JPH0230829Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a thin film package type aluminum electrolytic capacitor.

[Technical background of the invention and its problems] The film package type electrolytic capacitor was the first
It is manufactured as shown in the figure. Namely, two-layer laminate tape of polyester film and ionomer sheet, three-layer laminate tape of polyester film, aluminum foil, and ionomer sheet, polyester film, aluminum foil, insulating layer,
Two tapes 1, such as a four-layer ionomer sheet laminated tape, are placed facing the surfaces of the ionomer sheets, and capacitor elements 2 are placed between them at regular intervals, followed by heat compression bonding and ultrasonic welding. The two tapes are bonded together by fusing their respective resins, the capacitor elements are sealed, and the tapes are cut between the elements to produce individual products.

Among the above-mentioned two-layer to four-layer laminate tapes, three-layer and four-layer laminate tapes with an aluminum foil interposed in the middle prevent paste electrolyte from permeating through the tape.

When bonding with heat, it is very difficult to control the degree of pressure and temperature; if the pressure and temperature are too high, 3 or 4 layer laminated tapes with aluminum foil may melt. The thermoplastic resin flowing away may come into contact with the aluminum foil and the lead-out terminals from the internal elements, resulting in shorting between the lead-out terminals and the capacitor not functioning.

In addition, if the pressure and temperature are insufficient, not only will the sealing of the peripheral area be incomplete, but also the contact with the thermoplastic resin will be incomplete at the anode and cathode lead terminals, and the element will be impregnated in advance. A certain paste electrolyte may leak from a small gap and cause a defect.

Ultrasonic welding has the disadvantage that it is difficult to bond the resin and metal, and even if the peripheral area is completely sealed, gaps may occur at the terminals, causing paste electrolyte to leak. be.

As mentioned above, the sealing of the film package is
The problem arises in the lead-out terminal portion, and the characteristics of the product are greatly influenced by how that portion is sealed.

There is a method disclosed in Japanese Patent Application Laid-Open No. 58-17384 as a measure to prevent short-circuiting of the outgoing terminal and to improve the sealing strength of the outgoing terminal against the stress of the external lead wire, but this is not easy to manufacture and the external lead There were drawbacks such as the need to prepare the wire as a separate material in advance and poor workability. In addition, attempts have been made to prevent short circuits by making the cross-sectional shape of the pull-out terminal 3 a convex lens shape as shown in FIGS. 2A and B, or by making both ends thinner, but this also prevents complete sealing. You can't get it.

[Purpose of the invention] The present invention was developed based on the above-mentioned circumstances, and there is no short-circuit failure during pressure crimping of the laminate tape, there is no risk of short-circuit failure due to mechanical stress on the external lead wire, and the drawer The object of the present invention is to obtain a film package type aluminum electrolytic capacitor whose terminal portion can be completely sealed.

[Summary of the invention] The film package type aluminum electrolytic capacitor of the invention consists of a polyester film, aluminum foil, a heat-resistant insulation net, and an ionomer sheet laminated in this order.
The capacitor element is sandwiched between two sheets of laminated tape, with the ionomer sheets facing each other, and the periphery of the capacitor element of the laminated tape is heat-pressed.

[Embodiment of the invention] The film package type aluminum electrolytic capacitor of the invention is packaged using the laminated tape shown in FIGS. 3A and 3B. Figure 3A shows a polyester film 4, aluminum foil 5, heat-resistant insulation mesh 6, and ionomer sheet 7 laminated in this order, and Figure 3B shows a polyester film 4, aluminum foil 5, and an ionomer sheet 7 laminated in this order. A foil 5, an ionomer sheet 7, and a heat-resistant insulating net 6 are laminated in this order. The heat-resistant insulating net 6 is a net or woven fabric made of fibers such as heat-resistant resin and glass.

The capacitor element is packaged in the same manner as shown in FIG. 1, with the non-thermoplastic polyester film 4 placed on the outside. Therefore, the resin will not adhere to the mold during hot press bonding. When packaging the element 2
A recess for accommodating is formed in the laminated tape by pressing, and the shape of this recess is held by aluminum foil 5.

After the capacitor element is impregnated with a paste electrolyte solution, it is placed in the recess, and the ionomer sheet is overlaid with a laminated tape with the same orientation, and the periphery of the capacitor element is sealed by heat and pressure.

Note that the mold for heating and crimping is provided with a recess equal to the thickness of the terminal at a position corresponding to the terminal part, but since there is variation in the distance between the anode and cathode of the terminal,
If heat and pressure bonding is carried out using a mold with a recessed part, there is a risk of pressing too much or creating a gap in the terminal part of the package. Therefore, a recess corresponding to the terminal is not formed in the mold, and a high temperature (approximately 200°C) is placed inside this recess.
A material such as silicone rubber that can maintain flexibility is pasted on the corresponding part of the terminal. If such a mold is used, even if there are variations in the distance between the terminals, excessive pressing or gaps will not occur. Note that silicone rubber may be used for parts other than the terminal corresponding parts.

In the capacitor of the present invention having the above structure, the lead terminal portion is as shown in FIG. That is, the ionomer sheet 7 constituting the laminate tape melts during heat-press bonding, enters the heat-resistant insulating net 6, and becomes integrated therewith. Therefore, even if the heat and pressure bonding is continued, the aluminum foil 5 and the terminal 3 do not come into contact with each other, and there is no need to delicately control the heat and pressure as in the past.

[Effects of the invention] In conventional film package type aluminum electrolytic capacitors, the molten ionomer flows during heat and pressure bonding, so the terminals and aluminum foil are cooled and solidified while remaining close to each other, so the external lead wires are slightly bent. In contrast, in the present invention, there is a heat-resistant insulation network in the solidified ionomer, forming a mixed layer. Therefore, the strength is high and there is no risk of damage even if external force is applied to the external lead wire.

[Brief explanation of the drawing]

Figure 1 is a plan view of part of the manufacturing process of a film package type aluminum electrolytic capacitor, Figure 2 A and B
3A and 3B are perspective views showing two examples of the laminated tape used in the present invention, and FIG. 4 is a sectional view of the main part of one embodiment of the present invention. 1... Laminating tape, 2... Capacitor element,
3...Terminal, 4...Polyester film, 5...Aluminum foil, 6...Heat-resistant insulation net, 7...Ionomer sheet.

Claims (1)

[Scope of utility model registration request] Using two laminate tapes made by laminating polyester film, aluminum foil, heat-resistant insulation net, and ionomer sheet in this order, sandwich the capacitor element with the ionomer sheets facing each other, and heat and press the laminate tape around the capacitor element. A film package type aluminum electrolytic capacitor characterized by: