JP2002025871A - Chip-type aluminum electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of the conventional chip aluminum electrolytic capacitor that poor soldering resulting from detachment of leads due to the spring back phenomenon from bending parts of the leads, and to provide a high-reliability chip-type aluminum electrolytic capacitor, to which proper soldering can be performed. SOLUTION: The chip-type aluminum electrolytic capacitor is formed by sealing a metallic case 3, which houses a capacitor device 1a with a sealing member 4 and providing a base plate 5, which is provided with slots 5b for housing bent leads 2a and 2b led out from the sealing member 4 and is mounted on the side of the sealing member 4 and projection 5c as supports for bending of the leads 2a and 2b in the slots 5b of the base plate 5. In this way, detachment of the leads 2a and 2b due to the spring back phenomenon can be prevented, and satisfactory soldering can be made to obtain a high-reliability chip-type aluminum electrolytic capacitor.

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 as a surface mount type mounted on a substrate.

[0002]

2. Description of the Related Art FIGS. 3A and 3B are a front sectional view and a side sectional view showing the structure of a conventional chip type aluminum electrolytic capacitor of this type. In FIG. The chip-type aluminum electrolytic capacitor 10 is formed by winding an anode foil and a cathode foil (not shown) to which an anode lead 2a and a cathode lead 2b are connected, respectively, with a separator interposed therebetween. The capacitor element 1 a is housed in a bottomed cylindrical metal case 3 together with a driving electrolyte, and the open end of the metal case 3 is sealed with a sealing member 4.

Reference numeral 6 denotes an insulating seat plate mounted so as to contact the open end of the metal case 3. The seat plate 6 has a pair of lead wires 2a and 2b led out of the capacitor element 1a. And a groove 6b for accommodating a pair of lead wires 2a and 2b (bent portions are flattened) which are inserted through the hole 6a in a direction perpendicular to the outer surface (in the drawing). (Bottom surface) so that it can be surface-mounted on a substrate (not shown).

[0004]

However, in the chip type aluminum electrolytic capacitor 10 having the above-mentioned conventional structure, a pair of lead wires 2a, 2a inserted through the hole 6a of the insulating seat plate 6 is provided.
When b is bent along the groove 6b provided in the seat plate 6, since the bending fulcrum of the lead wires 2a and 2b is only one place in the circumferential portion of the hole 6a, the bending fulcrum has a shape close to an acute angle. For this reason, the lead wires 2a and 2b once bent and housed in the groove 6b of the seat plate 6 are in a state of trying to return to the original state due to the spring-back phenomenon of the bent portion, and as a result, the floating 7 as shown in FIG. This floating 7
Therefore, when the solder thickness is small, there is a problem that the soldering strength is reduced.

[0005] Further, as shown in FIG. 5, in the case where the dummy terminal 8 a is provided on the outer surface (bottom surface serving as a soldering surface) of the seat plate 8, such a problem is particularly noticeable, and the worst case is considered. In the case of the above, there is a risk that the solder will not contact the dummy terminal 8a.
There was a problem that it was necessary to take immediate measures.

As a means for solving such a problem, as shown in FIG. 6, a groove 9b provided in the seat plate 9 is tapered such that the depth of the groove 9b is increased from the hole 9a toward the peripheral edge of the seat plate 9. Attempts have been made to reduce the springback phenomenon by providing a lead. However, if the taper is too deep, a new problem arises in that the lead wires 2a and 2b remain submerged in the groove 9b and cannot be soldered. In fact, it was not a radical solution.

The present invention solves such a conventional problem,
It is an object of the present invention to provide a chip-type aluminum electrolytic capacitor capable of suppressing the occurrence of a springback phenomenon from a bent portion of a lead wire, eliminating the floating of the lead wire from a seat plate, and performing good soldering.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 of the present invention is particularly directed to a metal housing in which a capacitor element having a lead wire for external drawing is housed together with a driving electrolyte. A case, a sealing member provided with a hole through which the lead wire is inserted, and sealing the open end of the metal case, a hole through which a lead wire derived from the sealing member is inserted, and a lead wire inserted through the hole at a right angle. In a chip type aluminum electrolytic capacitor comprising an insulating seat plate provided with an outer surface provided with a groove portion to be folded and accommodated in a direction, the lead wire is bent into the groove portion provided in the seat plate. With this configuration, a projection serving as a fulcrum is provided. With this configuration, the lead wire can be bent with the fulcrum at the two locations of the periphery of the hole of the seat plate and the projection provided in the groove, so that the curved surface is formed. The occurrence of springback is extremely reduced due to bending, and the variation in bending position is reduced, so that the occurrence of floating of the lead wire can be greatly suppressed, and a high soldering strength can be stably obtained. The operation and effect that a highly reliable chip type aluminum electrolytic capacitor can be provided is obtained.

The invention described in claim 2 is particularly advantageous in claim 1.
In the invention described in the above, the protrusion serving as a bending fulcrum of the lead wire provided in the groove portion of the insulating seat plate is provided near the portion that intersects with the hole through which the lead wire is inserted. The operation and effect obtained by the first aspect of the invention can be obtained more efficiently.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the invention described in the present invention will be described using an embodiment of the present invention.

1A and 1B are a front sectional view and a bottom view showing the structure of a chip type aluminum electrolytic capacitor according to an embodiment of the present invention. FIG. 2 is a front sectional view and a bottom view of the same seat plate. FIG. In FIG. 1, reference numeral 1 denotes a chip type aluminum electrolytic capacitor. This chip type aluminum electrolytic capacitor 1 has an anode foil and a cathode foil (not shown) to which an anode lead 2a and a cathode lead 2b are connected, respectively, with a separator interposed therebetween. The capacitor element 1a formed by being wound and wound is housed together with the driving electrolyte in a bottomed cylindrical metal case 3 and the open end of the metal case 3 is sealed with a sealing member 4. Have been. The tip portions (bent portions to be described later) of the anode lead wire 2a and the cathode lead wire 2b are formed to be flat.

Reference numeral 5 denotes an insulating seat plate mounted so as to contact the open end of the metal case 3. The seat plate 5 has a pair of lead wires 2a and 2b led out from the capacitor element 1a. Are provided on the outer surface (the bottom surface in the figure) of a hole 5a through which the hole 5a is inserted and a pair of lead wires 2a and 2b inserted through the hole 5a are bent at right angles to accommodate the lead wire 2a. It is configured so that it can be surface-mounted on a substrate that does not. Reference numeral 5c denotes a protrusion serving as a bent branch provided in the groove 5b of the seat plate 5, and the protrusion 5c is provided near a portion intersecting the hole 5a provided in the seat plate 5. .

By forming the projection 5c serving as a bending fulcrum in the groove 5b of the seat plate 5 as described above, the pair of lead wires 2 of the chip type aluminum electrolytic capacitor 1 is provided.
When the lead wires 2a and 2b are bent along the grooves 5b formed in the seat plate 5, the lead wires 2a and 2b are inserted into the holes 5a formed in the seat plate 5.
And the projection 5c are bent at the bending fulcrum to be bent into a curved shape. Therefore,
The generation of springback is extremely reduced, and the variation in bending position is also reduced, so that the occurrence of floating of the lead wire can be greatly suppressed, and high soldering strength can be obtained stably. It is.

Reference numeral 5d denotes a chamfered portion provided at two corners which are both ends of one side in a direction intersecting with the groove 5b of the seat plate 5, and is provided on a side provided with such a chamfered portion 5d. If one of the anode and the cathode of a pair of lead wires is determined to be arranged, the anode and the cathode can be distinguished very easily from the appearance of the assembled chip type aluminum electrolytic capacitor 1. It is.

Table 1 shows the results of measuring the lead wire floating of the chip-type aluminum electrolytic capacitor 1 according to the present embodiment having the above-described configuration, together with the results of the conventional product as a comparative example.

[0016]

[Table 1]

As is clear from Table 1, the chip type aluminum electrolytic capacitor 1 according to the present embodiment is capable of suppressing the floating of the lead wires 2a and 2b to be small and obtaining good soldering strength. It can be seen from this result.

Further, the chip-type aluminum electrolytic capacitor 1 according to the present embodiment thus constructed is
As a result of confirming the state of occurrence of a soldering defect when soldering and mounting on a substrate at 00μ, it was found that there was no soldering out of 100 pieces.

In the above embodiment, the groove 5b of the insulating seat plate 5 is provided with only one protrusion 5c serving as a fulcrum of bending, but the present invention is not limited to this. Instead, a plurality of protrusions 5c may be provided.

[0020]

As described above, according to the present invention, the metal case accommodating the capacitor element is sealed with the sealing member, and the sealing member is provided with the groove for bending and housing the lead wire led out from the sealing member. The seat has a seat plate attached to the side, and the seat plate is provided with a projection serving as a fulcrum for bending the lead wire. Since it is bent with the fulcrum as a fulcrum, it is bent into a curved surface shape and the occurrence of springback is extremely reduced, and the variation in bending position is reduced, so that the occurrence of floating of the lead wire can be greatly suppressed, and it is high. This has the effect of stably obtaining a highly reliable chip-type aluminum electrolytic capacitor having a stable soldering strength.

[Brief description of the drawings]

FIG. 1A is a front sectional view showing a configuration of a chip-type aluminum electrolytic capacitor according to an embodiment of the present invention. FIG.

FIG. 2A is a front sectional view showing the seat plate. FIG. 2B is a bottom view of the seat plate.

FIG. 3A is a front sectional view showing a configuration of a conventional chip-type aluminum electrolytic capacitor. FIG.

FIG. 4 is a cross-sectional view of a main part of a conventional chip type aluminum electrolytic capacitor showing lead wire floating.

FIG. 5 is a bottom view showing a conventional chip-type aluminum electrolytic capacitor provided with dummy terminals.

FIG. 6 is a cross-sectional view of a main part showing a seat plate of a conventional chip-type aluminum electrolytic capacitor in which a countermeasure against lead floating is performed.

[Description of Signs] 1 Chip type aluminum electrolytic capacitor 1a Capacitor element 2a Anode lead wire 2b Cathode lead wire 3 Metal case 4 Sealing member 5 Insulating seat plate 5a Hole 5b Groove 5c Projection 5d Chamfered portion

Claims (2)

[Claims] 1. A capacitor element formed by winding an anode foil and a cathode foil to which an anode lead wire and a cathode lead wire for external drawing are respectively connected with a separator interposed therebetween, and a capacitor element formed by winding the anode foil and the cathode foil. And a bottomed cylindrical metal case containing a driving electrolyte, a sealing member having a hole through which the pair of lead wires are inserted, and sealing an open end of the metal case, and being derived from the sealing member. A chip comprising a hole through which a pair of lead wires are inserted and a groove for accommodating the lead wire inserted through the hole by bending at a right angle on the outer surface, the insulating seat plate being mounted so as to be in contact with the sealing member. A chip type aluminum electrolytic capacitor in which a protrusion serving as a fulcrum for bending a lead wire is provided in a groove provided in the insulating seat plate. 2. The chip-type aluminum electrolytic capacitor according to claim 1, wherein a protrusion serving as a bending fulcrum of the lead wire provided in the groove of the insulating seat plate is provided near a portion intersecting the hole through which the lead wire is inserted. .