Improved Forming Electrolyte for Tantalum Solid Electrolytic Capacitors

Abstract

The present invention provides an improved forming electrolyte suitable for forming oxides on a valve metal anode, and an improved capacitor containing the oxide formed in the forming electrolyte. The forming electrolyte comprises an inositol derivative defined by Formula 1. TIFF2026511219000017.tif4554 formula 1 During the ceremony, R 1 ~R 6 These are each defined accordingly.

Description

[Technical Field]

[0001] The present invention relates to an electrolyte for improved formation (anodizing) and for forming a tantalum oxide dielectric on a tantalum anode. More specifically, the present invention is specialized in a formation electrolyte comprising an inositol-derived compound that significantly improves oxide formation. [Background technology]

[0002] Solid electrolytic capacitors, which include sintered tantalum as the anode and oxide formed on a conductive polymer as the cathode, are now widely used throughout the field of electronics in virtually all applications requiring capacitive coupling in electronic assemblies. As will be fully understood by those skilled in the art, tantalum oxide is formed on the tantalum surface and acts as a dielectric between the tantalum anode and the conductive polymer cathode. The process of forming tantalum oxide by exposing the anode to a voltage in the presence of an electrolyte is called anodizing.

[0003] Dielectric quality is a measure of the electrical characteristics of a solid electrolytic capacitor. Poor dielectric quality can lead to component failure. One factor that leads to poor electrical characteristics is abnormal charge current (ACC). Components formed in currently available anodized electrolytes exhibit high ACC, and high ACC is now known to be detrimental to the quality of electrolyte capacitors. This has led to significant efforts to improve the formation or anodizing of electrolytes to provide more stable dielectrics and, as a result, to provide improved solid electrolytic capacitors with lower ACC.

[0004] Solid electrolytic capacitors that use valve metal, specifically tantalum, as the anode and conductive polymer as the cathode exhibit an abnormal charge current (ACC) that exceeds the theoretical value I(t) calculated by {I(t)=C*dv / dt, where C is capacitance and dV / dt is voltage ramp}. ACC can interfere with circuit performance and lead to capacitor failure, as described in Y. Freeman and P. Lessner, *Evolution of Polymer Tantalum Capacitors*, Appl. Sci. 2021, 11(12), 5514-5521. [Overview of the project] [Problems that the invention aims to solve]

[0005] This specification provides an improved electrolyte particularly suitable for use in forming tantalum oxide on tantalum, wherein the tantalum oxide functions as an improved dielectric in a solid electrolytic capacitor.

[0006] The present invention relates to an improved forming electrolyte particularly suitable for use in forming tantalum oxide on tantalum.

[0007] More specifically, the present invention relates to an improved capacitor with enhanced electrical properties, comprising a tantalum anode and a conductive polymer cathode, with an improved tantalum oxide dielectric between them.

[0008] A special feature of the present invention is its ability to form a dielectric oxide on a tantalum anode without changing the manufacturing steps, equipment, or procedures. [Means for solving the problem]

[0009] These and other effects are provided, as recognized, in a forming electrolyte suitable for forming oxides on a valve metal anode containing an inositol derivative defined by Formula 1. [ka] Formula 1 In the formula,[[]] R 1 ~R 6 are each independently H, a substituted or unsubstituted carbon chain having up to 20 carbon atoms, -PO3R 7 R 8 , -SiR 9 3, -C(O)R 10 and are selected from,[[]]

Chemical formula

[0010] Still another embodiment is a method for forming a solid electrolytic capacitor, which comprises applying a forming electrolyte on the anode, and the forming electrolyte contains an inositol derivative defined by Formula 1.[[]]

Chemical formula

[0011] The present invention relates to an improved solid electrolytic capacitor comprising an improved tantalum oxide dielectric, wherein the characteristics of the solid electrolytic capacitor, particularly the ACC, are significantly improved compared to conventional capacitors. More specifically, the present invention relates to an improved forming electrolyte suitable for use in forming improved tantalum oxide on a tantalum anode with low wet leakage. Capacitors formed with improved tantalum oxide provide an improved solid electrolytic capacitor, especially when used with a solid conductive polymer cathode.

[0012] The high ACC of solid electrolytic capacitors is resolved by forming tantalum oxide on the tantalum anode in an electrolyte containing an inositol derivative. Although not limited to theory, it is hypothesized that the inositol derivative stabilizes the interface between the grown dielectric and anode by being able to bond with free hydroxyl groups or tantalum oxide present on the tantalum surface, thereby promoting the growth of improved tantalum oxide.

[0013] This invention relates to the improvement of electrical characteristics in solid electrolytic capacitors, more specifically, to the improvement of abnormal charge current (ACC). This invention provides a method for forming a dielectric oxide film on a tantalum anode and a method for manufacturing a solid electrolytic capacitor using the same. The formation in the electrolyte of this invention is achieved by free terminal O in ionization in an aqueous solution. - The ions are present and form an improved dielectric oxide layer. While not limited to theory, it is hypothesized that the ionic geometry of the formed electrolyte of the present invention is fixed to the tantalum surface, resulting in the presence of free hydroxyl groups. Ionic bonding / fixation facilitates more electrolyte electron access, resulting in the formation of a uniform oxide. Another hypothesis is that a portion of the formed electrolyte of the present invention remains on the surface of the tantalum oxide, forming a stable interface between the dielectric and conductive polymer at the pn junction. This supports the possibility of tunneling and significantly reduces abnormal charge current (ACC) in solid electrolytic capacitors.

[0014] Forming a stable dielectric interface is crucial for achieving stable electrical properties. The dielectric is formed by anodizing a metal anode in an electrolyte containing the forming electrolyte of the present invention. By selectively controlling the anodizing process over a certain voltage range, the anodizing process leads to a dielectric with better electrical properties, and consequently, an improved capacitor with less abnormal charge current when charged at a constant voltage slew rate such as 100 volts / second.

[0015] Inositol derivatives are defined by formula 1, [ka] formula 1 During the ceremony, R 1 ~R 6 Each of these is independently H, a substituted or unsubstituted carbon chain having up to 20 carbon atoms, and -PO3R 7 R 8 , -SiR 9 3, -C(O)R 10 More selected, [ka] Alternatively, both adjacent groups may represent -P(O)OH-OP(O)OH-. R 7 and R 8 Each of these is independently H, a cation, a saturated or unsaturated carbon chain having up to 35 carbon atoms, or -CH2CHR 12 CH2R 13 More selected, Each R 9 This is an alkyl group having 1 to 10 carbon atoms independently, preferably 1 to 3 carbon atoms, and is particularly preferably -CH3. Each R 10 This is an alkyl group having 1 to 10 carbon atoms independently, preferably 1 to 3 carbon atoms, and is particularly preferably -CH3. Each R 11 This represents the bonding of the inositol derivative of formula 1 to the oxide, R 12 and R 13 These are esters whose terminal carbon chains contain H and 1 to 35 carbon atoms, either saturated or unsaturated.

[0016] In a preferred embodiment, R 1 ~R 6 At least one of them is PO3R 7 R 8 And R 7 or R 8 At least one of them is H, preferably R 7 and R 8Both are H. In a more preferred embodiment, R 1 ~R 6 At least two of them are -PO3R 7 R 8 and R 7 or R 8 At least one of them is H, and preferably R 7 and R 8 Both are H. In a more preferred embodiment, R 1 ~R 6 At least three of them are PO3R 7 R 8 and R 7 or R 8 At least one of them is H, and preferably R 7 and R 8 Both are H. In a more preferred embodiment, R 1 ~R 6 At least four of them are PO3R 7 R 8 and R 7 or R 8 At least one of them is -H, and preferably R 7 and R 8 Both are H. In a more preferred embodiment, R 1 ~R 6 At least five of them are PO3R 7 R 8 and R 7 or R 8 At least one of them is H, and preferably R 7 and R 8 Both are H. In a more preferred embodiment, R 1 ~R 6 Each is PO3R 7 R 8 and R 7 or R 8 At least one of them is -H, and preferably R<000009​​​​​​​​​​The cation may preferably be selected from quaternary amines, ammonium, metal cations, and saturated or unsaturated carbon chains having up to 35 carbon atoms, preferably 10 to 17 carbon atoms.

[0018] Substituents or unsubstituted carbonic acids include alkyl and alkene chains that may be substituted or unsubstituted, and can be linear, branched, or cyclic. Substituents include ethers, -OH groups, carboxylic acids, phosphonic acids, phosphinic acids, esters, amines, and amides.

[0019] Particularly preferred derivatives of inositol include myo-inositol and its isomers and their derivatives, namely myo-inositol hexakisphosphate (phytic acid); pentakis, tory, diphosphate and their isomers; and myo-inositol monophosphate, myo-inositol trispirophosphate, 1-phosphatidyl-myo-inositol, 1-phosphatidyl-myo-inositol-3-phosphate, ononitol, secuoitol, donbonitol, biscumitol, pinitol, quebrachitol, pinpolititol, and derivatives of brahol, myo-inositol 1,3,4,5,6-pentakis-O-(trimethylsilyl)-, bis(trimethylsilyl)phosphate, phosphatidylinositol 5-phosphate PI(5)diC8 ammonium salt, phosphatidylinositol 5-phosphate diC16(PI(5)P Selected from the group consisting of di-C16) sodium salt, 1,2-cyacyl-sn-glycero-3-phospho-(1-D-myo-inositol 4,5-biphosphate), phosphatidylinositol, phosphatidylinositol 3-phosphate, phosphatidylinositol 4-phosphate, phosphatidylinositol 4,5-phosphate, di-myo-inositol-phosphate, ciseritol phosphate, fagopyritol phosphate, glycosylinositol phosphurylceramide, C25,25-alkeditylinositol, ceramide phosphoinositol, D-myo-inositol-4-hydrogen phosphate monoammonium salt, and phosphatidylinositol phosphate.

[0020] The formed electrolyte may further contain additives selected from metal salts, salts of organic acids, salts of inorganic acids, organic acids, inorganic acids, organometallic compounds, inorganic solvents, organic solvents, crosslinking agents, surfactants, and buffering agents.

[0021] The metal salts, inorganic acid salts, and organic acid salts contained in the forming electrolyte may include halides, nitrides, sulfides, amides, nitrates, sulfates, phosphates, carbonates, chromates, chlorates, perchlorates, oxides, acid chlorides, peroxides, carboxylates, amides, and esters.

[0022] The organic and inorganic acids contained in the formed electrolyte may include carboxylic acids, phosphonic acids, phosphinic acids, phosphoric acids, phthalic acids, maleic acids, malonic acids, and trimesic acids.

[0023] The organometallic compounds included in the formed electrolyte may include organosilanes, organoboranes, carbonyls, phosphines, crosslinking agents, surfactants, and buffering agents.

[0024] The solvent included in the forming electrolyte may be selected from the group consisting of water, alcohol, ethylene glycol, polyethylene glycol, tetraglyceride, propylene glycol, glycol ether, and alkanolamines.

[0025] A solid electrolytic capacitor comprises an anode, a cathode, and a dielectric oxide between the anode and the cathode. The anode is a sintered porous tantalum metal anodized to form a dielectric oxide. The dielectric oxide layer is coated with a solid electrolyte, which is preferably a conductive polymer and acts as the cathode. The dielectric oxide is formed by exposing the anode to a voltage in the presence of the forming electrolyte of the present invention in a process referred to in the art as anodizing.

[0026] The solid electrolytic capacitor includes an anode, a cathode, and a dielectric oxide between the anode and the cathode. The anode is a sintered porous tantalum metal anodized to form the dielectric oxide. The dielectric oxide layer is coated with a solid electrolyte, which is preferably a conductive polymer and acts as the cathode. The dielectric oxide is formed by exposing the anode to a voltage in the presence of the forming electrolyte of the present invention in a process referred to in the art as anodizing treatment.

[0027] After the formation of the anode (anodizing treatment), the dielectric thereon can be washed. In one embodiment, the anode having the dielectric is not washed, and the forming electrolyte remaining on the surface is left fixed to promote the bonding with the cathode layer.

[0028] A forming temperature of about 60 to 125 °C is suitable for demonstrating the present invention. More preferably, an anodizing treatment temperature of about 75 to 90 °C is suitable for demonstrating the present invention.

[0029] An abnormal charge current (ACC) refers to an ideal current (Iideal) in milliamperes (mA) for charging a capacitor I ideal = 1000*C(dv / dt), where C is the capacitance in farads and dv / dt is the instantaneous rate of voltage change, usually about 100 V / S. Therefore, the actual charge current remains the same or is higher than the ideal charge current (I ideal ). I ideal / I ideal = 1 or greater than 1.

[0030] The structure of the solid electrolytic capacitor is well understood by those skilled in the art, and no further details are necessary herein.

[0031] Each of the conductive polymers is preferably selected from the group consisting of optionally substituted polyanilines, polypyrroles, and polythiophenes. Particularly preferred polymers include a conjugated system having the structure of Formula 2. [ka] formula 2 In the formula, R 1 and R 2 These are independently linear or branched C1-C 16 Alkyl or C2-C 18 Represents an alkoxyalkyl group; or unsubstituted, or C1-C6 alkyl, C1-C6 alkoxy, halogen, or OR 3 It is a C3-C8 cycloalkyl, phenyl, or benzyl substituted with; or R 1 and R 2 These are, collectively, unsubstituted or linear C1-C6 alkylenes substituted with C1-C6 alkyl, C1-C6 alkoxy, halogen, C3-C8 cycloalkyl, phenyl, benzyl, C1-C4 alkylphenyl, C1-C4 alkoxyphenyl, halophenyl, C1-C4 alkylbenzyl, C1-C4 alkoxybenzyl or halobenzyl, or 5-membered, 6-membered, or 7-membered heterocyclic structures containing two oxygen elements. 3 C1-C is a hydrogen atom, a straight chain, or a branched C1-C atom. 16 Alkyl or C2-C 18 It is preferable to represent an alkoxyalkyl group; or a phenyl or benzyl group substituted with a C3-C8 cycloalkyl group, unsubstituted or C1-C6 alkyl group. X is S, N, or O, most preferably X is S. R in Formula 2 1 and R 2 Since it is most preferable that polymerization proceeds only at the α-site, it is preferable that the element is selected to inhibit polymerization at the β-site of the ring. 1 and R 2 It is more preferably not hydrogen, and even more preferably R 1 and R 2 This is an α-director in which an ether bond is preferred over an alkyl bond. 1 and R 2 It is most preferable that it be small in order to avoid steric hindrance.

[0032] In a particularly preferred embodiment, R of formula 1 1 and R2 In short, -O-(CHR 4 ) n -O- represents -O-, where n is an integer from 1 to 5, and is most preferably 2, R 4 Independently, hydrogen; optionally, linear or branched C1-C1 cells substituted with a functional group selected from carboxylic acids, hydroxyls, amines, substituted amines, alkenes, acrylates, thiols, alkynes, azides, sulfates, sulfonates, sulfonic acids, imides, amides, epoxys, anhydrides, silanes, and phosphates. 18 Alkyl radicals, C5~C 12 Cycloalkyl radical, C6~C 14 Aryl radicals, C7~C 18 Selected from aralkyl radicals, C1-C4 hydroxyalkyl radicals; hydroxyl radicals, or R 4 is, -(CHR 5 ) a -R 16 ;-O(CHR 5 ) a R 16 -CH2O(CHR 5 ) a R 16 -CH2O(CH2CHR 5 O) a R 16 Selected from, R 4 R is a functional group selected from the group consisting of hydroxyl, carboxyl, amine, epoxy, amide, imide, anhydride, hydroxymethyl, alkene, thiol, alkyne, azide, sulfonic acid, benzenesulfonate, SO3M, anhydride, silane, acrylate, and phosphate. 5 H is an alkyl chain having 1 to 5 carbon atoms, optionally substituted with a functional group selected from carboxylic acids, hydroxyls, amines, alkenes, thiols, alkynes, azides, epoxys, acrylates, and anhydrides, and R 16a is an alkyl chain having 1 to 5 carbon atoms substituted with H, SO3M, or optionally a functional group selected from carboxylic acids, hydroxyls, amines, substituted amines, alkenes, thiols, alkynes, azides, amides, imides, sulfates, SO3M, amides, epoxys, anhydrides, silanes, acrylates, and phosphates, where a is an integer from 0 to 10, and M is preferably a cation selected from H, or ammonia, sodium, or potassium.

[0033] The conductive polymer may be either a water-soluble or water-dispersible compound. Examples of such π-conjugated conductive polymers include polypyrrole or polythiophene. Particularly preferred conductive polymers include poly(3,4-ethylenedioxythiophene), poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy)-1-butane-sulfonic acid, salt), poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy)-1-propane-sulfonic acid, salt), and poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy)-1-methyl-1-propane-sulfonic acid, salt). Poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy alcohol, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3-dodecylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-carboxypyrrole), poly(3-methyl-4-carboxypyrrole), poly(3-methyl-4-carboxyethylpyrrole), poly(3-methyl-4 -carboxybutylpyrrole), poly(3-hydroxypyrrole), poly(3-methoxypyrrole), polythiophene, poly(3-methylthiophene), poly(3-hexylthiophene), poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly(3-octadecylthiophene), poly(3-bromothiophene), poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene), poly(3-hydroxythiophene Poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptyloxythiophene), poly(3-octyloxythiophene), poly(3-decyloxythiophene), poly(3-dodecyloxythiophene), poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3,4-dimethoxythiophene), poly(3,4-ethylenedioxythiophene), poly(3,This includes poly(4-propylenedioxythiophene), poly(3,4-butenedioxythiophene), poly(3-carboxythiophene), poly(3-methyl-4-carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), poly(3-methyl-4-carboxybutylthiophene), polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-aniline sulfonate), poly(3-aniline sulfonate), etc.

[0034] A copolymer consisting of at least two different copolymer monomers is conceivable. The copolymer comprises at least one polymerization monomer selected from the group consisting of polypyrrole, polythiophene, poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy)-1-butane-sulfonic acid, salt), poly(4,-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy)-1-methyl-1-propane-sulfonic acid, salt), poly(N-methylpyrrole), poly(3-methylthiophene), poly(3-methoxythiophene), and poly(3,4-ethylenedioxythiophene).

[0035] A particularly preferred conductive polymer is poly-3,4-polyethylenedioxythiophene (PEDOT).

[0036] The conductive polymer layer can be formed on the dielectric by any of the conventionally employed techniques. The conductive polymer can be formed as a slurry and deposited on the surface. Alternatively, the conductive polymer can be added as a monomer and polymerized in situ as is conventionally known.

[0037] In this art, it is known to provide an additional layer on the cathode to facilitate soldering to the lead frame or circuit. Carbon-containing layers and metal-containing layers are well known and well documented in this art, and no further discussion is necessary herein.

[0038] Organic functional silanes or organic compounds having one or more crosslinking groups, particularly one or more epoxy groups, are especially suitable for use in combination with the forming electrolyte of the present invention. The forming electrolyte may also contain organic functional silanes and organic compounds as additives, along with one or more crosslinking agents, in combination with the inositol derivative. After the formation of the dielectric oxide, the anode with the dielectric on it can be washed. In one embodiment, the anode with the dielectric on it is not washed, and residual organic functional silanes and organic compounds with one or more crosslinking agents, along with the inositol derivative, are present during cathode formation.

[0039] An example of an organically functional silane is given by formula: XR1Si(R3) 3-n (R2) n Defined by the formula, where X is an organic functional group such as amino, epoxy, anhydride, hydroxy, mercapto, sulfonate, carboxylate, phosphate, halogen, vinyl, methacryloxy, ester, alkyl, and R1 is an aryl or alkyl (CH2) m Here, m can be 0 to 14, R2 is a hydrolyzable functional group such as an alkoxy, acryloxy, halogen, amine, or hydrolysate thereof, R3 is an alkyl functional group having 1 to 6 carbon atoms, and n is 1 to 3.

[0040] Organic functional silanes are given by formula Y(Si(R3) 3-n (R2) n )2 may also be a dipodal as defined in the formula, where Y is any organic part containing a reactive or nonreactive functional group such as alkyl, aryl, sulfide, or melamine, and R3, R2, and n are as defined above. The organic functional silane may also be a polyfunctional or polymeric silane such as silane-modified polybutadiene or silane-modified polyamide.

[0041] Examples of organically functionalized silanes include 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminopropylsilanetriol, (triethoxysilyl)propyl succinic anhydride, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-trihydroxysilyl-1-propanesulfonic acid, octyltriethoxysilane, and bis(triethoxysilyl)octane. These examples are used as illustrative examples of the present invention and should not be understood as definitive. Examples of organically functionalized silanes include 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, aminopropylsilanetriol, (triethoxysilyl)propyl succinic anhydride, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-trihydroxysilyl-1-propanesulfonic acid, octyltriethoxysilane, and bis(triethoxysilyl)octane. These examples are used as illustrative examples of the present invention and should not be understood as definitive.

[0042] A particularly preferred organic functional silane is the glycidylsilane defined by the following formula. [ka] formula 3 In the formula, R1 is an alkyl having 1 to 14 carbon atoms, more preferably selected from methyl ethyl and propyl, and R2 is independently an alkyl, a substituted alkyl, or a substituted alkyl having 1 to 6 carbon atoms.

[0043] A particularly suitable glycidylsilane is 3-glycidoxypropyltrimethoxysilane, defined by the following formula. [ka] formula 4 For convenience, this will be referred to as "Silane A" in this specification.

[0044] Particularly preferred organometallic compounds include titanium IV2,2(bis2-propenolate methyl)butanolate, tris neodecanoate-O; titanium IV2,2(bis2-propenolate methyl)butanolate, iris(dodecyl)benzenesulfonate-O; titanium IV2,2(bis2-propenolate methyl)butanolate, tris(dioctyl)phosphatate-O; titanium IV2,2(bis2-propenolate methyl)tris(dioctyl)pyrophosphatebutanolate-O; titanium IV2,2(bis2-propenolate methyl)butanolate, tris(2-ethylenediamino)ethylate; and titanium IV2,2(bis2-propenolate methyl)butanolate, tris(3-amino)phenylate, which are representative neoalkoxy titanates and their derivatives.

[0045] A crosslinking agent comprising at least two epoxy groups is referred to herein as an epoxy crosslinking compound and is defined by the following formula: [ka] formula 5 In the formula, X is an alkyl or substituted alkyl having 0 to 14 carbon atoms, preferably 0 to 6 carbon atoms; an aryl or substituted aryl; an ethylene ether or substituted ethylene ether; a polyethylene ether or substituted polyethylene ether having 2 to 20 ethylene ether groups; or a combination thereof. A particularly preferred substituent is an epoxy group.

[0046] Examples of epoxy crosslinked compounds having more than one epoxy group include ethylene glycol diglycidyl ether (EGDGE), propylene glycol diglycidyl ether (PGDGE), 1,4-butanediol diglycidyl ether (BDDGE), pentylene glycol diglycidyl ether, hexylene glycol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, resorcinol glycidyl ether, glycerol diglycidyl ether (GDGE), glycerol polyglycidyl ethers, diglycerol polyglycidyl ethers, and trimethylolpropane polyglycidyl ethers. Examples include ethers, sorbitol diglycidyl ether (sorbitol-DGE), sorbitol polyglycidyl ethers, polyethylene glycol diglycidyl ether (PEGDGE), polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, di(2,3-epoxypropyl) ether, 1,3-butadiene diepoxide, 1,5-hexadiene diepoxide, 1,2,7,8-diepoxyoctane, 1,2,5,6-diepoxycyclooctane, 4-vinylcyclohexene diepoxide, bisphenol A diglycidyl ether, maleimide-epoxy compounds, and the like. [Examples]

[0047] Wet capacitance and leakage are measured using an LCR meter with 25 wt% phosphoric acid in water at a test frequency of 120 Hz and a test voltage of 70% of the forming voltage. For wet leakage, the component was tested with a DC bias voltage of 2 V after a 120 second charge time. ACC (abnormal charge current) is measured at the end of the production process. The finished component is mounted on a circuit board, and measurements are taken at 0°C and 80% Vr, expressed as a time-theoretical value (xTLV).

[0048] Comparative example: A tantalum anode (330 microfarads, rated voltage 16V) was prepared by sintering tantalum powder. First, a dielectric oxide was formed on the tantalum anode by anodizing it in an electrolyte acting as a control {approximately (2-5 wt%) phosphoric acid, (50-70 wt%) ethylene glycol, and water with a resistance of approximately (100-370) ohms-cm at 35V and 80°C} (first anodizing treatment). The anode was rinsed, heat-treated at 450°C for 30 minutes, and anodized again in the original electrolyte. The wet leakage after the first anodizing treatment is shown in Table 1. Subsequently, the anode was coated with a conductive polymer that functions as a cathode, and then coated with carbon and silver. Using known techniques, the components were assembled and formed into a surface-mounted finished capacitor. The ACC (Acoustic Acceleration) is measured at 0°C on the mounted component and reported as current in mA at 12.8V {80% of the rated voltage (Vr)}. The capacitor and ESR (Equivalent Series Resistance) of the finished product are also reported in Table 1 along with the ACC.

[0049] Embodiment 1 of the Invention: A series of solid electrolytic capacitors were prepared in the same manner as in Comparative Example 1, using 300 microfarad components at a rated voltage of 16V, except that the electrolyte was (5-10 wt%) inositol-6-phosphate in water with a resistance of (7-15) ohms-cm at 80°C. The wet leakage after the first anodizing treatment, the cap and ESR of the finished product when a current (mA) is applied at 12.8V (80% of Vr), are also reported in Table 1 along with the ACC.

[0050] Embodiment 2 of the invention: A series of solid electrolytic capacitors were prepared in the same manner as in Example 1 of the present invention, using 300 microfarad components at a rated voltage of 16V, except that the anodized electrolyte was a mixture (1:1) of (5-10 wt%) inositol-6-phosphate and epoxysilane in water with a resistance of (9-17) ohms-cm at 80°C. The wet leakage after the first anodizing process, the cap and ESR of the finished product when a current (mA) at 12.8V (80% of Vr) is applied are also reported in Table 1 along with the ACC.

[0051] Embodiment 3 of the invention: In this example, a series of solid electrolytic capacitors were prepared using 300 microfarad components at a rated voltage of 16V, in the same manner as in Example 1 of the present invention, except that ethylene glycol (EG) was added to the electrolyte. Inositol-6-phosphate (5-10 wt%) was added to ethylene glycol (50-70 wt%) in water having a resistance of (75-100) ohms-cm at 80°C. Wet leakage after the first anodizing treatment, the cap and ESR of the finished product when a current (mA) at 12.8V (80% of Vr) was applied are also reported in Table 1 along with ACC.

[0052] Embodiment 4 of the invention: In this example, a series of solid electrolytic capacitors were prepared using 300 microfarad components at a rated voltage of 16V, in the same manner as in Example 2 of the present invention, except that the polymer also has the same electrolyte as that used with the conductive polymer in Example 2 of the present invention. The wet leakage after the first anodizing process, the cap and ESR of the finished product when a current (mA) at 12.8V (80% of Vr) is applied are also reported in Table 1 along with the ACC.

[0053] Example 5 of the invention: In this example, a series of solid electrolytic capacitors were prepared using 300 microfarad components at a rated voltage of 16V, in the same manner as in Example 1 of the present invention, except that the electrolyte consisted of inositol (1-6 wt%) and phosphoric acid (1-6 wt%) in water with a resistance of approximately (10-30) ohms-cm. The wet leakage after the first anodizing process, the cap and ESR of the finished product when a current (mA) at 12.8V (80% of Vr) is applied are also reported in Table 1 along with the ACC.

[0054] [Table 1]

[0055] The embodiments of the invention demonstrate the ability to form capacitors using the invention's forming electrolyte, which has an abnormal charge current of less than four times the theoretical value. Otherwise, this would be unavailable in the prior art.

[0056] The present invention has been described with reference to preferred embodiments without limitation. Those skilled in the art will recognize further embodiments described and included in the appended claims.

Claims

1. A suitable forming electrolyte for forming an oxide on a valve metal anode, comprising an inositol derivative defined by formula 1, 【Chemistry 1】 Formula 1 During the ceremony, R １ ~R ６ Each is independently H, a substituted or unsubstituted carbon chain having up to 20 carbon atoms, -PO ３ R ７ R ８ , -SiR ９ ３ , -C(O)R １０ More selected, 【Chemistry 2】 Alternatively, both adjacent groups may represent -P(O)OH-O-P(O)OH-. R ７ and R ８ each independently is H, a cation, a saturated or unsaturated carbon chain having up to 35 carbon atoms, or -CH ２ CHR １２ CH ２ R １３ is selected from, Each R ９ These are alkyl groups that independently have 1 to 10 carbon atoms. Each R １０ These are alkyl groups that independently have 1 to 10 carbon atoms. Each R １１ This represents the bonding of the inositol derivative of formula 1 to the oxide, R １２ and R １３ This is a forming electrolyte that is an ester having a saturated or unsaturated carbon chain with H and 1 to 35 carbon atoms at its terminals.

2. R １ ~R ６ At least one of them is -PO ３ R ７ R ８ And R ７ or R ８ A suitable forming electrolyte for forming an oxide on a tantalum anode according to claim 1, wherein at least one of the is -H.

3. R ７ and R ８ Both are -H, a suitable forming electrolyte for forming an oxide on a tantalum anode according to claim 2.

4. R １ ~R ６ At least two of them are -PO ３ R ７ R ８ A formation electrolyte suitable for forming an oxide on a tantalum anode, as described in claim 2.

5. R １ ~R ６ At least three of them are -PO ３ R ７ R ８ A formation electrolyte suitable for forming an oxide on a tantalum anode, as described in claim 4.

6. R １ ~R ６ At least four of them are -PO ３ R ７ R ８ A formation electrolyte suitable for forming an oxide on a tantalum anode, as described in claim 5.

7. R １ ~R ６ At least five of them are -PO ３ R ７ R ８ A suitable forming electrolyte for forming an oxide on a tantalum anode according to claim 6.

8. R １ ~R ６ Each of these is -PO ３ R ７ R ８ A formation electrolyte suitable for forming an oxide on a tantalum anode, as described in claim 7.

9. R ７ and R ８ Each of these is -H, making them suitable forming electrolytes for forming oxides on a tantalum anode according to claim 8.

10. R ７ and R ８ A suitable forming electrolyte for forming an oxide on a tantalum anode according to claim 1, wherein at least one of the elements is a cation.

11. The cation is selected from the group consisting of quaternary amines and saturated or unsaturated carbon chains having up to 35 carbon atoms. Forming electrolyte suitable for forming an oxide on a tantalum anode according to claim 10.

12. R ９ The forming electrolyte is suitable for forming an oxide on a tantalum anode according to claim 1, wherein each atom is an alkyl having 1 to 3 carbon atoms independently.

13. R ９ These are, respectively, -CH ３ A formation electrolyte suitable for forming an oxide on a tantalum anode, as described in claim 12.

14. R １０ The forming electrolyte is suitable for forming an oxide on a tantalum anode according to claim 1, wherein each atom is an alkyl having 1 to 3 carbon atoms independently.

15. R １０ These are, respectively, -CH ３ A formation electrolyte suitable for forming an oxide on a tantalum anode, as described in claim 14.

16. The inositol derivatives include myo-inositol and its isomers and their derivatives, namely myo-inositol hexakisphosphate (phytic acid); pentakis, tory, diphosphate and their isomers; and myo-inositol monophosphate, myo-inositol trispirophosphate, 1-phosphatidyl-myo-inositol, 1-phosphatidyl-myo-inositol-3-phosphate, ononitol, secuoitol, donbonitol, biscumitol, pinitol, quebrachitol, pinpolititol, and derivatives of brahol, myo-inositol 1,3,4,5,6-pentakis-O-(trimethylsilyl)-, bis(trimethylsilyl)phosphate, phosphatidylinositol 5-phosphate PI(5) diC8 ammonium salt, phosphatidylinositol 5-phosphate diC16(PI(5)P A suitable forming electrolyte for forming an oxide on a tantalum anode, as described in claim 1, selected from the group consisting of di-C16) sodium salt, 1,2-cyacyl-sn-glycero-3-phospho(1-D-myo-inositol 4,5-biphosphate), phosphatidylinositol, phosphatidylinositol 3-phosphate, phosphatidylinositol 4-phosphate, phosphatidylinositol 4,5-phosphate, di-myo-inositol-phosphate, ciseritol phosphate, fagopyritol phosphate, glycosylinositol phosphurylceramide, C25,25-alkeditylinositol, ceramide phosphoinositol, D-myo-inositol-4-hydrogen phosphate monoammonium salt, and phosphatidylinositol phosphate, and D-myo-inositol-4-hydrogen phosphate monoammonium salt.

17. A forming electrolyte suitable for forming an oxide on a valve metal anode according to claim 1, further comprising an additive selected from metal salts, salts of organic acids, salts of inorganic acids, organic acids, inorganic acids, organometallic compounds, inorganic solvents, organic solvents, crosslinking agents, surfactants, and buffers.

18. The formation electrolyte suitable for forming an oxide on a valve metal anode according to claim 17, wherein the metal salt, inorganic acid salt, and organic acid salt include halides, nitrides, sulfides, amides, nitrates, sulfates, phosphates, carbonates, chromates, chlorates, perchlorates, oxides, acid chlorides, peroxides, carboxylates, amides, and esters.

19. The formation electrolyte suitable for forming oxides on a valve metal anode according to claim 17, wherein the organic and inorganic acids include carboxylic acids, phosphonic acids, phosphinic acids, phosphoric acids, phthalic acids, maleic acids, malonic acids, and trimesic acids.

20. The organometallic compound comprises an organosilane, an organoborane, a carbonyl, a phosphine, a crosslinking agent, a surfactant, and a buffering agent. Forming electrolyte suitable for forming an oxide on a valve metal anode according to claim 17.

21. A suitable forming electrolyte for forming an oxide on a valve metal anode according to claim 17, further comprising at least one solvent selected from the group consisting of water, alcohol, ethylene glycol, polyethylene glycol, tetraglyceride, propylene glycol, glycol ethers, and alkanolamines.

22. A method for forming a solid electrolytic capacitor, The method involves applying a formed electrolyte to the anode, wherein the formed electrolyte includes an inositol derivative defined by formula 1. 【Transformation 3】 Formula 1 During the ceremony, R １ ~R ６ Each is independently H, a substituted or unsubstituted carbon chain having up to 20 carbon atoms, -PO ３ R ７ R ８ , -SiR ９ ３ , -C(O)R １０ More selected, 【Chemistry 4】 formula Alternatively, both adjacent groups may represent -P(O)OH-O-P(O)OH-. R ７ and R ８ Each of these is independently H, a cation, a saturated or unsaturated carbon chain having up to 35 carbon atoms, or -CH ２ CHR １２ CH ２ R １３ More selected, Each R ９ These are alkyl groups that independently have 1 to 10 carbon atoms. Each R １０ These are alkyl groups that independently have 1 to 10 carbon atoms. Each R １１ This represents the bonding of the inositol derivative of formula 1 to the oxide, R １２ and R １３ This is an ester having H, 1 to 35 carbon atoms, and a saturated or unsaturated carbon chain at its end, thereby forming a dielectric oxide on the tantalum anode, A method for forming a solid electrolytic capacitor, comprising forming a conductive polymer cathode on the dielectric oxide.

23. R １ ~R ６ At least one of them is -PO ３ R ７ R ８ And R ７ or R ８ The method for forming a solid electrolytic capacitor according to claim 22, wherein at least one of the is -H.

24. R ７ and R ８ The method for forming a solid electrolytic capacitor according to claim 23, wherein both are -H.

25. R １ ~R ６ At least two of them are -PO ３ R ７ R ８ The method for forming a solid electrolytic capacitor according to claim 23.

26. R １ ~R ６ Among them, at least three are -PO ３ R ７ R ８ The method for forming a solid electrolytic capacitor according to claim 25, wherein this is the case.

27. R １ ~R ６ At least four of them are -PO ３ R ７ R ８ The method for forming a solid electrolytic capacitor according to claim 25.

28. R １ ~R ６ At least five of them are -PO ３ R ７ R ８ The method for forming a solid electrolytic capacitor according to claim 27.

29. R １ ~R ６ Each of these is -PO ３ R ７ R ８ The method for forming a solid electrolytic capacitor according to claim 27.

30. R ７ and R ８ The method for forming a solid electrolytic capacitor according to claim 29, wherein each of these is -H.

31. R ７ and R ８ The method for forming a solid electrolytic capacitor according to claim 22, wherein at least one of the elements is a cation.

32. The method for forming a solid electrolytic capacitor according to claim 22, wherein the cation is selected from the group consisting of quaternary amines and saturated or unsaturated carbon chains having up to 35 carbon atoms.

33. R ９ The method for forming a solid electrolytic capacitor according to claim 22, wherein each of them is an alkyl having 1 to 3 carbon atoms independently.

34. R ９ These are, respectively, -CH ３ The method for forming a solid electrolytic capacitor according to claim 33.

35. R １０ The method for forming a solid electrolytic capacitor according to claim 22, wherein each of them is an alkyl having 1 to 3 carbon atoms independently.

36. R １０ These are, respectively, -CH ３ The method for forming a solid electrolytic capacitor according to claim 35.

37. The inositol derivatives include myo-inositol and its isomers and their derivatives, namely myo-inositol hexakisphosphate (phytic acid); pentakis, tory, diphosphate and their isomers; and myo-inositol monophosphate, myo-inositol trispirophosphate, 1-phosphatidyl-myo-inositol, 1-phosphatidyl-myo-inositol-3-phosphate, ononitol, secuoitol, donbonitol, biscumitol, pinitol, quebrachitol, pinpolititol, and derivatives of brahol, myo-inositol 1,3,4,5,6-pentakis-O-(trimethylsilyl)-, bis(trimethylsilyl)phosphate, phosphatidylinositol 5-phosphate PI(5) diC8 ammonium salt, phosphatidylinositol 5-phosphate diC16(PI(5)P A method for forming a solid electrolytic capacitor according to claim 22, wherein the selected material is from the group consisting of diC16) sodium salt, 1,2-cyacyl-sn-glycero-3-phospho(1-D-myoinositol 4,5-biphosphate), phosphatidylinositol, phosphatidylinositol 3-phosphate, phosphatidylinositol 4-phosphate, phosphatidylinositol 4,5-phosphate, di-myoinositol-phosphate, ciseritol phosphate, fagopyritol phosphate, glycosylinositol phosphurylceramide, C25,25-alkeditylinositol, ceramide phosphoinositol, D-myoinositol-4-hydrogen phosphate monoammonium salt, and phosphatidylinositol phosphate.

38. A method for forming a solid electrolytic capacitor according to claim 22, further comprising an additive selected from metal salts, salts of organic acids, salts of inorganic acids, organic acids, inorganic acids, organometallic compounds, inorganic solvents, organic solvents, crosslinking agents, surfactants, and buffering agents.

39. The method for forming a solid electrolytic capacitor according to claim 38, wherein the metal salt, inorganic acid salt, and organic acid salt include halides, nitrides, sulfides, amides, nitrates, sulfates, phosphates, carbonates, chromates, chlorates, perchlorates, oxides, acid chlorides, peroxides, carboxylates, amides, and esters.

40. The method for forming a solid electrolytic capacitor according to claim 38, wherein the organic and inorganic acids include carboxylic acids, phosphonic acids, phosphinic acids, phosphoric acids, phthalic acids, maleic acids, malonic acids, and trimesic acids.

41. The method for forming a solid electrolytic capacitor according to claim 38, wherein the organometallic compound includes organosilane, organoborane, carbonyl, phosphine, crosslinking agent, surfactant, and buffering agent.

42. The method for forming a solid electrolytic capacitor according to claim 22, wherein the forming electrolyte further comprises at least one solvent selected from the group consisting of water, alcohol, ethylene glycol, polyethylene glycol, tetraglyceride, propylene glycol, glycol ether, and alkanolamines.

43. The conductive polymers include poly(3,4-ethylenedioxythiophene), poly(4-2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy-1-butanesulfonic acid, salt, poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy)-1-propanesulfonic acid, salt, poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy)-1-methyl-1-propanesulfonic acid, salt), and poly(4-(2,3-dihydrothieno-[3,4-b][1,4]dioxin-2-yl)methoxy) Alcohol, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3-dodecylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-carboxypyrrole), poly(3-methyl-4-carboxypyrrole), poly(3-methyl-4-carboxyethylpyrrole), poly(3-methyl-4-carboxybutylpyrrole), poly(3-hydroxypyrrole), poly(3-methoxypyrrole), polythiophene, poly(3-methylthiophene), poly(3-hexylthiophene), poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly (3-octadecylthiophene), poly(3-bromothiophene), poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene), poly(3-hydroxythiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptyloxythiophene), poly(3-octyloxythiophene), poly(3-decyloxythiophene), poly(3-dodecyloxythiophene), poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3,4-dimethoxythiophene), poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), poly(3,A method for forming a solid electrolytic capacitor according to claim 22, wherein the selected material is from the group consisting of 4-butenedioxythiophene, poly(3-carboxythiophene), poly(3-methyl-4-carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), poly(3-methyl-4-carboxybutylthiophene), polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-aniline sulfonate), and poly(3-aniline sulfonate).

44. The method for forming a solid electrolytic capacitor according to claim 22, wherein the dielectric is not cleaned prior to the formation of the conductive polymer cathode.

45. A capacitor comprising an anode prepared by anodizing compressed valve metal powder in the electrolyte of claim 22.

46. The capacitor according to claim 45, wherein the conductive polymer layer comprises an inner polymer layer and an outer polymer layer, and the inner and outer polymers comprise a prepolymerized conductive polymer.

47. The capacitor according to claim 45, having an abnormal charge current less than four times the theoretical value.

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