JP2006278849A - Ultrasonic welding horn and manufacturing method of electrolytic capacitor using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic welding horn capable of ensuring an sufficient bonding area, raising bonding strength, and preventing a withdrawal lead from peeling-off at the time of carrying out an ultrasonic joint of the withdrawal lead of an electrolytic capacitor and a terminal. <P>SOLUTION: In the ultrasonic welding horn, a lead pulled out of a capacitor element is tightened and jointed to a terminal provided at a sealing plate and the tip of the lead is turned up and placed on the tightened terminal, and the pulled-out lead and the tightened terminal are ultrasonic-welded. The ultrasonic welding horn is formed with a first protrusion of a dome shape having a curved portion and a flat portion at the tip thereof, and a second protrusion (polygonal cone shape, conical shape, elliptic cone shape) of an acuminate shape formed by enclosing the first protrusion. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic welding horn used for ultrasonic welding between a lead of an aluminum electrolytic capacitor and a terminal, and a method of manufacturing an electrolytic capacitor using the ultrasonic welding horn.

Conventional ultrasonic bonding between a lead lead and a crimped terminal is based on a plurality of projections having a large shape (cone-shaped projections) on the joining surface of an ultrasonic transducer (welding horn) (for example, , See Patent Document 1).
In some cases, the number of ultrasonic welds between the lead lead and the crimped terminal is reduced and the lead leads are welded to each other (for example, see Patent Document 2).
Furthermore, the ultrasonic welding horn has a shape including a columnar first protrusion having a sharp portion and a second protrusion lower than the first protrusion formed surrounding the first protrusion. There were some (see, for example, Patent Document 3).
Japanese Patent No. 2811732 (FIG. 4) JP 09-186051 (FIG. 1) JP 2004-79563 A

  As described in the above-mentioned Patent Document 1, when joining is performed with an ultrasonic vibrator having a large protrusion (FIG. 7), particularly when joining a plurality of lead-out leads, when the number of leads is large, FIG. As shown in (c), there is a problem in that the upper lead lead that is overlaid causes edge breakage and peeling occurs. This peeling of the joint causes an increase in connection resistance and a reduction in bonding strength, resulting in an electrolytic capacitor. The electrical performance of deteriorates.

  As an improvement measure, in Patent Document 2, in order not to cause pull-out lead peeling, a method of cutting a plurality of lead leads at a bonding portion with respect to the number of lead leads, reducing the number of overlaps, and joining with a small thickness Is taken (FIG. 8).

  Further, like the ultrasonic welding horn of Patent Document 3, the height of the columnar first protrusion having a sharp portion is made higher than the second protrusion formed so as to surround the first protrusion. Some are (FIGS. 9-12).

  However, when the first projecting part having a large shape is a sharp part, the joint area between the lead lead and the crimped terminal is often reduced and the joint strength is lowered, and the edge of the upper lead lead is broken. There was a problem that it was easy to do.

  Due to the above problems, the joint strength between the lead-out lead and the crimped terminal is large, even if the projecting part is a sharp part or a flat part. A structure that does not cause edge breakage has been demanded.

The present invention solves the above-described problem, and includes a dome-shaped first protrusion having a flat portion or a curved surface portion at a tip, and a sharp second protrusion formed so as to surround the first protrusion. An ultrasonic welding horn having a portion is to be applied.
That is, the lead drawn from the capacitor element is crimped and joined to the terminal attached to the sealing plate, the tip of the lead is folded and placed on the crimped terminal, and the lead and the crimped terminal are In ultrasonic welding horn for ultrasonic welding,
The ultrasonic welding horn includes a dome-shaped first protrusion having a flat portion or a curved surface portion at a tip, and a sharp second protrusion formed so as to surround the first protrusion. An ultrasonic welding horn characterized by the following.

  Further, in the ultrasonic welding horn, the shape of the second protrusion is a triangular pyramid shape, a quadrangular pyramid shape or a polygonal pyramid shape higher than that, or a conical shape or an elliptical pyramid shape.

  Further, the ultrasonic welding horn is characterized in that there is a single first protrusion and a plurality of second protrusions.

  And the height of a 1st protrusion is 0.2-1.0 mm higher than the height of a 2nd protrusion, It is an ultrasonic welding horn characterized by the above-mentioned.

  Further, the present invention is a method for manufacturing an electrolytic capacitor, wherein the lead lead and the terminal are welded using the ultrasonic welding horn.

By joining with a dome-shaped first protrusion having a flat or curved surface at the tip of the ultrasonic welding horn, a sufficient joining area between the lead and the terminal can be secured, and the joining strength can be improved. it can.
In the unlikely event that an edge break occurs in the upper lead, the upper lead and the lower lead are joined by the sharp second protrusion that surrounds the first protrusion. Therefore, bonding is maintained and peeling can be prevented.
Therefore, since the strength of the ultrasonic bonding portion is improved and the bonding can be maintained, the electrical performance of the electrolytic capacitor is stabilized and long-term reliability can be improved.

  As shown in FIG. 5, the shape of the ultrasonic welding horn used for joining the lead lead and the crimped terminal includes a dome-shaped first protrusion having a flat portion at the tip, and a first protrusion. The shape is provided with a quadrangular pyramid-shaped second protrusion formed so as to be surrounded.

  Embodiments of the present invention will be specifically described below with reference to the drawings.

[Examples 1 to 5] First protrusion: flat tip / dome, second protrusion: quadrangular pyramid, FIG.
The joining surface shape of the ultrasonic welding horn is provided with a dome-shaped first protrusion having a flat portion at the tip and a quadrangular pyramid-shaped second protrusion formed so as to surround the first protrusion. A composite shape was formed, and an ultrasonic bonding experiment was conducted to investigate whether or not peeling of the lead lead occurred.
At this time, the difference in height between the first protrusion and the second protrusion was 0.1 to 1.3 mm, and it was confirmed whether there was a difference in lead peeling.
The joining conditions between the lead and the terminal were as follows.
(1) Energy 150J, (2) Applied pressure 0.3 MPa, (3) Holding time 0.2 seconds The state joined as described above is shown in the perspective view of FIG. 3 and the cross-sectional view of FIG. 4A is a state during welding, FIG. 4B is a state after welding, and is a cross-sectional view taken along line AA ′ of FIG.
A sealing plate was attached to an electrolytic capacitor element rated for 400 V-10,000 μF (size: φ90 × 170 Lmm) by bonding the lead lead and the terminal.

[Example 6] First protrusion: hemispherical dome, second protrusion: hexagonal pyramid, FIG.
The shape of the joining surface of the ultrasonic welding horn is a composite shape having a hemispherical dome-shaped first protrusion and a hexagonal pyramid-shaped second protrusion formed so as to surround the first protrusion at the tip ( 6), ultrasonic bonding experiments were conducted, and peeling of the lead was investigated.
At this time, the difference in height between the first protrusion and the second protrusion was 0.7 mm.
Moreover, the joining conditions between the lead and the terminal were the same as those in Examples 1 to 5.
A sealing plate was attached to an electrolytic capacitor element rated for 400 V-10,000 μF (size: φ90 × 170 Lmm) by bonding the lead lead and the terminal.

(Conventional example 1) Four frustoconical protrusions, FIG.
The joining surface shape of the ultrasonic welding horn was formed with four frustoconical protrusions, an ultrasonic joining experiment was performed, and peeling of the lead was investigated.
Moreover, the joining conditions between the lead and the terminal were the same as those in Examples 1 to 5.
The state joined as described above is shown in the perspective view of FIG. 1 and the cross-sectional view of FIG. 2A is a state during welding, FIG. 2B is a cross-sectional view taken along line AA ′ of FIG. 1 when lead peeling does not occur, and FIG. 2C is a cross-sectional view when lead peeling occurs. .
A sealing plate was attached to an electrolytic capacitor element rated for 400 V-10,000 μF (size: φ90 × 170 Lmm) by bonding the lead lead and the terminal.

(Conventional example 2) First protrusion: square pyramid (columnar), second protrusion: square pyramid, FIGS.
The joining surface shape of the ultrasonic welding horn includes a columnar first protrusion having a quadrangular pyramid, and a quadrangular pyramid and prism-shaped second protrusion formed so as to surround the first protrusion. A composite shape was formed, and an ultrasonic bonding experiment was performed to investigate peeling of the lead.
At this time, the difference in height between the first protrusion and the second protrusion was 0.7 mm.
A sealing plate was attached to an electrolytic capacitor element rated for 400 V-10,000 μF (size: φ90 × 170 Lmm) by bonding the lead lead and the terminal.

  Table 1 shows the results of the number of pull-outs of the lead and the tensile strength test (lead batch, first lead) for Examples 1 to 6 and Conventional Examples 1 and 2. The number of samples was 20 each.

As is clear from Table 2, Examples 1 to 4 have no lead peeling, which is superior to Conventional Examples 1 and 2.
However, if the difference in height between the first protrusion and the second protrusion is 0.1 mm, the pushing by the first protrusion becomes shallow with respect to the lead, and the joint strength between the lead and the terminal decreases, and the lump The tensile strength decreases (Example 1), and at 1.3 mm, the indentation by the second protrusion becomes shallow, and lead peeling occurs (Example 5). Therefore, the difference in height between the first protrusion and the second protrusion is suitably in the range of 0.2 to 1.0 mm.
Further, no lead peeling occurred in Example 6 in which the first protrusion was formed in a hemispherical dome shape and the second protrusion was formed in a hexagonal pyramid shape.
On the other hand, the conventional example 1 in which the shape of the joint surface of the ultrasonic welding horn is four truncated cones, and the conventional example in which the first protrusion is a quadrangular pyramid (columnar) and the second protrusion is a quadrangular pyramid. In No. 2, there was a problem in the bonding strength, and peeling occurred on the superimposed lead-out leads (first and second sheets) on the terminal side.

  In the above embodiment, a quadrangular pyramid shape is used for the second protrusion, but other than this, a triangular pyramid shape, a polygonal pyramid shape greater than a pentagonal pyramid shape, a conical shape, and an elliptical cone shape may be used. The same effect can be obtained.

It is a state figure when a drawer lead is joined to a terminal of a sealing board with the conventional ultrasonic horn. 2A and 2B are cross-sectional views taken along the line A-A 'of FIG. 1. FIG. 2A is a state diagram during welding, FIG. 2B is a state diagram after welding, and FIG. FIG. 5 is a state diagram when a lead is joined to a terminal of a sealing plate by an ultrasonic horn according to an embodiment of the present invention. 4A and 4B are cross-sectional views taken along the line A-A 'of FIG. 3, where FIG. 4A is a state diagram during welding, and FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of the ultrasonic horn by the Example of this invention, (a) is a top view, (b) is a side view, (c) is a perspective view. It is a perspective view of the ultrasonic horn by other examples of the present invention. It is a perspective view of the ultrasonic horn by a prior art example. It is sectional drawing when a drawer lead is joined to a terminal of a sealing board by other conventional examples, (a) is before joining and (b) is a state figure after joining. It is a side view which shows the ultrasonic welding horn by another prior art example. It is a top view which shows the horn part of the ultrasonic welding horn of FIG. 10A and 10B show cross sections of the horn portion shown in FIG. 10, where FIG. 10A and 10B show cross sections of the horn portion shown in FIG. 10, where FIG. 10A is a cross-sectional view taken along line 4A-4A in FIG. 10, and FIG. 10B is a cross-sectional view taken along line 4B-4B in FIG.

Explanation of symbols

1 Sealing plate 2a Terminal (Ultrasonic welding surface side)
2b Terminal (sealing plate side, crimp joint)
3 Leads 3a, 3b Leads 4 Ultrasonic joint 4a Ultrasonic joint (by first protrusion)
4b Ultrasonic junction (by second protrusion)
5 Washer 6 Ultrasonic welding horn (prism)
7 1st protrusion (tip flat dome shape)
7a Flat part 8 2nd protrusion (quadrangular pyramid shape)
9 Ultrasonic welding horn (cylindrical)
10 First protrusion (hemispherical)
11 Second protrusion (hexagonal cone)
12 Ultrasonic welding horn (cylindrical, tapered)
13 Projection (conical shape)
14 Ultrasonic welding horn 15 Hole 16 Rivet 17 Elastic ring 18 Ultrasonic welding horn (square column, taper)
19 1st protrusion (quadrangular pyramid shape)
20a Second protrusion (quadrangular pyramid shape)
20a Second protrusion (prism shape)

Claims (5)

The lead drawn from the capacitor element is crimped and joined to the terminal attached to the sealing plate, and the tip of the lead is folded back and placed on the crimped terminal, and the lead and the crimped terminal are connected to each other. In ultrasonic welding horn for sonic welding,
The ultrasonic welding horn includes a dome-shaped first protrusion having a flat portion or a curved surface portion at a tip, and a sharp second protrusion formed so as to surround the first protrusion. Ultrasonic welding horn characterized by.   2. The ultrasonic welding horn according to claim 1, wherein the shape of the second protrusion is a triangular pyramid shape, a quadrangular pyramid shape, or a polygonal pyramid shape higher than that, or a conical shape or an elliptical cone shape.   2. The ultrasonic welding horn according to claim 1, wherein the number of the first protrusions is one and the number of the second protrusions is plural.   2. The ultrasonic welding horn according to claim 1, wherein the height of the first protrusion is 0.2 to 1.0 mm higher than the height of the second protrusion.   A method for producing an electrolytic capacitor, wherein the lead lead and the terminal are welded using the ultrasonic welding horn according to claim 1.

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