JPS6314863B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to an electrolytic capacitor and a method for manufacturing the same. [Technical Background of the Invention and Problems Therewith] Large-capacity electrolytic capacitors used for smoothing power supplies, etc., use solderable plate terminals or screw terminals as external terminals. Therefore, aluminum strip-shaped terminals (hereinafter referred to as tabs) are often used as so-called internal terminals that connect both poles of a capacitor element and external terminals. In addition, for relatively large large-capacity electrolytic capacitors, a vibration damping agent such as pitch, wax, or attic polypropylene is filled between the element inside the storage case and the case to secure the element. In some small devices, the axial dimension of the element is made almost equal to that of the storage case, and the pressure of an external terminal board attached to the open end of the storage case is used to press the element against the storage case and protect it from vibration. . Additionally, as electronic devices have become thinner in recent years, electrolytic capacitors whose diameter is larger than their axial dimension have appeared, but even in this type of capacitors, protection of the element by the pressure of the external terminal board is used. There is. As mentioned above, if the device is fixed by the pressure of the external terminal board, a burden will naturally be placed on the device. That is, the element is constructed by overlapping and winding an anode foil, a cathode foil, and a spacer paper slightly wider than these, and a layer in which these are alternately wound is formed on the end face of the element. When applying pressure to the element with the external terminal plate, the tab is pressed against the end face to the extent that it sinks into the element end face. Therefore, the tab may come into contact with the anode foil or the cathode foil, causing a short circuit. As mentioned above, the width of the spacer paper is slightly wider than that of the anode foil and cathode foil, so when the tab is pressed, it does not tear through the spacer paper covering the edges of the anode foil and cathode foil. No short circuit will occur as long as the However, due to the demand for miniaturization of electronic devices, the difference in width between each electrode foil and spacer tends to be small in order to store more capacitance in a storage case of the same size, and short circuits due to pressing of tabs tend to occur. The risk of an outbreak is increasing.
Also, when the tab is bent at right angles, the wider side of the tab is not necessarily parallel to the end face of the element, and due to variations in the manufacturing process, this side may It may be installed at an angle to the end face. In such a case, the thickness direction of the tab, that is, both end surfaces, will be pressed against the element end surface, and the tab will very easily sink into the element end surface, making it easy to cause a short circuit. In order to prevent a short circuit caused by the tab when applying pressure to the external terminal board as described above, conventional methods have been taken such as covering the tab with an insulating tube or coating the tab with an insulating paint. In the case of the former method,
It is necessary to cover each tab with an insulating tube and then rivet it to the external terminal board, making automation difficult and low productivity. Also, when storing an element with an external terminal board attached in a storage case, the external terminal board and the element may be twisted, causing the tabs of both poles to overlap. If the tab sinks into the end face, there is a risk that the spacer paper will break and a short circuit will occur between the anode foil and the cathode foil. When using the latter method of applying an insulating paint, it is necessary to select an insulating paint that is not corroded by the driving electrolyte. Also, when storing the device with the external terminal board attached in the storage case, the tab is bent, but this bending can crack the coating and expose the aluminum surface, which may cause a short circuit.
Even if the two electrode tabs come into contact, the coating film may be destroyed and a short circuit may occur. [Object of the Invention] The present invention has been made based on the above-mentioned circumstances, and it is possible to protect the device from vibration by the pressure of the external terminal board, and there is no risk of short circuit due to the tab, and furthermore, it is an electrolytic method that can be easily automated in manufacturing. The purpose is to obtain capacitors and methods for manufacturing them. [Summary of the Invention] The electrolytic capacitor of the present invention has a laminate film formed by laminating and integrating a heat-fusible resin film and an insulating resin film onto a strip-shaped terminal that connects an electrode of an element and an external terminal. It is characterized in that it is used as an insulating piece for the internal terminal. In addition, the manufacturing method of the present invention includes a step of shaping the internal terminals connected to the electrodes of the element so that their wide surfaces are in the same plane, and a process of forming a heat-fusible resin film and an insulating film on both sides of the internal terminals. A step of heat-pressing a laminated tape made by laminating and integrating resin films, a step of cutting the internal terminal to a predetermined size and drilling a rivet hole, and a step of attaching the external terminal board and the external terminal with the rivet inserted into the rivet hole. and a step of cutting the laminate tape into individual elements. [Embodiments of the Invention] FIG. 1A shows a laminate film used in the present invention. The laminate film 1 is formed by laminating and integrating a heat-fusible resin film 1a and a polyester film 1b. FIG. 1B shows one embodiment of the invention. The laminate film 1 shown in FIG.
An insulating piece 5 cut into a rectangular shape to the length to which insulation is to be applied to the tabs 3 and 4 is attached to the tabs 3 and 4 with the heat-fusible resin film facing the wide surfaces of the tabs 3 and 4.
are engaged with both sides and bonded under heat and pressure. In addition,
In the figure, 6 indicates an external terminal board. FIG. 1C shows another embodiment. In this embodiment, an insulating piece 7 spanning between the tabs 3 and 4 is heat-pressed to the tabs 3 and 4. The electrolytic capacitor of the present invention is manufactured as follows. That is, as shown in FIG. 2A, the tabs 3 and 4 are often not attached to the element 2 so that their wider surfaces lie in the same plane. Therefore, the tabs 3 and 4 are pressed against a surface plate or the like using a press or other means so that they are in the same plane as shown in FIG. 2B. Next, as shown in FIG. 2C, a tab is inserted between the heat-fusible resin films of the two tapes 8 made of the laminate film shown in FIG. 1A, and they are heat-pressed. Furthermore, the tab is cut to a certain size and the rivet hole 9 is
The external terminal plate 6 is attached to the tabs 3 and 4 using the rivet 10 inserted into the rivet hole 9. External terminal 11 to this external terminal board 6
After attaching, cut the tape 8 on the outside of the tabs 3 and 4 as shown in FIG. 2D, and then bend the tabs 3 and 4 as shown in FIG. parallel to. Finally, the element is stored in the storage case, and pressure is applied to the external terminal plate 6 to secure it to the case opening by caulking or the like. In addition, if the tape between the tabs 3 and 4 is cut in the tape cutting process shown in FIG. 2D, the result shown in FIG.
This is the example shown in . In the electrolytic capacitor of the present invention, the tabs are shaped so that their wide surfaces lie on the same plane before attaching the insulating pieces to the tabs, and the tabs are further shaped during heat-pressing of the tape forming the insulating pieces. The tape is cut after the tab has been fixed to the external terminal board, so even if the tab is bent until it is parallel to the element end surface, the end surface of the tab does not face the element end face.
Further, in the embodiment shown in FIG. 2C, the element and the external terminal board will not be twisted and the tabs will not overlap when inserted into the storage case. Therefore, when pressure is applied to the external terminal board, there is no risk of short circuiting due to the end face of the tab sinking into the end face of the element. Additionally, the laminate film has a high withstand voltage and exhibits sufficient properties to protect the tab. Furthermore, the steps shown in FIGS. 2A to 2E can be easily automated, and high productivity can be expected. The table below shows test results for the electrolytic capacitor of the present invention manufactured by the above process and a conventional electrolytic capacitor whose tabs were insulated by an insulating tube.

[Table] [Effects of the Invention] According to the present invention, since there is no fear of short circuit due to tabs, it is possible to further promote miniaturization of electrolytic capacitors. Furthermore, automation of manufacturing can reduce costs and improve quality.

[Brief explanation of the drawing]

FIG. 1A is a perspective view showing an example of a laminate film used in the present invention, FIG. 1B is a perspective view of one embodiment of the present invention, FIG. 1C is a perspective view of another embodiment, and FIG. 2A -E are perspective views sequentially showing the steps of the manufacturing method of the present invention. 1... Laminate film, 1a... Heat-fusible resin film, 1b... Polyester film,
2... Element, 3, 4... Tab, 5, 7... Insulating piece, 6... External terminal board, 8... Laminate tape, 9... Rivet hole, 10... Rivet.

Claims (1)

[Claims] 1. A laminate film made by laminating and integrating a heat-fusible resin film and an insulating resin film is heat-pressed onto a strip-shaped terminal that connects an electrode of an element and an external terminal to insulate the internal terminal. An electrode capacitor characterized by a single piece. 2. Shaping the internal terminals connected to the electrodes of the element so that their wide surfaces are in the same plane;
A step of heat-pressing a laminate tape formed by laminating a heat-fusible resin film and an insulating resin film on both sides of the internal terminal, a step of cutting the internal terminal to a predetermined size and drilling a rivet hole, and a step of forming the rivet hole. 1. A method for manufacturing an electrolytic capacitor, comprising the steps of: attaching an external terminal board and external terminals with rivets inserted into the capacitor; and cutting a laminate tape into individual elements.