JPH08134693A - Production of high dielectric constant composite aluminum oxide coating film - Google Patents
Production of high dielectric constant composite aluminum oxide coating filmInfo
- Publication number
- JPH08134693A JPH08134693A JP27784294A JP27784294A JPH08134693A JP H08134693 A JPH08134693 A JP H08134693A JP 27784294 A JP27784294 A JP 27784294A JP 27784294 A JP27784294 A JP 27784294A JP H08134693 A JPH08134693 A JP H08134693A
- Authority
- JP
- Japan
- Prior art keywords
- dielectric constant
- aluminum oxide
- salicylate
- composite aluminum
- coating film
- 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
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- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は高誘電率複合酸化アルミ
ニウム皮膜の製造方法に関する。高誘電率複合酸化アル
ミニウム皮膜は、高い静電容量の要求される電解コンデ
ンサやプリント基板上の印刷コンデンサ、マイクロ波用
の誘電体共振器、ＩＣ、液晶ＴＦＴの誘電体、絶縁体と
して利用される。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high dielectric constant composite aluminum oxide film. The high-dielectric-constant composite aluminum oxide film is used as an electrolytic capacitor that requires high capacitance, a printed capacitor on a printed board, a dielectric resonator for microwaves, an IC, a dielectric of a liquid crystal TFT, and an insulator. .
【０００２】[0002]
【従来の技術】アルミニウムの陽極酸化は古くから良く
知られた原理であり、工業的に多方面に利用されてい
る。陽極酸化は通常、水系の電解液中で実施され、使用
する電解液の種類によってポーラス型とバリアー型とい
われる大別して２種類の酸化皮膜が形成されることが知
られている。バリアー型皮膜は撤密で電気絶縁性が高い
ので、電解コンデンサの誘電膜や半導体上のアルミニウ
ム配線の絶縁膜等に応用されている。2. Description of the Related Art The anodic oxidation of aluminum has been a well-known principle since ancient times and has been industrially used in various fields. It is known that anodization is usually carried out in an aqueous electrolytic solution, and two types of oxide films, which are roughly classified into a porous type and a barrier type, are formed depending on the type of the electrolytic solution used. Since the barrier type film is dense and has high electric insulation, it is applied to a dielectric film of an electrolytic capacitor, an insulating film of aluminum wiring on a semiconductor, and the like.
【０００３】アルミニウム電解コンデンサは、電気化学
的あるいは化学的に表面を粗面化したアルミニウム箔を
ほう酸系、リン酸系あるいはアジピン酸系の水溶液で陽
極酸化処理し、酸化アルミニウム皮膜層を形成した化成
箔を陽極側電極に用いている（金属表面技術 ６７１頁
（１９７６）日刊工業新聞社、実験表面技術 ３５
（６）、２６１（１９８８））。In an aluminum electrolytic capacitor, an aluminum foil whose surface is electrochemically or chemically roughened is anodized with an aqueous solution of boric acid, phosphoric acid or adipic acid to form an aluminum oxide film layer. Foil is used for the anode electrode (Metal surface technology, page 671 (1976), Nikkan Kogyo Shimbun, Experimental surface technology 35
(6), 261 (1988)).
【０００４】一般に、平行板コンデンサの静電容量Ｃ
は、 Ｃ＝ε0・εr・Ａ／ｄ （ただし、ε0；真空の誘電率、εr；比誘電率、Ａ；電
極面積、ｄ；誘電体の厚み）によって定義される。高い
静電容量のコンデンサを得るためには、（１）誘電体の
比誘電率を向上させるか、（２）表面積を拡大するかあ
るいは薄くするかのいずれかの方法になる。酸化アルミ
ニウムの比誘電率は７〜１０であり、また、酸化皮膜を
薄くすると耐電圧が低下するので、電極表面積を電解エ
ッチングで拡大することで高静電容量化が達成されてき
た。Generally, the capacitance C of a parallel plate capacitor
Is defined by C = ε 0 · ε r · A / d (where, ε 0 is a vacuum permittivity, ε r is a relative permittivity, A is an electrode area, and d is a dielectric thickness). In order to obtain a capacitor having a high capacitance, either (1) improving the relative permittivity of the dielectric material, or (2) expanding or thinning the surface area is used. Aluminum oxide has a relative permittivity of 7 to 10, and since the withstand voltage decreases when the oxide film is thinned, high electrostatic capacity has been achieved by increasing the electrode surface area by electrolytic etching.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、近年の
電子機器の軽薄短小化の流れのなかで、電解コンデンサ
もチップ化、小型化の要求が強く、そのためには電極箔
のさらなる高静電容量化が望まれている。また、プリン
ト基板回路あるいは半導体回路上の誘電膜や絶縁膜にも
同様な課題がある。本発明は、このような要請に応え得
る高誘電率複合酸化アルミニウム皮膜の製造方法を提供
しようというものである。However, in the recent trend toward lighter, thinner, shorter, and smaller electronic devices, there is a strong demand for electrolytic capacitors to be made into chips and smaller in size. For that purpose, the electrostatic capacitance of electrode foils is further increased. Is desired. Further, a dielectric film or an insulating film on a printed circuit board or a semiconductor circuit has a similar problem. The present invention intends to provide a method for producing a high dielectric constant composite aluminum oxide film which can meet such demands.
【０００６】[0006]
【課題を解決するための手段】即ち、本発明は、炭素を
含有し、比誘電率２０以上の高誘電率複合酸化アルミニ
ウム皮膜の製造方法を提供するものである。That is, the present invention provides a method for producing a high dielectric constant composite aluminum oxide film containing carbon and having a relative dielectric constant of 20 or more.
【０００７】[0007]
【作用】水が存在しない系あるいは微量な系での陽極酸
化においては、サリチル酸塩中のサリチル酸の酸素が酸
素源となりうる。そのため陽極酸化により、サリチル酸
塩中のサリチル酸の酸素原子とともにサリチル酸を形成
する炭素が含有され、従来の酸化アルムニウム皮膜に比
べ比誘電率が２倍以上高い、即ち比誘電率が２０以上に
大幅に増加する。In the anodic oxidation in a system without water or in a trace amount, oxygen of salicylic acid in salicylate can serve as an oxygen source. Therefore, by anodic oxidation, carbon that forms salicylic acid is included with the oxygen atom of salicylic acid in salicylate, and the relative permittivity is twice or more higher than that of the conventional aluminum oxide film, that is, the relative permittivity is greatly increased to 20 or more. To do.
【０００８】（発明の概要）本発明の高誘電率複合酸化
アルミニウム皮膜は、サリチル酸塩を含んでなる実質的
に無水の非水系電解液中でアルミニウムを電解陽極酸化
することにより得られる。本発明の方法に用いる非水系
電解液としては、サリチル酸塩の非水系溶媒溶液が用い
られる。上記サリチル酸塩としては、サリチル酸の１、
２、３または４級のアンモニウム塩、アルカリ金属塩、
四級ホスホニウム塩、スルホニウム塩等を例示すること
ができる。(Summary of the Invention) The high dielectric constant composite aluminum oxide film of the present invention is obtained by electrolytic anodization of aluminum in a substantially anhydrous non-aqueous electrolytic solution containing a salicylate. As the non-aqueous electrolytic solution used in the method of the present invention, a non-aqueous solvent solution of salicylate is used. The salicylates include salicylic acid 1,
Secondary, tertiary or quaternary ammonium salt, alkali metal salt,
Examples thereof include quaternary phosphonium salts and sulfonium salts.
【０００９】非水系溶媒としては、エチレングリコー
ル、メチルセロソルブ等のアルコール系溶媒；γ−ブチ
ロラクトン、γ−バレロラクトン、δ−バレロラクトン
等のラクトン系溶媒；エチレンカーボネート、プロピレ
ンカーボネート、ブチレンカーボネート等のカーボネー
ト系溶媒；Ｎ−メチルホルムアミド、Ｎ−エチルホルム
アミド、Ｎ，Ｎ−ジメチルホルムアミド、Ｎ，Ｎ−ジエ
チルホルムアミド、Ｎ−メチルアセトアミド、Ｎ，Ｎ−
ジメチルアセトアミド、Ｎ−メチルピロリジノン等のア
ミド系溶媒；３−メトキシプロピオニトリル、グルタロ
ニトリル等のニトリル系溶媒；トリメチルホスフェー
ト、トリエチルホスフェート等のリン酸エステル系溶
媒；及び、これらの２種以上の溶媒の混合物等の極性溶
媒、並びに、ヘキサン、トルエン、シリコンオイル等の
非極性溶媒を例示することが出来るが、サリチル酸塩を
溶解し易い極性溶媒が好ましい。Examples of the non-aqueous solvent include alcohol solvents such as ethylene glycol and methyl cellosolve; lactone solvents such as γ-butyrolactone, γ-valerolactone and δ-valerolactone; carbonates such as ethylene carbonate, propylene carbonate and butylene carbonate. System solvent; N-methylformamide, N-ethylformamide, N, N-dimethylformamide, N, N-diethylformamide, N-methylacetamide, N, N-
Amide solvents such as dimethylacetamide and N-methylpyrrolidinone; nitrile solvents such as 3-methoxypropionitrile and glutaronitrile; phosphate ester solvents such as trimethyl phosphate and triethyl phosphate; and two or more of these. Examples thereof include polar solvents such as a mixture of solvents, and nonpolar solvents such as hexane, toluene, silicone oil, etc., but polar solvents that easily dissolve salicylate are preferable.
【００１０】使用するサリチル酸塩の濃度は、得るべき
電解液の電導度、火花電圧により異なるが、一般的に飽
和濃度以下、好ましくは０．１〜２ｍｏｌ／ｌである。
また、高誘電率複合酸化アルミニウム皮膜を得るために
は、電解液は実質的に無水である必要があり、具体的に
は、電解液の水分量は０．１重量％以下、好ましくは
０．０５重量％以下にする必要がある。水分量を減らす
ことにより高誘電率複合酸化アルミニウム皮膜の比誘電
率をさらに高くすることができる。水分量が多すぎると
水分を酸素源とする通常の酸化皮膜を形成するため、得
られる酸化皮膜の比誘電率は向上しない。The concentration of salicylate to be used varies depending on the conductivity of the electrolyte to be obtained and the spark voltage, but it is generally below the saturation concentration, preferably 0.1 to 2 mol / l.
Further, in order to obtain a high-dielectric-constant composite aluminum oxide film, the electrolytic solution needs to be substantially anhydrous, and specifically, the electrolytic solution has a water content of 0.1% by weight or less, preferably 0. It is necessary to set it to 05% by weight or less. By reducing the water content, the relative dielectric constant of the high dielectric constant composite aluminum oxide film can be further increased. If the water content is too large, a normal oxide film using water as an oxygen source is formed, and the relative permittivity of the resulting oxide film is not improved.
【００１１】陽極酸化は一般的に、上記の電解浴中で、
室温〜１５０℃の温度範囲で、電流密度０．５〜５０mA
／cm2 の範囲で行われる。電解陽極酸化時間は電極面積
により定められる。上記の方法により、炭素を１〜５０
重量％含有し、比誘電率２０以上、好ましくは３０〜３
００の高誘電率複合酸化アルミニウム皮膜を得ることが
できる。Anodization is generally carried out in the above electrolytic bath,
Current density 0.5 to 50mA in the temperature range of room temperature to 150 ℃
It is performed in the range of / cm 2 . The electrolytic anodic oxidation time is determined by the electrode area. By the above method, 1 to 50 carbon
%, Relative permittivity of 20 or more, preferably 30 to 3
A high dielectric constant composite aluminum oxide film of No. 00 can be obtained.
【００１２】本発明の高誘電率複合酸化アルミニウム皮
膜の膜厚は化成電圧により任意に定められ、１０〜１０
００ｎｍのものが得られる。The film thickness of the high-dielectric-constant composite aluminum oxide film of the present invention is arbitrarily determined by the formation voltage and is 10 to 10
A value of 00 nm is obtained.
【００１３】[0013]
【実施例】以下に実施例および比較例を挙げて本発明を
さらに詳細に説明する。 （実施例１）１モル濃度のサリチル酸テトラエチルアン
モニウムを含むγ−ブチロラクトン溶液を調製し、減圧
加熱して脱水した。このときの電解液の水分は２０ｐｐ
ｍであった。この電解液を使用して、アルミニウム箔を
５mA／cm2 の定電流で７５Ｖまで陽極酸化して化成箔を
得た。得た化成箔のＴＥＭ（走査透過型電子顕微鏡）に
よる断面の観察の結果、皮膜はほぼ平滑で、表面積は陽
極酸化前とほとんど変化しておらず、膜厚は８０ｎｍで
あった。得られた化成箔を、１０重量％のアジピン酸ア
ンモニウム水溶液に浸し、ＬＣＲメータで１２０Ｈｚに
おける静電容量を測定した。１２０Ｈｚにおける静電容
量は１．９μＦ／ｃｍ2 であった。静電容量と膜厚から
求めた比誘電率を表１に示す。EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below. Example 1 A γ-butyrolactone solution containing 1 molar concentration of tetraethylammonium salicylate was prepared and dehydrated by heating under reduced pressure. The water content of the electrolyte at this time is 20 pp
It was m. Using this electrolytic solution, an aluminum foil was anodized to 75 V at a constant current of 5 mA / cm 2 to obtain a chemical conversion foil. As a result of observing a cross section of the obtained chemical conversion foil with a TEM (scanning transmission electron microscope), the film was almost smooth, the surface area was almost unchanged from that before the anodization, and the film thickness was 80 nm. The obtained formed foil was dipped in a 10% by weight ammonium adipate aqueous solution, and the electrostatic capacity at 120 Hz was measured with an LCR meter. The capacitance at 120 Hz was 1.9 μF / cm 2 . Table 1 shows the relative permittivity obtained from the capacitance and the film thickness.
【００１４】（実施例２）１モル濃度のサリチル酸のテ
トラエチルアンモニウム塩を含むプロピレンカーボネー
ト溶液を調製し、減圧加熱して脱水した。このときの電
解液の水分は３０ｐｐｍであった。この電解液を使用し
て、アルミニウムを５mA／cm2 の定電流で５０Ｖまで陽
極酸化して化成箔を得た。得た化成箔を、１０重量％の
アジピン酸アンモニウム水溶液に浸し、ＬＣＲメータで
静電容量を測定した。実施例１と同様にして求めた比誘
電率を表１に示す。Example 2 A propylene carbonate solution containing 1 molar concentration of a tetraethylammonium salt of salicylic acid was prepared and dehydrated by heating under reduced pressure. The electrolytic solution had a water content of 30 ppm. Using this electrolyte, aluminum was anodized at a constant current of 5 mA / cm 2 to 50 V to obtain a chemical conversion foil. The obtained formed foil was dipped in a 10% by weight ammonium adipate aqueous solution, and the capacitance was measured with an LCR meter. Table 1 shows the relative permittivity obtained in the same manner as in Example 1.
【００１５】（比較例１）化成用電解液としてアルミニ
ウム電解コンデンサ用化成箔の製造に使用されている１
０重量％のアジピン酸アンモニウム水溶液を用い、化成
電圧を７５Ｖとした他は実施例１と同様にしてアルミニ
ウム箔を陽極酸化した。得た化成箔を、１０重量％のア
ジピン酸アンモニウム水溶液に浸し、ＬＣＲメータで静
電容量を測定した。１２０Ｈｚにおける静電容量は０．
０８８μＦ／ｃｍ2 であった。また、ＴＥＭによる断面
の観察から皮膜の膜厚は８０ｎｍであり、静電容量と膜
厚から算出した比誘電率は８．０であった。(Comparative Example 1) Used as a chemical conversion electrolytic solution in the production of a chemical conversion foil for aluminum electrolytic capacitors 1
The aluminum foil was anodized in the same manner as in Example 1 except that a 0% by weight ammonium adipate aqueous solution was used and the formation voltage was set to 75V. The obtained formed foil was dipped in a 10% by weight ammonium adipate aqueous solution, and the capacitance was measured with an LCR meter. The capacitance at 120 Hz is 0.
It was 088 μF / cm 2 . Further, the film thickness of the film was 80 nm from the observation of the cross section by TEM, and the relative dielectric constant calculated from the capacitance and the film thickness was 8.0.
【００１６】（比較例２）化成用電解液として、水分９
００ｐｐｍで１モル濃度のフタル酸水素テトラメチルア
ンモニウムを含むγ−ブチロラクトン溶液を用い、化成
電圧を７５Ｖとした他は実施例１と同様にしてアルミニ
ウム箔を陽極酸化した。得た化成箔を、１０重量％のア
ジピン酸アンモニウム水溶液に浸し、ＬＣＲメータで静
電容量を測定した。実施例１と同様にして求めた比誘電
率を表１に示す。Comparative Example 2 Moisture 9 was used as the electrolytic solution for chemical conversion.
An aluminum foil was anodized in the same manner as in Example 1 except that a γ-butyrolactone solution containing 1 ppm of tetramethylammonium hydrogen phthalate at 00 ppm was used and the formation voltage was set to 75V. The obtained formed foil was dipped in a 10% by weight ammonium adipate aqueous solution, and the capacitance was measured with an LCR meter. Table 1 shows the relative permittivity obtained in the same manner as in Example 1.
【００１７】[0017]
【表１】 [Table 1]
【００１８】[0018]
【発明の効果】本発明の方法によれば、得られる高誘電
率複合酸化アルミニウム皮膜は、従来の水系化成用電解
液で形成した絶縁皮膜よりも２倍以上高い、２０以上の
比誘電率の皮膜を形成でき、本発明により得られた高誘
電率複合酸化アルミニウム皮膜を用いることにより、同
一サイズで高い静電容量あるいは同一静電容量で小さい
サイズの電解コンデンサを実現することが可能になる。According to the method of the present invention, the high dielectric constant composite aluminum oxide film obtained has a relative dielectric constant of 20 or more, which is twice or more higher than that of the insulating film formed by the conventional aqueous chemical conversion electrolyte solution. A film can be formed, and by using the high-dielectric-constant composite aluminum oxide film obtained by the present invention, it is possible to realize an electrolytic capacitor having the same size and high capacitance or the same capacitance and small size.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 関川 佐千江 茨城県稲敷郡阿見町中央８丁目３番１号 三菱化学株式会社筑波研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sachie Sachie 8-3-1 Chuo, Ami-cho, Inashiki-gun, Ibaraki Mitsubishi Chemical Corporation Tsukuba Research Center
Claims (1)
の非水系電解液中でアルミニウムを電解陽極酸化するこ
とを特徴とする、炭素を１〜５０重量％含有し、比誘電
率２０以上の高誘電率複合酸化アルミニウム皮膜の製造
方法。1. Aluminum is electrolytically anodized in a substantially anhydrous non-aqueous electrolyte containing salicylate, containing 1 to 50% by weight of carbon and having a relative dielectric constant of 20 or more. Method for producing high dielectric constant composite aluminum oxide film.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27784294A JPH08134693A (en) | 1994-11-11 | 1994-11-11 | Production of high dielectric constant composite aluminum oxide coating film |
| US08/551,999 US5733661A (en) | 1994-11-11 | 1995-11-02 | High-permittivity composite oxide film and uses thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27784294A JPH08134693A (en) | 1994-11-11 | 1994-11-11 | Production of high dielectric constant composite aluminum oxide coating film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08134693A true JPH08134693A (en) | 1996-05-28 |
Family
ID=17589030
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27784294A Pending JPH08134693A (en) | 1994-11-11 | 1994-11-11 | Production of high dielectric constant composite aluminum oxide coating film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08134693A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100354456C (en) * | 2004-04-20 | 2007-12-12 | 中国科学院理化技术研究所 | Preparation method of alumina template with controllable aperture |
| JP2015046633A (en) * | 2005-09-13 | 2015-03-12 | ハー．ツェー．スタルク ゲゼルシャフト ミット ベシュレンクテル ハフツングＨ．Ｃ． Ｓｔａｒｃｋ ＧｍｂＨ | Method for manufacturing electrolytic capacitor with high nominal voltage |
| CN113512744A (en) * | 2021-06-30 | 2021-10-19 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Protection method of high-corrosion-resistance airborne aluminum-based LRM module |
-
1994
- 1994-11-11 JP JP27784294A patent/JPH08134693A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100354456C (en) * | 2004-04-20 | 2007-12-12 | 中国科学院理化技术研究所 | Preparation method of alumina template with controllable aperture |
| JP2015046633A (en) * | 2005-09-13 | 2015-03-12 | ハー．ツェー．スタルク ゲゼルシャフト ミット ベシュレンクテル ハフツングＨ．Ｃ． Ｓｔａｒｃｋ ＧｍｂＨ | Method for manufacturing electrolytic capacitor with high nominal voltage |
| CN113512744A (en) * | 2021-06-30 | 2021-10-19 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Protection method of high-corrosion-resistance airborne aluminum-based LRM module |
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