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JPH11111575A - Manufacture of porous anode in solid electrolytic capacitor - Google Patents

Manufacture of porous anode in solid electrolytic capacitor

Info

Publication number
JPH11111575A
JPH11111575A JP9275477A JP27547797A JPH11111575A JP H11111575 A JPH11111575 A JP H11111575A JP 9275477 A JP9275477 A JP 9275477A JP 27547797 A JP27547797 A JP 27547797A JP H11111575 A JPH11111575 A JP H11111575A
Authority
JP
Japan
Prior art keywords
porous anode
anode body
sintering
molding
solid electrolytic
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
JP9275477A
Other languages
Japanese (ja)
Inventor
Kiyoshi Hirota
潔 廣田
Hiroshi Kita
広志 喜多
Yoshiki Hashimoto
芳樹 橋本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP9275477A priority Critical patent/JPH11111575A/en
Publication of JPH11111575A publication Critical patent/JPH11111575A/en
Pending legal-status Critical Current

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  • Powder Metallurgy (AREA)

Abstract

PROBLEM TO BE SOLVED: To reduce oxygen concentration of a porous anode body and a defect in dielectric oxide coating by pressurized-molding tantalum powder under a condition where an anode lead is implanted to form a molding, sintering the molding coexisting with a strong oxygen affinity materials to constitute a porous anode body and acid-cleaning it. SOLUTION: Tantalum powder is pressurized-molded to form a molding under a condition where an anode lead is implanted. Next, a porous anode body is constituted by sintering a molding coexisting with carbon and magnesium. In this case, the molding is sintered in high temperature and high vacuum. Thereafter, the porous anode body is cleaned with hydrochloric acid to remove excess carbon and magnesium. Thereby, a porous anode body having a low oxygen concentration is produced and a defect in dielectric oxide coating is reduced.

Description

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

【0001】[0001]

【発明の属する技術分野】本発明は固体電解コンデンサ
における多孔質陽極体の製造方法に関するものである。
The present invention relates to a method for manufacturing a porous anode body in a solid electrolytic capacitor.

【0002】[0002]

【従来の技術】一般に、タンタル固体電解コンデンサ
は、弁作用金属からなる陽極導出線を植設した状態でタ
ンタル粉末を加圧成形することにより成形体を形成し、
かつこの成形体を高温高真空中で焼結することにより多
孔質陽極体を構成し、その後、この多孔質陽極体の表面
に誘電体酸化皮膜層、半導体層、カーボン層、銀ペイン
ト層を順次形成してコンデンサ素子を構成している。こ
の多孔質陽極体の固体電解コンデンサへの適用において
は多孔質陽極体中の不純物濃度、特に酸素濃度が特性に
及ぼす影響は非常に重要となるもので、つまり多孔質陽
極体中の全酸素濃度が3000ppm以上の場合、多孔
質陽極体を陽極酸化することにより形成した誘電体酸化
皮膜層中には、特に50V以上の皮膜形成電圧において
は、皮膜欠陥が多数発生する。
2. Description of the Related Art In general, a tantalum solid electrolytic capacitor is formed by pressing and molding tantalum powder in a state where an anode lead wire made of a valve action metal is planted.
A sintered body is sintered at a high temperature and a high vacuum to form a porous anode body, and then a dielectric oxide film layer, a semiconductor layer, a carbon layer, and a silver paint layer are sequentially formed on the surface of the porous anode body. It forms the capacitor element. In applying this porous anode body to a solid electrolytic capacitor, the effect of the impurity concentration in the porous anode body, particularly the oxygen concentration, on the characteristics is very important, that is, the total oxygen concentration in the porous anode body. Is 3000 ppm or more, a large number of film defects occur in the dielectric oxide film layer formed by anodizing the porous anode body, particularly at a film formation voltage of 50 V or more.

【0003】この欠陥数と漏れ電流の間には、図2に示
すような正の相関関係があり、欠陥数が多いほど漏れ電
流が多いもので、この結果、酸素濃度の増大は漏れ電流
の増大を招く。また、欠陥数が多いほど寿命特性も悪化
するもので、従来は多孔質陽極体の酸素濃度を低減させ
るために、タンタル粉末を加圧成形することにより形成
した成形体を真空中で焼結することにより多孔質陽極体
を構成した後、この多孔質陽極体を焼結炉から取り出
し、改めて、真空中または不活性ガス中で焼結した温度
より低い温度で、多孔質陽極体をマグネシウムの共存下
で熱処理することにより酸素を還元するようにしてい
た。
[0003] There is a positive correlation between the number of defects and the leakage current as shown in FIG. 2. As the number of defects increases, the leakage current increases. As a result, an increase in the oxygen concentration decreases the leakage current. Cause an increase. In addition, as the number of defects increases, the life characteristics deteriorate, and conventionally, in order to reduce the oxygen concentration of the porous anode body, a compact formed by pressing and molding tantalum powder is sintered in a vacuum. After forming the porous anode body, the porous anode body is taken out of the sintering furnace, and the porous anode body is coexisted with magnesium at a temperature lower than the temperature sintered in a vacuum or an inert gas. The oxygen was reduced by heat treatment below.

【0004】[0004]

【発明が解決しようとする課題】タンタル粉末は、酸素
に対して大きな親和性を有するものであり、またタンタ
ル粉末を加圧成形することにより形成された成形体の焼
結および焼結後の大気への暴露は酸素濃度の増加を導く
ものである。近年、固体電解コンデンサの小型化、大容
量化のため、使用するタンタル粉末の高CV値化が進ん
でいる。高CV値粉末ほど粉末粒子径が小さいため、表
面積が大きい。タンタル粉末および焼結した多孔質陽極
体中の酸素量は暴露する多孔質陽極体の表面積に比例す
るため、使用するタンタル粉末が高CV値になるほど、
大気中の酸素が吸着されて、高い酸素濃度を示す。
SUMMARY OF THE INVENTION Tantalum powder has a high affinity for oxygen, and sinters a compact formed by pressure-molding the tantalum powder and the air after sintering. Exposure to oxygen leads to increased oxygen levels. In recent years, the tantalum powder used has been increasing the CV value in order to reduce the size and increase the capacity of solid electrolytic capacitors. The higher the CV value powder, the smaller the particle size of the powder and the larger the surface area. Since the amount of oxygen in the tantalum powder and the sintered porous anode body is proportional to the surface area of the porous anode body to be exposed, the higher the tantalum powder used becomes, the higher the CV value becomes.
Oxygen in the atmosphere is adsorbed and shows a high oxygen concentration.

【0005】また、従来の技術で示したように多孔質陽
極体の酸素濃度を低減させるために、真空中または不活
性ガス中で焼結した温度より低い温度で、多孔質陽極体
をマグネシウムの共存下で熱処理することにより酸素を
還元する方法は、焼結以外に熱処理工程が増えるため、
この熱処理工程の追加により、多孔質陽極体の熱処理後
の大気中への暴露回数が増えるために酸素濃度が増加す
るもので、これにより、酸素濃度低減効果は十分ではな
く、しかもコンデンサ素子の容量(CV値)が、高温の
熱履歴時間の増加に伴って減少するという問題点も有し
ていた。
Further, as shown in the prior art, in order to reduce the oxygen concentration of the porous anode body, the porous anode body is made of magnesium at a temperature lower than the sintering temperature in a vacuum or an inert gas. In the method of reducing oxygen by heat treatment in the presence of coexistence, heat treatment steps other than sintering increase,
The addition of this heat treatment step increases the number of exposures of the porous anode body to the atmosphere after the heat treatment, thereby increasing the oxygen concentration. As a result, the effect of reducing the oxygen concentration is not sufficient, and the capacity of the capacitor element is not increased. (CV value) also has a problem that it decreases with an increase in the heat history time at a high temperature.

【0006】本発明は上記従来の問題点を解決するもの
で、多孔質陽極体中の酸素濃度を低減させる効果を十分
に発揮できるとともに、誘電体酸化皮膜中の欠陥部の減
少も図れて漏れ電流を低減させることができ、これによ
り、寿命特性試験の際の信頼性を高めることができる固
体電解コンデンサにおける多孔質陽極体の製造方法を提
供することを目的とするものである。
SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems. In addition to the effect of reducing the oxygen concentration in the porous anode body, it is possible to reduce the number of defects in the dielectric oxide film and reduce the leakage. An object of the present invention is to provide a method for manufacturing a porous anode body in a solid electrolytic capacitor that can reduce the current and thereby increase the reliability in a life characteristic test.

【0007】[0007]

【課題を解決するための手段】上記目的を達成するため
に本発明の固体電解コンデンサにおける多孔質陽極体の
製造方法は、陽極リードを植設した状態でタンタル粉末
を加圧成形することにより成形体を形成し、かつこの成
形体を高温高真空中または不活性ガス中においてタンタ
ルと比べて酸素親和力の強い物質を共存させて焼結する
ことにより多孔質陽極体を構成し、さらにこの多孔質陽
極体を酸で洗浄するようにしたもので、この製造方法に
よれば、多孔質陽極体中の酸素濃度を低減させる効果を
十分に発揮できるとともに、誘電体酸化皮膜中の欠陥部
の減少も図れて漏れ電流を低減させることができ、これ
により、寿命特性試験の際の信頼性を高めることができ
るものである。
In order to achieve the above object, a method of manufacturing a porous anode body in a solid electrolytic capacitor according to the present invention comprises forming a porous anode body by pressing and molding tantalum powder with an anode lead implanted. A porous anode body is formed by forming a body and sintering the formed body in a high-temperature high-vacuum or inert gas in the presence of a substance having a higher oxygen affinity than that of tantalum, and further forming the porous anode body. The anode body is cleaned with acid. According to this manufacturing method, the effect of reducing the oxygen concentration in the porous anode body can be sufficiently exhibited, and the number of defects in the dielectric oxide film can be reduced. As a result, the leakage current can be reduced, whereby the reliability in the life characteristic test can be improved.

【0008】[0008]

【発明の実施の形態】本発明の請求項1に記載の発明
は、陽極リードを植設した状態でタンタル粉末を加圧成
形することにより成形体を形成し、かつこの成形体を高
温高真空中または不活性ガス中においてタンタルと比べ
て酸素親和力の強い物質を共存させて焼結することによ
り多孔質陽極体を構成し、さらにこの多孔質陽極体を酸
で洗浄するようにしたもので、この製造方法によれば、
焼結工程において、タンタル粉末を加圧成形することに
より形成された成形体の表面に吸着している酸素ならび
にタンタル粉末中に溶存している酸素は、酸素親和力の
強い共存物質と反応して脱酸素が行われるため、従来の
ように焼結後に改めて脱酸素熱処理を行う場合に比べ
て、酸素濃度の低い多孔質陽極体を得ることができ、か
つCV値の減少も少ない。また、前記多孔質陽極体は酸
で洗浄して余分の残渣を除去するようにしているため、
共存物質残渣による誘電体酸化皮膜中の欠陥部は減少
し、これにより、漏れ電流特性の悪化を防止することが
できる。この結果、寿命特性面においても著しい向上が
図れるものである。
DETAILED DESCRIPTION OF THE INVENTION According to the first aspect of the present invention, a compact is formed by press-forming tantalum powder in a state where an anode lead is implanted, and the compact is formed at high temperature and high vacuum. A porous anode body is formed by sintering in the presence of a substance having a higher oxygen affinity than tantalum in or in an inert gas, and the porous anode body is further washed with acid. According to this manufacturing method,
In the sintering process, oxygen adsorbed on the surface of the compact formed by pressing the tantalum powder and oxygen dissolved in the tantalum powder react with a coexisting substance having a strong oxygen affinity to desorb. Since oxygen is used, a porous anode body having a low oxygen concentration can be obtained, and the CV value does not decrease much as compared with the conventional case where deoxidation heat treatment is performed again after sintering. Further, since the porous anode body is washed with acid to remove excess residues,
Defects in the dielectric oxide film due to coexisting substance residues are reduced, thereby preventing leakage current characteristics from deteriorating. As a result, a remarkable improvement in the life characteristics can be achieved.

【0009】請求項2に記載の発明は、成形体の焼結に
おいて共存させる物質を、バナジウム、ホウ素、リチウ
ム、カルシウム、バリウム、ランタンのうちのいずれか
の物質、またはリチウム、マグネシウム、アルミニウム
のうちのいずれかの物質と、バリウム、ホウ素、カルシ
ウム、ランタン、チタン、シリコン、炭素のうちのいず
れかの物質とを混合した物質に特定したもので、特に、
融点が700度以下のリチウム、マグネシウム、アルミ
ニウムのうちのいずれかの物質と、融点が700度を超
えるバリウム、ホウ素、カルシウム、ランタン、チタ
ン、シリコン、炭素のうちのいずれかの物質とを混合し
た場合、蒸発しやすい物質と、比較的融点が高く、蒸発
しにくい物質の2種類以上の融点温度域の異なる物質が
共存することになり、これにより、焼結工程中に効果的
に酸素除去能力が持続するため、酸素濃度の低い多孔質
陽極体を得ることができ、かつ焼結後に改めてマグネシ
ウムによる還元熱処理を行う場合に比べてCV値の減少
も少ないものである。
According to a second aspect of the present invention, the substance coexisting in the sintering of the compact is selected from the group consisting of vanadium, boron, lithium, calcium, barium and lanthanum, and lithium, magnesium and aluminum. Of any of the above, barium, boron, calcium, lanthanum, titanium, silicon, a substance that is specified as a mixture of any of the carbon, in particular,
Any one of lithium, magnesium, and aluminum having a melting point of 700 degrees or less and any one of barium, boron, calcium, lanthanum, titanium, silicon, and carbon having a melting point of more than 700 degrees were mixed. In this case, two or more substances having different melting point temperatures coexist, that is, a substance that easily evaporates and a substance that has a relatively high melting point and is difficult to evaporate, thereby effectively removing oxygen during the sintering process. Is maintained, a porous anode body having a low oxygen concentration can be obtained, and the CV value is less reduced as compared with the case where the reduction heat treatment with magnesium is performed again after sintering.

【0010】次に本発明の具体的な実施の形態と従来例
1、従来例2について説明する。 (実施の形態)タンタル線からなる陽極リードを植設し
た状態でタンタル粉末150mgをφ3.0×4.0mm
の円柱型に加圧成形することにより成形体を形成し、次
にこの成形体を炭素、マグネシウムを共存させて焼結す
ることにより多孔質陽極体を構成した。この場合、成形
体の焼結は温度と真空度を変えて2段階で行っていくも
ので、前段の焼結は温度が1000度、真空度が10-1
Paの真空中において20分間行い、かつ後段の焼結は
温度が1400度の高温、真空度が10-3Paの高真空
中において20分間行うことにより多孔質陽極体を構成
した。その後、この多孔質陽極体を塩酸で洗浄して、余
分の炭素、マグネシウムを除去した。
Next, specific embodiments of the present invention, and Conventional Examples 1 and 2 will be described. (Embodiment) 150 mg of tantalum powder was Φ3.0 × 4.0 mm with an anode lead made of tantalum wire implanted.
To form a compact, and then sintering the compact in the presence of carbon and magnesium to form a porous anode body. In this case, the sintering of the compact is performed in two stages by changing the temperature and the degree of vacuum, and the sintering in the former stage is performed at a temperature of 1000 degrees and a degree of vacuum of 10 -1.
A porous anode body was formed by performing for 20 minutes in a vacuum of Pa for 20 minutes, and performing sintering in a subsequent stage for 20 minutes in a high vacuum having a temperature of 1400 ° C. and a degree of vacuum of 10 −3 Pa. Thereafter, the porous anode body was washed with hydrochloric acid to remove excess carbon and magnesium.

【0011】(従来例1)タンタル線からなる陽極リー
ドを植設した状態でタンタル粉末150mgをφ3.0
×4.0mmの円柱型に加圧成形することにより成形体を
形成し、かつこの成形体を温度が1400度の高温、真
空度が10-3Paの高真空中において20分間焼結する
ことにより多孔質陽極体を構成した。
(Conventional Example 1) 150 mg of tantalum powder was added to φ3.0 with an anode lead made of tantalum wire implanted.
Forming a molded body by pressure molding into a × 4.0 mm cylindrical mold, and sintering the molded body at a high temperature of 1400 ° C. and a high vacuum of 10 −3 Pa for 20 minutes. To form a porous anode body.

【0012】(従来例2)タンタル線からなる陽極リー
ドを植設した状態でタンタル粉末150mgをφ3.0
×4.0mmの円柱型に加圧成形することにより成形体を
形成し、かつこの成形体を温度が1400度の高温、真
空度が10-3Paの高真空中において20分間焼結する
ことにより多孔質陽極体を構成した。この後、多孔質陽
極体を焼結炉から取り出し、改めて真空度が10-1Pa
の真空中で焼結した温度より低い温度の1000度で、
多孔質陽極体をマグネシウムの共存下で20分間熱処理
した。その後、この多孔質陽極体を塩酸で洗浄して、余
分のマグネシウムを除去した。
(Conventional Example 2) 150 mg of tantalum powder was φ3.0 with an anode lead made of tantalum wire implanted.
Forming a molded body by pressure molding into a × 4.0 mm cylindrical mold, and sintering the molded body at a high temperature of 1400 ° C. and a high vacuum of 10 −3 Pa for 20 minutes. To form a porous anode body. Thereafter, the porous anode body was taken out of the sintering furnace, and the degree of vacuum was changed to 10 -1 Pa again.
1000 degrees lower than the temperature sintered in vacuum of
The porous anode body was heat-treated for 20 minutes in the presence of magnesium. Thereafter, the porous anode body was washed with hydrochloric acid to remove excess magnesium.

【0013】(表1)は、本発明の実施の形態と従来例
1,2で得られたそれぞれの多孔質陽極体に0.5wt
%のリン酸水溶液中で50V、2時間の陽極酸化を実施
して、誘電体酸化皮膜を形成した後、この誘電体酸化皮
膜を形成した多孔質陽極体に0.02wt%のリン酸水
溶液中で35Vの電圧を印加して、2分間充電した後の
漏れ電流を測定した結果を示したものである。
Table 1 shows that each of the porous anode bodies obtained in the embodiment of the present invention and Conventional Examples 1 and 2 has 0.5 wt.
A dielectric oxide film is formed by performing anodic oxidation at 50 V for 2 hours in a phosphoric acid aqueous solution of 0.02 wt% in a phosphoric acid aqueous solution of 0.02 wt%. 5 shows the result of measuring the leakage current after charging for 2 minutes by applying a voltage of 35V.

【0014】[0014]

【表1】 (表1)から明らかなように、従来例1,2の多孔質陽
極体に比べて、本発明の実施の形態における多孔質陽極
体は共存物質による酸素除去効果を有するため、多孔質
陽極体における酸素濃度の低減が見られ、その結果、漏
れ電流値が低減することが確認できた。しかも、熱履歴
が少ないため、従来例2に見られるようなCV値の大幅
な減少も見られなかった。
[Table 1] As is clear from (Table 1), the porous anode body according to the embodiment of the present invention has an oxygen removing effect by the coexisting substance, as compared with the porous anode bodies of Conventional Examples 1 and 2, and thus the porous anode body It was confirmed that the oxygen concentration was reduced in the sample, and as a result, the leakage current value was reduced. In addition, since the heat history is small, a significant decrease in the CV value as seen in Conventional Example 2 was not observed.

【0015】この後、本発明の実施の形態と従来例1で
得られた多孔質陽極体の誘電体酸化皮膜表面に半導体
層、カーボン層、銀ペイント層を順次形成してコンデン
サ素子を構成した後、外部引き出し用の陰極リードおよ
び陽極リードを引き出し、その後、樹脂外装を施してタ
ンタル固体電解コンデンサを構成した。
Thereafter, a semiconductor layer, a carbon layer, and a silver paint layer were sequentially formed on the surface of the dielectric oxide film of the porous anode body obtained in the embodiment of the present invention and Conventional Example 1 to form a capacitor element. Thereafter, a cathode lead and an anode lead for external lead-out were pulled out, and thereafter, a resin sheath was applied to form a tantalum solid electrolytic capacitor.

【0016】そして、これらのタンタル固体電解コンデ
ンサについて85℃16V印加の高温負荷試験を100
0時間実施した。この試験結果を図1に示す。この図1
から明らかなように1000時間後においては、従来例
1の多孔質陽極体を使用したタンタル固体電解コンデン
サの漏れ電流の増加に比べて、本発明の実施の形態のよ
うな焼結方法で焼結を行った多孔質陽極体を使用したタ
ンタル固体電解コンデンサは多孔質陽極体の酸素含有量
が低いため、漏れ電流の劣化度合いが少なく、この結果
からも高温負荷寿命試験の信頼性が改善されることが確
認できた。
[0016] These tantalum solid electrolytic capacitors were subjected to a high-temperature load test at 85 ° C and 16 V applied for 100 times.
Performed for 0 hours. FIG. 1 shows the test results. This figure 1
As can be seen from the figure, after 1000 hours, the sintering method according to the embodiment of the present invention is different from the increase in the leakage current of the tantalum solid electrolytic capacitor using the porous anode body of the conventional example 1 in comparison with the conventional method. Tantalum solid electrolytic capacitors using porous anode bodies that have undergone the above-mentioned tests have a low oxygen content in the porous anode bodies, so the degree of deterioration of leakage current is small, and this result also improves the reliability of the high-temperature load life test. That was confirmed.

【0017】なお、上記本発明の実施の形態において
は、タンタル粉末を加圧成形することにより形成した成
形体を焼結して多孔質陽極体を構成する場合、高温高真
空中において炭素、マグネシウムを共存させて焼結を行
ったものについて説明したが、この共存させる物質は、
これに限定されるものではなく、これ以外の例えば、バ
ナジウム、ホウ素、リチウム、カルシウム、バリウム、
ランタンのうちのいずれかの物質、またはリチウム、ア
ルミニウムのうちのいずれかの物質と、バリウム、ホウ
素、カルシウム、ランタン、チタン、シリコンのうちの
いずれかの物質とを混合した物質を用いてもよく、これ
らの物質はタンタルと比べて、酸素親和力の強い物質で
あるため、上記本発明の実施の形態と同様の効果が得ら
れるものである。
In the above-described embodiment of the present invention, when a porous anode body is formed by sintering a compact formed by pressing tantalum powder under pressure, carbon, magnesium Although the sintering was performed in the presence of
It is not limited to this, and other than this, for example, vanadium, boron, lithium, calcium, barium,
Any substance of lanthanum, or a substance obtained by mixing lithium, any of aluminum, and any of barium, boron, calcium, lanthanum, titanium, and silicon may be used. Since these substances have higher oxygen affinity than tantalum, the same effects as those of the above-described embodiment of the present invention can be obtained.

【0018】また、本発明の実施の形態においては、成
形体の焼結を高温高真空中で行ったものについて説明し
たが、不活性ガス中において成形体の焼結を行っても、
上記本発明の実施の形態と同様の効果が得られるもので
ある。
Further, in the embodiment of the present invention, the description has been given of the case where the compact is sintered in a high temperature and high vacuum. However, even if the compact is sintered in an inert gas,
The same effects as those of the embodiment of the present invention can be obtained.

【0019】[0019]

【発明の効果】以上のように本発明の固体電解コンデン
サにおける多孔質陽極体の製造方法は、陽極リードを植
設した状態でタンタル粉末を加圧成形することにより成
形体を形成し、かつこの成形体を高温高真空中または不
活性ガス中においてタンタルと比べて酸素親和力の強い
物質を共存させて焼結することにより多孔質陽極体を構
成し、さらにこの多孔質陽極体を酸で洗浄するようにし
たもので、この製造方法によれば、焼結工程においてタ
ンタル粉末を加圧成形することにより形成された成形体
の表面に吸着している酸素ならびにタンタル粉末中に溶
存している酸素は、酸素親和力の強い共存物質と反応し
て脱酸素が行われるため、従来のように焼結後に改めて
脱酸素熱処理を行う場合に比べて、酸素濃度の低い多孔
質陽極体を得ることができ、かつCV値の減少も少な
い。また、前記多孔質陽極体は酸で洗浄して余分の残渣
を除去するようにしているため、共存物質残渣による誘
電体酸化皮膜中の欠陥部は減少し、これにより、漏れ電
流特性の悪化を防止することができる。この結果、寿命
特性面においても著しい向上が図れるものである。
As described above, the method for producing a porous anode body in a solid electrolytic capacitor according to the present invention comprises forming a compact by pressing and molding tantalum powder with an anode lead being implanted. A porous anode body is formed by sintering the compact in a high temperature and high vacuum or in an inert gas in the presence of a substance having a higher oxygen affinity than tantalum, and then sintering the porous anode body with acid. According to this manufacturing method, the oxygen adsorbed on the surface of the compact formed by pressing the tantalum powder in the sintering step and the oxygen dissolved in the tantalum powder are In addition, since oxygen is reacted with a coexisting substance having a high oxygen affinity to perform deoxidation, a porous anode body having a lower oxygen concentration can be obtained as compared with the conventional case where deoxidation heat treatment is performed again after sintering. It can be, and less reduction of CV value. In addition, since the porous anode body is washed with an acid to remove excess residues, defects in the dielectric oxide film due to coexisting substance residues are reduced, thereby deteriorating leakage current characteristics. Can be prevented. As a result, a remarkable improvement in the life characteristics can be achieved.

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

【図1】本発明の実施の形態と従来例1で得られた多孔
質陽極体を使用したタンタル固体電解コンデンサの高温
負荷試験における漏れ電流結果を比較した特性図
FIG. 1 is a characteristic diagram comparing a leakage current result in a high-temperature load test of a tantalum solid electrolytic capacitor using a porous anode body obtained in an embodiment of the present invention and a conventional porous anode body.

【図2】誘電体酸化皮膜層中の欠陥数と漏れ電流の関係
を示す特性図
FIG. 2 is a characteristic diagram showing a relationship between the number of defects in a dielectric oxide film layer and a leakage current.

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 陽極リードを植設した状態でタンタル粉
末を加圧成形することにより成形体を形成し、かつこの
成形体を高温高真空中または不活性ガス中においてタン
タルと比べて酸素親和力の強い物質を共存させて焼結す
ることにより多孔質陽極体を構成し、さらにこの多孔質
陽極体を酸で洗浄するようにした固体電解コンデンサに
おける多孔質陽極体の製造方法。
1. A compact is formed by pressing a tantalum powder under pressure with an anode lead implanted, and the compact has a higher oxygen affinity than tantalum in a high temperature and high vacuum or in an inert gas. A method for producing a porous anode body in a solid electrolytic capacitor in which a porous anode body is formed by sintering in the presence of a strong substance, and the porous anode body is washed with an acid.
【請求項2】 成形体の焼結において共存させる物質
が、バナジウム、ホウ素、リチウム、カルシウム、バリ
ウム、ランタンのうちのいずれかの物質、またはリチウ
ム、マグネシウム、アルミニウムのうちのいずれかの物
質と、バリウム、ホウ素、カルシウム、ランタン、チタ
ン、シリコン、炭素のうちのいずれかの物質とを混合し
た物質からなる請求項1に記載の固体電解コンデンサに
おける多孔質陽極体の製造方法。
2. A material coexisting in sintering a molded body, the material comprising any one of vanadium, boron, lithium, calcium, barium, and lanthanum; or any one of lithium, magnesium, and aluminum; 2. The method for producing a porous anode body in a solid electrolytic capacitor according to claim 1, wherein the method comprises a material obtained by mixing any one of barium, boron, calcium, lanthanum, titanium, silicon, and carbon.
JP9275477A 1997-10-08 1997-10-08 Manufacture of porous anode in solid electrolytic capacitor Pending JPH11111575A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9275477A JPH11111575A (en) 1997-10-08 1997-10-08 Manufacture of porous anode in solid electrolytic capacitor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9275477A JPH11111575A (en) 1997-10-08 1997-10-08 Manufacture of porous anode in solid electrolytic capacitor

Publications (1)

Publication Number Publication Date
JPH11111575A true JPH11111575A (en) 1999-04-23

Family

ID=17556082

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9275477A Pending JPH11111575A (en) 1997-10-08 1997-10-08 Manufacture of porous anode in solid electrolytic capacitor

Country Status (1)

Country Link
JP (1) JPH11111575A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008235897A (en) * 2007-03-20 2008-10-02 Avx Corp Anode for use in electrolytic capacitor
US7594937B2 (en) 2004-11-29 2009-09-29 Showa Denko K.K. Porous anode body for solid electrolytic capacitor, production method thereof and solid electrolytic capacitor
WO2024203050A1 (en) * 2023-03-24 2024-10-03 パナソニックIpマネジメント株式会社 Electrolytic capacitor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7594937B2 (en) 2004-11-29 2009-09-29 Showa Denko K.K. Porous anode body for solid electrolytic capacitor, production method thereof and solid electrolytic capacitor
JP2008235897A (en) * 2007-03-20 2008-10-02 Avx Corp Anode for use in electrolytic capacitor
WO2024203050A1 (en) * 2023-03-24 2024-10-03 パナソニックIpマネジメント株式会社 Electrolytic capacitor

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