JPH05242950A - Sealed electrode and surge absorber therewith - Google Patents
Sealed electrode and surge absorber therewithInfo
- Publication number
- JPH05242950A JPH05242950A JP7635692A JP7635692A JPH05242950A JP H05242950 A JPH05242950 A JP H05242950A JP 7635692 A JP7635692 A JP 7635692A JP 7635692 A JP7635692 A JP 7635692A JP H05242950 A JPH05242950 A JP H05242950A
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- glass tube
- sealing
- sealed
- thin film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Thermistors And Varistors (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はガラス管に封着される封
止電極及びこれを用いたサージアブソーバに関する。更
に詳しくはマイクロギャップ式サージ吸収素子をガラス
管内にハーメチックシール（hermetic seal）したサー
ジアブソーバに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing electrode sealed to a glass tube and a surge absorber using the sealing electrode. More specifically, it relates to a surge absorber in which a micro gap type surge absorbing element is hermetically sealed in a glass tube.
【０００２】[0002]
【従来の技術】この種のサージアブソーバは、電話機、
ファクシミリ、電話交換機、モデム等の通信機器の電子
部品を雷サージから保護するために使用される。このサ
ージアブソーバは、マイクロギャップ式サージ吸収素子
を収容したガラス管の両端に封止電極を取付け、ガラス
管内に希ガス、窒素ガス等の不活性ガスを封入した後、
カーボンヒータのような加熱装置で高温度で加熱して封
止電極をガラス管に封着して作られる。一般に封止電極
は、封着時のガラス管の熱収縮によるクラックの発生を
防止するためにその素体にガラスと熱膨張係数のほぼ等
しい金属を用い、しかも封着時のガラスに対する濡れ性
を良くするためにガラス管と接触する部分の素体表面に
酸化膜を設けている。封止電極を高温で加熱すると電極
素体である金属が酸化膜を介してガラスになじみ、封止
電極が封着されてガラス管内を気密にする。従来、封止
電極の素体には鉄−ニッケル合金、鉄−ニッケル−クロ
ム合金、ジュメット線（Dumet wire）等が多用されてい
る。2. Description of the Related Art This type of surge absorber is used for telephones,
Used to protect electronic components of communication equipment such as facsimiles, telephone exchanges, and modems from lightning surges. This surge absorber has sealing electrodes attached to both ends of a glass tube containing a microgap type surge absorbing element, and a rare gas, an inert gas such as nitrogen gas is sealed in the glass tube,
It is made by heating at a high temperature with a heating device such as a carbon heater and sealing the sealed electrode in a glass tube. In general, a sealing electrode uses a metal whose coefficient of thermal expansion is almost equal to that of glass in its element body in order to prevent the occurrence of cracks due to thermal contraction of the glass tube during sealing, and further, the wettability to glass during sealing is ensured. An oxide film is provided on the surface of the element body in contact with the glass tube to improve the quality. When the sealed electrode is heated at a high temperature, the metal that is the electrode body fits into the glass through the oxide film, and the sealed electrode is sealed to make the inside of the glass tube airtight. Conventionally, iron-nickel alloys, iron-nickel-chromium alloys, Dumet wires, and the like have been widely used as the body of the sealing electrode.
【０００３】[0003]
【発明が解決しようとする課題】鉄−ニッケル合金は比
較的容易に酸化されるため、予め酸化膜を形成してから
封着した場合には封着時の酸化作用も加わって膜厚が大
きくなり、酸化膜の鉄−ニッケル合金に対する付着強度
が低下し易い。これを回避するため鉄−ニッケル合金を
封止電極の素体にする場合には、素体のままガラス管に
取付け、ガスバーナの炎等により酸化膜を形成しながら
封止電極を封着している。この結果、鉄−ニッケル合金
は不活性ガス雰囲気中のカーボンヒータの加熱により封
着されるサージアブソーバの封止電極には適しない。鉄
−ニッケル−クロム合金は鉄−ニッケル合金と異なり、
予め酸化膜を形成してから封着しても適度の膜厚になる
ため、合金に対するその付着強度は低下しない。しかし
この酸化膜中のＣｒ2Ｏ3はガラスに対する濡れ性に劣る
ため、封着温度を非常に高くしないと良好な封着効果が
得られない。ジュメット線は鉄−ニッケル合金の表面を
銅で被覆した線であるため、サージアブソーバの封止電
極に適した形状に加工することが困難である上、低仕事
関数の電子放射促進物質をガラス管内部に向けて設ける
ことが極めて難しい。またガラス管に封着した後で、こ
れらの材料で作られた封止電極の外面にリード線を接続
する場合、酸化膜を塩酸で除去してからはんだ付けを行
っているが、従来の酸化膜は塩酸で容易に除去すること
ができない。Since the iron-nickel alloy is relatively easily oxidized, when the oxide film is formed in advance and then sealed, the oxidation action at the time of sealing is also added to increase the film thickness. Therefore, the adhesion strength of the oxide film to the iron-nickel alloy is likely to decrease. To avoid this, when using an iron-nickel alloy as the body of the sealing electrode, attach the body as it is to a glass tube and seal the sealing electrode while forming an oxide film by the flame of a gas burner or the like. There is. As a result, the iron-nickel alloy is not suitable for the sealing electrode of the surge absorber that is sealed by heating the carbon heater in the inert gas atmosphere. Iron-nickel-chromium alloy is different from iron-nickel alloy
Even if the oxide film is formed in advance and then the film is sealed, the film has an appropriate film thickness, and therefore the adhesive strength to the alloy does not decrease. However, since Cr 2 O 3 in this oxide film is inferior in wettability to glass, a good sealing effect cannot be obtained unless the sealing temperature is made extremely high. Since the Dumet wire is a wire in which the surface of an iron-nickel alloy is coated with copper, it is difficult to process it into a shape suitable for the sealing electrode of a surge absorber, and a glass tube containing an electron emission promoting substance with a low work function is used. It is extremely difficult to install it inside. In addition, when connecting the lead wire to the outer surface of the sealing electrode made of these materials after sealing the glass tube, the oxide film is removed with hydrochloric acid before soldering. The membrane cannot be easily removed with hydrochloric acid.
【０００４】一方、従来のマイクロギャップ式サージ吸
収素子をガラス管内に気密に収容したサージアブソーバ
では、封止電極に電子放射促進作用がないため、動作時
のアーク放電がセラミックス素体表面の導電性皮膜及び
マイクロギャップ上を通過した後、封止電極まで達しに
くい。このためマイクロギャップの近傍でアーク放電が
形成される時間が長くなり、アーク放電により導電性皮
膜及びマイクロギャップが劣化して、サージアブソーバ
の特性に悪影響を与えている。On the other hand, in the surge absorber in which the conventional microgap type surge absorbing element is hermetically housed in the glass tube, since the sealing electrode has no electron emission promoting action, the arc discharge during operation is electrically conductive on the surface of the ceramic body. After passing over the film and the microgap, it is difficult to reach the sealing electrode. For this reason, the time during which arc discharge is formed in the vicinity of the micro gap becomes long, and the conductive coating and the micro gap are deteriorated by the arc discharge, which adversely affects the characteristics of the surge absorber.
【０００５】本発明の目的は、不活性ガス雰囲気中で封
着でき、ガラス管への封着性が良く、しかも電子放射促
進作用のある封止電極を提供することにある。本発明の
別の目的は、リード線を容易にはんだ付けできる封止電
極を提供することにある。また本発明の更に別の目的
は、封着時及びアーク放電時の導電性皮膜及びマイクロ
ギャップが劣化しにくく、サージ耐量が高く、寿命の長
いサージアブソーバを提供することにある。An object of the present invention is to provide a sealed electrode which can be sealed in an inert gas atmosphere, has a good sealing property to a glass tube, and has an electron emission promoting action. Another object of the present invention is to provide a sealed electrode to which a lead wire can be easily soldered. Still another object of the present invention is to provide a surge absorber which is resistant to deterioration of the conductive film and the microgap at the time of sealing and arc discharge, has a high surge resistance and has a long life.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
に、本発明のガラス管に封着される封止電極は、図１に
示すように、鉄及びニッケルを含む合金からなる電極素
体１１ａと、電極素体１１ａを被包するように形成され
た所定の厚さの銅薄膜１１ｂと、ガラス管１０の内部に
面する銅薄膜１１ｂの表面に形成されたＣｕ2Ｏ膜１１
ｃとを備えたものである。また本発明のサージアブソー
バは、ガラス管１０と、このガラス管１０内に収容さ
れ、導電性皮膜１３ａで被包した円柱状のセラミックス
素体１３ｂの周面にマイクロギャップ１３ｃが形成さ
れ、セラミックス素体１３ｂの両端に一対のキャップ電
極１３ｄを有するサージ吸収素子１３と、このガラス管
１０の両端に封着した状態でサージ吸収素子１３を固定
し、かつ一対のキャップ電極１３ｄに電気的に接続され
た前記封止電極１１，１２と、これらの封止電極１１，
１２とガラス管１０とにより形成される空間に封入され
た不活性ガス１４とを備えたものである。To achieve the above object, the sealing electrode sealed in the glass tube of the present invention is, as shown in FIG. 1, an electrode body made of an alloy containing iron and nickel. 11a, a copper thin film 11b having a predetermined thickness formed so as to cover the electrode body 11a, and a Cu 2 O film 11 formed on the surface of the copper thin film 11b facing the inside of the glass tube 10.
and c. The surge absorber according to the present invention has a glass tube 10 and a microgap 13c formed on the peripheral surface of a cylindrical ceramic body 13b housed in the glass tube 10 and covered with a conductive film 13a. The surge absorbing element 13 having a pair of cap electrodes 13d at both ends of the body 13b, and the surge absorbing element 13 fixed in a sealed state at both ends of the glass tube 10 and electrically connected to the pair of cap electrodes 13d. And the sealing electrodes 11 and 12,
12 and the inert gas 14 enclosed in the space formed by the glass tube 10.
【０００７】本発明のガラス管は、ホウケイ酸ガラスの
ような硬質ガラス、又は鉛ガラス、ソーダ石灰ガラスの
ような軟質ガラスから作られる。硬質ガラスより熱膨張
係数の大きな軟質ガラスにも適用することができる。ま
た電極素体は、鉄−ニッケル合金、鉄−ニッケル−クロ
ム合金、鉄−ニッケル−コバルト合金等の鉄とニッケル
を含む熱膨張係数がガラスより低い合金からなる。電極
素体は所定の形状に成形して作られる。電極素体の熱膨
張係数とガラス管の熱膨張係数とを整合させるために熱
膨張係数の大きな銅薄膜で電極素体を被包する。即ち、
電極素体の熱膨張係数とガラス管の熱膨張係数との差が
大きいときには銅薄膜の厚さを大きくし、その差が小さ
いときには銅薄膜の厚さを小さくする。銅薄膜は、必要
な厚さの程度に応じて、めっき、高周波スパッタリン
グ、真空蒸着等の薄膜形成技術により直接電極素体の表
面に形成される。銅薄膜の表面にはガラスに対する濡れ
性を良くし、かつ電子放射を促進する仕事関数の小さい
Ｃｕ2Ｏ膜が形成される。このＣｕ2Ｏ膜は銅薄膜を酸化
することにより容易に形成することができる。The glass tube of the present invention is made of hard glass such as borosilicate glass, or soft glass such as lead glass and soda lime glass. It can also be applied to soft glass having a larger coefficient of thermal expansion than hard glass. The electrode body is made of an alloy containing iron and nickel, such as an iron-nickel alloy, an iron-nickel-chromium alloy, and an iron-nickel-cobalt alloy, having a coefficient of thermal expansion lower than that of glass. The electrode body is formed by molding it into a predetermined shape. In order to match the coefficient of thermal expansion of the electrode body with the coefficient of thermal expansion of the glass tube, the electrode body is covered with a copper thin film having a large coefficient of thermal expansion. That is,
When the difference between the coefficient of thermal expansion of the electrode body and the coefficient of thermal expansion of the glass tube is large, the thickness of the copper thin film is increased, and when the difference is small, the thickness of the copper thin film is decreased. The copper thin film is directly formed on the surface of the electrode body by a thin film forming technique such as plating, high-frequency sputtering, or vacuum deposition, depending on the required thickness. On the surface of the copper thin film, a Cu 2 O film having a low work function which improves the wettability to glass and promotes electron emission is formed. This Cu 2 O film can be easily formed by oxidizing a copper thin film.
【０００８】[0008]
【作用】熱膨張係数が鉄及びニッケルを含む合金より大
きな銅をこの合金とガラスとの間に所定の厚さで介在さ
せることにより、鉄及びニッケルを含む合金の熱膨張係
数がガラスの熱膨張係数に近づき、封着時にガラス管の
熱収縮によるクラックの発生がなくなる。また、封止電
極の表面に銅薄膜とＣｕ2Ｏ膜の２つの層が形成される
ため、第一に封着時のガラスに対する濡れ性が良くなり
低温でしかも不活性ガス雰囲気中で封着でき、熱ストレ
スによる導電性皮膜及びマイクロギャップの劣化が起き
にくい。第二にＣｕ2Ｏは仕事関数が小さいため、その
電子放射促進作用によりアーク放電がサージ吸収素子の
導電性皮膜から離れた封止電極間に容易に移行し、放電
による導電性皮膜の熱損傷を解消する。更に、封着後封
止電極の外面にリード線を接続するために、封止電極外
面を塩酸で洗浄すると、封着により形成された銅薄膜上
の酸化膜（Ｃｕ2Ｏ膜）は簡単に除去されリード線を容
易にはんだ付けできる。[Function] By interposing copper having a coefficient of thermal expansion larger than that of the alloy containing iron and nickel in a predetermined thickness between the alloy and the glass, the coefficient of thermal expansion of the alloy containing iron and nickel is the thermal expansion of the glass. The coefficient is approached, and cracking due to heat shrinkage of the glass tube is eliminated during sealing. Also, since two layers, a copper thin film and a Cu 2 O film, are formed on the surface of the sealing electrode, firstly, the wettability to glass at the time of sealing is improved, and sealing is performed at a low temperature and in an inert gas atmosphere. It is possible to prevent deterioration of the conductive film and the micro gap due to heat stress. Secondly, since Cu 2 O has a small work function, the arc discharge easily moves between the sealing electrodes separated from the conductive film of the surge absorbing element due to its electron emission promoting action, and the conductive film is thermally damaged by the discharge. To eliminate. Further, when the outer surface of the sealing electrode is washed with hydrochloric acid to connect the lead wire to the outer surface of the sealing electrode after sealing, the oxide film (Cu 2 O film) on the copper thin film formed by sealing is easily formed. It is removed and the lead wire can be easily soldered.
【０００９】[0009]
【実施例】次に、本発明の実施例を図面に基づいて詳し
く説明する。 ＜実施例＞図１及び図２に示すように、円筒形のガラス
管１０の両端に封止電極１１，１２が封着される。図で
は上端の封止電極１１を詳細に示す。この例では、ガラ
ス管１０は軟質ガラスの一種の鉛ガラスである。また封
止電極１１は、鉄４２％とニッケル５８％の合金からな
る電極素体１１ａと、電極素体１１ａを被包するように
形成された所定の厚さの銅薄膜１１ｂと、銅薄膜１１ｂ
の表面に形成されたＣｕ2Ｏ膜１１ｃとにより構成され
る。電極素体１１ａをガラス管１０に挿入し得るように
ハット状に成形した後、電極素体１１ａ全体を銅めっき
して素体表面に銅薄膜１１ｂを所定の厚さに形成する。
次いで銅薄膜１１ｂの形成された電極素体１１ａを高温
の酸素雰囲気下に置き、その後急冷して銅薄膜１１ｂ表
面にＣｕ2Ｏ膜１１ｃを形成する。ガラス管１０内には
マイクロギャップ式のサージ吸収素子１３が収容され
る。このサージ吸収素子１３は導電性皮膜１３ａで被包
した円柱状のセラミックス素体１３ｂの周面に数１０μ
ｍのマイクロギャップ１３ｃをレーザにより形成させた
後、セラミックス素体の両端にキャップ電極１３ｄを圧
入して作られる。Embodiments of the present invention will now be described in detail with reference to the drawings. <Example> As shown in FIGS. 1 and 2, sealing electrodes 11 and 12 are sealed at both ends of a cylindrical glass tube 10. In the figure, the sealing electrode 11 at the upper end is shown in detail. In this example, the glass tube 10 is a kind of soft glass lead glass. The sealing electrode 11 includes an electrode body 11a made of an alloy of 42% iron and 58% nickel, a copper thin film 11b having a predetermined thickness formed so as to enclose the electrode body 11a, and a copper thin film 11b.
And a Cu 2 O film 11c formed on the surface of the. After forming the electrode body 11a into a hat shape so that it can be inserted into the glass tube 10, the entire electrode body 11a is plated with copper to form a copper thin film 11b on the surface of the body to a predetermined thickness.
Next, the electrode element body 11a on which the copper thin film 11b is formed is placed in a high temperature oxygen atmosphere and then rapidly cooled to form a Cu 2 O film 11c on the surface of the copper thin film 11b. A microgap type surge absorbing element 13 is housed in the glass tube 10. The surge absorbing element 13 has a cylindrical ceramic body 13b covered with a conductive film 13a and has a peripheral surface of several tens of μm.
After forming a microgap 13c of m by a laser, cap electrodes 13d are press-fitted to both ends of the ceramic body.
【００１０】またサージアブソーバ２０は次の方法によ
り作られる。先ずガラス管１０内にサージ吸収素子１３
を入れ、ガラス管１０の一端に封止電極１１を取付け
る。封止電極１１の凹部１１ｄをサージ吸収素子１３の
キャップ電極１３ｄに嵌合させる。次いでガラス管１０
の他端に封止電極１１と同一構造の封止電極１２を同様
に取付ける。これによりサージ吸収素子１３の一対のキ
ャップ電極１３ｄが封止電極１１，１２と電気的に接続
される。次にこの組立体をカーボンヒータを設けた封着
室（図示せず）に入れ、封着室を負圧にすることにより
ガラス管内部の空気を抜いた後、代わりに不活性ガス、
例えばアルゴンガスを封着室に供給してガラス管内にこ
のアルゴンガスを導入する。この状態でカーボンヒータ
によりガラス管１０及び封止電極１１，１２を加熱す
る。Ｃｕ2Ｏ膜を介して銅薄膜付き電極素体１１ａの周
縁がガラス管１０になじみ、封止電極１１がガラス管１
０に封着される。これによりアルゴンガス１４が封入さ
れたサージアブソーバ２０が作られる。Ｃｕ2Ｏ膜の存
在によりこの封止電極１１，１２は約７００℃の低温で
封着される。The surge absorber 20 is manufactured by the following method. First, the surge absorber 13 is placed in the glass tube 10.
Then, the sealing electrode 11 is attached to one end of the glass tube 10. The recess 11d of the sealing electrode 11 is fitted into the cap electrode 13d of the surge absorbing element 13. Then the glass tube 10
A sealing electrode 12 having the same structure as the sealing electrode 11 is similarly attached to the other end of the. As a result, the pair of cap electrodes 13d of the surge absorbing element 13 is electrically connected to the sealing electrodes 11 and 12. Next, this assembly is put in a sealing chamber (not shown) provided with a carbon heater, and the inside of the glass tube is evacuated by setting a negative pressure in the sealing chamber.
For example, argon gas is supplied to the sealing chamber and introduced into the glass tube. In this state, the glass tube 10 and the sealing electrodes 11 and 12 are heated by the carbon heater. The peripheral edge of the electrode body 11a with a copper thin film fits the glass tube 10 through the Cu 2 O film, and the sealing electrode 11 becomes the glass tube 1.
Sealed to 0. As a result, the surge absorber 20 in which the argon gas 14 is enclosed is produced. Due to the presence of the Cu 2 O film, the sealing electrodes 11 and 12 are sealed at a low temperature of about 700 ° C.
【００１１】ガラス管１０の両端に封着された封止電極
１１及び１２の各外面にリード１５及び１６がはんだ付
けされる。はんだ付け性を良くするために封止電極の外
面を塩酸で洗浄して、封着時に封止電極の外面に形成さ
れた銅薄膜上の酸化膜（Ｃｕ 2Ｏ膜）を除去する。この
酸化膜は容易に除去され、リード線１５及び１６を容易
にはんだ付けされる。Sealing electrodes sealed at both ends of the glass tube 10.
Leads 15 and 16 are soldered to the outer surfaces of 11 and 12, respectively.
Be injured. Outside the sealing electrode to improve solderability
Clean the surface with hydrochloric acid and form on the outer surface of the sealing electrode during sealing.
Oxide film (Cu 2O film) is removed. this
The oxide film is easily removed and the lead wires 15 and 16 are easily removed.
Be soldered to.
【００１２】銅薄膜１１ｂによる電極素体１１ａとガラ
ス管１０との熱膨張係数の調整度を調べるため、電極素
体１１ａ（鉄−ニッケル合金）の厚さ(Ａ)と銅薄膜１１
ｂの厚さ(Ｂ，Ｃ)を変えて封着後のガラス管１０のクラ
ックの発生の有無を目視により確認した。具体的には、
銅薄膜の厚さ(Ｂ＋Ｃ)に対する封止電極全体の厚さ（Ａ
＋Ｂ＋Ｃ）の比率(Ｐ)が２０％、３０％、４５％、５０
％及び６０％になるように、銅薄膜の厚さ(Ｂ，Ｃ)及び
鉄−ニッケル合金の厚さ(Ａ)を変えた。その結果を表１
及び図３に示す。図３において、たて軸は熱膨張係数、
よこ軸は比率(Ｐ)を示す。またたて軸の符号Ｅは鉄４２
％とニッケル５８％の合金の熱膨張係数、符号Ｆは銅の
熱膨張係数、符号Ｇは鉛ガラスの熱膨張係数をそれぞれ
表わす。これらの結果より、銅薄膜１１ｂの厚さは封止
電極全体の厚さの３０〜４５％が適していることが判明
した。In order to check the degree of adjustment of the coefficient of thermal expansion between the electrode body 11a and the glass tube 10 by the copper thin film 11b, the thickness (A) of the electrode body 11a (iron-nickel alloy) and the copper thin film 11 are examined.
The thickness (B, C) of b was changed and the presence or absence of cracks in the glass tube 10 after sealing was visually confirmed. In particular,
The total thickness of the sealing electrode (A + B + C)
+ B + C) ratio (P) is 20%, 30%, 45%, 50
% And 60%, the thickness of the copper thin film (B, C) and the thickness of the iron-nickel alloy (A) were changed. The results are shown in Table 1.
And shown in FIG. In FIG. 3, the vertical axis represents the coefficient of thermal expansion,
The horizontal axis shows the ratio (P). Also, the code E of the vertical shaft is iron 42
% And nickel 58% alloy thermal expansion coefficient, symbol F represents copper thermal expansion coefficient, and symbol G represents lead glass thermal expansion coefficient. From these results, it was found that the thickness of the copper thin film 11b is preferably 30 to 45% of the total thickness of the sealing electrode.
【００１３】[0013]
【表１】 [Table 1]
【００１４】＜比較例＞電極素体にニッケル４２％−ク
ロム６％−鉄５２％の合金を用い、電極素体にＣｒ2Ｏ3
を形成して封止電極とした。この封止電極と実施例と同
じガラス管及びサージ吸収素子を用いてアルゴンガス入
りサージアブソーバを作製した。このときの封着温度は
９００℃以上であった。この比較例のサージアブソーバ
と、上述した比率(Ｐ)が４５％の実施例のサージアブソ
ーバの各サージ耐量及び寿命を測定した。その結果を表
２に示す。サージ耐量はＪＥＣ−２１２（電気学会、電
気規格調査会標準規格）に規定される（８×２０）μ秒
のサージ電流を用いて測定した。また寿命はＩＥＣ−Ｐ
ｕｂ．６０−２に規定される（１．２×５０）μ秒の１
０ｋＶのサージ電圧を繰返し印加してサージ吸収性能の
劣化が始る回数を調べた。表２より比較例のサージアブ
ソーバより実施例のサージアブソーバは封着温度が２０
０℃以上低く、しかもサージ耐量が大きく、寿命が長い
ことが判明した。 （以下、本頁余白）Comparative Example A nickel 42% -chromium 6% -iron 52% alloy was used for the electrode body, and Cr 2 O 3 was used for the electrode body.
To form a sealing electrode. A surge absorber containing argon gas was produced using this sealing electrode, the same glass tube and surge absorbing element as in the example. The sealing temperature at this time was 900 ° C. or higher. The surge withstanding capacity and life of each of the surge absorber of this comparative example and the surge absorber of the example in which the ratio (P) was 45% were measured. The results are shown in Table 2. The surge withstand capability was measured using a surge current of (8 × 20) μsec defined in JEC-212 (standards of the Institute of Electrical Engineers of Japan, Electrical Standards Research Committee). The life is IEC-P
ub. 1 of (1.2 × 50) μsec specified in 60-2
A surge voltage of 0 kV was repeatedly applied to examine the number of times the deterioration of the surge absorption performance started. From Table 2, the sealing temperature of the surge absorber of the embodiment is 20 from that of the surge absorber of the comparative example.
It was found that the temperature was lower than 0 ° C, the surge resistance was large, and the life was long. (Hereafter, margins on this page)
【００１５】[0015]
【表２】 [Table 2]
【００１６】[0016]
【発明の効果】以上述べたように、本発明によれば、次
の効果を奏する。 銅薄膜による熱膨張係数の調整により、鉄及びニッ
ケルを含む合金の熱膨張係数がガラスの熱膨張係数に近
づくため、封着時のガラス管のクラック発生を防止する
ことができる。 従来、鉄−ニッケル合金では酸化膜が厚くなりす
ぎ、ガスバーナの炎を必要とし、不活性ガス雰囲気中で
は封着できなかったものが、本発明では鉄−ニッケル合
金であっても銅薄膜上のＣｕ2Ｏ膜の存在により不活性
ガス雰囲気中でカーボンヒータで封着することができ
る。 本発明の封止電極の素体が鉄−ニッケル合金の場
合、銅薄膜上のＣｕ2Ｏ膜の存在により、従来の鉄−ニ
ッケル−クロム合金の封止電極より約２００℃低い温度
で封着することができ、ガラス管内部のマイクロギャッ
プ式サージ吸収素子の導電性皮膜の熱ストレスが緩和さ
れる。 本発明の封止電極の内面のＣｕ2Ｏ膜は電子放射促
進作用があるため、サージ電圧の印加時にはマイクロギ
ャップ付近で開始されたアーク放電がマイクロギャップ
及び導電性皮膜から離れた封止電極間で容易に行われる
ようになる。 上記及びにより、導電性皮膜の熱損傷がなくなりサ
ージアブソーバのサージ耐量を大きくできるとともに、
寿命を長くすることができる。 封着後封止電極の外面にリード線を接続するため
に、封止電極外面を塩酸で洗浄すると、封着により形成
された銅薄膜上の酸化膜（Ｃｕ2Ｏ膜）は簡単に除去さ
れリード線を容易にはんだ付けできる。As described above, the present invention has the following effects. By adjusting the coefficient of thermal expansion by the copper thin film, the coefficient of thermal expansion of the alloy containing iron and nickel approaches the coefficient of thermal expansion of glass, so that cracking of the glass tube during sealing can be prevented. Conventionally, the iron-nickel alloy has a too thick oxide film, requires a gas burner flame, and could not be sealed in an inert gas atmosphere. Due to the presence of the Cu 2 O film, it is possible to seal with a carbon heater in an inert gas atmosphere. For nickel alloy, the presence of Cu 2 O film on a copper film, a conventional iron - - body of the sealing electrodes of the present invention is an iron-nickel - sealing at about 200 ° C. lower temperature than the sealing electrodes chrome Therefore, the thermal stress of the conductive film of the microgap type surge absorbing element inside the glass tube is relieved. Since the Cu 2 O film on the inner surface of the sealing electrode of the present invention has an electron emission promoting action, the arc discharge started in the vicinity of the microgap at the time of applying the surge voltage is generated between the sealing electrodes separated from the microgap and the conductive film. Will be done easily. By the above and, the thermal damage of the conductive film is eliminated and the surge withstand capability of the surge absorber can be increased,
The life can be extended. After sealing, when the outer surface of the sealing electrode is washed with hydrochloric acid to connect the lead wire to the outer surface of the sealing electrode, the oxide film (Cu 2 O film) on the copper thin film formed by the sealing is easily removed. Lead wires can be easily soldered.
【図１】本発明実施例のサージアブソーバの要部断面
図。FIG. 1 is a sectional view of a main part of a surge absorber according to an embodiment of the present invention.
【図２】その外観斜視図。FIG. 2 is an external perspective view thereof.
【図３】その封止電極の銅薄膜の厚さに対する封止電極
全体の厚さの比率を変えたときの熱膨張係数の変化を示
す図。FIG. 3 is a diagram showing changes in the coefficient of thermal expansion when the ratio of the thickness of the entire sealing electrode to the thickness of the copper thin film of the sealing electrode is changed.
１０ ガラス管 １１，１２ 封止電極 １１ａ 電極素体 １１ｂ 銅薄膜 １１ｃ Ｃｕ2Ｏ膜 １３ サージ吸収素子 １３ａ 導電性皮膜 １３ｂ セラミックス素体 １３ｃ マイクロギャップ １３ｄ キャップ電極 １４ アルゴンガス（不活性ガス） １５，１６ リード線 ２０ サージアブソーバ10 Glass Tube 11, 12 Sealing Electrode 11a Electrode Element 11b Copper Thin Film 11c Cu 2 O Film 13 Surge Absorbing Element 13a Conductive Film 13b Ceramics Element 13c Micro Gap 13d Cap Electrode 14 Argon Gas (Inert Gas) 15, 16 Lead wire 20 Surge absorber
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成４年８月１８日[Submission date] August 18, 1992
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１２[Correction target item name] 0012
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１２】銅薄膜１１ｂによる電極素体１１ａとガラ
ス管１０との熱膨張係数の調整度を調べるため、電極素
体１１ａ（鉄−ニッケル合金）の厚さ(Ａ)と銅薄膜１１
ｂの厚さ(Ｂ，Ｃ)を変えて封着後のガラス管１０のクラ
ックの発生の有無を目視により確認した。具体的には、
封止電極全体の厚さ（Ａ＋Ｂ＋Ｃ）に対する銅薄膜の厚
さ(Ｂ＋Ｃ)の比率(Ｐ)が２０％、３０％、４５％、５０
％及び６０％になるように、銅薄膜の厚さ(Ｂ，Ｃ)及び
鉄−ニッケル合金の厚さ(Ａ)を変えた。その結果を表１
及び図３に示す。図３において、たて軸は熱膨張係数、
よこ軸は比率(Ｐ)を示す。またたて軸の符号Ｅは鉄４２
％とニッケル５８％の合金の熱膨張係数、符号Ｆは銅の
熱膨張係数、符号Ｇは鉛ガラスの熱膨張係数をそれぞれ
表わす。これらの結果より、銅薄膜１１ｂの厚さは封止
電極全体の厚さの３０〜４５％が適していることが判明
した。 ─────────────────────────────────────────────────────
In order to check the degree of adjustment of the coefficient of thermal expansion between the electrode body 11a and the glass tube 10 by the copper thin film 11b, the thickness (A) of the electrode body 11a (iron-nickel alloy) and the copper thin film 11 are examined.
The thickness (B, C) of b was changed and the presence or absence of cracks in the glass tube 10 after sealing was visually confirmed. In particular,
The ratio (P) of the thickness (B + C) of the copper thin film to the total thickness (A + B + C) of the sealing electrode is 20%, 30%, 45%, 50.
% And 60%, the thickness of the copper thin film (B, C) and the thickness of the iron-nickel alloy (A) were changed. The results are shown in Table 1.
And shown in FIG. In FIG. 3, the vertical axis represents the coefficient of thermal expansion,
The horizontal axis shows the ratio (P). Also, the code E of the vertical shaft is iron 42
% And nickel 58% alloy thermal expansion coefficient, symbol F represents copper thermal expansion coefficient, and symbol G represents lead glass thermal expansion coefficient. From these results, it was found that the thickness of the copper thin film 11b is preferably 30 to 45% of the total thickness of the sealing electrode. ─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成４年１２月２８日[Submission date] December 28, 1992
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００９[Correction target item name] 0009
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００９】[0009]
【実施例】次に、本発明の実施例を図面に基づいて詳し
く説明する。 ＜実施例＞図１及び図２に示すように、円筒形のガラス
管１０の両端に封止電極１１，１２が封着される。図で
は上端の封止電極１１を詳細に示す。この例では、ガラ
ス管１０は軟質ガラスの一種の鉛ガラスである。また封
止電極１１は、鉄５８％とニッケル４２％の合金からな
る電極素体１１ａと、電極素体１１ａを被包するように
形成された所定の厚さの銅薄膜１１ｂと、銅薄膜１１ｂ
の表面に形成されたＣｕ2Ｏ膜１１ｃとにより構成され
る。電極素体１１ａをガラス管１０に挿入し得るように
ハット状に成形した後、電極素体１１ａ全体を銅めっき
して素体表面に銅薄膜１１ｂを所定の厚さに形成する。
次いで銅薄膜１１ｂの形成された電極素体１１ａを高温
の酸素雰囲気下に置き、その後急冷して銅薄膜１１ｂ表
面にＣｕ2Ｏ膜１１ｃを形成する。ガラス管１０内には
マイクロギャップ式のサージ吸収素子１３が収容され
る。このサージ吸収素子１３は導電性皮膜１３ａで被包
した円柱状のセラミックス素体１３ｂの周面に数１０μ
ｍのマイクロギャップ１３ｃをレーザにより形成させた
後、セラミックス素体の両端にキャップ電極１３ｄを圧
入して作られる。Embodiments of the present invention will now be described in detail with reference to the drawings. <Example> As shown in FIGS. 1 and 2, sealing electrodes 11 and 12 are sealed at both ends of a cylindrical glass tube 10. In the figure, the sealing electrode 11 at the upper end is shown in detail. In this example, the glass tube 10 is a kind of soft glass lead glass. The sealing electrode 11 includes an electrode body 11a made of an alloy of 58% iron and 42% nickel, a copper thin film 11b having a predetermined thickness formed so as to enclose the electrode body 11a, and a copper thin film 11b.
And a Cu 2 O film 11c formed on the surface of the. After the electrode element body 11a is formed into a hat shape so that it can be inserted into the glass tube 10, the entire electrode element body 11a is plated with copper to form a copper thin film 11b on the surface of the element body with a predetermined thickness.
Next, the electrode element body 11a on which the copper thin film 11b is formed is placed in a high temperature oxygen atmosphere and then rapidly cooled to form a Cu 2 O film 11c on the surface of the copper thin film 11b. A microgap type surge absorbing element 13 is housed in the glass tube 10. The surge absorbing element 13 has a cylindrical ceramic body 13b covered with a conductive film 13a and has a peripheral surface of several tens of μm.
After forming the micro gap 13c of m by laser, cap electrodes 13d are press-fitted to both ends of the ceramic body.
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１２[Correction target item name] 0012
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１２】銅薄膜１１ｂによる電極素体１１ａとガラ
ス管１０との熱膨張係数の調整度を調べるため、電極素
体１１ａ（鉄−ニッケル合金）の厚さ(Ａ)と銅薄膜１１
ｂの厚さ(Ｂ，Ｃ)を変えて封着後のガラス管１０のクラ
ックの発生の有無を目視により確認した。具体的には、
封止電極全体の厚さ（Ａ＋Ｂ＋Ｃ）に対する銅薄膜の厚
さ(Ｂ＋Ｃ)の比率(Ｐ)が２０％、３０％、４５％、５０
％及び６０％になるように、銅薄膜の厚さ(Ｂ，Ｃ)及び
鉄−ニッケル合金の厚さ(Ａ)を変えた。その結果を表１
及び図３に示す。図３において、たて軸は熱膨張係数、
よこ軸は比率(Ｐ)を示す。またたて軸の符号Ｅは鉄５８
％とニッケル４２％の合金の熱膨張係数、符号Ｆは銅の
熱膨張係数、符号Ｇは鉛ガラスの熱膨張係数をそれぞれ
表わす。これらの結果より、銅薄膜１１ｂの厚さは封止
電極全体の厚さの３０〜４５％が適していることが判明
した。In order to check the degree of adjustment of the coefficient of thermal expansion between the electrode body 11a and the glass tube 10 by the copper thin film 11b, the thickness (A) of the electrode body 11a (iron-nickel alloy) and the copper thin film 11 are examined.
The thickness (B, C) of b was changed and the presence or absence of cracks in the glass tube 10 after sealing was visually confirmed. In particular,
The ratio (P) of the thickness (B + C) of the copper thin film to the total thickness (A + B + C) of the sealing electrode is 20%, 30%, 45%, 50.
% And 60%, the thickness of the copper thin film (B, C) and the thickness of the iron-nickel alloy (A) were changed. The results are shown in Table 1.
And shown in FIG. In FIG. 3, the vertical axis represents the coefficient of thermal expansion,
The horizontal axis shows the ratio (P). Also, the code E of the vertical shaft is iron 58.
% And the coefficient of nickel 42% alloy, the symbol F represents the coefficient of thermal expansion of copper, and the symbol G represents the coefficient of thermal expansion of lead glass. From these results, it was found that the thickness of the copper thin film 11b is preferably 30 to 45% of the total thickness of the sealing electrode.
【手続補正３】[Procedure 3]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１５[Correction target item name] 0015
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【００１５】[0015]
【表２】 ─────────────────────────────────────────────────────
[Table 2] ─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成５年３月２３日[Submission date] March 23, 1993
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】請求項２[Name of item to be corrected] Claim 2
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
Claims (4)
12)において、 鉄及びニッケルを含む合金からなる電極素体(11a)と、 前記電極素体(11a)を被包するように形成された所定の
厚さの銅薄膜(11b)と、 前記ガラス管(10)の内部に面する前記銅薄膜(11b)の表
面に形成されたＣｕ2Ｏ膜(11c)とを備えたことを特徴と
する封止電極。1. A sealing electrode (11, 11) which is sealed to a glass tube (10).
In 12), an electrode element body (11a) made of an alloy containing iron and nickel, and a copper thin film (11b) having a predetermined thickness formed so as to cover the electrode element body (11a), and the glass. A sealed electrode comprising: a Cu 2 O film (11c) formed on the surface of the copper thin film (11b) facing the inside of the tube (10).
極素体(11a)が鉄４２％とニッケル５８％の合金からな
り、前記電極素体(11a)の厚さと銅薄膜(11b)の厚さの合
計値に対する銅薄膜の厚さの比率が３０〜４５％である
請求項１記載の封止電極。2. The glass tube (10) is made of soft glass, the electrode body (11a) is made of an alloy of 42% iron and 58% nickel, the thickness of the electrode body (11a) and the copper thin film (11b). The sealing electrode according to claim 1, wherein the ratio of the thickness of the copper thin film to the total value of the thicknesses of 30 to 45%.
せることにより形成された請求項１記載の封止電極。3. The sealed electrode according to claim 1, wherein the Cu 2 O film (11c) is formed by oxidizing the copper thin film (11b).
包した円柱状のセラミックス素体(13b)の周面にマイク
ロギャップ(13c)が形成され、前記セラミックス素体(13
b)の両端に一対のキャップ電極(13d)を有するサージ吸
収素子(13)と、 前記ガラス管(10)の両端に封着した状態で前記サージ吸
収素子(13)を固定し、かつ前記一対のキャップ電極(13
d)に電気的に接続された請求項１記載の封止電極(11,1
2)と、 前記封止電極(11,12)と前記ガラス管(10)とにより形成
される空間に封入された不活性ガス(14)とを備えたサー
ジアブソーバ。4. A microgap (13c) is provided on the peripheral surface of a glass tube (10) and a cylindrical ceramic body (13b) housed in the glass tube (10) and covered with a conductive film (13a). ) Is formed, and the ceramic body (13
b) a surge absorbing element (13) having a pair of cap electrodes (13d) at both ends, and the surge absorbing element (13) is fixed in a sealed state at both ends of the glass tube (10), and Cap electrode (13
The sealed electrode (11, 1) according to claim 1, which is electrically connected to (d).
A surge absorber comprising 2) and an inert gas (14) enclosed in a space formed by the sealing electrodes (11, 12) and the glass tube (10).
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4076356A JP2541068B2 (en) | 1992-02-27 | 1992-02-27 | Sealing electrode and surge absorber using the same |
| DE4390682T DE4390682T1 (en) | 1992-02-27 | 1993-02-25 | Locking electrode and its use in surge protection |
| KR1019930703228A KR0139509B1 (en) | 1992-02-27 | 1993-02-25 | Sealing electrode and surge absorber using the same |
| GB9321710A GB2272329B (en) | 1992-02-27 | 1993-02-25 | Sealing electrode and surge absorber using the same |
| CA002107679A CA2107679A1 (en) | 1992-02-27 | 1993-02-25 | Sealing electrode and surge absorber using such electrodes |
| US08/140,028 US5506071A (en) | 1992-02-27 | 1993-02-25 | Sealing electrode and surge absorber using the same |
| DE4390682A DE4390682C2 (en) | 1992-02-27 | 1993-02-25 | Overvoltage protection |
| PCT/JP1993/000234 WO1993017475A1 (en) | 1992-02-27 | 1993-02-25 | Sealing electrode and surge absorber using such electrodes |
| TW082101956A TW219403B (en) | 1992-02-27 | 1993-03-17 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4076356A JP2541068B2 (en) | 1992-02-27 | 1992-02-27 | Sealing electrode and surge absorber using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05242950A true JPH05242950A (en) | 1993-09-21 |
| JP2541068B2 JP2541068B2 (en) | 1996-10-09 |
Family
ID=13603086
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4076356A Expired - Lifetime JP2541068B2 (en) | 1992-02-27 | 1992-02-27 | Sealing electrode and surge absorber using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2541068B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01124983A (en) * | 1987-11-09 | 1989-05-17 | Okaya Electric Ind Co Ltd | Surge absorbing element |
| JPH01186579A (en) * | 1988-01-14 | 1989-07-26 | Mitsubishi Mining & Cement Co Ltd | Microgap type surge absorption element |
| JPH0377292A (en) * | 1989-08-18 | 1991-04-02 | Hitachi Cable Ltd | Electrode material for shock absorber and surge absorber using the same material |
| JPH0377293A (en) * | 1989-08-18 | 1991-04-02 | Hitachi Cable Ltd | Electrode material for shock absorber and surge absorber using the same material |
| JPH03214580A (en) * | 1990-01-16 | 1991-09-19 | Mitsubishi Materials Corp | Micro-gap type surge absorbing element |
-
1992
- 1992-02-27 JP JP4076356A patent/JP2541068B2/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01124983A (en) * | 1987-11-09 | 1989-05-17 | Okaya Electric Ind Co Ltd | Surge absorbing element |
| JPH01186579A (en) * | 1988-01-14 | 1989-07-26 | Mitsubishi Mining & Cement Co Ltd | Microgap type surge absorption element |
| JPH0377292A (en) * | 1989-08-18 | 1991-04-02 | Hitachi Cable Ltd | Electrode material for shock absorber and surge absorber using the same material |
| JPH0377293A (en) * | 1989-08-18 | 1991-04-02 | Hitachi Cable Ltd | Electrode material for shock absorber and surge absorber using the same material |
| JPH03214580A (en) * | 1990-01-16 | 1991-09-19 | Mitsubishi Materials Corp | Micro-gap type surge absorbing element |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2541068B2 (en) | 1996-10-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7570473B2 (en) | Surge absorber | |
| US5506071A (en) | Sealing electrode and surge absorber using the same | |
| JP2541069B2 (en) | Sealing electrode and surge absorber using the same | |
| JP2541068B2 (en) | Sealing electrode and surge absorber using the same | |
| JP2910007B2 (en) | surge absorber | |
| JP2910006B2 (en) | surge absorber | |
| JP4544255B2 (en) | Electronic component enclosure | |
| JP3134905B2 (en) | surge absorber | |
| JP4265321B2 (en) | surge absorber | |
| JPH0443584A (en) | Gas-tight structure of surge absorbing element | |
| JP3134912B2 (en) | surge absorber | |
| JPH11224761A (en) | High voltage surge absorber | |
| JPS58198884A (en) | Surge absorbing element | |
| JP2853010B2 (en) | Surge absorbing element and method of manufacturing the same | |
| GB2040912A (en) | Electric lamp with metallic sealing plugs | |
| JPH1022042A (en) | Electronic part sealing body | |
| JP2000077163A (en) | Surface mounted surge absorbing element | |
| JP4239422B2 (en) | surge absorber | |
| JP2021120943A (en) | Surge protective element and manufacturing method of the same | |
| JPH0878133A (en) | Serge absorber | |
| JP2022138781A (en) | Surge protection element and manufacturing method thereof | |
| JPH0722152A (en) | Surge absorber and its manufacture | |
| JPH10247578A (en) | Manufacture of discharging serge absorption element | |
| KR100199694B1 (en) | Surge absorber | |
| JP4682918B2 (en) | Nonlinear capacitor, manufacturing method thereof, and high-pressure metal vapor discharge lamp using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 19960528 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080725 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080725 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090725 Year of fee payment: 13 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090725 Year of fee payment: 13 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100725 Year of fee payment: 14 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100725 Year of fee payment: 14 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100725 Year of fee payment: 14 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110725 Year of fee payment: 15 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110725 Year of fee payment: 15 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120725 Year of fee payment: 16 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120725 Year of fee payment: 16 |