JPH08293431A - Chip type aluminum electrolytic capacitor - Google Patents

Abstract

PURPOSE: To provide a chip type aluminum electrolytic capacitor which can be mounted by soldering on the printed board of an electronic apparatus in a stable state without having the capacitor being inclined. CONSTITUTION: A capacitor element 11 with lead members 12 drawn out therefrom whereinto an electrolyte 13 is impregnated is stored in a bottomed case 14, and a sealant 15 with the lead members 12 penetrating therethrough is mounted in the opening of the bottomed case 14 while a reinforcing member 16 is so provided as to be contacted with the sealant 15 from its outside, and further, the end of the opening portion of the bottomed case 14 wherein a curl 17 is provided is pressed in contact with the reinforcing member 16, and thereby, the bottomed case 14 is sealed.

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 are inevitably 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 disclosed in Japanese Patent Application Laid-Open No. 59-212114.
That is, as shown in FIGS. 2 and 3, the capacitor element 2 from which the lead member 1 is pulled out is impregnated with the electrolytic solution 3 to house the capacitor element 2 in the bottomed case 4, and the opening of the bottomed case 4 A sealing body 5 penetrating the lead member 1 is attached to the portion, and the opening of the bottomed case 4 is tightened together with the sealing body 5, and a curl 6 is applied to the opening end of the bottomed case 4. The bottom case 4 is sealed by pressing the opening end of the bottom case 4 against the sealing body 5, and further the lead member 1 is passed through an insulating plate 7 arranged so as to abut the end face of the opening of the bottomed case 4. In addition, the tip portion of the lead member 1 is bent and stored in the concave portion 7a provided on the outer surface of the insulating plate 7.

[0004]

Generally, in the chip type aluminum electrolytic capacitors shown in FIGS. 2 and 3, the chip type aluminum electrolytic capacitor is 200 ° C. at the time of reflow soldering when mounting 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. 2 and 3, 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 that pushes and bends the sealing body 5 from the inside to expand the sealing body 5 toward the outside. 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. Therefore, in order to prevent the sealing body 5 from expanding due to the internal pressure generated in the bottomed case 4, 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. 2 and 3, 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. Since the curl diameter 8 reflects a variation that is twice the variation in the total length of the bottomed case 4, and if 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. Then, 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 bend, so 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. A bottomed case that accommodates the bottomed case, a sealing body that seals the opening of the bottomed case, and a lead member that is disposed so as to abut the end surface of the opening of the bottomed case and that faces the outer surface. A sealing element having an insulating plate, housing the capacitor element in a bottomed case by impregnating the capacitor element from which the lead member is drawn out with an electrolytic solution, and penetrating the lead member through the opening of the bottomed case. The body is attached, the reinforcing member is arranged so as to contact the sealing body from the outside of the sealing body, and the opening end of the bottomed case is curled to press the opening end of the bottomed case against the reinforcing member. Performs sealing by suppressing Te, the passed through the lead member to the insulating plate, and the front end portion of the lead member is obtained by adapted to bent and along the outer surface of the insulating plate.

[0008]

According to the chip type aluminum electrolytic capacitor having the above structure, the capacitor element from which the lead member is pulled out is impregnated with the electrolytic solution to house the capacitor element in the bottomed case, and the opening is formed in the opening of the bottomed case. Attach the sealing body that penetrates the lead member, arrange the reinforcing member so as to contact the sealing body from the outside of the sealing body, and further curl the opening end of the bottomed case to open the end of the bottomed case. Since the sealing member is configured to be pressed by pressing against the reinforcing member, the reinforcing member in contact with the sealing member has a direct function to obtain the sealing strength of the sealing member instead of the curl. As a result, the curl and its tip merely serve to transmit the force to hold the sealing body to the reinforcing member, and the internal pressure generated during the reflow soldering causes the sealing body to come from inside. Since it does not work as a fulcrum when bending and expanding the sealing body toward the outside, reflow soldering caused by variation in curl diameter due to variations in the length of the bottomed case or curling roller positioning during sealing. The problem of bulging deformation of the sealing body at the time of attachment is solved. In this way, the reinforcing member, which is 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 case is not touched. Since the insulating plate that is placed in contact with the lead member facing the outer surface will not be warped due to pressure, it is possible to mount it on the printed circuit board of electronic equipment by soldering on a chip type aluminum electrolytic The 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 case 14 made of aluminum having a bottomed cylindrical shape, and a sealing body 15 penetrating the lead member 12 is attached to the opening of the bottomed case 14, and the outside of the sealing body 15. The reinforcing member 16 penetrating the lead member 12 is arranged so as to contact the sealing member 15 from the above, and the opening end of the bottomed case 14 is curled to further reinforce the opening end of the bottomed case 14. It is sealed by pressing against 16 and holding down. 18 is a bottomed case 1
An insulating plate arranged so as to abut the end face of the opening of 4,
The lead member 12 also penetrates the insulating plate 18, and the leading end of the lead member 12 is bent and accommodated in a recess 18 a provided on the outer surface of the insulating plate 18.

As shown in Examples 1 to 3 of the present invention (Table 1), the reinforcing member 16 has a heat deformation temperature which is a temperature to which the chip type aluminum electrolytic capacitor is exposed during soldering, that is, 230 ° C. or higher, In addition, the bending strength at the temperature to which the chip type aluminum electrolytic capacitor is exposed during soldering is 10 kg / mm ² , 15 kg / mm ² , 20 kg /
It is defined as mm ² .

Further, in order to clarify the effect of the present invention, Table 1 shows the same structure as that of the embodiment of the present invention shown in FIG. Comparative Example 1 in which the temperature was less than the temperature to which the electrolytic capacitor was exposed, Comparative Example 2 in which the bending strength of the reinforcing member 16 at the temperature to which the chip-type aluminum electrolytic capacitor was exposed during soldering was lower than that of the example of the present invention, and Reinforcing member 16 A conventional example in which is not shown is shown for comparison.

Further, in this (Table 1), the chip-type aluminum electrolytic capacitors in Examples 1 and 2 of the present invention, the chip-type aluminum electrolytic capacitors in Comparative Examples 1 and 2 and the chip-type aluminum electrolytic capacitors in the conventional examples are shown. Shows the result of a reflow soldering test conducted at a temperature of 230 ° C., each of which is manufactured with a rating of 50 v10 μF.

[0013]

[Table 1]

As is clear from this (Table 1), according to the chip-type aluminum electrolytic capacitors of Examples 1 and 2 of the present invention, the reinforcing member 16 is arranged so as to abut the sealing body 15, and the reinforcing member 16 is arranged. Since the sealing body 15 is firmly suppressed by 16 directly, the problem of the swollen deformation of the sealing body at the time of reflow soldering, which is caused by the variation of the curl diameter like the conventional chip type aluminum electrolytic capacitor, is eliminated. In this way, the sealing body 15 does not bulge and deform during reflow soldering, and the insulating plate 18 arranged so as to abut the end face of the opening of the bottomed case 14 may be pressed and warped. Since it does not exist, mounting by soldering on the printed circuit board of electronic equipment,
The chip type aluminum electrolytic capacitor can be operated in a stable state without tilting.

However, even if the reinforcing member 16 is arranged as in the configuration of one embodiment of the present invention, as shown in Comparative Examples 1 and 2 of (Table 1), the thermal deformation temperature of the reinforcing member 16 is soldered. Sometimes the bending strength of the reinforcing member 16 is less than the temperature to which the chip type aluminum electrolytic capacitor is exposed, or at the temperature to which the chip type aluminum electrolytic capacitor is exposed during soldering.
If it is less than 0 kg / cm ² , the sealing strength of the sealing body 15 will be lost by the internal pressure of the bottomed case 14 that rises during soldering, and the sealing body 15 will swell and deform, and the swelling deformation will compress the insulating plate 18. Therefore, warpage occurs, which may bend the surface mounting surface of the outer surface of the insulating plate 18 and adversely affect the mounting on the printed board, which is not preferable in practice.

[0016]

As described above, in the chip type aluminum electrolytic capacitor of the present invention, the capacitor element from which the lead member is pulled out is impregnated with the electrolytic solution to house the capacitor element in the bottomed case, and A sealing body having the lead member penetrating through the opening is mounted, a reinforcing member is arranged so as to abut the sealing body from the outside of the sealing body, and the open end of the bottomed case is curled to form a bottomed case. Since the sealing is performed by pressing the open end of the case against the reinforcing member, the reinforcing member that is in contact with the sealing member is directly used to obtain the sealing strength of the sealing member instead of the curl. As a result, the curl and its tip merely serve to transmit the force to hold the sealing body to the reinforcing member, and the internal pressure generated during reflow soldering is applied to the sealing body. It does not work as a fulcrum when the inner body is bent and inflated to the outer side, so it was caused by variations in curl diameter due to variations in the length of the bottomed case or curl roller positioning during sealing. The problem of swollen deformation of the sealing body during reflow soldering is solved. In this way, the reinforcing member, which is 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 case is not touched. Since the insulating plate arranged so as to contact with each other and the lead member facing the outer surface is not pressed and warped,
It is possible to mount an electronic device by soldering on a printed circuit board in a stable state without tilting the chip-type aluminum electrolytic capacitor.

[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. 2 is a vertical sectional view of a conventional chip-type aluminum electrolytic capacitor.

[Fig. 3] Bottom view of the aluminum electrolytic capacitor

[Explanation of symbols]

 11 Capacitor Element 12 Lead Member 13 Electrolyte Solution 14 Bottom Case 15 Sealing Body 16 Reinforcing Member 17 Curl 18 Insulating Plate

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takashi Iwakiri 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masao Ukita, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Within

Claims (3)

[Claims] 1. A capacitor element from which a lead member is drawn out, an electrolytic solution impregnated in the capacitor element, a bottomed case for accommodating the capacitor element, and a sealing body for sealing the opening of the bottomed case. An insulating plate disposed so as to abut the end face of the opening of the bottomed case and having the lead member facing the outer surface, and the capacitor element from which the lead member is pulled out is impregnated with an electrolytic solution. Then, the capacitor element is housed in the bottomed case, and a sealing body having the lead member penetrating the opening of the bottomed case is attached.
A reinforcing member is arranged so as to come into contact with the sealing body from the outside of the sealing body, and the opening end portion of the bottomed case is curled to press and hold the opening end of the bottomed case against the reinforcing member for sealing. And the lead member penetrates the insulating plate, and the tip end of the lead member is bent along the outer surface of the insulating plate. 2. The chip-type aluminum electrolytic capacitor according to claim 1, wherein the thermal deformation temperature of the reinforcing member is set to a temperature above which the chip-type aluminum electrolytic capacitor is exposed during soldering. 3. The bending strength of the reinforcing member at the temperature to which the chip type aluminum electrolytic capacitor is exposed during soldering is 1
The chip-type aluminum electrolytic capacitor according to claim 1, wherein the amount is 0 kg / mm ² or more.