JPH0471214A - Aluminum electrode for electrolytic capacitor and manufacture thereof - Google Patents
Aluminum electrode for electrolytic capacitor and manufacture thereofInfo
- Publication number
- JPH0471214A JPH0471214A JP18483190A JP18483190A JPH0471214A JP H0471214 A JPH0471214 A JP H0471214A JP 18483190 A JP18483190 A JP 18483190A JP 18483190 A JP18483190 A JP 18483190A JP H0471214 A JPH0471214 A JP H0471214A
- Authority
- JP
- Japan
- Prior art keywords
- metal
- thin film
- aluminum
- electrode
- gas
- 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
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 38
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 38
- 239000003990 capacitor Substances 0.000 title claims abstract description 27
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 229910052751 metal Inorganic materials 0.000 claims abstract description 40
- 239000002184 metal Substances 0.000 claims abstract description 40
- 239000010409 thin film Substances 0.000 claims abstract description 28
- 239000007789 gas Substances 0.000 claims abstract description 22
- 238000001704 evaporation Methods 0.000 claims abstract description 17
- 230000008020 evaporation Effects 0.000 claims abstract description 12
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000010936 titanium Substances 0.000 claims abstract description 10
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 10
- 229910052715 tantalum Inorganic materials 0.000 claims abstract description 9
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims abstract description 9
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 9
- 239000010937 tungsten Substances 0.000 claims abstract description 9
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 8
- 239000010955 niobium Substances 0.000 claims abstract description 8
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims abstract description 8
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 7
- 229910052726 zirconium Inorganic materials 0.000 claims abstract description 7
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims abstract 3
- 238000000034 method Methods 0.000 claims description 15
- 238000007740 vapor deposition Methods 0.000 claims description 15
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 6
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 6
- 150000002430 hydrocarbons Chemical class 0.000 claims description 5
- 239000004215 Carbon black (E152) Substances 0.000 claims description 4
- 229930195733 hydrocarbon Natural products 0.000 claims description 4
- 239000000463 material Substances 0.000 abstract description 20
- 238000010891 electric arc Methods 0.000 abstract description 8
- 229910021645 metal ion Inorganic materials 0.000 abstract description 8
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 6
- 239000002245 particle Substances 0.000 abstract description 4
- 239000012495 reaction gas Substances 0.000 abstract description 3
- 238000005121 nitriding Methods 0.000 abstract description 2
- JMANVNJQNLATNU-UHFFFAOYSA-N oxalonitrile Chemical compound N#CC#N JMANVNJQNLATNU-UHFFFAOYSA-N 0.000 abstract 2
- 239000010408 film Substances 0.000 description 19
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 150000002739 metals Chemical class 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000003763 carbonization Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 229910052736 halogen Inorganic materials 0.000 description 3
- 150000002367 halogens Chemical class 0.000 description 3
- 239000011261 inert gas Substances 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 150000004767 nitrides Chemical class 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 238000000576 coating method Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 230000036571 hydration Effects 0.000 description 2
- 238000006703 hydration reaction Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 239000013077 target material Substances 0.000 description 2
- 238000005019 vapor deposition process Methods 0.000 description 2
- FLDCSPABIQBYKP-UHFFFAOYSA-N 5-chloro-1,2-dimethylbenzimidazole Chemical compound ClC1=CC=C2N(C)C(C)=NC2=C1 FLDCSPABIQBYKP-UHFFFAOYSA-N 0.000 description 1
- 239000001741 Ammonium adipate Substances 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- UQZIWOQVLUASCR-UHFFFAOYSA-N alumane;titanium Chemical compound [AlH3].[Ti] UQZIWOQVLUASCR-UHFFFAOYSA-N 0.000 description 1
- 235000019293 ammonium adipate Nutrition 0.000 description 1
- 239000010405 anode material Substances 0.000 description 1
- 150000001722 carbon compounds Chemical class 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000000541 cathodic arc deposition Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010574 gas phase reaction Methods 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- VEALVRVVWBQVSL-UHFFFAOYSA-N strontium titanate Chemical compound [Sr+2].[O-][Ti]([O-])=O VEALVRVVWBQVSL-UHFFFAOYSA-N 0.000 description 1
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 1
Abstract
Description
この発明は電解コンデンサの電極に用いられるアルミニ
ウム電極およびその製造方法に関する。The present invention relates to an aluminum electrode used as an electrode of an electrolytic capacitor and a method for manufacturing the same.
電解コンデンサは、小型、大容量、安価で整流出力の平
滑用などの用途に用いられ、各種の電気、電子機器の重
要な構成要素の一つである。
電解コンデンサは、一般にアルミニウム等の絶縁性酸化
皮膜が形成され得る、いわゆる弁金属を少なくとも陽極
に用い、前記絶縁性酸化皮膜を誘電体層として、集電用
の陰極電極との間にセパレータに保持された電解液を介
在させてコンデンサ素子を作成し、これを密閉容器内に
収納して構成される。
電極材料は前述したように、アルミニウムをはじめ、タ
ンタル、ニオブ、チタンなど弁金属であれば、理論上使
用が可能である。しかしながら現実には、材料の経済的
理由や、誘電体酸化皮膜層の形成性において、アルミニ
ウムおよびタンタルが実用化されている。
ところで、電解コンデンサは弁作用による絶縁酸化皮膜
を誘電体層として用いる。この誘電体酸化皮膜層は極め
て薄いので、電極の単位面積あたりの静電容量値を高く
することができ、電解コンデンサの特徴の一つである小
型大容量の製品が実現できる。
しかしながら、最近は電気機器の小型化がより促進され
、電解コンデンサもこれら機器に組み込むために従前に
ました小型化が求められている。
電解コンデンサを小型化するためには、誘電体酸化皮膜
層の厚さを減らすか、面積を拡大することが考えられる
。しかし誘電体酸化皮膜層の厚さを減らすと、所望の耐
圧が得られない。このため従来から電極表面を拡面化の
ためエツチング処理を施すことが行われてきた。
この表面積を拡大する技術は、現在では高度に洗練され
ているが、この技術のみによって電解コンデンサの静電
容量を飛躍的に増加させるのは次第に困難になりつつあ
る。
また陰極側電極についても、陽極側電極と同種の弁金属
が使用されることが多いが、この陰極側電極表面には、
自然酸化による酸化皮膜層が表面に形成される。この傾
向はアルミニウムにおいて特に顕著である。そしてこの
自然酸化皮膜は極めて薄い絶縁層となるため、陰極側に
も静電容量が形成され、電解コンデンサは、陽極側の静
電容量および陰極側の静電容量が直列に接続された合成
容量となり、陽極側電極の静電容量より低い値となる。
この影響を少なくするためには、陽極側の静電容量値に
比べ陰極側の静電容量値を著しく高くすれば、陰極側の
静電容量による影響は殆ど無視できることになるが、低
電圧用の電解コンデンサの陽極の単位面積あたりの静電
容量は相当に高い水準にあり、これをより高めるのは困
難で、合成容量による静電容量値の低下は免れ得ない。
そこで静電容量を増大させるためには、電極表面に形成
された誘電体酸化皮膜の比誘電率を上げることが考えら
れる。しかし通常は、陽極材料である弁金属の酸化物固
有の比誘電率によってその値は決まってしまい、変更の
余地は殆どない。
電極表面の誘電体酸化皮膜層の被誘電率を上げるために
は、基材である電極金属の酸化物とは異なる高い比誘電
率を持つ物質を、電極の絶縁酸化皮膜の一部もしくは全
部に代えて形成することが考えられる。
このような基材と異なる物質を基材上に形成するものと
して、例えば特開平１−１７５７１４号公報にあるよう
に、誘電体フィルム表面に蒸着、スパッタリング、プラ
ズマＣＶＤなどの手法によってチタン酸ストロンチウム
の薄膜を形成するもの、特開昭５９−１６７００９号公
報のように不活性ガス中で金属を蒸着した後化成処理を
行うもの、特開昭６３３０６６１４号公報のごとくイオ
ンブレーティングによりアルミニウムーチタン合金層を
形成し陽極酸化（化成）処理を行うものなどが提案され
ている。
しかしながら、前述した方法では、アルミニウム表面へ
の薄膜の密着性は必ずしも十分ではなく、特に蒸着技術
を改良してより優れた電解コンデンサ用アルミニウム陽
極電極を製造する余地が残されていた。このようなもの
として、例えば本発明者による特願平１−１３９３２７
号ように、アルミニウム電極表面へチタンを陰極アーク
蒸着法によって薄膜を形成するものなどがある。
この陰極アーク蒸着法による異種金属の形成は、電極の
静電容量の増加と共に、薄膜の密着性を向上させること
ができる。しかしながら電解コンデンサは、より一層の
小型化、大容量化を求められている。Electrolytic capacitors are small, large-capacity, and inexpensive, and are used for purposes such as smoothing rectified output, and are one of the important components of various electrical and electronic devices. Electrolytic capacitors generally use a so-called valve metal such as aluminum on which an insulating oxide film can be formed, at least as an anode, and the insulating oxide film is used as a dielectric layer and is held in a separator between it and a cathode electrode for current collection. A capacitor element is created by interposing the electrolyte solution, and the capacitor element is housed in a sealed container. As mentioned above, any valve metal such as aluminum, tantalum, niobium, titanium, etc. can be used as the electrode material in theory. However, in reality, aluminum and tantalum have been put into practical use due to material economical reasons and ease of forming a dielectric oxide film layer. By the way, electrolytic capacitors use an insulating oxide film with valve action as a dielectric layer. Since this dielectric oxide film layer is extremely thin, it is possible to increase the capacitance value per unit area of the electrode, making it possible to realize a small and large-capacity product, which is one of the characteristics of electrolytic capacitors. However, recently, electrical equipment has become more compact, and electrolytic capacitors are required to be made smaller than before in order to be incorporated into these equipment. In order to downsize electrolytic capacitors, it is conceivable to reduce the thickness of the dielectric oxide film layer or to increase its area. However, if the thickness of the dielectric oxide film layer is reduced, the desired breakdown voltage cannot be obtained. For this reason, etching treatment has conventionally been performed to enlarge the electrode surface. Although this technique of increasing surface area is now highly sophisticated, it is becoming increasingly difficult to dramatically increase the capacitance of electrolytic capacitors using this technique alone. Also, the same type of valve metal as the anode electrode is often used for the cathode side electrode, but the surface of this cathode side electrode is
An oxide film layer is formed on the surface due to natural oxidation. This tendency is particularly noticeable in aluminum. Since this natural oxide film becomes an extremely thin insulating layer, capacitance is also formed on the cathode side, and an electrolytic capacitor is a composite capacitor in which the anode side capacitance and the cathode side capacitance are connected in series. This is a value lower than the capacitance of the anode side electrode. In order to reduce this effect, if the capacitance value on the cathode side is made significantly higher than the capacitance value on the anode side, the effect of the capacitance on the cathode side can be almost ignored. The electrostatic capacitance per unit area of the anode of an electrolytic capacitor is at a considerably high level, and it is difficult to further increase this, and a decrease in the capacitance value due to the combined capacitance is inevitable. Therefore, in order to increase the capacitance, it is possible to increase the dielectric constant of the dielectric oxide film formed on the electrode surface. However, normally, the value is determined by the specific dielectric constant of the oxide of the valve metal that is the anode material, and there is little room for change. In order to increase the dielectric constant of the dielectric oxide film layer on the electrode surface, a substance with a high dielectric constant different from the oxide of the electrode metal, which is the base material, is applied to part or all of the electrode's insulating oxide film. It is conceivable to form it instead. In order to form a substance different from the base material on the base material, for example, as disclosed in Japanese Patent Application Laid-open No. 1-175714, strontium titanate is formed on the surface of the dielectric film by methods such as vapor deposition, sputtering, and plasma CVD. Those that form a thin film, those that perform chemical conversion treatment after vapor deposition of metal in an inert gas as in JP-A-59-167009, and those that form an aluminum-titanium alloy layer by ion blating as in JP-A-63306614. It has been proposed to form an anodic oxidation (chemical conversion) treatment. However, with the method described above, the adhesion of the thin film to the aluminum surface is not necessarily sufficient, and there is still room to improve the vapor deposition technique to produce a better aluminum anode electrode for an electrolytic capacitor. As such, for example, Japanese Patent Application No. 1-139327 by the present inventor
There is a method in which a thin film of titanium is formed on the surface of an aluminum electrode by cathodic arc evaporation. Formation of dissimilar metals by this cathodic arc evaporation method can increase the capacitance of the electrode and improve the adhesion of the thin film. However, electrolytic capacitors are required to be further miniaturized and have a larger capacity.
そこでこの発明は、電解コンデンサの電極となる高純度
アルミニウムの表面に、より高い誘電率を持ち、しかも
特性上安定度の良い薄膜を形成することで、電極単位面
積あたりの静電容量が大きく、しかも信頼性の高い電解
コンデンサ用電極を得ることを目的としている。
またこの発明の他の目的は、上記の電解コンデンサ用電
極を形成するのに好適な製造方法を得ることにある。Therefore, this invention aims to form a thin film with a higher dielectric constant and stable characteristics on the surface of high-purity aluminum, which becomes the electrode of an electrolytic capacitor, thereby increasing the capacitance per unit area of the electrode. Moreover, the aim is to obtain highly reliable electrodes for electrolytic capacitors. Another object of the present invention is to obtain a manufacturing method suitable for forming the above electrode for an electrolytic capacitor.
この発明は、チタン、バナジウム、ニオブ、タンタル、
ジルコニウム、タングステンから選ばれたいずれか金属
の炭化物と窒化物との複合物（以下炭窒化物という）が
この発明の目的に適合した薄膜を形成することに着目し
たもので、この発明の電解コンデンサ用電極は、高純度
アルミニウム表面に、チタン、バナジウム、ニオブ、タ
ンタル、ジルコニウム、タングステンのいずれかの金属
の炭窒化物からなる薄膜層を形成したことを特徴として
いる。
またこの発明は、これら金属の炭窒化物の薄膜をアルミ
ニウム表面に形成する手段として、陰極アーク蒸着法を
用いることも特徴としている。
この発明によれば、被処理材料としては通常の電解コン
デンサの電極に用いる高純度の箔状あるいは板状のアル
ミニウムを用いることができる。
このアルミニウム表面は、あらかじめ脱脂処理等にをよ
り表面を清浄化しておく。またアルミニウム表面はエツ
チング処理を施しても良いし、ブレーンのままであって
も使用可能である。
形成される炭窒化物薄膜層は、少なくともアルミニウム
表面を一様に覆うまで形成することが望ましい。また厚
さが必要以上になると、被覆処理に時間がかかることな
どから、形成されるｆｉ膜層の厚さは、好ましくは０．
０２ないし５μｍ、より好ましくは０．１ないし２μｍ
である。
チタン、バナジウム、ニオブ、タンタル、ジルコニウム
、タングステンのこれら金属の炭窒化物は、一般にはサ
ーメットと称される起硬合金として知られており、これ
らの製造方法は、金属炭化物粉末や窒化物粉末を１００
０°Ｃを越える高温度で焼結して形成されている。しか
し、この発明で用いる基材は、アルミニウムであるため
、少な（とも表面に金属炭化物もしくは窒化物の粉末を
塗布して、焼結する方法を用いることはできない。また
薄膜化という課題に対しても焼結法は、目的達成には適
してはいない。
このような薄膜形成には、厚さや状態の制御が容易な物
理的手段によるドライプロセスによるのが好適である。
このような手段として、この発明では、陰極アーク蒸着
法を用いている。
陰極アーク蒸着法は、ターゲット側を陰極とした陰極ア
ーク放電現象を利用して、ターゲット材料を局所的に熔
融蒸発させ、被処理材料表面に蒸着を行うもので、陰極
アーク放電の特性として、陰極側（ターゲット）に非常
に小さな陰極輝点を生じ、大きなアーク電流がこの小さ
い点に流れ込むことから、陰極点の近傍は極めて高温に
熱せられて、チタン等のこの発明で用いる高融点金属を
瞬時に溶融蒸発させる。
そして溶融蒸発した、ターゲツト材は同時に金属イオン
となり、真空中に放出される。この際バイアス電圧を被
処理材料に印加することにより、この金属イオンは、加
速された反応ガス粒子と共に被処理材料の表面に密着し
、緻密な蒸着膜を生成する。
通常の陰極アーク蒸着法によれば、蒸着処理を行うチャ
ンバ内は、アルゴンガス等の不活性ガスが僅かに存在す
る雰囲気中で蒸着を行うが、この発明においては、金属
の炭窒化物からなる蒸着膜を形成する必要があることか
ら、チャンバ内に微量の炭素化合物ガスと窒素ガスを所
定量存在させて蒸着処理を行う。
チャンバ内に炭化のため存在させるガスは、炭化水素で
あるメタン、エチレンなどが好適である。
またガスの量は、炭化反応が充分行われ、しかも遊離し
た金属イオンが被処理材表面に蒸着形成されるのを妨げ
ない範囲で選択されるべきである。
また窒化のために、窒素ガスをチャンバ内に併せて存在
させる必要がある。これらガスの好ましい濃度範囲は炭
化水素化合物ガスと窒素ガス双方を含む全圧でＩ Ｘｌ
０−’〜Ｉ Ｘｌ０−’Ｔｏｒｒである。This invention utilizes titanium, vanadium, niobium, tantalum,
The electrolytic capacitor of the present invention focuses on the fact that a composite of carbide and nitride of a metal selected from zirconium and tungsten (hereinafter referred to as carbonitride) forms a thin film that is suitable for the purpose of the present invention. The electrode is characterized by forming a thin film layer made of carbonitride of any of the following metals: titanium, vanadium, niobium, tantalum, zirconium, and tungsten on the surface of high-purity aluminum. Another feature of the present invention is that cathodic arc evaporation is used as a means for forming a thin film of carbonitrides of these metals on the aluminum surface. According to the present invention, high-purity foil-like or plate-like aluminum used for the electrodes of ordinary electrolytic capacitors can be used as the material to be treated. This aluminum surface is cleaned in advance by degreasing or the like. Further, the aluminum surface may be subjected to an etching treatment or may be used as a blank. It is desirable that the carbonitride thin film layer be formed to at least uniformly cover the aluminum surface. Moreover, if the thickness becomes more than necessary, the coating process will take time, so the thickness of the FI film layer to be formed is preferably 0.0000.
02 to 5 μm, more preferably 0.1 to 2 μm
It is. Carbonitrides of these metals, such as titanium, vanadium, niobium, tantalum, zirconium, and tungsten, are generally known as hardening alloys called cermets, and the manufacturing method for these metal carbide powders and nitride powders is 100
It is formed by sintering at a high temperature exceeding 0°C. However, since the base material used in this invention is aluminum, it is not possible to use a method of coating metal carbide or nitride powder on the surface and sintering it. However, the sintering method is not suitable for achieving this purpose.For the formation of such a thin film, it is preferable to use a dry process using physical means that allows easy control of the thickness and condition.As such a method, This invention uses a cathodic arc evaporation method. The cathodic arc evaporation method uses a cathodic arc discharge phenomenon with the target side as a cathode to locally melt and evaporate the target material and deposit it on the surface of the material to be processed. As a characteristic of cathodic arc discharge, a very small cathode bright spot is created on the cathode side (target), and a large arc current flows into this small spot, so the area near the cathode spot is heated to an extremely high temperature. , titanium, and other high-melting point metals used in this invention are instantaneously melted and evaporated.Then, the melted and evaporated target material simultaneously becomes metal ions and is released into a vacuum.At this time, a bias voltage is applied to the material to be processed. As a result, these metal ions adhere to the surface of the material to be processed together with the accelerated reaction gas particles, producing a dense vapor deposited film.According to the normal cathodic arc vapor deposition method, the chamber in which the vapor deposition process is performed is filled with argon. Vapor deposition is performed in an atmosphere in which a small amount of inert gas such as gas exists, but in this invention, since it is necessary to form a vapor-deposited film made of metal carbonitride, a small amount of carbon compound gas is present in the chamber. The vapor deposition process is carried out in the presence of a predetermined amount of nitrogen gas.The gas to be present in the chamber for carbonization is preferably a hydrocarbon such as methane or ethylene.The amount of gas is determined so that the carbonization reaction is sufficiently carried out. Moreover, it should be selected within a range that does not prevent free metal ions from being deposited on the surface of the material to be treated.Also, nitrogen gas must also be present in the chamber for nitriding. The preferred concentration range of the gas is IXl at a total pressure including both hydrocarbon compound gas and nitrogen gas.
0-' to IXl0-'Torr.
この発明で選択した金属の炭窒化物は、いずれも硬質な
化合物でアルミニウムとの反応性も良好なことから、ア
ルミニウム表面に緻密な薄膜が形成される。そしてこの
金属の炭窒化物薄膜は、従来の同種の金属のみの蒸着に
比べて高い静電容量が得られることが判明した。
また金属炭窒化物の薄膜の形成に、陰極アーク蒸着法を
用いることにより、溶融金属と炭化水素ガスとの炭化反
応がアーク状態で行われ、反応後に被蒸着材であるアル
ミニウム表面に薄膜が形成されるので、低融点であるア
ルミニウム表面に炭窒化物薄膜を形成することができる
。
従来から、炭化物の気相反応によるものとして、ＣＶＤ
法によるものが知られているが、これは塩化チタンなど
のハロゲン化化合物を気化して反応を行わせるために、
アルミニウム表面にハロゲンが残留し、電極腐食の原因
となるが、陰極アーク蒸着によれば、金属自体をアーク
により蒸発させるので、ハロゲンガスを用いないため腐
食発生のおそれもない。The metal carbonitrides selected in this invention are all hard compounds and have good reactivity with aluminum, so that a dense thin film is formed on the aluminum surface. It was also found that this metal carbonitride thin film can provide higher capacitance than conventional vapor deposition of only the same type of metal. In addition, by using the cathodic arc evaporation method to form a thin film of metal carbonitride, the carbonization reaction between the molten metal and hydrocarbon gas takes place in an arc state, and after the reaction, a thin film is formed on the surface of the aluminum material to be deposited. Therefore, a carbonitride thin film can be formed on the surface of aluminum, which has a low melting point. Conventionally, CVD has been used as a method based on a gas phase reaction of carbides.
It is known that this method uses halogenated compounds such as titanium chloride to carry out the reaction.
Halogen remains on the aluminum surface and causes electrode corrosion, but with cathodic arc evaporation, the metal itself is evaporated by the arc and no halogen gas is used, so there is no risk of corrosion.
以下実施例に基づいて、この発明を更に詳細に説明する
。
まず、電極となる高純度アルミニウム被処理材を準備し
た。これは、交流による電気化学的なエツチング処理が
施された高純度のアルミニウム箔（純度９９．９５％）
を５０Ｘ １００朧に切断したものである。
この電極に陰極アーク蒸着装置を用いて表面に薄膜層を
形成した。
図面は、陰極アーク蒸着に使用する装置の概略を説明し
たものである。この発明は図面の装置により、タングス
テンからなる金属ターゲット（蒸発源）１０を陰極とし
てアーク放電を起こすと、アークは金属ターゲット１０
の表面にアークスポットを形成し、アークスポットに集
中するアーク電流のエネルギーにより、金属ターゲット
１０の表面は瞬時に溶融蒸発すると同時に金属イオン１
２となり、真空中に放出される。
この際、高純度のアルミニウムからなる被処理材１４に
対しバイアス電圧を印加することにより、この金属イオ
ン１２は、加速された反応ガス粒子１６と共に被処理材
１４の表面に密着し、緻密な膜を生成する。なお、図面
中で、１８および２０はアーク電源、２２はバイアス電
源、２４は回転テーブル、２６はガス入口、２８はガス
出口、３０は真空チャンバである。
陰極アーク蒸着装置の金属ターゲラ）１０として、チタ
ン、バナジウム、ニオブ、タンタル、ジルコニウム、タ
ングステンをそれぞれ用いた。そして、この発明例は以
下の蒸着条件によって被処理アルミニウム材表面に金属
炭窒化物薄膜層を形成した。
実施例の蒸着条件
基板（アルミニウム電極）温度 ２００℃チャンバー圧
力（メタンガスおよび窒素ガス双方を含む全圧）
２０ ×１０−３Ｔｏｒｒ
蒸着速度 ０．１ ｐｍ１分蒸着時間
２分
アーク放電電圧 １００■アーク放電電流
１５０Ａ次に、比較例としてチャンバ
ー内のガスを不活性ガス（アルゴンガス）のみとして、
同じ金属ターゲットを用いて、炭窒・化物でない金属自
体の薄膜を形成した。この比較例の蒸着条件を以下のと
おり示す。
比較例の蒸着条件
基板（アルミニウム電極）温度 ２００°Ｃチャンバー
圧力（アルゴンガスのみ）
２０Ｘ１０−’Ｔｏｒｒ
蒸着速度 ０．１ βｍ／分蒸着時間
２分
アーク放電電圧 １００■アーク放電電流
２０ＯＡこうして薄膜が形成された、ア
ルミニウム電極の静電容量を測定したところ第１表の結
果が得られた。
この結果から明らかなように、実施例の電極は、金属薄
膜が形成された比較例に比べていずれも高い静電容量値
を示し、静電容量の増大に寄与しいることがわかる。因
みに、エツチング処理のみが行われた、被処理材のアル
ミニウム自体の静電容量を測定したところ、その値は０
．４４ｍＦ／ｃ４に過ぎなかった。
次に形成された薄膜の安定性を調べるために、これら各
々の電極を電解コンデンサの電解液中に浸漬し、１１０
°Ｃで５００時間放置した後の静電容量を測定し、初期
の値に対する静電容量の減少の変化率を調べた。
使用した電解液の組成は、エチレングリコール７８重量
％、アジピン酸アンモニウム１０重量％、水１２重量％
の組成からなるもので、通常用いられる電解液に比べて
、水の含有量を多くしである。これは、水による電極箔
の水和劣化の発生が顕著になるようにしたためである。
この結果を第２表に示す。
第一」し−表
この結果のように、電解液中での安定性についいても、
この発明の金属炭窒化物薄膜は従来のものに比べて皮膜
の劣化がなく、安定した特性を維持することができる。
因みに、エツチング処理のみの電極についても同様の実
験を行ったところ、その静電容量変化率は、実に一５１
％にも達し、皮膜の劣化が激しいことがわかった。The present invention will be described in more detail below based on Examples. First, a high-purity aluminum material to be treated that would become an electrode was prepared. This is high-purity aluminum foil (99.95% purity) that has been electrochemically etched using alternating current.
It was cut into 50×100 pieces. A thin film layer was formed on the surface of this electrode using a cathodic arc evaporation device. The drawings schematically illustrate an apparatus used for cathodic arc deposition. This invention uses the device shown in the drawings to cause arc discharge using a metal target (evaporation source) 10 made of tungsten as a cathode.
An arc spot is formed on the surface of the metal target 10, and due to the energy of the arc current concentrated on the arc spot, the surface of the metal target 10 instantly melts and evaporates, and at the same time metal ions 1
2 and is released into vacuum. At this time, by applying a bias voltage to the material to be processed 14 made of high-purity aluminum, the metal ions 12, together with the accelerated reaction gas particles 16, adhere to the surface of the material to be processed 14, forming a dense film. generate. In the drawings, 18 and 20 are arc power sources, 22 is a bias power source, 24 is a rotary table, 26 is a gas inlet, 28 is a gas outlet, and 30 is a vacuum chamber. Titanium, vanadium, niobium, tantalum, zirconium, and tungsten were used as the metal target layer 10 of the cathodic arc evaporation apparatus. In this invention example, a metal carbonitride thin film layer was formed on the surface of the aluminum material to be treated under the following vapor deposition conditions. Vapor deposition conditions of the example Substrate (aluminum electrode) temperature 200°C Chamber pressure (total pressure including both methane gas and nitrogen gas) 20 × 10-3 Torr Vapor deposition rate 0.1 pm 1 minute Vapor deposition time
2 minutes Arc discharge voltage: 100■ Arc discharge current: 150ANext, as a comparative example, the gas in the chamber is only inert gas (argon gas).
Using the same metal target, a thin film of the metal itself, which is not a carbonitride or oxide, was formed. The vapor deposition conditions for this comparative example are shown below. Vapor deposition conditions for comparative example Substrate (aluminum electrode) temperature 200°C Chamber pressure (argon gas only) 20X10-'Torr Vapor deposition rate 0.1 βm/min Vapor deposition time
2 minutes Arc discharge voltage: 100 ■ Arc discharge current: 20OA When the capacitance of the aluminum electrode on which the thin film was thus formed was measured, the results shown in Table 1 were obtained. As is clear from the results, the electrodes of the examples all exhibited higher capacitance values than the comparative example in which a metal thin film was formed, and it can be seen that the electrodes contributed to an increase in capacitance. Incidentally, when we measured the capacitance of the aluminum itself, which was the material to be treated after only etching, the value was 0.
．． It was only 44mF/c4. Next, in order to examine the stability of the formed thin film, each of these electrodes was immersed in an electrolytic solution of an electrolytic capacitor.
The capacitance after being left at °C for 500 hours was measured, and the rate of change in capacitance reduction relative to the initial value was investigated. The composition of the electrolyte used was 78% by weight of ethylene glycol, 10% by weight of ammonium adipate, and 12% by weight of water.
It has a higher water content than commonly used electrolytes. This is to make the occurrence of hydration deterioration of the electrode foil due to water more noticeable. The results are shown in Table 2. As shown in the results, stability in the electrolyte is also
The metal carbonitride thin film of the present invention does not deteriorate as compared to conventional films and can maintain stable characteristics. Incidentally, when we conducted a similar experiment with an electrode that had only been etched, the rate of change in capacitance was actually 151%.
%, indicating severe deterioration of the film.
以上述べたようにこの発明によれば、電解コンデンサ用
の電極として、単位面積あたりの静電容量を高めること
ができるので、小型大容量の電解コンデンサが得られる
。
また電極表面が安定した金属の炭窒化物によって保護さ
れ、水和劣化等の電極表面の劣化が防止されるので、長
期にわたって安定した特性が維持できる。
またこの発明では、炭化水素ガスと窒素ガスとを含む雰
囲気中で陰極アーク蒸着法により、アルミニウム表面に
金属の炭窒化物からなる薄膜層を形成するので、基材が
低融点のアルミニウムであっても、薄膜層の形成が可能
となる。しかも薄膜形成処理にハロゲンガスを使わない
ので、電極の腐食の恐れもない。
また陰極アーク蒸着法は、短時間で処理が行え、製造効
率を高めることができる。As described above, according to the present invention, as an electrode for an electrolytic capacitor, the capacitance per unit area can be increased, so a small-sized, large-capacity electrolytic capacitor can be obtained. Furthermore, since the electrode surface is protected by stable metal carbonitride and deterioration of the electrode surface such as hydration deterioration is prevented, stable characteristics can be maintained over a long period of time. In addition, in this invention, a thin film layer made of metal carbonitride is formed on the aluminum surface by cathodic arc evaporation in an atmosphere containing hydrocarbon gas and nitrogen gas, so that the base material is aluminum with a low melting point. Also, it becomes possible to form a thin film layer. Moreover, since halogen gas is not used in the thin film formation process, there is no risk of corrosion of the electrodes. Further, the cathodic arc evaporation method allows processing to be performed in a short time and can improve manufacturing efficiency.
図面はこの発明で用いる陰極アーク蒸着装置の概略を表
した説明図である。
１０・・・金属ターゲット （蒸発源）１２・・・金属
イオン １４・・・被処理材１６・・・反応ガス粒
子
２０・・・アーク電源
２４・・・回転テーブル
２８・・・ガス出口
１８・・・アーク電源
２２・・・バイアス電源
２６・・・ガス入口
３０：・・真空チャンバThe drawing is an explanatory diagram schematically showing a cathodic arc evaporation apparatus used in the present invention. 10... Metal target (evaporation source) 12... Metal ion 14... Material to be treated 16... Reactive gas particles 20... Arc power source 24... Rotary table 28... Gas outlet 18. ...Arc power supply 22...Bias power supply 26...Gas inlet 30: ...Vacuum chamber
Claims (2)
、ニオブ、タンタル、ジルコニウム、タングステンから
選ばれたいずれか金属の炭窒化物からなる薄膜を形成し
たことを特徴とする電解コンデンサ用アルミニウム電極
。(1) An aluminum electrode for an electrolytic capacitor, characterized in that a thin film made of carbonitride of any metal selected from titanium, vanadium, niobium, tantalum, zirconium, and tungsten is formed on the surface of high-purity aluminum.
チタン、バナジウム、ニオブ、タンタル、ジルコニウム
、タングステンから選ばれたいずれか金属をターゲット
として、陰極アーク蒸着法によって高純度アルミニウム
表面に前記金属の炭窒化物からなる蒸着層を形成するこ
とを特徴とする電解コンデンサ用アルミニウム電極の製
造方法。(2) In an atmosphere containing hydrocarbon gas and nitrogen gas,
It is characterized by forming a vapor deposition layer consisting of carbonitride of the metal on the surface of high-purity aluminum by cathodic arc evaporation using any metal selected from titanium, vanadium, niobium, tantalum, zirconium, and tungsten as a target. Method for manufacturing aluminum electrodes for electrolytic capacitors.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18483190A JP2618281B2 (en) | 1990-07-12 | 1990-07-12 | Aluminum electrode for electrolytic capacitor and method of manufacturing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18483190A JP2618281B2 (en) | 1990-07-12 | 1990-07-12 | Aluminum electrode for electrolytic capacitor and method of manufacturing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0471214A true JPH0471214A (en) | 1992-03-05 |
| JP2618281B2 JP2618281B2 (en) | 1997-06-11 |
Family
ID=16160068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18483190A Expired - Lifetime JP2618281B2 (en) | 1990-07-12 | 1990-07-12 | Aluminum electrode for electrolytic capacitor and method of manufacturing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2618281B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004047131A1 (en) * | 2002-11-19 | 2004-06-03 | Sanyo Electric Co., Ltd. | Solid electrolytic capacitor |
| JP2005109078A (en) * | 2003-09-30 | 2005-04-21 | Nippon Chemicon Corp | Method of manufacturing solid electrolytic capacitor |
| US7167356B2 (en) * | 2003-02-12 | 2007-01-23 | Sanyo Electric Co., Ltd. | Solid electrolytic capacitor |
| JP4965455B2 (en) * | 2005-11-10 | 2012-07-04 | 東洋アルミニウム株式会社 | Electrode structure, capacitor, and method of manufacturing electrode structure |
| JP2014051742A (en) * | 2007-12-03 | 2014-03-20 | Kobe Steel Ltd | Method of forming hard film having excellent slidability |
| US9418796B2 (en) | 2011-02-21 | 2016-08-16 | Japan Capacitor Industrial Co., Ltd. | Electrode foil, current collector, electrode, and electric energy storage element using same |
-
1990
- 1990-07-12 JP JP18483190A patent/JP2618281B2/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004047131A1 (en) * | 2002-11-19 | 2004-06-03 | Sanyo Electric Co., Ltd. | Solid electrolytic capacitor |
| US7158367B2 (en) | 2002-11-19 | 2007-01-02 | Sanyo Electric Co., Ltd. | Solid electrolytic capacitor |
| US7428139B2 (en) | 2002-11-19 | 2008-09-23 | Sanyo Electric Co., Ltd. | Solid electrolytic capacitor |
| US7167356B2 (en) * | 2003-02-12 | 2007-01-23 | Sanyo Electric Co., Ltd. | Solid electrolytic capacitor |
| JP2005109078A (en) * | 2003-09-30 | 2005-04-21 | Nippon Chemicon Corp | Method of manufacturing solid electrolytic capacitor |
| JP4529404B2 (en) * | 2003-09-30 | 2010-08-25 | 日本ケミコン株式会社 | Manufacturing method of solid electrolytic capacitor |
| JP4965455B2 (en) * | 2005-11-10 | 2012-07-04 | 東洋アルミニウム株式会社 | Electrode structure, capacitor, and method of manufacturing electrode structure |
| JP2014051742A (en) * | 2007-12-03 | 2014-03-20 | Kobe Steel Ltd | Method of forming hard film having excellent slidability |
| US9418796B2 (en) | 2011-02-21 | 2016-08-16 | Japan Capacitor Industrial Co., Ltd. | Electrode foil, current collector, electrode, and electric energy storage element using same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2618281B2 (en) | 1997-06-11 |
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