JP2008130782A - Method for manufacturing lead wire for capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a lead wire for a capacitor, capable of preventing the generation of a whisker in a welding part between a CP wire and an aluminum wire. <P>SOLUTION: The lead wire 1o for the capacitor is obtained by performing the method comprising: a process for welding the CP wire 10 and the aluminum wire 11, so as to form the lead wire 1o for the capacitor, subsequently washing the lead wire 1o for the capacitor with an alkaline washing liquid, and then, removing the alkaline washing liquid; a process for heating the lead wire 1o for the capacitor before/after the washing and washing liquid removing process; a process for heating the lead wire 1o for the capacitor at high temperature under the filling of inert gas; and a process for coating a thermosetting resin on the welding part 12 between the CP wire 10 and the aluminum wire 11, so as to form a resin layer 13, after the above processes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a capacitor lead wire, and more particularly to a method for manufacturing a capacitor lead wire that prevents whisker from occurring in a welded portion where a CP wire and an aluminum wire are welded.

  FIG. 3 is a side view of the main part showing a state where whiskers are generated in the welded portion of the capacitor lead wire. 2. Description of the Related Art Conventionally, a capacitor lead wire 101 in which a CP wire 110 plated with extremely high purity tin and an aluminum wire 111 are welded is known.

  In such a capacitor lead wire 101, tin is exposed to the weld 112 during welding, and a fibrous crystal (hereinafter referred to as whisker) 113 having a thickness of several micrometers is generated from the surface of the metal crystal. grow up. Currently, due to miniaturization of electrical products, the space between components on a printed circuit board is narrowed, and there is a possibility that a short accident may occur due to the growth of the whisker 113. Therefore, conventionally, lead was added during tin plating to prevent the whisker 113 from being generated. In addition to the tin plating, the CP wire includes silver or gold plating, and those made of these metals may cause whiskers.

  At present, however, there is an interest in environmental issues, and plans for restricting or eliminating the use of lead have become a hot topic. Under the Home Appliance Recycling Law enacted in the year 2001, it is mandatory to collect lead. For this reason, as an environmental measure, there is an urgent need to take measures against whiskers generated from the welded portion of the lead wire for capacitors because lead cannot be used. As another method for preventing the occurrence of whiskers, a method of covering a lead wire with a bismuth tin layer has been proposed. However, a bismuth tin-plated lead wire is not a general-purpose CP wire and has a drawback that it is difficult to use. (For example, refer to Patent Document 1).

JP 2000-012386 (full description, full drawing)

  The present invention has been made in view of the above-mentioned problems. When manufacturing a capacitor lead wire, a capacitor lead wire is manufactured using a CP wire plated with tin, silver or gold and an aluminum wire. An object of the present invention is to provide a method of manufacturing a lead wire for a capacitor capable of preventing the occurrence of whiskers in a welded portion between a CP wire and an aluminum wire.

The present invention employs the following means in order to solve the above problems.
The invention according to claim 1 is a method for manufacturing a capacitor lead wire, wherein a welding step of welding a CP wire and an aluminum wire to form a capacitor lead wire, and after the welding step, the capacitor lead wire is A cleaning process for cleaning with an alkaline cleaning liquid, a cleaning liquid removing process for removing the alkaline cleaning liquid following the cleaning process, a heat treatment process for heating the lead wire for the capacitor at a high temperature either before or after the cleaning and the cleaning liquid removing process, The capacitor lead wire is transported into a vacuum heat treatment apparatus, the inside of the vacuum heat treatment apparatus is evacuated, and then the inert gas is filled in the vacuum heat treatment apparatus, and then the capacitor lead wire And a vacuum heat treatment step of heating the substrate at a high temperature.

  According to a second aspect of the present invention, there is provided a method for manufacturing a capacitor lead wire, comprising: a welding step of welding a CP wire and an aluminum wire to form a capacitor lead wire; and the capacitor lead wire after the welding step. A cleaning process for cleaning with an alkaline cleaning liquid; a cleaning liquid removing process for removing the alkaline cleaning liquid following the cleaning process; a heat treatment process for heating the capacitor lead wire at a high temperature either before or after the cleaning and cleaning liquid removing process; The capacitor lead wire is transported into a vacuum heat treatment apparatus, the inside of the vacuum heat treatment apparatus is evacuated, and then the inert gas is filled in the vacuum heat treatment apparatus, and then the capacitor lead wire After the vacuum heat treatment step for heating the wire at a high temperature and after each of the above steps, a thermosetting resin is applied to the welded portion of the CP wire and the aluminum wire. A method of manufacturing the capacitor lead wire, which comprises a coating step of attaching. The CP wire is a copper-clad steel wire, but there are those plated with tin, gold, silver or the like, and the CP wire includes these. The resin applied or coated by the coating step preferably has electrical insulation.

  The invention according to claim 3 is the method for producing a lead wire for a capacitor according to claim 1 or 2, wherein the cleaning step is a step of cleaning at a temperature of 90 ° C to 99 ° C for 10 to 14 minutes, and the heating The treatment step is a step of heating at a temperature of 150 ± 20 ° C. for 18 to 24 minutes, and the heating in the vacuum heat treatment step is performed at a temperature of 180 to 200 ° C. for about 60 minutes. It is a manufacturing method of a lead wire.

  According to the first aspect of the invention, the internal stress of the welded portion of the capacitor lead wire can be relieved by the step of performing a high-temperature heat treatment by filling the inert gas in a vacuum state, and the whisker is welded to the welded portion. Can be prevented. This is considered to be due to the effect of heat diffusion of the inert gas to the lead wire surface layer by preventing metal oxidation of the capacitor lead wire surface by heating at a high temperature in a state filled with an inert gas. Through this process, an aluminum electrolytic capacitor can be mounted on a printed circuit board to withstand an aging process such as product reliability testing, and the reliability of the product that incorporates the component is improved. Can be made.

  According to the second aspect of the present invention, after the step of the method for manufacturing the capacitor lead wire according to the first aspect, the whisker is provided over a longer period of time by applying or adhering a thermosetting resin to the welded portion. It can prevent generating in a welding part.

  Further, according to the invention of claim 3, by setting such temperature and time, it is possible to more effectively prevent the occurrence of whiskers in the welded portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view of an essential part of a capacitor lead wire, and FIG. 2 is a schematic process diagram showing an example of a lead wire manufacturing apparatus. 1 (a) is an extremely high purity tin plated CP lines (copper base tin Hikigane line) 10 and the aluminum wire 11 and the lead wires 1 ₀ capacitor connected in weld 12, FIG. 1 ( b) is a capacitor lead wire 1 in which a resin layer 13 is applied and formed on the welded portion 12 in order to prevent the occurrence of whiskers according to this embodiment. In addition, although the thing which plated high purity gold | metal | money or silver in addition to tin is used for the CP wire 10, this embodiment demonstrates the case where the CP wire 10 is plated with tin.

  A method of manufacturing a capacitor lead wire according to this embodiment will be described with reference to the lead wire manufacturing apparatus 2 shown in FIG. The lead wire manufacturing apparatus 2 includes a cleaning device 20, a liquid recovery device 21, a water washing device 22, a centrifuge 23, an air blow 24, a drying or heat treatment device 25, a cooling device 26, and a transport device 27. The vacuum heat treatment device 30 and the resin coating device 28 are sequentially arranged, and the vacuum heat treatment device 30 is connected with a vacuum pump 31 and an inert gas cylinder 32.

Cleaning device 20, for example, aluminum and non-etching weakly alkaline cleaner (trade name: Fine Cleaner 315) for the alloy by the cleaning liquid such as a cleaning tank for cleaning the leads 1 ₀ capacitor. The cleaning device 20, about 12 minutes leads _{1 0} capacitor with a washing liquid temperature 90 ° C~99 ° C (12 ± 2 min) and washed, or degreased aluminum wire 11, the copper wire 10 and the aluminum Carbon generated when the wire 11 is welded is removed.

Liquid recovery device 21 is a device for collecting the washing liquid adhered to the lead wire 1 ₀ capacitors, by blowing air to the lead wire 1 ₀ capacitors, to recover the cleaning liquid blown from the lead wire 1 ₀ for the capacitor . Also, the water washing device 22 is a device for washing away the cleaning liquid adhering to the lead wire 1 ₀ capacitors, and first deionized water rinse tank 22a, a second deionized water rinse tank 22b, and a pure water shower vessel 22c, pure And a water tank 22d.

Centrifuge 23 utilizes the centrifugal force, a device for removing pure water attached to the lead wire 1 ₀ capacitor, air blow 24, by blowing air to the lead wire 1 ₀ capacitors, for the capacitor a device for blowing off the pure water attached to the lead wire 1 _0.

Heat treatment apparatus 25, as well as dried by heating lead wire 1 ₀ capacitor is a device to prevent the whiskers generated in the welded portion 12. The heat treatment apparatus 25, whisker approximately 21 minutes at a temperature of about 150 ° leads _{1 0} capacitor in order to prevent the occurrence in the weld 12 (150 ± 20 ℃) ( 21 ± 3 minutes) heating To do.

The cooling device 26 is a device that cools the capacitor lead wire 10 heated in the heat treatment device 25. Conveying device 27 is a belt conveyor which circulates drives the transport unit 27a for mounting the lead wire 1 ₀ capacitor.
The cooled capacitor lead wire 10 is carried out in the direction C from the carry-out port 29 of the carrying device 27.

The capacitor lead wire 10 carried out is carried into the vacuum heat treatment apparatus 30. The vacuum heat treatment apparatus 30 is connected to a vacuum pump 31 for making the inside vacuum, and an inert gas cylinder 32 for filling the inside with an inert gas (for example, N ₂ ), and a capacitor lead wire inside. 1 ₀ by the housing, once inside the vacuum state, and further filled with an inert gas, a device capable of heating the lead wire 1 ₀ capacitors therein.

Resin coating device 28 is a device for applying a resin adhesive to weld 12 of the capacitor lead wire 1 ₀ is unloaded after being processed by the vacuum heating treatment apparatus 30. The resin coating device 28 applies a solution of a thermosetting resin adhesive to the welded portion 12 with a roller or a brush, or sprays a resin solution in which the thermosetting resin adhesive is dissolved, thereby welding the welded portion. 12 is a device for applying the resin layer 13 to the resin 12. As a thermosetting resin adhesive, various things, such as an epoxy resin, a phenol resin, a polyurethane, a melamine resin, a urea resin, an unsaturated polyester resin, can be used, for example. In addition, what has electrical insulation is preferable. Through these steps, the resin layer 13 is formed on the welded portion 12, whereby the capacitor lead wire 1 in which no whisker is generated in the welded portion 12 can be manufactured.

Next, a method for manufacturing a capacitor lead wire according to an embodiment of the present invention will be described. CP wire 11 and the aluminum wire 12 and the lead wires 1 ₀ capacitors which are welded, as shown in FIG. 2, when it is placed is carried from drawing A direction in the transport unit 27a, the transport device 27 The transport unit 27a is transported in the direction B in the drawing. Leads 1 ₀ capacitors, are cleaned in the cleaning device 20, together with the aluminum wire 11 is degreased, carbon is removed which occurs when welding the CP line 10 and the aluminum wire 11 (cleaning step) . Then, the lead wire 1 ₀ capacitor is blown air in the liquid recovery device inside 21, the cleaning liquid is washed away in the washing apparatus within 22 (washing solution removing process). Then, the lead wire 1 ₀ capacitor, after pure water was removed by a centrifugal separator 23, the pure water is removed by air blow 24. Then, the lead wire 1 ₀ capacitor is heated and dried by the heating processing apparatus 25.

Heating dried leads 1 ₀ capacitor was is cooled is fed to the cooling device 26 by the transport device 27, it is carried out from the carry-out port 29 to the C direction.
Carried-out lead wire 1 ₀ capacitor was, once a predetermined amount from being pooled, loaded into the vacuum heat treatment apparatus 30, is high temperature heating in the inert gas filling pressure.
Predetermined time heated leads 1 ₀ capacitor was either directly be unloaded as components, or be conveyed to a resin coating device 28, a thermosetting resin is applied to the welded portion 12 of the CP line 10 and the aluminum wire 11 The resin layer 13 is formed on the welded portion 12, and both are carried out as the capacitor lead wire 1 subjected to the whisker generation prevention treatment.

In the embodiment of the capacitor lead manufacturing method described above, the heat treatment step by the heat treatment device 25 is performed after the cleaning step by the water washing device 22 following the cleaning step by the cleaning device 20, but this without being limited to the embodiments, the heat treatment apparatus by integrating a CP line 10 and the aluminum wire 11 and the lead wires 1 ₀ capacitor with a welded, approximately 21 minutes at a temperature 150 ℃ (150 ± 20 ℃) ( After heating for 21 ± 3 minutes), as shown in FIG. 2, the cleaning device 20, the liquid recovery device 21, the water washing device 22, the centrifuge 23, and the air blower 24 are sequentially conveyed, and the cooling device 26 is conveyed in this order Subsequently, the vacuum heat treatment apparatus 30 and the resin coating apparatus 28 may be sequentially manufactured.
In this case, the drying or heat treatment apparatus 25 is a process mainly for drying, and may be heated at a temperature of 150 ° C. (150 ± 20 ° C.) for about 10 minutes (10 ± 4 minutes).

  Furthermore, as other embodiment of this invention, the resin layer 13 of FIG.1 (b) penetrates the cap-shaped resin by a thermosetting resin from the CP wire 10 side, coat | covers the welding part 12, and heats it. In this case, the resin layer 13 may be formed by being melted and gradually cured so that the cap-shaped resin is adhered to the welded portion 12. The cap-shaped resin has a hole formed in the center of the bowl-shaped resin. The CP wire 10 is inserted into the hole, and the welded part 12 is covered and adhered to the upper part of the bowl. May be covered with the resin layer 13. Of course, the shape which coat | covered the welding part 12 is bowl-shaped, and you may coat | cover and cover the welding part 12 with sheet-like resin. In this case, a resin coating device is used instead of the resin coating device 28.

In the above embodiment, the case of the tin-plated CP wire 10 has been described. However, the CP wire 10 also uses a CP wire plated with high-purity gold or silver. There is a possibility that but produced by coating the thermosetting resin to the weld 12 and the high-temperature heat treatment under inert gas of the above embodiment similarly to the read capacitor wire 1 _0, it is possible to prevent the occurrence of whiskers .

As described above, the manufacturing method of a capacitor lead wire of the present invention, the lead wire 1 ₀ capacitor washed with an alkaline washing solution, after removing the washing solution from the capacitor lead wire 1 _0, leads for the capacitor 1 ₀ or heat treatment, or heat treatment before the washing of the lead wire 1 ₀ capacitors, and, by heating the lead wire 1 ₀ capacitors in an inert gas filled in the vacuum heating processing apparatus 30 It is possible to prevent whiskers from occurring in the welded portion 12, and furthermore, by applying a thermosetting resin to the welded portion 12, it is possible to prevent whiskers from being generated in the welded portion 12 over a long period of time.

  The heat treatment temperature is about 150 ° C. (150 ± 20 ° C.) and the heat treatment time is about 21 minutes (21 ± 3 minutes). The heat temperature in the vacuum heat treatment is about 180 ° C. (180 to 200 ° C.). The heating time is about 50 to 70 minutes. There is an advantage that whisker is prevented from being generated by such heat treatment and vacuum heat treatment, and the thermosetting resin layer 13 covering the welded portion 12, and the reliability as a terminal of the aluminum electrolytic capacitor can be improved. .

The present invention is not limited to the embodiment described above, and various modifications or changes are possible, and the following matters are also within the scope of the present invention. For example, in embodiments of the present invention, although heating to about 21 minutes leads 1 ₀ capacitors at a temperature 0.99 ° C., the heating temperature may be within the range of 0.99 ± 20 ° C., the heat treatment time is 21 If it is within a range of ± 3 minutes, it is allowed, and if it is in a low temperature range of 100 ° C. to 125 ° C., it may be heated for about 4 ± 0.5 hours.

Then, the vacuum heat treatment, although heating at about 60 minutes inert gas filling under the lead wire 1 ₀ capacitors at a temperature 180 ° C., the heating temperature is greater than preferably from 180 ℃ ~200 ℃ (240 ℃ Therefore, the heating time is allowed to be within a range of 50 minutes to 80 minutes.

  Also, the resin layer is applied by various methods as described above. For example, when using a brush, the resin is applied to the welded portion 12 by fixing the brush and rotating the capacitor lead wire. Alternatively, conversely, the capacitor lead wire may be fixed and the brush may be moved for application, or various methods may be implemented in which the cap-shaped resin is melt-cured and adhered.

  As an application example of the present invention, there is a lead wire for a capacitor in which generation of whiskers is prevented in a welded portion between a CP wire and an aluminum wire, and can be mainly used as a lead wire of an aluminum electrolytic capacitor.

(A) is the principal part side view of the lead wire for capacitors after welding, (b) is the principal part side view of the lead wire for capacitors by this invention which adhered the resin layer to the welding part. It is the schematic which shows an example of the lead wire manufacturing apparatus for enforcing the manufacturing method of the lead wire for capacitors of this invention. It is a principal part side view which shows the state which the whisker generate | occur | produced in the welding part of the lead wire for capacitors.

Explanation of symbols

1 _0, 1 capacitor lead wire 2 Lead wire manufacturing apparatus 10 CP wire 11 of aluminum wire 12 welded portion 13 resin layer 20 cleaning device 21 liquid recovery device 22 water washing device 23 centrifugal separator 24 air blow 25 drying or heat treatment apparatus 26 cooling device 27 Conveying device 28 Resin coating device (resin coating device)
30 Vacuum heat treatment device 31 Vacuum pump 32 Inert gas cylinder

Claims (3)

In the method of manufacturing a capacitor lead wire,
Welding process of forming a lead wire for a capacitor by welding a CP wire and an aluminum wire;
After the welding step, a cleaning step of cleaning the capacitor lead wire with an alkaline cleaning solution;
A cleaning solution removing step for removing the alkaline cleaning solution following the cleaning step;
A heat treatment step of heating the capacitor lead wire at a high temperature either before or after the cleaning and cleaning liquid removal step;
The capacitor lead wire is conveyed into a vacuum heat treatment apparatus, and the vacuum heat treatment apparatus is evacuated, and then the vacuum heat treatment apparatus is filled with an inert gas, followed by the capacitor lead wire. A vacuum heat treatment process for heating at a high temperature;
The manufacturing method of the lead wire for capacitors characterized by including these. In the method of manufacturing a capacitor lead wire,
Welding process of forming a lead wire for a capacitor by welding a CP wire and an aluminum wire;
After the welding step, a cleaning step of cleaning the capacitor lead wire with an alkaline cleaning solution;
A cleaning solution removing step for removing the alkaline cleaning solution following the cleaning step;
A heat treatment step of heating the capacitor lead wire at a high temperature either before or after the cleaning and cleaning liquid removal step;
The capacitor lead wire is conveyed into a vacuum heat treatment apparatus, and the vacuum heat treatment apparatus is evacuated, and then the vacuum heat treatment apparatus is filled with an inert gas, followed by the capacitor lead wire. A vacuum heat treatment process for heating at a high temperature;
After the said process, the manufacturing method of the lead wire for capacitors characterized by including the coating process which apply | coats or adheres a thermosetting resin to the welding part of the said CP wire and an aluminum wire   The washing step is a step of washing at a temperature of 90 ° C. to 99 ° C. for 10 to 14 minutes, and the heat treatment step is a step of heating at a temperature of 150 ± 20 ° C. for 18 to 24 minutes, and in the vacuum heat treatment step The method for producing a lead wire for a capacitor according to claim 1, wherein the heating is performed at a temperature of 180 to 200 ° C. for about 60 minutes.

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