case 18 by mounting the sealing body 19 that has penetrated through and led out to the outside, and adjusting the impregnation amount of the electrolytic solution 17. , The winding stopper tape 16 and the electrolytic solution 17 are added together and the inner volume is equal to the total volume of the voids 20 provided in the bottomed case 18 and sealed. There is.

The volume of the void portion 20 provided in the bottomed case 18, that is, the void portion 20 provided in the space surrounded by the bottomed case 18 and the sealing body 19, is equal to that of the electrolytic solution 17 at the time of soldering. Considering the volume expansion (Table 1), as shown in Examples 1 to 3 of the present invention, the bottomed case 18 and the sealing body 19 are provided.
The volume of the space surrounded by 5%, 20%, and 40%.

FIG. 2 shows a lead type aluminum electrolytic capacitor according to another embodiment of the present invention. The same parts as those of the lead type aluminum electrolytic capacitor shown in FIG. Only the points will be explained. That is, in another embodiment shown in FIG. 2, the anode foil, the cathode foil, and the separator (all not shown) that constitute the capacitor element 11 are adjusted in length and wound to form the bottomed case 18. A void portion 20 is provided, and the volume of the void portion 20 is 20% of the volume of the space surrounded by the bottomed case 18 and the sealing body 19, as shown in Example 4 of the present invention (Table 1).
It was made.

FIG. 3 shows a lead type aluminum electrolytic capacitor according to still another embodiment of the present invention. The same parts as those of the lead type aluminum electrolytic capacitor shown in FIG. Only the differences will be described.
That is, the other embodiment shown in FIG.
1 from which the lead member 12 is pulled out and the sealing body 1
The gap portion 20 is provided in the bottomed case 18 by adjusting the gap 21 between the inner surface 9 and the inner surface of the bottom portion 9.
The volume of 0 is 20% of the volume of the space surrounded by the bottomed case 18 and the sealing body 19, as shown in Example 5 of the present invention (Table 1).

Further, (Table 1) shows, for comparison, a conventional example in which a void portion is not provided by adjustment in the bottomed case (voids are 5% or less).

Further, (Table 1) shows the lead type aluminum electrolytic capacitor in each of the above-mentioned embodiments of the present invention and the lead type aluminum electrolytic capacitor shown in the conventional example at 50V10.
Also shown are the results of soldering tests conducted by manufacturing 1000 pieces each with a μF rating.

[0014]

[Table 1]

As is clear from this (Table 1), in each of the examples of the present invention, the number of warpages of the sealing body was zero. That is, in the lead-type aluminum electrolytic capacitors of the respective embodiments of the present invention, since the void portion 20 is provided in the bottomed case 18 by adjusting the volume thereof, it is soldered when mounted on the printed circuit board of the electronic device. Even if the electrolytic solution 17 expands in volume,
The increase in the internal pressure of the bottomed case 18 due to the expansion is reduced by the void portion 20 provided in the bottomed case 18, whereby the sealing body 19 is not swollen and deformed. The mounting of the lead type aluminum electrolytic capacitor by soldering on the printed circuit board can be performed in a stable state without tilting of the lead type aluminum electrolytic capacitor.

However, in each of the above-described embodiments of the present invention, the volume of the void portion 20 is 5% of the inner volume of the bottomed case 18.
If the temperature is less than 180 ° C., the internal pressure caused by the compression of the internal space of the bottomed case 18 due to the volume expansion of the electrolytic solution 17 is sufficient even if the soldering is performed at about 180 ° C. which is generally considered to be the lowest temperature. Cannot be reduced to
The sealing body 19 will be swollen and deformed, and as a result,
This may adversely affect the mounting of electronic equipment on the printed circuit board.

On the other hand, the volume of the void 20 is equal to the bottomed case 18
If it exceeds 40% of the inner volume of the capacitor, the size of the capacitor becomes too large, which is not preferable in practice.

In each of the above-described embodiments of the present invention, an example of various adjustment methods when the void portion 20 is provided in the bottomed case 18 has been described. It is needless to say that it is possible to provide the above method, and in these methods as well, similar to the first to fifth embodiments of the present invention, the soldering onto the printed circuit board of the electronic device can be performed in a stable state. .

That is, as the first method, the anode foil 1
It is also possible to provide the void portion 20 in the bottomed case 18 by adjusting the thickness of the cathode foil 14 and the separator 15 and winding them, and by adjusting the winding diameter of the capacitor element 11.

As a second method, by adjusting the widths of the anode foil 13, the cathode foil 14 and the separator 15 and winding them, and adjusting the length of the capacitor element 11, the void portion 20 is formed in the bottomed case 18. Can be provided.

As a third method, the capacitor element 11
By adjusting the width, the length, or the thickness of the unwinding tape 16, the space 20 is formed in the bottomed case 18.
Can be provided.

As a fourth method, the capacitor element 11
By adjusting the diameter of the core of the
It is possible to provide the void portion 20 therein.

As a fifth method, the capacitor element 11
The void portion 20 can be provided in the bottomed case 18 by adjusting the gap between the surface of the bottomed case 18 from which the lead member 12 is not pulled out and the inner bottom surface of the bottomed case 18.

As a sixth method, it is possible to form the void portion 20 in the bottomed case 18 by adjusting the density of the separator 15.

As a seventh method, the void 20 can be provided in the bottomed case 18 by adjusting the void volume in the pit of the etched portion of the anode foil 13 or the cathode foil 14.

[0026]

As described above, according to the lead-type aluminum electrolytic capacitor of the present invention, a void portion occupying 5% or more of this space is provided in the space surrounded by the bottomed case and the sealing body. Even if the electrolytic solution expands in volume when soldering when it is mounted on the printed circuit board of an electronic device, the increase in internal pressure of the bottomed case due to the expansion is provided in the space surrounded by the bottomed case and the sealing body. It is reduced by the voids, which prevents the sealing body from swelling and deforming.Therefore, when mounting the lead-type aluminum electrolytic capacitor by soldering on the printed circuit board of electronic equipment, the lead-type aluminum electrolytic capacitor can be mounted. Can be performed in a stable state without tilting, and it is possible to prevent adverse effects on the capacitor characteristics such as an increase in leakage current during soldering.

[Brief description of drawings]

FIG. 1 is a sectional view of a lead-type aluminum electrolytic capacitor showing an embodiment of the present invention.

FIG. 2 is a sectional view of a lead-type aluminum electrolytic capacitor showing another embodiment of the present invention.

FIG. 3 is a sectional view of a lead-type aluminum electrolytic capacitor showing still another embodiment of the present invention.

FIG. 4 is a sectional view of a lead-type aluminum electrolytic capacitor showing a conventional example.

[Explanation of symbols]

 11 Capacitor Element 12 Lead Member 13 Anode Foil 14 Cathode Foil 15 Separator 16 Winding Tape 17 Electrolyte Solution 18 Bottomed Case 19 Sealing Body 20 Void

Claims (2)

[Claims] 1. A capacitor element in which an anode foil and a cathode foil to which a lead member is connected are wound with a separator interposed therebetween and winding is stopped, an electrolytic solution impregnated in the capacitor element, and the capacitor element. A bottomed case for accommodating the bottomed case, and a sealing body that seals the opening of the bottomed case and leads the lead member through to the outside, and is a space surrounded by the bottomed case and the sealing body. A lead-type aluminum electrolytic capacitor with a void that occupies 5% or more of this space. 2. The lead-type aluminum electrolytic capacitor according to claim 1, wherein the volume of the void portion is 5 to 40% of the volume of the space surrounded by the bottomed case and the sealing body.