JPH11203997A - Manufacturing method of vacuum valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a vacuum valve capable of obtaining a vacuum valve with its superior air tightness and junction strength by using an active metal brazing material. SOLUTION: A layer including an active metal such as Ti is formed on one side of a metal plate consisting essentially of Ag or Cu, and heat-treated in vacuum or inert gas, after which this is punched in a hollow disk, this hollow disk is used as an active metal brazing material, and a cylindrical insulation container and a cover body are bonded with each other, thereby a vacuum valve is manufactured. By performing heat treatment, the active metal layer is never peeled off during punching, a superior active metal brazing metal can be obtained, and this brazing material is used, thereby a vacuum valve with its superior air tightness and junction strength can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vacuum valve, and more particularly to a brazing material for hermetically sealing an insulating container and a lid.

[0002]

2. Description of the Related Art Conventionally, for airtight sealing between a cylindrical insulating container and a metal lid, Mo-Mn or the like is baked on both bottom surfaces of the insulating container at a high temperature to form a metallizing layer, and then silver is formed. The Mo-Mn method (high melting point method) for joining with a braze or the like is known. However, such a method has a problem in complicated steps, such as requiring a heat treatment at a high temperature (1700 K or more) at the time of metallizing.

[0003] Therefore, an attempt has been made to join by an active metal method using an active metal such as Ti. Metals such as Ti and the like contribute to bonding by reacting (reducing reaction) with ceramic, and thus are often used in direct contact with the bonding surface with ceramic. For example, a method of dissolving Ti powder in an organic solvent and forming it in a cast form is applied to one surface of a brazing material (silver brazing or the like) of a hollow disk (ぺ 1st method), or a method in which Ti is formed on one surface of the brazing material by evaporation or the like. Is attached (evaporation method).

However, in the first method, when a large number of vacuum valves are produced, there is a problem that the evaporated organic solvent has a bad influence on a human body and a vacuum furnace. Further, in the vapor deposition method, Ti atoms are deposited not only on one side of the target brazing material but also on a side surface and a surface on the opposite side from a small gap. In this case, Ti adhering to the surface opposite to the bonding surface with the insulating container is deposited inside the metal lid used for hermetic bonding (a metal lid having a small thermal expansion coefficient such as Kovar is often used). Forming intermetallic compounds with existing Ni,
There arises a problem that airtightness and bonding strength are reduced.

[0005] As a solution in this case, there is a method of masking the opposite surface of the hollow disk, or punching the hollow disk after depositing Ti. However, masking the brazing material one by one complicates the process, and if an organic substance such as an adhesive adheres to the brazing material, it causes a reduction in bonding property. In a method in which Ti is vapor-deposited on a brazing material mainly composed of Ag and Cu and then punched into a hollow disk, the deposited Ti may be partially peeled off due to the impact of the punching. Only the part where the flakes are peeled off is not joined, and the joinability is reduced. A method of intentionally increasing the thickness of the Ti layer so that the base does not appear when punching is considered, but in this case, Ti that does not contribute to the reaction with the insulating container is composed of Ni and the intermetallic compound in the metal lid. Is formed, and the problem that the joinability is reduced occurs.

[0006]

SUMMARY OF THE INVENTION As described above, Ti
When using an active metal such as an active metal, airtight sealing is performed, and when an active metal layer such as Ti is formed on one surface of the brazing material of the hollow disk by vapor deposition, the surface and the side opposite to the target surface are formed. Also Ti
In some cases, atoms of an active metal such as a metal may be attached, and the hermeticity and bonding strength may be reduced, which is problematic in terms of reliability.

The present invention has been made in view of such problems, and provides a method of manufacturing a vacuum valve capable of obtaining a vacuum valve having excellent airtightness and bonding strength by using an active metal brazing material. The purpose is to do.

[0008]

SUMMARY OF THE INVENTION According to the present invention, an active metal brazing material is melted in a vacuum atmosphere, and hermetically bonded to a cylindrical insulating container and a lid provided with electrodes, a current-carrying shaft, and the like to form a vacuum valve. In the method of manufacturing a vacuum valve to be manufactured, a film forming step of forming a layer containing an active metal on one surface of a metal plate containing Ag or Cu as a main component, and improving the adhesion strength between the layer containing the active metal and the metal plate Therefore, a heat treatment step of heat treatment, a punching step of punching a metal plate on which a layer containing an active metal is formed into a hollow disk, and using the hollow disk as an active metal brazing material, forming a cylindrical insulating container and a lid. And a joining step of joining the two.

According to such a manufacturing method, a vacuum valve having excellent airtightness and bonding strength can be obtained using an active metal brazing material. Here, the heat treatment step can be performed at a temperature of 500 ° C. or lower after the completion of the film formation step or simultaneously with the film formation step.

The heat treatment step can be performed in a vacuum atmosphere having a pressure of 1 Pa or less, or in an Ar, He, or nitrogen atmosphere. The thickness of the layer containing the active metal can be 0.01 to 10 μm.

Further, the active metals are Ti, Zr, Hf, N
It can be at least one of b, Ta, and Cr. Further, a metal plate containing Ag or Cu as a main component
It can be a clad material composed of at least two or more layers of g-Cu or Ag or Cu.

Further, the metal plate containing Ag or Cu as a main component is made of at least one of In, Sn, Mn, Zn and Cd.
One. The lid is made of any one of stainless steel, Fe-Ni alloy, Fe-Ni-Co alloy, and Ni-Cu alloy, or this material is coated with one of Ni and Cu. Can be.

The cylindrical insulating container can contain Al ₂ O ₃ or SiO ₂ as a main component. Further, the cylindrical insulating container may contain 85 wt% or more of Al ₂ O ₃ , and the remainder may be substantially composed of SiO ₂ .

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a vacuum valve manufactured according to the present invention will be described with reference to FIGS.

FIG. 1 shows an example of the configuration of a vacuum valve to which a contact material manufactured according to the present invention is applied. In FIG. 1, reference numeral 1 denotes a shut-off chamber, and the shut-off chamber 1 is made of an insulating material. An insulating container 2 formed in a substantially cylindrical shape, and metallic lids 4a, 4a provided at both ends thereof via sealing fittings 3a, 3b.
and b. (Note that the sealing fitting 3
a may be formed integrally with the lid 4a, and the sealing fitting 3b may be formed integrally with the lid 4b. A pair of electrodes 7 and 8 attached to opposing ends of the conductive rods 5 and 6 are provided in the shut-off chamber 1. The upper electrode 7 is a fixed electrode, and the lower electrode 8 is movable. Electrodes.

A bellows 9 is attached to the conductive rod 6 of the movable electrode 8 to enable the electrode 8 to move in the axial direction while keeping the inside of the cut-off chamber 1 airtight. An arc shield 10 is provided to prevent the bellows 9 from being covered with arc vapor.
Reference numeral 11 denotes a metallic arc shield provided in the shut-off chamber 1 so as to cover the electrodes 7 and 8, and prevents the insulating container 2 from being covered with the arc vapor.

Further, as shown in an enlarged manner in FIG. 2, the electrode 8 is fixed to the conductive rod 6 by a brazing portion 12, or is connected by crimping by crimping. Contact 1
3a is fixed to the electrode 8 by a brazing portion 14. In addition, 13b in FIG. 1 is a fixed side contact.

In particular, this embodiment relates to a method for hermetically joining the insulating container 2 and the lids 4a and 4b by using an active metal brazing material via the sealing fittings 3a and 3b. As described above, using an active metal such as Ti, in order to hermetically join a vacuum valve between a ceramic insulating container and a metal or ceramic lid, without using an organic solvent, silver or silver. It is desirable to use an active metal brazing material having a layer containing an active metal such as Ti on only one side of a brazing material containing copper as a main component. Masking is a method for preventing the active metal from adhering to the side surface of the hollow disk, or from escaping to the opposite surface of the target surface from a slight gap,
The process becomes complicated, and if an organic substance such as an adhesive adheres to the brazing material, it causes a reduction in bonding property.

Therefore, for example, if an active metal such as Ti is punched after forming a film on a brazing material plate larger than the target shape, the active metal such as Ti does not exist in a portion other than the target. In the embodiment of the present invention, first, an active metal brazing material is manufactured by the following method. (1) Film forming step: a step of forming a layer containing an active metal on one side of a metal plate containing Ag or Cu as a main component. (2) Heat treatment step: a layer containing an active metal and Ag or Cu
(3) Punching step: It consists of three steps of punching out a hollow disk.

That is, during the process of forming an active metal such as Ti on a brazing material and punching it into a hollow disk, in order to improve the adhesion strength between the underlying brazing material and the layer containing the active metal, a vacuum or Heat treatment in an inert gas. This prevents the active metal layer from peeling off at the time of punching, so that an excellent active metal brazing material can be obtained.

Next, a method of manufacturing a vacuum valve using the active metal brazing material thus obtained will be described.
Basically, (1) Both sides of a ceramic insulating container, for example, an Al ₂ O ₃ cylindrical container having an outer diameter of 50 mm, an inner diameter of 40 mm, and a height of 50 mm are activated on one side of a brazing material mainly composed of Ag or Cu. An assembling step in which a hollow circular active metal brazing material having a metal-containing layer is disposed, and a lid body having electrodes, a current-carrying shaft, and the like is further disposed thereon. It consists of two steps of an air-tight joining step of holding at a temperature higher than the temperature at which the brazing material starts to melt, for example, 900 ° C. for a predetermined time, for example, 10 minutes, and then cooling.

According to this method, a vacuum valve can be manufactured more easily and inexpensively by using an active metal brazing material using a film forming method such as a vapor deposition method, sputtering, ion plating, CVD (chemical vapor deposition), and electroplating. Made it possible.

Hereinafter, specific examples of the method of manufacturing the vacuum valve according to this embodiment, comparative examples, and test results thereof will be described with reference to FIGS. In the test results, the airtightness was expressed in three stages according to the leak amount. In other words, ○ the following ^{10 -10 Pa · m 3 / s} , 10 -10
〜１０10 ⁻⁵ Pa · m ³ / s and × when 10 ^-5 Pa · m ³ / s or more (see margins in FIGS. 3 to 5). The tensile strength is shown as a relative value with the target value as 1.

The number of samples was 10 for each manufacturing condition. (Comparative Example 1, Examples 1 to 3) The lid and the sealing metal were SUS304L (stainless steel) with Ni plating on the surface, the ceramic container was Al ₂ O ₃ —SiO ₂ , and the brazing material was 300 μm thick. Ag-28Cu (the number before the element symbol indicates the weight ratio of each element), the layer containing the active metal is 0.1 μm thick Ti, and the vacuum valve is formed by the conventional method and the method according to this embodiment. Was manufactured, and the airtightness and the bonding strength were evaluated (Comparative Example 1, Example 1).

In the conventional method of Comparative Example 1, after a Ti film was formed and punched into a hollow disk having a predetermined shape without heat treatment, Ti was peeled off in some places, and the underlying Ag—Cu was visible.
When a vacuum valve was manufactured using this active metal brazing material, the result of the leak test was 10 ⁻⁴ Pa · m ³ / s, the bonding strength was 0.8 times the target value, and both values were insufficient. Was.

In Example 1, a film was formed on a brazing material Ag-28Cu by ion plating, heat-treated at 300 ° C. in a vacuum atmosphere of 0.1 Pa, and punched into a hollow disk. However, as a result of using this active metal brazing material, it was possible to obtain a vacuum valve having excellent airtightness and bonding strength.

In Examples 2 and 3, Ag-10Cu and Ag-50Cu were used as brazing materials, respectively.
After heat-treated while forming a film of Ti at 300 ° C. in a vacuum, it was punched into a hollow disk, and the Ti layer did not peel off. As a result of using this active metal brazing material, excellent airtightness and bonding were obtained. A vacuum valve having strength was obtained.

(Examples 4 and 5, Comparative Example 2) In Comparative Example 1 and Examples 1 to 3, the case of heat treatment at 300 ° C. has been described, but the heat treatment temperature is not limited to this.

In Examples 4 and 5, 100, 50
As a result of heat treatment at 0 ° C., a vacuum valve having excellent airtightness and bonding strength was obtained. However, in Comparative Example 2, when heat-treated at 600 ° C., the brazing material of Ag-28Cu softened and could not be punched into a target shape.

(Comparative Example 3, Examples 6 to 10) In Comparative Examples 1 to 2 and Examples 1 to 5, the case where heat treatment was performed in a vacuum atmosphere of 0.1 Pa was described, but the heat treatment atmosphere is not limited to this. No need.

In Comparative Example 3, when heat treatment was performed in a vacuum atmosphere of 10 Pa, Ti on the surface was oxidized, and the active metal brazing material and the insulating container did not react and were not joined.

In Examples 6 and 7, 1 Pa, 0.
When heat treatment was performed in a vacuum atmosphere of 01 Pa, a vacuum valve having excellent airtightness and bonding strength could be obtained. In Examples 8 to 10, the heat treatment atmosphere was changed to A
When r, He, and N ₂ were used, a vacuum valve having excellent airtightness and bonding strength could be obtained.

(Comparative Examples 4 to 5, Examples 11 to 13) In Comparative Examples 1 to 3 and Examples 1 to 10, the case where the thickness of the active metal Ti is 0.1 μm has been described.
Is not limited to this.

In Comparative Example 4, the thickness of Ti was set to 0.005 μm.
At m, Ti and ceramic did not react and were not joined. In Examples 11 to 13, when the thickness of Ti was 0.01 μm, 1 μm, and 10 μm, respectively, a vacuum valve having excellent airtightness and bonding strength could be obtained.

In Comparative Example 5, when the thickness of Ti was set to 20 μm, a large amount of an intermetallic compound mainly composed of Ni and Ti was formed at the joint, and the airtightness and the joint strength were insufficient. Was.

(Examples 14 to 19) Comparative Examples 1 to 5,
In the first to thirteenth embodiments, the case where Ti is formed by ion plating is described as a layer containing an active metal, but the layer containing an active metal is not limited to this.

In Examples 14 to 18, Zr and H were formed by high frequency sputtering as layers containing an active metal.
When f, Nb, Ta, and Cr were used, a vacuum valve having excellent airtightness and bonding strength could be obtained.

In Example 19, a 10 μm thick Ag-1 film formed by composite electroplating was used as a layer containing an active metal.
When Ti was used, a vacuum valve having excellent airtightness and bonding strength could be obtained.

Examples 20 to 22 Comparative Examples 1 to 5,
In Examples 1 to 19, the case where a single layer of Ag-Cu was used as the brazing material mainly composed of Ag or Cu was described, but the brazing material mainly composed of Ag or Cu is not limited to this. .

In Examples 20 to 22, Ag / Cu (150 μm each), Ag-72Cu / Ag / Ag-72Cu were used as the brazing material mainly composed of Ag or Cu.
(Each 100 μm), Ag / Cu / Ag (each 100 μm)
As a result, a vacuum valve having excellent airtightness and bonding strength was obtained.

Examples 23 to 27 Comparative Examples 1 to 5,
In Examples 1 to 22, the case where the brazing material containing Ag or Cu as a main component was composed of Ag and Cu was described, but the brazing material containing Ag or Cu as a main component is not limited to this.

In Examples 23 to 27, as a brazing material containing Ag or Cu as a main component, a brazing material obtained by adding 4 wt% of In, Sn, Mn, Zn, and Cd to Ag-27Cu was used. The heat treatment temperature in the joining step can be reduced by 50 ° C.,
A vacuum valve having bonding strength was obtained.

When In, Sn, Mn, Zn, and Cd are less than 0.1% by weight, there is no difference in the heat treatment temperature.
At t% or more, the material was significantly embrittled, resulting in a decrease in strength.

Examples 28 to 30 Comparative Examples 1 to 5
In Examples 1 to 27, the surface of the cover and the sealing metal were N
Although the case of using SUS304L subjected to i-plating has been described, the lid and the sealing metal are not limited to this.

In Examples 28 to 30, Fe-42Ni (Cu plating on the surface), Fe-29Ni-17Co, and Ni-45Cu were used as the lid and the sealing metal, respectively. Was obtained.

(Comparative Example 6, Examples 31 to 33) In Comparative Examples 1 to 5 and Examples 1 to 30, the case where Al ₂ O ₃ -5 wt% SiO ₂ was used as a ceramic insulating container was described. However, the ceramic insulating container is not limited to this.

In Comparative Example 6, when the ceramic insulating container was made of Al ₂ O ₃ -20 wt% SiO ₂ , the airtightness was satisfactory, but the bonding strength was low. In Examples 31 to 33, the insulating containers made of ceramic were Al ₂ O ₃ -9 wt% SiO ₂ and Al ₂ O ₃ -1w, respectively.
When using _{t% SiO 2 99.9wt% Al 2} O 3, it was possible to obtain a vacuum valve having excellent airtightness, the bonding strength. From these data, it can be seen that the bonding strength is 1.0
This is considered to be the case when Al ₂ O ₃ is 85 wt% or more.

As described above, the ceramic insulating container and the lid are sealed to each other through the brazing material having a layer containing an active metal such as Ti on only one side of the brazing material mainly composed of Ag or Cu. And airtight joining in a vacuum through the, both airtightness and joining strength could be satisfied.

Even if a ceramic insulating container, a lid, a sealing metal, a brazing material, and an active metal, which are not described in this embodiment, are used, they can be hermetically joined under appropriate conditions. A good vacuum valve can be manufactured in the same manner as the embodiment.

[0050]

According to the present invention described above, the active metal is contained on only one side of the brazing material containing Ag or Cu as a main component by having three steps of a film forming step, a heat treatment step, and a punching step. A hollow disk active metal brazing material having a layer can be manufactured, and by using the active metal brazing material, a vacuum valve having excellent airtightness and bonding strength can be manufactured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a vacuum valve manufactured by the present invention according to the present invention.

FIG. 2 is an enlarged sectional view of a contact portion of the vacuum valve shown in FIG.

FIG. 3 is a table showing test results of Examples 1 to 10 and Comparative Examples 1 to 3 of the present invention.

FIG. 4 shows Examples 11 to 19 of the present invention and Comparative Examples 4 and 5.
FIG. 4 is a table showing test results of the test.

FIG. 5 is a table showing test results of Examples 20 to 33 of the present invention and Comparative Example 6.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Interruption chamber 2 ... Insulating container 3a, 3b ... Sealing metal 4a, 4b ... Lid 5, 6 ... Conductive rod 7 ... Fixed electrode 8 ... Movable electrode 9 ... Bellows 10, 11 ... Arc shield 12, 14 ... Brazing Part 13a: movable contact 13b: fixed contact

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiyo Seki 1 Toshiba-cho, Fuchu-shi, Tokyo, Japan Inside the Toshiba Fuchu Plant, Inc. 72) Inventor Osamu Kiyoshi 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu plant of Toshiba Corporation

Claims (10)

[Claims] 1. A method of manufacturing a vacuum valve, comprising: melting an active metal brazing material in a vacuum atmosphere; and hermetically joining the cylindrical insulating container and a lid provided with electrodes and a current-carrying shaft to manufacture a vacuum valve. A film forming step of forming a layer containing an active metal on one side of a metal plate containing Ag or Cu as a main component; and a heat treatment of performing a heat treatment to improve the adhesion strength between the layer containing the active metal and the metal plate. And a punching step of punching the metal plate on which a layer containing an active metal is formed into a hollow disk, using the hollow disk as an active metal brazing material, and joining the cylindrical insulating container and the lid. A method of manufacturing a vacuum valve, comprising: 2. The method according to claim 1, wherein the heat treatment step is performed at a temperature of 500 ° C. or less after completion of the film formation step or simultaneously with the film formation step. 3. The vacuum valve according to claim 1, wherein the heat treatment step is performed in a vacuum atmosphere having a pressure of 1 Pa or less or in an Ar, He, or nitrogen atmosphere. Production method. 4. The thickness of the layer containing the active metal is 0.01
The method for manufacturing a vacuum valve according to claim 1, wherein the thickness is set to 10 μm to 10 μm. 5. The active metal is Ti, Zr, Hf, N
5. The method according to claim 1, wherein at least one of b, Ta, and Cr is used. 6. The metal plate containing Ag or Cu as a main component is a clad material composed of at least two layers of Ag—Cu or Ag or Cu. The method for producing a vacuum valve according to any one of the above. 7. The metal plate containing Ag or Cu as a main component contains at least one of In, Sn, Mn, Zn, and Cd. 7. The method for manufacturing a vacuum valve according to any one of 6. 8. The lid body is made of any one of stainless steel, Fe-Ni alloy, Fe-Ni-Co alloy and Ni-Cu alloy, or this material is coated with Ni or Cu. 2. The method according to claim 1, wherein
A method for manufacturing a vacuum valve according to claim 7. 9. The method according to claim 1, wherein the cylindrical insulating container contains Al ₂ O ₃ or SiO ₂ as a main component. 10. The cylindrical insulating container according to claim 1, wherein the cylindrical insulating container contains at least 85 wt% of Al ₂ O ₃ , and the remainder is substantially composed of SiO ₂ . 3. The method for manufacturing a vacuum valve according to claim 1.