JPH0917685A - Capacitor and its manufacture - Google Patents

Capacitor and its manufacture

Info

Publication number
JPH0917685A
JPH0917685A JP16105195A JP16105195A JPH0917685A JP H0917685 A JPH0917685 A JP H0917685A JP 16105195 A JP16105195 A JP 16105195A JP 16105195 A JP16105195 A JP 16105195A JP H0917685 A JPH0917685 A JP H0917685A
Authority
JP
Japan
Prior art keywords
sintered body
capacitor
film
dielectric film
electrode
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
JP16105195A
Other languages
Japanese (ja)
Inventor
Yasuyuki Naito
康行 内藤
Mikio Hayashi
幹生 林
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.)
Murata Manufacturing Co Ltd
Original Assignee
Murata Manufacturing 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 Murata Manufacturing Co Ltd filed Critical Murata Manufacturing Co Ltd
Priority to JP16105195A priority Critical patent/JPH0917685A/en
Priority to US08/673,176 priority patent/US5790368A/en
Publication of JPH0917685A publication Critical patent/JPH0917685A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE: To provide a capacitor, which excels in productivity, is small in size and has a large capacity, and its manufacture, without necessitating a complicated manufacturing process. CONSTITUTION: A capacitor is provided with a porous sintered body 2 composed of metal whose major component is titanium, a dielectric film 3, which is formed on the surface of the sintered body and contains composite oxide expressed by a general formula, ATiO3 , where A is Ba or Sr, as the major component, conductor or semiconductor formed on the surface of the dielectric film and a counter electrode which allows continuity with the conductor or semiconductor and faces the sintered body. The porosity of the sintered body is 20% or more. The composite oxide film expressed by the formula on the surface of the sintered body is formed as the dielectric film 3 by impregnating the sintered body in the aqueous solution that contains strontium or barium, performing hydrothermal treatment at a prescribed temperature. Then, the capacitor is formed by forming the conductor or semiconductor electrode 4 on the surface of the oxide film and forming the counter electrode that allows continuity with the electrode and faces the sintered body.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】この発明は、コンデンサに関し、
詳しくは、小型で大きな静電容量を得ることが可能なコ
ンデンサとその製造方法に関する。
BACKGROUND OF THE INVENTION The present invention relates to a capacitor,
More specifically, the present invention relates to a compact capacitor capable of obtaining a large capacitance and a method for manufacturing the same.

【0002】[0002]

【従来の技術】従来の小型大容量コンデンサとしては、
例えば、タンタル電解コンデンサやアルミニウム電解コ
ンデンサなどの電解コンデンサが知られている。
2. Description of the Related Art As a conventional small-sized large-capacity capacitor,
For example, electrolytic capacitors such as tantalum electrolytic capacitors and aluminum electrolytic capacitors are known.

【0003】タンタル電解コンデンサは、金属タンタル
の陽極酸化皮膜を誘電体として利用したコンデンサであ
り、長寿命であること、温度特性が良好であること、小
型化できること、周波数特性が比較的良好であることな
どの特徴を有している。
A tantalum electrolytic capacitor is a capacitor using a metal tantalum anodic oxide film as a dielectric and has a long life, good temperature characteristics, miniaturization, and relatively good frequency characteristics. It has features such as that.

【0004】また、アルミニウム電解コンデンサは、上
記のタンタル電解コンデンサよりも大きな静電容量を得
ることができるという特徴を有しており、電源回路など
に広く用いられている。
Further, the aluminum electrolytic capacitor is characterized in that it can obtain a larger electrostatic capacity than the above-mentioned tantalum electrolytic capacitor, and is widely used in power supply circuits and the like.

【0005】さらに、上記の電解コンデンサのほかに
も、小型大容量コンデンサとして、積層セラミックコン
デンサが広く用いられている。この積層セラミックコン
デンサは周波数特性が良好であること、絶縁抵抗が高い
こと、単位体積当たりの静電容量が大きいことなどの特
徴を有している。
In addition to the above-mentioned electrolytic capacitor, a monolithic ceramic capacitor is widely used as a small-sized large-capacity capacitor. This monolithic ceramic capacitor has features such as good frequency characteristics, high insulation resistance, and large capacitance per unit volume.

【0006】[0006]

【発明が解決しようとする課題】しかし、タンタル電解
コンデンサにおいては、タンタルの地金が高価であるた
め、製品であるコンデンサが高価なものになるという問
題点があり、また、構造的に単一酸化物層を誘電体層に
使用しているため、誘電体層を高誘電率化することが困
難であり、大容量化には限界があるという問題点があ
る。
However, in the tantalum electrolytic capacitor, there is a problem in that the tantalum metal is expensive, so that the capacitor that is a product is expensive. Since the oxide layer is used as the dielectric layer, it is difficult to increase the dielectric constant of the dielectric layer, and there is a problem that there is a limit to increase the capacity.

【0007】また、アルミニウム電解コンデンサにおい
ては、アルミニウムの陽極酸化膜を誘電体層として利用
しているが、漏れ電流が大きく、寿命が短いという問題
点がある。
Further, in the aluminum electrolytic capacitor, the anodic oxide film of aluminum is used as the dielectric layer, but there is a problem that the leakage current is large and the life is short.

【0008】さらに、上記のいずれの電解コンデンサに
も極性があり、電気、電子回路に組み込む工程で、その
方向(極性)を識別して組み込まなければならないた
め、実装工程での作業性が悪いという問題点がある。
Further, all of the above electrolytic capacitors have polarities, and the direction (polarity) of the electrolytic capacitors must be identified in the process of assembling into an electric or electronic circuit, so that the workability in the mounting process is poor. There is a problem.

【0009】また、積層セラミックコンデンサにおいて
は、小型、大容量化を図るために、誘電体の厚みを薄く
する試みがなされているが、1μmを下回る誘電体の厚
さで良好な積層構造を実現することはできていない。
In the monolithic ceramic capacitor, attempts have been made to reduce the thickness of the dielectric in order to reduce the size and increase the capacity, but a good laminated structure is realized with a dielectric thickness of less than 1 μm. I can't do it.

【0010】そこで本発明の目的は、上記問題点を解決
するものであり、複雑な製造工程を必要とせず、生産性
に優れ、かつ、小型で大容量のコンデンサとその製造方
法を提供することを目的とする。
Therefore, an object of the present invention is to solve the above problems, and to provide a small-capacity large-capacity capacitor which is excellent in productivity without requiring a complicated manufacturing process and a manufacturing method thereof. With the goal.

【0011】[0011]

【課題を解決するための手段】本発明は、請求項1にお
いて、コンデンサは、チタンを主成分とする金属よりな
る多孔性の焼結体と、該焼結体の表面の少なくとも一部
に形成された一般式ATiO3 (但し、AはBaまたは
Sr)で表されるペロブスカイト型複合酸化物を主成分
とする誘電体膜と、該誘電体膜の表面に形成された導体
または半導体と、該導体または半導体と導通し、前記焼
結体と対向する対向電極とを備え、前記多孔性の焼結体
の気孔率が20%以上であることを特徴とするものであ
る。
According to a first aspect of the present invention, a capacitor is formed on at least a part of a surface of a porous sintered body made of a metal containing titanium as a main component. A dielectric film mainly composed of a perovskite-type complex oxide represented by the general formula ATiO 3 (where A is Ba or Sr), a conductor or semiconductor formed on the surface of the dielectric film, It is characterized in that the porous sintered body is provided with a counter electrode which is electrically connected to a conductor or a semiconductor and faces the sintered body, and the porosity of the porous sintered body is 20% or more.

【0012】また、請求項2において、コンデンサの製
造方法は、チタンを主成分とする金属よりなる多孔性の
焼結体を、少なくともストロンチウムまたはバリウムを
0.1モル/リットル以上含有するpH13以上の水溶
液に浸漬して、100℃以上の温度を加えて水熱処理す
ることにより、前記焼結体の表面に誘電体膜として、一
般式ATiO3 (但し、AはBaまたはSr)で表され
るペロブスカイト型複合酸化物膜を形成した後、該ペロ
ブスカイト型複合酸化物膜の表面に導体または半導体の
電極を形成し、その後、該電極と導通し、前記焼結体と
対向する対向電極を形成することを特徴とするものであ
る。
According to a second aspect of the present invention, in the method for producing a capacitor, a porous sintered body made of a metal containing titanium as a main component is used, and the porous sintered body has a pH of 13 or more containing at least 0.1 mol / liter of strontium or barium. A perovskite represented by the general formula ATiO 3 (where A is Ba or Sr) is formed as a dielectric film on the surface of the sintered body by immersing in an aqueous solution and applying hydrothermal treatment at a temperature of 100 ° C. or higher. Forming a complex-type composite oxide film, forming a conductor or semiconductor electrode on the surface of the perovskite-type complex oxide film, and then forming a counter electrode electrically connected to the electrode and facing the sintered body. It is characterized by.

【0013】また、請求項3において、コンデンサの製
造方法は、焼結体を水溶液に浸漬して水熱処理する工程
において、前記水溶液中に配設された電極と前記焼結体
の間に通電する電解処理を、前記水熱処理とともに行う
ことを特徴とするものである。
According to a third aspect of the present invention, in the method for manufacturing a capacitor, in the step of immersing the sintered body in an aqueous solution and subjecting it to hydrothermal treatment, electricity is applied between the electrode arranged in the aqueous solution and the sintered body. The electrolytic treatment is performed together with the hydrothermal treatment.

【0014】また、請求項4において、コンデンサの製
造方法は、チタンを主成分とする多孔性の焼結体は、平
均粒径150μm以下の金属粉末を真空度1×10-4
orr以下の真空中で、500〜1000℃の温度で焼
結させたものであることを特徴とするものである。
According to a fourth aspect of the present invention, in the method for producing a capacitor, the porous sintered body containing titanium as a main component is made of metal powder having an average particle size of 150 μm or less and a vacuum degree of 1 × 10 −4 t.
It is characterized by being sintered at a temperature of 500 to 1000 ° C. in a vacuum of orr or lower.

【0015】[0015]

【作用】本発明のコンデンサにおいては、チタンを主成
分とする金属よりなる多孔性の焼結体の表面に、一般式
ATiO3 (但し、AはBaまたはSr)で表されるペ
ロブスカイト型複合酸化物を主成分とする誘電体膜が形
成され、さらにこの誘電体膜上に導体または半導体から
なる電極が形成されているため、焼結体を大型化するこ
となく、電極となる焼結体の表面積、および導体または
半導体からなる電極の表面積を増大させることが可能に
なる。したがって、コンデンサ全体を大型化することな
く、大きな静電容量を実現することができる。
In the capacitor of the present invention, the perovskite-type composite oxide represented by the general formula ATiO 3 (A is Ba or Sr) is formed on the surface of the porous sintered body made of a metal containing titanium as a main component. Since a dielectric film containing a substance as a main component is formed, and an electrode made of a conductor or a semiconductor is further formed on the dielectric film, the sintered body serving as an electrode can be formed without increasing the size of the sintered body. It is possible to increase the surface area and the surface area of electrodes made of conductors or semiconductors. Therefore, a large capacitance can be realized without increasing the size of the entire capacitor.

【0016】そして、多孔性の焼結体においては、その
気孔率を20%以上とすることにより、実質的な比表面
積が大きくなり、静電容量が増す。また、誘電体膜の成
膜や導体または半導体からなる電極の形成を容易に行う
ことができる、また、本発明のコンデンサの製造方法に
おいては、焼結体を、所定の条件下で水熱処理を施すこ
とにより、容易かつ確実に、任意の形状の焼結体表面に
誘電特性に優れたペロブスカイト複合酸化物を形成する
ことができる。
When the porosity of the porous sintered body is 20% or more, the substantial specific surface area is increased and the capacitance is increased. Further, it is possible to easily form a dielectric film or an electrode made of a conductor or a semiconductor. Further, in the method for producing a capacitor of the present invention, the sintered body is hydrothermally treated under predetermined conditions. By applying, it is possible to easily and reliably form the perovskite complex oxide having excellent dielectric properties on the surface of the sintered body having an arbitrary shape.

【0017】さらに、焼結体を水熱処理する工程におい
て、前記水熱処理液(アルカリ性水溶液)中に電極を浸
漬し、焼結体と電極との間に通電する電解処理を水熱処
理と同時に施すことにより、さらに効率よくペロブスカ
イト複合酸化物を形成することができる。
Further, in the step of hydrothermally treating the sintered body, the electrode is immersed in the hydrothermal treatment solution (alkaline aqueous solution), and an electrolytic treatment in which electricity is applied between the sintered body and the electrode is simultaneously applied with the hydrothermal treatment. Thereby, the perovskite composite oxide can be formed more efficiently.

【0018】[0018]

【実施例】本発明の実施例を図面を参照して説明する 図1は本発明のコンデンサの多孔性の焼結体部分の拡大
断面図である。1は埋設されたチタンワイヤー、2は多
孔性の焼結体、3は焼結体表面に形成された誘電体膜、
4は誘電体膜表面に形成された導体または半導体からな
る電極、をそれぞれ示している。
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged cross-sectional view of a porous sintered body portion of a capacitor of the present invention. 1 is a buried titanium wire, 2 is a porous sintered body, 3 is a dielectric film formed on the surface of the sintered body,
Reference numeral 4 denotes an electrode made of a conductor or a semiconductor formed on the surface of the dielectric film.

【0019】図2は本発明のコンデンサの断面図であ
る。1はチタンワイヤー、5は多孔性の焼結体からなる
コンデンサ素子、6はグラファイト層、7は銀電極層、
8はリード線、9ははんだ、10は外装樹脂、をそれぞ
れ示している。
FIG. 2 is a sectional view of the capacitor of the present invention. 1 is a titanium wire, 5 is a capacitor element made of a porous sintered body, 6 is a graphite layer, 7 is a silver electrode layer,
Reference numeral 8 is a lead wire, 9 is a solder, and 10 is an exterior resin.

【0020】図3は多孔性の焼結体に誘電体膜を形成す
る装置の概略図である。2は多孔性の焼結体、11はフ
ッ素樹脂製ビーカー、12は水熱処理溶液、13は白金
板、14はオートクレーブ、15は直流電源、16は白
金線、をそれぞれ示している。 (実施例1)ま
ず、チタン金属からなる多孔性の焼結体を得た。すなわ
ち、平均粒径50μmのチタン金属粉末を円柱状に成形
した。この際、一方の電極取り出しリード線としてチタ
ンワイヤーの一部をチタン金属粉末に埋設して成形し
た。その後、この成形体を5×10-6〜3×10-7to
rrの真空中、800℃の温度で焼成して、多孔性の焼
結体を得た。
FIG. 3 is a schematic view of an apparatus for forming a dielectric film on a porous sintered body. 2 is a porous sintered body, 11 is a fluororesin beaker, 12 is a hydrothermal treatment solution, 13 is a platinum plate, 14 is an autoclave, 15 is a DC power supply, and 16 is a platinum wire. Example 1 First, a porous sintered body made of titanium metal was obtained. That is, a titanium metal powder having an average particle size of 50 μm was formed into a cylindrical shape. At this time, a part of the titanium wire was embedded in titanium metal powder and molded as a lead wire for taking out one of the electrodes. Then, this molded body was subjected to 5 × 10 −6 to 3 × 10 −7 to
It was fired at a temperature of 800 ° C. in a vacuum of rr to obtain a porous sintered body.

【0021】次に、この多孔性の焼結体を、0. 5モル
/リットルの水酸化ストロンチウム水溶液を水酸化ナト
リウムを用いてpH14に調整した水熱処理溶液に浸漬
し、150℃の温度で60分間保持して水熱処理を行
い、図1に示すように、多孔性の焼結体2の表面に厚さ
約0. 3μmのチタン酸ストロンチウム多結晶薄膜から
なる誘電体膜3を直接形成した。
Next, the porous sintered body was immersed in a hydrothermal treatment solution in which a 0.5 mol / liter strontium hydroxide aqueous solution was adjusted to pH 14 with sodium hydroxide, and the temperature was raised to 60 ° C. at 60 ° C. A hydrothermal treatment was carried out by holding for a minute, and as shown in FIG. 1, a dielectric film 3 made of a strontium titanate polycrystal thin film having a thickness of about 0.3 μm was directly formed on the surface of the porous sintered body 2.

【0022】さらに、前記チタン酸ストロンチウム薄膜
を形成した焼結体を硝酸マンガン溶液に浸漬し、その
後、温度200℃〜400℃で熱処理してチタン酸スト
ロンチウム薄膜の表面に二酸化マンガン層を形成し、多
孔性の焼結体2、誘電体膜3、導体または半導体からな
る電極4およびチタンワイヤー1で構成されたコンデン
サ素子5を作製した。
Further, the sintered body on which the strontium titanate thin film is formed is dipped in a manganese nitrate solution and then heat-treated at a temperature of 200 to 400 ° C. to form a manganese dioxide layer on the surface of the strontium titanate thin film, A capacitor element 5 composed of a porous sintered body 2, a dielectric film 3, an electrode 4 made of a conductor or a semiconductor and a titanium wire 1 was produced.

【0023】その後、通常の固体電解コンデンサと同
様、図2に示すように、順次、コンデンサ素子5に対
し、グラファイト層6を設け、さらに、銀電極層7を設
けて対向電極を形成し、他方のリード線8をはんだ9に
よって取り付け、外装樹脂10を施してコンデンサとし
た。
Thereafter, as in the case of a normal solid electrolytic capacitor, as shown in FIG. 2, a graphite layer 6 is sequentially provided on a capacitor element 5, and a silver electrode layer 7 is further provided to form a counter electrode, while the other electrode is formed. The lead wire 8 was attached by the solder 9 and the exterior resin 10 was applied to form a capacitor.

【0024】このようにして作製したコンデンサについ
て、静電容量、tanδ、絶縁抵抗を測定したところ、
以下のような結果が得られた。
When the capacitance, tan δ, and insulation resistance of the capacitor thus manufactured were measured,
The following results were obtained.

【0025】 静電容量(周波数1kHz,電圧1Vrms):10.2μF tanδ(同上) : 5.6% 絶縁抵抗(電圧6.3Vdc,120秒後) : 1.3×107 Ω (実施例2)まず、実施例1と同様の方法で多孔性の焼
結体を得た。
Capacitance (frequency 1 kHz, voltage 1 Vrms): 10.2 μF tan δ (same as above): 5.6% Insulation resistance (voltage 6.3 Vdc, after 120 seconds): 1.3 × 10 7 Ω (Example 2) ) First, a porous sintered body was obtained in the same manner as in Example 1.

【0026】そして、図3に示す装置を用いて、この多
孔性の焼結体に電解処理により誘電体膜を形成した。す
なわち、0.5モル/リットルの水酸化バリウム水溶液
を、水酸化ナトリウムを用いてpH13.5に調整した
水熱処理溶液12を準備した。次に、フッ素樹脂製ビー
カー11内で、この水熱処理溶液12に多孔性の焼結体
2および白金板13を浸漬した。それとともに、オート
クレーブ14を密閉したときにも、外部の直流電源15
から、多孔性の焼結体2および白金板13に電力を供給
することができるように、あらかじめ配線しておいた一
対のフッ素樹脂コートを施した白金線16を、多孔性焼
結体2および白金板13に接続した。そして、フッ素樹
脂製ビーカー11内の水熱処理溶液12中に、多孔性の
焼結体2と白金板13が浸漬された状態でオートクレー
ブ14を密閉した。
Then, using the apparatus shown in FIG. 3, a dielectric film was formed on this porous sintered body by electrolytic treatment. That is, a hydrothermal treatment solution 12 in which a 0.5 mol / liter aqueous barium hydroxide solution was adjusted to pH 13.5 with sodium hydroxide was prepared. Next, in the fluororesin beaker 11, the porous sintered body 2 and the platinum plate 13 were immersed in the hydrothermal treatment solution 12. At the same time, even when the autoclave 14 is sealed, the external DC power source 15
In order to supply electric power to the porous sintered body 2 and the platinum plate 13, a pair of fluorocarbon resin-coated platinum wires 16 that are pre-wired are connected to the porous sintered body 2 and It was connected to a platinum plate 13. Then, the autoclave 14 was sealed while the porous sintered body 2 and the platinum plate 13 were immersed in the hydrothermal treatment solution 12 in the fluororesin beaker 11.

【0027】この状態で150℃まで昇温し、その後6
0分間、この温度に保持して、水熱処理を行うと同時
に、多孔性の焼結体2と白金板13の間に直流電圧10
Vを印加して定電圧電解処理を施した。次に、処理後の
多孔性の焼結体2を蒸留水中で十分に超音波洗浄した
後、120℃で60分間乾燥した。
In this state, the temperature is raised to 150 ° C. and then 6
While maintaining this temperature for 0 minutes to perform the hydrothermal treatment, a DC voltage of 10 is applied between the porous sintered body 2 and the platinum plate 13.
A constant voltage electrolysis treatment was performed by applying V. Next, the treated porous sintered body 2 was sufficiently ultrasonically washed in distilled water and then dried at 120 ° C. for 60 minutes.

【0028】この方法により、多孔性の焼結体2の全表
面に誘電体膜である厚さ1.0μmのチタン酸バリウム
多結晶薄膜を形成した。なお、実施例1のような電解処
理を伴わない水熱処理のみの誘電体膜の形成方法では、
膜厚約0. 5μm以上まで形成させるのに、数時間から
数十時間を要するのに対して、この実施例2のように、
電解処理を伴う誘電体膜の形成方法によれば、膜厚が数
μmの誘電体膜を数時間で形成することができた。
By this method, a barium titanate polycrystal thin film having a thickness of 1.0 μm, which is a dielectric film, was formed on the entire surface of the porous sintered body 2. In addition, in the method for forming a dielectric film only by hydrothermal treatment without electrolytic treatment as in Example 1,
While it takes several hours to several tens of hours to form a film having a thickness of about 0.5 μm or more, as in Example 2,
According to the method for forming a dielectric film involving electrolytic treatment, a dielectric film having a thickness of several μm could be formed in a few hours.

【0029】このようにして、誘電体膜を形成した後、
実施例1と同様な工法によってコンデンサを作製した、
そして、静電容量、tanδ、絶縁抵抗を測定したとこ
ろ、以下のような結果が得られた。
After forming the dielectric film in this way,
A capacitor was manufactured by the same method as in Example 1,
Then, when the electrostatic capacity, tan δ, and insulation resistance were measured, the following results were obtained.

【0030】 静電容量(周波数1kHz,電圧1Vrms):6.1μF tanδ(同上) :7.4% 絶縁抵抗(電圧6. 3Vdc,120秒後) :1.1×107 Ω (実施例3)まず、チタン金属からなり、種々の気孔率
を有する多孔性の焼結体を得た。すなわち、平均粒径5
0μmのチタン金属粉末を円柱状に、表1に示す密度に
てそれぞれ成形した。この際、一方の取り出しリード線
として、チタンワイヤーの一部をチタン金属粉末に埋設
して成形した。この成形体を、5×10-6torr以下
の真空中で、表1に示す焼成温度で焼成して、多孔性の
焼結体を得た。得られた焼結体の密度を測定して気孔率
を算出した。
Capacitance (frequency 1 kHz, voltage 1 Vrms): 6.1 μF tan δ (same as above): 7.4% Insulation resistance (voltage 6.3 Vdc, after 120 seconds): 1.1 × 10 7 Ω (Example 3) ) First, porous sintered bodies made of titanium metal and having various porosities were obtained. That is, the average particle size is 5
A 0 μm titanium metal powder was formed into a columnar shape at the density shown in Table 1. At this time, a part of the titanium wire was embedded in titanium metal powder and molded as one of the lead wires. This compact was fired at a firing temperature shown in Table 1 in a vacuum of 5 × 10 −6 torr or less to obtain a porous sintered body. The porosity was calculated by measuring the density of the obtained sintered body.

【0031】次に、この多孔性の焼結体の表面に誘電体
膜を形成した。すなわち、0. 5モル/リットルの水酸
化バリウムまたは水酸化ストロンチウム、さらに水酸化
バリウムと水酸化ストロンチウムを0.25モル/リッ
トルずつ混合した水溶液を、水酸化ナトリウムを用いて
pH13.5に調整した水熱処理溶液を準備した。次
に、実施例2と同様にして、水熱処理、定電圧電解処理
を施して多孔性の焼結体の表面にチタン酸ストロンチウ
ム薄膜を形成し、その後、超音波洗浄した後、乾燥を行
った。
Next, a dielectric film was formed on the surface of this porous sintered body. That is, 0.5 mol / liter of barium hydroxide or strontium hydroxide, and an aqueous solution of barium hydroxide and strontium hydroxide mixed at 0.25 mol / liter were adjusted to pH 13.5 with sodium hydroxide. A hydrothermal treatment solution was prepared. Next, in the same manner as in Example 2, hydrothermal treatment and constant voltage electrolysis treatment were performed to form a strontium titanate thin film on the surface of the porous sintered body, and then ultrasonic cleaning was performed and then drying was performed. .

【0032】このようにして誘電体膜を形成した後、さ
らに、電極として、実施例1と同様にして、誘電体膜の
表面に半導体の二酸化マンガン層を形成し、コンデンサ
素子を作製した。
After forming the dielectric film in this way, a manganese dioxide layer of semiconductor was formed on the surface of the dielectric film as an electrode in the same manner as in Example 1 to manufacture a capacitor element.

【0033】その後、通常の固体電解コンデンサと同様
に、順次、グラファイト層、銀電極層を設けて外部電極
を形成し、他方のリード線をはんだによって取り付け、
外装樹脂を施してコンデンサとした。
Then, similarly to a normal solid electrolytic capacitor, a graphite layer and a silver electrode layer are sequentially provided to form an external electrode, and the other lead wire is attached by soldering,
Exterior resin was applied to make a capacitor.

【0034】以上のようにして作成したコンデンサにつ
いて静電容量(周波数1kHz,電圧1Vrms)、t
anδ(周波数1kHz,電圧1Vrms)、絶縁抵抗
(電圧6.3Vdc,120秒後)を測定したところ、
表1のような結果が得られた。なお、試料番号に*印を
付したものは本発明の範囲外である。
The capacitance (frequency 1 kHz, voltage 1 Vrms), t
When an δ (frequency 1 kHz, voltage 1 Vrms) and insulation resistance (voltage 6.3 Vdc, after 120 seconds) were measured,
The results shown in Table 1 were obtained. The sample numbers with * are out of the scope of the present invention.

【0035】[0035]

【表1】 [Table 1]

【0036】表1から明らかなように、多孔性の焼結体
の気孔率は20%以上であることが望ましい。これより
小さな気孔率を持つ多孔性の焼結体では実質的な比表面
積が小さくなるため、同じ組成の誘電体膜で得られるコ
ンデンサの静電容量が小さくなり好ましくない。
As is clear from Table 1, the porosity of the porous sintered body is preferably 20% or more. Since a porous sintered body having a porosity smaller than this has a substantially small specific surface area, the capacitance of a capacitor obtained by a dielectric film having the same composition becomes small, which is not preferable.

【0037】(実施例4)平均粒径がそれぞれ30μ
m、50μm、150μm、300μmのチタン金属粉
末を用い、表2に示す種々の焼成温度と真空度で、それ
以外は実施例1と同様な工法によって、多孔性の焼結体
を作製した。
(Example 4) The average particle size is 30 μm
Porous sintered bodies were produced using titanium metal powders of m, 50 μm, 150 μm, and 300 μm at various firing temperatures and vacuum degrees shown in Table 2 and by the same method as in Example 1 except for the above.

【0038】さらに、チタン酸ストロンチウムからなる
誘電体膜の形成からコンデンサの作製まで、実施例2と
同様な電解処理を伴う誘電体膜の形成方法により、コン
デンサを作成した。
Furthermore, from the formation of the dielectric film made of strontium titanate to the production of the capacitor, a capacitor was produced by the same method of forming the dielectric film as in Example 2 involving the electrolytic treatment.

【0039】表2にこれらのコンデンサの測定結果を示
す。なお、試料番号に*印を付したものは本発明の範囲
外である。
Table 2 shows the measurement results of these capacitors. The sample numbers with * are out of the scope of the present invention.

【0040】[0040]

【表2】 [Table 2]

【0041】表2から明らかなように、多孔性焼結体を
作成するのに使用するチタン金属粉末の平均粒径は15
0μm以下であることが望ましい。これより大きな平均
粒径を持つ粉末では焼結体の表面積が小さくなり、得ら
れるコンデンサの静電容量が小さくなり好ましくない。
As is clear from Table 2, the titanium metal powder used for producing the porous sintered body has an average particle size of 15
It is desirable that the thickness be 0 μm or less. If the powder has an average particle size larger than this, the surface area of the sintered body becomes small and the capacitance of the obtained capacitor becomes small, which is not preferable.

【0042】また、焼成する際には1×10-4torr
以下の真空度であることが望ましい。これより低い真空
度では、焼結の際に金属表面に酸化物等の反応が生じ、
tanδが上昇するために好ましくない。
When firing, 1 × 10 -4 torr
The following vacuum degree is desirable. At a vacuum degree lower than this, reactions such as oxides occur on the metal surface during sintering,
It is not preferable because tan δ increases.

【0043】さらに、焼成温度は500〜1000℃で
あることが好ましい。500℃を下回る低い温度では充
分な焼結体が得られにくく、1000℃を超える場合で
は焼結体の表面積が小さくなって、得られるコンデンサ
の静電容量が小さくなり好ましくない。
Further, the firing temperature is preferably 500 to 1000 ° C. If the temperature is lower than 500 ° C., it is difficult to obtain a sufficient sintered body, and if the temperature is higher than 1000 ° C., the surface area of the sintered body becomes small and the capacitance of the obtained capacitor becomes small, which is not preferable.

【0044】なお、本実施例においては、バリウムやス
トロンチウムのイオン源として水酸化物を用いたが、こ
れに限定されるべきものではなく、pH調整剤について
も水酸化ナトリウムに限らず、他の水酸化物、例えば水
酸化カリウムや水酸化リチウム等を用いることが可能で
ある。
In this example, hydroxide was used as the ion source of barium or strontium, but it should not be limited to this, and the pH adjuster is not limited to sodium hydroxide, and other It is possible to use hydroxides such as potassium hydroxide or lithium hydroxide.

【0045】また、誘電体膜上に形成する電極も、本実
施例で用いた半導体の二酸化マンガンだけでなく、他の
導体あるいは半導体、例えば電解液や有機物などを用い
てもよい。
The electrode formed on the dielectric film may be not only the semiconductor manganese dioxide used in this embodiment, but also another conductor or semiconductor such as an electrolytic solution or an organic substance.

【0046】[0046]

【発明の効果】以上の説明で明らかなように、本発明の
コンデンサは、多孔性の焼結体、焼結体の表面の誘電体
膜、誘電体膜の表面の導体または半導体、導体または半
導体膜と導通する対向電極とを備えて構成されているた
め、小型で大容量のコンデンサが実現できる。そして、
誘電体膜がペロブスカイト型複合酸化物を主成分とする
ために、単一酸化物に比べて誘電率が大きいものが得ら
れ、より大容量のコンデンサを得ることができる。
As is apparent from the above description, the capacitor of the present invention comprises a porous sintered body, a dielectric film on the surface of the sintered body, a conductor or semiconductor on the surface of the dielectric film, a conductor or semiconductor. Since it is composed of the film and the counter electrode that is electrically connected to the film, a small-sized and large-capacity capacitor can be realized. And
Since the dielectric film contains the perovskite-type composite oxide as a main component, a dielectric film having a larger dielectric constant than that of a single oxide can be obtained, and a capacitor having a larger capacity can be obtained.

【0047】また、その製造方法は、多孔性の焼結体の
上に直接誘電体膜を形成することができるため、複雑な
製造工程を必要とせず容易に低コストで製造することが
可能になる。
Further, in the manufacturing method, since the dielectric film can be directly formed on the porous sintered body, it is possible to easily manufacture at a low cost without requiring a complicated manufacturing process. Become.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明のコンデンサの多孔性の焼結体の部分断
面図である。
1 is a partial cross-sectional view of a porous sintered body of a capacitor of the present invention.

【図2】本発明のコンデンサの断面図である。FIG. 2 is a sectional view of a capacitor of the present invention.

【図3】多孔性の焼結体に誘電体膜を形成する装置の概
略図である。
FIG. 3 is a schematic view of an apparatus for forming a dielectric film on a porous sintered body.

【符号の説明】[Explanation of symbols]

1 チタンワイヤ− 2 多孔性の焼結体 3 誘電体膜 4 導体または半導体からなる電極 5 コンデンサ素子 6 グラファイト層 7 銀電極層 8 リード線 9 はんだ 10 外装樹脂 1 Titanium Wire-2 Porous Sintered Body 3 Dielectric Film 4 Electrode Made of Conductor or Semiconductor 5 Capacitor Element 6 Graphite Layer 7 Silver Electrode Layer 8 Lead Wire 9 Solder 10 Exterior Resin

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】 チタンを主成分とする金属よりなる多孔
性の焼結体と、該焼結体の表面の少なくとも一部に形成
された一般式ATiO3 (但し、AはBaまたはSr)
で表されるペロブスカイト型複合酸化物を主成分とする
誘電体膜と、該誘電体膜の表面に形成された導体または
半導体と、該導体または半導体と導通し、前記焼結体と
対向する対向電極とを備え、前記多孔性の焼結体の気孔
率が20%以上であることを特徴とするコンデンサ。
1. A porous sintered body made of a metal containing titanium as a main component, and a general formula ATiO 3 (where A is Ba or Sr) formed on at least a part of the surface of the sintered body.
And a conductor film or a semiconductor film formed on the surface of the dielectric film, a conductor film or a semiconductor film formed on the surface of the dielectric film film, and a conductor film or a semiconductor film formed on the surface of the dielectric film film. A capacitor comprising an electrode, wherein the porosity of the porous sintered body is 20% or more.
【請求項2】 チタンを主成分とする金属よりなる多孔
性の焼結体を、少なくともストロンチウムまたはバリウ
ムを0. 1モル/リットル以上含有するpH13以上の
水溶液に浸漬して、100℃以上の温度を加えて水熱処
理することにより、前記焼結体の表面に誘電体膜とし
て、一般式ATiO3 (但し、AはBaまたはSr)で
表されるペロブスカイト型複合酸化物膜を形成した後、
該ペロブスカイト型複合酸化物膜の表面に導体または半
導体の電極を形成し、その後、該電極と導通し、前記焼
結体と対向する対向電極を形成することを特徴とするコ
ンデンサの製造方法。
2. A porous sintered body made of a metal containing titanium as a main component is immersed in an aqueous solution containing at least 0.1 mol / liter of strontium or barium and having a pH of 13 or more, and a temperature of 100 ° C. or more. And hydrothermal treatment to form a perovskite-type complex oxide film represented by the general formula ATiO 3 (where A is Ba or Sr) as a dielectric film on the surface of the sintered body,
A method of manufacturing a capacitor, comprising forming a conductor or semiconductor electrode on the surface of the perovskite type complex oxide film, and then forming a counter electrode which is electrically connected to the electrode and faces the sintered body.
【請求項3】 焼結体を水溶液に浸漬して水熱処理する
工程において、前記水溶液中に配設された電極と前記焼
結体の間に通電する電解処理を、前記水熱処理とともに
行うことを特徴とする請求項2記載のコンデンサの製造
方法。
3. In the step of immersing the sintered body in an aqueous solution for hydrothermal treatment, an electrolytic treatment in which an electric current is applied between the electrode arranged in the aqueous solution and the sintered body is performed together with the hydrothermal treatment. The method of manufacturing a capacitor according to claim 2, wherein the capacitor is manufactured.
【請求項4】 チタンを主成分とする多孔性の焼結体
は、平均粒径150μm以下の金属粉末を真空度1×1
-4torr以下の真空中で、500〜1000℃の温
度で焼結させたものであることを特徴とする請求項2記
載のコンデンサの製造方法。
4. The porous sintered body containing titanium as a main component is made of metal powder having an average particle size of 150 μm or less and a vacuum degree of 1 × 1.
The method for manufacturing a capacitor according to claim 2, wherein the capacitor is sintered at a temperature of 500 to 1000 ° C in a vacuum of 0 -4 torr or less.
JP16105195A 1995-06-27 1995-06-27 Capacitor and its manufacture Pending JPH0917685A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP16105195A JPH0917685A (en) 1995-06-27 1995-06-27 Capacitor and its manufacture
US08/673,176 US5790368A (en) 1995-06-27 1996-06-26 Capacitor and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16105195A JPH0917685A (en) 1995-06-27 1995-06-27 Capacitor and its manufacture

Publications (1)

Publication Number Publication Date
JPH0917685A true JPH0917685A (en) 1997-01-17

Family

ID=15727681

Family Applications (1)

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

Country Link
JP (1) JPH0917685A (en)

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EP1644947A2 (en) * 2003-07-10 2006-04-12 Showa Denko K.K. Jig for producing capacitor, production method for capacitor and capacitor
WO2012124584A1 (en) * 2011-03-15 2012-09-20 三洋電機株式会社 Solid electrolytic capacitor and method of producing same
US8758454B2 (en) 2011-03-29 2014-06-24 Sanyo Electric Co., Ltd. Solid electrolytic capacitor and method for manufacturing the same
JP5757867B2 (en) * 2009-06-15 2015-08-05 東洋アルミニウム株式会社 Electrode material for aluminum electrolytic capacitor and method for producing the same
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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1644947A2 (en) * 2003-07-10 2006-04-12 Showa Denko K.K. Jig for producing capacitor, production method for capacitor and capacitor
EP1644947A4 (en) * 2003-07-10 2007-08-22 Showa Denko Kk Jig for producing capacitor, production method for capacitor and capacitor
US7819928B2 (en) 2003-07-10 2010-10-26 Showa Denko K.K. Jig for producing capacitor, production method for capacitor and capacitor
JP5757867B2 (en) * 2009-06-15 2015-08-05 東洋アルミニウム株式会社 Electrode material for aluminum electrolytic capacitor and method for producing the same
WO2012124584A1 (en) * 2011-03-15 2012-09-20 三洋電機株式会社 Solid electrolytic capacitor and method of producing same
US9431178B2 (en) 2011-03-15 2016-08-30 Panasonic Intellectual Property Management Co., Ltd. Solid electrolytic capacitor and method of producing same
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US8758454B2 (en) 2011-03-29 2014-06-24 Sanyo Electric Co., Ltd. Solid electrolytic capacitor and method for manufacturing the same
WO2016137057A1 (en) * 2015-02-26 2016-09-01 경북대학교 산학협력단 Method for preparing aluminum foil for electrolytic capacitor, aluminum foil having high dielectric constant, electrolytic capacitor comprising same, and apparatus for preparing aluminum foil

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