JP4182832B2

JP4182832B2 - Superconducting plate connection method and connection part thereof

Info

Publication number: JP4182832B2
Application number: JP2003207672A
Authority: JP
Inventors: 昌也小西
Original assignee: Sumitomo Electric Industries Ltd
Current assignee: Sumitomo Electric Industries Ltd
Priority date: 2003-08-18
Filing date: 2003-08-18
Publication date: 2008-11-19
Anticipated expiration: 2023-08-18
Also published as: JP2005063695A

Description

【０００１】
【発明の属する技術分野】
本発明は、超電導ケーブル、超電導マグネット、超電導発電装置等の電力機器類や医療用機器、超電導電流リード等に用いる酸化物超電導板状体、中でも薄膜超電導板状体の接続方法及びその接続部に関する。
【０００２】
【従来の技術】
従来の超電導材料には、金属線材を用いた低温超電導材料と、酸化物を用いた高温超電導材料が存在する。本発明は高温超電導材料を用いた超電導材料のうち、基材上に超電導薄膜を形成してなる超電導薄膜板状体に関する。ここでいう酸化物超電導板状体とは、長尺でフレキシブルな金属などの基板上に酸化物超電導膜を堆積した超電導薄膜線材、単結晶基板上に酸化物超電導膜を堆積したものなどを指す。基板と酸化物超電導薄膜との間には、必要に応じて中間層が設けられることもある。
【０００３】
薄膜超電導板状体は、平板形状であることと、金属材料のように機械加工性に優れたものでもないため、超電導板状体同士の接続においてウェルディングジョイントのような簡単な接続が出来ず、種々工夫がなされてきた。
超電導薄膜同士を接続する例として、真空容器内にて酸化物超電導板状体同士を当接し、その当接部にあてて不活性ガスと酸化物超電導体微粉を噴出し、該超微粉を焼結させることにより、酸化物超電導板状体を接続する手段の開示がある（特許文献１参照）。しかし、このような酸化物超電導焼結体の超電導臨界電流密度（Ｊｃ）は、接続される超電導薄膜のＪｃに比べて非常に小さいため焼結体部分の厚み及び薄膜との接触面積を大きくする必要がある。また、もし焼結体部分で超電導臨界電流密度を超えた電流が流れた場合には、通常の金属よりも大きな電気抵抗を発生してしまう。
【０００４】
別の接続技術の開示には、図７で示されるものがある（特許文献２参照）。この図７は同一出願人からさらなる改善発明が開示されている（特許文献３参照）。従って、図７、図８，図９は後者の開示内容を参照したものである。
図７において、基材１０１上に、中間層１０２を形成し、この中間層１０２上に酸化物超電導層１０３を形成し、さらに酸化物超電導層１０３上に安定化銀層１０４を形成した酸化物超電導板状体１０５を接続する手段として、安定化銀層１０４同士を向かい合わせ、その間に半田１０６を用いて接続する方法である。
【０００５】
図８は酸化物超電導板状体を突き合わせて接続した例である。この方法は、基材１１１と中間層１１２の上に酸化物超電導層１１３があり、このような超電導板状体１１５を互いに突き合わせ、この突き合わせ部に低融点酸化物超電導層１１７がついた基材１１６を有する接続用超電導テープ１１８をのせ、該接続用超電導テープ１１８を加熱し、低融点酸化物超電導層１１７を溶融させて接続する。その上に薄膜形成手段で安定化銀層１１４を覆うことで接続している。
さらなる改善手段が図９である。この方法は、酸化物超電導板状体１３５の突き合わせ部付近の酸化物超電導層１３３を一部削り、この部分に貴金属からなる接続層１３１を形成する。その上に接続用酸化物超電導層１３２を設け、最後に貴金属等で表面保護膜１３４を設けるものである。この例では、通常、基板同士を高温で圧接する必要があるため、高温によって周辺の超電導薄膜の特性が低下することが懸念される。また、圧接部を平坦にしなければ、その部分で接続用超電導体に結晶粒界が発生してＪｃを下げる要因となるため、高度な技術で平坦な圧接を行う必要がある。
【０００６】
【特許文献１】
特許第２６８８９２３号公報、（第３欄２０行−第４欄１５行）
【特許文献２】
特開２０００−１３３０６７号公報、（００１１，００１９−００２２）
【特許文献３】
特開２００１−３１９７５０号公報、（０００８−０００９）
【０００７】
【発明が解決しようとする課題】
酸化物超電導板状体同士を接続する場合に、常電導体を介して半田等で接続すれば、電気抵抗が発生するため、損失が増し、熱が発生する。また、酸化物超電導体を介して接続した場合であっても、超電導特性が不十分であれば良好な接触は得られない。前記したような酸化物超電導板状体には、ＲＥ１２３（Ｙ，Ｎｄ、Ｓｍ等の希土類元素）系材料が良く用いられる。このようなＲＥ１２３系超電導材料は、結晶方位が揃った単結晶状態ではじめて良好な超電導特性を得ることが出来るのである。
【０００８】
【課題を解決するための手段】
本発明は、以上のような問題を解決する手段である。その第１の方法は、基材上に超電導薄膜が形成されてなる超電導板状体の接続方法であって、接続対象である２つの超電導板状体の超電導薄膜表面の一部が互いに接触するように組み合わせ、かつ当該接触した双方の超電導薄膜の結晶方位がほぼ一致するように位置調整した後、該超電導薄膜が接触している部分に続く薄膜面に、前記超電導薄膜と同種の超電導薄膜を堆積させることを特徴とする。このとき、堆積される超電導薄膜の結晶方位が、下地の超電導薄膜の結晶方位と一致して堆積されるよう（エピタキシャル成長するよう）堆積方法・条件を選ぶ。堆積される面に対向して接触している超電導薄膜に対しては、その側面に超電導薄膜（堆積される膜）が連続して堆積される。このようにすれば、超電導薄膜の接続境界での抵抗は減少する。すなわち、接続される双方の超電導薄膜の結晶方位が一致しているため、接続部分に続く薄膜面に超電導薄膜を堆積することにより、接続境界面を含めて超電導薄膜が単結晶化する。双方の結晶方位が一致していなければ、接続される薄膜と堆積される薄膜との界面、又は堆積される薄膜中に傾角粒界が発生するが、双方の結晶方位のずれが小さい場合には、この傾角粒界で発生するＪｃの低下は、無視し得る程度に小さい。
前記接続対象である超電導板状体のいずれか一方もしくは双方の超電導薄膜の互いに接触する部分の一部を、基材面に対して斜めに加工する工程をさらに備えることより、対向する薄膜の側面の面積が実質的に増大し、境界面の単結晶化がよりスムーズに進行するため好ましい。また、前記堆積された超電導膜の表面に、さらに導電性の保護膜を形成するとより好ましく、さらに前記保護膜をさらに絶縁被覆で覆うことにより、耐久性を向上でき好ましい。
【０００９】
本発明の第２の方法は、基材上に超電導薄膜が形成されてなる超電導板状体の接続方法であって、接続対象である２つの超電導板状体のそれぞれの端部を、接続用基板の上に、前記それぞれの超電導板状体の超電導薄膜の面が該接続用基板の表面に接するように置き、該超電導薄膜の結晶方位がほぼ一致し、かつ該超電導板状体のそれぞれの端部が間隙を有するように該接続用基板上に固定した後、該接続用基板の該間隙部分に、前記超電導薄膜と同種の超電導薄膜を堆積させることを特徴とする超電導板状体の接続方法である。この方法でも、超電導薄膜を新たに堆積する超電導薄膜で単結晶状に接続できるため、接続部分での大きな抵抗を発生しない。さらに、この方法の利点は、接続される双方の超電導薄膜の面（基板に対しての）が、同じ方向を向くため、機器への応用に適していることである。
前記接続対象である超電導板状体のいずれか一方もしくは双方の超電導薄膜の一部を、基材面に対して斜めに加工する工程をさらに備えることで、超電導薄膜の単結晶化が助長でき好ましい。また、前記堆積された超電導薄膜の表面に、さらに導電性の保護膜を形成するのがよく、前記保護膜の表面をさらに絶縁被覆で覆い、接続される超電導板状体の双方の基材間の間隙を埋め、その後前記基材を除去することで、接続部分の肥大化を防ぐことができより好ましい。
【００１０】
本発明の第３の方法は、基材上に超電導薄膜が形成されてなる超電導板状体の接続方法であって該超電導薄膜の一部に不良部を有する第１の超電導板状体に、別に用意した基材上に超電導薄膜が形成されてなる第２の超電導板状体を、超電導薄膜面が前記不良部を覆って互いに接触するように組み合わせ、該超電導薄膜が接触する部分に続く薄膜面に、前記超電導薄膜と同種の超電導薄膜を堆積させることを特徴とする超電導板状体の接続方法である。この方法は、第１の超電導板状体の不良部に電流のバイパスとして第２の超電導板状体を接続することで、不良部による全体の特性低下を抑制する方法である。本発明の第１の方法及び第２の方法からの応用として、実用上有効な方法である。
従って、接触する双方の超電導薄膜の結晶方位がほぼ一致するように位置調整した後、該超電導薄膜が接触する部分に続く薄膜面に、前記超電導薄膜と同種の超電導薄膜を堆積させるようにするのが好ましい。
【００１１】
本発明の第４の発明は、前記第１の発明により形成される接続部である。具体的には、基材上に超電導薄膜が形成された第１の超電導板状体と、該第１の超電導板状体の超電導薄膜の表面に、超電導薄膜同士が接し、かつ双方の超電導薄膜の結晶方位がほぼ一致するように配置された第２の超電導板状体と、該超電導薄膜が接触する部分に続く薄膜面に、前記超電導薄膜と同種の超電導薄膜が堆積されていることを特徴とする超電導板状体の接続部である。
本発明の第５の発明は、前記第２の発明によって形成される接続部である。具体的には、基材上に超電導膜が形成された第１の超電導板状体の端部と、別に用意された基材上に超電導薄膜が形成された第２の超電導板状体の端部が、間隙を空けて配置されており、当該間隙には前記第１の超電導板状体の超電導薄膜と前記第２の超電導板状体の超電導薄膜を接続するように超電導薄膜が形成されており、当該超電導薄膜の結晶方位は、前記第１の超電導板状体の超電導薄膜の結晶方位と前記第２の超電導板状体の結晶方位のいずれともほぼ一致していることを特徴とする超電導板状体の接続部である。
本発明の第６の発明は、前記第３の発明によって形成される接続部である。具体的には、基材上に超電導薄膜が形成されてなる超電導板状体であって該超電導薄膜の一部に不良部を有する第１の超電導板状体の超電導薄膜表面に、別に用意された基材上に超電導薄膜が形成されてなる第２の超電導板状体の、超電導薄膜面が前記不良部を覆って接触するように組み合わされ、該超電導薄膜が接触する部分に続く薄膜面に、該超電導薄膜と同種の超電導薄膜が堆積されていることを特徴とする超電導板状体の接続部である。
【００１２】
【発明の実施の形態】
本発明における第１の方法を、模式図をもって説明する。図１（ａ）のように基材１、１′に超電導薄膜２、２′が形成された超電導板状体３、３′を超電導薄膜２、２′同士の一部が互いに接触するように組み合わせ、重ねる。このとき、超電導薄膜２、２′同士の結晶方位を合わせる。結晶方位については、超電導板状体を作製した時点で既知である。すなわち、超電導板状体が基板である場合には、該基板の基材に単結晶が用いられるため、その表面に堆積する超電導薄膜の結晶方位をコントロールできる。また、超電導板状体が線材である場合には、基材となる金属テープの結晶方位をコントロールできるため、そこに堆積する超電導薄膜も結晶方位をコントロールできる。もしくは、結晶方位をコントロールできていない金属テープ表面に結晶方位をコントロールした中間層を設けることにより、その上に堆積する超電導薄膜の結晶方位をコントロールできる。
一般に超電導板状体３は基材１と超電導薄膜２の間に中間層が存在するが、ここでは省略している。
図１（ａ）のように重ね合わせた部分に続く薄膜面の片方若しくは両方に、図１（ｂ）のように接続用超電導薄膜４を堆積させる。この堆積により、接続用超電導薄膜４は、超電導薄膜２に対してエピタキシャルに成長し、重なり合う超電導薄膜２′の側面部分に連続するように堆積し、接続用超電導薄膜４と重ね合わされた超電導薄膜２，２′全体が単結晶化することにより、接続部における超電導性を確保する。
このとき、図２のように重なり合う超電導薄膜２′の一部を基材面に対して斜めに加工すると、この斜め加工面５に沿って接続用超電導薄膜４がエピタキシャルに成長し、重なり合う超電導薄膜２，２′を単結晶化させる。
【００１３】
本発明の第１の方法を確実にするには、図３に示すように、重ね合わせた超電導板状体３，３′の上下両面に接続用超電導薄膜４，４′を堆積し、接続用超電導薄膜４，４′の露出面に導電性の保護膜６，６′を形成するのが好ましい。形成された導電性の保護膜６、６′を絶縁被覆７、７′を用いて覆うと良い。なお図３には、図２で示した斜め加工面を省略してあるが、超電導薄膜２，２′に斜め加工面を施す方が好ましい。
また、本発明の第１の方法では、接続する超電導板状体の基材同士の接合がないため、接続する双方の基材の種類が異なっていても、寸法の違いがあっても接続可能であり、薄膜線材と薄膜基板を接続する場合にも応用できる手段である。
【００１４】
なお、ここで用いる超電導体は、超電導薄膜にＲＥ１２３系材料を、中間層にはイットリア安定化ジルコニア（ＹＳＺ）、ＣｅＯ２等を用い、基材にはＮｉ、Ｎｉ−Ｆｅ合金（商品名：ハステロイなど）、Ｎｉ複合材等を用いるのが良い。また、接続方法としては、超電導薄膜を堆積する手段として、パルスレーザー蒸着法（ＰＬＤ）、高周波（ＲＦ）スパッタリング、熱共蒸着等の物理蒸着法、化学気相法（ＭＯＣＶＤなど）、液相エピタキシー法（ＬＰＥ）、有機金属析出法（ＭＯＤ）等の化学析出法を用いるとよい。また、保護膜としては貴金属をスパッタリング法にて作製するのが好ましい。絶縁被覆の材料は、樹脂もしくはセラミック接着剤を利用するのが好ましい。
本発明における第４の発明は、模式図で示すと、図１ａ、図２、図３が該当する。
【００１５】
本発明の第２の方法は、図４及び図５の模式図をもって説明する。図４（ａ）のように、台座となる基板１１上にある程度の間隔を開けて接続される超電導板状体３，３′を置き、固定する。この固定は、機械的であっても、科学的な手段であっても構わない。超電導板状体３，３′は基材１，１′と超電導薄膜２，２′からなる。基材と超電導薄膜間の中間層は省略してある。そして、図４（ｂ）のように、基板１１上の間隔部分に接続用超電導薄膜１２を堆積させる。このようにすると、基板１１上に堆積した接続用超電導薄膜１２は、超電導板状体３，３′の超電導薄膜２，２′と結晶方位をあわせて堆積されるので、単一結晶状になって接続する。
図４では省略するが、基板１１上に置かれた超電導板状体３，３′の超電導薄膜２，２′の一方若しくは双方の一部を基材面に対して斜めに加工しておくと、堆積する接続用超電導薄膜１２がエピタキシャルに成長し、超電導薄膜２，２′と結晶方位を合わせた状態になりやすい。
【００１６】
本発明の第２の方法をより確実にするには、図５（ａ）に示すようにすればよい。すなわち、図４（ｂ）で作製された接続用超電導薄膜１２の堆積物の表面に、保護膜１３を形成すると、超電導薄膜が外部から保護された状態になる。さらにその上に絶縁被覆１４で覆い、接続される超電導板状体の基材間を埋めると、保護が確実になる。なお、絶縁被覆１４は、超電導板状体３，３′と同じ高さに調整すれば、接続部の突出を避けられる。
さらには、図５（ｂ）のように、固定されていた基板１１を除去すれば、接続部分が超電導板状体３，３′と同一の厚みとすることができ、接続部の違和感を減少できる。
なお、ここで用いる超電導板状体は、第１の方法で用いたものと同じ内容で構わないが、台座とする基板には、堆積させる接続用超電導薄膜がエピタキシャルに成長することを助長するものが好ましい。例えば、ＭｇＯ、ＬａＡｌＯ_３、ＳｒＴｉＯ_３（ＳＴＯ）などの単結晶基板でもよいし、サファイア上に配向性中間層が形成されたものでも良い。また、基板用の金属の上に配向した中間層を設けたものでも構わない。さらには、超電導薄膜をその上に積層したものも用いることが出来る。
本発明における第５の発明は、模式図で示すと図４ｂ、図５ａ、図５ｂが該当する。
【００１７】
本発明の第３の方法は、図６の模式図で説明する。この方法は、超電導板状体の不良部を修復する方法であり、前記２つの接続方法とは若干意味を異にするが、超電導板状体を使用する上で、接続するものである。図６のように、超電導薄膜２の一部に不良部１５を有する第１の超電導板状体３を置き、その上に別途準備した良好な第２の超電導板状体１８を、基材１６を上に、超電導薄膜１７を下にして、前記不良部１５を互いに接触するように組み合わせる。このときも超電導薄膜２，１７の結晶方位がほぼ一致するように位置調整しておくことが好ましい。置かれた超電導板状体１８の端部に接続用超電導薄膜１９，１９′を堆積することにより、超電導板状体３と超電導板状体１８の超電導薄膜２，１７は、接続用超電導薄膜１９，１９′と一体化し、単結晶化する。
ここで用いる修理用の超電導板状体１８は、修理する超電導板状体３と同じものが好ましいが、超電導薄膜同士が類似するものであれば、別の種類の超電導板状体を用いても構わない。
本発明の第６の発明は、模式図で示すと図６が該当する。
以上記載したように、本発明は超電導薄膜の接続形態に合わせた接続方法を示す。いずれも、多種多様の超電導薄膜を有する超電導板状体に関して応用できる手段である。
【００１８】
【実施例】
以下に本発明の実施例を示すが、本発明は応用範囲が広いため、実施例に限定されるものではない。
以下の実施例に於いて、超電導板状体には以下の構成である超電導線材と超電導基板を用いている。
超電導線材には、基材にＮｉ−Ｆｅ合金（商品名；ハステロイ）、中間層にイットリア安定化ジルコニア（ＹＳＺ）、超電導薄膜にＨｏＢａ_２Ｃｕ_３Ｏ_７−ｘ（ＨｏＢＣＯ）を用いた。線材の幅１ｃｍ、長さ３０ｃｍ、厚み０．１ｍｍであり、臨界電流値（Ｉｃ）が約３０Ａのものである。また、ＨｏＢＣＯ膜は厚さ約１μｍである。
超電導基板には、基材にＬａＡｌＯ_３単結晶を、その上に約１μｍのＨｏＢＣＯを堆積したものを用いた。サイズは直径５０ｍｍ厚み０．５ｍｍ、臨界電流密度（Ｊｃ）が約３×１０^６Ａ／ｃｍである。
【００１９】
（実施例１）図１（ａ）のように、超電導板状体３，３′として超電導線材２本を用意し、超電導薄膜２，２′が端部５ｃｍ重なるようにして薄膜堆積用ホルダ（図示せず）に固定した。この状態で高周波（ＲＦ）スパッタリング装置にセットし、図１（ｂ）のように、接続用超電導薄膜４としてＨｏＢＣＯ膜を約１．５μｍ堆積した。この状態のまま直流（ＤＣ）スパッタリング装置に薄膜堆積用ホルダを移し、図３のように接続用超電導薄膜４上に導電性の保護膜６として銀薄膜を形成した。その後、銀薄膜を覆って、絶縁被覆７に相当する部分を樹脂で固定してから、薄膜堆積用ホルダから外した。接続された超電導板状体の超電導電流値（Ｉｃ）は３０Ａあり、接続が完全なものであることが確認できた。
【００２０】
（実施例２）図１（ａ）のように、一方の超電導板状体３に超電導薄膜基板を用い、他方の超電導板状体３′に超電導線材を用い、薄膜部分を１ｃｍ重なるように置き、薄膜堆積用ホルダで固定した。これを実施例１と同様の操作により、図１（ｂ）のように接続用超電導薄膜４としてＨｏＢＣＯを１．５μｍ堆積し、さらに図３のように、その上にＤＣスパッタリングで導電性の保護膜６として銀薄膜を堆積した。その後薄膜堆積用ホルダから外し、接続部を含む導電性を計測したところ、Ｉｃが３０Ａであることを確認した。
【００２１】
（実施例３）図４（ａ）に示す基板１１として、長さ５ｃｍにした超電導線材を用い、この上に、超電導板状体３，３′として２つの超電導線材を、端部の間隙３ｍｍあけ基材を上にして置いた。これらの幅方向端部をスポット溶接を用いて固定し、３ｍｍの間隙部分にパルスレーザー蒸着法（ＰＬＤ法）により、図４（ｂ）に示す接続用超電導薄膜１２として、ＨｏＢＣＯを１．５μｍ堆積した。その後、図５のように、ＤＣスパッタリング法で接続用超電導膜１２の上に、保護膜１３として銀薄膜を形成した。この状態で接続部を含む超電導板状体の導電性を調べたところ、Ｉｃが２７Ａであり、接続が正常であることを示した。
【００２２】
（実施例４）図４（ａ）に示す基板１１として、ＭｇＯの単結晶基板（１０ｍｍ角）を用意した。この上に超電導板状体３，３′として、２つの超電導線材を、端部の間隙３ｍｍあけ基材を上にして置いた。この状態で図４（ｂ）に示すように、接続用超電導薄膜１２としてＨｏＢＣＯ膜を、間隙部分にＰＬＤ法を用いて、１．５μｍ堆積した。その後、図５（ａ）のように保護膜１３として、銀薄膜をＤＣスパッタリング法で形成した後、絶縁被覆１４としてセラミック系接着剤を段差部分を埋め込むように充填し、固定した。この接続部を有する超電導板状体のＩｃは３０Ａであったので、正常な接続が出来た。
【００２３】
（実施例５）図４（ａ）に示す基板１１として、銀単結晶基板（１０ｍｍ角）を用意した。この上に超電導板状体３，３′として、２つの超電導線材を、端部の間隙３ｍｍあけ基材を上にして置き、ＰＦスパッタリング法により、図４（ｂ）の接続用超電導薄膜１２として、ＨｏＢＣＯを間隙部分に１．５μｍ堆積した。その後図５（ａ）のようにＨｏＢＣＯ薄膜の上に導電性の保護膜１３として銀薄膜をＤＣスパッタリング法で形成し、その上に絶縁被覆１４としてセラミック系接着剤を用い、覆った。
出来た接続部に、希硝酸を用いてエッチングし、銀の単結晶基板を除去した。ここで出来た接続部は、超電導板状体とほぼ同じ厚みと幅になり、接続部の膨れによる障害を除去できた。また電気伝導性もＩｃが２６Ａを示し、問題はない。
【００２４】
（実施例６）超電導板状体３である超電導線材の、中央付近の超電導薄膜に針の先端で傷を付けた。この線材のＩｃは通常３０Ａであるところ、前記傷に起因する不良部により１Ａ以下を示し、傷不良となった。該超電導線材を、図６のように、前記の不良部１５を中心にして超電導薄膜２を上にして置き、その上に長さ５ｃｍに切った超電導板状体１８である超電導線材を、基材を上にして双方の超電導膜が接触するように重ね合わせた。超電導板状体３及び１８をスポット溶接により固定した後、超電導板状体１８の両端部をＰＬＤ法を用いて超電導薄膜１９，１９′、具体的にはＨｏＢＣＯ膜を堆積した。その後、ＨｏＢＣＯ膜の上にＤＣスパッタリング法で銀薄膜を形成し、導電性の保護膜とした。以上のように補修された超電導板状体は、Ｉｃが２８Ａまで快復した。
【００２５】
【発明の効果】
本発明によれば、接続しにくい酸化膜を主体とする超電導板状体を接続後の超電導電流値を大きく減少させず、また、接続による大きな断面増加もなく接続でき、また、作業性も良いものとなる。
【図面の簡単な説明】
【図１】本発明の第１の方法を示す模式図である。（ａ）は超電導板状体を重ね合わせた図であり、（ｂ）は接続用超電導膜で接続した状態である。
【図２】本発明の第１の方法を応用した例の模式図である。
【図３】本発明の第１の方法による実施態様を示す例の模式図である。
【図４】本発明の第２の方法を示す模式図である。（ａ）は基板上に接続対象物を載置した図であり、（ｂ）は接続用超電導膜で接続した状態である。
【図５】本発明の第２の方法をより確実に行った例の模式図である。（ａ）は接続用超電導薄膜上に保護膜を堆積した状態であり、（ｂ）はさらに基板を取り去った状態である。
【図６】本発明の第３の方法を示す模式図である。
【図７】先行技術に示された接続模式図である。
【図８】先行技術に示された接続模式図の別の例である。
【図９】先行技術に示された、さらに別の接続模式図の例である。
【符号の説明】
１，１′．基材
２，２′．超電導薄膜
３．３′．超電導板状体
４．４′．接続用超電導薄膜
５．斜め加工面
６，６′．導電性の保護膜
７，７′．樹脂若しくはセラミック接着剤
１１．基板
１２．接続用超電導薄膜
１３．導電性の保護膜
１４．絶縁被覆
１５．不良部
１６．基材
１７．超電導薄膜
１８．超電導板状体
１９、１９′．接続用超電導薄膜
１０１．基材
１０２．中間層
１０３．酸化物超電導層
１０４．安定化銀層
１０５．酸化物超電導板状体
１０６．半田
１１１．基材
１１２．中間層
１１３．酸化物超電導層
１１４．安定化銀層
１１５．超電導板状体
１１６．基材
１１７．低融点酸化物超導電層
１１８．接続用超電導テープ
１２１．基材
１３１．接続層
１３２．接続用酸化物超電導層
１３３．酸化物超電導層
１３４．表面保護膜
１３５．酸化物超電導板状体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a superconducting cable, a superconducting magnet, a superconducting power generator and other power equipment, medical equipment, a superconducting current lead for use in an oxide superconducting plate, particularly a thin-film superconducting plate-like connection method and a connecting portion thereof. .
[0002]
[Prior art]
Conventional superconducting materials include low-temperature superconducting materials using metal wires and high-temperature superconducting materials using oxides. The present invention relates to a superconducting thin film plate formed by forming a superconducting thin film on a base material among superconducting materials using a high temperature superconducting material. As used herein, the oxide superconducting plate refers to a superconducting thin-film wire in which an oxide superconducting film is deposited on a long and flexible metal substrate, or an oxide superconducting film deposited on a single crystal substrate. . An intermediate layer may be provided as needed between the substrate and the oxide superconducting thin film.
[0003]
The thin-film superconducting plate is flat and does not have excellent machinability like a metal material. Therefore, a simple connection like a welding joint cannot be made between superconducting plates. Various ideas have been made.
As an example of connecting superconducting thin films, oxide superconducting plates are brought into contact with each other in a vacuum vessel, and an inert gas and oxide superconducting fine powder are ejected to the contacted portion, and the superfine powder is baked. There is a disclosure of means for connecting oxide superconducting plate-like bodies by bonding (see Patent Document 1). However, since the superconducting critical current density (Jc) of such an oxide superconducting sintered body is very small compared to Jc of the superconducting thin film to be connected, the thickness of the sintered part and the contact area with the thin film are increased. There is a need. Further, if a current exceeding the superconducting critical current density flows in the sintered body portion, an electric resistance larger than that of a normal metal is generated.
[0004]
Another connection technique is disclosed in FIG. 7 (see Patent Document 2). In FIG. 7, a further improved invention is disclosed by the same applicant (see Patent Document 3). Accordingly, FIGS. 7, 8, and 9 refer to the latter disclosure.
In FIG. 7, an intermediate layer 102 is formed on a substrate 101, an oxide superconducting layer 103 is formed on the intermediate layer 102, and a stabilized silver layer 104 is formed on the oxide superconducting layer 103. As means for connecting the superconducting plate 105, the stabilized silver layers 104 face each other and are connected using a solder 106 therebetween.
[0005]
FIG. 8 shows an example in which oxide superconducting plates are connected to each other. In this method, a substrate having an oxide superconducting layer 113 on a substrate 111 and an intermediate layer 112, such superconducting plate-like bodies 115 are butted against each other, and a low melting point oxide superconducting layer 117 is attached to the butted portion. A connecting superconducting tape 118 having 116 is placed, the connecting superconducting tape 118 is heated, and the low melting point oxide superconducting layer 117 is melted and connected. It is connected by covering the stabilized silver layer 114 with thin film forming means thereon.
FIG. 9 shows a further improvement means. In this method, a part of the oxide superconducting layer 133 in the vicinity of the butt portion of the oxide superconducting plate-like body 135 is partly cut, and a connection layer 131 made of a noble metal is formed in this part. A connecting oxide superconducting layer 132 is provided thereon, and finally a surface protective film 134 is provided with a noble metal or the like. In this example, since it is usually necessary to press the substrates together at a high temperature, there is a concern that the characteristics of the surrounding superconducting thin film may deteriorate due to the high temperature. Further, if the pressure contact portion is not flattened, a crystal grain boundary is generated in the connecting superconductor at that portion, which causes a decrease in Jc. Therefore, it is necessary to perform flat pressure contact with advanced technology.
[0006]
[Patent Document 1]
Japanese Patent No. 2688923, (third column 20th line-fourth column 15th line)
[Patent Document 2]
JP 2000-133067 A, (0011, 0019-0022)
[Patent Document 3]
JP 2001-319750 A, (0008-0009)
[0007]
[Problems to be solved by the invention]
When the oxide superconducting plates are connected to each other with solder or the like via a normal conductor, an electrical resistance is generated, so that the loss is increased and heat is generated. Moreover, even when connected via an oxide superconductor, good contact cannot be obtained if the superconducting properties are insufficient. RE123 (rare earth elements such as Y, Nd, and Sm) -based materials are often used for the oxide superconducting plate as described above. Such an RE123-based superconducting material can obtain good superconducting properties only in a single crystal state in which crystal orientations are aligned.
[0008]
[Means for Solving the Problems]
The present invention is a means for solving the above problems. The first method is a method of connecting a superconducting plate-like body in which a superconducting thin film is formed on a substrate, and a part of the surface of the superconducting thin film of the two superconducting plate-like bodies to be connected contacts each other. And adjusting the position so that the crystal orientations of both of the superconducting thin films in contact with each other are substantially coincident with each other, and then applying a superconducting thin film of the same type as the superconducting thin film on the thin film surface following the portion where the superconducting thin film is in contact It is characterized by depositing. At this time, the deposition method and conditions are selected so that the crystal orientation of the superconducting thin film to be deposited coincides with the crystal orientation of the underlying superconducting thin film (epitaxial growth). For a superconducting thin film in contact with the surface to be deposited, the superconducting thin film (deposited film) is continuously deposited on the side surface. In this way, the resistance at the connection boundary of the superconducting thin film is reduced. That is, since the crystal orientations of both of the superconducting thin films to be connected coincide with each other, the superconducting thin film is formed into a single crystal including the connection boundary surface by depositing the superconducting thin film on the thin film surface following the connecting portion. If both crystal orientations do not match, an inclined grain boundary is generated at the interface between the thin film to be connected and the thin film to be deposited, or in the deposited thin film. The decrease in Jc generated at this tilt grain boundary is so small that it can be ignored.
The side surface of the opposing thin film is further provided with a step of processing a part of a part of the superconducting thin film that is the connection target of the superconducting thin film in contact with each other obliquely with respect to the substrate surface. Is substantially increased, and single crystallization of the boundary surface proceeds more smoothly. Further, it is more preferable to further form a conductive protective film on the surface of the deposited superconducting film, and it is preferable that the protective film is further covered with an insulating coating to improve durability.
[0009]
The second method of the present invention is a method of connecting a superconducting plate-like body in which a superconducting thin film is formed on a substrate, and each end of two superconducting plate-like bodies to be connected is connected. On the substrate, the surface of the superconducting thin film of each superconducting plate is placed in contact with the surface of the connecting substrate, the crystal orientation of the superconducting thin film is substantially coincident, and each of the superconducting plate is A superconducting plate-like body connection characterized in that a superconducting thin film of the same type as the superconducting thin film is deposited on the gap portion of the connecting substrate after being fixed on the connecting substrate so that the end has a gap. Is the method. Even in this method, since the superconducting thin film on which the superconducting thin film is newly deposited can be connected in a single crystal form, a large resistance is not generated at the connecting portion. Furthermore, the advantage of this method is that it is suitable for application to equipment because the faces of both superconducting thin films to be connected (to the substrate) face the same direction.
It is preferable that a single crystallization of the superconducting thin film can be promoted by further comprising a step of processing a part of one or both of the superconducting thin plates to be connected obliquely with respect to the base material surface. . Further, it is preferable to further form a conductive protective film on the surface of the deposited superconducting thin film. The surface of the protective film is further covered with an insulating coating, and between the substrates of both of the superconducting plates to be connected. It is more preferable to fill the gaps and then remove the base material, which can prevent the connection portion from becoming enlarged.
[0010]
A third method of the present invention is a method of connecting a superconducting plate formed by forming a superconducting thin film on a substrate, and the first superconducting plate having a defective portion in a part of the superconducting thin film, A second superconducting plate-like body in which a superconducting thin film is formed on a separately prepared base material is combined so that the superconducting thin film surface covers the defective portion and comes into contact with each other, and the thin film continues to the portion where the superconducting thin film contacts A superconducting plate-like connection method characterized in that a superconducting thin film of the same type as the superconducting thin film is deposited on the surface. In this method, the second superconducting plate-like body is connected as a current bypass to the defective portion of the first superconducting plate-like body, thereby suppressing the entire characteristic deterioration due to the defective portion. It is a practically effective method as an application from the first method and the second method of the present invention.
Therefore, after adjusting the position so that the crystal orientations of both of the superconducting thin films that are in contact with each other substantially coincide with each other, a superconducting thin film of the same type as the superconducting thin film is deposited on the thin film surface following the portion in contact with the superconducting thin film. Is preferred.
[0011]
A fourth invention of the present invention is a connection portion formed by the first invention. Specifically, the first superconducting plate having a superconducting thin film formed on a substrate, the superconducting thin film in contact with the surface of the superconducting thin film of the first superconducting plate, and both superconducting thin films A superconducting thin film of the same type as the superconducting thin film is deposited on the second superconducting plate-like body arranged so that the crystal orientations thereof substantially coincide with each other, and on the thin film surface following the portion in contact with the superconducting thin film It is a connection part of the superconducting plate-like body.
A fifth invention of the present invention is a connection portion formed by the second invention. Specifically, the end of the first superconducting plate having a superconducting film formed on the substrate and the end of the second superconducting plate having a superconducting thin film formed on a separately prepared substrate. And a superconducting thin film is formed in the gap to connect the superconducting thin film of the first superconducting plate and the superconducting thin film of the second superconducting plate. And the crystal orientation of the superconducting thin film substantially coincides with the crystal orientation of the superconducting thin film of the first superconducting plate and the crystal orientation of the second superconducting plate. It is a connection part of a plate-shaped body.
A sixth invention of the present invention is a connection portion formed by the third invention. Specifically, a superconducting plate-like body in which a superconducting thin film is formed on a substrate, which is separately prepared on the surface of the superconducting thin film of the first superconducting plate-like body having a defective portion in a part of the superconducting thin film. The second superconducting plate-like body formed by forming the superconducting thin film on the substrate is combined so that the superconducting thin film surface covers and touches the defective portion, and the thin film surface following the portion in contact with the superconducting thin film A superconducting plate-like connecting portion in which a superconducting thin film of the same type as the superconducting thin film is deposited.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The first method in the present invention will be described with reference to schematic views. As shown in FIG. 1 (a), the superconducting plates 3, 3 'having the superconducting thin films 2, 2' formed on the substrates 1, 1 'are arranged such that a part of the superconducting thin films 2, 2' are in contact with each other. Combine and stack. At this time, the crystal orientations of the superconducting thin films 2 and 2 'are matched. The crystal orientation is known when the superconducting plate is produced. That is, when the superconducting plate is a substrate, since a single crystal is used as the base material of the substrate, the crystal orientation of the superconducting thin film deposited on the surface can be controlled. Further, when the superconducting plate is a wire, the crystal orientation of the metal tape serving as the base material can be controlled, so that the superconducting thin film deposited thereon can also control the crystal orientation. Alternatively, by providing an intermediate layer whose crystal orientation is controlled on the surface of the metal tape whose crystal orientation cannot be controlled, the crystal orientation of the superconducting thin film deposited thereon can be controlled.
In general, the superconducting plate 3 has an intermediate layer between the base material 1 and the superconducting thin film 2, but is omitted here.
A connecting superconducting thin film 4 is deposited on one or both of the thin film surfaces following the overlapped portion as shown in FIG. 1A, as shown in FIG. By this deposition, the connecting superconducting thin film 4 grows epitaxially with respect to the superconducting thin film 2, is continuously deposited on the side surface portion of the overlapping superconducting thin film 2 ′, and is superposed on the connecting superconducting thin film 4. , 2 'is single-crystallized to ensure superconductivity at the connection.
At this time, when a part of the superconducting thin film 2 'overlapping as shown in FIG. 2 is processed obliquely with respect to the substrate surface, the connecting superconducting thin film 4 grows epitaxially along the oblique processed surface 5, and the superconducting thin film overlapping. 2,2 'is single crystallized.
[0013]
In order to ensure the first method of the present invention, as shown in FIG. 3, superconducting thin films 4 and 4 'for connection are deposited on the upper and lower surfaces of the superconducting plate-like bodies 3 and 3' which are superposed, and the connection is made. It is preferable to form conductive protective films 6 and 6 'on the exposed surfaces of the superconducting thin films 4 and 4'. The formed conductive protective films 6 and 6 'may be covered with insulating coatings 7 and 7'. In FIG. 3, the obliquely machined surface shown in FIG. 2 is omitted, but it is preferable to provide the superconducting thin films 2 and 2 ′ with an obliquely machined surface.
In the first method of the present invention, since there is no bonding between the base materials of the superconducting plate to be connected, connection is possible even if the types of both base materials to be connected are different or there is a difference in dimensions. It is a means that can also be applied when connecting a thin film wire and a thin film substrate.
[0014]
The superconductor used here is an RE123-based material for the superconducting thin film, yttria-stabilized zirconia (YSZ), CeO2 or the like for the intermediate layer, Ni, Ni-Fe alloy (trade name: Hastelloy, etc.) for the base material. ), Ni composite material or the like may be used. As a connection method, as a means for depositing a superconducting thin film, physical vapor deposition methods such as pulse laser vapor deposition (PLD), radio frequency (RF) sputtering, thermal co-evaporation, chemical vapor deposition (MOCVD, etc.), liquid phase epitaxy, etc. A chemical deposition method such as a method (LPE) or an organic metal deposition method (MOD) may be used. Moreover, it is preferable to produce a noble metal by a sputtering method as a protective film. The material for the insulating coating is preferably a resin or a ceramic adhesive.
The fourth aspect of the present invention is schematically shown in FIGS. 1a, 2 and 3.
[0015]
The second method of the present invention will be described with reference to the schematic diagrams of FIGS. As shown in FIG. 4A, the superconducting plate-like bodies 3 and 3 'connected with a certain distance are placed on the substrate 11 serving as a base and fixed. This fixing may be mechanical or scientific means. Superconducting plate-like bodies 3 and 3 'are composed of base materials 1 and 1' and superconducting thin films 2 and 2 '. The intermediate layer between the substrate and the superconducting thin film is omitted. Then, as shown in FIG. 4B, the connecting superconducting thin film 12 is deposited in the space portion on the substrate 11. By doing so, the connecting superconducting thin film 12 deposited on the substrate 11 is deposited in alignment with the superconducting thin films 2 and 2 'of the superconducting plates 3 and 3' in a single crystal form. Connect.
Although omitted in FIG. 4, if one or both of the superconducting thin films 2, 2 ′ of the superconducting plates 3, 3 ′ placed on the substrate 11 are processed obliquely with respect to the substrate surface. The superconducting thin film 12 for connection to be deposited grows epitaxially and tends to be in a state where the crystal orientation is aligned with the superconducting thin films 2 and 2 '.
[0016]
In order to make the second method of the present invention more reliable, as shown in FIG. That is, when the protective film 13 is formed on the surface of the deposit of the connecting superconducting thin film 12 produced in FIG. 4B, the superconducting thin film is protected from the outside. Furthermore, if it covers with the insulation coating 14 and fills between the base materials of the superconducting plate to be connected, the protection is ensured. If the insulation coating 14 is adjusted to the same height as the superconducting plate-like bodies 3 and 3 ', the protrusion of the connecting portion can be avoided.
Further, as shown in FIG. 5 (b), if the fixed substrate 11 is removed, the connecting portion can have the same thickness as the superconducting plate-like bodies 3 and 3 ', thereby reducing the uncomfortable feeling of the connecting portion. it can.
The superconducting plate used here may have the same content as that used in the first method, but the substrate used as the base promotes the epitaxial growth of the superconducting thin film for connection to be deposited. Is preferred. For example, a single crystal substrate such as MgO, LaAlO ₃ , or SrTiO ₃ (STO) may be used, or an orientation intermediate layer formed on sapphire may be used. Moreover, what provided the intermediate | middle layer oriented on the metal for substrates may be used. Further, a superconducting thin film laminated thereon can also be used.
The fifth aspect of the present invention corresponds to FIGS. 4b, 5a, and 5b when schematically shown.
[0017]
The third method of the present invention will be described with reference to the schematic diagram of FIG. This method is a method of repairing a defective portion of the superconducting plate-like body, and is slightly different in meaning from the above two connection methods, but is connected when using the superconducting plate-like body. As shown in FIG. 6, the first superconducting plate-like body 3 having the defective portion 15 is placed on a part of the superconducting thin film 2, and a good second superconducting plate-like body 18 prepared separately is placed on the substrate 16. With the superconducting thin film 17 facing down, the defective portions 15 are combined so as to contact each other. Also at this time, it is preferable to adjust the position so that the crystal orientations of the superconducting thin films 2 and 17 substantially coincide. The superconducting thin films 19 and 19 ′ are deposited on the ends of the placed superconducting plate 18 so that the superconducting thin films 2 and 17 of the superconducting plate 3 and the superconducting plate 18 are connected to the connecting superconducting thin film 19. , 19 ′ and single crystallized.
The superconducting plate 18 for repair used here is preferably the same as the superconducting plate 3 to be repaired, but another superconducting plate may be used as long as the superconducting thin films are similar to each other. I do not care.
FIG. 6 corresponds to the sixth aspect of the present invention when schematically illustrated.
As described above, the present invention shows a connection method according to the connection form of the superconducting thin film. Either of these is a means applicable to a superconducting plate having a wide variety of superconducting thin films.
[0018]
【Example】
Although the Example of this invention is shown below, since this invention has a wide application range, it is not limited to an Example.
In the following examples, a superconducting wire and a superconducting substrate having the following configuration are used for the superconducting plate.
As the superconducting wire, a Ni—Fe alloy (trade name: Hastelloy) was used for the base material, yttria stabilized zirconia (YSZ) was used for the intermediate layer, and HoBa ₂ Cu ₃ O _7-x (HoBCO) was used for the superconducting thin film. The wire has a width of 1 cm, a length of 30 cm, a thickness of 0.1 mm, and a critical current value (Ic) of about 30A. The HoBCO film has a thickness of about 1 μm.
As the superconducting substrate, a substrate in which a LaAlO ₃ single crystal was deposited as a base material and HoBCO of about 1 μm was deposited thereon was used. The size is 50 mm in diameter, 0.5 mm in thickness, and the critical current density (Jc) is about 3 × 10 ⁶ A / cm.
[0019]
(Example 1) As shown in FIG. 1 (a), two superconducting wires are prepared as superconducting plates 3 and 3 ', and a thin film deposition holder (with superconducting thin films 2 and 2' overlapped by 5 cm at the end) (Not shown). In this state, it was set in a radio frequency (RF) sputtering apparatus, and a HoBCO film as a superconducting thin film 4 for connection was deposited by about 1.5 μm as shown in FIG. In this state, the thin film deposition holder was moved to a direct current (DC) sputtering apparatus, and a silver thin film was formed as a conductive protective film 6 on the connecting superconducting thin film 4 as shown in FIG. Then, after covering the silver thin film and fixing the part corresponding to the insulating coating 7 with resin, it was removed from the thin film deposition holder. The superconducting current value (Ic) of the connected superconducting plate was 30 A, and it was confirmed that the connection was complete.
[0020]
(Embodiment 2) As shown in FIG. 1A, a superconducting thin film substrate is used for one superconducting plate 3 and a superconducting wire is used for the other superconducting plate 3 '. And fixed with a thin film deposition holder. By performing the same operation as in Example 1, 1.5 μm of HoBCO was deposited as a superconducting thin film 4 for connection as shown in FIG. 1B, and further conductive protection was performed by DC sputtering on it as shown in FIG. A silver thin film was deposited as the film 6. Thereafter, the film was removed from the thin film deposition holder, and the conductivity including the connecting portion was measured. As a result, it was confirmed that Ic was 30A.
[0021]
(Embodiment 3) A superconducting wire having a length of 5 cm is used as the substrate 11 shown in FIG. 4 (a), and two superconducting wires are used as superconducting plates 3 and 3 ', with a gap of 3 mm at the end. The substrate was placed with the opening substrate facing up. These widthwise ends are fixed by spot welding, and HoBCO is deposited in a thickness of 1.5 μm as a superconducting thin film 12 for connection shown in FIG. 4B by a pulse laser deposition method (PLD method) in a gap portion of 3 mm. did. After that, as shown in FIG. 5, a silver thin film was formed as a protective film 13 on the connecting superconducting film 12 by DC sputtering. In this state, the conductivity of the superconducting plate including the connecting portion was examined. As a result, Ic was 27A, indicating that the connection was normal.
[0022]
Example 4 An MgO single crystal substrate (10 mm square) was prepared as the substrate 11 shown in FIG. On top of this, two superconducting wires were placed as superconducting plate-like bodies 3 and 3 ′ with a gap of 3 mm at the end and the base material facing up. In this state, as shown in FIG. 4B, a HoBCO film was deposited as a superconducting thin film 12 for connection, and 1.5 μm was deposited in the gap portion using the PLD method. Thereafter, as shown in FIG. 5A, a silver thin film was formed as a protective film 13 by DC sputtering, and then a ceramic adhesive was filled as an insulating coating 14 so as to bury the stepped portion and fixed. Since the Ic of the superconducting plate having this connecting portion was 30 A, a normal connection could be made.
[0023]
Example 5 A silver single crystal substrate (10 mm square) was prepared as the substrate 11 shown in FIG. On this, two superconducting wires are placed as superconducting plate-like bodies 3 and 3 'with a gap of 3 mm at the end and a base material facing upward, and the superconducting thin film 12 for connection shown in FIG. HoBCO was deposited in a gap portion of 1.5 μm. Thereafter, as shown in FIG. 5A, a silver thin film was formed as a conductive protective film 13 on the HoBCO thin film by a DC sputtering method, and a ceramic adhesive was used as the insulating coating 14 to cover it.
The resulting connection was etched using dilute nitric acid to remove the silver single crystal substrate. The connection part made here had almost the same thickness and width as the superconducting plate-like body, and the failure due to the swelling of the connection part could be removed. Also, the electrical conductivity is Ic of 26A, and there is no problem.
[0024]
(Example 6) A superconducting thin film near the center of the superconducting wire that is the superconducting plate-like body 3 was scratched at the tip of the needle. The Ic of this wire was usually 30 A, but it was 1 A or less due to the defective portion resulting from the scratch, resulting in a scratch defect. As shown in FIG. 6, the superconducting wire is placed with the superconducting thin film 2 on the center of the defective portion 15, and a superconducting wire which is a superconducting plate 18 cut to a length of 5 cm is formed on the base. The materials were stacked so that both superconducting films were in contact with each other. After superconducting plate-like bodies 3 and 18 were fixed by spot welding, superconducting thin films 19, 19 ′, specifically, HoBCO films were deposited on both ends of superconducting plate-like body 18 by using the PLD method. Thereafter, a silver thin film was formed on the HoBCO film by a DC sputtering method to obtain a conductive protective film. The superconducting plate repaired as described above recovered to Ic of 28A.
[0025]
【The invention's effect】
According to the present invention, it is possible to connect a superconducting plate-shaped body mainly composed of an oxide film that is difficult to connect without greatly reducing the superconducting current value after connection, without a large increase in cross section due to connection, and good workability. It will be a thing.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a first method of the present invention. (A) is the figure which piled up the superconducting plate-shaped object, (b) is the state connected with the superconducting film for a connection.
FIG. 2 is a schematic diagram of an example to which the first method of the present invention is applied.
FIG. 3 is a schematic diagram of an example showing an embodiment according to the first method of the present invention.
FIG. 4 is a schematic diagram showing a second method of the present invention. (A) is the figure which mounted the connection target object on the board | substrate, (b) is the state connected by the superconducting film for a connection.
FIG. 5 is a schematic diagram of an example in which the second method of the present invention is more reliably performed. (A) is a state where a protective film is deposited on the superconducting thin film for connection, and (b) is a state where the substrate is further removed.
FIG. 6 is a schematic view showing a third method of the present invention.
FIG. 7 is a connection schematic diagram shown in the prior art.
FIG. 8 is another example of a connection schematic diagram shown in the prior art.
FIG. 9 is an example of still another connection schematic diagram shown in the prior art.
[Explanation of symbols]
1,1 '. Substrate 2, 2 '. Superconducting thin film 3.3 '. Superconducting plate-like body 4.4 '. 4. Superconducting thin film for connection Obliquely processed surface 6, 6 '. Conductive protective film 7, 7 '. 11. Resin or ceramic adhesive Substrate 12. 12. Superconducting thin film for connection Conductive protective film 14. Insulation coating 15. Defective part 16. Base material 17. Superconducting thin film 18. Superconducting plate 19, 19 '. Connecting superconducting thin film 101. Base material 102. Intermediate layer 103. Oxide superconducting layer 104. Stabilized silver layer 105. Oxide superconducting plate 106. Solder 111. Base material 112. Intermediate layer 113. Oxide superconducting layer 114. Stabilized silver layer 115. Superconducting plate 116. Base material 117. Low melting point oxide superconductive layer 118. Superconducting tape for connection 121. Substrate 131. Connection layer 132. Connecting oxide superconducting layer 133. Oxide superconducting layer 134. Surface protective film 135. Oxide superconducting plate

Claims

A method of connecting a superconducting thin plate formed by forming a superconducting thin film on a base material, wherein the superconducting thin film surfaces of two superconducting thin plates to be connected are combined so that they are in contact with each other, and the contact is made after the crystal orientation of and both superconducting thin film is positioned adjusted to match approximately, in the thin film surface following the portion where the superconducting thin film is in contact, the superconducting thin film and depositing a superconducting thin film of the same kind, is the deposition A method of connecting a superconducting plate, wherein a conductive protective film is further formed on the surface of the superconducting film .

The superconducting plate-like body connection according to claim 1, further comprising a step of processing a part of one or both superconducting thin films of the superconducting plate-like body to be connected obliquely with respect to the substrate surface. Method.

The superconducting plate-like connection method according to claim 1 , wherein the protective film is further covered with an insulating coating.

A method of connecting a superconducting plate-like body in which a superconducting thin film is formed on a base material, each of the superconducting plate-like bodies to be connected being connected to a connecting substrate on each of the superconducting plates. The superconducting thin film surface of the plate is placed in contact with the surface of the connecting substrate, the crystal orientation of the superconducting thin film is substantially the same, and each end of the superconducting plate has a gap. After fixing on the connecting substrate, a superconducting thin film of the same type as the superconducting thin film is deposited in the gap portion of the connecting substrate , and a conductive protective film is further formed on the surface of the deposited superconducting thin film. A method for connecting a superconducting plate-like body.

The method for connecting a superconducting plate-like body according to claim 4 , further comprising a step of processing a part of one or both superconducting thin films of the superconducting plate-like body to be connected obliquely with respect to the substrate surface. .

6. The superconducting plate according to claim 4 or 5 , wherein the surface of the protective film is further covered with a resin or a ceramic adhesive to fill a gap between both substrates of the superconducting plate to be connected, and then the substrate is removed. How to connect the body.

A method of connecting a superconducting plate having a superconducting thin film formed on a substrate, the first superconducting plate having a defective portion in a part of the superconducting thin film, and a superconducting thin film separately prepared on the substrate Are combined with the superconducting thin film surface so that the superconducting thin film surface covers the defective portion and is in contact with each other, and any one of the superconducting thin films is formed on the thin film surface following the portion in contact with the superconducting thin film. A superconducting thin film of the same kind as in the above, and a conductive protective film is further formed on the surface of the deposited superconducting thin film .

After the crystal orientation of the superconducting thin film both in contact is located adjusted to match approximately, in the thin film surface following the portion where the superconducting thin film is in contact, claim to deposit a superconducting thin film of any one of the superconducting thin film and the same type 7 The connection method of the superconducting plate-like body as described in 2.

A first superconducting plate having a superconducting thin film formed on a substrate, and the superconducting thin film are in contact with the surface of the superconducting thin film of the first superconducting plate, and the crystal orientations of both superconducting thin films are approximately A superconducting thin film of the same type as the superconducting thin film is deposited on the thin film surface that follows the second superconducting plate disposed so as to coincide with the portion where the superconducting thin film is in contact with the superconducting thin film. A superconducting plate-like connecting portion , wherein a conductive protective film is further formed on the surface .

The end of the first superconducting plate with the superconducting film formed on the substrate and the end of the second superconducting plate with the superconducting thin film formed on the separately prepared substrate are spaced from each other. The superconducting thin film is formed in the gap so as to connect the superconducting thin film of the first superconducting plate and the superconducting thin film of the second superconducting plate, and the superconducting thin film crystal orientation, a superconducting thin film of the first and substantially coincides with the crystal orientation of the superconducting thin film of superconductor shaped bodies and the one of the crystal orientation of the second superconductor shaped body, said first superconducting plate-like body And a superconducting thin film formed so as to connect the superconducting thin film of the second superconducting plate to the surface of the superconducting thin film .

A superconducting plate formed by forming a superconducting thin film on a substrate, and superconducting on a separately prepared substrate on the surface of the superconducting thin film of the first superconducting plate having a defective portion in a part of the superconducting thin film The superconducting thin film surface of the second superconducting plate formed with the thin film is combined so as to cover and contact the defective portion, and the thin film surface following the portion in contact with the superconducting thin film is the same type as the superconducting thin film. A superconducting plate-like connecting portion , wherein a superconducting thin film is deposited , and a conductive protective film is further formed on the surface of the deposited superconducting thin film .