JP2011071177A - Aging method of solid electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform aging of a lot of solid electrolytic capacitors at once without limiting the current by connecting individual resistors or constant current diodes in series with respective solid electrolytic capacitors and then applying a DC voltage thereto, in the aging method of solid electrolytic capacitors where a plurality of solid electrolytic capacitors having external terminals on both sides are connected in parallel with two processing electrodes for aging. <P>SOLUTION: In the aging method of solid electrolytic capacitors, the solid electrolytic capacitors are connected between the processing electrodes at least on one side and the external terminals provided on the upper surface thereof through a resistor sheet for aging. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solid electrolytic capacitor aging treatment method. In particular, the present invention relates to an aging treatment method for a chip-type solid electrolytic capacitor.

  The electrolytic capacitor uses an oxide film as a dielectric, and is subjected to an aging treatment in order to repair partial destruction of the dielectric oxide film generated in the manufacturing process. Conventionally, this method has been performed by connecting individual resistors or constant current diodes in series to a plurality of electrolytic capacitors and applying a DC voltage in parallel to limit the current (Patent Document 1).

JP-A-5-21286

A chip-type solid electrolytic capacitor has a solid electrolytic capacitor element or the like mounted on each external electrode on a lead frame made up of a pair of positive and negative external electrodes formed by punching a metal plate. Each element is resin-molded in a cubic shape, and then the individual external electrodes are separated from the lead frame.
Solid electrolytic capacitor elements are generally embedded in one end of an anode lead and mixed with a fine powder with an average particle diameter of about 1 μm of a valve metal such as tantalum, niobium, or aluminum, and a binder such as acrylic resin or camphor. A sponge-like anode sintered body formed by press-pressing and then sintering the powder in vacuum, an anodized film on the sintered body, and a solid electrolyte layer such as manganese dioxide or a conductive polymer And a cathode layer such as a carbon layer and a silver layer are sequentially provided.
This chip-type solid electrolytic capacitor is reduced in size year by year as electronic devices are miniaturized, and it is necessary to age a large amount of the solid electrolytic capacitor at one time. For this reason, there has been a limit in performing each of the solid electrolytic capacitors while limiting the current by connecting individual resistors or constant current diodes in series and applying a DC voltage in parallel. Also, if one of multiple solid electrolytic capacitors connected in parallel is short-circuited without using these resistors or constant current diodes, current will flow into the short-circuited solid electrolytic capacitor, and the voltage will drop overall, resulting in aging. It will be interrupted.

  The problem to be solved is to connect individual resistors or constant current diodes in series to each solid electrolytic capacitor and apply a DC voltage in parallel, without limiting the current, and a large amount of solid electrolytic The point is that the capacitor is aged.

The present invention provides a solid electrolytic capacitor aging treatment method in which a plurality of solid electrolytic capacitors having external terminals are connected in parallel to two treatment electrodes and aged, wherein the treatment electrodes are provided on at least one side and the upper surface thereof. This is an aging treatment method for a solid electrolytic capacitor in which the solid electrolytic capacitor is aged by being connected to an external terminal via a resistor sheet.
In addition, the solid electrolytic capacitor aging method described above, wherein the solid electrolytic capacitor is aged by being connected via a resistor sheet having an electrical resistance value of 1 KΩ · cm to 100 KΩ · cm.

  The aging processing method of the present invention is a low-cost, large-capacity capacitor at a time without applying a DC voltage in parallel by connecting individual resistors or constant-current diodes in series to each capacitor and limiting the current. Has the advantage that it can be aged.

1 schematically shows an aging method for a solid electrolytic capacitor according to an embodiment of the present invention. The preparation method of the aging process of the solid electrolytic capacitor concerning embodiment of this invention is shown typically.

The external terminal described in the present invention refers to a terminal for pulling out the anode part and the cathode part of the solid electrolytic capacitor element having the anode part and the cathode part.
In a chip-type solid electrolytic capacitor, a lead frame composed of a pair of positive and negative external electrodes formed by stamping a metal plate is generally used. Solid electrolytic capacitor elements are mounted on each external electrode, and then each element is covered with a resin mold such as epoxy resin to form a cubic shape, and then each external electrode is removed from the lead frame. Separate. The lead frame can be made of a metal plate such as 42 alloy, copper, copper alloy (copper nickel alloy), or white (silver silver), and 42 alloy or copper alloy is used particularly in terms of weldability and rigidity. . In some cases, the surface mounting surface is provided with a plating layer such as solder plating or tin plating, and in particular, a copper, copper alloy surface such as a multilayer plating of nickel, palladium and gold.

  The processing electrode described in the present invention is an electrode for connecting to an external terminal and performing an aging process. The solid terminals are connected in parallel with the external terminals of the plurality of solid electrolytic capacitors at the same interval as the external terminals of the solid electrolytic capacitors to be aged. As for the shape of the external terminal, it is preferable that the portion in contact with the following resistor sheet is in contact with the surface. Moreover, it is preferable to fix on an insulating substrate so that it may become the same space | interval as between external terminals of the solid electrolytic capacitor to age.

The resistor sheet described in the present invention is a strip-like sheet having resistance, and is provided in a long shape on the surface in the length direction of the processing electrode on at least one side, between the processing electrode and the external terminal provided on the upper surface thereof. Are electrically connected to each other through this resistor sheet.
If the sheet has a uniform resistance, the sheet is thinner than the width, and the electric resistance value is preferably in the range of 1 KΩ · cm to 100 KΩ · cm.
If the electrical resistance value is larger than 100 KΩ · cm, the burden on the power source becomes large and uneconomical.
When the electrical resistance value is as small as 1 KΩ · cm, when a defective capacitor is short-circuited, aging of a good product is likely to be interrupted (by the operation of the power supply protection circuit).
When the thickness is smaller than the width, the current flows preferentially in the thickness direction, and does not easily flow between the capacitors. A sheet having an anisotropic resistance having an electric resistance value in the thickness direction lower than that in the width direction is preferable because current flows more preferentially in the thickness direction and hardly flows between capacitors.

The material of the resistor sheet can be composed of a binder and conductive particles, and a stabilizer, a release agent, a plasticizer, a flame retardant, and the like can be used as necessary.
Here, as the binder, polycarbonate resin, polyarylate resin, polyester resin, polyurethane resin, polyamide resin, polyacetal resin, polyimide resin, polyolefin resin, silicone resin and its copolymer resin polyphenylene oxide and nonyl resin, polysulfone resin, Synthetic resins such as diene polymers and copolymers thereof are preferred, and it is also possible to use a mixture of two or more of these.
Examples of the polyolefin resin and the copolymer resin thereof include polyethylenes such as high density polyethylene, medium, low density polyethylene, and linear low density polyethylene, polypropylenes such as isotactic polypropylene and syndiotactic polypropylene, polybutene, 4 -Methylpentene-1 resin or the like can be used. Also, ethylene-acrylate copolymers such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl acrylate copolymers, Copolymers of olefins and vinyl compounds such as ethylene-vinyl chloride copolymers, fluorine-containing ethylene polymers, and modified products thereof can also be used.
As the polyamide resin, for example, nylon 6, nylon 8, nylon 11, nylon 66, nylon 610 and the like can be used. As the polyester resin, for example, polyethylene terephthalate, polybutylene terephthalate and the like can be used.
As the conductive particles, for example, granular materials such as carbon black particles and graphite particles, powdered materials such as metal powder and metal oxide powder, and fibrous materials such as carbon fiber can be used. As the metal powder, aluminum powder, nickel powder, and as the metal oxide powder, titanium oxide, tin oxide, zinc oxide, ITO (oxide of indium tin alloy) or the like can be used. Among these, granular materials such as carbon black particles and graphite particles, particularly carbon black particles such as acetylene black and ketjen black are preferable. The various conductive particles may be used alone or in combination of two or more. Although there is no restriction | limiting in particular as a particle size of electroconductive particle, For example, an average particle diameter is 10 nm-200 nm normally, Preferably, it is 15 nm-100 nm. When the conductive particles are fibrous, the aspect ratio (length / width length ratio) is usually 1 to 1000, and preferably about 1 to 100.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 schematically shows an aging treatment method for a solid electrolytic capacitor according to an embodiment of the present invention.
1A shows a front view, and FIG. 1B shows a cross-sectional view as seen from the bottom.
Reference numeral 1 denotes a solid electrolytic capacitor, and 2 denotes a pair of external electrodes of the solid electrolytic capacitor 1. Each solid electrolytic capacitor 1 is formed by extending a pair of external electrodes 2 to the left and right and vertically lining up at equal intervals, and is connected to each external electrode 2 formed from a lead frame 8. One external electrode 2 remains connected, and the other external electrode 2 is separated. On the other hand, it is easier to handle if you are connected.
Reference numeral 3 denotes an insulating substrate, and 4 denotes a pair of processing electrodes. The processing electrode 4 has a strip shape, is parallel to the shape of the external electrode 2, and is fixed on the insulating substrate 3 which is an aging processing table.
Reference numeral 5 denotes a resistor sheet, which is provided on the processing electrode 4 in a long shape according to the shape of the processing electrode 4 between the processing electrode 4 and the external electrode 2 on the side where the external electrodes 2 are individually separated. .
Reference numeral 6 denotes a fixing member, which is an insulating member for fixing the external electrode 2 and the processing electrode 4 or the resistor sheet 5 so as to be electrically connected.
In FIG. 1, aging is performed by applying a DC voltage in parallel to the solid electrolytic capacitor 1 between a pair of processing electrodes 4 by a power source 7.

FIG. 2 schematically shows a preparation method for the aging treatment of the solid electrolytic capacitor according to the embodiment of the present invention. 2A shows a solid electrolytic capacitor on the lead frame, FIG. 2B shows an aging treatment table, and FIG. 2C shows a state where the solid electrolytic capacitor is installed on the aging treatment table.
First, as shown in FIG. 2A, an element of a solid electrolytic capacitor is connected to each external electrode 2 on a lead frame 8 comprising a pair of positive and negative external electrodes 2 formed by stamping a metal plate. Next, each element is resin-molded in a cubic shape, and then one of the external electrodes 2 is separated from the lead frame 8 by the cutting portion 9 to separate the external electrodes 2 individually.
Next, as shown in FIG. 2 (b), a pair of processing electrodes 4 are fixed in parallel on the insulating substrate 3 of the aging processing table in accordance with the shape of the external electrodes 2, and the external electrodes 2 are separated individually. The resistor sheet 5 is overlaid on the surface of the processing electrode 4 on the side being processed.
Next, as shown in FIG. 2C, the external electrode 2 and the processing electrode 4 or the external electrode 2 and the resistor sheet 5 of the solid electrolytic capacitor 1 of FIG.
Hereinafter, as shown in FIG. 1, the fixing member 6 is placed on each external electrode 2 and aging is started.

On a lead frame made of 42 alloy, 50 sets of solid electrolytic capacitors were formed, and 200 sets of lead frames with solid electrolytic capacitors were prepared by individually separating the positive electrode external electrodes. Next, a pair of processing electrodes are fixed in parallel to the shape of the external electrode on the insulating substrate of the aging processing table, and an electric resistance value having a thickness of 1 mm and a width of 10 mm is formed on the surface of the processing electrode on the positive electrode side. A resistor sheet of 20 KΩ · cm was stacked for the length of the processing electrode.
Next, the 200 sets of lead frames with solid electrolytic capacitors were set on the processing electrodes, the lead frames were fixed from above with fixing members, and aging was performed by applying 10 V to the processing electrodes with a constant voltage power source.

  DESCRIPTION OF SYMBOLS 1 ... Solid electrolytic capacitor, 2 ... External electrode, 3 ... Insulating substrate, 4 ... Processing electrode, 5 ... Resistor sheet, 6 ... Fixing member, 7 ... Power supply, 8 ... Lead frame, 9 ... Cutting part

Claims (2)

  In the solid electrolytic capacitor aging treatment method, wherein a plurality of solid electrolytic capacitors having external terminals are aged by being connected in parallel to two treatment electrodes, and at least one side of the treatment electrodes and the external terminals provided on the top surface thereof. A solid electrolytic capacitor aging treatment method comprising aging the solid electrolytic capacitor with a resistor sheet interposed therebetween.   2. The solid electrolytic capacitor aging method according to claim 1, wherein the solid electrolytic capacitor is aged by connecting through a resistor sheet having an electric resistance value of 1 KΩ · cm to 100 KΩ · cm.

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