JP3368716B2 - Chip type 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 chip type aluminum electrolytic capacitor used in various electronic devices.

[0002]

2. Description of the Related Art With the recent miniaturization, thinning, and multi-functionalization of electronic equipment, electronic circuits have been required to have a higher density, and electronic parts are rapidly becoming smaller, lower in height, and surface-mounted. There is.

A conventional chip-type aluminum electrolytic capacitor is as shown in Japanese Patent Laid-Open No. 59-212114, that is, as shown in FIGS. 3 and 4, an electrolytic solution is applied to a capacitor element 2 from which a lead member 1 is drawn out. 3, the capacitor element 2 is housed in the bottomed case 4, and the opening 5 of the bottomed case 4 is fitted with the sealing body 5 penetrating the lead member 1. Tighten the opening together with the sealing body 5, and curl 6 at the opening end of the bottomed case 4.
Then, the open end of the bottomed case 4 is pressed against the sealing body 5 to hold it, thereby performing sealing, and further, the lead member 1
Is penetrated through the insulating plate 7 arranged so as to abut the end face of the opening of the bottomed case 4, and the tip of the lead member 1 is bent to be housed in the recess 7 a provided on the outer surface of the insulating plate 7. I was trying to do it.

[0004]

Generally, in the chip type aluminum electrolytic capacitors shown in FIGS. 3 and 4, the chip type aluminum electrolytic capacitor is 200 ° C. at the time of reflow soldering when mounted on a printed circuit board of an electronic device. From 2
Since it is exposed to a high temperature of 40 ° C., the electrolytic solution 3 expands in volume, and due to this volume expansion, the bottomed case 4
The internal space of is compressed to increase the internal pressure,
When the strength of the sealing portion is insufficient, the sealing body 5 is swollen and deformed due to the increase in the internal pressure. In order to prevent this, in the chip-type aluminum electrolytic capacitors shown in FIGS. 3 and 4, the open end of the bottomed case 4 is curled to press the open end of the bottomed case 4 against the sealing body 5. The sealing strength is obtained by holding down. In such a structure,
The internal pressure generated in the bottomed case 4 at the time of reflow soldering works as a force to press and bend the sealing body 5 from the inside so as to expand the sealing body 5 toward the outside. Since the fulcrum when pushing and bending from the inside is the tip of the curl 6 at the opening end of the bottomed case 4, in order to prevent the sealing body 5 from expanding due to the internal pressure generated in the bottomed case 4, the bottomed case Diameter of the circle formed by the tip of the curl 6 at the opening of 4 (hereinafter referred to as curl diameter 8)
Is to be as small as possible.

However, in the chip type aluminum electrolytic capacitors shown in FIGS. 3 and 4, the curl 6 applied to the opening of the bottomed case 4 is formed by bending the bottomed case 4 in the direction of the inner diameter. Therefore, a variation of double the total length of the bottomed case 4 is reflected in the curl diameter 8, and when the sealing device is composed of a curl roller with multiple heads, Since the positioning variation of the curl roller is added to the variation of the curl diameter 8 due to the variation of the total length of the bottomed case 4,
As a result, the curl diameter 8 of the opening of the bottomed case 4 had to be largely varied. For this reason, the curl diameter 8 of the opening of the bottomed case 4 varies greatly, and it is actually difficult to prevent the sealing body 5 from stably bulging and deforming during reflow soldering. The bulging deformation of the sealing body 5 presses the insulating plate 7 to cause the insulating plate 7 to warp, and the warping causes the surface mounting surface of the outer surface of the insulating plate 7 to be bent. When mounting a chip type aluminum electrolytic capacitor by reflow soldering, there is a problem that the chip type aluminum electrolytic capacitor is mounted in an inclined state.

The present invention solves the above-mentioned problems of the prior art by mounting an electronic device by soldering on a printed circuit board without tilting the chip-type aluminum electrolytic capacitor.
It is an object of the present invention to provide a chip type aluminum electrolytic capacitor which can be stably operated.

[0007]

In order to achieve the above object, a chip type aluminum electrolytic capacitor of the present invention comprises a capacitor element from which a lead member is drawn out, an electrolytic solution impregnated in the capacitor element, and the capacitor element. With a bottomed aluminum case, a sealing body for sealing the opening of the bottomed aluminum case, and a lead member disposed on the outer surface so as to abut the end surface of the opening of the bottomed aluminum case. The lead member is housed in a bottomed aluminum case by impregnating the capacitor element from which the lead member is drawn out with an electrolytic solution, and the lead member is provided in the opening of the bottomed aluminum case. Attach the sealing body that penetrates the sealing body, arrange the aluminum reinforcing member so that it abuts the sealing body from the outside of the sealing body, and further cover the open end of the bottomed aluminum case. And the open end of the bottomed aluminum case is pressed against the aluminum reinforcing member to hold it down, and at the same time, the lead member is passed through the insulating plate, and the tip of the lead member is placed outside the insulating plate. It is configured to be bent along the surface.

[0008]

According to the chip type aluminum electrolytic capacitor having the above structure, the capacitor element with the lead member pulled out is impregnated with the electrolytic solution to house the capacitor element in the bottomed aluminum case, and the opening of the bottomed aluminum case is provided. Attach the sealing body that penetrates the lead member to the above, and arrange the aluminum reinforcing member so as to come into contact with the sealing body from the outside of the sealing body. Since the sealing is performed by pressing the open end of the aluminum case against the aluminum reinforcing member, the aluminum reinforcing member in contact with the sealing body obtains the sealing strength of the sealing body instead of the curl. As a result, the curl and its tip simply transmit the force to hold the sealing body to the aluminum reinforcing member. However, the internal pressure generated during reflow soldering does not work as a fulcrum when the sealing body is pressed and bent from the inside to inflate the sealing body toward the outside. The problem of swollen deformation of the sealing body at the time of reflow soldering, which has been caused by the variation in the curl diameter due to the variation in the positioning of the curl roller, can be solved. In this way, the aluminum reinforcing member arranged so as to contact the sealing body from the outside of the sealing body firmly suppresses the sealing body, so that the sealing body does not swell and deform, and the opening end surface of the bottomed aluminum case is closed. The insulating plate with the lead member facing the outer surface will not be warped due to pressure when it is arranged so as to abut on the chip. The aluminum electrolytic capacitor can be operated in a stable state without tilting.

[0009]

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 chip-type aluminum electrolytic capacitor according to an embodiment of the present invention. In FIG. 1, 11 is a capacitor element.
1 is constituted by winding an anode foil and a cathode foil with a separator interposed therebetween, and pulling out a lead member 12 from the capacitor element 11 and impregnating the capacitor element 11 with an electrolytic solution 13. It is housed in a bottomed aluminum case 14 formed in a bottomed cylindrical shape, and a sealing body 15 penetrating the lead member 12 is attached to the opening of the bottomed aluminum case 14, and this sealing body 15 The aluminum reinforcing member 16 penetrating the lead member 12 is arranged so as to come into contact with the sealing body 15 from the outside, and a curl 17 is applied to the opening end of the bottomed aluminum case 14 so that the bottomed aluminum case 14 has Sealing is performed by pressing the open end against the aluminum reinforcing member 16 and holding it down. Reference numeral 18 denotes an insulating plate arranged so as to abut the end face of the opening of the bottomed aluminum case 14. The lead member 12 also penetrates the insulating plate 18, and the leading end of the lead member 12 is bent. It is housed in a recess 18 a provided on the outer surface of the insulating plate 18.

The aluminum reinforcing member 16 is shown in FIG.
As shown in FIG. 2 (a), the lead member 12 is formed by a disk provided with a through hole 16a or a ring-shaped disk as shown in FIG. 2 (b) to obtain mechanical strength and lead member. Twelve anodes and cathodes are devised so as not to short-circuit.

Table 1 shows, as the material of the aluminum reinforcing member 16, pure aluminum (JIS name: A1050),
Aluminum / manganese alloy (JIS name: A300
4), aluminum / magnesium alloy (JIS name: A
5052) is used for comparison with Examples 1 to 3 of the present invention and a conventional example in which the aluminum reinforcing member 16 is not arranged in order to clarify the effect of the present invention.

Although not specifically shown in the above-mentioned embodiments of the present invention, as the material of the aluminum reinforcing member 16, an aluminum alloy may be used other than those shown in the first to third embodiments of the present invention. It's good.

In order to resist the force of the internal pressure generated in the bottomed aluminum case 14 during soldering, which pushes the sealing body 15 from the inside to inflate the sealing body 15 toward the outside, the aluminum reinforcing member 16 is provided. The heat deformation temperature is set to be equal to or higher than the temperature to which the chip type aluminum electrolytic capacitor is exposed during soldering, and the bending strength of the aluminum reinforcing member 16 at the temperature to which the chip type aluminum electrolytic capacitor is exposed during soldering is the bottomed aluminum case 14 during soldering.
It is necessary to make it stronger than the internal pressure generated inside,
In the current chip type aluminum electrolytic capacitor, the temperature to which the chip type aluminum electrolytic capacitor is exposed at the time of soldering is as high as about 260 ° C., or in order to withstand the internal pressure generated in the bottomed aluminum case 14 at the time of soldering. The required bending strength is about 10 kg / mm ² , and in this case, the above-mentioned material of the aluminum reinforcing member 16 has characteristics that sufficiently satisfy the above-mentioned heat deformation temperature and bending strength due to its material characteristics. There is something. The aluminum reinforcing member 16 employs aluminum as a material. Since this aluminum usually has a corrosion-resistant oxide film formed on its surface, it is extremely excellent in corrosion resistance. In the environment where the capacitor is used, the corrosiveness of the aluminum reinforcing member 16 itself does not pose any problem as in the bottomed aluminum case 14, and can sufficiently fulfill the reinforcing function of the sealing body 15 described above. Furthermore, aluminum reinforcing member 1
Since 6 and the bottomed aluminum case 14 are of the same type of material, the contact between the aluminum reinforcing member 16 and the curl of the bottomed aluminum case 14 due to the sealing does not cause a contact potential difference between them, and, for example, it occurs. Even if it is extremely small, there is no problem with corrosion at this point.

Further, (Table 1) shows the chip-type aluminum electrolytic capacitors according to the first, second and third embodiments of the present invention,
50v of the chip type aluminum electrolytic capacitor in the conventional example
1000 pieces each with a rating of 10 μF are manufactured, and the temperature is 23
The results of a reflow soldering test at 0 ° C are also shown.

[0015]

[Table 1]

As is clear from this (Table 1), according to the chip-type aluminum electrolytic capacitors of Examples 1, 2, and 3 of the present invention, the aluminum reinforcing member 16 is disposed so as to abut the sealing body 15, Since the aluminum reinforcing member 16 directly suppresses the sealing body 15 firmly, it is called a bulging deformation of the sealing body 15 at the time of reflow soldering which is caused by the variation of the curl diameter 8 as in the conventional chip type aluminum electrolytic capacitor. The problem goes away,
In this way, the sealing body 15 does not swell and deform during reflow soldering, and the insulating plate 18 arranged so as to abut the end face of the opening of the bottomed aluminum case 14 receives pressure and warps. Therefore, the electronic device can be mounted on a printed circuit board by soldering in a stable state without tilting the chip-type aluminum electrolytic capacitor.

In addition, in the aluminum reinforcing member 16 constituted by the disc provided with the through hole 16a of the lead member 12 shown in FIG. 2A or the ring-shaped disc shown in FIG. The aluminum reinforcing member 16 shown in FIG. 2 has an advantage that a relatively large sealing strength can be obtained because the entire outer surface of the sealing body 15 is suppressed.
The aluminum reinforcing member 16 shown in (b) is the lead member 1.
Since it is not necessary to mount the 2 through the through-hole 16a of the aluminum reinforcing member 16 through an operation such as positioning and passing it through, it has an advantage of being relatively easy to manufacture.

[0018]

As described above, according to the chip type aluminum electrolytic capacitor of the present invention, the capacitor element from which the lead member is drawn out is impregnated with the electrolytic solution to house the capacitor element in the bottomed aluminum case and the bottomed aluminum electrolytic capacitor. A sealing body having the lead member penetrating through it is attached to the opening of the case, an aluminum reinforcing member is arranged so as to come into contact with the sealing body from the outside of the sealing body, and a curl is provided at the opening end of the bottomed aluminum case. Since the sealing is performed by pressing and holding the open end of the bottomed aluminum case against the aluminum reinforcing member, the aluminum reinforcing member abutting on the sealing member is replaced by the sealing member instead of the curl. It acts directly to obtain the sealing strength, and as a result, the curl and its tip simply transmit the force to hold the sealing body to the aluminum reinforcing member. However, since the internal pressure generated during reflow soldering does not work as a fulcrum when the sealing body is bent from the inside to inflate the sealing body toward the outside, the length of the bottomed case or the sealing The problem of swollen deformation of the sealing body at the time of reflow soldering, which has been caused by variations in the curl diameter due to variations in the positioning of the curl roller at the time, can be solved. In this way, the reinforcing member arranged so as to contact the sealing body from the outside of the sealing body firmly suppresses the sealing body, so that the sealing body does not swell and deform, and the end face of the opening of the bottomed aluminum case is not deformed. Since the insulating plate, which is arranged so as to abut and the lead member faces the outer surface, is not pressed and warped, mounting by electronic soldering on the printed circuit board of a chip type aluminum The electrolytic capacitor can be operated in a stable state without tilting.

[Brief description of drawings]

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

FIG. 2A is a plan view of a plastic reinforcing member in the same chip-type aluminum electrolytic capacitor, and FIG. 2B is a plan view showing another example of the plastic reinforcing member.

FIG. 3 is a vertical sectional view of a chip-type aluminum electrolytic capacitor showing a conventional example.

[Fig. 4] Bottom view of the aluminum electrolytic capacitor

[Explanation of symbols] 11 Capacitor element 12 Lead member 13 Electrolyte 14 bottomed aluminum case 15 Sealed body 16 Aluminum reinforcement member 16a through hole 17 curls 18 Insulation plate

Front page continuation (72) Inventor Katsuya Fujimoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takashi Iwakiri 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56 ) Reference JP-A-60-144930 (JP, A) Actual development 62-78738 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01G 9/10 H01G 9/008

Claims (2)

(57) [Claims] 1. A capacitor element from which a lead member is drawn out, an electrolytic solution impregnated in the capacitor element, a bottomed aluminum case for accommodating the capacitor element, and a sealing for sealing the opening of the bottomed aluminum case. The body and the bottomed aluminum case are arranged so as to contact the end face of the opening,
And an insulating plate with the lead member facing the outer surface, the capacitor element from which the lead member is drawn out is impregnated with an electrolytic solution, and the capacitor element is housed in a bottomed aluminum case. A sealing body having the lead member penetrating through it is attached to the opening of the case, an aluminum reinforcing member is arranged so as to come into contact with the sealing body from the outside of the sealing body, and a curl is provided at the opening end of the bottomed aluminum case. By applying and pressing the open end of the bottomed aluminum case against the aluminum reinforcing member for sealing, the lead member is penetrated into the insulating plate, and the tip of the lead member is attached to the outer surface of the insulating plate. A chip-type aluminum electrolytic capacitor configured to bend along the line. 2. The chip-type aluminum electrolytic capacitor according to claim 1, wherein the aluminum reinforcing member is a disk provided with a through hole for the lead member or a ring-shaped disk.