JPH1187186A - Etching method for electrode foil for aluminum electrolytic capacitor - Google Patents

Etching method for electrode foil for aluminum electrolytic capacitor

Info

Publication number
JPH1187186A
JPH1187186A JP9248059A JP24805997A JPH1187186A JP H1187186 A JPH1187186 A JP H1187186A JP 9248059 A JP9248059 A JP 9248059A JP 24805997 A JP24805997 A JP 24805997A JP H1187186 A JPH1187186 A JP H1187186A
Authority
JP
Japan
Prior art keywords
etching
acid
sulfuric acid
weight
aqueous solution
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP9248059A
Other languages
Japanese (ja)
Inventor
Yoshihiro Watanabe
善博 渡辺
Koichi Kojima
浩一 小島
Masahiko Taihei
雅彦 太平
Kazuaki Nakanishi
和明 中西
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP9248059A priority Critical patent/JPH1187186A/en
Publication of JPH1187186A publication Critical patent/JPH1187186A/en
Pending legal-status Critical Current

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/13Energy storage using capacitors

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  • ing And Chemical Polishing (AREA)

Abstract

PROBLEM TO BE SOLVED: To obtain an etching method in which a pit diameter can be expanded to a diameter suitable for a chemical conversion voltage, by a method wherein, in a later-stage etching process, an etching operation is performed in an electrolytic solution which is composed of, at least, one kind out of sulfuric acid and nitric acid and, after that, an etching operation is performed in an acid aqueous solution which is composed of, at least, one kind out of hydrochloric acid and sulfuric acid. SOLUTION: In a later-stage etching process, an etching operation is performed electrochemically in an electrolytic solution which is composed of at least one kind out of sulfuric acid and nitric acid, and, after that, a chemical etching operation is performed in an acid aqueous solution which is composed of,at least, one kind out of hydrocholic acid and sulfuric acid. In this case, the concentration of the electrolytic solution which is composed of, at least, one kind out of sulfuric acid and nitric acid is set in a range of 0.5 to 9 wt.%, and a solution temperature is set in a range of 50 to 80 deg.C. In addition, 0.1 to 0.5 wt.% of an additive which is composed of, at least, one kind out of oxalic acid, phosphoric acid and acetic acid is added to the electrolytic solution which is composed of at least one kind out of sulfuric acid and nitric acid.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明はアルミ電解コンデン
サ用電極箔のエッチング方法に関するものであり、さら
に詳しく言えば、高圧用のアルミ電解コンデンサ用電極
箔のエッチング方法に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for etching an electrode foil for an aluminum electrolytic capacitor, and more particularly to a method for etching an electrode foil for an aluminum electrolytic capacitor for high pressure.

【0002】[0002]

【従来の技術】一般にアルミ電解コンデンサは、エッチ
ング工程によって実効表面積を拡大させたアルミニウム
箔の表面に化成工程により誘電体となる酸化皮膜を形成
した陽極箔と、陰極箔をその間にセパレータを介在させ
て巻回することによりコンデンサ素子を構成し、このコ
ンデンサ素子に駆動用電解液を含浸させ、そしてこのコ
ンデンサ素子を金属ケース内に封止することにより構成
している。
2. Description of the Related Art Generally, an aluminum electrolytic capacitor has an anode foil in which an oxide film serving as a dielectric is formed on a surface of an aluminum foil whose effective surface area is enlarged by an etching process and a cathode foil, and a separator is interposed therebetween. To form a capacitor element, impregnating the capacitor element with a driving electrolyte, and sealing the capacitor element in a metal case.

【0003】上記したアルミ電解コンデンサにおけるア
ルミニウム箔のエッチングは、アルミニウム箔の表面を
腐食させることにより粗面化しているもので、一般には
硫酸、硝酸、燐酸、蓚酸などの皮膜を形成する酸を添加
した塩化物溶液中で化学的あるいは電気化学的に行われ
ている。そしてこのエッチングによりアルミニウム箔の
表面を粗面化する理由は、アルミ電解コンデンサの静電
容量がアルミニウム箔の表面積に比例することに基づい
ており、単位面積当たりの静電容量を大きくすることに
より、アルミ電解コンデンサの小型化・軽量化が行え
る。
[0003] The etching of the aluminum foil in the aluminum electrolytic capacitor described above is roughened by corroding the surface of the aluminum foil. In general, an acid for forming a film such as sulfuric acid, nitric acid, phosphoric acid, oxalic acid is added. It is performed chemically or electrochemically in a chloride solution. The reason for roughening the surface of the aluminum foil by this etching is based on the fact that the capacitance of the aluminum electrolytic capacitor is proportional to the surface area of the aluminum foil, and by increasing the capacitance per unit area, Aluminum electrolytic capacitors can be reduced in size and weight.

【0004】特に、中高圧用の電極箔では前段エッチン
グ工程で生成されたピットを後段エッチング工程で化成
電圧に適したピット径まで拡大させる必要があり、いか
に効率よくピット径を拡大させるかが重要なポイントと
なる。従来は前段エッチング工程で、塩素イオンを含む
酸性溶液中での電気エッチングによってピットを発生さ
せ、そして後段エッチング工程で、高温の酸性溶液中で
化学溶解を行ったり、あるいは、特開平2−30301
8号公報、特開平3−101213号公報、特開平3−
136226号公報に示されているように硝酸イオンを
含む酸性溶液中で電気エッチングを行うことによりピッ
トの径を拡大させる技術が有効とされている。
In particular, for electrode foils for medium and high pressures, it is necessary to enlarge the pits generated in the first etching step to a pit diameter suitable for the formation voltage in the second etching step, and it is important how to efficiently increase the pit diameter. It will be a point. Conventionally, pits are generated by electric etching in an acidic solution containing chlorine ions in the first etching step, and chemical dissolution is performed in a high-temperature acidic solution in the second etching step, or
No. 8, JP-A-3-101213, JP-A-3-101213
As described in JP-A-136226, a technique for enlarging the diameter of a pit by performing electric etching in an acidic solution containing nitrate ions has been considered to be effective.

【0005】[0005]

【発明が解決しようとする課題】しかしながら、上記し
た従来の技術では、前段エッチング工程における直流エ
ッチングで生成されたピットを後段エッチング工程にお
けるエッチング方法で化成電圧に適したピット径まで拡
大させることは難しいというのが実状である。その原因
としては、前段エッチング工程における直流エッチング
で生成されるピット径がまちまちで、後段エッチング工
程におけるピット径拡大において高温の酸性溶液中で化
学溶解を行うとそのままピット径が拡大されてしまいピ
ット径に分布のバラツキが生じてしまう。そのため、前
段エッチング工程における直流エッチングで生成された
ピットは全部使用されることなく、次の化成工程におけ
る化成で埋まってしまい、無効とされてしまうことが考
えられる。また、硝酸イオンを含む酸性溶液中で電気エ
ッチングによりピットの径を拡大させる方法では、ピッ
ト径は均一になるものの、化成電圧に適したピット径ま
で拡大されず、静電容量が低いものになっていた。
However, in the above-mentioned prior art, it is difficult to enlarge the pits generated by the DC etching in the pre-etching step to the pit diameter suitable for the formation voltage by the etching method in the post-etching step. That is the actual situation. The reason for this is that the pit diameter generated by DC etching in the pre-etching process varies, and the pit diameter in the post-etching process increases when chemical dissolution is performed in a high-temperature acidic solution. Causes a variation in distribution. For this reason, it is conceivable that all the pits generated by the DC etching in the previous etching step are not used, but are filled by the formation in the next chemical formation step, and become invalid. In the method of expanding the pit diameter by electric etching in an acidic solution containing nitrate ions, the pit diameter becomes uniform, but the pit diameter is not expanded to a suitable pit diameter for the formation voltage, resulting in a low capacitance. I was

【0006】本発明は上記従来の問題点を解決するもの
で、ピット径の拡大を行う後段エッチング工程におい
て、ピット径の均一化と化成電圧に適したピット径まで
の拡大が図れて単位面積当たりの静電容量を高めること
ができるアルミ電解コンデンサ用電極箔のエッチング方
法を提供することを目的とするものである。
The present invention solves the above-mentioned conventional problems. In a subsequent etching step for increasing the pit diameter, the pit diameter is made uniform and the pit diameter suitable for the formation voltage can be increased. It is an object of the present invention to provide a method for etching an electrode foil for an aluminum electrolytic capacitor which can increase the capacitance of the electrode foil.

【0007】[0007]

【課題を解決するための手段】上記目的を達成するため
に本発明のアルミ電解コンデンサ用電極箔のエッチング
方法は、アルミニウム箔を電気化学的にエッチングする
ことによりピットを生成させる前段エッチング工程と、
この前段エッチング工程により生成されたピットを化成
電圧に適したピット径に拡大させる後段エッチング工程
とを有し、前記後段エッチング工程は、硫酸あるいは硝
酸の少なくとも1種類以上の電解液中で電気化学的にエ
ッチングを行い、その後、塩酸あるいは硫酸の少なくと
も1種類以上の酸性水溶液中で化学エッチングを行うよ
うにしたもので、このエッチング方法によれば、ピット
径の拡大を行う後段エッチング工程において、ピット径
の均一化と化成電圧に適したピット径までの拡大が図れ
て単位面積当たりの静電容量を高めることができるもの
である。
In order to achieve the above object, the present invention provides a method for etching an electrode foil for an aluminum electrolytic capacitor, comprising: a pre-etching step of forming pits by electrochemically etching an aluminum foil;
A post-etching step of enlarging the pits generated by the pre-etching step to a pit diameter suitable for the formation voltage, wherein the post-etching step is performed in an electrolytic solution of at least one type of sulfuric acid or nitric acid. Etching is performed in an acidic aqueous solution of at least one kind of hydrochloric acid or sulfuric acid. According to this etching method, the pit diameter is increased in a subsequent etching step for enlarging the pit diameter. And the pit diameter suitable for the formation voltage can be increased to increase the capacitance per unit area.

【0008】[0008]

【発明の実施の形態】本発明の請求項1に記載の発明
は、アルミニウム箔を電気化学的にエッチングすること
によりピットを生成させる前段エッチング工程と、この
前段エッチング工程により生成されたピットを化成電圧
に適したピット径に拡大させる後段エッチング工程とを
有し、前記後段エッチング工程は、硫酸あるいは硝酸の
少なくとも1種類以上の電解液中で電気化学的にエッチ
ングを行い、その後、塩酸あるいは硫酸の少なくとも1
種類以上の酸性水溶液中で化学エッチングを行うように
したもので、このエッチング方法によれば、後段エッチ
ング工程において、硫酸あるいは硝酸の少なくとも1種
類以上の電解液中で電気化学的にエッチングを行うよう
にしているため、前段エッチング工程で生成された三角
錐状のピット形状を円柱でかつ径の揃ったピット形状に
することができ、そしてこの後、塩酸あるいは硫酸の少
なくとも1種類以上の酸性水溶液中で化学エッチングを
行うようにしているため、化成電圧に適したピット径ま
で確実に拡大することができ、これにより、次の化成工
程において、化成の酸化皮膜でピットが埋まってしまう
ということはなくなるため、単位面積当たりの静電容量
を高めることができるものである。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a pre-etching step of forming pits by electrochemically etching an aluminum foil, and a pit formed by the pre-etching step. A post-etching step of expanding to a pit diameter suitable for the voltage, wherein the post-etching step electrochemically etches in at least one or more of an electrolytic solution of sulfuric acid or nitric acid, and then performs etching of hydrochloric acid or sulfuric acid. At least one
According to this etching method, electrochemical etching is performed in at least one or more kinds of electrolytes of sulfuric acid or nitric acid in a subsequent etching step. Therefore, the triangular pyramid pit shape generated in the previous etching step can be made into a pit shape having a cylindrical shape and a uniform diameter, and after that, in at least one kind of acidic aqueous solution of hydrochloric acid or sulfuric acid. Since the chemical etching is performed in the pit, the pit diameter suitable for the formation voltage can be surely enlarged, thereby preventing the pit from being filled with the oxide film of the formation in the next formation process. Therefore, the capacitance per unit area can be increased.

【0009】請求項2に記載の発明は、硫酸あるいは硝
酸の少なくとも1種類以上の電解液の濃度を0.5〜9
重量%の範囲に設定し、かつ液温を50〜80℃の範囲
に設定したもので、この方法によれば、電解液の濃度を
0.5〜9重量%の範囲に設定するとともに、液温を5
0〜80℃の範囲に設定したことにより、アルミニウム
箔中の不純物や粒界の影響を少なくしてエッチングの過
溶解を制御できるため、ピット径の均一化と化成電圧に
適したピット径までの拡大が効果的に行われて単位面積
当たりの静電容量を高めることができるものである。
According to a second aspect of the present invention, the concentration of at least one type of electrolyte solution of sulfuric acid or nitric acid is 0.5 to 9%.
%, And the solution temperature is set in the range of 50 to 80 ° C. According to this method, the concentration of the electrolyte is set in the range of 0.5 to 9% by weight, and Temperature 5
By setting the temperature in the range of 0 to 80 ° C., the influence of impurities and grain boundaries in the aluminum foil can be reduced and the overdissolution of the etching can be controlled, so that the pit diameter is uniform and the pit diameter is suitable for the formation voltage. The enlargement is performed effectively, and the capacitance per unit area can be increased.

【0010】請求項3に記載の発明は、硫酸あるいは硝
酸の少なくとも1種類以上の電解液に蓚酸、燐酸、酢酸
の少なくとも1種類の添加剤を0.1〜0.5重量%添
加するようにしたもので、この方法によれば、添加剤の
添加量を0.1〜0.5重量%の範囲に設定したことに
より、エッチングの過溶解を効果的に抑制することがで
きるため、ピット径の均一化と拡大が効果的に行われ
て、より高い静電容量を得ることができるものである。
According to a third aspect of the present invention, at least one additive of oxalic acid, phosphoric acid, and acetic acid is added to at least one or more electrolytes of sulfuric acid or nitric acid in an amount of 0.1 to 0.5% by weight. According to this method, by setting the amount of the additive in the range of 0.1 to 0.5% by weight, overdissolution of the etching can be effectively suppressed. Is effectively made uniform and enlarged, and a higher capacitance can be obtained.

【0011】請求項4に記載の発明は、化学エッチング
を行う塩酸あるいは硫酸の少なくとも1種類以上の酸性
水溶液の濃度を3〜10重量%の範囲に設定したもの
で、この濃度が3重量%以下の場合は、濃度が薄すぎて
ピット径の拡大をするまでに至らず、一方、濃度が10
重量%以上の場合は、濃度が濃すぎてピット径の拡大の
コントロールができなくなるものであり、したがって、
前記酸性水溶液の濃度は3〜10重量%の範囲が好適で
ある。
According to a fourth aspect of the present invention, the concentration of at least one kind of acidic aqueous solution of hydrochloric acid or sulfuric acid for performing chemical etching is set in a range of 3 to 10% by weight, and the concentration is 3% by weight or less. In the case of, the density is too low to increase the pit diameter, while the density is 10
If it is more than 10% by weight, the density is too high to control the enlargement of the pit diameter.
The concentration of the acidic aqueous solution is preferably in the range of 3 to 10% by weight.

【0012】以下、本発明の具体的な実施の形態につい
て説明する。 (実施の形態1)純度が99.98%で、厚みが100
μmのアルミニウム箔を濃度が0.5重量%の水酸化ナ
トリウム水溶液中に浸漬して前処理を行い、次に濃度が
それぞれ10重量%の塩酸と硫酸を含み、かつ液温が8
5℃の酸性水溶液中で前処理を行ったアルミニウム箔に
電流密度が20A/dm2の直流電流を200秒間印加
してアルミニウム箔を電気化学的にエッチングすること
によりピットを生成させる前段エッチングを行った。
Hereinafter, specific embodiments of the present invention will be described. Embodiment Mode 1 Purity is 99.98% and thickness is 100
A pretreatment is performed by immersing the aluminum foil having a thickness of 0.5 μm in an aqueous solution of sodium hydroxide having a concentration of 0.5% by weight, and then containing hydrochloric acid and sulfuric acid having a concentration of 10% by weight and having a liquid temperature of 8%.
Pre-etching is performed in which a pit is generated by electrochemically etching the aluminum foil by applying a direct current having a current density of 20 A / dm 2 to the aluminum foil pre-treated in an acidic aqueous solution at 5 ° C. for 200 seconds. Was.

【0013】その後、前段エッチングにより生成された
ピットを化成電圧に適したピット径に拡大させる後段エ
ッチングとして、(表1)に示すように、液温と組成と
濃度をそれぞれ変えたNo.1〜No.13の電解液中で前段
エッチングを行ったアルミニウム箔に電流密度が10A
/dm2の直流電流を400秒間印加して電気化学的に
エッチングを行い、その後、濃度が10重量%で、かつ
液温が60℃の塩酸水溶液中に前記電気化学的エッチン
グが行われたアルミニウム箔を200秒間浸漬して化学
エッチングを行った。
[0013] Thereafter, as post-etching, in which the pits generated by the pre-etching are enlarged to a pit diameter suitable for the formation voltage, as shown in Table 1, the liquid temperature, the composition, and the concentration were changed, respectively. A current density of 10 A was applied to the aluminum foil that was pre-etched in the electrolyte of No. 13.
/ Dm 2 is applied electrochemically by applying a direct current of 400 s for 400 seconds, and then the aluminum is subjected to the electrochemical etching in a hydrochloric acid aqueous solution having a concentration of 10% by weight and a liquid temperature of 60 ° C. The foil was immersed for 200 seconds to perform chemical etching.

【0014】そしてNo.1〜No.13の電解液中で後段エ
ッチングを行ったそれぞれのエッチング箔について、濃
度が8重量%で、かつ液温が90℃のホウ酸水溶液中で
600V化成を行い、その後、これらの各試料について
静電容量と折曲げ強度(1.0mmR、50g荷重、折曲
げ角90度の条件下1往復で1回とする)を測定した。
その測定結果は(表1)に示す。
Each of the etched foils subjected to the second-stage etching in the electrolyte solutions No. 1 to No. 13 was subjected to 600 V chemical conversion in a boric acid aqueous solution having a concentration of 8% by weight and a liquid temperature of 90 ° C. Thereafter, the capacitance and the bending strength of each of these samples (measured once per reciprocation under the conditions of 1.0 mmR, 50 g load, and bending angle of 90 °) were measured.
The measurement results are shown in (Table 1).

【0015】また、(表1)には、No.13の組成であ
る硝酸の代わりに塩酸を用いた比較例1と、No.13と
同じ電気化学エッチング条件で電気化学的にエッチング
を行っただけで、その後の化学エッチングは行わない比
較例2を示しており、そしてこの比較例1と比較例2に
ついても、No.1〜No.13の電解液中で後段エッチング
を行ったそれぞれのエッチング箔と同様、濃度が8重量
%で、かつ液温が90℃のホウ酸水溶液中で600V化
成を行い、その後、静電容量と折曲げ強度(1.0mm
R、50g荷重、折曲げ角90度の条件下1往復で1回
とする)を測定したもので、その測定結果は(表1)に
示している。
Table 1 shows Comparative Example 1 in which hydrochloric acid was used instead of nitric acid having the composition of No. 13, and electrochemical etching was performed under the same electrochemical etching conditions as in No. 13. FIG. 3 shows Comparative Example 2 in which no subsequent chemical etching was performed, and Comparative Examples 1 and 2 were also subjected to post-etching in the electrolyte solutions of Nos. 1 to 13 respectively. As in the case of the foil, a 600 V chemical conversion was performed in a boric acid aqueous solution having a concentration of 8% by weight and a liquid temperature of 90 ° C., and thereafter, the capacitance and the bending strength (1.0 mm
R, a load of 50 g, and a bending angle of 90 degrees under one reciprocation). The measurement results are shown in (Table 1).

【0016】[0016]

【表1】 [Table 1]

【0017】(表1)から明らかなように、後段エッチ
ング工程における電気化学エッチング条件は、硫酸や硝
酸を用いた電解液の濃度が0.5〜9重量%の範囲で、
かつ液温が50〜80℃の範囲において、静電容量、折
曲げ強度ともすぐれたものが得られるものである。
As is clear from Table 1, the electrochemical etching conditions in the latter etching step are such that the concentration of the electrolytic solution using sulfuric acid or nitric acid is in the range of 0.5 to 9% by weight.
In addition, when the liquid temperature is in the range of 50 to 80 ° C., those having excellent capacitance and bending strength can be obtained.

【0018】(実施の形態2)純度が99.98%で、
厚みが100μmのアルミニウム箔を濃度が0.5重量
%の水酸化ナトリウム水溶液中に浸漬して前処理を行
い、次に濃度がそれぞれ10重量%の塩酸と硫酸を含
み、かつ液温が85℃の酸性水溶液中で前処理を行った
アルミニウム箔に電流密度が20A/dm2の直流電流
を200秒間印加してアルミニウム箔を電気化学的にエ
ッチングすることによりピットを生成させる前段エッチ
ングを行った。
(Embodiment 2) The purity is 99.98%,
A pretreatment is performed by immersing an aluminum foil having a thickness of 100 μm in an aqueous solution of sodium hydroxide having a concentration of 0.5% by weight. The pre-etching was performed in which a pit was generated by applying a direct current having a current density of 20 A / dm 2 for 200 seconds to the aluminum foil pretreated in the acidic aqueous solution for 200 seconds to electrochemically etch the aluminum foil.

【0019】その後、前段エッチングにより生成された
ピットを化成電圧に適したピット径に拡大させる後段エ
ッチングとして、濃度が8重量%の硝酸からなる電解液
に(表2)に示すように組成と濃度をそれぞれ変えたN
o.14〜No.22の添加剤を添加した液温70℃の電解
液中で前段エッチングを行ったアルミニウム箔に電流密
度が10A/dm2の直流電流を400秒間印加して電
気化学的にエッチングを行い、その後、濃度が10重量
%で、かつ液温が60℃の塩酸水溶液中に前記電気化学
的エッチングが行われたアルミニウム箔を200秒間浸
漬して化学エッチングを行った。
Then, as a post-stage etching for expanding the pits generated by the pre-stage etching to a pit diameter suitable for the formation voltage, the composition and the concentration as shown in (Table 2) were applied to an electrolyte composed of nitric acid having a concentration of 8% by weight. N which changed each
o. A direct current having a current density of 10 A / dm 2 was applied to the aluminum foil that had been subjected to the first stage etching in an electrolyte solution having a temperature of 70 ° C. to which an additive of No. 14 to No. 22 was added for 400 seconds to electrochemically Etching was performed, and then the aluminum foil subjected to the electrochemical etching was immersed in a hydrochloric acid aqueous solution having a concentration of 10% by weight and a liquid temperature of 60 ° C. for 200 seconds to perform chemical etching.

【0020】そしてNo.14〜No.22の電解液中で後段
エッチングを行ったそれぞれのエッチング箔について、
濃度が8重量%で、かつ液温が90℃のホウ酸水溶液中
で600V化成を行い、その後、これらの各試料につい
て静電容量と折曲げ強度(1.0mmR、50g荷重、折
曲げ角90度の条件下1往復で1回とする)を測定し
た。その測定結果は(表2)に示す。
Then, for each of the etched foils that were subjected to the second-stage etching in the electrolytes of Nos. 14 to 22,
A 600 V chemical conversion was carried out in a boric acid aqueous solution having a concentration of 8% by weight and a liquid temperature of 90 ° C. Thereafter, the capacitance and bending strength (1.0 mmR, 50 g load, bending angle 90 Under the condition of 1 degree). The measurement results are shown in (Table 2).

【0021】[0021]

【表2】 [Table 2]

【0022】(表2)から明らかなように、硫酸あるい
は硝酸の少なくとも1種類以上の電解液に添加される蓚
酸、燐酸、酢酸の少なくとも1種類の添加剤の添加量
は、0.1〜0.5重量%の範囲で添加することによ
り、エッチングの過溶解が効果的に抑制されて、より高
い静電容量を得ることができるものである。
As is clear from Table 2, the amount of at least one additive of oxalic acid, phosphoric acid and acetic acid added to at least one electrolyte solution of sulfuric acid or nitric acid is 0.1 to 0. By adding in the range of 0.5% by weight, overdissolution of etching is effectively suppressed, and a higher capacitance can be obtained.

【0023】(実施の形態3)純度が99.98%で、
厚みが100μmのアルミニウム箔を濃度が0.5重量
%の水酸化ナトリウム水溶液中に浸漬して前処理を行
い、次に濃度がそれぞれ10重量%の塩酸と硫酸を含
み、かつ液温が85℃の酸性水溶液中で前処理を行った
アルミニウム箔に電流密度が20A/dm2の直流電流
を200秒間印加してアルミニウム箔を電気化学的にエ
ッチングすることによりピットを生成させる前段エッチ
ングを行った。
(Embodiment 3) The purity is 99.98%,
A pretreatment is performed by immersing an aluminum foil having a thickness of 100 μm in an aqueous solution of sodium hydroxide having a concentration of 0.5% by weight, and then containing hydrochloric acid and sulfuric acid having a concentration of 10% by weight, respectively, and a liquid temperature of 85 ° C. The pre-etching was performed in which a pit was generated by applying a direct current having a current density of 20 A / dm 2 for 200 seconds to the aluminum foil pretreated in the acidic aqueous solution for 200 seconds to electrochemically etch the aluminum foil.

【0024】その後、前段エッチングにより生成された
ピットを化成電圧に適したピット径に拡大させる後段エ
ッチングとして、濃度が8重量%の硝酸からなる液温7
0℃の電解液中で前段エッチングを行ったアルミニウム
箔に電流密度が10A/dm 2の直流電流を400秒間
印加して電気化学的にエッチングを行い、その後、(表
3)に示すように組成と濃度をそれぞれ変え、かつ液温
が60℃であるNo.23〜No.29の酸性水溶液中に前記
電気化学的エッチングが行われたアルミニウム箔を20
0秒間浸漬して化学エッチングを行った。
After that, it was produced by the pre-etching.
The second step is to enlarge the pit to a pit diameter suitable for the formation voltage.
As a solution, a solution temperature of 7% by weight of nitric acid was used.
Aluminum pre-etched in electrolyte at 0 ° C
Current density of 10A / dm on foil TwoDC current for 400 seconds
To perform electrochemical etching, and then
Change the composition and concentration as shown in 3), and
Is 60 ° C. in an acidic aqueous solution of No. 23 to No. 29.
20 aluminum foils that have been electrochemically etched
Chemical etching was performed by immersion for 0 seconds.

【0025】そして、No.23〜No.29の酸性水溶液中
で化学エッチングを行ったそれぞれのエッチング箔につ
いて、濃度が8重量%で、かつ液温が90℃のホウ酸水
溶液中で600V化成を行い、その後、これらの各試料
について静電容量と折曲げ強度(1.0mmR、50g荷
重、折曲げ角90度の条件下1往復で1回とする)を測
定した。その測定結果は(表3)に示す。
Then, for each of the etched foils subjected to the chemical etching in the acidic aqueous solutions No. 23 to No. 29, a 600 V chemical conversion was carried out in a boric acid aqueous solution having a concentration of 8% by weight and a liquid temperature of 90 ° C. After that, the capacitance and the bending strength (one reciprocation per one cycle under the conditions of 1.0 mmR, 50 g load, and bending angle of 90 degrees) were measured for each of these samples. The measurement results are shown in (Table 3).

【0026】[0026]

【表3】 [Table 3]

【0027】(表3)から明らかなように、化学エッチ
ングを行う塩酸あるいは硫酸からなる酸性水溶液の濃度
は3〜10重量%の範囲において、より高い静電容量を
得ることができるものである。
As is clear from Table 3, when the concentration of the acidic aqueous solution comprising hydrochloric acid or sulfuric acid for chemical etching is in the range of 3 to 10% by weight, a higher capacitance can be obtained.

【0028】なお、この化学エッチングを行う酸性水溶
液は、塩酸と硫酸の混合水溶液を用いても、その濃度が
3〜10重量%の範囲であれば、上記した塩酸あるいは
硫酸の単独の酸性水溶液と同じ効果が得られることを確
認している。
The acidic aqueous solution used for the chemical etching may be a mixed aqueous solution of hydrochloric acid and sulfuric acid as long as its concentration is in the range of 3 to 10% by weight. We have confirmed that the same effect can be obtained.

【0029】[0029]

【発明の効果】以上のように本発明のアルミ電解コンデ
ンサ用電極箔のエッチング方法は、アルミニウム箔を電
気化学的にエッチングすることによりピットを生成させ
る前段エッチング工程と、この前段エッチング工程によ
り生成されたピットを化成電圧に適したピット径に拡大
させる後段エッチング工程とを有し、前記後段エッチン
グ工程は、硫酸あるいは硝酸の少なくとも1種類以上の
電解液中で電気化学的にエッチングを行い、その後、塩
酸、硫酸の少なくとも1種類以上の酸性水溶液中で化学
エッチングを行うようにしたもので、このエッチング方
法によれば、後段エッチング工程において、硫酸あるい
は硝酸の少なくとも1種類以上の電解液中で電気化学的
にエッチングを行うようにしているため、前段エッチン
グ工程で生成された三角錐状のピット形状を円柱でかつ
径の揃ったピット形状にすることができ、そしてこの
後、塩酸あるいは硫酸の少なくとも1種類以上の酸性水
溶液中で化学エッチングを行うようにしているため、化
成電圧に適したピット径まで確実に拡大することがで
き、これにより、次の化成工程において、化成の酸化皮
膜でピットが埋まってしまうということはなくなるた
め、単位面積当たりの静電容量を高めることができるも
のである。
As described above, the method for etching an electrode foil for an aluminum electrolytic capacitor according to the present invention comprises a pre-etching step of forming pits by electrochemically etching an aluminum foil, and a pre-etching step formed by this pre-etching step. A post-etching step of enlarging the pits to a pit diameter suitable for the formation voltage, wherein the post-etching step electrochemically etches in at least one or more of an electrolytic solution of sulfuric acid or nitric acid, According to this etching method, electrochemical etching is performed in an electrolytic solution of at least one of sulfuric acid or nitric acid in a subsequent etching step in an acidic aqueous solution of at least one of hydrochloric acid and sulfuric acid. Etching is performed in the previous stage. Since the triangular pyramid pit shape can be formed into a cylindrical and uniform pit shape, and thereafter, chemical etching is performed in an acidic aqueous solution of at least one kind of hydrochloric acid or sulfuric acid. It is possible to reliably increase the pit diameter to a voltage suitable for the voltage, thereby preventing the pits from being buried with the oxide film formed in the next chemical conversion step, and thereby increasing the capacitance per unit area. Can be done.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 中西 和明 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuaki Nakanishi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】 アルミニウム箔を電気化学的にエッチン
グすることによりピットを生成させる前段エッチング工
程と、この前段エッチング工程により生成されたピット
を化成電圧に適したピット径に拡大させる後段エッチン
グ工程とを有し、前記後段エッチング工程は、硫酸ある
いは硝酸の少なくとも1種類以上の電解液中で電気化学
的にエッチングを行い、その後、塩酸あるいは硫酸の少
なくとも1種類以上の酸性水溶液中で化学エッチングを
行うようにしたアルミ電解コンデンサ用電極箔のエッチ
ング方法。
1. A pre-etching step of generating pits by electrochemically etching an aluminum foil, and a post-etching step of expanding the pits generated in the pre-etching step to a pit diameter suitable for a formation voltage. The post-etching step includes electrochemically etching in at least one or more kinds of electrolytic solution of sulfuric acid or nitric acid, and thereafter performing chemical etching in at least one or more kinds of acidic aqueous solution of hydrochloric acid or sulfuric acid. Method for etching electrode foil for aluminum electrolytic capacitors.
【請求項2】 硫酸あるいは硝酸の少なくとも1種類以
上の電解液の濃度を0.5〜9重量%の範囲に設定し、
かつ液温を50〜80℃の範囲に設定した請求項1に記
載のアルミ電解コンデンサ用電極箔のエッチング方法。
2. The method according to claim 1, wherein the concentration of at least one of sulfuric acid and nitric acid is set in the range of 0.5 to 9% by weight.
The method for etching an electrode foil for an aluminum electrolytic capacitor according to claim 1, wherein the liquid temperature is set in a range of 50 to 80C.
【請求項3】 硫酸あるいは硝酸の少なくとも1種類以
上の電解液に蓚酸、燐酸、酢酸の少なくとも1種類の添
加剤を0.1〜0.5重量%添加するようにした請求項
1または2に記載のアルミ電解コンデンサ用電極箔のエ
ッチング方法。
3. The method according to claim 1, wherein at least one additive of oxalic acid, phosphoric acid, and acetic acid is added in an amount of 0.1 to 0.5% by weight to at least one electrolyte solution of sulfuric acid or nitric acid. The method for etching an electrode foil for an aluminum electrolytic capacitor as described in the above.
【請求項4】 化学エッチングを行う塩酸あるいは硫酸
の少なくとも1種類以上の酸性水溶液の濃度を3〜10
重量%の範囲に設定した請求項1に記載のアルミ電解コ
ンデンサ用電極箔のエッチング方法。
4. The concentration of at least one kind of acidic aqueous solution of hydrochloric acid or sulfuric acid for performing chemical etching is adjusted to 3-10.
2. The method for etching an electrode foil for an aluminum electrolytic capacitor according to claim 1, wherein the etching rate is set in a range of% by weight.
JP9248059A 1997-09-12 1997-09-12 Etching method for electrode foil for aluminum electrolytic capacitor Pending JPH1187186A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9248059A JPH1187186A (en) 1997-09-12 1997-09-12 Etching method for electrode foil for aluminum electrolytic capacitor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9248059A JPH1187186A (en) 1997-09-12 1997-09-12 Etching method for electrode foil for aluminum electrolytic capacitor

Publications (1)

Publication Number Publication Date
JPH1187186A true JPH1187186A (en) 1999-03-30

Family

ID=17172597

Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JPH1187186A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1233432A3 (en) * 2001-02-14 2006-01-11 Matsushita Electric Industrial Co., Ltd. Electrode foil for aluminum electrolytic capacitor and method of manufacturing the same
JP2009105369A (en) * 2007-10-19 2009-05-14 Young Joo Oh Metal capacitor, and manufacturing method therefor
CN105957717A (en) * 2016-05-26 2016-09-21 乳源县立东电子科技有限公司 Multi-stage multi-time pitting method for middle high voltage anode foil
CN106098380A (en) * 2016-05-26 2016-11-09 乳源县立东电子科技有限公司 The hole shape control method of high-voltage anode foil secondary chambering

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1233432A3 (en) * 2001-02-14 2006-01-11 Matsushita Electric Industrial Co., Ltd. Electrode foil for aluminum electrolytic capacitor and method of manufacturing the same
JP2009105369A (en) * 2007-10-19 2009-05-14 Young Joo Oh Metal capacitor, and manufacturing method therefor
JP4664396B2 (en) * 2007-10-19 2011-04-06 ユン・ジョ・オー Metal capacitor and manufacturing method thereof
CN105957717A (en) * 2016-05-26 2016-09-21 乳源县立东电子科技有限公司 Multi-stage multi-time pitting method for middle high voltage anode foil
CN106098380A (en) * 2016-05-26 2016-11-09 乳源县立东电子科技有限公司 The hole shape control method of high-voltage anode foil secondary chambering

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