JP4310621B2 - Electrolytic capacitor manufacturing method and apparatus, and electrolytic capacitor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is a connection method by ultrasonic welding between the lead wire of an electrolytic capacitor such as an aluminum electrolytic capacitor and an electrode foil, and an ultrasonic welding apparatus provided with an ultrasonic welding horn and an anvil used for ultrasonic welding, The present invention relates to an electrolytic capacitor using this ultrasonic welding apparatus.
[0002]
[Prior art]
In an aluminum electrolytic capacitor, stitching, cold welding, ultrasonic welding, and the like have been conventionally used as a method for connecting an electrode foil and a lead wire serving as a lead terminal. In a small aluminum electrolytic capacitor, since the electrode foil and the lead wire are small, for example, the electrode foil has a small width of about 2 mm, the lead wire has a width of about 1 mm and a length of about 2 mm. Ultrasonic welding is used for such a small one.
[0003]
In such a small electrolytic capacitor, in order to connect the lead wire and the electrode foil by ultrasonic welding, the lead wire to be welded on the anvil and the electrode foil are placed on top of each other and ultrasonic waves are applied to the welded portion. The welding horn is pushed down to hold the lead wire and electrode foil between the anvil and the ultrasonic welding horn. In this state, the ultrasonic welding horn applies ultrasonic energy to the welded portion of the lead wire and the electrode foil to establish a connection. Has been made.
[0004]
As shown in FIG. 4 (a), the ultrasonic welding horn 1 has a plurality of protrusions 5, and as shown in FIG. 4 (b), the anvil 2 also has a plurality of irregularities 16, The lead wire and electrode foil are prevented from shifting when ultrasonic welding is performed. For example, Japanese Patent Laid-Open No. 60-91620 discloses a technique for joining such a lead wire and an electrode foil using ultrasonic welding.
[0005]
[Patent Document 1]
JP 60-91620 A [0006]
[Problems to be solved by the invention]
However, in such a small aluminum electrolytic capacitor, since the electrode foil and the lead wire are also small, especially when the lead wire is small, the width is 2 mm and the length is 1 mm, and the ultrasonic welding horn 1 has a plurality of welding protrusions. When the portion 5 is provided, the size of the projection itself is extremely small, so that the mechanical strength is low and it is very difficult to control the ultrasonic energy during welding. In addition, although a plurality of irregularities 16 are provided on one surface of the anvil 2 to prevent slipping, there is an effect of preventing slipping of the lead wire that comes into contact with the anvil 2, but slipping between the electrode foil and the lead wire is effective. The lead wire and the electrode foil may be misaligned and welded at the time of welding.
[0007]
Therefore, the present invention improves the workability of ultrasonic welding between the lead wire and the electrode foil in a small aluminum electrolytic capacitor, and also increases the bonding strength and improves the connection reliability and the manufacturing method of the electrolytic capacitor An object is to provide an apparatus and an electrolytic capacitor.
[0008]
[Means for Solving the Problems]
The manufacturing method of the electrolytic capacitor of the present invention that solved the problem, the ultrasonic welding apparatus for the electrolytic capacitor, and the structure of the electrolytic capacitor are as follows.
[0009]
The method for producing an electrolytic capacitor of the present invention is a method for producing an electrolytic capacitor in which a lead wire and an electrode foil are overlapped and welded by applying ultrasonic energy, the process of superimposing the lead wire and the electrode foil, It includes a process of pressing the side surface part and a process of applying ultrasonic energy while applying pressure to the overlapping part of the lead wire and the electrode foil and welding.
[0010]
That is, when performing the ultrasonic welding connection, by pressing the side surface portion of the lead wire, the side surface portion of the lead wire is pressed against the electrode foil side, and the lead wire and the electrode foil are fixed. The thickness of the lead wire is thin, and therefore the sharp side surfaces can be easily warped, and the lead wire and the electrode foil must be securely fixed in the lead wire of a small electrolytic capacitor with a very limited welding range. When applying ultrasonic energy in the next process, the deviation between the lead wire and the electrode foil is surely prevented, and after welding, the electrode foil is formed on the side surface of the lead wire. Since the lead wire and the electrode foil are fixed by pressing, the mechanical strength is improved and the reliability of ultrasonic welding is improved. In addition, since the side part of the lead wire has an acute angle, the lead wire and the electrode foil can be more securely fixed by pressing and lightly biting into the electrode foil.
[0011]
Moreover, at least a corner | angular part is pressed among the side parts of the said lead wire, It is characterized by the above-mentioned. That is, since the corner portion of the side surface portion of the lead wire is further acute, it can be easily bite into the electrode foil by this pressing, improving workability and improving the connection between the lead wire and the electrode foil. An improvement is obtained.
[0012]
The ultrasonic energy is applied by an ultrasonic welding horn having a single welding projection. That is, in order to connect the lead wire and the electrode foil in a small electrolytic capacitor, the mechanical strength after welding can be increased by welding with a single projection for welding.
[0013]
In the electrolytic capacitor manufacturing apparatus of the present invention, a lead wire and an electrode foil are disposed between an ultrasonic welding horn and an anvil, and the ultrasonic wave of the electrolytic capacitor is welded to the lead wire and the electrode foil by the ultrasonic welding horn. In the welding apparatus, the anvil includes a protrusion for pressing a side surface portion of the lead wire.
[0014]
That is, when the lead wire and the electrode foil are pressed against the anvil by the ultrasonic welding horn, the side surface portion of the lead wire is pressed against the electrode foil by the projection, and the lead wire and the electrode foil are fixed. The thickness of the lead wire is thin, and therefore the sharp side surfaces can be easily warped, and the lead wire and the electrode foil must be securely fixed in the lead wire of a small electrolytic capacitor with a very limited welding range. And the workability is greatly improved. In addition, by simply changing the height of the projection of the anvil according to the ultrasonic energy force from the ultrasonic welding horn, the fixing of the lead wire and the electrode foil can be easily achieved during welding, It is possible to manufacture an electrolytic capacitor having sufficient strength and electrical reliability.
[0015]
The electrolytic capacitor manufacturing apparatus according to the present invention is characterized in that the projection of the anvil is disposed so as to hold at least a corner portion of the side surface portion of the lead wire. That is, since the corner portion of the side surface portion of the lead wire is further acute, it can be easily bent and fixed to the electrode foil, improving workability and connecting the lead wire and the electrode foil in the manufactured electrolytic capacitor. Also improves.
[0016]
The apparatus for manufacturing an electrolytic capacitor according to the present invention is characterized in that the ultrasonic welding horn has a single welding projection at its tip. That is, by welding with a single welding projection, it is possible to easily achieve the connection between the lead wire and the electrode foil in a small electrolytic capacitor.
[0017]
In the electrolytic capacitor manufacturing apparatus according to the present invention, the ultrasonic welding horn includes a storage portion for storing the projection of the anvil. That is, an anvil projection housing part is provided to house the electrode foil, the lead wire whose side surface is pressed against the electrode foil, and the projection, whereby the lead wire and the electrode foil can be securely fixed, and the ultrasonic energy is reduced. Deviation during application is prevented.
[0018]
The electrolytic capacitor of the present invention is an electrolytic capacitor in which a lead wire and an electrode foil are connected by ultrasonic welding connection, and the lead wire and the electrode foil are overlapped and formed at the center of the overlapping portion. The lead wire and the electrode foil are connected by a connection portion formed by ultrasonic welding and a pressing portion formed by pressing a side surface portion of the lead wire.
[0019]
That is, the side surface portion of the lead wire, which is thin and therefore has an acute angle, is pressed and fixed to the electrode foil, and is ultrasonically welded, so there is no rotation or displacement, and the lead wire is not welded. Since the lead wire and the electrode foil are fixed by being pressed against the electrode foil by the side surface portion, the mechanical strength is high and the reliability of ultrasonic welding is high.
[0020]
Further , at least a corner portion of the side surface portion of the lead wire is pressed. That is, since it is fixed by an acute corner portion among the side portions of the lead wire, the connectivity between the lead wire and the electrode foil can be improved.
[0021]
【Example】
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an ultrasonic welding horn and an anvil as an ultrasonic welding apparatus for an electrolytic capacitor according to an embodiment of the present invention.
[0022]
The electrolytic capacitor ultrasonic welding horn 1 is formed by using a metal material such as steel, and a single welding projection 7 is formed at the tip of the horn 1 and ultrasonic waves are generated from an ultrasonic vibration source (not shown). In this configuration, energy is applied.
[0023]
The ultrasonic welding horn 1 has a prismatic shape. For example, as shown in FIG. 1A, the ultrasonic welding horn 1 includes a projection 5 having a sharp point such as a polygonal pyramid at the center as the projection 5 for welding. . The protrusion 5 is formed by knurling or the like.
[0024]
The protrusion 5 is a quadrangular pyramid having a square bottom surface and a pointed sharp portion, and has an acute apex angle, and each side surface forming the protrusion 5 is an isosceles triangle. The height of the protrusion 5 is set according to the thickness and the welding depth of the lead wire 3 and the electrode foil 4 which are members to be welded. Further, the corner portion of the ultrasonic welding horn 1 is chamfered to be tapered, and a storage portion 6 for storing a projection 7 of the anvil 2 described later is provided. In addition to this, the storage portion 6 may be formed with a groove, and the taper and the groove may have an arc shape in a top view. Further, the surface of the storage portion 6 that contacts the electrode foil 4 may be a flat surface or a curved surface. The depth of the storage portion 6 is appropriately set according to the thickness of the lead wire 3 and the electrode foil 4 which are members to be welded.
[0025]
The anvil 2 has a prismatic shape, and a minute unevenness 16 for preventing slip is formed on the top surface, and a projection 7 for warping the corner portion 14 of the side surface portion 15 of the lead wire 3 is formed on the corner portion. . As shown in FIG. 1 (b), the protrusion 7 is a pyramid having a bottom surface of an isosceles triangle and is formed to extend from the side surface of the corner of the prismatic anvil 2. Other protrusions 7 include a cone, an elliptical cone, and a fan-shaped cone having a bottom surface, and a surface contacting the lead wire 3 may be a curved surface in addition to a flat surface. The protrusion 7 has a sharp tip, which is preferable because the side portion 15 of the lead wire 3 can be easily pressed, and thus can easily bite into the electrode foil 4, but the tip may be a surface. The height of the protrusion 7 is appropriately set according to the thickness of the lead wire 3 and the electrode foil 4 and the pressing depth of the lead wire 3 against the electrode foil 4.
[0026]
Next, FIGS. 2A and 2B show a method for manufacturing an electrolytic capacitor according to an embodiment of the present invention.
[0027]
The electrolytic capacitor includes an outer case in which a capacitor element is enclosed, and an opening of the outer case is sealed with a sealing member made of elastic rubber having a through hole through which the lead wire 3 is inserted.
[0028]
The lead wire 3 is formed by pressing a part of a bar-shaped member made of aluminum to form a flat portion 10 and a round bar portion 9 and welding the CP wire 8 made of a wire to the round bar portion 9. The lead wire 3 is mainly composed of the same material as the electrode foil 4 such as aluminum, an anode foil having an etching layer and an oxide film layer formed thereon, and a cathode having an etching layer formed on the surface. Connected to each of the foils. The ultrasonic welding method of this lead wire 3 and both electrode foils 4 is described below.
[0029]
As shown to Fig.2 (a), the lead wire 3 and the electrode foil 4 are piled up and arrange | positioned on the anvil 2 of the ultrasonic welding apparatus which concerns on this invention. The overlapping portion is arranged so that the protruding portion 7 of the ultrasonic welding horn 1 comes to the approximate center. The electrode foil 4 has a width of 1.5 mm, a thickness of 0.1 mm, and the flat portion 10 of the lead wire 3 has a width of 1 mm, a length of 2 mm, and a thickness of 0.2 mm. 3 is placed on the anvil 2 with its ends aligned. In the present invention, it is preferable that the dimensions of the superimposed lead wire 3 and electrode foil 4 are smaller than 2 mm in both width and length.
[0030]
Next, when the lead wire 3 and the electrode foil 4 are placed on the anvil 2, the ultrasonic welding horn 1 is brought into contact with the electrode foil 4 from above as shown in FIG. Pressed. The lead wire 3 and the electrode foil 4 are sandwiched and pressed between the abutment surface 11 of the welding projection 5 and the storage portion 6 of the ultrasonic welding horn 1 and the abutment surface 11 and the projection 7 of the anvil 2, and the The protrusion 14 of the anvil 2 presses the corner 14 of the flat portion 10 of the lead wire 3 and presses against the electrode foil 4 to bite in a small amount, and the lead wire 3 and the electrode foil 4 are fixed and positioned. Then, ultrasonic energy is applied as shown by an arrow from an ultrasonic welding source (not shown) together with the applied pressure, and the lead wire 3 and the electrode foil 4 are welded.
[0031]
Next, (a) and (b) of FIG. 3 show the connection state of the lead wire 3 and the electrode foil 4 connected by the electrolytic capacitor manufacturing method according to the embodiment of the present invention.
[0032]
First, as shown in FIG. 3 (a), the connection portion 12 by the welding projection 5 of the ultrasonic welding horn 1 and the corner portion 14 of the lead wire 3 are located near the center of the flat portion 10 of the lead wire 3. A pressing portion 13 pressed against the electrode foil 4 by the protrusion 7 of the anvil 2 is formed. The corner portion 14 of the flat portion 10 of the lead wire 3 can be easily pressed against the electrode foil 4, and the lead wire 3 and the electrode foil 4 can be easily fixed at the time of ultrasonic welding. 3 and the electrode foil 4 can be easily connected. In addition, after welding, and also in the completed electrolytic capacitor, the corner 14 of the flat portion 10 of the pressed lead wire 3 is kept fixed to the electrode foil 4, and mechanical stress such as forming of the lead wire 3 is maintained. Even when is added, the connection between the lead wire 3 and the electrode foil 4 is good. As another method of fixing the lead wire 3 and the electrode foil 4, a part of the side surface portion 15 of the flat portion 10 of the lead wire 3 is pressed against the electrode foil 4, or as shown in FIG. Further, the side surface portion 15 and the corner portion 14 of the flat portion 10 of the lead wire 3 can be combined and pressed. A protrusion 7 is provided on the anvil 2 in accordance with the position where the lead wire 3 flat portion 10 is pressed against the electrode foil 4.
[0033]
And when the lead wire 3 and both electrode foils 4 are respectively connected by ultrasonic welding, the separator made of electrolytic paper or the like is interposed between the electrode foils 4, that is, the anode foil and the cathode foil, and is wound. A capacitor element is formed. This capacitor element is housed in the outer case as described above, and the opening is sealed with a sealing member to complete the electrolytic capacitor.
[0034]
【The invention's effect】
As described above, according to the method for manufacturing an electrolytic capacitor of the present invention, at the time of welding, the thickness of the lead wire is thin, and therefore, the side portion having an acute angle is pressed and fixed to the electrode foil. Welding is easy, and displacement between the lead wire and electrode foil during welding is suppressed, welding strength is high, and a reliable connection state is obtained, and the electrolytic capacitor has resistance against vibration stress. A welded structure can be realized.
[0035]
Further, according to the ultrasonic capacitor ultrasonic welding apparatus of the present invention, the lead wire and the electrode foil can be fixed by pressing the side surface portion of the lead wire against the electrode foil side by the protrusion provided on the anvil, and welding is performed. A highly reliable connection with the lead wire of a small electrolytic capacitor with a very limited range can be achieved.
[0036]
In addition, according to the electrolytic capacitor of the present invention, the side portion of the lead wire, which is thin and therefore acute, is pressed and fixed to the electrode foil and ultrasonically welded, so there is no rotation or displacement, Moreover, since the lead wire and the electrode foil are fixed by pressing the side surface of the lead wire against the electrode foil even after welding, the mechanical strength is high and the reliability of ultrasonic welding is high.
[Brief description of the drawings]
FIG. 1 is a view showing a horn and an anvil of an ultrasonic welding apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram showing a welding process of a lead wire and an electrode foil using an ultrasonic welding apparatus according to an embodiment of the present invention.
FIG. 3 is a top view showing a connection state between lead wires and electrode foils connected by an ultrasonic welding apparatus according to an embodiment of the present invention.
FIG. 4 is a view showing a horn and an anvil of a conventional ultrasonic welding apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ultrasonic welding horn 2 Anvil 3 Lead wire 4 Electrode foil 5 Protrusion part 6 Storage part 7 Protrusion 8 CP wire 9 Round bar part 10 Flat part 11 Contact surface 12 Connection part 13 Press part 14 Corner part 15 Side part 16 Concavity and convexity

Claims (6)

A method of manufacturing an electrolytic capacitor in which a lead wire and an electrode foil are overlapped and welded by applying ultrasonic energy, and at least a corner portion of a side surface portion of the lead wire is pressed and a process of overlapping the lead wire and the electrode foil The manufacturing method of the electrolytic capacitor including a process and the process which gives and welds ultrasonic energy, pressurizing to the overlapping part of a lead wire and electrode foil. The method for manufacturing an electrolytic capacitor according to claim 1 , wherein the ultrasonic energy is applied by an ultrasonic welding horn having a single welding projection. An electrolytic capacitor ultrasonic welding apparatus in which a lead wire and an electrode foil are disposed between an ultrasonic welding horn and an anvil, and the lead wire and the electrode foil are welded by the ultrasonic welding horn. The anvil is an ultrasonic welding apparatus for an electrolytic capacitor provided with a protrusion for pressing at least a corner portion of a side surface portion of the lead wire. The ultrasonic welding apparatus for an electrolytic capacitor according to claim 3 , wherein the ultrasonic welding horn includes a single welding projection at a tip thereof. 5. The electrolytic capacitor ultrasonic welding apparatus according to claim 3, wherein the ultrasonic welding horn includes a storage portion that stores the projection of the anvil. An electrolytic capacitor in which a lead wire and an electrode foil are connected by ultrasonic welding connection, wherein the lead wire and the electrode foil are overlapped, and a connecting portion by ultrasonic welding formed at the center of the overlapping portion, and a lead An electrolytic capacitor in which a lead wire and an electrode foil are connected by a pressing portion formed by pressing at least a corner portion of a side surface portion of the wire.

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