JP5050235B2 - Metal foil connection method - Google Patents

Description

The present invention relates to a connection METHODS metal foil for connecting a plurality of metal foils between which are stacked.

  In a conventional method of manufacturing a capacitor (capacitor), a bundle of lead portions of a plurality of stacked collector electrodes (metal foils) are stacked on an electrode terminal and set in an ultrasonic welding machine. Is sandwiched between the welding head and the ampil, and while applying pressure, ultrasonic vibration is applied from the ultrasonic welding surface of the welding head and welding is performed using frictional heat generated by the vibration. The electrode terminal is connected (for example, refer to Patent Document 1).

  In addition, an aluminum foil (metal foil) having an oxide film as an insulating film on the surface is used for the electrode of the capacitor. When manufacturing a capacitor using this aluminum foil, the laminated aluminum foil is preliminarily formed. A small hole is drilled, the oxide film of the aluminum foil is removed along the inner surface of the small hole, and the electrode of the resistance welder is pressed against the area to be crimped centered on the small hole, and the electrode is energized for resistance welding. The laminated aluminum foils are connected to each other (for example, see Patent Document 2).

Japanese Patent Laid-Open No. 2002-198262 (page 2, FIG. 1) JP 2006-326622 A (page 4, FIG. 5)

  However, in the method for manufacturing a capacitor (capacitor) described in Patent Document 1, since the collector electrodes (metal foils) are simply welded using frictional heat generated by ultrasonic vibration, the lead portions of the collector electrodes There is a problem in that the connection strength of the bundle of fibers becomes weak.

  Moreover, in the resistance welding method of the laminated aluminum foil (metal foil) described in Patent Document 2, small holes to be drilled in the aluminum foil must be formed in a predetermined size, and the resistance welding work is complicated. become. If the small hole size is small, drilling becomes difficult, and if the small hole size is large, the small hole may not be completely closed after resistance welding. There is a problem that the number of sheets to be limited is limited.

The present invention has been made paying attention to such problems, and any size and number of metal foils can be connected by simplified connection work, and the connection strength between the metal foils can be increased. and to provide a connection mETHODS metal foil can be improved.

In order to solve the above problems, a method of connecting the metal foil of claim 1 of the present invention,
A metal foil connection method for connecting a plurality of laminated metal foils,
Laminating a plurality of the metal foils, arranging at least two connecting members so as to continuously contact each end of the metal foil , attaching an anode of a resistance welding apparatus to one connecting member, and A cathode of a resistance welding apparatus is attached to the connection body , and resistance welding is performed by flowing an electric current while pressing the connection body toward the metal foil, thereby connecting the connection body and the metal foil. .
According to this feature, since the connection body is arranged at the end of the metal foil and resistance welding is performed, it is not necessary to perform resistance welding processing on the metal foil, and the connection work between the laminated metal foils is simple In addition, the metal foil of any size and number can be connected, and each metal foil is once melted and connected to each other by resistance welding. The connection strength between the foil and the connection body can be improved. And the connection work can be performed using the anode and cathode of the resistance welding apparatus, and there is no need to separately connect the electrode of the resistance welding apparatus to the metal foil, and the metal foils can be connected to each other or between the metal foil and the connection body. Work can be simplified.

The metal foil connection method according to claim 2 of the present invention is the metal foil connection method according to claim 1 ,
The resistance welding is performed while pressing the stacked metal foils in the stacking direction.
According to this feature, resistance welding is performed without forming a gap between the laminated metal foils, and the portions of the metal foils once melted are firmly connected.

The metal foil connection method according to claim 3 of the present invention is the metal foil connection method according to claim 1 or 2 ,
Each of the end portions of the laminated metal foils is arranged in a flat shape before performing resistance welding.
According to this feature, if the end portions of the laminated metal foils are arranged in a planar shape, the end portions of the respective metal foils can be brought into contact with the connecting body uniformly, and the end portions of the laminated metal foils It becomes easy to join the connection body by resistance welding.

It is described below with reference to the best mode embodiment for carrying out the connection METHODS metal foil according to the present invention.

  An embodiment of the present invention will be described with reference to the drawings. First, FIG. 1 is a perspective view showing a capacitor element in Embodiment 1, and FIG. 2 is a perspective view showing a tab portion of laminated aluminum foil, FIG. 3 is a front view showing the tab portion of the aluminum foil when resistance welding is performed, and FIG. 4A is an enlarged front view showing the tab portion of the aluminum foil after resistance welding, and FIG. ) Is an enlarged side sectional view showing a tab portion of the aluminum foil after resistance welding.

  Reference numeral 1 in FIG. 1 denotes a capacitor element to which the present invention is applied for use in an electrolytic capacitor or the like. The capacitor element 1 is formed by laminating a plurality of aluminum foils 2 as metal foils in the present embodiment, and the aluminum foil for the anode is enlarged by an etching process, and an oxide film layer is formed thereon. The aluminum foil for the cathode is enlarged by an etching process. The anode aluminum foil 2 and the cathode aluminum foil 2 are alternately laminated, and a separator (not shown) is disposed between the aluminum foil 2 for the anode foil and the aluminum foil 2 for the cathode foil. Yes.

  As shown in FIG. 1, each aluminum foil 2 is formed with a tab portion 3. The tab portions 3 for the anode foil are bundled together, and the tab portions 3 for the cathode foil are bundled together. . The anode tab portion 3 is formed so that the oxide film layer provided on the surface is removed or not present in advance. Two connecting lines 4 as connecting bodies in the present embodiment are connected to the upper end edge (end portion) of the bundle of tab portions 3 respectively. The tab portions 3 and the bundle of the tab portions 3 and the connection line 4 are connected by resistance welding performed by passing a current while pressing. The connecting wire 4 is formed in a linear shape using aluminum which is the same material as the aluminum foil 2.

  Next, a method for connecting the tab portions 3 using resistance welding will be described. As illustrated in FIG. 2, the stacked tab portions 3 are sandwiched by the sandwiching member 5 from both front and rear surfaces, and the stacked tab portions 3 are pressed together by pressing the bundle of tab portions 3 from the front and rear direction (stacking direction). Remove the gap between. Then, the two connecting wires 4 are brought into contact with the upper edge of the bundle of tab portions 3. The connection line 4 is disposed so as to extend in the front-rear direction (stacking direction), and is continuously in contact with the upper end edge of each tab portion 3. At this time, the upper end edge of the bundle of tab portions 3 is formed in a planar shape by a technique such as polishing, grinding, or cutting.

  As shown in FIG. 3, an electrode 6 of a resistance welding apparatus is attached to each connection line 4 that is in contact with the bundle of tab portions 3. In order to increase the contact area with the connection line 4, the electrode 6 includes a recess adapted to the outer peripheral surface of the connection line 4, and the contact area with the connection line 4 is increased by attaching the contact line 4 to the recess. At the same time, the connecting wire 4 is guided to a predetermined position and positioned by the recess. Of the two connection wires 4 that are in contact with the bundle of tab portions 3, one connection wire 4 is attached with an electrode 6 on the anode side of the resistance welding apparatus, and the other connection wire 4 has An electrode 6 on the cathode side of the resistance welding apparatus is attached. Furthermore, the two connection lines 4 are arranged separated by a predetermined distance.

  The electrode 6 of the resistance welding apparatus can press the entire longitudinal direction (front-rear direction) of the connecting wire 4 toward the tab portion 3. Resistance welding is performed by flowing a welding current E between the electrodes 6 and 6 while pressing the connecting wire 4 toward the tab portion 3 by the electrode 6 of this resistance welding apparatus.

  The welding current E flowing from the anode electrode 6 flows into the tab portion 3 from one connection line 4 and flows from the other connection line 4 toward the cathode electrode 6. At this time, heat is generated by electrical resistance between the connecting wire 4 and the tab portion 3, and the connecting wire 4 and a part of the tab portion 3 are once melted by the resistance heat to form the welded portion 7. By reducing the contact area between the connection wire 4 and the tab portion 3 (point contact), the contact resistance can be increased and local heat generation at the contact portion can be generated, and the connection wire 4 and the tab portion 3 can be efficiently produced. Can be melted.

  As shown in FIG. 4A, since the welded portion 7 is formed at the contact portion of the tab portion 3 with the connecting wire 4, the tab portion 3 and the connecting wire 4 are firmly connected by the welded portion 7. Is done. Further, as shown in FIG. 4B, the welded portion 7 is formed so as to extend in the front-rear direction (stacking direction) of the bundle of tab portions 3, so that the tab portions 3 are firmly connected to each other by the welded portion 7. Is done.

  As described above, in the metal foil connection structure and the connection method in the present embodiment, the connection lines 4 are arranged so as to continuously contact the respective end portions of the tab portions 3 of the laminated aluminum foils 2. The connection wire 4 and the tab portion 3 are connected by resistance welding performed by flowing a welding current E while pressing the tab portion 3 toward the tab portion 3, so that the tab portion 3 of the aluminum foil 2 is used for resistance welding. There is no need for processing, etc., and not only is the work of connecting the laminated aluminum foils 2 simplified, but any size and number of tabs 3 of the aluminum foil 2 can be connected. In addition, since the tab portions 3 are once melted and connected to each other by resistance welding, the connection strength between the tab portions 3 or between the tab portions 3 and the connection wires 4 can be improved.

  In addition, since the two connection wires 4 are connected to the bundle of tab portions 3 of the aluminum foil 2, the tab portions 3 are connected to each other via the two connection wires 4, and the connection strength is improved. be able to.

  Further, since the aluminum foil 2 and the connecting wire 4 are formed of the same material, the tab portion 3 of the aluminum foil 2 melted by resistance welding and the connecting wire 4 are easily connected, and its connection strength. Can be improved.

  In addition, in the metal foil connection structure and the connection method in this embodiment, any size and number of aluminum foils 2 can be connected by a simplified connection operation, and the connection strength between the aluminum foils 2 can be reduced. A capacitor including the capacitor element 1 with improved can be manufactured.

  Further, two connection wires 4 are arranged in a bundle of tab portions 3 of the aluminum foil 2, and an electrode 6 for an anode of a resistance welding device is attached to one connection wire 4, and a resistance welding device is attached to the other connection wire 4. By attaching the cathode electrode 6, the connection work can be performed using the connecting wire 4 as the anode and cathode of the resistance welding apparatus, and the work of separately connecting the resistance welding apparatus electrode 6 to the aluminum foil 2 is not necessary. The connecting work between the connecting wire 4 and the aluminum foil 2 can be simplified.

  Further, by performing resistance welding while pressing the bundle of tab portions 3 of the laminated aluminum foil 2 in the laminating direction, resistance welding is performed without forming a gap between the laminated tab portions 3. The parts of the melted tab portion 3 are firmly connected to each other.

  If the end portions of the laminated aluminum foils 2 are aligned in a flat shape before the resistance welding is performed, the end portions of the respective aluminum foils 2 are aligned. Can contact the connecting wire 4 uniformly, and the end of the laminated aluminum foil 2 and the connecting wire 4 are easily joined by resistance welding.

  Next, a metal foil connection structure and a connection method thereof according to Example 2 will be described with reference to FIG. It should be noted that the same components as those shown in the above-described embodiment are denoted by the same reference numerals and redundant description is omitted. FIG. 5 is a front view showing a tab portion of an aluminum foil when performing resistance welding in the second embodiment.

  Unlike the capacitor element 1 of the first embodiment, the capacitor element 1 ′ in the second embodiment has a single connection line 4 arranged in a bundle of tab portions 3 of the aluminum foil 2 as shown in FIG. 5. At the time of connection work, the anode electrode 6 of the resistance welding apparatus is attached to the connection line 4, and the cathode electrode 6 ′ of the resistance welding apparatus is attached to a portion of the aluminum foil 2 near the tab portion 3. It is done. Then, resistance welding is performed by flowing a welding current E between the electrodes 6 and 6 ′ while pressing the connecting wire 4 toward the tab portion 3 by the anode electrode 6 of the resistance welding apparatus. The cathode electrode 6 ′ preferably has a large contact area with the tab portion 3 in order to reduce the contact resistance with the tab portion 3 in contact with the cathode electrode 6 ′.

  The welding current E flowing from the anode electrode 6 flows into the aluminum foil 2 from the tab portion 3 via the connection line 4 and flows toward the cathode electrode 6 ′ attached to the aluminum foil 2. At this time, heat is generated by electrical resistance between the connection wire 4 and the tab portion 3, and the connection wire 4 and a part of the tab portion 3 are once melted by the resistance heat, and the tab portion 3 and the connection wire 4. Are firmly connected.

  Next, a metal foil connection structure and a connection method thereof according to Example 3 will be described with reference to FIG. It should be noted that the same components as those shown in the above-described embodiment are denoted by the same reference numerals and redundant description is omitted. FIG. 6 is a side sectional view showing the capacitor element according to the third embodiment.

  The capacitor element 8 according to the third embodiment is a multilayer capacitor in which a plurality (four in FIG. 6) of single plate capacitors 9 are stacked and the cathode portion of each single plate capacitor 9 is electrically and mechanically joined with a silver paste 10. Element 8. Each single plate capacitor 9 has an anode portion 11 (metal foil) led out laterally from the capacitor body, and is mechanically and electrically connected by welding each anode portion 11.

  First, an aluminum foil (or plate material) is cut into a strip shape as a metal foil, and a predetermined region of the aluminum foil is anodized in a chemical solution such as adipic acid, phosphoric acid or boric acid to form an oxide film. To do. Next, a conductive polymer layer such as polyethylenedioxythiophene that becomes a solid electrolyte is formed on the surface of the oxide film by electrolytic polymerization or chemical polymerization. Thereafter, a cathode drawing graphite layer and a silver paste layer are sequentially formed on the surface of the conductive polymer layer. Thereafter, the anode 11 removes the oxide film formed on the surface by polishing, grinding, etc., and exposes the aluminum surface. Note that the oxide film may not be formed in advance on the anode portion 11 by masking or the like. In this way, the single plate capacitor 9 is obtained. Examples of the film-forming metal having a valve action include aluminum, tantalum, and titanium.

  Next, a plurality of single plate capacitors 9 are stacked, and the silver paste layers of each single plate capacitor 9 are electrically and mechanically joined with the silver paste 10. Then, the anode part 11 of each single plate capacitor 9 is bundled. At this time, as in the first embodiment, the edge of the anode portion 11 is formed in a planar shape by a technique such as polishing, grinding, or cutting.

  A sandwiching member 12 sandwiches the bundle of stacked anode portions 11 from both the upper and lower surfaces, and presses the bundle of anode portions 11 from the up and down direction (stacking direction) to eliminate a gap between the stacked anode portions 11. Then, the two connecting wires 13 (connectors) are brought into contact with the edge of the bundle of the anode portions 11. The connection line 13 is formed using copper that can be joined by a conductive adhesive. The connection line 13 is disposed so as to extend in the vertical direction (stacking direction), and is continuously in contact with the edge of each anode portion 11. In addition, as shown in Example 2, resistance welding with one connection line 13 (connection body) can also be performed.

  As shown in FIG. 6, an electrode 14 of a resistance welding apparatus is attached to each connection line 13 in contact with the bundle of anode portions 11. As in Example 1, the electrode 14 on the anode side of the resistance welding apparatus is attached to one of the two connection wires 13 that are in contact with the bundle of the anode portions 11, and the other The electrode 14 on the cathode side of the resistance welding apparatus is attached to the connection line 13. Furthermore, the two connection lines 13 are arranged with a predetermined distance therebetween.

  The electrode 14 of the resistance welding apparatus can press the entire longitudinal direction (vertical direction) of the connecting wire 13 toward the anode portion 11. Moreover, the shape of the electrode 14 of the resistance welding apparatus includes a concave portion adapted to the outer peripheral surface of the connection line 13 in order to increase the contact area with the connection line 13 as shown in the first embodiment. Resistance welding is performed by flowing a welding current between the electrodes 14 and 14 in the same manner as in Example 1 while pressing the connecting wire 13 toward the anode portion 11 by the electrode 14 of the resistance welding apparatus.

  The welding current supplied from the anode electrode 14 flows into the anode portion 11 from one connection line 13 and flows from the other connection line 13 toward the cathode electrode 14. At this time, heat is generated by electrical resistance between the connecting wire 13 and the anode portion 11, and the connecting wire 13 and a part of the anode portion 11 are once melted and welded by the resistance heat.

  After the single plate capacitors 9 are formed, a plurality of the single plate capacitors 9 are stacked, the anode portions 11 of the single plate capacitors 9 are connected, and then the cathode portions of the single plate capacitors 9 are coated with the silver paste 10. The multilayer capacitor element 8 may be formed by bonding.

  An anode lead (or lead frame) is connected to the connecting wire 13 joined to the anode portion 11 of the multilayer capacitor element 8 with a conductive adhesive such as silver paste, and the cathode lead (or lead frame) is also connected to the cathode portion. Connect. Next, the multilayer capacitor element 8 is packaged in a predetermined shape with an epoxy resin or the like to complete a solid electrolytic capacitor.

  In addition, when bundling the anode part 11 of the single-plate capacitor | condenser 9, metal spacers, such as aluminum and copper, can also be interposed between the anode parts 11. FIG.

  Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to these embodiments, and modifications and additions within the scope of the present invention are included in the present invention. It is.

  For example, in each of the embodiments, an electrolytic capacitor and a solid electrolytic capacitor are exemplified as the capacitor, and the present invention is applied to the capacitor element of the electrolytic and solid capacitor. However, the present invention is not limited thereto, and the electric double layer capacitor is not limited thereto. It can be applied to various capacitors and capacitors such as electrochemical capacitors, and further to batteries.

  Moreover, in the said Example 1 and 2, the aluminum which is the same material as the aluminum foil 2 which is a metal foil for the connection wire 4 is illustrated, and in Example 3, the connection wire 4 is joined by a conductive adhesive. Although possible copper is illustrated, the connection wire 4 may be formed of a material different from the metal foil, for example, a material such as iron or stainless steel, as the connection wire 4.

  Moreover, in each Example, the shape of the connection line 4 is formed in the shape of a line, and is used by one-point line contact with the end of each tab part 3 (metal foil). The shape is not limited to a plate shape, and may be a plate shape, or a shape that can contact the end portion of each tab portion 3 (metal foil), such as line contact or surface contact at a plurality of points, and the end portion. As long as the contact resistance between the contact line and the connection line can be set higher than the contact resistance between the electrode 6 and the connection line 4 of the resistance welding apparatus, any shape may be used.

  In each embodiment, the two connection wires 4 are connected to the bundle of tab portions 3 of the aluminum foil 2 by resistance welding, but three, four, or more connection wires are connected to the bundle of tab portions 3. 4 may be connected by resistance welding.

3 is a perspective view showing a capacitor element in Example 1. FIG. It is a perspective view which shows the tab part of the laminated | stacked aluminum foil. It is a front view which shows the tab part of the aluminum foil at the time of performing resistance welding. (A) is an enlarged front view which shows the tab part of the aluminum foil after resistance welding, (b) is an enlarged side sectional view which shows the tab part of the aluminum foil after resistance welding. It is a front view which shows the tab part of the aluminum foil at the time of performing resistance welding in Example 2. FIG. 6 is a side cross-sectional view showing a capacitor element in Example 3. FIG.

Explanation of symbols

1,1 'Capacitor element 2 Aluminum foil (metal foil)
3 Tab 4 Connection line (connector)
5 Electrode 7 of sandwiching member 6, 6 'resistance welding apparatus 7 Welding part 8 Capacitor element 9 Single plate capacitor 10 Silver paste 11 Anode part (metal foil)
12 clamping member 13 connection line (connection body)
14 Electrodes of resistance welding equipment

Claims (3)

A metal foil connection method for connecting a plurality of laminated metal foils,
Laminating a plurality of the metal foils, arranging at least two connecting members so as to continuously contact each end of the metal foil , attaching an anode of a resistance welding apparatus to one connecting member, and A cathode of a resistance welding apparatus is attached to the connection body , and resistance welding is performed by flowing current while pressing the connection body toward the metal foil to connect the connection body and the metal foil. Metal foil connection method. While pressing the laminated metal foil in the stacking direction, a method of connecting the metal foil according to claim 1, characterized in that the resistance welding. 3. The method for connecting metal foils according to claim 1, wherein the end portions of the laminated metal foils are arranged in a planar shape before resistance welding. 4.

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