JP2003133802A - High frequency window for microwave tube - Google Patents
High frequency window for microwave tubeInfo
- Publication number
- JP2003133802A JP2003133802A JP2001330252A JP2001330252A JP2003133802A JP 2003133802 A JP2003133802 A JP 2003133802A JP 2001330252 A JP2001330252 A JP 2001330252A JP 2001330252 A JP2001330252 A JP 2001330252A JP 2003133802 A JP2003133802 A JP 2003133802A
- Authority
- JP
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- Prior art keywords
- insulating member
- peripheral surface
- outer peripheral
- electrode
- lower ends
- Prior art date
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Abstract
(57)【要約】
【課題】 第二の絶縁性部材の内周面に面取り部を施さ
なくてもクラックが発生することを有効に防止しでき、
またマイクロ波の透過特性が向上した信頼性の高いマイ
クロ波管用高周波窓を提供すること。
【解決手段】 第一の絶縁性部材１３は、その厚さが太
さの４分の１以上２分の１未満であり、外周面のメタラ
イズ層１５ａの上下端がサファイアまたは石英から成る
第二の絶縁性部材１４の内周面のメタライズ層１５ｂの
上下端より上下方向にそれぞれ第二の絶縁性部材１４の
軸方向の長さの４分の１以上突出し、かつ外周面のメタ
ライズ層１５ａの軸方向の長さが第二の絶縁性部材１４
の軸方向の長さの３倍以下である。
(57) [Problem] To effectively prevent cracks from occurring even if a chamfer is not provided on the inner peripheral surface of a second insulating member,
It is another object of the present invention to provide a highly reliable microwave tube high-frequency window having improved microwave transmission characteristics. SOLUTION: A first insulating member 13 has a thickness of not less than ４ and less than の of a thickness, and upper and lower ends of a metallized layer 15a on the outer peripheral surface are made of sapphire or quartz. The upper and lower ends of the metalized layer 15b on the inner peripheral surface of the insulating member 14 protrude vertically in the vertical direction from the upper and lower ends of the metalized layer 15a on the outer peripheral surface. The axial length of the second insulating member 14
Is not more than three times the axial length.
Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、例えば進行波管や
クライストロン等のマイクロ波導波管や、マイクロ波導
波管のマイクロ波電力を利用する機器において、真空部
と外部導波管との間に真空気密性をもって接続されるマ
イクロ波管用高周波窓に関する。
【０００２】
【従来の技術】従来のマイクロ波管用高周波窓は、図２
の断面図に示すように、一端がマイクロ波発振器側の真
空容器Ｌに、他端が外部導波管Ｍに溶接等で接合されて
気密封止される筒状の外周電極１と、一端がマイクロ波
発振器側の電極Ｎに、他端が外部導波管Ｍ側の電極Ｏに
溶接等で接合されて気密封止される筒状の中心電極２と
を具備する。
【０００３】さらに、外周電極１と中心電極２との間を
塞ぐように、アルミナ（Ａｌ2Ｏ3）セラミックス等から
なる筒状の絶縁性部材４を具備する。この絶縁性部材４
は上面および下面から内周面にかけて面取り部Ｃが形成
されており、絶縁性部材４の外周面、内周面および面取
り部Ｃに、モリブデン−マンガン（Ｍｏ−Ｍｎ）等から
なるメタライズ層５が被着されている。そして、外周面
が外周電極１に、内周面が中心電極２に、ロウ材６によ
ってそれぞれロウ付けされる。
【０００４】絶縁性部材４の熱膨張係数は約８×１０-6
／℃（室温〜８００℃）であり、無酸素銅から成る中心
電極２の熱膨張係数は約２０×１０-6／℃（室温〜８０
０℃）であり、大きく相違することから、ロウ付け工程
の降温過程において絶縁性部材４のロウ付け部には中心
電極２の熱収縮による引張り応力が発生する。そして、
絶縁性部材４の内周面の上下端に面取り部Ｃを形成して
ロウ付けすることにより、ロウ材６のメニスカスを形成
して応力緩和をすることができる。このことから、絶縁
性部材４のロウ付け部にクラックが発生するのを有効に
防止することができる。
【０００５】このようにして、マイクロ波発振器の真空
容器Ｌを気密に封止し、マイクロ波発振器で発生したマ
イクロ波を絶縁性部材４を透過させて外部導波管Ｍに導
入することができるマイクロ波管用高周波窓となる。
【０００６】
【発明が解決しようとする課題】しかしながら、マイク
ロ波を透過させる絶縁性部材４の内周面にはメタライズ
層５が被着された面取り部Ｃがあるため、マイクロ波の
透過時にメタライズ層５によってマイクロ波が反射して
透過ロスが発生し、高周波特性が低下するという問題点
を有していた。
【０００７】従って、本発明は、上記従来技術における
問題点に鑑み完成されたものであり、その目的は、絶縁
性部材の内周面に面取り部を施さなくてもクラックが発
生することを有効に防止しでき、またマイクロ波の透過
特性が向上した信頼性の高いマイクロ波管用高周波窓を
提供することにある。
【０００８】
【課題を解決するための手段】本発明のマイクロ波管用
高周波窓は、筒状の外周電極と、該外周電極の内側に同
心状に配置された筒状の中心電極と、該中心電極の内側
面の所定部位に外周面がメタライズ層を介してロウ付け
された筒状の第一の絶縁性部材と、前記外周電極と前記
中心電極との間を塞ぐように前記所定部位に相当する位
置内に内周面および外周面がメタライズ層を介してロウ
付けされたサファイアまたは石英からなる筒状の第二の
絶縁性部材とを具備したマイクロ波管用高周波窓であっ
て、前記第一の絶縁性部材は、その厚さが太さの４分の
１以上２分の１未満であり、外周面の前記メタライズ層
の上下端が前記第二の絶縁性部材の内周面のメタライズ
層の上下端より上下方向にそれぞれ前記第二の絶縁性部
材の軸方向の長さの４分の１以上突出し、かつ前記外周
面の前記メタライズ層の軸方向の長さが前記第二の絶縁
性部材の軸方向の長さの３倍以下であることを特徴とす
る。
【０００９】本発明は、上記の構成により、中心電極と
第一の絶縁性部材とのロウ付け部と、中心電極と第二の
絶縁性部材とのロウ付け部との熱応力バランスが良好と
なり、第一，第二の絶縁性部材の割れが防止できる。ま
た、第二の絶縁性部材の内周面の上下端に面取り加工を
施すことなくロウ付けしたことで、第二の絶縁性部材の
内周面に形成されたメタライズ層におけるマイクロ波の
反射によるマイクロ波透過ロスが防止でき、マイクロ波
の入出力特性が向上する。さらに、熱応力バランスが良
好になったことから、中心電極の機械的強度が向上し、
中心電極とマイクロ波発振器側の電極との接合時および
中心電極と外部導波管側の電極との接合時に第一の絶縁
性部材にクラックが発生するのを防止でき、製造の信頼
性が向上する。
【００１０】
【発明の実施の形態】本発明のマイクロ波管用高周波窓
について以下に詳細に説明する。図１は、本発明のマイ
クロ波管用高周波窓について実施の形態の一例を示す断
面図である。図１において、１１は円筒状等の筒状の外
周電極であり、真空中で溶解し溶融材料中に酸素を含ま
ないようにして製造された純度の高い無酸素銅（Ｃｕ）
から成り、内径寸法精度の高い加工が施されている。１
２は、円筒状等の筒状の中心電極であり、外周電極１１
と同様に無酸素銅（Ｃｕ）から成り、内径および外径と
も寸法精度の高い仕上げ加工が施されている。純度の高
い無酸素銅（Ｃｕ）を使用する理由としては、ロウ付け
接合炉の雰囲気中の水素と銅材料中の結晶粒界に含まれ
る酸素が結合し、水（Ｈ2Ｏ）の気孔が発生して脆化す
るため気密封止してロウ付けするのが困難になるためで
ある。
【００１１】第一の絶縁性部材１３はアルミナ（Ａｌ2
Ｏ3）セラミックス等から成り、第二の絶縁性部材１４
はサファイアまたは石英から成る。サファイアを用いる
ことにより、マイクロ波導入時に発生する熱損失を低減
することができるという効果が得られる。また、石英は
透明なため外部より製品の欠陥等を検知することが容易
であるとともに、硬質で絶縁性を有し、比較的低コスト
で使用できるという点で有利である。
【００１２】第一の絶縁性部材１３は、例えばアルミナ
セラミックスから成る場合、酸化アルミニウム（アルミ
ナ：Ａｌ2Ｏ3）、酸化珪素（ＳｉＯ2）、酸化カルシウ
ム（ＣａＯ）、酸化マグネシウム（ＭｇＯ）等の原料粉
末に適当な有機バインダを添加して作製した原料粉末の
泥漿を、所定形状のプレス型内に充填するとともに、こ
れを所定圧力でプレスして成形し、しかる後得られた成
形体を大気中にて約１６００℃の温度で焼成することに
より製作される。
【００１３】また第二の絶縁性部材１４は、例えばサフ
ァイアから成る場合、高純度アルミナ９９．９％（Ａｌ
2Ｏ3）を約２０００℃以上の高温でルツボの中で溶融
し、スリット加工が施されたＭｏ金属の金型を溶融面に
漬け、表面張力によりサファイアリボンを引き上げアル
ミナの単結晶成長させるＥＦＧ（Edge−defined Film−
fed Growth）法等により製作される。
【００１４】第一の絶縁性部材１３の外周面に形成され
たメタライズ層１５ａ、第二の絶縁性部材１４の内周面
に形成されたメタライズ層１５ｂ、および第二の絶縁性
部材１４の外周面に形成されたメタライズ層１５ｃは、
Ｍｏ−Ｍｎ等のメタライズ層から成り、これらのメタラ
イズ層１５ａ〜１５ｃは、第一の絶縁性部材１３を中心
電極１２に、第二の絶縁性部材１４を中心電極１２およ
び外周電極１１に接合するための下地金属層である。こ
れらのメタライズ層１５ａ〜１５ｃに、外周電極１１お
よび中心電極１２が銀（約７２重量％）−銅（約２８重
量％）合金から成るロウ材１７を介して接合される。
【００１５】メタライズ層１５ａ〜１５ｃは、例えばＭ
ｏ粉末，Ｍｎ粉末および金属の酸化物粉末に、適当な有
機バインダおよび溶剤を添加混合して得た金属ペースト
を、第一の絶縁性部材１３の外周面および絶縁性部材１
４の内外周面に筆塗り法等で塗布し、これを還元雰囲気
中で約１４００℃の温度で焼成することによって、第一
の絶縁性部材１３の外周面および第二の絶縁性部材１４
の内外周面に被着される。また、メタライズ層１５ａ〜
１５ｃの表面には、ロウ材との濡れ性に優れるＮｉ等の
金属をメッキ法により１〜１０μｍ程度の厚みに被着さ
せて成る金属メッキ層１６が形成されている。
【００１６】本発明において、第一の絶縁性部材１３
は、その厚さが太さの４分の１以上２分の１未満であ
る。第一の絶縁性部材１３の厚さが太さの４分の１未満
では、第二の絶縁性部材１４と中心電極１２の熱膨張係
数の相違に起因する中心電極１２の外周面側の引っ張り
応力と、中心電極１２の内周面側の引っ張り応力とのバ
ランスを取ることができなくなる。即ち、中心電極１２
の外周面側の応力と内周面側の応力との差が発生する。
その結果、第二の絶縁性部材１４と中心電極１２とのロ
ウ付けの際に、ロウ付け工程の降温工程において中心電
極１２の中心軸へ向かう径方向での熱収縮によって、第
二の絶縁性部材１４が中心電極１２から引き剥がされる
ように応力がはたらき、第二の絶縁性部材１４にクラッ
クが発生し易くなる。
【００１７】また、第一の絶縁性部材１３の厚さが太さ
の２分の１以上の場合、第一の絶縁性部材１３の軸方向
のガス抜き用の貫通孔が塞がってしまう。つまり、第一
の絶縁性部材１３が貫通孔のない中実のものとなる。こ
の場合、外部導波管Ｍ側の電極Ｏと中心電極１２とを溶
接で接合した際に、これらと第一の絶縁性部材１３で囲
まれる閉じた空間内に溶接で使用されるガスが封じ込め
られてしまう。その結果、溶接後に金属部材の付着物等
を除去する目的で行われる２００℃〜３５０℃程度の加
熱によって、封じ込まれたガスが熱膨張することにより
第一の絶縁性部材１３に大きな圧力がかかり、ロウ付け
部にクラック等を発生させる。
【００１８】第一の絶縁性部材１３は、外周面のメタラ
イズ層１５ａの上下端が第二の絶縁性部材１４の内周面
のメタライズ層１５ｂの上下端より上下方向にそれぞれ
第二の絶縁性部材１４の軸方向の長さの４分の１以上突
出し、かつ外周面のメタライズ層１５ａの軸方向の長さ
が第二の絶縁性部材１４の軸方向の長さの３倍以下であ
る。
【００１９】メタライズ層１５ａの上下端がメタライズ
層１５ｂの上下端より上下方向にそれぞれ第二の絶縁性
部材１４の軸方向の長さの４分の１以上突出していない
場合、上述したように、中心電極１２の外周面側の応力
と内周面側の応力との差が発生する。その結果、第二の
絶縁性部材１４と中心電極１２とのロウ付けの際に、ロ
ウ付け工程の降温工程において中心電極１２の中心軸へ
向かう径方向での熱収縮によって、第二の絶縁性部材１
４が中心電極１２から引き剥がされるように応力がはた
らき、絶縁性部材１４にクラックが発生し易くなる。
【００２０】また、第一の絶縁性部材１３の外周面のメ
タライズ層１５ａの軸方向の長さが第二の絶縁性部材１
４の軸方向の長さの３倍を超えると、中心電極１２の軸
方向の熱収縮による応力が増加して、第一の絶縁性部材
１３と中心電極１２のロウ付け部の端に軸方向の引っ張
りの応力が働き、第一の絶縁性部材１３の接合部からク
ラックが生じ、電極Ｎおよび電極Ｏの溶接時の熱処理に
よってクラックが進行して、最悪の場合第一の絶縁性部
材１３の脱落が発生する。
【００２１】中心電極１２および外周電極１１のそれぞ
れの厚さは０．５〜１．５ｍｍがよく、０．５ｍｍ未満
では、マイクロ波管用高周波窓の強度が不足し、１．５
ｍｍを超えると、応力によって第一，第二の絶縁性部材
１３，１４に割れやクラックが発生し易くなる。
【００２２】かくして、本発明においては、第二の絶縁
性部材１４の内周面の端に面取り部がないため、その内
周面に形成されたメタライズ層１５ｂの端部でマイクロ
波の反射が発生せず、マイクロ波透過ロスが小さくな
る。
【００２３】尚、本発明は上記の実施の形態に限定され
るものではなく、本発明の要旨を逸脱しない範囲内で種
々の変更を行なうことは何ら差し支えない。
【００２４】
【発明の効果】本発明は、第一の絶縁性部材は、その厚
さが太さの４分の１以上２分の１未満であり、外周面の
メタライズ層の上下端が第二の絶縁性部材の内周面のメ
タライズ層の上下端より上下方向にそれぞれ第二の絶縁
性部材の軸方向の長さの４分の１以上突出し、かつ外周
面のメタライズ層の軸方向の長さが第二の絶縁性部材の
軸方向の長さの３倍以下であることにより、中心電極と
第一の絶縁性部材とのロウ付け部と、中心電極と第二の
絶縁性部材とのロウ付け部との熱応力バランスが良好と
なり、第一，第二の絶縁性部材の割れが防止できる。
【００２５】また、第二の絶縁性部材の内周面の上下端
に面取り加工を施すことなくロウ付けしたことで、第二
の絶縁性部材の内周面に形成されたメタライズ層におけ
るマイクロ波の反射によるマイクロ波透過ロスが防止で
き、マイクロ波の入出力特性が向上する。
【００２６】さらに、熱応力バランスが良好になったこ
とから、中心電極の機械的強度が向上し、中心電極とマ
イクロ波発振器側の電極との接合時および中心電極と外
部導波管側の電極との接合時に、第一の絶縁性部材にク
ラックが発生するのを防止でき、製造の信頼性が向上す
る。
【００２７】また、第二の絶縁性部材がサファイアまた
は石英から成ることにより、サファイアの場合マイクロ
波導入時に発生する熱損失を低減することができ、また
石英の場合透明なため外部より製品の欠陥等を検知する
ことが容易であるとともに、硬質で絶縁性を有し、比較
的低コストで使用できるという効果が得られる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave waveguide such as a traveling wave tube and a klystron, and an apparatus using microwave power of a microwave waveguide. The present invention relates to a high-frequency window for a microwave tube, which is connected between a portion and an external waveguide with vacuum tightness. 2. Description of the Related Art A conventional high frequency window for a microwave tube is shown in FIG.
As shown in the cross-sectional view, one end is connected to a vacuum vessel L on the microwave oscillator side, the other end is joined to an external waveguide M by welding or the like, and a cylindrical outer peripheral electrode 1 is hermetically sealed. An electrode N on the microwave oscillator side is provided with a cylindrical central electrode 2 whose other end is joined to an electrode O on the external waveguide M side by welding or the like and hermetically sealed. Further, a cylindrical insulating member 4 made of alumina (Al 2 O 3 ) ceramics or the like is provided so as to close the gap between the outer peripheral electrode 1 and the center electrode 2. This insulating member 4
Has a chamfered portion C formed from the upper surface and the lower surface to the inner peripheral surface, and a metallized layer 5 made of molybdenum-manganese (Mo-Mn) or the like is formed on the outer peripheral surface, the inner peripheral surface, and the chamfered portion C of the insulating member 4. Has been adhered. Then, the outer peripheral surface is brazed to the outer peripheral electrode 1 and the inner peripheral surface is brazed to the center electrode 2 by the brazing material 6. The coefficient of thermal expansion of the insulating member 4 is about 8 × 10 -6.
/ ° C (room temperature to 800 ° C), and the thermal expansion coefficient of the center electrode 2 made of oxygen-free copper is about 20 × 10 −6 / ° C (room temperature to 80 ° C).
0 ° C.), which is a great difference, so that a tensile stress due to the heat shrinkage of the center electrode 2 is generated in the brazing portion of the insulating member 4 in the temperature lowering process of the brazing process. And
By forming and chamfering the chamfered portions C at the upper and lower ends of the inner peripheral surface of the insulating member 4, a meniscus of the brazing material 6 can be formed to relieve stress. For this reason, it is possible to effectively prevent the occurrence of cracks in the brazed portion of the insulating member 4. [0005] In this manner, the vacuum vessel L of the microwave oscillator is hermetically sealed, and the microwave generated by the microwave oscillator can be transmitted through the insulating member 4 and introduced into the external waveguide M. It becomes a high-frequency window for microwave tubes. [0006] However, since there is a chamfered portion C on the inner peripheral surface of the insulating member 4 through which the microwave is transmitted, the metallized layer 5 is adhered. There was a problem that microwaves were reflected by the layer 5 to cause transmission loss, and high-frequency characteristics deteriorated. Therefore, the present invention has been completed in view of the above-mentioned problems in the prior art, and an object of the present invention is to effectively prevent the occurrence of cracks without chamfering the inner peripheral surface of the insulating member. Another object of the present invention is to provide a highly reliable microwave tube high-frequency window having improved microwave transmission characteristics. A high frequency window for a microwave tube according to the present invention comprises a cylindrical outer electrode, a cylindrical center electrode disposed concentrically inside the outer electrode, and a center electrode. A cylindrical first insulating member having an outer peripheral surface brazed to a predetermined portion on the inner surface of the electrode via a metallization layer, and corresponds to the predetermined portion so as to close a gap between the outer peripheral electrode and the center electrode; And a cylindrical second insulating member made of sapphire or quartz having an inner peripheral surface and an outer peripheral surface brazed through a metallization layer in a position where The thickness of the insulating member is not less than ４ and less than の of the thickness, and the upper and lower ends of the metallized layer on the outer peripheral surface are metallized layers on the inner peripheral surface of the second insulating member. Of the second insulating member in the vertical direction from the upper and lower ends, respectively. An axial length of the metallized layer protrudes at least one-fourth of the axial length, and the axial length of the metallized layer on the outer peripheral surface is three times or less the axial length of the second insulating member. And According to the present invention, the thermal stress balance between the brazed portion between the center electrode and the first insulating member and the brazed portion between the center electrode and the second insulating member can be improved. In addition, cracking of the first and second insulating members can be prevented. In addition, by brazing the upper and lower ends of the inner peripheral surface of the second insulating member without performing chamfering, reflection of microwaves on the metallized layer formed on the inner peripheral surface of the second insulating member Microwave transmission loss can be prevented, and microwave input / output characteristics are improved. Furthermore, since the thermal stress balance is improved, the mechanical strength of the center electrode is improved,
When the center electrode is joined to the electrode on the microwave oscillator side and when the center electrode is joined to the electrode on the external waveguide side, cracks can be prevented from occurring in the first insulating member, improving the reliability of production. I do. DETAILED DESCRIPTION OF THE INVENTION The high frequency window for a microwave tube according to the present invention will be described in detail below. FIG. 1 is a cross-sectional view showing an example of an embodiment of a high-frequency window for a microwave tube according to the present invention. In FIG. 1, reference numeral 11 denotes a cylindrical outer electrode such as a cylindrical shape, which is a high-purity oxygen-free copper (Cu) manufactured by melting in a vacuum and containing no oxygen in a molten material.
And is processed with high internal diameter dimensional accuracy. 1
Reference numeral 2 denotes a cylindrical center electrode such as a cylindrical shape, and an outer peripheral electrode 11.
As in the case of the above, it is made of oxygen-free copper (Cu), and both the inner diameter and the outer diameter are finished with high dimensional accuracy. The reason for using high-purity oxygen-free copper (Cu) is that hydrogen contained in the atmosphere of the brazing furnace and oxygen contained in the crystal grain boundaries in the copper material are combined to form pores of water (H 2 O). This is because it occurs and becomes brittle, making it difficult to hermetically seal and braze. The first insulating member 13 is made of alumina (Al 2
O 3 ) The second insulating member 14 made of ceramics or the like
Consists of sapphire or quartz. The use of sapphire has the effect of reducing the heat loss generated when microwaves are introduced. In addition, quartz is advantageous in that it is transparent so that it is easy to detect a defect or the like of a product from the outside, and that it is hard and has insulating properties and can be used at a relatively low cost. When the first insulating member 13 is made of, for example, alumina ceramic, the first insulating member 13 is made of aluminum oxide (alumina: Al 2 O 3 ), silicon oxide (SiO 2 ), calcium oxide (CaO), magnesium oxide (MgO), or the like. The slurry of the raw material powder prepared by adding an appropriate organic binder to the raw material powder is filled into a press die having a predetermined shape, and the resultant is pressed at a predetermined pressure and molded. It is manufactured by firing at a temperature of about 1600 ° C. in the inside. When the second insulating member 14 is made of, for example, sapphire, high-purity alumina 99.9% (Al
EFG that melts 2 O 3 ) in a crucible at a high temperature of about 2000 ° C. or higher, dipping a slit-processed Mo metal mold into a molten surface, pulls up a sapphire ribbon by surface tension, and grows a single crystal of alumina (Edge-defined Film-
fed Growth) method. The metallized layer 15a formed on the outer peripheral surface of the first insulating member 13, the metallized layer 15b formed on the inner peripheral surface of the second insulating member 14, and the outer periphery of the second insulating member 14 The metallized layer 15c formed on the surface
The metallized layers 15a to 15c join the first insulating member 13 to the center electrode 12 and the second insulating member 14 to the center electrode 12 and the outer peripheral electrode 11. Metal layer for the purpose. The outer electrode 11 and the center electrode 12 are bonded to these metallized layers 15a to 15c via a brazing material 17 made of a silver (about 72% by weight) -copper (about 28% by weight) alloy. The metallized layers 15a to 15c are made of, for example, M
A metal paste obtained by adding an appropriate organic binder and a solvent to o powder, Mn powder and a metal oxide powder is mixed with the outer peripheral surface of the first insulating member 13 and the insulating member 1.
The inner and outer peripheral surfaces of the first insulating member 13 and the second insulating member 14 are applied to the inner and outer peripheral surfaces of the first insulating member 13 by brushing at a temperature of about 1400 ° C. in a reducing atmosphere.
Is attached to the inner and outer peripheral surfaces of the. In addition, the metallized layers 15a to 15a
On the surface of 15c, a metal plating layer 16 formed by applying a metal such as Ni having excellent wettability with a brazing material to a thickness of about 1 to 10 μm by a plating method is formed. In the present invention, the first insulating member 13
Has a thickness of not less than ４ and less than の of the thickness. If the thickness of the first insulating member 13 is less than one-fourth of the thickness, the outer peripheral surface of the center electrode 12 is pulled by the difference in the thermal expansion coefficient between the second insulating member 14 and the center electrode 12. It becomes impossible to balance the stress with the tensile stress on the inner peripheral surface side of the center electrode 12. That is, the center electrode 12
A difference occurs between the stress on the outer peripheral surface side and the stress on the inner peripheral surface side.
As a result, when the second insulating member 14 and the center electrode 12 are brazed, the second insulating member 14 is thermally shrunk in the radial direction toward the center axis of the center electrode 12 in the temperature lowering step of the brazing step. Stress acts so that the member 14 is peeled off from the center electrode 12, and cracks are easily generated in the second insulating member 14. When the thickness of the first insulating member 13 is more than half the thickness, the through hole for venting gas in the axial direction of the first insulating member 13 is closed. That is, the first insulating member 13 is a solid member having no through hole. In this case, when the electrode O on the outer waveguide M side and the center electrode 12 are joined by welding, the gas used for welding is confined in a closed space surrounded by these and the first insulating member 13. Will be done. As a result, the enclosed gas thermally expands due to heating at about 200 ° C. to 350 ° C. performed for the purpose of removing deposits and the like on the metal member after welding, so that a large pressure is applied to the first insulating member 13. As a result, cracks and the like are generated in the brazing portion. The upper and lower ends of the metallized layer 15a on the outer peripheral surface of the first insulating member 13 are vertically separated from the upper and lower ends of the metallized layer 15b on the inner peripheral surface of the second insulating member 14, respectively. The axial length of the metallized layer 15a on the outer peripheral surface is three times or less the axial length of the second insulating member 14, which is one fourth or more of the axial length of the member 14. If the upper and lower ends of the metallized layer 15a do not project upward and downward from the upper and lower ends of the metallized layer 15b by more than one-fourth of the axial length of the second insulating member 14, respectively, as described above, A difference occurs between the stress on the outer peripheral surface side of the center electrode 12 and the stress on the inner peripheral surface side. As a result, when the second insulating member 14 and the center electrode 12 are brazed, the second insulating member 14 is thermally shrunk in the radial direction toward the center axis of the center electrode 12 in the temperature lowering step of the brazing step. Member 1
The stress acts so that the electrode 4 is peeled off from the center electrode 12, and cracks are easily generated in the insulating member 14. The axial length of the metallized layer 15a on the outer peripheral surface of the first insulating member 13 is equal to that of the second insulating member 1.
When the axial length exceeds three times the axial length, the stress due to the axial thermal shrinkage of the center electrode 12 increases, and the first insulating member 13 and the end of the brazed portion of the central electrode 12 , A crack is generated from the joint of the first insulating member 13, and the crack progresses due to heat treatment at the time of welding the electrode N and the electrode O. In the worst case, the first insulating member 13 Dropout occurs. The thickness of each of the center electrode 12 and the outer peripheral electrode 11 is preferably 0.5 to 1.5 mm.
If it exceeds mm, cracks and cracks tend to occur in the first and second insulating members 13 and 14 due to stress. Thus, in the present invention, since there is no chamfer at the end of the inner peripheral surface of the second insulating member 14, the reflection of the microwave is not reflected at the end of the metallized layer 15b formed on the inner peripheral surface. No microwave transmission loss occurs. It should be noted that the present invention is not limited to the above-described embodiment, and that various changes may be made without departing from the spirit of the present invention. According to the present invention, the first insulating member has a thickness of not less than one-fourth and less than one-half the thickness, and the upper and lower ends of the metallized layer on the outer peripheral surface are the same. The upper and lower ends of the metallized layer on the inner peripheral surface of the second insulating member vertically project from the upper and lower ends, respectively, by a quarter or more of the axial length of the second insulating member. Since the length is three times or less the axial length of the second insulating member, the brazing portion between the center electrode and the first insulating member, and the center electrode and the second insulating member And the thermal stress balance with the brazing portion is improved, and cracking of the first and second insulating members can be prevented. Further, by brazing the upper and lower ends of the inner peripheral surface of the second insulating member without performing chamfering, the microwave in the metallized layer formed on the inner peripheral surface of the second insulating member is formed. The microwave transmission loss due to the reflection of light can be prevented, and the microwave input / output characteristics are improved. Further, since the thermal stress balance is improved, the mechanical strength of the center electrode is improved, and the center electrode is joined to the microwave oscillator side electrode and the center electrode is connected to the external waveguide side electrode. At the time of joining, the first insulating member can be prevented from cracking, and the manufacturing reliability is improved. Further, since the second insulating member is made of sapphire or quartz, the heat loss generated when microwaves are introduced can be reduced in the case of sapphire, and in the case of quartz, since the quartz is transparent, defects in the product from the outside can be reduced. And the like can be easily detected, and the effect is obtained that it is hard and has insulating properties and can be used at relatively low cost.
【図面の簡単な説明】
【図１】本発明のマイクロ波管用高周波窓について実施
の形態の一例を示す断面図である。
【図２】従来のマイクロ波管用高周波窓の一例を示す断
面図である。
【符号の説明】
１１：外周電極
１２：中心電極
１３：第一の絶縁性部材
１４：第二の絶縁性部材
１５ａ〜１５ｃ：メタライズ層
１６：金属メッキ層
１７：ロウ材
Ｌ：真空容器
Ｍ：外部導波管
Ｎ：電極
Ｏ：電極BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an example of an embodiment of a high-frequency window for a microwave tube according to the present invention. FIG. 2 is a cross-sectional view showing an example of a conventional high-frequency window for a microwave tube. [Description of Signs] 11: Outer peripheral electrode 12: Center electrode 13: First insulating member 14: Second insulating members 15a to 15c: Metallized layer 16: Metal plating layer 17: Brazing material L: Vacuum container M: External waveguide N: electrode O: electrode
Claims (1)
同心状に配置された筒状の中心電極と、該中心電極の内
側面の所定部位に外周面がメタライズ層を介してロウ付
けされた筒状の第一の絶縁性部材と、前記外周電極と前
記中心電極との間を塞ぐように前記所定部位に相当する
位置内に内周面および外周面がメタライズ層を介してロ
ウ付けされたサファイアまたは石英から成る筒状の第二
の絶縁性部材とを具備したマイクロ波管用高周波窓であ
って、前記第一の絶縁性部材は、その厚さが太さの４分
の１以上２分の１未満であり、外周面の前記メタライズ
層の上下端が前記第二の絶縁性部材の内周面のメタライ
ズ層の上下端より上下方向にそれぞれ前記第二の絶縁性
部材の軸方向の長さの４分の１以上突出し、かつ前記外
周面の前記メタライズ層の軸方向の長さが前記第二の絶
縁性部材の軸方向の長さの３倍以下であることを特徴と
するマイクロ波管用高周波窓。Claims: 1. A cylindrical outer peripheral electrode, a cylindrical central electrode disposed concentrically inside the outer peripheral electrode, and an outer peripheral surface at a predetermined position on an inner side surface of the central electrode. A cylindrical first insulating member brazed via a metallization layer, and an inner peripheral surface and an outer peripheral surface in a position corresponding to the predetermined portion so as to close a gap between the outer peripheral electrode and the center electrode. A high-frequency window for a microwave tube, comprising: a cylindrical second insulating member made of sapphire or quartz brazed through a metallization layer, wherein the first insulating member has a large thickness. And the upper and lower ends of the metallized layer on the outer peripheral surface are vertically separated from the upper and lower ends of the metallized layer on the inner peripheral surface of the second insulating member. Projecting at least a quarter of the axial length of the insulating member, and Axial direction of the length the second insulating axial microwave tube for high frequency windows, characterized in that at most 3 times the length of members of the metallized layer of the peripheral surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001330252A JP2003133802A (en) | 2001-10-29 | 2001-10-29 | High frequency window for microwave tube |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001330252A JP2003133802A (en) | 2001-10-29 | 2001-10-29 | High frequency window for microwave tube |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003133802A true JP2003133802A (en) | 2003-05-09 |
Family
ID=19146002
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001330252A Pending JP2003133802A (en) | 2001-10-29 | 2001-10-29 | High frequency window for microwave tube |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2003133802A (en) |
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|---|---|---|---|---|
| US9154678B2 (en) | 2013-12-11 | 2015-10-06 | Apple Inc. | Cover glass arrangement for an electronic device |
| US9221289B2 (en) | 2012-07-27 | 2015-12-29 | Apple Inc. | Sapphire window |
| US9225056B2 (en) | 2014-02-12 | 2015-12-29 | Apple Inc. | Antenna on sapphire structure |
| US9232672B2 (en) | 2013-01-10 | 2016-01-05 | Apple Inc. | Ceramic insert control mechanism |
| US9632537B2 (en) | 2013-09-23 | 2017-04-25 | Apple Inc. | Electronic component embedded in ceramic material |
| US9678540B2 (en) | 2013-09-23 | 2017-06-13 | Apple Inc. | Electronic component embedded in ceramic material |
| US10052848B2 (en) | 2012-03-06 | 2018-08-21 | Apple Inc. | Sapphire laminates |
| US10406634B2 (en) | 2015-07-01 | 2019-09-10 | Apple Inc. | Enhancing strength in laser cutting of ceramic components |
-
2001
- 2001-10-29 JP JP2001330252A patent/JP2003133802A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10052848B2 (en) | 2012-03-06 | 2018-08-21 | Apple Inc. | Sapphire laminates |
| US9221289B2 (en) | 2012-07-27 | 2015-12-29 | Apple Inc. | Sapphire window |
| US9232672B2 (en) | 2013-01-10 | 2016-01-05 | Apple Inc. | Ceramic insert control mechanism |
| US9632537B2 (en) | 2013-09-23 | 2017-04-25 | Apple Inc. | Electronic component embedded in ceramic material |
| US9678540B2 (en) | 2013-09-23 | 2017-06-13 | Apple Inc. | Electronic component embedded in ceramic material |
| US9154678B2 (en) | 2013-12-11 | 2015-10-06 | Apple Inc. | Cover glass arrangement for an electronic device |
| US10324496B2 (en) | 2013-12-11 | 2019-06-18 | Apple Inc. | Cover glass arrangement for an electronic device |
| US10386889B2 (en) | 2013-12-11 | 2019-08-20 | Apple Inc. | Cover glass for an electronic device |
| US9225056B2 (en) | 2014-02-12 | 2015-12-29 | Apple Inc. | Antenna on sapphire structure |
| US9461357B2 (en) | 2014-02-12 | 2016-10-04 | Apple Inc. | Antenna on sapphire structure |
| US9692113B2 (en) | 2014-02-12 | 2017-06-27 | Apple Inc. | Antenna on sapphire structure |
| US10406634B2 (en) | 2015-07-01 | 2019-09-10 | Apple Inc. | Enhancing strength in laser cutting of ceramic components |
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