JPS5813513B2 - Sealing method between metal parts and insulating members - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for sealing metal parts and insulating members, particularly in electron tubes such as magnetrons. The present invention relates to a sealing method for bonding metal parts to ceramic materials.

FIGS. 1a to 1c are sectional views of essential parts of an example of a conventional magnetron.

In the figure, 1 is a cylindrical anode having a cathode 2 in the center and a vane 3 on the inner wall.

End shields 4a and 4b are provided at both ends of the cathode 2 to restrict the radiation range of thermionic electrons and to hold the cathode 2.
are arranged respectively, and these end shields 4a,
4b has a center support 5a and a side support 5.
b are disposed to support the end shields 4a, 4b, and also serve as electrical leads for supplying input to the cathode 2 from the outside and extend outward.

In addition, magnetic poles 6 and 7 formed in a mortar shape and protruding inward are fixed to both ends of the cylindrical anode 1, and a working space 8 is formed by the cathode 2 and the tips of the vanes 3.
It has the function of effectively guiding the magnetic field inside the magnet.

Seal plates 9 and 10 made of iron plates and shaped like flowerpots are attached to the outer surfaces of both magnetic poles 6 and 7, and their flanges 9a and 10a are attached to both end surfaces of the anode 1. It is fixed by arcing etc.

Further, an insulator 12 made of a ceramic material is fixed to the outer surface of the lower seal plate 10 by brazing or the like via a washer-shaped sealing material 11 made of Kovar, Fe-Ni, or the like.

The center support 5a is located approximately at the center of the magnetic pole 7, the seal plate 10, the sealing material 11, and the insulator 12.
The other end side of the side support 5b is penetrated, and the insulator 1
The protrusion side of the outer surface of 2 is made of small diameter Kovar or Fe-
It is firmly fixed by brazing or the like via a sealing material 13 such as Ni.

In this case, when bonding the insulating material 12 to the sealing plate 10 formed of an iron plate or the like, the sealing material 11 formed of Kovar or Fe-Ni is used instead of the insulating material 12 formed of a ceramic material or the like. This is because the coefficients of thermal expansion are almost the same.

On the other hand, on the upper surface of the upper sealing material 9, an insulating pipe 15 made of a cylindrical ceramic material is fixed by brazing through a washer-like sealing material 14 made of Kovar or Fe-Ni. There is.

Further, a sealing cup 16 made of copper or the like is fixed to the tip of the insulating pipe 15 by brazing, and an exhaust pipe 17 is provided at the tip of the sealing cup 16. Antenna 1 with one end connected
The other end of 8 is hermetically pressure welded.

The outer peripheral surface of the sealing cup 16 is covered with a cap-shaped exhaust pipe cover 19, which has the functions of protecting the press-contact portion of the exhaust pipe 17, preventing sparks due to electric field concentration, and functioning as a high-frequency antenna. The output section 20 is configured by the members.

The method for sealing metal parts and insulators such as ceramics in the input/output section of the magnetron configured as described above is as shown in Fig. 1b and c after metallizing the surface of the insulator.
As shown in detail in the cross-sectional view of the main part, on the output side, a brazing material 21 made of copper-silver alloy or the like is formed into a washer shape on the upper surface of the sealing material 9, which is made of an iron plate or the like in the shape of a flower pot. A sealing material 14 having approximately the same coefficient of thermal expansion as the insulating pipe 15 is disposed on the upper surface of the sealing material 1.
The same brazing material 21 as above is disposed on the upper surface of the insulating pipes 15, and the insulating pipes 15 are stacked.

A similar brazing material 21 is placed on the upper end surface of this insulating pipe 15, and a sealing cup 16 is also provided on the upper surface of this brazing material 21.

Further, an exhaust pipe 1 disposed on the upper surface of this sealing cup 16
A brazing material 22 made of copper-silver alloy or the like is provided around the joint portion 7 and assembled.

On the other hand, on the input section side, as shown in FIG. 1c, a brazing material 23 made of copper-silver alloy or the like is arranged in the shape of a washer on the lower surface of the sealing material 10, which is made of an iron plate or the like and made into a flowerpot shape. ,
A sealing material 11 having almost the same coefficient of thermal expansion as the ceramic insulator 12 is disposed on the lower surface of the brazing material 23, and furthermore, a brazing material 23 having the same shape as above is disposed on the lower surface of the sealing material 11. are arranged and the insulators 12 are stacked.

The center support 5a1 and the side supports 5b are penetrated through this insulator 12, and the outer surface side of the joint is sealed with a brazing material 24 made of the copper-silver alloy or the like formed in the shape of a small diameter washer. The material 13 is arranged and assembled.

In this way, the input and output side assemblies, which are assembled by laminating metal parts, insulating members, etc. alternately with brazing materials 21 to 24 on the outer surfaces of the sealing materials 9 and 10, are gently inserted into the heating furnace. By raising the temperature above the melting point of the soldering materials 21 to 24, the soldering materials 21 to 24 melt and metal parts such as the sealing materials 11 and 14 and the sealing cup 16 are formed on the upper surfaces of the sealing materials 9 and 10. A magnetron is constructed by bonding ceramic materials such as the insulating pipe 15 and the insulating body 12 to seal the respective parts.

In the magnetron configured as described above, when input is supplied from the outside to the center support 5a and side support 5b, the cathode 2 is heated, and when a predetermined voltage is supplied to the anode 1, thermionic electrons are generated from the cathode 2. is emitted.

These thermoelectrons act on the magnetic field in the working space 8 to generate high-frequency oscillation, and the oscillation output is conducted to the exhaust pipe 17 through the antenna 18 and radiated into the oven of a microwave oven, for example, through the exhaust pipe cover 19. That will happen.

However, in the magnetron with the above configuration,
When laminating, assembling, and sealing metal parts such as the sealing materials 9, 10 and sealing materials 11, 14 constituting the input section and the output section and ceramic materials such as the insulating pipe 15 and the insulator 12, The soldering materials 21 to 24 used for this purpose have various shapes, and are in the shape of large and small washers and rings, so a large amount of material is wasted in the process of forming the soldering materials 21 to 24. This results in a significant increase in production costs.

In addition, since there are an extremely large number of parts such as brazing materials 21 to 24 that are laminated and assembled on the outer surfaces of the sealing materials 9 and 10, positioning during lamination assembly is extremely difficult, and production thereof requires an extremely large number of man-hours. However, it has disadvantages such as extremely high production costs.

Therefore, an object of the present invention was to improve the above points, and to provide metal parts and insulating members that significantly reduce the number of parts, greatly increase the yield rate of brazing material, and that are easier to produce. The purpose is to provide a sealing method for

In order to achieve such an object, the method of sealing a metal component and an insulating member according to the present invention involves interposing a sealing material whose entire surface is coated with brazing material between the metal component and the ceramic insulating member. The two are bonded together by heating.

Hereinafter, a method for sealing a metal component and an insulating member according to the present invention will be described in detail with reference to the drawings.

FIGS. 2a to 2f are sectional views showing an embodiment applied to the input/output section of a magnetron in order to explain the method of sealing a metal part and an insulating member according to the present invention.

In the figure, the sealing material 25 disposed on the upper surface of the seal plate 9 on the output side is made by applying nickel plating of about 5 μm to the entire surface of a metal layer 25a made of metal such as Kovar in a washer shape. It is constructed by applying copper plating to a thickness of about 10 .mu.m, and further plating its surface to a thickness of about 20 .mu.m to form a nickel-copper-silver adhesion layer 25b which becomes a brazing material.

Further, the sealing cup 26 disposed on the upper end side of the insulating pipe 15 is coated with a 5μ film similar to the sealing material 25 on the entire surface of the metal layer 26a formed of Kovar or Fe-Ni.
A nickel-copper-silver adhesion layer 26b, which will become a brazing material, is formed by applying nickel plating to a thickness of about m, then copper plating to a thickness of about 10 μm, and then silver plating to a thickness of about 20 μm to the surface. It is configured.

Sealing material 25 and sealing cup 26 configured in this way
The sealing material 2 is attached to the upper surface of the sealing plate 9 as shown in FIG.
5. The metallized insulating pipe 15, the sealing cup 26, and the exhaust pipe 17 are stacked in this order and gently inserted into the heating furnace.

Then, by heating the furnace to a predetermined temperature, the silver plating layer and the copper plating layer of the sealing cup 26 and the adhesion layers 26b and 25b of the sealing material 25 are melted at high temperature, and the insulation is melted. It is diffused to the joint surface of the pipe 15 and the seal plate 9.

By melting the adhesive layer 26b of the sealing cup 26, the joints between the exhaust pipe 17 and the sealing cup 26 and the joints between the sealing cup 26 and the insulating pipe 15 are completely brought into close contact with each other.

Further, by melting the adhesion layer 25b of the sealing plate 25, the joints between the insulating pipe 15 and the sealing material 25 and the joints between the sealing material 25 and the sealing plate 9 can be brought into complete contact with each other.

Next, a sealing material 27 disposed on the outer surface of the seal plate 10 on the input side of the magnetron and a sealing material 2 for sealing the center support 5a and the side supports 5b on the outer surface of the insulator 12.
8 is the sealing material 2 on the large diameter side, as shown in Fig. 2 d and e.
The main material 7 is a metal layer 27a made of metal such as Kovar in a washer shape.

Further, the sealing material 28 on the small diameter side is mainly composed of a metal layer 28a formed from an iron plate in the shape of a washer.

Then, the entire surface of the sealing materials 27 and 28 of large and small diameters is sequentially plated with nickel-copper-silver at a rate of about 5-10-20 μm in the same manner as the sealing plate 25 and sealing cup 26 described above. 27b and 28b, respectively.

The sealing materials 27 and 28 configured in this way are similar to the sealing material 10.
A sealing material 27, a metallized insulator 12, a sealing material 28, a center support 5a and a side support 5b are passed through the sealing material 28, and the sealing material 27 is sequentially laminated on the outer surface of the
By inserting it into a heating furnace and heating it at a predetermined temperature, the silver plating layer and the copper plating layer of the adhesion layers 27b, 28b of the sealing materials 27, 28 are respectively melted at high temperature and diffused onto the bonding surfaces.

Then, the sealing plate 1
The joint portion between the outer surface of the insulator 12 and the upper end surface of the insulator 12 can be completely bonded.

Moreover, the bonding layer 28b of the sealing material 28 can completely adhere the joint portion between the outer surface of the insulator 12 and the peripheral surfaces of the center support 5a and side supports 5b that penetrate and protrude to the outer surface side. .

Moreover, in the experimental results, an extremely good sealing effect was obtained when the copper plating layer of the adhesion layers 25b to 28b was 5 μm or more, and the silver plating was 10 μm or more.

In addition, if a large amount of brazing material is required, it can be obtained by increasing the thickness of the copper plating layer and silver plating layer, but thicker plating layers require a longer time to diffuse to the bonding surface, which means that production Since the number of steps increases, it is preferable not to form a silver plating layer with a thickness of 100 μm or more.

In such cases, after applying nickel plating to the material such as the sealing material, copper-silver-copper-silver is coated with 20-40-20-40 plating.
If the plating layer is formed at a ratio of .mu.m, the time required for diffusion will not be long and sealing can be achieved in a short time.

In this way, metal parts such as the sealing materials 25, 27, 28 and the sealing cup 26 are coated with brazing material in advance by plating, laminated in sequence on the outer surfaces of the seal plates 9 and 10, and heated and bonded. According to this sealing method, the number of metal parts laminated on the outer surfaces of the sealing materials 9 and 10 is reduced from nine to five for each of the input and output parts, and the number of parts can be significantly reduced.

In addition, positioning in the pipe radial direction becomes easier, and the number of production steps can be significantly reduced.

In addition, in the above-mentioned example, the case where copper plating and silver plating were applied to the surface of the sealing material to form an adhesion layer as a brazing material was explained, but the present invention is not limited to this. When a copper-silver alloy is melted to form an adhesion layer on the entire surface of the sealant, or when a copper-silver alloy fine powder or a kneaded body with copper fine powder is kneaded with an organic binder, the sealant is It goes without saying that similar effects can be obtained even when the coating is applied to the surface to form an adhesion layer as a brazing material.

Although the case where the adhesive layers 25b to 28b of the sealing materials 25 to 28 are applied to the entire surface of the sealing material materials 25a to 28a has been described, the adhesive layers 25b to 28b of the sealing materials 25 to 28 are applied to the entire surface of the sealing material materials 25a to 28a. The same effect can be obtained even if the adhesive layer is formed by a technique such as plating spraying, and then the sealing materials 25 to 28 are formed by press molding.

In addition, good results can be obtained if the metal member to be sealed with the ceramic material is made of iron, nickel, copper, or an alloy containing these metals as the main components, at least in its surface portion. I can do it.

As explained above, the method for sealing metal parts and insulating members according to the present invention is suitable for metal parts whose surfaces are made of iron, nickel, or copper alone or alloys containing these metals as main components. In the case of bonding to ceramic by heating, a sealing material whose entire surface is coated with brazing material is interposed in advance between the metallized surface of the ceramic and the metal component, and the two are bonded by heating. Therefore, the number of components such as conventional ring-shaped or washer-shaped brazing materials can be completely eliminated, and waste during formation of brazing materials can be completely eliminated.

In addition, because the number of parts is significantly reduced, assembly becomes extremely easy, and the number of production steps and costs can be significantly reduced, among other excellent effects.

[Brief explanation of drawings]

Figures 1 a, b, and c are cross-sectional views of essential parts of an example of a conventional magnetron, and Figures 2 a to f are a case in which an embodiment of the method for bonding a metal part and an insulating member according to the present invention is applied to a magnetron. FIG. 1... Anode, 2... Cathode, 3...
...Bane, 4a, 4b... End shield,
5a・・・Center support, 5b・・・・・・
Side support, 6, 7...Magnetic pole, 8...
・・Work space, 9・・Seal plate, 9a・・・・
...Brim part, 10... Seal plate, 10a...
...Brim part, 11...Sealing plate, 12...
Insulator, 13, 14...Sealing material, 15...
...Insulating pipe, 16...Sealing cup, 17.
...Exhaust pipe, 18...Antenna, 19.
...Exhaust pipe cover, 20...Output section, 2
1-24...Rowing material, 25-28...
Sealing material, 25a to 28a...Metal layer, 25b to
28b... Adhesive layer.

Claims (1)

[Claims] 1. When bonding a metal part, at least the surface of which is made of iron, nickel, copper, or an alloy mainly composed of these metals, to a metallized ceramic by heating, Sealing of a metal part and an insulating member, characterized in that a sealing material whose entire surface is coated with brazing material is interposed between the metallized surface of the ceramic and the metal part, and the two are bonded by heating. Method. 2. The method of sealing a metal component and an insulating member according to claim 1, wherein the sealing material is a brazing material and is coated with at least one layer each of copper plating and silver plating. 3. A method of sealing a metal component and an insulating member according to claim 1, wherein the sealing material is interposed between the ceramic and the metal component having a coefficient of thermal expansion different from that of the ceramic. 4. A method of sealing a metal component and an insulating member according to claim 1 or 2, wherein the sealing material is coated with a copper-silver alloy as a brazing material. 5 In claim 1 or 2, the brazing material is a combination of a metal part and an insulating member made by kneading a fine powder of copper-silver alloy or a mixture of fine copper powder and fine silver powder into an organic binder. Sealing method.