WO2020159062A1 - Method for manufacturing solid electrolytic condenser, and electrolytic solution for solid electrolytic condenser - Google Patents

Abstract

The present invention relates to a method for manufacturing a solid electrolytic condenser, and an electrolytic solution for a solid electrolytic condenser. The method for manufacturing a solid electrolytic condenser, according to the present invention, comprises the steps of: winding an anode foil, a separator and a cathode foil on a cylindrical winding device; impregnating a polymer dispersion solution into the winding device when the winding device is wound; drying the winding device, having been impregnated with the polymer dispersion solution, when the polymer dispersion solution is impregnated into the winding device; impregnating an electrolytic solution into the winding device when the winding device is dried; assembling the winding device on a case when the electrolytic solution is impregnated into the winding device; and performing aging by applying an aging voltage to the winding device assembled on the case, wherein, in the aging step of aging the winding device, the minimum aging voltage at which the aging step starts is different from the maximum aging voltage at which the aging step ends.

Description

Solid electrolytic capacitor manufacturing method and electrolyte for solid electrolytic capacitors

The present invention relates to a method for manufacturing a solid electrolytic capacitor, and in particular, by adding silica gel (SiO ₂ ) to the electrolyte, the voltage is maintained even in an environment in which a Pb free solder is melted at a temperature of 200°C or higher, that is, in a high temperature environment. It relates to a method of manufacturing a solid electrolytic capacitor capable of increasing and reducing leakage current.

The solid electrolytic capacitor is manufactured using a conductive polymer and an electrolyte, and can realize high capacity and high voltage, which are advantages of using the electrolyte, while realizing low impedance characteristics characteristic of the solid electrolyte, and related technology is disclosed in Japanese Patent Publication No. 5879517 Is open.

Japanese Patent Publication No. 5879517 relates to a manufacturing method of an electrolytic capacitor and an electrolytic capacitor, and the manufacturing method of an electrolytic capacitor of Japanese Patent Publication No. 5879517 includes a process of forming a capacitor element and impregnating an electrolytic solution into the capacitor element. do. The process of forming the condenser element forms a condenser element having an anode foil having a dielectric layer on the surface and a solid electrolyte layer in contact with the dielectric layer, and the process of impregnating the electrolytic solution in the condenser element impregnates the condenser element with the electrolyte when the condenser element is formed. As the electrolyte, a first solvent composed of polyethylene glycol having an average molecular weight of 300 to 1000 or a derivative thereof is used.

As in Japanese Patent Registration No. 5879517, in the case of a conventional solid electrolytic capacitor, a withstand voltage may be lowered due to deterioration or crystallization of the electrolyte layer when a Pb free solder having a temperature of 200°C or higher is applied. There is this.

The purpose of the present invention is to solve the above-mentioned problems, by adding silica gel (SiO ₂ ) to the electrolyte solution, the lead-free (Pb free) solder melting temperature at 200 ° C. It is to provide a method of manufacturing a solid electrolytic capacitor capable of increasing and reducing leakage current.

Another object of the present invention is to provide a method for manufacturing a solid electrolytic capacitor capable of improving the ignition voltage characteristics by adding silica gel (SiO ₂ ) to the electrolytic solution even when a solid polymer layer is formed.

Another object of the present invention is to provide a method for manufacturing a solid electrolytic capacitor capable of reducing a leakage current by connecting a lead terminal in a state where an anode foil or a cathode foil is processed in a curved state.

A method for manufacturing a solid electrolytic capacitor according to an aspect of an embodiment of the present invention comprises the steps of winding an anode foil, an electrolytic cell, and a cathode foil into a cylindrical winding element; When the winding element is wound, impregnating the winding element with a polymer dispersion; Drying the winding element impregnated with the polymer dispersion liquid when the winding element is impregnated with the polymer dispersion liquid; When the winding element is dried, impregnating the winding element with an electrolyte; Assembling the coiling element into a case when the coiling element is impregnated with an electrolyte; And aging by applying an aging voltage to the winding element in which the case is assembled. In the aging step of aging the winding element, the minimum aging voltage when the aging step starts and the aging step ends. The maximum aging voltage of is formed differently.

Further, the aging step includes a plurality of sub-aging steps applied sequentially, and the aging voltage applied in any one of the sub-aging steps may be greater than the aging voltage of the subsequent sub-aging step.

In addition, the time performed in the sub-aging step may be the same as each other.

In addition, the magnitude of the aging voltage of any one of the sub-aging steps may be formed in a range of 5% to 90% of the magnitude of the aging voltage of the subsequent sub-aging step.

In addition, the maximum aging voltage may be formed in a range of 60 to 90% of the ignition voltage of the winding element.

Further, the minimum aging voltage may be formed in a range of 5% to 50% of the maximum aging voltage.

In addition, the electrolyte solution includes an organic solvent, a solute, an additive, and silica gel (SiO ₂ ),

The organic solvent comprises ethylene glycol (ethylene glycol) and gamma butyrolactone, the relative weight ratio of the ethylene glycol and the gamma butyrolactone contained in the organic solvent is 5:5 to 6:4 Range.

In addition, as the solute, at least one of an organic-inorganic complex acid salt and an organic acid salt is used, the additive is one or more of a nitro compound and a sugar, and the organic solvent is the total weight of the electrolyte solution for the solid electrolytic capacitor (wt(weight )%) can contain 76 to 95.4wt% sugar.

In addition, the solute contains 3 to 8 wt% per total weight (wt%) of the electrolytic solution for the solid electrolytic capacitor, the solute is used at least one of an organic-inorganic complex salt and an organic acid salt, the organic-inorganic complex salt is Borodisalicylic acid salt is used, and the organic acid salt may be one or more of ammonium phthalate and ammonium azelate.

In addition, the additive contains 1 to 6 wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor, and the additive is one or more of a nitro compound and a sugar, and the nitro compound is P-nitrophenol ( One or more of p-nitro phenol and p-nitro benzoic acid may be used, and mannitol may be used as the sugar.

In addition, the silica gel (SiO ₂ ) may contain 0.6 to 10 wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor.

The electrolyte solution for a solid electrolytic capacitor according to another aspect of the embodiment of the present invention includes an organic solvent, a solute, an additive, and silica gel (SiO ₂ ), and the organic solvent includes ethylene glycol and gammabutyrolactone. ) Is used, 0, the relative weight ratio of the ethylene glycol and the gamma-butyrolactone contained in the organic solvent may be formed in the range of 5:5 to 6:4.

In addition, the electrolyte solution includes an organic solvent, a solute, an additive, and silica gel (SiO ₂ ), and the organic solvent includes ethylene glycol and gamma butyrolactone, and the organic solvent The relative weight ratio of the ethylene glycol and the gamma-butyrolactone included may be formed in the range of 5:5 to 6:4.

In addition, as the solute, at least one of an organic-inorganic complex acid salt and an organic acid salt is used, the additive is one or more of a nitro compound and a sugar, and the organic solvent is the total weight of the electrolyte solution for the solid electrolytic capacitor (wt(weight )%) can contain 76 to 95.4wt% sugar.

In addition, the solute contains 3 to 8 wt% per total weight (wt%) of the electrolytic solution for the solid electrolytic capacitor, the solute is used at least one of an organic-inorganic complex salt and an organic acid salt, the organic-inorganic complex salt is Borodisalicylic acid salt is used, and the organic acid salt may be one or more of ammonium phthalate and ammonium azelate.

In addition, the additive contains 1 to 6 wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor, and the additive is one or more of a nitro compound and a sugar, and the nitro compound is P-nitrophenol ( One or more of p-nitro phenol and p-nitro benzoic acid may be used, and mannitol may be used as the sugar.

In addition, the silica gel (SiO ₂ ) may contain 0.6 to 10 wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor.

The method of manufacturing a solid electrolytic capacitor of the present invention is an environment in which a Pb free solder is melted at a temperature of 200°C or higher by adding silica gel (SiO2) to the electrolyte by adding silica gel (SiO2) to the electrolyte, that is, Even in a high temperature environment, the withstand voltage can be increased and the leakage current can be reduced, and even when a solid polymer layer is formed, silica gel (SiO2) is added to the electrolyte to improve the formation voltage characteristics, and the anode There is an advantage in that the leakage current can be reduced by connecting the lead terminal in a state where the foil or cathode foil is processed in a curved state.

1 is a flow chart showing a method of manufacturing a solid electrolytic capacitor of the present invention.

FIG. 2 is a perspective view of the winding element manufactured in the step of winding the anode foil, electrolytic cell and cathode foil shown in FIG. 1.

3 is an enlarged cross-sectional view of the portion A1 shown in FIG. 2.

4 is a cross-sectional view showing a state in which the winding element shown in FIG. 2 is assembled to a case.

5 to 7 are graphs showing the electrical test results of the solid electrolytic capacitor to which the electrolytic solution of the present invention is applied, respectively.

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the present embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person having the scope of the invention, and the present invention is only defined by the scope of the claims.

Although the first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from another component. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical spirit of the present invention.

The same reference numerals refer to the same components throughout the specification.

Each of the features of the various embodiments of the present invention may be partially or entirely combined or combined with each other, and technically various interlocking and driving may be possible as those skilled in the art can fully understand, and each of the embodiments may be implemented independently of each other. It can also be implemented together in an associative relationship.

On the other hand, the potential effects that can be expected by the technical features of the present invention, which are not specifically mentioned in the specification of the present invention, are treated as described in the present specification, and this embodiment is applied to those skilled in the art. It is provided to describe the present invention more fully, and the contents shown in the drawings may be exaggeratedly expressed as compared to the actual implementation of the invention, and a detailed description of a configuration determined to unnecessarily obscure the subject matter of the present invention Omitted or briefly described.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 to 3, the method of manufacturing the solid electrolytic capacitor of the present invention first wound the anode foil 111, the electrolyte sheet 112, and the cathode foil 113 into a cylindrical winding element 110 (S10).

When the winding element 110 is wound, the winding element 110 is impregnated into the polymer dispersion (S20).

When the winding element 110 is impregnated with the polymer dispersion, the winding element 110 impregnated with the polymer dispersion is dried (S30).

When the winding element 110 is dried, the winding element 110 is impregnated into the electrolyte 10 (S40).

When the winding element 110 is impregnated into the electrolyte 10, the winding element 110 is assembled to the case 120 (S50).

The wound element 110 in which the case 120 is assembled is aged to restore the damaged oxide films 111a and 113a (S60).

The method of manufacturing the solid electrolytic capacitor of the present invention having the above-described configuration will be described in detail as follows.

The method for manufacturing a solid electrolytic capacitor of the present invention, first, as shown in Figures 1 to 3, the anode foil 111, the electrolytic cell 112, and the cathode foil 113 are wound with a cylindrical winding element 110 (S10). In order to wind the anode foil 111, the electrolytic paper 112, and the cathode foil 113 into the cylindrical winding element 110, first, the anode foil 111 and the cathode foil having oxide films 111a and 113a formed on the surfaces, respectively After connecting the extraction electrodes 121 and 122 to 113, an electrolyte 112 is disposed between the anode foil 111 and the cathode foil 113. Here, the thickness T1 of the oxide film 111a formed on the anode foil 111 is formed to be 0.1 nm to 5 μm, and the thickness T2 of the oxide film 113a formed on the cathode foil 113 is 0.1 nm to It is formed to be l0 nm. That is, the thickness T1 of the oxide film 111a formed on the anode foil 111 is formed to be greater than the thickness T2 of the oxide film 113a formed on the cathode foil 113.

As for the lead-out electrodes 121 and 122, the anode foil 111 and the cathode foil 113 are respectively not curved, but after being processed into a curved surface to some extent, the anode foil 111 and cathode foil 113 are respectively cylindrical. By electrically connecting the anode foil 111 and the cathode foil 113 in a curved state that occurs during winding, the adhesion between the lead electrode 121 and the anode foil 111 or the lead electrode 122 and the cathode foil 113 is improved. By improving the ESR (Equivalent Series Resistance) characteristics, leakage current can be reduced. For example, the lead-out electrodes 121 and 122 are processed by bending the one side connected to the anode foil 111 or the cathode foil 113 to bend the same as the bending of the anode foil 111 or the cathode foil 113. Then, by connecting the drawing electrodes 121 and 122 to the anode foil 111 or the cathode foil 113, the anode foil 111 or the cathode foil 113 is wound in a cylindrical shape to be withdrawn from the anode foil 111 or the cathode foil 113. It is possible to improve the adhesion between the electrodes 121, 122.

The extraction electrodes 121 and 122 are in contact with the anode foil 111 and the cathode foil 113, and when the one side connected to the anode foil 111 and the cathode foil 113 are connected in a flat state, the anode foil 111 When the anode foil 111 and the cathode foil 113 are wound in a cylindrical shape, the area in contact with the anode foil 111 or the cathode foil 113 becomes small, and thus, between the anode foil 111 or the cathode foil 113 and the extraction electrodes 121 and 122. The leakage current is reduced by preventing the adhesion from being deteriorated, and the external electrodes 123 and 124 are connected to the extraction electrodes 121 and 122 respectively connected to the anode foil 111 and the cathode foil 113. When the lead-out electrodes 121 and 122 are respectively connected to the anode foil 111 and the cathode foil 113, the electrolytic cell 112 is provided between the anode foil 111 and the cathode foil 113, each of which has oxide films 111a and 113a formed on the surface. After disposing the electrolyte foil 112 between the anode foil 111 and the cathode foil 113, the anode foil 111, the electrolyte foil 112, and the cathode foil 113 are wound with a cylindrical winding element 110. do. The winding element 110 is assembled by winding the anode foil 111, the electrolytic cell 12, and the cathode foil 113, and the assembly of the winding element 110 uses a known winding equipment (not shown).

When the winding element 110 is wound, as shown in FIG. 1, the winding element 110 is impregnated into the polymer dispersion (S20). For example, when the coiling element 110 is wound, the coiling element 110 has a temperature of 20 to 70°C, a vacuum of 500 to 760mmHg, and a high temperature vacuum for 3 to 30 minutes in a polymer impregnation tank (not shown) in which a polymer dispersion is stored. Impregnate under. The polymer dispersion is stored in a polymer force bath, and the polymer dispersion is formed including a solvent and a solute.

That is, the polymer dispersion is formed by mixing one or more of pure (H2O), EG (ethylene glycol), glycol-based solvent, and dispersant, and polyethylene dioxythiophene (PEDOT), and pure (H20) and EG are used as solvents, and PEDOT Is used as the solute of the dispersion.

When the winding element 110 is impregnated with the polymer dispersion, the winding element 110 impregnated with the polymer dispersion is dried as shown in FIG. 1 (S30). The drying method of the winding element 110 impregnated with the polymer dispersion is dried by drying the winding element 110 impregnated with the polymer dispersion in a dryer (not shown) having a temperature of 100 to 200°C for 30 to 150 minutes. ) And the PEDOT layers 111b and 113 are formed on the surfaces of the cathode foil 113, respectively.

When the PEDOT layers 111b and 113 are formed on the surfaces of the anode foil 111 and the cathode foil 113, respectively, as shown in FIG. 1, the surfaces of the anode foil 111 and the cathode foil 113 are respectively PEDOT layers 111b, 113) is impregnated with the wound element 110 is formed in the electrolyte (10) (S40). The impregnation method of the electrolytic solution 10 is an electrolytic solution having a winding element 110 having PEDOT layers 111b and 113 formed on the surfaces of the anode foil 111 and the cathode foil 113, respectively, at a temperature of 20 to 70°C and a vacuum degree of 400 to 740mmHg. Impregnate in an impregnation bath (not shown) for 20 to 150 seconds.

The electrolyte solution 10 is stored in a known electrolyte impregnation tank (not shown), and wound the anode foil 111, the electrolyte sheet 112 and the cathode foil 113, and the anode foil 111 and the cathode foil 113 It is carried out to restore damage to the oxide films 111a and 113a that may be generated in the process of forming the PEDOT layers 111b and 113 on the surface. The impregnated electrolyte solution 10 for restoring the damage of the oxide films 111a and 113a is 76 to 95.4 wt (weight)% of organic solvent, 3 to 8 wt% of solute, 1 to 6 wt% of additive and silica gel (SiO ₂ ) 0.6 To 10 wt%.

As the organic solvent contained in the electrolyte 10, ethylene glycol and gamma butyrolactone are used, and one or more of organic/inorganic complex salts and organic acid salts are used, and the additive is a nitro compound or sugar. One or more are used.

Among the solutes and additives included in the electrolyte solution 10, at least one of organic and inorganic complex salts and organic acid salts is used, and contains 3 to 8 wt% per total weight (wt%) of the electrolyte solution for solid electrolytic capacitors 10 . One or more of organic and inorganic complex salts and organic acid salts are used as the solute.

As the organic-inorganic complex salt used as a solute, a borodisal icylicacid salt is used, and as the organic acid salt, at least one of ammonium phthalate and ammonium azelate is used. When the solute contains 3 wt% per total weight of the electrolyte 10, borodisalicylate 3 wt% is used. When such a solute contains 8 wt% per total weight of the electrolyte 10, 5 wt% of borodisalicylate is used, 1 wt% of phthalate is used, and 2 wt% of azelarate is used.

The additive contains 1 to 6 wt% per total weight (wt%) of the electrolytic solution for solid electrolytic capacitors 10, and at least one of a nitro compound and a sugar is used. One or more of p-nitrophenol and p-nitro benzoic acid is used as the nitro compound, and mannitol is used as the sugar. In the case where 1 wt% per total weight (wt%) of the electrolyte solution 10 is included, P-nitropanel 1 wt% is used, and 6 wt% per total weight (wt%) of the electrolyte solution 10 is included. For 1-% by weight of p-nitrophenol, 4% by weight of p-nitrobenzoic acid is used, and 1% by weight of mannitol is used.

Silica gel (SiO ₂ ) serves as an additive, and by adding silica gel (SiO ₂ ) to the electrolyte solution 10, a polymer layer that is solid in the anode foil 111 or the cathode foil 113, that is, polyethylene dioxythiophene (PEDOT) Even when the layers 111b and 113b are formed, the withstand voltage of the electrolytic solution 10 can be increased, the leakage current can be reduced, and the chemical conversion voltage characteristics can be improved.

Silica gel (SiO ₂ ) contains 0.6 to 10 wt% per total weight (wt%) of the electrolytic solution 10 for a solid electrolytic capacitor.

When the silica gel (SiO ₂ ) is contained less than 0.6wt%, there is a problem that the leakage current is still large due to an insignificant addition effect, and when it contains more than 10wt%, all of the solutes in the electrolytic solution are not soluble in the solvent and some precipitate. Occurs.

When the winding element 110 is impregnated into the electrolyte 10, the winding element 110 is assembled to the case 120 as in FIGS. 1 and 4 (S50). The winding element 110 connects the external electrodes 123 and 124 to the withdrawing electrodes 121 and 122 connected in the curved state generated when the anode foil 111 and the cathode foil 113 are respectively wound in a cylindrical shape before being assembled to the case 120. Connect each. The external electrodes 123 and 124 are respectively connected to the extraction electrodes 121 and 122, and are inserted through the insulating pad 125 so that each part of the external electrodes 123 and 124 is exposed to the outside. That is, in the case 120, as shown in FIG. 4, the take-out electrodes 121 and 122 are disposed inside while the winding element 110 is disposed inside, and one side of each of the external electrodes 123 and 124 connected to each is inside. It is sealed by the insulating pad 125 so that each other side is exposed to the outside in a state arranged in.

When the winding element 110 is assembled to the case 120, as shown in FIG. 1, the wound element 110 assembled with the case 120 is aged to restore damaged oxide films 111a and 113a (S60).

That is, when the winding element 110 is assembled to the case 120, the case 120 is impregnated with the wound element 110 assembled into the electrolyte 10, and then aging treated using an edge treatment device (not shown) to be damaged. By restoring the oxide films 111a and 113a, it is possible to improve product characteristics and product productivity.

Table 1 shows an example of an electrolytic solution 10 to be used for the electrical test of the solid electrolytic capacitor prepared by the method of manufacturing the solid electrolytic capacitor of the present invention described above. Comparative Examples 1 to 3 shown in Table 1, respectively, the silica gel (SiO ₂ ) is not applied to the electrolyte 10, and Examples 1 to 7 are prepared by including the silica gel (SiO ₂ ) in the electrolyte 10, respectively. It is done. However, Comparative Example 4 is a case in which the silica gel (SiO ₂ ) is included in the electrolytic solution 10 in excess of the upper limit.

	Composition unit of electrolyte (wt%)
	Organic solvent		solute			additive			Silica gel
	Ethylene glycol	Gamma-butyrolactone	Organic and inorganic complex salt	Organic acid salt		Nitro compounds		Party
			Borodisalicylate	Phthalic acid	Azelaic acid	P-nitrophenol	P-nitrobenzoic acid	Mannitol
Comparative Example 1	56.0	40	3	-	-	One	-	-	-
Comparative Example 2	38.0	55	-	5	-	-	2	-	-
Comparative Example 3	63.0	23	5	One	2	One	4	One	-
Example 1	55.4	40	3	-	-	One	-	-	0.6
Example 2	37.4	55	-	5	-	-	2	-	0.6
Example 3	62.4	23	5	One	2	One	4	One	0.6
Example 4	53.5	40	3	-	-	One	-	-	2.5
Example 5	35.5	55	-	5	-	-	2	-	2.5
Example 6	60.5	23	5	One	2	One	4	One	2.5
Example 7	53.0	23	5	One	2	One	4	One	10
Comparative Example 4	50.5	23	5	One	2	One	4	One	12.5

When explaining the various embodiments shown in Table 1 in detail, first, the electrolyte 10 according to Comparative Example 1 is used as an organic solvent, 56.0wt% of ethylene glycol and 40w t% of gamma-butyrolactone, and an organic complex salt used as a solute. As borodisalicylate 3 wt% was used, and as a nitro compound used as an additive, 1 wt% of pi-nitrophenol was used.

Electrolytic solution 10 according to Comparative Example 2, as shown in Table 1, 38.0wt% of ethylene glycol and 55wt% of gamma-butyrolactone were used as organic solvents, and 5wt% of phthalate was used as an organic acid salt used as a solute. As a nitro compound used, P-nitrobenzoic acid 2 wt% was used.

Electrolytic solution 10 according to Comparative Example 3, as shown in Table 1, 63.0wt% of ethylene glycol and 23wt% of gamma-butyrolactone are used as organic solvents, and 5wt% of borodisalicylate is used as an organic complex used as a solute. , Phthalate 1wt% and azelarate 2wt% were used as organic acid salts, and 1-wt% of p-nitrophenol and 4wt% of p-nitrobenzoic acid were used as nitro compounds used as additives, and 1wt% of mannitol was used as sugar It was prepared.

Electrolytic solution 10 according to Example 1 is used as an organic solvent, as shown in Table 1, 55.4wt% of ethylene glycol and 40wt% of gamma-butyrolactone, and 3wt% of borodisalicylate is used as an organic complex used as a solute. , As a nitro compound used as an additive, 1 wt% of pi-nitrophenol was used, and 0.6 wt% of silica gel (SiO ₂ ) was used.

Electrolytic solution 10 according to Example 2 is used as an organic solvent, as shown in Table 1, 37.4wt% of ethylene glycol and 55wt% of gamma-butyrolactone, and 5wt% of phthalate was used as an organic acid salt used as a solute. As a nitro compound used, 2 wt% of pi-nitrobenzoic acid was used, and 0.6 wt% of silica gel (SiO ₂ ) was used.

Electrolytic solution 10 according to Example 3 is used as an organic solvent, as shown in Table 1, 62.4wt% of ethylene glycol and 23wt% of gamma-butyrolactone, and 5wt% of borodisalicylate is used as an organic complex used as a solute. , 1 wt% of phthalate and 2 wt% of azelaate were used as organic acid salt, 1 wt% of p-nitrophenol and 4wt% of pi-nitrobenzoic acid were used as nitro compounds used as additives, and 1wt% of mannitol was used as sugar. , Silica gel (SiO ₂ ) 0.6wt% was used was prepared.

Electrolytic solution 10 according to Example 4 is used as an organic solvent, as shown in Table 1, 53.5 wt% of ethylene glycol and 40 wt% of gamma butyrolactone, and 3 wt% of borodisalicylate is used as an organic complex used as a solute. , As a nitro compound used as an additive, 1 wt% of P-nitrophenol was used, and 2.5 wt% of silica gel (SiO2) was used.

As shown in Table 1, the electrolyte solution 10 according to Example 5 used 35.5 wt% of ethylene glycol and 55 wt% of gamma butyrolactone as an organic solvent, and 5 wt% of phthalate was used as an organic acid salt used as a solute. As a nitro compound used, 2 wt% of pi-nitrobenzoic acid was used, 1 wt% of mannitol was used as a sugar, and 2.5 wt% of silica gel (SiO ₂ ) was used.

Electrolytic solution 10 according to Example 6 is used as an organic solvent, as shown in Table 1, 60.5wt% of ethylene glycol and 23wt% of gamma-butyrolactone, and 5wt% of borodisalicylate is used as an organic complex used as a solute. , Phthalate 1wt% and azelarate 2wt% were used as the organic acid salt. As a nitro compound used as an additive, pi-nitrophenol 1wt% and pi-nitrobenzoic acid 4wt% were used, and mannitol 1wt% was used as a sugar. , Silica gel (SiO ₂ ) 2.5wt% was used.

The electrolyte 10 according to Example 7 is used as an organic solvent as shown in Table 1, 53.0wt% of ethylene glycol and 23wt% of gamma butyrolactone, and 5wt% of borodisalicylate is used as an organic complex used as a solute. , Phthalate 1wt% and azelarate 2wt% were used as organic acid salts, and 1-wt% pi-nitrophenol and 4wt% pi-nitrobenzoic acid were used as nitro compounds used as additives, and 1wt% mannitol as sugar. , 10% by weight of silica gel (SiO ₂ ) was used.

As for the electrolyte 10 according to Comparative Example 4, 50.5 wt% of ethylene glycol and 23 wt% of gamma-butyrolactone are used as organic solvents as shown in Table 1, and 5 wt% of borodisalicylate is used as an organic complex salt used as a solute. , 1 wt% of phthalate and 2 wt% of azelaate were used as organic acid salt, 1 wt% of p-nitrophenol and 4wt% of pi-nitrobenzoic acid were used as nitro compounds used as additives, and 1wt% of mannitol was used as sugar. , Silica gel (SiO ₂ ) 12.5wt% was used.

Solid electrolyte capacitors were prepared for electrical testing of the solid electrolyte capacitors to which the electrolytes 10 according to Comparative Examples 1 to 4 and Examples 1 to 7 shown in Table 1 were applied. The manufacturing method of the solid electrolytic capacitors to which the electrolytic solutions 10 according to Comparative Examples 1 to 4 and Examples 1 to 7 were applied is the same as the above-described method, and thus the description is omitted.

Table 2 shows the characteristics of the electrolytic solution 10 prepared according to Comparative Examples 1 to 4 and Examples 1 to 7 and the method described above using the electrolytic solution 10 prepared according to Comparative Examples 1 to 4 and Examples 1 to 7 It is a table showing the results of testing the product characteristics of the solid electrolytic capacitor manufactured.

	Electrolyte characteristics			Product Specifications
	pH	Specific resistance (Ω·㎝)	Mars voltage (V)	Capacity(㎌)(at 120㎐)	Loss(%)(at 120㎐)	ESR(mΩ)(at 100㎑)	Leakage current (㎂)
Comparative Example 1	3.72	944	165	100.2	2.68	16.2	6.1
Comparative Example 2	4.59	356	122	100.3	2.67	16.3	5.9
Comparative Example 3	3.35	1250	182	100.2	2.68	16.4	5.5
Example 1	3.54	943	227	100.1	2.69	16.4	3.3
Example 2	4.59	354	173	100.1	2.70	16.5	3.5
Example 3	3.29	1248	235	100.3	2.69	16.6	3.3
Example 4	3.57	932	273	100.2	2.69	16.5	2.2
Example 5	4.33	353	210	100.3	2.71	16.4	1.8
Example 6	3.28	1253	299	100.0	2.70	16.6	2.0
Example 7	3.5	1325	315	100.2	2.78	16.8	2.3
Comparative Example 4	Precipitation

As shown in Table 2, as a result of testing the properties of the electrolytic solution 10 prepared according to Comparative Examples 1 to 4 and Examples 1 to 7, the pH (potential of hydrogen) of the electrolytic solution 10 was measured from 3.28 to 4.59 as a whole. In particular, the electrolyte solution 10 according to Example 6 was measured to be 3.28, and Comparative Example 2 and Example 2 were respectively measured to be 4.59. The specific resistance of the electrolytic solution 10 was measured from 353 to 1235, in particular Example 5 was measured to be 353 and Example 7 was measured to be 1325.

However, in the electrolytic solution 10 according to Comparative Example 4 in which silica gel was excessively added, a solute was not dissolved in a solvent and a part was precipitated.

The chemical conversion voltage of the electrolytic solution 10 was measured as 165V in Comparative Example 1, as shown in Table 2 and FIG. 5, 227V in Example 1, and 273V in Example 4. That is, as the electrolyte solution 10 reduced the content of ethylene glycol and increased the content of silica gel (SiO ₂ ), the ignition voltage increased as shown in FIG. 5. Here, the electrolyte solution 10 according to Comparative Example 1, Example 1 and Example 4 was prepared to reduce the content of ethylene glycol and increase the content of silica gel (SiO ₂ ), respectively. For example, in Comparative Example 1, Example 1, and Example 4, respectively, as shown in Table 1, 40 wt% of gamma-butyrolactone is used as an organic solvent, and 3 wt of borodisalicylate as an organic complex used as a solute. % Is used, and 1 wt% of P-nitrophenol is used as a nitro compound used as an additive. However, in Comparative Example 1, 56 wt% of ethylene glycol was added as an organic solvent, and in Example 1, 55.4 wt% of ethylene glycol and 0.6 wt% of silica gel (SiO ₂ ) were added, and in Example 4, 53.5 wt% of ethylene glycol and silica The difference is that 2.5 wt% of the gel (SiO ₂ ) is added.

The chemical conversion voltage of the electrolytic solution 10 was measured as 122 V in Comparative Example 2, as shown in Table 2 and FIG. 6, and 354 V in Example 2 and 210 V in Example 5. That is, the electrolyte solution 10 reduced the content of ethylene glycol, and when it contained silica gel (SiO ₂ ), the ignition voltage increased as shown in FIG. 6. Here, in Comparative Example 2, Example 2 and Example 5, respectively, as shown in Table 1, the content of ethylene glycol was reduced and the content of silica gel (SiO ₂ ) was increased. For example, the electrolyte 10 according to Comparative Example 2, Example 2, and Example 5 is 55 wt% of gamma-butyrolactone as an organic solvent as shown in Table 1, and 5 wt of phthalate as an organic acid salt used as a solute. % Was used, and as a nitro compound used as an additive, 2 wt% of p-nitrobenzoic acid was used identically to each other. However, in Comparative Example 2, 38 wt% of ethylene glycol was used as the organic solvent, and in Example 2, 37.4 wt% of ethylene glycol was used as the organic solvent, and 0.6 wt% of silica gel (SiO ₂ ) was used, and Example 5 was an organic solvent. As ethylene glycol 33.5wt% was used and silica gel (SiO ₂ ) 2.5wt% is used to produce a difference.

The chemical conversion voltage of the electrolyte solution 10 was measured as 182V in Comparative Example 2, as shown in Table 2 and FIG. 7, Example 3 was measured at 235V, Example 6 was measured at 299V, and Example 7 was measured at 313V. Became. Here, the electrolytic solution 10 according to Comparative Examples 3, 3, 6 and 7 was prepared to reduce the content of ethylene glycol and increase the content of silica gel (SiO ₂ ). That is, as shown in Table 2 and 7, the electrolyte 10 according to Comparative Example 3, Example 3, Example 6, and Example 7, respectively, is used as an organic solvent, 23 wt% of gamma butyrolactone, and used as a solute As a complex acid salt, 5 wt% of borodisalicylate is used, 1 wt% of phthalate and 2 wt% of azelarate are used as organic acid salt, and nitro compounds used as additives include 1 wt% of pi-nitrophenol and 4wt% of pi-nitrobenzoic acid. It was used, and 1 wt% of mannitol was used as a sugar to prepare the same. However, in Comparative Example 3, 63 wt% of ethylene glycol was used as an organic solvent, and in Example 3, 62.4 wt% of ethylene glycol and 0.6 wt% of silica gel (SiO ₂ ) were used as an organic solvent, and Example 6 As an organic solvent, 60.5 wt% of ethylene glycol and 2.5 wt% of silica gel (SiO ₂ ) were used, and Example 7 was prepared by using 53 wt% of ethylene glycol and 10 wt% of silica gel (SiO ₂ ) as organic solvents. There is a difference.

As shown in Table 2, the product properties of the solid electrolytic capacitors prepared respectively were tested using the electrolytes 10 shown in Comparative Examples 1 to 3 and Examples 1 to 8. The capacities of the solid electrolytic capacitors each manufactured using the electrolytes 10 according to Comparative Examples 1 to 3 and Examples 1 to 8 were measured at 100 to 100.3 μF, and losses were measured at 2.67 to 2.78%, and ESR at 16.2. It was measured to be 16.8 mΩ. A phenomenon in which the solid electrolytic capacitor prepared using the electrolytic solution 10 according to Example 8 precipitated occurred.

The leakage currents of the solid electrolytic capacitors each prepared using the electrolyte 10 according to Comparative Example 1, Example 1 and Example 4 were measured as 6.1 μA in Comparative Example 1, as shown in Table 2 and FIG. Was measured at 3.3 μA, and Example 4 was measured at 2 2 μA. Thus, each of the solid electrolytic capacitors prepared by using the electrolytic solution 10 according to Comparative Example 1, Example 1, and Practical Example 4 reduces the content of ethylene glycol and gamma butyrolactone in the electrolytic solution 10 and reduces silica gel (SiO ₂ It can be seen that as the content of) increases, the leakage current decreases as shown in FIG. 5.

Here, the detailed configuration of the electrolytic solution 10 according to Comparative Example 1, Example 1 and Example 4 is the same as described above, the description thereof will be omitted.

The leakage currents of the solid electrolytic capacitors respectively manufactured using the electrolytes 10 according to Comparative Examples 2, 2, and 5 were measured as 5.9 μA in Comparative Example 2, as shown in Table 2 and FIG. Was measured at 3.5 μA, and Example 5 was measured at 1.8 μA. Thus, each of the solid electrolytic capacitors prepared by using the electrolytic solutions 10 according to Comparative Examples 2, 2, and 5 reduces the content of ethylene glycol in the electrolytic solution 10 and increases the content of silica gel (SiO ₂ ). As shown in Fig. 6, the leakage current decreased. Here, the detailed configuration of the electrolytic solution 10 according to Comparative Example 2, Example 2 and Example 5 is the same as described above, and description thereof will be omitted.

The leakage currents of the solid electrolyte capacitors respectively prepared using the electrolytes 10 according to Comparative Examples 3, 3, 6 and 7 were measured as 5.5 μA in Comparative Example 3 as shown in Table 2 and FIG. 7. , Example 3 was measured at 3.3 μA, Example 6 was measured at 2.0 μA, and Example 7 was measured at 2.3 μA. As described above, the solid electrolytic capacitors respectively manufactured using the electrolytes 10 according to Comparative Examples 3, 3, 6, and 7 reduce the content of ethylene glycol and increase the content of silica gel (SiO ₂ ). The leakage current decreased as in. Here, the detailed configuration of the electrolytic solution 10 according to Comparative Example 3, Example 3, Example 6, and Example 7 is the same as described above, and description thereof will be omitted.

Hereinafter, the aging process step S60 according to embodiments of the present invention will be described in detail.

In the aging treatment step (S60), the wound elements 110 in which the case 120 is assembled are aged to restore the damaged oxide films 111a and 113a (S60). In this embodiment, the aging processing step (S60), a plurality of sub-aging steps are sequentially performed, and the aging voltage (minimum aging voltage) of the first sub-aging step of each sub-aging step is the aging voltage of the last sub-aging step ( Less than the maximum aging voltage). In addition, the maximum aging voltage may be formed in a range of 60 to 90% of the ignition voltage of the winding element, and the minimum aging voltage may be formed in a range of 5% to 50% of the maximum aging voltage. .

In more detail, the aging voltages may be formed differently for each sub-aging step, and the magnitude of the aging voltage in any one of the sub-aging steps is 5% to 5% of the magnitude of the aging voltage in the subsequent sub-aging step. It is formed in the range of 90%.

However, a configuration in which the aging voltages of some sub-aging steps are identically formed may also be included in embodiments of the present invention.

Table 3 shows an embodiment of the aging treatment step (S60) in the method for manufacturing a solid electrolytic capacitor of the present invention described above. Comparative Example 5 shown in Table 1 is applied to the same voltage (e.g., 38V) for a predetermined aging time (e.g. 120 minutes) to the cochle electrolytic capacitor during the aging process, wherein ethylene glycol and gamma-butyrolactone The relative weight ratio of is 3:7, and the applied aging voltage may be set in a range of 60% to 90% of the ignition voltage of the metal foil of the winding element. The aging voltage in Comparative Example 5 is formed at 38V, which is approximately 84% of 45V, which is the image voltage of the metal foil.

In Examples 8 to 10, the voltage was gradually increased from 8V to 38V while the predetermined aging time of the solid electrolytic capacitor was passed through a total of six sub-aging steps of the first sub-aging step to the sixth sub-aging step. It was boosted and approved. At this time, in Examples 8 to 10, the weight ratio of ethylene glycol and gamma butyrolactone in the electrolytic solution of the solid electrolytic capacitor is set differently, and the time of each sub-aging step is exemplarily 20 minutes.

The aging voltage in the first sub-aging step is 8V, the aging voltage in the second sub-aging step is 15V, the aging voltage in the third sub-aging step is 22V, the aging voltage in the fourth sub-aging step is 29V, the fifth The aging voltage in the sub-aging step is 38V, and the aging voltage in the sixth sub-aging step is 38V. The applied voltage in the first sub-aging step may be referred to as a minimum aging voltage, and the applied voltage in the fifth sub-aging step and the sixth sub-aging step may be referred to as a maximum aging voltage. The minimum aging voltage may be set in a range of 5% to 50% of the maximum aging voltage, and the difference in aging voltage between each step may be increased in proportion to each step, or may be increased irrespective of the proportionality rate.

And, the aging temperature may be formed in a range of approximately 50 degrees to 100 degrees, the aging temperature in Comparative Example 5 and Examples 8 to 10 is set to 85 degrees.

	Aging voltage applied	EG: GBL relative weight ratio
Comparative Example 5	Same (38V) (120 minutes)	3: 7
Example 8	Multi-stage (8~38V) (6 steps of 20 minutes, total 120 minutes)	3: 7
Example 9	Multi-stage (8~38V) (6 steps of 20 minutes, total 120 minutes)	5: 5
Example 10	Multi-stage (8~38V) (6 steps of 20 minutes, total 120 minutes)	6: 4
Example 10	Multi-stage (8~38V) (6 steps of 20 minutes, total 120 minutes)	7: 3

In Example 8, the weight ratio of ethylene glycol and gamma butyrolactone in the electrolyte of the solid electrolytic capacitor is set to 3:7, and in Example 9, the weight ratio of ethylene glycol and gamma butyrolactone in the electrolyte of the solid electrolytic capacitor is 5:5. Is set to In addition, in Example 10, the weight ratio of ethylene glycol and gamma butyrolactone in the electrolyte of the solid electrolytic capacitor is set to 6:4, and in Example 11, the weight ratio of ethylene glycol and gamma butyrolactone in the electrolyte of the solid electrolytic capacitor is 7 It is set to :3. Meanwhile, the electrolytes of Examples 8 to 11 include solutes, additives, and silica gel, as in Examples 1 to 7.

	Capacity (㎌)	Loss	L/C(㎂)	ESR(mΩ)
Comparative Example 5	104.8	0.038	2.7	22.2
Example 8	105.5	0.037	2.5	19.5
Example 9	105.7	0.036	2.5	17.9
Example 10	105.8	0.036	2.5	17.8
Example 11	103.4	0.039	2.6	18.6

As shown in Table 4, compared to Comparative Example 5 in which the same voltage was continuously applied during the aging time, the aging voltage was stepped up step by step during the aging time, and the applied Examples 8 to 11 applied capacity, loss, leakage current and It was measured that the ESR properties were relatively excellent. Further, as in Examples 9 and 10, when the weight ratio of the ethylene glycol and gamma-butyrolactone in the electrolytic solution of the solid electrolytic capacitor was 5:5 to 6:4, Comparative Example 5, It was determined that the product characteristics such as ESR were superior to those of Example 8 and Example 11.

That is, in the aging step (S60), the aging voltage is applied differently step by step, and when the weight ratio of ethylene glycol and gamma-butyrolactone in the electrolyte of the solid electrolytic capacitor is 5:5 to 6:4, ESR, leakage current (L /C) and loss was reduced and capacity increased.

On the other hand, in this embodiment, each sub-aging step in the aging step S60 is described as being performed for the same time, but a configuration in which each sub-aging step is performed for different times may also be included in the configuration of this embodiment. For example, the first sub-aging step and the second sub-aging step may be performed for 30 minutes, respectively, and the third sub-aging step to the sixth sub-aging step may be performed for 15 minutes, respectively. In addition, each sub-aging step may be set to two or more.

That is, in the aging treatment step (S60), by applying the aging voltage sequentially from the minimum aging voltage to the maximum aging voltage in order from the minimum aging voltage to the high aging voltage, the damaged oxide film ( 111a, 113a) can be more stably restored and generated.

As described above, the method for manufacturing a solid electrolytic capacitor of the present invention is a voltage withstand even in an environment in which a Pb free solder is melted at a temperature of 200°C or higher by adding silica gel (SiO ₂ ) to the electrolyte, that is, a high temperature environment. Can increase the leakage current, reduce the leakage current, and improve the chemical conversion voltage characteristics by adding silica gel (SiO ₂ ) to the electrolyte even when a solid polymer layer is formed, and the anode foil or cathode foil is curved. Leakage current can be reduced by connecting the withdrawal terminal in the processed state.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and it is possible to carry out various modifications within the scope of the claims and detailed description of the invention and the accompanying drawings. It is natural to fall within the scope of.

Forms for carrying out the invention have been described together in the best mode for carrying out the invention above.

An embodiment according to the present invention relates to a method for manufacturing a solid electrolytic capacitor and an electrolyte for a solid electrolytic capacitor, and has the possibility of repeatability and industrial use in an electrolytic capacitor device or the like.

Claims (17)

1. In the method of manufacturing a solid electrolytic capacitor,

   Winding the anode foil, the electrolytic cell and the cathode foil with a cylindrical winding element;

   When the winding element is wound, impregnating the winding element with a polymer dispersion;

   Drying the winding element impregnated with the polymer dispersion liquid when the winding element is impregnated with the polymer dispersion liquid;

   When the winding element is dried, impregnating the winding element with an electrolyte;

   Assembling the coiling element into a case when the coiling element is impregnated with an electrolyte; And

   Including the aging by applying an aging voltage to the winding element is assembled to the case;

   In the aging step of aging the winding element, the method of manufacturing a solid electrolytic capacitor, characterized in that the minimum aging voltage when the aging step starts and the maximum aging voltage when the aging step ends.
2. According to claim 1,

   The aging step,

   It includes a plurality of sub-aging steps applied sequentially,

   The aging voltage applied in any one of the sub-aging step, the method of manufacturing a nose body electrolytic capacitor, characterized in that greater than the aging voltage of the subsequent sub-aging step.
3. According to claim 2,

   A method of manufacturing a solid electrolytic capacitor characterized in that the sub-aging steps are performed at the same time.
4. According to claim 2,

   A method of manufacturing a solid electrolytic capacitor, wherein the magnitude of the aging voltage of any one of the sub-aging steps is formed in a range of 5% to 90% of the magnitude of the aging voltage of the subsequent sub-aging step.
5. According to claim 1,

   The maximum aging voltage, solid electrolytic capacitor manufacturing method characterized in that formed in the range of 60 to 90% of the ignition voltage of the winding element.
6. The method of claim 5,

   The minimum aging voltage, solid electrolytic capacitor manufacturing method characterized in that formed in the range of 5% to 50% of the maximum aging voltage.
7. According to claim 1,

   The electrolyte,

   Contains organic solvents, solutes, additives and silica gel (SiO ₂ ),

   The organic solvent includes ethylene glycol (ethylene glycol) and gamma butyrolactone (gamma butyrolactone),

   The relative weight ratio of the ethylene glycol and the gamma-butyrolactone contained in the organic solvent is a method of manufacturing a solid electrolytic capacitor, characterized in that formed in the range of 5:5 to 6:4.
8. The method of claim 7,

   As the solute, at least one of an organic-inorganic complex acid salt and an organic acid salt is used,

   As the additive, at least one of a nitro compound and a sugar is used,

   The organic solvent is a solid electrolytic capacitor manufacturing method containing 76 to 95.4wt% per total weight (wt (weight)%) of the electrolyte for the solid electrolytic capacitor.
9. The method of claim 7,

   The solute contains 3 to 8 wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor,

   As the solute, at least one of an organic-inorganic complex acid salt and an organic acid salt is used, and the organic-inorganic complex acid salt is used as a borodisalicylic acid salt, and the organic acid salt is ammonium phthalate and ammonium azelate. ) Is a method of manufacturing a solid electrolytic capacitor is used.
10. The method of claim 7,

    The additive contains 1 to 6wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor,

    As the additive, at least one of a nitro compound and a sugar is used, and the nitro compound is at least one of p-nitro phenol and p-nitro benzoic acid, and the sugar is mannitol. A method for preparing a solid electrolytic capacitor in which (mannitol) is used.
11. The method of claim 7,

    The silica gel (SiO ₂ ) is a method for producing a solid electrolytic capacitor containing 0.6 to 10 wt% per total weight (wt%) of the electrolytic solution for the solid electrolytic capacitor.
12. In the electrolytic solution for a solid electrolytic capacitor,

    Contains organic solvents, solutes, additives and silica gel (SiO ₂ ),

    The organic solvent is one or more of ethylene glycol (ethylene glycol) and gamma butyrolactone (gammabutyrolactone) is used,

    The relative weight ratio of the ethylene glycol and the gamma-butyrolactone contained in the organic solvent is an electrolyte solution for a solid electrolytic capacitor, characterized in that formed in a range of 5:5 to 6:4.
13. The method of claim 12,

    The electrolyte,

    Contains organic solvents, solutes, additives and silica gel (SiO ₂ ),

    The organic solvent includes ethylene glycol (ethylene glycol) and gamma butyrolactone (gamma butyrolactone),

    The relative weight ratio of the ethylene glycol and the gamma-butyrolactone contained in the organic solvent is an electrolyte solution for a solid electrolytic capacitor, characterized in that formed in a range of 5:5 to 6:4.
14. The method of claim 12,

    As the solute, at least one of an organic-inorganic complex acid salt and an organic acid salt is used,

    As the additive, at least one of a nitro compound and a sugar is used,

    The organic solvent is a solid electrolytic capacitor electrolyte containing 76 to 95.4 wt% per total weight (wt (weight)%) of the electrolyte for the solid electrolytic capacitor.
15. The method of claim 12,

    The solute contains 3 to 8 wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor,

    As the solute, at least one of an organic-inorganic complex acid salt and an organic acid salt is used, and the organic-inorganic complex acid salt is used as a borodisalicylic acid salt, and the organic acid salt is ammonium phthalate and ammonium azelate. ) Is an electrolyte for solid electrolytic capacitors.
16. According to claim 2,

    The additive contains 1 to 6wt% per total weight (wt%) of the electrolyte solution for the solid electrolytic capacitor,

    As the additive, at least one of a nitro compound and a sugar is used, and the nitro compound is at least one of p-nitro phenol and p-nitro benzoic acid, and the sugar is mannitol. Electrolyte for solid electrolytic capacitors where (mannitol) is used.
17. The method of claim 12,

    The silica gel (SiO ₂ ) is a solid electrolyte electrolytic solution containing 0.6 to 10 wt% per total weight (wt%) of the electrolytic solution for the solid electrolytic capacitor.

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