JP4132032B2

JP4132032B2 - Vacuum container viewing window and vacuum container

Info

Publication number: JP4132032B2
Application number: JP2002314404A
Authority: JP
Inventors: 敦司笹川
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2002-10-29
Filing date: 2002-10-29
Publication date: 2008-08-13
Anticipated expiration: 2022-10-29
Also published as: JP2004149827A

Description

【０００１】
【発明の属する技術分野】
本発明は、半導体製造装置や電子機器等に使用される真空容器の内部を観察するための覗き窓および真空容器に関する。
【０００２】
【従来の技術】
従来、半導体製造装置や電子機器等に使用される真空容器の内部を観察するための真空容器の覗き窓は、ガラス、石英、透明な合成樹脂等から成る板状の窓部材を用い、窓部材の外周部を枠状や円環状の２つの金属部材で挟み込み、その金属部材を真空容器にロウ付け、樹脂接着剤等による接着によって接合していた。あるいは、容器に開口が切ってあり、窓部材の外周部を枠状や円環状の２つの金属部材で挟み込み、金属部材の一方を容器の開口の周囲にボルト締めしていた。この場合、１つの金属部材を用いて、その金属部材と容器の開口の周囲とで窓部材の外周部を挟み込む場合もある。また、半導体製造装置等に用いられる真空容器に組み込まれる覗き窓の場合、覗き窓の窓部材は、その外周部を気密を保持するための樹脂製や金属製のＯリングを介して２つの金属部材で挟み込むことにより気密の確保が行われていた。
【０００３】
しかしながら、真空容器においては、所望の真空度へ短時間で到達する必要性から、真空容器の内面からのアウトガスの促進のためにベーキングといった加熱処理を施すが、樹脂製のＯリングを使用した覗き窓ではＯリングがベーキング温度に耐えることができないといった問題点があった。また、覗き窓の窓部材として合成樹脂製のものを使用した場合、窓部材がベーキング温度に耐えられない、またはアウトガスの多さから真空容器に用いることができないという問題点があった。
【０００４】
このような問題点を解消するために、近年、覗き窓の窓部材としてサファイア製のものが用いられるようになった（例えば、下記の特許文献１参照）。
【０００５】
サファイア製の窓部材は、その表面にメタライズ層を被着することにより金属とのロウ付けが可能となるため、サファイア製の窓部材を金属部材にロウ付けすることにより、高い気密性を確保した覗き窓の製作が可能となった。また、サファイア製の窓部材の表面からのガス放出は金属の場合と同等であるため、アウトガスは特に問題とならない。さらに、ロウ付けは780℃以上の融点のロウ材を用いて行なうことが可能であるため、一般的なベーキング温度である250〜350℃の温度に対しても十分に気密を保持できる。
【０００６】
しかしながら、サファイア製の窓部材と金属部材とのロウ付けは、サファイアおよび金属部材の材料の特性を十分理解したうえでその構造を決めなければ、窓部材が割れて気密の確保ができない場合がある。その場合、窓部材の割れにより容器内部の観察が十分にできなくなる。これは、サファイア製の窓部材と金属部材との熱膨張係数が異なるためであり、それらが高温でロウ付けされた後に常温まで降温する際に、熱膨張係数の違いから各部材に応力が発生するからである。
【０００７】
このため、サファイア製の窓部材がロウ付けされる金属部材の材料として、比較的サファイアに熱膨張係数が近く、かつ真空容器の材料として最も多く用いられているステンレスとの溶接が容易な、鉄（Ｆｅ）−ニッケル（Ｎｉ）合金や鉄（Ｆｅ）−ニッケル（Ｎｉ）−コバルト（Ｃｏ）合金などが用いられる。しかし、これらの金属も、サファイアの熱膨張係数約５×10^-6に対し、Ｆe−Ｎｉ合金で約８×10^-6、Ｆe−Ｎｉ−Ｃｏ合金で約６×10^-6というように熱膨張係数の違いがあるため、ロウ付け時に発生する応力を十分緩和できる構造でない場合、窓部材が割れるという問題点がある。
【０００８】
また、図３の断面図に示すように、金属部材11の内周面に、窓部材10の位置決めのために段差11ｂを設け、その段差11ｂに窓部材10の一主面の外周部をロウ付けした構成のものが用いられることがある。
【０００９】
【特許文献１】
特開平８−246148号公報
【００１０】
【発明が解決しようとする課題】
しかしながら、上記従来の図３の構成の覗き窓においては、ロウ付け部である段差11ｂから一端までの金属部材11の肉厚が厚くなるため、ロウ付け時に窓部材14に加わる応力が大きくなる。即ち、ロウ付け時の金属部材11の変形により金属部材11の内周面の段差11bの角部が窓部材10の角部に大きな応力を加え、窓部材10が割れるという問題が発生していた。
【００１１】
従って、本発明は上記従来の問題点に鑑みて完成されたものであり、その目的は、窓部材と金属部材とのロウ付けによる接合の接合強度を向上させて窓部材における気密性を向上させ、また窓部材に加わる応力を軽減することによって窓部材に割れが生じない信頼性の高い覗き窓およびそれを用いた真空容器とすることである。
【００１２】
【課題を解決するための手段】
本発明の真空容器の覗き窓は、筒状の金属部材と、その内周面の一部に側面が全周にわたってロウ材を介して接合されたサファイアから成る窓部材とを具備した真空容器の覗き窓において、前記金属部材は、内周面の前記窓部材が接合される部位に前記窓部材の一主面の外周部が接合される凸部が全周にわたって連続して形成されており、前記窓部材は、側面にメタライズ層が全周にわたって被着されているとともに、前記一主面の外周部に外周端から前記凸部よりも前記窓部材の中心側へ前記凸部の軸方向の厚みの０．５乃至２倍の長さで突出した位置までメタライズ層が全周にわたって被着されていることを特徴とする。
【００１３】
本発明の覗き窓は、金属部材は、その内周面の窓部材が接合される部位に窓部材の一主面の外周部が接合される凸部が全周にわたって連続して形成されていることから、金属部材から窓部材に加わる応力を軽減することができ、その結果、窓部材に割れが生じないようにすることができる。
【００１４】
また、窓部材は、側面にメタライズ層が全周にわたって被着されているとともに、一主面の外周部に外周端から凸部よりも窓部材の中心側へ凸部の軸方向の厚みの0.5乃至２倍の長さで突出した位置までメタライズ層が全周にわたって被着されていることから、窓部材の一主面の外周部のメタライズ層の内周側と凸部との間にロウ材の大きなメニスカスが形成されることとなり、その結果、窓部材と金属部材とのロウ付けによる接合部の接合強度が向上し、窓部材における気密性が向上することとなり、また、接合部において金属部材から窓部材に加わる応力を緩和することができる。従って、接合部の信頼性が高いものとなる。
【００１５】
本発明の真空容器は、容器の壁面に形成された内外を貫通する開口の周囲に、上記本発明の覗き窓が接合された真空容器であって、前記覗き窓の金属部材の一端が前記窓部材に対して前記凸部が前記容器の内側に位置するように接合されていることを特徴とする。
【００１６】
本発明の真空容器は、上記の構成により、覗き窓の接合部の信頼性が高いことから、真空の保持の信頼性が高いものとなる。
【００１７】
【発明の実施の形態】
本発明の覗き窓について以下に詳細に説明する。図１は本発明の覗き窓について実施の形態の一例を示す断面図である。この図において、10は窓部材、11は金属部材、11ａは凸部、12はロウ材、13はメタライズ層である。また、図２は図１のロウ付け部付近の部分拡大断面図である。なお、図１，図２において、図３と同じ部分には同じ符号を付している。
【００１８】
本発明の覗き窓は、略円筒状の金属部材11と、その内周面の一部に側面が全周にわたってロウ材12を介して接合されたサファイアから成る略円板状の窓部材10とを具備し、金属部材11は、内周面の窓部材10が接合される部位に窓部材10の一主面の外周部が接合される凸部11ａが全周にわたって連続して形成されており、窓部材10は、側面にメタライズ層13が全周にわたって被着されているとともに、一主面の外周部に外周端から凸部11ａよりも窓部材10の中心側へ凸部11ａの軸方向の厚みの0.5乃至２倍の長さで突出した位置までメタライズ層13が全周にわたって被着されている。
【００１９】
本発明の覗き窓は、図１に示すように、金属部材11の内周面に凸部11ａを設け、その凸部11ａに窓部材10を配置しロウ付けすることにより、窓部材14の側面のみのロウ付けに比べてロウ付け面積が大幅に広くなり、接合強度が大幅に向上する。
【００２０】
凸部11ａの長さ、即ち金属部材11の内周面からの内側への突出長さは、0.5〜２ｍｍが好ましい。0.5ｍｍより短いと、凸部11ａと窓部材10とのロウ付け面積が十分に確保できないため、凸部11ａを設けたことによる接合強度の向上の効果が小さくなる。また、２ｍｍを超えると、金属部材11と窓部材10との熱膨張係数の違いによるロウ付け時の径方向の応力が大きくなり、窓部材10が割れるなどの問題が発生する。さらに、凸部11ａの飛び出しにより窓部材10の有効可視領域が狭くなる。
【００２１】
また、凸部11ａの軸方向の厚みは0.3〜２ｍｍが好ましい。0.3ｍｍより薄いと、強度が不足し、ロウ付け時の応力による変形が大きくなる。また、加工時の変形も大きくなり、製作が困難となる。２ｍｍより厚くなると、ロウ付け時に窓部材10に加わる応力が大きくなり、窓部材10が割れるなどの問題が発生し易くなる。
【００２２】
本発明において、窓部材10の凸部11ａとのロウ付け部に形成されるメタライズ層13は、窓部材10の一主面の外周部において凸部11ａよりも中心側まで形成されていることにより、メタライズ層13の窓部材10の中心側の端部（内周側の端部）に滑らかで大きなロウ材12のメニスカスを形成することができる。その結果、ロウ付け時に発生する、窓部材10と金属部材11との熱膨張係数差による応力を緩和することができる。
【００２３】
このメタライズ層13の凸部11ａから窓部材10の中心側への突出長さは、図２に示すように、凸部11ａの軸方向の厚みＷの0.5乃至２倍（0.5Ｗ乃至２Ｗ）であることが好ましい。0.5倍より小さいと、ロウ材12のメニスカスの形成が十分にされず、応力を緩和する効果が十分に得られない。また、２倍より大きくなると、ロウ材12がメタライズ層13の内側の端まで流れていかないとともに、覗き窓の有効可視領域を狭くすることとなり、好ましくない。
【００２４】
また、金属部材11の材質は、サファイアの熱膨張係数に近い金属であるということから、Ｆｅ−Ｎｉ合金，Ｆｅ−Ｎｉ−Ｃｏ合金，モリブデン（Ｍｏ），白金（Ｐｔ），チタン（Ｔｉ），ニオブ（Ｎｂ）などがよい。また、ロウ材12の材質は、400〜600℃の高温で溶融等の液化を生じないものがよく、Ａｇ系（Ａｇを主成分としたもの），Ａｕ系（Ａｕを主成分としたもの），Ａｇ−Ｃｕ合金系等のロウ材がよい。
【００２５】
また、窓部材10に形成されたメタライズ層13は、Ｍｏ−Ｍｎ，Ｗ−Ｍｎ，Ｃｕ−Ｔｉ，Ａｇ−Ｃｕ−Ｔｉ等から成り、その表面にニッケル（Ｎｉ）メッキ層を被着した２層構造である。メタライズ層13の厚みは５〜30μｍが好ましく、５μｍより薄いと、ロウ材12の浸食によりメタライズ層13の密着強度が低下して気密の破れが発生し易くなり、30μｍより厚いと、メタライズ層13と窓部材10との熱膨張係数差によりメタライズ層13に加わる応力が大きくなり、メタライズ層13に亀裂が生じ易くなる。
【００２６】
本発明の真空容器は、容器の壁面に形成された内外を貫通する開口の周囲に、本発明の覗き窓の金属部材11の一端が窓部材10に対して凸部11ａが容器の内側に位置するように接合されている。金属部材11の接合は、その一端を金属から成る容器の開口の周囲にロウ付けしたり、金属部材11の一端に鍔部を設けてその鍔部を容器の開口の周囲にボルト締めすることによって行なわれる。また、容器の開口は、容器に突出するように設けられたパイプ等の筒状部の開口であってもよい。なお、本発明の真空容器は、特に図示はしないが、半導体製造装置の真空チャンバ，電子顕微鏡の電子加速装置（電子銃），粒子加速器等に使用されるものである。
【００２７】
【実施例】
本発明の覗き窓の実施例について以下に説明する。
【００２８】
本発明の実施例として、図１に示す構成の覗き窓を以下のようにして製作した。外径30ｍｍ、厚さ２ｍｍの円板状のサファイア製の窓部材10を用意した。窓部材10の側面および一主面の外周端から３ｍｍの幅の部位に、Ｍｏ粉末とＭｎ粉末と酸化ケイ素（ＳｉＯ₂）粉末とに有機バインダ、溶剤を混合してなる金属ペーストを、10μｍの厚さとなるように印刷塗布し、乾燥後加湿したフォーミングガス中で1400℃の温度で焼成して、メタライズ層13の下地のメタライズ金属層を形成した。さらに、メタライズ金属層の表面にＮｉメッキ層を電解メッキ法により約２μｍの厚さで被着して、メタライズ層13を形成した。
【００２９】
次に、窓部材10の外径より0.1ｍｍだけ大きい内径で、厚みが0.5ｍｍ、長さが30ｍｍの円筒形であり、一端より10ｍｍの内周面の部位に凸部11ａが形成されたＦｅ−Ｎｉ−Ｃｏ合金から成る金属部材11を用意した。凸部11ａの内側への突出長さは２ｍｍとし、軸方向の厚みは１ｍｍとした。金属部材11の全面にはＮｉメッキ層を電解メッキ法により約２μｍの厚さで被着した。
【００３０】
この金属部材11の内側の凸部11ａに、メタライズ層13を形成した窓部材10を、メタライズ層13が形成されている部位が凸部11ａの一方の角部に当接するように配置した。さらに、窓部材10のメタライズ層13がない主面と金属部材11の内周面との間の角部に沿って、太さの直径が0.8ｍｍでＡｇ−Ｃｕ合金からなるロウ材12のプリフォームを設置した。そのロウ材12のプリフォームを820℃に加熱して、窓部材10の側面と金属部材11の内周面との間の隙間、および窓部材10の一主面の外周部のメタライズ層13と凸部11ａとの間の隙間に、溶融したロウ材12を毛細管現象により侵入させ、窓部材10と金属部材11とを接合した。これにより製作されたものをサンプルＡとした。
【００３１】
比較例１として、凸部11ａの内側への突出長さを0.3ｍｍ、窓部材10の一主面の外周端からのメタライズ層13の幅を1.3ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＢとした。
【００３２】
比較例２として、凸部11ａの内側への突出長さを３ｍｍ、窓部材10の一主面の外周端からのメタライズ層13の幅を４ｍｍとし、それ以外は上記実施例と同様に製作したものをサンプルＣとした。
【００３３】
サンプルＡ〜Ｃの接合部を双眼顕微鏡を用いて観察し、異常の有無を検査した結果を表１に示す。
【００３４】
【表１】

【００３５】
表１より、サンプルＡ，Ｂには異常は見られなかったが、サンプルＣは窓部材10の凸部11ａとの接合部付近に３分の２周程度にわたりクラックの発生が確認された。
【００３６】
また、上記と同様に製作した別のサンプルＡ，Ｂについて、金属部材11の凸部11ａの無い側から水を注入し圧力を加え、クラックが発生する値を調べた。その結果を表２に示す。
【００３７】
【表２】

【００３８】
表２より、サンプルＢに比べサンプルＡは大きな耐圧力を有することが判った。また、金属部材11の変形がサンプルＢの方が大きかった。
【００３９】
また、上記と同様に製作した別のサンプルＡ、凸部11ａの軸方向の厚みを0.2ｍｍとしたサンプルＤ、同様に厚みを３ｍｍとしたサンプルＥを製作し、接合部を双眼顕微鏡で観察し異常がないか検査した結果を表３に示す。
【００４０】
【表３】

【００４１】
表３より、サンプルＡは異常が見られなかった。サンプルＤはロウ付け時の応力により、金属部材11の凸部11ａ付近が大きく変形した。また、サンプルＥは窓部材10の凸部11ａとの接合部付近の全周にクラックの発生が確認された。
【００４２】
また、上記と同様に製作した別のサンプルＡと、凸部11ａより内側へのメタライズ層13の突出長さを0.2ｍｍとしたサンプルＦ、同様に突出長さを３ｍｍとしたサンプルＧを製作し、接合部を双眼顕微鏡で観察し異常がないか検査した結果を表４に示す。
【００４３】
【表４】

【００４４】
表４より、サンプルＡは異常が見られなかったが、サンプルＦは窓部材10の凸部11ａとの接合部付近の全周にクラックの発生が確認された。また、サンプルＧは、接合部の異常は見られなかったが、メタライズ層13の内側の端までロウ材12が流れなかったため、メタライズ層13の内側１ｍｍ程度の幅の部位にはロウ材12が流れておらず、サンプルＡに比べて有効可視領域を狭くするだけの結果となった。
【００４５】
以上より、サンプルＡが窓部材10と金属部材11との熱膨張係数差に起因する応力によるクラックが見られず、耐圧力、有効可視領域について優れていることがわかった。
【００４６】
なお、本発明は上記実施の形態および実施例に限定されず、本発明の要旨を逸脱しない範囲内で種々の変更を施すことは何等差し支えない。例えば、本発明の覗き窓は、気密を必要とする真空容器の内部の観察に使用できるが、真空容器の内部の対象物を光学的、電気的に計測するための窓としても使用できる。
【００４７】
【発明の効果】
本発明の真空容器の覗き窓は、金属部材はその内周面の窓部材が接合される部位に窓部材の一主面の外周部が接合される凸部が全周にわたって連続して形成されていることにより、金属部材から窓部材に加わる応力を軽減することができ、その結果、窓部材に割れが生じないようにすることができる。
【００４８】
また、窓部材は、側面にメタライズ層が全周にわたって被着されているとともに、一主面の外周部に外周端から凸部よりも窓部材の中心側へ凸部の軸方向の厚みの0.5乃至２倍の長さで突出した位置までメタライズ層が全周にわたって被着されていることにより、窓部材の一主面の外周部のメタライズ層の内周側と凸部との間にロウ材の大きなメニスカスが形成されることとなり、その結果、窓部材と金属部材とのロウ付けによる接合部の接合強度が向上し、窓部材における気密性が向上することとなり、また、接合部において金属部材から窓部材に加わる応力を緩和することができる。従って、接合部の信頼性が高い覗き窓となる。
【００４９】
本発明の真空容器は、容器の壁面に形成された内外を貫通する開口の周囲に、上記本発明の覗き窓の金属部材の一端が窓部材に対して凸部が容器の内側に位置するように接合されていることにより、覗き窓の接合部の信頼性が高いことから、真空の保持の信頼性が高いものとなる。
【図面の簡単な説明】
【図１】本発明の覗き窓について実施の形態の例を示す断面図である。
【図２】図１の覗き窓におけるろう付け部付近の拡大断面図である。
【図３】従来の覗き窓の一例を示す断面図である。
【付号の説明】
10：窓部材
11：金属部材
11ａ：凸部
12：ロウ材
13：メタライズ層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a viewing window and a vacuum container for observing the inside of a vacuum container used in a semiconductor manufacturing apparatus, an electronic device, or the like.
[0002]
[Prior art]
Conventionally, the observation window of a vacuum vessel for observing the inside of a vacuum vessel used in a semiconductor manufacturing apparatus or an electronic device uses a plate-like window member made of glass, quartz, transparent synthetic resin, etc. Was sandwiched between two metal members having a frame shape or an annular shape, and the metal member was brazed to a vacuum vessel and bonded by a resin adhesive or the like. Alternatively, an opening is cut in the container, the outer peripheral portion of the window member is sandwiched between two metal members having a frame shape or an annular shape, and one of the metal members is bolted around the opening of the container. In this case, a single metal member may be used to sandwich the outer periphery of the window member between the metal member and the periphery of the opening of the container. Further, in the case of a viewing window incorporated in a vacuum vessel used in a semiconductor manufacturing apparatus or the like, the window member of the viewing window is made of two metals via a resin or metal O-ring for keeping the outer peripheral portion airtight. Airtightness has been ensured by sandwiching with members.
[0003]
However, in a vacuum vessel, heat treatment such as baking is performed to promote outgas from the inner surface of the vacuum vessel because it is necessary to reach a desired degree of vacuum in a short time, but peeping using a resin O-ring is performed. There is a problem that the O-ring cannot withstand the baking temperature in the window. Further, when a window made of a synthetic resin is used as the window member for the viewing window, there is a problem that the window member cannot withstand the baking temperature or cannot be used for a vacuum container due to a large amount of outgas.
[0004]
In order to solve such a problem, in recent years, a sapphire member has been used as a window member of a viewing window (for example, see Patent Document 1 below).
[0005]
Since the sapphire window member can be brazed with metal by applying a metallized layer on the surface, high airtightness is secured by brazing the sapphire window member to the metal member. A viewing window can now be produced. Moreover, since the gas emission from the surface of the window member made of sapphire is the same as that of metal, outgas is not a problem. Furthermore, since brazing can be performed using a brazing material having a melting point of 780 ° C. or higher, the airtightness can be sufficiently maintained even at a temperature of 250 to 350 ° C. which is a general baking temperature.
[0006]
However, the brazing of the sapphire window member and the metal member may not be able to ensure airtightness by cracking the window member unless the structure is determined after fully understanding the characteristics of the materials of the sapphire and the metal member. . In that case, the inside of the container cannot be sufficiently observed due to the crack of the window member. This is because the sapphire window member and the metal member have different thermal expansion coefficients, and when they are brazed at a high temperature and then cooled to room temperature, stress is generated in each member due to the difference in the thermal expansion coefficient. Because it does.
[0007]
For this reason, as a metal member material to which a sapphire window member is brazed, iron has a thermal expansion coefficient relatively close to that of sapphire and can be easily welded to stainless steel, which is most frequently used as a vacuum vessel material. An (Fe) -nickel (Ni) alloy, an iron (Fe) -nickel (Ni) -cobalt (Co) alloy, or the like is used. However, these metals also have a thermal expansion coefficient of about 5 × 10 ⁻⁶ for sapphire, about 8 × 10 ^{−6 for} the Fe—Ni alloy and about 6 × 10 ^{−6 for} the Fe—Ni—Co alloy. Since there is a difference in expansion coefficient, there is a problem that the window member breaks if the structure does not sufficiently relax the stress generated during brazing.
[0008]
Further, as shown in the cross-sectional view of FIG. 3, a step 11b is provided on the inner peripheral surface of the metal member 11 for positioning the window member 10, and the outer peripheral portion of one main surface of the window member 10 is brazed to the step 11b. The attached configuration may be used.
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 8-246148
[Problems to be solved by the invention]
However, in the conventional viewing window having the configuration shown in FIG. 3, the thickness of the metal member 11 from the step 11b, which is the brazing portion, to the one end is increased, so that the stress applied to the window member 14 during brazing increases. That is, the deformation of the metal member 11 at the time of brazing causes a problem that the corner portion of the step 11b on the inner peripheral surface of the metal member 11 applies a large stress to the corner portion of the window member 10 and the window member 10 breaks. .
[0011]
Accordingly, the present invention has been completed in view of the above-described conventional problems, and its purpose is to improve the airtightness of the window member by improving the bonding strength of the window member and the metal member by brazing. Another object of the present invention is to provide a highly reliable viewing window that does not cause cracks in the window member by reducing the stress applied to the window member, and a vacuum container using the same.
[0012]
[Means for Solving the Problems]
Viewing window of the vacuum vessel of the present invention, a vacuum vessel equipped with a cylindrical metal member, an inner side surface in a part of the peripheral surface and formed Ru window member from sapphire which is joined via a brazing material over the entire circumference thereof In the viewing window, the metal member is formed such that a convex portion where the outer peripheral portion of one main surface of the window member is joined to the portion of the inner peripheral surface where the window member is joined is continuously formed over the entire circumference. The window member has a metallized layer deposited on its side surface over the entire circumference, and the axial direction of the convex portion from the outer peripheral end to the center side of the window member from the outer peripheral end to the outer peripheral portion of the one main surface. The metallized layer is deposited over the entire circumference up to a position protruding at a length of 0.5 to 2 times the thickness.
[0013]
In the viewing window of the present invention, the metal member is formed such that a convex portion where the outer peripheral portion of one main surface of the window member is joined is continuously formed over the entire circumference at a portion where the window member of the inner peripheral surface is joined. Therefore, the stress applied to the window member from the metal member can be reduced, and as a result, the window member can be prevented from cracking.
[0014]
The window member has a metallized layer deposited on the side surface over the entire circumference, and the axial thickness of the convex portion from the outer peripheral end to the center side of the window member to the outer peripheral portion of one main surface is 0.5. Since the metallized layer is deposited over the entire circumference up to a position that protrudes twice as long, the brazing material is provided between the inner peripheral side of the metallized layer on the outer peripheral part of one main surface of the window member and the convex part. A large meniscus is formed. As a result, the joint strength of the joint portion by brazing the window member and the metal member is improved, and the air tightness of the window member is improved. The stress applied to the window member can be relaxed. Therefore, the reliability of the joint is high.
[0015]
The vacuum container of the present invention is a vacuum container in which the viewing window of the present invention is joined around an opening formed on the wall surface of the container that penetrates the inside and outside, and one end of the metal member of the viewing window is the window. It is characterized by joining with respect to the member so that the convex part may be located inside the container.
[0016]
The vacuum container according to the present invention has a high reliability of holding a vacuum because of the high reliability of the joint portion of the observation window due to the above configuration.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The viewing window of the present invention will be described in detail below. FIG. 1 is a sectional view showing an example of an embodiment of a viewing window according to the present invention. In this figure, 10 is a window member, 11 is a metal member, 11a is a convex portion, 12 is a brazing material, and 13 is a metallized layer. FIG. 2 is a partially enlarged cross-sectional view of the vicinity of the brazing portion of FIG. 1 and 2, the same parts as those in FIG. 3 are denoted by the same reference numerals.
[0018]
The viewing window of the present invention includes a substantially cylindrical metal member 11, and a substantially disc-shaped window member 10 made of sapphire whose side surface is joined to a part of its inner circumferential surface via a brazing material 12 over the entire circumference. The metal member 11 has a convex portion 11a continuously formed over the entire circumference at a portion where the outer peripheral portion of one main surface of the window member 10 is joined to a portion where the window member 10 on the inner peripheral surface is joined. The window member 10 has a metallized layer 13 attached to the side surface over the entire circumference, and the axial direction of the convex portion 11a from the outer peripheral end to the center side of the window member 10 from the outer peripheral end to the outer peripheral portion of one main surface. The metallized layer 13 is deposited over the entire circumference to a position protruding at a length 0.5 to 2 times the thickness.
[0019]
As shown in FIG. 1, the viewing window of the present invention is provided with a convex portion 11 a on the inner peripheral surface of the metal member 11, and the window member 10 is disposed on the convex portion 11 a and brazed to thereby form a side surface of the window member 14. Compared with brazing with only brazing, the brazing area is greatly increased and the bonding strength is greatly improved.
[0020]
As for the length of the convex part 11a, ie, the protrusion length to the inner side from the internal peripheral surface of the metal member 11, 0.5-2 mm is preferable. If it is shorter than 0.5 mm, a sufficient brazing area between the convex portion 11a and the window member 10 cannot be secured, and the effect of improving the bonding strength due to the provision of the convex portion 11a is reduced. On the other hand, if the thickness exceeds 2 mm, the stress in the radial direction during brazing due to the difference in the thermal expansion coefficient between the metal member 11 and the window member 10 increases, causing problems such as cracking of the window member 10. Further, the effective visible region of the window member 10 is narrowed by the protrusion of the convex portion 11a.
[0021]
Further, the axial thickness of the convex portion 11a is preferably 0.3 to 2 mm. If it is thinner than 0.3 mm, the strength is insufficient, and deformation due to stress during brazing increases. Also, deformation during processing becomes large, making it difficult to manufacture. If it is thicker than 2 mm, the stress applied to the window member 10 during brazing increases, and problems such as cracking of the window member 10 tend to occur.
[0022]
In the present invention, the metallized layer 13 formed on the brazed portion of the window member 10 with the convex portion 11a is formed to the center side of the convex portion 11a in the outer peripheral portion of one main surface of the window member 10. In addition, a smooth and large meniscus of the brazing material 12 can be formed at the center side end portion (inner end side end portion) of the window member 10 of the metallized layer 13. As a result, it is possible to relieve the stress caused by the difference in thermal expansion coefficient between the window member 10 and the metal member 11 that occurs during brazing.
[0023]
The protruding length of the metallized layer 13 from the convex portion 11a toward the center of the window member 10 is 0.5 to 2 times (0.5W to 2W) the axial thickness W of the convex portion 11a as shown in FIG. Preferably there is. If it is less than 0.5 times, the formation of the meniscus of the brazing material 12 is not sufficient, and the effect of relaxing the stress cannot be obtained sufficiently. On the other hand, when it is larger than twice, the brazing material 12 does not flow to the inner end of the metallized layer 13, and the effective visible region of the observation window is narrowed.
[0024]
Further, since the material of the metal member 11 is a metal close to the thermal expansion coefficient of sapphire, Fe—Ni alloy, Fe—Ni—Co alloy, molybdenum (Mo), platinum (Pt), titanium (Ti), Niobium (Nb) is preferable. In addition, the material of the brazing material 12 is preferably one that does not cause liquefaction such as melting at a high temperature of 400 to 600 ° C., and is based on Ag (based on Ag) or Au (based on Au). A brazing material such as Ag-Cu alloy is preferable.
[0025]
Further, the metallized layer 13 formed on the window member 10 is made of Mo-Mn, W-Mn, Cu-Ti, Ag-Cu-Ti, etc., and has two layers with a nickel (Ni) plating layer deposited on the surface thereof. Structure. The thickness of the metallized layer 13 is preferably 5 to 30 μm, and if it is thinner than 5 μm, the adhesion strength of the metallized layer 13 is reduced due to the erosion of the brazing material 12, and airtight tearing is likely to occur. The stress applied to the metallized layer 13 increases due to the difference in thermal expansion coefficient between the window member 10 and the window member 10, and the metallized layer 13 is likely to crack.
[0026]
In the vacuum container of the present invention, one end of the metal member 11 of the viewing window of the present invention is positioned on the inner side of the container with respect to the window member 10 around the opening formed on the wall surface of the container. To be joined. The metal member 11 is joined by brazing one end around the opening of the container made of metal, or by providing a flange on one end of the metal member 11 and bolting the flange around the opening of the container. Done. Further, the opening of the container may be an opening of a cylindrical portion such as a pipe provided so as to protrude from the container. The vacuum container of the present invention is used for a vacuum chamber of a semiconductor manufacturing apparatus, an electron accelerator (electron gun) of an electron microscope, a particle accelerator, etc., although not particularly shown.
[0027]
【Example】
Examples of the viewing window of the present invention will be described below.
[0028]
As an example of the present invention, a viewing window having the configuration shown in FIG. 1 was manufactured as follows. A disk-shaped sapphire window member 10 having an outer diameter of 30 mm and a thickness of 2 mm was prepared. A metal paste obtained by mixing Mo powder, Mn powder, and silicon oxide (SiO ₂ ) powder with an organic binder and a solvent at a portion 3 mm wide from the outer peripheral edge of the side surface and one main surface of the window member 10 is 10 μm. A metallized metal layer as a base of the metallized layer 13 was formed by printing and coating to a thickness, followed by drying and baking in a humidified forming gas at a temperature of 1400 ° C. Further, a Ni plating layer was deposited on the surface of the metallized metal layer to a thickness of about 2 μm by electrolytic plating to form a metallized layer 13.
[0029]
Next, the inner diameter of the window member 10 is 0.1 mm larger than the outer diameter, the thickness is 0.5 mm, the length is 30 mm, and the cylindrical portion is 10 mm from one end. A metal member 11 made of a Ni—Co alloy was prepared. The projecting length to the inside of the convex portion 11a was 2 mm, and the axial thickness was 1 mm. A Ni plating layer was deposited on the entire surface of the metal member 11 to a thickness of about 2 μm by electrolytic plating.
[0030]
The window member 10 on which the metallized layer 13 is formed is disposed on the convex portion 11a on the inner side of the metal member 11 so that the portion where the metallized layer 13 is formed abuts one corner of the convex portion 11a. Further, along the corner between the main surface of the window member 10 where the metallized layer 13 is not present and the inner peripheral surface of the metal member 11, a brazing material 12 made of an Ag-Cu alloy having a diameter of 0.8 mm is provided. A renovation was set up. The preform of the brazing material 12 is heated to 820 ° C., the gap between the side surface of the window member 10 and the inner peripheral surface of the metal member 11, and the metallized layer 13 on the outer peripheral portion of one main surface of the window member 10 The molten brazing material 12 was caused to enter the gap between the convex portions 11a by capillary action, and the window member 10 and the metal member 11 were joined. The product thus manufactured was designated as Sample A.
[0031]
As Comparative Example 1, the protruding length to the inside of the convex portion 11a is 0.3 mm, the width of the metallized layer 13 from the outer peripheral end of one main surface of the window member 10 is 1.3 mm, and other than that, the same as in the above embodiment The manufactured sample was designated as Sample B.
[0032]
As Comparative Example 2, the protrusion length to the inner side of the convex portion 11a was 3 mm, the width of the metallized layer 13 from the outer peripheral end of one main surface of the window member 10 was 4 mm, and the others were manufactured in the same manner as in the above embodiment. This was designated as Sample C.
[0033]
Table 1 shows the results of observing the joints of Samples A to C using a binocular microscope and examining the presence or absence of abnormalities.
[0034]
[Table 1]

[0035]
From Table 1, no abnormality was found in Samples A and B, but it was confirmed that cracks occurred in Sample C in the vicinity of the joint portion with the convex portion 11a of the window member 10 over about two thirds.
[0036]
Further, with respect to the other samples A and B manufactured in the same manner as described above, water was injected from the side of the metal member 11 where the convex portion 11a was not present, and pressure was applied to examine the value at which cracks occurred. The results are shown in Table 2.
[0037]
[Table 2]

[0038]
From Table 2, it was found that Sample A had a greater pressure resistance than Sample B. Further, the deformation of the metal member 11 was larger in the sample B.
[0039]
In addition, another sample A manufactured in the same manner as described above, sample D in which the axial thickness of the convex portion 11a is 0.2 mm, and sample E in which the thickness is 3 mm are similarly manufactured, and the joint portion is observed with a binocular microscope. Table 3 shows the results of inspection for abnormalities.
[0040]
[Table 3]

[0041]
From Table 3, sample A showed no abnormality. In the sample D, the vicinity of the convex portion 11a of the metal member 11 was greatly deformed by the stress during brazing. In addition, generation of cracks was confirmed in sample E around the entire periphery of the joint portion of the window member 10 with the convex portion 11a.
[0042]
In addition, another sample A manufactured in the same manner as described above, a sample F in which the protruding length of the metallized layer 13 to the inner side of the convex portion 11a is 0.2 mm, and a sample G in which the protruding length is 3 mm are also manufactured. Table 4 shows the results of examining the bonded portion with a binocular microscope for inspection.
[0043]
[Table 4]

[0044]
From Table 4, no abnormality was observed in Sample A, but it was confirmed that Sample F was cracked around the entire periphery of the joint portion with the convex portion 11a of the window member 10. In Sample G, no abnormality was observed in the joint, but the brazing material 12 did not flow to the inner end of the metallized layer 13, so the brazing material 12 was not present in the inner portion of the metallized layer 13 with a width of about 1 mm. As a result, the effective visible region was narrowed as compared with Sample A.
[0045]
From the above, it was found that Sample A was superior in terms of pressure resistance and effective visible region without cracking due to stress caused by the difference in thermal expansion coefficient between the window member 10 and the metal member 11.
[0046]
It should be noted that the present invention is not limited to the above-described embodiments and examples, and various modifications may be made without departing from the scope of the present invention. For example, the viewing window of the present invention can be used for observing the inside of a vacuum vessel that requires airtightness, but can also be used as a window for optically and electrically measuring an object inside the vacuum vessel.
[0047]
【The invention's effect】
In the viewing window of the vacuum container according to the present invention, the metal member is formed such that a convex portion where the outer peripheral portion of one main surface of the window member is joined to the portion where the window member of the inner peripheral surface is joined is continuously formed over the entire circumference. Therefore, the stress applied to the window member from the metal member can be reduced, and as a result, the window member can be prevented from cracking.
[0048]
The window member has a metallized layer deposited on the side surface over the entire circumference, and the axial thickness of the convex portion from the outer peripheral end to the center side of the window member to the outer peripheral portion of one main surface is 0.5. A brazing material is provided between the inner peripheral side of the metallized layer on the outer peripheral part of one main surface of the window member and the convex part by the metallized layer being applied over the entire circumference up to a position protruding to a length twice as long. A large meniscus is formed. As a result, the joint strength of the joint portion by brazing the window member and the metal member is improved, and the air tightness of the window member is improved. The stress applied to the window member can be relaxed. Therefore, it becomes a viewing window with high reliability of the joint.
[0049]
In the vacuum container of the present invention, one end of the metal member of the viewing window of the present invention is located on the inner side of the container around the opening formed through the inside and outside of the wall surface of the container. Since the reliability of the joint portion of the viewing window is high, the vacuum holding reliability is high.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a viewing window according to the present invention.
FIG. 2 is an enlarged cross-sectional view of the vicinity of a brazed portion in the viewing window of FIG.
FIG. 3 is a cross-sectional view showing an example of a conventional viewing window.
[Explanation of number]
10: Window member
11: Metal parts
11a: convex part
12: brazing material
13: Metallized layer

Claims

A cylindrical metal member;
In viewing window of the vacuum vessel in which a part on the side surface is provided with a formed Ru window member from sapphire which is joined via a brazing material over the entire circumference of the inner peripheral surface thereof,
In the metal member, a convex portion where the outer peripheral portion of one main surface of the window member is bonded to the portion where the window member of the inner peripheral surface is bonded is continuously formed over the entire circumference,
In the window member, a metallized layer is attached to the side surface over the entire circumference, and from the outer peripheral end to the center side of the window member on the outer peripheral portion of the one main surface in the axial direction of the convex portion. An inspection window for a vacuum vessel, characterized in that the metallized layer is deposited over the entire circumference to a position protruding at a length 0.5 to 2 times the thickness.

2. A vacuum vessel in which a viewing window according to claim 1 is joined around an opening formed on a wall surface of the container that penetrates the inside and outside , wherein one end of a metal member of the viewing window is protruded from the window member. A vacuum container, wherein the parts are joined so as to be located inside the container.