JP2000282299A - Electrolytic foil having tunnel-shaped pit of uniform depth, electrolytic capacitor using the same as electrode and production of the foil - Google Patents
Electrolytic foil having tunnel-shaped pit of uniform depth, electrolytic capacitor using the same as electrode and production of the foilInfo
- Publication number
- JP2000282299A JP2000282299A JP11086886A JP8688699A JP2000282299A JP 2000282299 A JP2000282299 A JP 2000282299A JP 11086886 A JP11086886 A JP 11086886A JP 8688699 A JP8688699 A JP 8688699A JP 2000282299 A JP2000282299 A JP 2000282299A
- Authority
- JP
- Japan
- Prior art keywords
- foil
- electrolytic
- thickness
- tunnel
- pit
- 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.)
- Granted
Links
- 239000011888 foil Substances 0.000 title claims abstract description 119
- 239000003990 capacitor Substances 0.000 title claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 15
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 32
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 32
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 14
- 230000000149 penetrating effect Effects 0.000 claims description 17
- 239000007864 aqueous solution Substances 0.000 claims description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 abstract description 10
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 abstract description 10
- 238000005530 etching Methods 0.000 description 16
- 238000000034 method Methods 0.000 description 11
- 238000007796 conventional method Methods 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000009826 distribution Methods 0.000 description 4
- 230000005611 electricity Effects 0.000 description 4
- 238000000635 electron micrograph Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
Landscapes
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、電解コンデンサ
ーの電極箔等として利用されるアルミニウム電解箔、そ
の製造方法及びその箔を電極箔とする電解コンデンサー
に関する。より詳細にはアルミニウム箔の両表面に均一
深さのトンネル状ピットを持ち中心部に非貫通層を有す
るアルミニウム電解箔、それを水溶液中における直流電
解により製造する方法及び電極箔とする電解コンデンサ
ーに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminum electrolytic foil used as an electrode foil of an electrolytic capacitor, a method for producing the same, and an electrolytic capacitor using the foil as an electrode foil. More specifically, the present invention relates to an aluminum electrolytic foil having tunnel-like pits of uniform depth on both surfaces of the aluminum foil and having a non-penetrating layer at the center, a method for producing it by DC electrolysis in an aqueous solution, and an electrolytic capacitor as an electrode foil. .
【０００２】[0002]
【従来の技術】アルミ電解コンデンサーは、近年の電子
機器の小型化に伴いますますサイズの小さいものが求め
られている。このアルミ電解コンデンサーには、アルミ
ニウムの電解箔が電極箔として従来より使用されてお
り、中高圧用電解コンデンサー用の電解箔の製造では、
単位面積当たりの静電容量を大きくするために高密度の
立方晶組織を有するアルミニウム原箔を塩素イオンを含
む酸性電解液等の水溶液で直流電解によってエッチング
して、結晶方位の（１００）方向にトンネル状のピット
を形成している。2. Description of the Related Art Aluminum electrolytic capacitors are required to be smaller in size with the recent miniaturization of electronic devices. In this aluminum electrolytic capacitor, aluminum electrolytic foil has been conventionally used as an electrode foil, and in the production of electrolytic foil for medium and high pressure electrolytic capacitors,
In order to increase the capacitance per unit area, an aluminum foil having a cubic structure of high density is etched by direct current electrolysis with an aqueous solution such as an acidic electrolyte solution containing chloride ions, and the direction of the crystal orientation is changed to (100) direction. It forms a tunnel-like pit.
【０００３】このトンネル状ピットの形成においては、
腐蝕開始点のピット数は、そこに印加される電流密度の
大きさに関係すると共に箔の溶解量は電気量にほぼ比例
するものであり、その結果アルミニウム箔の静電容量を
大きくするためには、電解電流密度を大きく設定して高
密度にトンネル状ピットを形成し、かつ印加する電気量
を増大させることにより溶解量を増加させ、箔の表面積
の拡大を図っていた。In the formation of this tunnel-like pit,
The number of pits at the starting point of corrosion is related to the magnitude of the current density applied thereto, and the amount of melting of the foil is almost proportional to the quantity of electricity. As a result, in order to increase the capacitance of the aluminum foil, In this method, a high density of the electrolytic current is set to form tunnel-like pits at a high density, and the amount of applied electricity is increased to increase the amount of dissolution, thereby increasing the surface area of the foil.
【０００４】そして、そのトンネル状ピットの形成過程
については、該ピットの形成は高密度のピットがアルミ
ニウム箔の全面にわたって同時に進行するのではなく、
当初はピットが箔に粗く発生して成長し、その成長が停
止すると別のピットの成長が始まり次第に箔の全面に密
にトンネル状のピットが形成されることが観察されてい
る。[0004] Regarding the process of forming the tunnel-like pits, the formation of the pits is not that high-density pits proceed simultaneously over the entire surface of the aluminum foil.
Initially, it has been observed that pits are coarsely generated in the foil and grow, and when the growth is stopped, the growth of another pit begins, and gradually, dense tunnel-like pits are formed on the entire surface of the foil.
【０００５】この電解箔については、所定の強度を有す
ると共により大きな静電容量を有するものが高性能で望
ましいものであり、そのためには中央部に強度を保持さ
せる可能な限り薄い未エッチング部分を残存させ、しか
もトンネル状ピットについては高密度でかつ深く形成す
ることが必要であると従来考えられていた。そのトンネ
ル状ピットの形成については、従来法では箔に対する直
流電流の印加は図１（ａ）に図示するように時間に対し
一定電流密度の条件でなされていた。For this electrolytic foil, it is desirable that the electrolytic foil has a predetermined strength and a larger capacitance because of its high performance. For this purpose, an unetched portion as thin as possible to maintain the strength is provided at the center. It has been conventionally thought that it is necessary to leave the tunnel-like pits at high density and deep. Regarding the formation of the tunnel-like pits, in the conventional method, a direct current is applied to the foil under a condition of a constant current density with respect to time as shown in FIG.
【０００６】[0006]
【発明が解決しようとする課題】この従来法によって、
より静電容量の大きな電解箔を得ようとすると、印加電
気量を可能な限り増大しようとするあまりエッチングに
よる腐蝕が過度になる。その結果箔の機械的強度の低下
した電解箔が形成されることになり、それを回避するこ
とは困難であった。また、これを改善する電解箔の製造
技術も提案されており、それには例えば図１（ｂ）及び
（ｃ）に図示するように電解電流密度を最大値から漸次
減少させる方法（特開平７−２４９５５０号公報）があ
る。この方法においては、最大電流密度は１０００ｍＡ
／ｃｍ2未満であり、電流印加時間は前記従来法と同様
に８０秒程度となっている。According to the conventional method,
If an attempt is made to obtain an electrolytic foil having a larger capacitance, the amount of applied electricity is increased as much as possible, and the corrosion due to etching becomes excessive. As a result, an electrolytic foil having a reduced mechanical strength of the foil is formed, and it is difficult to avoid this. Further, there has been proposed a technique for manufacturing an electrolytic foil for improving this, for example, a method of gradually decreasing the electrolytic current density from a maximum value as shown in FIGS. 249550). In this method, the maximum current density is 1000 mA
/ Cm 2 , and the current application time is about 80 seconds as in the conventional method.
【０００７】この方法によっても静電容量の大きなもの
を得ようとすると前記した従来法と同様の短所が発現
し、それを完全に回避することは困難であり、その強度
の低下した箔の断面を切断して電子顕微鏡で観察すると
図２（ｂ）のようになっており、この図から、強度の低
下した電解箔のトンネル状ピットは、深さが不揃いで内
側端部はジグザクになっており、所々で両端面から延び
るトンネル状ピットが内通してアルミニウム箔を貫通し
中央部に非貫通層が存在しないことがわかる。[0007] Even if this method is used to obtain a large capacitance, the same disadvantages as those of the above-mentioned conventional method appear, and it is difficult to completely avoid such disadvantages. Fig. 2 (b) shows that the tunnel-shaped pits of the electrolytic foil with reduced strength are irregular in depth and zigzag at the inner end. It can be seen that tunnel-like pits extending from both end surfaces penetrate through the aluminum foil in some places and there is no non-penetrating layer at the center.
【０００８】以上のとおりであるから、本発明は、この
ような問題のない電解箔、その製造方法及びその箔を使
用したアルミニウム電解コンデンサーの発明を提供する
ものである。すなわち、アルミニウム電解箔の機械的強
度を低減させる貫通トンネル状ピットは存在させること
なく、かつ静電容量を可能な限りより大きくすることの
できるトンネル状ピットを形成した電解箔、その製造方
法及びその箔を電極箔とする電解コンデンサーの各発明
を提供することを解決すべき課題とするものであり、目
的とするものである。As described above, the present invention provides an electrolytic foil free from such problems, a method for producing the same, and an aluminum electrolytic capacitor using the foil. That is, there is no penetrating tunnel-like pit for reducing the mechanical strength of the aluminum electrolytic foil, and there is formed an electrolytic foil having a tunnel-like pit capable of making the capacitance as large as possible, a method for producing the same, and a method for producing the same. An object of the present invention is to provide each invention of an electrolytic capacitor using a foil as an electrode foil.
【０００９】[0009]
【課題を解決するための手段】本発明が上記目的を達成
するために採用した手段は、アルミニウム直流電解箔、
その製造方法およびその箔を電極箔とする電解コンデン
サーの各発明であり、その内のアルミニウム直流電解箔
は、アルミニウム箔の両表面に深さが箔厚の３０％以上
であるピットが全ピット数の８０％以上である深さの揃
った、すなわち均一深さのトンネル状ピットを持ち、か
つその中心部に層厚が箔厚の５〜２５％であるピット非
貫通層を有する箔の厚さが７０〜１５０μｍであるとす
るものである。また電解コンデンサーは該アルミニウム
直流電解箔を電極箔とするものである。Means adopted by the present invention to achieve the above object are aluminum DC electrolytic foil,
The invention relates to a method for producing the same and an electrolytic capacitor using the foil as an electrode foil. In the aluminum direct current electrolytic foil, the number of pits having a depth of 30% or more of the foil thickness on both surfaces of the aluminum foil is defined as the total number of pits. Thickness of a foil having a uniform depth, ie, a tunnel-like pit having a uniform depth of not less than 80%, and a pit non-penetrating layer having a layer thickness of 5 to 25% of the foil thickness at the center thereof. Is 70 to 150 μm. The electrolytic capacitor uses the aluminum DC electrolytic foil as an electrode foil.
【００１０】そして、アルミニウム電解箔を製造する方
法は、初期電流密度を１５００ｍＡ／ｃｍ2以上の最大
電流密度とし、その後急激に１００ｍＡ／ｃｍ2以下ま
で低下させる水溶液中における直流電解により、箔厚７
０〜１５０μｍのアルミニウム箔の両表面に均一深さの
トンネル状ピットを持ち、その中心部に層厚が箔厚の５
〜２５％であるピット非貫通層を有するとするものであ
る。[0010] The aluminum electrolytic foil is manufactured by a method in which the initial current density is set to a maximum current density of 1500 mA / cm 2 or more, and thereafter, the foil thickness is reduced to 7 mA / cm 2 by direct current electrolysis in an aqueous solution.
Tunnel-like pits of uniform depth are provided on both surfaces of an aluminum foil of 0 to 150 μm, and the layer thickness is 5 mm at the center of the aluminum foil.
It has a pit non-penetrating layer of about 25%.
【００１１】[0011]
【発明の実施の形態】本発明では、前記した手段、特に
製造方法を採用することにより、直流電解時のエッチン
グ時間を従来法に比し極端に短縮すると同時に、初期電
流密度を過大な最大電流密度とし、そこから急激に１０
０ｍＡ／ｃｍ2以下まで低下させ、それによって優れた
特性を発現する新規な構造の電解箔を提供するものであ
る。その結果得られる新規な構造の電解箔は、図２
（ａ）（実施例１の電解箔）に図示するように深さが揃
った、すなわち均一深さのトンネル状ピットを有し、箔
の厚さ方向の中心部にトンネル状ピットが存在しない非
貫通層を持つ構造となっている。DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, by adopting the above-mentioned means, especially the manufacturing method, the etching time during DC electrolysis is extremely reduced as compared with the conventional method, and at the same time, the initial current density is excessively large. Density, then 10
It is intended to provide an electrolytic foil having a novel structure which is reduced to 0 mA / cm 2 or less, thereby exhibiting excellent characteristics. The resulting electrolytic foil with the new structure is shown in FIG.
(A) As shown in (Electrode foil of Example 1), there is a tunnel-like pit having a uniform depth, that is, having a uniform depth, and no tunnel-like pit is present at the center in the thickness direction of the foil. It has a structure with a through layer.
【００１２】使用するアルミニウム箔については従前の
電解箔材料と同様でよく、その純度は９９．９％以上の
ものが好ましく使用できる。またその箔の厚さについて
も従前の電解箔と同様でよく、それは７０〜１５０μｍ
であり、好ましくは８０〜１２０μｍがよい。そして製
造された電解箔の非貫通層の層厚は箔厚の５〜２５％で
あることが必要であり、好ましくは５〜１５％がよい。
またその非貫通層の厚さは具体的には５〜２５μｍが必
要であり、好ましくは５〜１５μｍがよい。この電解箔
をエッチングする際に用いる水溶液としては、塩酸、又
は塩素イオンを含む硫酸、硝酸もしくはリン酸等が単独
あるいは混合して使用でき、従前のものが制限されるこ
となく使用できる。The aluminum foil to be used may be the same as the conventional electrolytic foil material, and preferably has a purity of 99.9% or more. Further, the thickness of the foil may be the same as that of the conventional electrolytic foil, and is 70 to 150 μm.
And preferably 80 to 120 μm. The thickness of the non-penetrating layer of the manufactured electrolytic foil needs to be 5 to 25% of the foil thickness, preferably 5 to 15%.
In addition, the thickness of the non-penetrating layer specifically needs to be 5 to 25 μm, and preferably 5 to 15 μm. As an aqueous solution used for etching the electrolytic foil, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or the like containing chloride ions can be used alone or in combination, and conventional ones can be used without limitation.
【００１３】エッチングの際の電流密度については、前
記したとおり初期電流密度を最大電流密度とし、その後
急激に１００ｍＡ／ｃｍ2まで低減させることが必要で
ある。その際には前記の優れた性質を有する新規な構造
の電解箔を得るには初期電流密度は１５００〜７０００
ｍＡ／ｃｍ2とすることが必要であり、好ましくは３０
００〜６０００ｍＡ／ｃｍ2とするのがよい。この初期
電流密度を７０００ｍＡ／ｃｍ2以下とするのは、それ
を超えると箔の腐蝕表面の脱落が生じるので、それを避
けるためである。また初期電流密度が１５００ｍＡ以下
であるとピット数の不足を招き、静電容量が極端に低下
するためである。なお、ここにおける初期電流密度と
は、エッチング槽内で原箔に電流を印加し電解が開始す
る時点での電流密度であるRegarding the current density at the time of etching, it is necessary to set the initial current density to the maximum current density as described above, and then rapidly reduce the current density to 100 mA / cm 2 . In this case, in order to obtain an electrolytic foil having a novel structure having the above excellent properties, the initial current density is 1500 to 7000.
mA / cm 2 , preferably 30 mA / cm 2.
It is good to be 00-6000 mA / cm 2 . The reason why the initial current density is set to 7000 mA / cm 2 or less is that if the initial current density exceeds 7000 mA / cm 2 , the corroded surface of the foil will fall off. If the initial current density is 1500 mA or less, the number of pits becomes insufficient, and the capacitance is extremely reduced. Note that the initial current density here is the current density at the time when the current is applied to the original foil in the etching tank and the electrolysis starts.
【００１４】そして、急激に１００ｍＡ／ｃｍ2以下ま
でに低減させるに要する時間は１０〜３０秒がよく、好
ましくは１５〜２０秒がよい。このようにエッチング終
了時に電流密度を急激に１００ｍＡ／ｃｍ2以下とする
のは、このようにしないと短いピットが形成されやすい
ためである。また電解時間を先の範囲とするのは、それ
が３０秒を超えると貫通孔を形成する長いピットが形成
されやすく、電解箔の機械的強度が低下するためであ
る。The time required to rapidly reduce the current to 100 mA / cm 2 or less is preferably 10 to 30 seconds, and more preferably 15 to 20 seconds. The reason why the current density is rapidly reduced to 100 mA / cm 2 or less at the end of the etching is that short pits are likely to be formed otherwise. The reason for setting the electrolysis time to the above range is that if the electrolysis time exceeds 30 seconds, long pits forming a through hole are easily formed, and the mechanical strength of the electrolysis foil is reduced.
【００１５】さらに、印加する電流密度の減衰形態につ
いては、初期の最大電流密度から急激に１００ｍＡ／ｃ
ｍ2以下まで低減する形態であれば特に制約はない。な
お従前の電解箔製造用のエッチングにおいて印加する電
流密度の形態は、図１（ａ）に示す一定電流密度となっ
ており、本発明で印加するそれとは非常に異なったもの
となっている。またその際のエッチングに要する時間は
８０秒程度であり、本発明と比較するとはるかに長い時
間を要するものとなっている。Further, with respect to the decay mode of the applied current density, the current density rapidly decreases from the initial maximum current density to 100 mA / c.
There is no particular limitation as long as the form is reduced to m 2 or less. The form of the current density applied in the conventional etching for manufacturing the electrolytic foil is a constant current density shown in FIG. 1A, which is very different from that applied in the present invention. The time required for the etching at that time is about 80 seconds, which is much longer than that of the present invention.
【００１６】本発明の電解箔製造における電流印加時間
の調節については、箔のエッチングが水溶液中で対向す
る電極間を通過する間に行われるものであるから、その
電極の長さあるいは箔の通過速度等を調節することによ
り１０〜３０秒以内とすることが可能である。また電流
密度の調節については、対向する電極間に箔が存在する
間にエッチングが実施されることから、対向する電極の
表面積や距離を調節することによって行うことが可能で
ある。電極の表面積を調節する方法としては、各種の手
段が採用でき特に制限されることはなく、例えば電極の
一部を打ち抜き対向する電極の表面積を変化させる構造
や電極表面形状を変える方法等がある。The adjustment of the current application time in the production of the electrolytic foil of the present invention is performed while the foil is etched while passing between opposed electrodes in an aqueous solution. By adjusting the speed and the like, it is possible to set the time within 10 to 30 seconds. In addition, the current density can be adjusted by adjusting the surface area and the distance of the opposing electrodes since the etching is performed while the foil exists between the opposing electrodes. As a method of adjusting the surface area of the electrode, various means can be adopted and there is no particular limitation. For example, there is a method of punching a part of the electrode and changing the surface area of the opposing electrode, a method of changing the electrode surface shape, and the like. .
【００１７】[0017]
【実施例】以下に、本発明の実施例及び比較例を記載
し、本発明の特徴点及び卓越した効果を具体的に示す
が、本発明は、この実施例に限定されるものではなく特
許請求の範囲の記載に基づいて把握されるものであるこ
とはいうまでもない。EXAMPLES Examples and comparative examples of the present invention will be described below to specifically show the features and outstanding effects of the present invention. However, the present invention is not limited to these examples, but includes patents. It goes without saying that the information is grasped based on the description in the claims.
【００１８】（実施例１及び従来例）純度９９．９８％
及び厚さ１０６μｍのアルミニウム原箔を、塩酸濃度１
ｍｏｌ／Ｌ、硫酸濃度３ｍｏｌ／Ｌの溶液中で表１に示
す条件によってエッチングを行った。すなわち、本発明
に該当する実施例１では初期電流密度４０００ｍＡ／ｃ
ｍ2、最終電流密度１００ｍＡ／ｃｍ2、エッチング時間
２０秒で電解を行った。また従来技術に該当する従来例
では初期電流密度３５０ｍＡ／ｃｍ2一定、エッチング
時間８０秒で電解を行った。(Example 1 and Conventional Example) Purity 99.98%
And an aluminum foil having a thickness of 106 μm, a hydrochloric acid concentration of 1
The etching was performed under the conditions shown in Table 1 in a solution having a mol / L and sulfuric acid concentration of 3 mol / L. That is, in Example 1 corresponding to the present invention, the initial current density was 4000 mA / c.
Electrolysis was performed at m 2 , a final current density of 100 mA / cm 2 , and an etching time of 20 seconds. In the conventional example corresponding to the prior art, the electrolysis was performed at an initial current density of 350 mA / cm 2 and an etching time of 80 seconds.
【００１９】そして、得られた電解箔の性質及び断面構
造は表１及び図２（ａ）．（ｂ）に示すとおりである。
この結果から、本発明においては、従来技術に比し形成
されたトンネル状ピットは深さが深く、かつ揃ってお
り、また箔の中心部に薄いピット非貫通層が形成されて
おり機械的強度も高いことがわかる。さらに静電容量も
実施例の電解箔の方が従来例の電解箔に比し優れている
ことがわかる。The properties and sectional structure of the obtained electrolytic foil are shown in Table 1 and FIG. It is as shown in (b).
From these results, in the present invention, the tunnel-like pits formed in comparison with the prior art are deeper and more uniform, and a thin pit non-penetrating layer is formed at the center of the foil, and the mechanical strength is higher. Is also high. Further, it can be seen that the electrolytic foil of the example is more excellent in capacitance than the electrolytic foil of the conventional example.
【００２０】また、得られた電解箔のピットの深さの詳
細な分布状態については、表３に記載するとおりであ
り、この表から従来例ではピットの深さが０〜５０μｍ
を越えた範囲の広範囲に分布しているのがわかる。それ
に対し、実施例１では４０〜５０μｍの範囲に８８％が
存在し、きわめて限られた範囲にほとんどが存在してお
り、そのピットのほとんどはいずれも深くて、かつ深さ
が揃ってるいることがわかる。The detailed distribution of the pit depth of the obtained electrolytic foil is as shown in Table 3. From this table, it can be seen from the table that the pit depth is 0 to 50 μm in the conventional example.
It can be seen that it is distributed over a wide area beyond the range. On the other hand, in Example 1, 88% existed in the range of 40 to 50 μm, most existed in an extremely limited range, and most of the pits were all deep and uniform in depth. I understand.
【００２１】なお、深さ分布の測定法については、エポ
キシ樹脂に埋め込まれた電解箔試料をウルトラマイクロ
トーム（ＲＭＣ社製）で電解箔の表面を深さ方向にμｍ
単位でダイヤモンドナイフにより研削し、そのときの研
削面の表面をＳＥＭに取り、それを画像解析装置（東洋
紡社製Ｖ１０）にかけトンネル密度を算出する。ついで
その箔表面からの研削深さとトンネル密度との関係から
トンネル深さの分布を算出する。As for the method of measuring the depth distribution, an electrolytic foil sample embedded in an epoxy resin was coated with an ultramicrotome (manufactured by RMC) to measure the surface of the electrolytic foil in a depth direction of μm.
The unit is ground with a diamond knife, the surface of the ground surface at that time is taken with an SEM, and the surface is applied to an image analyzer (V10 manufactured by Toyobo Co., Ltd.) to calculate the tunnel density. Next, the distribution of the tunnel depth is calculated from the relationship between the grinding depth from the foil surface and the tunnel density.
【００２２】[0022]
【表１】 [Table 1]
【００２３】（実施例２及び比較例）純度９９．９８％
及び厚さ１０６μｍのアルミニウム原箔を、塩酸濃度１
ｍｏｌ／Ｌ、硫酸濃度３ｍｏｌ／Ｌの水溶液中で、初期
電流密度４０００ｍＡ／ｃｍ 2、最終電流密度１００ｍ
Ａ／ｃｍ2で、表２に示すように電解時間を変化させ
て、実施例１と同様にエッチングを行った。得られた電
解箔の特性及び断面構造は、表３及び図３、４に示すと
おりである。この結果からエッチング時間が２０秒以下
で特に良好な特性を示していることがわかる。またエッ
チング時間が３０秒を越えるとピット深さが深くなり、
両面からのピットがつながってしまい非貫通層がなくな
ることから電解箔の機械的強度が低下する。(Example 2 and Comparative Example) Purity 99.98%
And an aluminum foil having a thickness of 106 μm, a hydrochloric acid concentration of 1
mol / L, sulfuric acid concentration 3mol / L aqueous solution
Current density 4000 mA / cm Two, Final current density 100m
A / cmTwoThen, change the electrolysis time as shown in Table 2.
Then, etching was performed in the same manner as in Example 1. Obtained electricity
The properties and cross-sectional structure of the unwrapped foil are shown in Table 3 and FIGS.
It is a cage. From this result, the etching time is less than 20 seconds
It can be seen that this shows particularly good characteristics. Also
If the ching time exceeds 30 seconds, the pit depth becomes deeper,
Pits from both sides are connected and there is no non-penetrating layer
Therefore, the mechanical strength of the electrolytic foil decreases.
【００２４】そして、得られた電解箔のピットの深さの
詳細な分布状態については、実施例１と同様に表３に記
載しており、実施例２ではピットの深さが２０〜３０μ
ｍと３０〜４０μｍの範囲にそれぞれ約４５％のピット
が存在し、この両範囲に合わせて約９０％のピットが存
在している。それに対し、比較例では５０μｍ以上の深
さのピットが５０％以上存在し、ピットが深くなり過ぎ
ており、図４に示す非貫通層が存在しない結果と一致し
ている。The detailed distribution of the pit depth of the obtained electrolytic foil is described in Table 3 as in Example 1. In Example 2, the pit depth is 20 to 30 μm.
Approximately 45% of the pits exist in the range of m and 30 to 40 μm, and approximately 90% of the pits coincide with both ranges. On the other hand, in the comparative example, pits having a depth of 50 μm or more exist in 50% or more, and the pits are too deep, which is consistent with the result shown in FIG. 4 in which the non-penetrating layer does not exist.
【００２５】[0025]
【表２】 [Table 2]
【００２６】[0026]
【表３】 [Table 3]
【００２７】（実施例３）純度９９．９８％及び厚さ１
０６μｍのアルミニウム原箔を、塩酸濃度１ｍｏｌ／
ｌ、硫酸濃度３ｍｏｌ／ｌの溶液中で、図５に図示する
各種初期電流密度で実施例１と同様にエッチングを行っ
た。得られた電解箔の３８５Ｖ化成時の静電容量は図５
に示すとおりであり、初期電流密度が３０００〜６００
０ｍＡ／ｃｍ 2の範囲で高性能の静電容量の電解箔が取
得できることがわかる。(Example 3) Purity 99.98% and thickness 1
06 µm aluminum foil was treated with a hydrochloric acid concentration of 1 mol /
1, in a solution having a sulfuric acid concentration of 3 mol / l, as shown in FIG.
Etching was performed in the same manner as in Example 1 at various initial current densities.
Was. The capacitance of the obtained electrolytic foil during formation at 385 V is shown in FIG.
And the initial current density is 3000 to 600
0mA / cm TwoElectrolytic foil with high performance capacitance
It can be seen that it can be obtained.
【００２８】[0028]
【発明の効果】本発明では、電解箔におけるトンネル状
ピットは内部深くまで高密度で、かつ深さが揃ったもの
が形成されており、そのため箔の中心部にはトンネル状
ピット不存在の非貫通層を存在させることができる。そ
の結果本発明においては、機械的強度を低減させること
なく高静電容量の電解箔を提供可能とするという卓越し
た効果を奏することができる。According to the present invention, the tunnel-shaped pits in the electrolytic foil are formed to have a high density and a uniform depth to the inside, so that the center of the foil has no tunnel-shaped pits. A penetrating layer can be present. As a result, in the present invention, an excellent effect that an electrolytic foil having a high capacitance can be provided without reducing the mechanical strength can be obtained.
【図１】従来技術及び改良先行技術におけるエッチング
時の電流密度と印加時間との関係を示す図。FIG. 1 is a diagram showing the relationship between current density and application time during etching in the prior art and the improved prior art.
【図２】本発明等の電解箔断面の電子顕微鏡写真であ
り、（ａ）は実施例１の電解箔、（ｂ）は従来例の電解
箔である。FIGS. 2A and 2B are electron micrographs of a cross section of an electrolytic foil according to the present invention, in which FIG. 2A shows an electrolytic foil of Example 1 and FIG. 2B shows an electrolytic foil of a conventional example.
【図３】実施例２で得た電解箔断面の電子顕微鏡写真。FIG. 3 is an electron micrograph of a cross section of an electrolytic foil obtained in Example 2.
【図４】比較例で得た電解箔断面の電子顕微鏡写真。FIG. 4 is an electron micrograph of a cross section of an electrolytic foil obtained in a comparative example.
【図５】実施例３の実験の結果等を示す図。FIG. 5 is a diagram showing the results of experiments in Example 3;
Claims (7)
３０％以上であるピットが全ピット数の８０％以上であ
る均一深さのトンネル状ピットを持ち、かつその中心部
に層厚が箔厚の５〜２５％であるピット非貫通層を有す
る箔の厚さが７０〜１５０μｍであるアルミニウム直流
電解箔。1. A pit having a depth of 30% or more of the foil thickness has a tunnel-like pit having a uniform depth of 80% or more of the total number of pits on both surfaces of the aluminum foil, and a layer thickness at the center thereof. Is an aluminum direct current electrolytic foil having a thickness of 70 to 150 μm having a pit non-penetrating layer having a thickness of 5 to 25% of the foil thickness.
非貫通層の層厚が箔厚の５〜１５％である請求項１記載
の直流電解箔。2. The DC electrolytic foil according to claim 1, wherein the foil thickness is 80 to 120 μm, and the layer thickness of the pit non-penetrating layer is 5 to 15% of the foil thickness.
ある請求項１又は２記載の電解箔。3. The electrolytic foil according to claim 1, wherein the pit non-penetrating layer has a layer thickness of 5 to 25 μm.
３０％以上であるピットが全ピット数の８０％以上であ
る均一深さのトンネル状ピットを持ち、かつその中心部
に層厚が箔厚の５〜２５％であるピット非貫通層を有す
る箔の厚さが７０〜１５０μｍであるアルミニウム直流
電解箔を電極箔とする電解コンデンサー。4. A pit having a depth of 30% or more of the foil thickness has a tunnel-like pit having a uniform depth of 80% or more of the total number of pits on both surfaces of the aluminum foil, and a layer thickness at the center thereof. An electrolytic capacitor using an aluminum DC electrolytic foil having a thickness of 70 to 150 μm having a pit non-penetrating layer having a thickness of 5 to 25% of the foil thickness as an electrode foil.
非貫通層の層厚が箔厚の５〜１５％である請求項４記載
の電解コンデンサー。5. The electrolytic capacitor according to claim 4, wherein the foil thickness is 80 to 120 μm, and the layer thickness of the pit non-penetrating layer is 5 to 15% of the foil thickness.
上の最大電流密度とし、その後急激に１００ｍＡ／ｃｍ
2以下まで低下させる水溶液中における直流電解によ
り、箔厚７０〜１５０μｍのアルミニウム箔の両表面に
均一深さのトンネル状ピットを持ち、その中心部に層厚
が箔厚の５〜２５％であるピット非貫通層を有するアル
ミニウム直流電解箔を製造する方法。6. An initial current density is set to a maximum current density of 1500 mA / cm 2 or more, and then rapidly increased to 100 mA / cm 2.
Due to direct current electrolysis in an aqueous solution reduced to 2 or less, aluminum foil having a foil thickness of 70 to 150 μm has tunnel-like pits of uniform depth on both surfaces, and the layer thickness is 5 to 25% of the foil thickness at the center. A method for producing an aluminum DC electrolytic foil having a pit non-penetrating layer.
低下させる所要時間を１０〜３０秒とせしめた請求項６
記載のアルミニウ直流電解箔を製造する方法。7. The time required to reduce the current density to 100 mA / cm 2 or less is set to 10 to 30 seconds.
A method for producing the aluminum direct current electrolytic foil according to the above.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08688699A JP3381657B2 (en) | 1999-03-29 | 1999-03-29 | Electrolytic foil having tunnel-like pits of uniform depth, electrolytic capacitor using the same as an electrode, and method for producing the foil |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08688699A JP3381657B2 (en) | 1999-03-29 | 1999-03-29 | Electrolytic foil having tunnel-like pits of uniform depth, electrolytic capacitor using the same as an electrode, and method for producing the foil |
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| Publication Number | Publication Date |
|---|---|
| JP2000282299A true JP2000282299A (en) | 2000-10-10 |
| JP3381657B2 JP3381657B2 (en) | 2003-03-04 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109791843A (en) * | 2016-09-30 | 2019-05-21 | 日本贵弥功株式会社 | Electrode foil and electrolytic capacitor |
| JP7442099B2 (en) | 2019-02-28 | 2024-03-04 | パナソニックＩｐマネジメント株式会社 | Electrode foil for electrolytic capacitors, electrolytic capacitors and their manufacturing method |
-
1999
- 1999-03-29 JP JP08688699A patent/JP3381657B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109791843A (en) * | 2016-09-30 | 2019-05-21 | 日本贵弥功株式会社 | Electrode foil and electrolytic capacitor |
| JP7442099B2 (en) | 2019-02-28 | 2024-03-04 | パナソニックＩｐマネジメント株式会社 | Electrode foil for electrolytic capacitors, electrolytic capacitors and their manufacturing method |
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| JP3381657B2 (en) | 2003-03-04 |
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