JP4797812B2 - Manufacturing method of aluminum electrolytic capacitor - Google Patents

Description

  The present invention relates to an electrolytic solution supply method and an aluminum electrolytic capacitor manufacturing method in an aluminum electrolytic capacitor used in various electronic devices and vehicle circuits.

  FIG. 4 is a schematic view of an impregnation apparatus for vacuum impregnating a capacitor element in a conventional aluminum electrolytic capacitor with a separator interposed between an anode foil and a cathode foil. The capacitor element 41 having lead wires connected to the cathode foil and the cathode foil is disposed in a fixing portion 42 provided in the vacuum chamber 48. After the vacuum chamber 48 is evacuated by a vacuum pump 47, the electrolytic solution 44 is applied to the capacitor element 41. It is impregnated.

  The conventional impregnation apparatus configured in this manner opens the valve 45 that opens and closes the vacuum pressure path, depressurizes the inside of the vacuum chamber 48 by the vacuum pump 47, and stores the electrolytic solution 44 after reaching a predetermined vacuum pressure. The tank 43 is directly raised by the driving device, the capacitor element 41 is immersed in the electrolytic solution 44, and the state is maintained for a predetermined time. Subsequently, the impregnation apparatus was configured to open the opening / closing valve 46 in the atmospheric pressure path to return to the atmospheric pressure, lower the storage tank 43, and take out the capacitor element 41 (see Patent Document 1).

In addition, as a method for supplying an electrolytic solution, a method has been proposed in which, after an electrode is accommodated in a can, a predetermined amount of the electrolytic solution is divided and injected by a metering pump (see Patent Document 2).
JP 2003-217991 A Japanese Patent Laid-Open No. 09-050801

  However, since the conventional impregnation apparatus directly receives variations in the drive system that moves the storage tank 43 up and down, the liquid level position during immersion in the capacitor element 41 varies, and if the liquid level position is high, the capacitor element 41 is connected. There has been a problem that the electrolytic solution 44 adheres to the aluminum round bar portion of the lead wire and impregnation is impaired when the liquid surface position is low.

  In addition, since a large number of capacitor elements 41 are immersed at a time, the amount of the electrolyte solution 44 impregnated in the capacitor element 41 cannot be quantified. There was a problem that the consumption of the electrolytic solution 44 increased.

  In addition, in the method of injecting a predetermined amount of the electrolytic solution by dividing it with a metering pump, the electrolytic solution is likely to adhere to the lead wire, and the sealing performance with the sealing body is deteriorated, and the electrolytic solution supply device is large. Therefore, there is a problem that the apparatus becomes expensive. Furthermore, when trying to control the amount of the electrolytic solution to 1 ml or less, there is a problem that it is difficult to obtain an accurate amount due to the presence of bubbles and the like.

  The present invention solves such a conventional problem, suppresses capital investment, can easily supply a predetermined amount of the electrolytic solution reliably, and can also supply a predetermined amount of the electrolytic solution injected into the metal case to the capacitor. An object of the present invention is to provide an electrolytic solution supply method and an aluminum electrolytic capacitor manufacturing method capable of impregnating the element with certainty and reducing variations in characteristics of the aluminum electrolytic capacitor.

Air present invention in order to solve the above problems, arranged a plurality of T-shaped hose to suck the electrolyte solution in the lid portion of the container filled with electrolyte solution, to remove one bubbles electrolyte of the T-shaped hose A storage part is provided with a reservoir part and a reservoir part for stably injecting electrolyte, and the other part of the T -hose and the metering pump are connected by a tube, and the electrolyte is sucked by the metering pump and fixed. A step of injecting an amount of electrolyte into the metal case, a step of inserting a capacitor element having a sealing body attached to an external lead wire into the metal case, and reducing the pressure inside the metal case to thereby add the electrolyte to the capacitor element. The method of manufacturing an aluminum electrolytic capacitor includes a step of impregnating and a step of sealing the opening of the metal case with a sealing body .

  In addition, a filter is disposed at the electrolyte suction port of the T-type hose, and a liquid detection rod for detecting the remaining amount of the electrolyte in the container is further disposed so that the remaining amount of the electrolyte is less than a predetermined amount. In this case, the electrolytic solution supply method is such that the metering pump is stopped by the controller when it becomes.

This onset Ming, with the structure which is disposed a reservoir for the liquid reservoir for injecting stably the air reservoir portion and the electrolyte solution to remove bubbles of the electrolytic solution in one of the T-shaped hose taken together When aspirating from the metering pump, the electrolyte side and the liquid reservoir side are balanced by a T-type hose, so that a small amount (1 ml or less) of the electrolyte can be obtained without any bubbles in the electrolyte. A constant amount can be discharged continuously.

  Moreover, since the structure of the supply device is simple, the equipment cost is low, the failure rate is low, and maintenance is easy.

  In addition, since a certain amount of electrolyte can be injected into the metal case by the method for manufacturing an aluminum electrolytic capacitor of the present invention, variation in capacitor characteristics can be reduced, and high-quality products can be stably produced. be able to.

  In addition, since the driving device is not used, the liquid level position of the electrolytic solution is not controlled, so that the electrolytic solution does not adhere excessively to the lead wire connected to the capacitor element, and the electrolytic solution reaches the inside of the capacitor element. The effect that it can be sufficiently impregnated is obtained.

  FIG. 1 is a conceptual diagram of an electrolytic solution supply apparatus according to an embodiment, FIG. 2 is a perspective view of a lid portion, and FIG. 3 is a sectional view of a filter. In FIG. 1, reference numeral 11 denotes a container filled with an electrolytic solution 12. Reference numeral 13 denotes a lid portion disposed on the top of the container 11, and as shown in FIG. Arranged. Also, a T-type hose 16 is connected to the upper part of the hose 14, one of which is a reservoir 17 for removing mixed air when the electrolyte 12 is replenished, and a reservoir for stably injecting the electrolyte. The storage part 19 which the part 18 united together is connected, and the tube 20 which connected the metering pump 21 which attracts | sucks the electrolyte solution 12 to the other is connected.

  A filter 22 for removing foreign matter mixed in the electrolyte 12 is disposed below the hose 14. For example, as shown in FIG. 3, the filter 22 has a configuration in which the hose 14 is connected to the upper portion of a stainless sintered body 31 by a connecting portion 33 using an O-ring, and foreign matter mixed in the electrolyte 12 is completely removed. Can be removed.

  When the metering pump 21 is controlled by the controller 23, a predetermined amount of the electrolytic solution 12 in the container 11 can be injected into the metal case 24.

  The electrolyte 12 is composed of an organic solvent such as ethylene glycol, γ-butyrolactone, and water, and an electrolyte composed of an organic carboxylic acid such as maleic acid, benzoic acid, and phthalic acid, or an inorganic acid such as boric acid, and has a viscosity of 1 It has a relatively high viscosity of ˜40 mPa · s.

  The viscous electrolyte solution 12 is sucked from the metering pump 21 so that a relatively small amount (0.1 to 1.0 ml) is obtained by the metering pump 21 through the filter 22 and the hose 14 through the T-type hose 16. However, the liquid volume can be easily controlled accurately.

  The hose 14 and the tube 20 preferably have an inner diameter of 10 mm or less in consideration of a small amount of electrolyte solution of 1 ml or less, and the tube has an inner diameter smaller than the inner diameter of the hose. It is difficult to control and a small amount of electrolyte can be accurately controlled.

  When the liquid level of the electrolytic solution 12 reaches the sintered body 31 of the filter 22, it is detected by the liquid level detection rod 15 and the operation of the metering pump 21 is stopped by the controller 23. If the liquid level is lowered to the middle of the sintered body 31 of the filter 22, many bubbles are present in the electrolyte 12, and cannot be removed only by the air reservoir 17, and a predetermined amount of the electrolyte 12 is removed from the metal case 24. Can not be injected into.

  In the metal case 24 injected with the electrolytic solution 12, a capacitor element in which an anode foil and a cathode foil are wound through a separator is inserted, and the inside of the metal case is decompressed to impregnate the capacitor element with the electrolytic solution 12. Then, an electrolytic capacitor can be obtained by sealing the open end of the metal case 24 with a sealing body.

  In this way, by providing a branching portion (T-shaped hose 16) so that the movement path of bubbles caused by suction of the electrolyte and the supply path of the electrolyte are separated in the supply path of the electrolyte, the electrolyte containing no bubbles is metalized. The case 24 can be injected.

  Hereinafter, a specific example will be described.

(Example)
In the electrolytic solution supply apparatus according to the embodiment, an electrolytic solution having the composition (viscosity: 10 mPa · s) shown in the following (Table 1) was filled in a container, and 0.2 ml of the electrolytic solution was injected into the metal case. . The hose 14 had an inner diameter of 6 mm, and the tube had an inner diameter of 3 mm. In addition, 20 metal cases were prepared.

  A capacitor element in which an anode foil and a cathode foil are wound through a separator is inserted into the metal case, and after the pressure inside the metal case is reduced and the capacitor element is impregnated with an electrolytic solution, the open end of the metal case Was sealed with a sealing body to produce an aluminum electrolytic capacitor (rated voltage 16V 100 μF φ8 × 16 mm).

(Comparative example)
In the conventional impregnation apparatus shown in FIG. 4, the electrolytic solution shown in (Table 1) is stored in the storage tank 43 of the impregnation apparatus, and the capacitor element similar to that of the above embodiment is attached to the fixing portion 42 provided in the vacuum tank 48. After the arrangement, the valve 45 for opening and closing the vacuum pressure path is opened, the inside of the vacuum chamber 48 is depressurized by the vacuum pump 47, and after reaching a predetermined vacuum pressure, the storage tank 43 storing the electrolyte is directly raised by the driving device. The capacitor element 41 is immersed in the electrolytic solution, and the state is maintained for a predetermined time. Subsequently, the opening / closing valve 46 of the atmospheric pressure path is opened to return to the atmospheric pressure, the storage tank 43 is lowered, and the capacitor element 41 is taken out. Next, an aluminum electrolytic capacitor was produced in the same manner as in the previous example (rated voltage 16V 100 μF φ8 × 16 mm).

  About 50 pieces of the aluminum electrolytic capacitors of the examples and comparative examples were prepared, and the initial characteristics and life test were conducted at 105 ° C. The results are shown in (Table 2). The value represents an average value of 50 pieces.

  As is apparent from Table 2, the initial characteristics of the aluminum electrolytic capacitors of the examples can obtain a higher value of capacitance than the comparative example, and the capacitance variation is about half or less than that of the comparative example. Can be reduced. In addition, the aluminum electrolytic capacitor of the example did not cause a problem such as liquid leakage or puncture even when a life test at 105 ° C. was performed.

  As described above, bubbles are interposed in the electrolytic solution by maintaining the balance between the electrolytic solution side and the liquid reservoir side by the T-type hose when sucked from the metering pump by the electrolytic solution supply method of the present invention. Therefore, even a very small amount of electrolyte of 0.2 ml can be discharged constantly, so that variations in capacitor characteristics can be reduced, and high-quality products can be stably produced.

  In the method of supplying the electrolytic solution according to the present invention, bubbles of the electrolytic solution can be easily removed, so that a certain amount of electrolytic solution can be injected into the metal case. Further, since the structure of the supply device is simple, the equipment cost is low, the failure rate is low, the maintenance is easy, and it is useful in the field where the liquid quantitative control is necessary.

1 is a schematic view of an electrolytic solution supply apparatus according to an embodiment of the present invention. The perspective view which shows the structure of the cover part Sectional drawing which shows the structure of the filter Schematic of an electrolytic solution impregnation device showing a conventional configuration

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Container 12 Electrolyte 13 Cover part 14 Hose 15 Liquid level detection rod 16 T-type hose 17 Air reservoir 18 Liquid reservoir 19 Storage part 20 Tube 21 Metering pump 22 Filter 23 Controller 24 Metal case 31 Sintered body 33 Connection part

Claims (2)

To place a plurality of T-type hoses for sucking the electrolyte in the lid of the container filled with the electrolyte, and to stably inject the electrolyte into one of the T-type hoses and an air reservoir for removing bubbles of the electrolyte Providing a storage part in which the liquid reservoir part is combined, connecting the other of the T-type hose and the metering pump with a tube, sucking the electrolyte with the metering pump, and injecting a certain amount of electrolyte into the metal case; A step of inserting a capacitor element having a sealing body attached to an external lead wire into the metal case, a step of depressurizing the inside of the metal case to impregnate the capacitor element with an electrolyte, and an opening of the metal case. The manufacturing method of the aluminum electrolytic capacitor provided with the process sealed with a sealing body. The method for producing an aluminum electrolytic capacitor according to claim 1, wherein a filter is disposed at the electrolyte suction part of the T-type hose.

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