JP2008270131A - Manufacturing method of stem for magnetron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a stem for a magnetron having a lead part, a metalized layer and a plated layer with a high yield. <P>SOLUTION: This manufacturing method of a stem for a magnetron having a stem body part formed of a ceramics sintered body, the metalized layer formed on the stem body part, and the lead part with the stem inserted therein is characterized by including processes of: preparing the stem body part formed of an alumina sintered body containing Mn; and applying Mo-Mn-based paste to a part of the stem body part, drying it at 50-100°C in a reductive atmosphere, and forming the metalized layer by baking it. Thereby a yield can be improved, and the joint strength of the metalized layer can be improved. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a method for manufacturing a magnetron stem used in microwave heating equipment such as a microwave oven.

Conventionally, as shown in FIG. 1 (Japanese Patent Publication No. 4-75618 (Patent Document 1)), there is a stem used for a cathode support portion of a magnetron. In the figure, reference numeral 1 denotes a stem body portion made of ceramics, and the stem body portion 1 is formed with a through hole 2 penetrating between both end faces. A washer joint surface 3 is formed on both side surfaces of the stem body 1, and an envelope joint surface 4 is formed on one side surface with a step around the washer joint surface 3. Lead portions 5 and 6 are inserted into the through holes 2 of the stem body portion 1 as cathode support rods.
Is brazed to the washer joint surface 3 of the stem body 1 by brazing with the washers 7 and 7 joined by brazing. The lead portions 5 and 6 are made of Mo having excellent high temperature strength because they are used at high temperatures. A metal envelope 8 is joined and sealed to the envelope joint surface 4 of the stem body 1 by brazing. The washer joint surface 3 and the envelope joint surface 4 of the stem body 1 are provided with a metallized layer 9 for joining the washer 7 and the metal envelope 8.
And 10 are formed, and the surface of the metallized layer is brazed. Further, since the joint between the lead parts 5 and 6 and the washer 7 serves as a sealing part for the outside air of the stem body 1, the brazing material paste is used for brazing the lead parts 5 and 6 and the washer 7. In order to improve the adhesion and improve the sealing property, Ni plating is applied to the surface. In the figure, 11 is a cathode filament, and 12 and 13 are end shields that hold the cathode filament 11 to the lead portions 5 and 6.
The stem body 1 was made of an alumina sintered body, and the metallized layer 9 was made of Mo alone. Mo metallized layer has low bonding strength with Ni plating.
-Mn metallization layer is used (Japanese Patent Laid-Open No. 2002-56783 (Patent Document 2)
)). This increases the bonding strength between the metallized layer and the Ni plating, and further increases the bonding strength and confidentiality between the Ni plating layer and the washer, thereby improving the sealing effect.
As described above, the metallized layer is improved from Mo to Mo-Mn, but the bonding strength is improved, but the metallization process becomes complicated and the yield is not improved sufficiently. In addition, Ni plating is essential for improving the bondability with the washer, but the plating yield has not been sufficiently improved.

Japanese Examined Patent Publication No. 4-75618 JP 2002-56783 A

The present invention relates to a method for manufacturing a stem for a magnetron with a lead portion in which a Mo-Mn metallized layer is formed on a stem body portion and Ni is plated thereon, and the yield is improved, and the stem body portion, metallized layer, metallized layer and Ni The present invention provides a manufacturing method capable of improving the bonding strength of the plating layer.

The method for manufacturing a magnetron stem according to the present invention includes a stem main body portion made of a ceramic sintered body, a metallized layer formed on the stem main body portion, and a magnetron stem manufacturing method having a lead portion inserted through the stem. A step of preparing a stem main body portion comprising an alumina sintered body to be contained, by applying Mo-Mn paste to a part of the stem main body portion, drying at 50 to 100 ° C. in a reducing atmosphere, and then firing. The method includes a step of forming a metallized layer, a step of inserting and fixing a lead portion to the stem body, and a step of performing Ni plating on the metallized layer.
Moreover, it is preferable that the color of a stem main body changes during the process of forming a metallized layer. Moreover, it is preferable that it is an alumina sintered compact whose Mn content is 1-5 mass%.
The Mo-Mn paste is a mixture of Mo powder having an average particle size of 0.5 to 10 μm and Mn powder having an average particle size of 0.5 to 10 μm for 40 hours or more, and then mixed with a binder. It is preferable that it is prepared.
Moreover, it is preferable that the process of performing said Ni plating is barrel type electrolytic plating. Also,
When performing the barrel electrolytic plating, it is preferable to mix a metal dummy member in the plating bath. Moreover, it is preferable that 5-30 vol% of the metal dummy members are mixed with respect to the total volume of the magnetron stem. The metal dummy member preferably has an eyelet shape.

According to the present invention, the yield of the magnetron stem can be greatly improved.
In addition, since the bonding strength of the metallized layer and the Ni plating layer can be improved, the reliability of the stem can be improved.

The method for manufacturing a magnetron stem according to the present invention includes a stem main body portion made of a ceramic sintered body, a metallized layer formed on the stem main body portion, and a magnetron stem manufacturing method having a lead portion inserted through the stem. A step of preparing a stem main body portion comprising an alumina sintered body to be contained, by applying Mo-Mn paste to a part of the stem main body portion, drying at 50 to 100 ° C. in a reducing atmosphere, and then firing. The method includes a step of forming a metallized layer, a step of inserting and fixing a lead portion to the stem body, and a step of performing Ni plating on the metallized layer.
First, the stem main body portion made of a ceramic sintered body is an alumina sintered body containing Mn. The Mn content is preferably in the range of 1 to 5% by mass. More preferably 1.5 to 3.5
% By mass. By containing Mn, the bonding strength with the Mo-Mn metallized layer can be improved. If the Mn content is less than 1% by mass, the effect of inclusion cannot be obtained. On the other hand, 5
If it exceeds mass%, the alumina sintered body may not be densified. Moreover, although the size of a stem main-body part is arbitrary, the cylinder shape about 10-20 mm in diameter and 7-15 mm in length is mentioned.
Further, the addition of the Mn compound also has the effect of coloring the alumina sintered body brown. Since the brown alumina sintered body turns pink in the metallization process described later, the degree of completion of the metallization process can be confirmed visually.

Mn is added to an alumina (aluminum oxide) powder as a Mn compound such as manganese oxide or manganese carbonate, and an alumina sintered body is obtained by molding and sintering. It is preferable to provide a hole for inserting the lead portion during molding and a convex portion (step) for forming the metallized layer.
In addition to Mn, a sintering aid may be added to the alumina sintered body. Examples of the sintering aid include silicon oxide (SiO ₂ ), magnesium oxide (MgO), calcium oxide (CaO), and the like. These include at least one of Si, Mg, and Ca in total in terms of a single metal element. It is preferable to add 10 mass%.
The added sintering aid reacts with the Mn compound to produce MnO—SiO ₂ —MgO, MnO.
A grain boundary phase composed of a glass phase such as —SiO ₂ or MnO—MgO is formed to densify the alumina sintered body. Further, since the glass phase enters the voids of the Mo—Mn metallized layer, the metallized layer can be strengthened and the bonding strength can be improved. In the present invention, since Mn is contained in the alumina sintered body, familiarity with the Mo-Mn metallized layer is good.

Next, a Mo—Mn-based paste is applied to a part of the stem main body, and 50 to 50 in a reducing atmosphere.
After drying at 100 ° C., a step of forming a metallized layer by firing is performed.
The Mo-Mn paste is a mixture of Mo powder and Mn powder with an organic binder.
The organic binder is not particularly limited as long as it is burned off by a drying process or a baking process. The Mn powder may be a Mn compound powder such as MnO. A preferred example is ethyl cellulose.
The Mo-Mn paste is prepared by adjusting Mo powder having an average particle size of 0.5 to 10 μm and an average particle size of 0.1 μm.
It is preferable that 5-10 μm Mn powder is prepared by mixing each with a binder after crushing treatment for 40 hours or more. The ratio of Mo to Mn is 4 to 12% by mass, preferably 6 to 8% by mass when the total of Mo and Mn is 100% by mass.

When the Mo—Mn metallized layer is formed, voids are easily formed in the metallized layer. The gap is mainly formed by a gap formed when the organic binder is burned off. However, if the particle size of the Mo powder and the Mn powder is large, the gap is likely to increase. Therefore, it is necessary to prepare fine and uniform Mo powder and Mn powder. For that purpose, it is preferable to pulverize the Mo powder having an average particle size of 0.5 to 10 μm and the Mn powder having an average particle size of 0.5 to 10 μm for 40 hours or more. M
By crushing o powder and Mn powder separately, a more uniform powder is obtained. The crushing time is preferably 40 hours or longer. Since Mo is a heavy metal with a high specific gravity, if it is attempted to crush in a short time, the load on the crusher is large, reducing the life of the crusher and, in turn, increasing the production cost. Also, since Mn is an active metal, there is a risk of ignition if it is also crushed in a short time. The upper limit of the crushing time is not particularly limited, but if the time is too long, the production time becomes longer, so 100 hours is taken as a guide. More preferably, the crushing time is set to 60 to 80 hours using Mo powder and Mn powder having an average particle diameter of 1 to 4 μm. Crushing may be either dry or wet, but the wet method can suppress the ignition characteristics of Mn. Moreover, it is preferable to dry the Mo powder and Mn powder after crushing. The crushing treatment may be performed using a hard medium such as an alumina ball.
After crushing the Mo powder and the Mn powder, a predetermined amount of the Mo powder and the Mn powder is weighed and mixed with the organic binder. After mixing with the organic binder, it is preferable to use a mixing method with a high load such as a triple roll after mixing in a container.
Since the Mo-Mn paste prepared in this way is uniformly mixed with Mo powder and Mn powder, and further has an appropriate viscosity, it does not easily cause a problem of flowing down even when applied to the stem body. Therefore, even if the paste is applied not only to the front surface but also to the back surface, the paste does not flow down, so that all metallized layers can be dried in a single drying step.

In addition, the application of the Mo—Mn paste increases the mass productivity by the screen printing method. The coating thickness is preferably 10 to 40 μm. If the coating thickness is less than 10 μm, the thickness of the Mo layer varies after the metallized layer is formed, and the bonding strength is reduced. On the other hand, if it exceeds 40 μm, no further effect can be obtained.
Moreover, a drying process is 50-100 degreeC in a reducing atmosphere, Preferably it is 50-80 degreeC. The reducing atmosphere is preferably a hydrogen-containing atmosphere, more preferably an inert gas (argon, nitrogen, etc.) containing 10 to 20 at% hydrogen. The drying time is 5 to 30 minutes, preferably 10 to 20 minutes.
By drying in a reducing atmosphere, the Mn oxide in the alumina sintered body and the Mo-Mn paste is reduced. When the Mn oxide is reduced, the reaction of forming a glass phase with other oxides, for example, a sintering aid such as SiO 2 and MgO, becomes significant in the firing step, and the glass phase easily enters the voids in the metallized layer. Become. As a result, the bonding strength of the metallized layer is improved.

A baking process is performed after a drying process. The firing temperature is 1350 to 1550 ° C., preferably 1400
˜1480 ° C. The firing time is preferably in the range of 30 minutes to 5 hours. The atmosphere is preferably a reducing atmosphere.
The firing time is preferably 1 hour or longer. When it is fired for 1 hour or longer, it is easy to form a deposited layer in which the glass phase in the alumina sintered body is uniformly deposited on the surface. The deposited layer deposited on the surface of the alumina sintered body is deposited between the alumina sintered body and the Mo-Mn metallized layer and enters the voids of the metallized layer. Therefore, the metallized layer is densified and the bonding strength is improved.
Further, it is preferable to circulate a reducing atmosphere during firing. When it is fired in a reducing atmosphere, the grain boundary phase is mainly reduced. The reduced oxygen reacts with hydrogen to become water. Firing atmosphere is 13
Since it is a high temperature of 50 ° C. or higher, it becomes water vapor, but if too much water vapor remains, it adversely affects the metallized layer, so it is preferable to circulate a reducing atmosphere to remove the water vapor.

The flow rate of the reducing atmosphere gas is 100 L / min (= liter / min) or more, preferably 100 to 300 L / min, and more preferably 130 to 250 L / min. If the flow rate of the reducing atmosphere gas is too small, it is difficult to remove water vapor generated by the reduction reaction. on the other hand,
If it exceeds 300 L / min, a load is imposed on the management of the supply device. Also, if the flow rate is too large, the reaction between the reducing atmosphere and the ceramic body tends to vary.
Moreover, the baking furnace which performs a baking process may be a continuous furnace or a batch furnace. Moreover, it is preferable to use a Mo board to mount the stem body. Moreover, when performing a metallization process by continuous operation | movement of a baking furnace, it is preferable to manage the flow volume of reducing atmosphere gas.
When the metallized layer is completed, the color of the alumina sintered body changes. For example, what was brown turns into pink. This indicates that the Mn oxide in the alumina sintered body has been reduced. When the Mn oxide is reduced, the reaction with the other sintering aid proceeds and the effect of the glass phase entering the voids of the metallized layer is obtained. In particular, when exposed to a high temperature during the baking process, the glass phase is deposited on the surface side, so that the gap between the metallized layers is filled. Further, since the color change is accompanied, the progress of metallization can be visually confirmed, so that it is easy to confirm the presence or absence of metallization failure. In addition, the above-mentioned pink color shall include from a beautiful pink color to a cloudy pink color (red bean color).

After the metallization process is completed, a process of inserting the lead portion is performed. The lead portion is preferably made of a refractory metal such as Mo. The length of the lead portion is arbitrary.
After inserting the lead part, fix it with brazing material. The brazing material is preferably an Ag-based brazing material. Examples of the Ag-based brazing material include Ag, Ag-Cu, and Ag-Sn. The brazing temperature is 500 to 900 ° C. When the magnetron stem is incorporated into the magnetron, the stem portion of the magnetron generally rises only to a temperature of 400 ° C. or lower, so it is preferable to use a brazing material having a melting point of 500 ° C. or higher.
After fixing the lead portion, a step of applying Ni plating on the metallized layer is performed. The thickness of the Ni plating is preferably in the range of 1 to 5 μm.
Moreover, in order to improve mass productivity, it is preferable to perform the process of performing Ni plating by barrel type electrolytic plating. The barrel type can uniformly mix the electrolyte and the stem with the lead in the rotating container, so that 1000 or more stems can be plated at a time. Moreover, since alumina is an insulator, it is not directly Ni-plated. The metallized layer, which is a conductor, and the lead portion are Ni-plated.

Moreover, in order to improve the yield of Ni plating, it is preferable to mix a metal dummy member in the plating bath when performing the barrel type electrolytic plating. When a metal dummy member is mixed, the electroconductivity of the electrolytic solution is improved, so that the plating efficiency is increased. Moreover, if there is a metal dummy member, it can be used as a cushion and the stem body portions can be prevented from colliding and being damaged. Therefore, the yield of Ni plating is improved and the bonding strength of Ni plating is also increased.
The metal dummy member is preferably smaller than the stem main body, and preferably has a (volume of metal dummy member / volume of stem main body) ratio of 0.01 to 0.2. If the ratio (volume of metal dummy member / volume of stem main body) is less than 0.01, the metal dummy member is too small, and a large number of dummy members must be introduced. Moreover, if it is too small, problems such as being caught between the lead parts also occur. On the other hand, if it exceeds 0.2, the proportion of the dummy member in the electrolytic solution becomes too large, and the amount of stems that can be processed decreases.
Moreover, it is preferable that 5-30 vol% of metal dummy members are mixed with respect to the total volume of the stem with a lead. If it is less than 5 vol%, the effect of mixing cannot be obtained sufficiently, and 30 vol.
If% is exceeded, the amount of stems that can be processed at one time decreases.

Further, the shape of the metal dummy member may be a shape as shown in FIGS. 2 (a) and 2 (b), FIG. 3, and FIG. FIG. 2A is a cross-sectional view of a metal dummy member having an eyelet shape on one side, FIG.
(B) is an oblique view of a metal dummy member having an eyelet shape on one side. 3 is a cross-sectional view of a metal dummy member having eyelet shapes at both ends, and FIG. 4 is a cross-sectional view of a metal dummy member having no eyelet shape. In the drawing, d1 represents the outer diameter of the eyelet part, d2 represents the inner diameter of the main body part of the dummy member, and L represents the length of the dummy member.
The shape of the metal dummy member may vary from a cylindrical shape shown in FIG. 4 to a cylindrical main body portion shown in FIGS. 2 and 3 provided with an eyelet portion. In the present invention, it is not limited to a cylinder, and may be a quadrangular prism, a polygonal column, a triangular prism, a triangular pyramid, or a spherical shape. In addition,
It is preferable that there is no angular portion such as a cylinder or a sphere because the stem is not damaged.
Further, the shape of the metal dummy member is preferably a metal dummy member volume / stem main body volume) ratio of 0.01 to 0.2, as described above. For example, d1 is 2 to 5 mm and d2 is 1 to 3 mm and L is 3 to 6 mm.
In addition, examples of the metal constituting the dummy member include simple metals such as iron and stainless steel and alloys. The temperature of the electrolytic bath is a warm bath of about 40 to 70 ° C., and the plating time is about 30 to 60 minutes.

With such a barrel electrolytic plating method, 1000 or more at a time, or even 2500
One or more stems with leads can be processed, and the processing time is 30 to 60 minutes, so that the yield of Ni plating can be 90% or more, and further 95% or more. The number of stems that can be processed at one time depends on the size of the electrolytic bath, the size of the stem, etc., but even if 2500 to 3500 stems with leads are processed, the yield can be increased to 90% or more, and more than 95%. .
The above magnetron stem manufacturing method greatly improves the yield, and greatly improves the yield to 90% or more even after complicated processes such as metallization layer formation, lead fixation, and Ni plating formation. can do. In addition, the bonding strength of the metallized layer and Ni plating can be improved. Therefore, it is possible to manufacture a highly reliable magnetron with good sealing properties when mounted on the magnetron.
(Example 1, Comparative Examples 1-4)
The effect of this embodiment will be confirmed using a process for manufacturing a magnetron stem having a shape as shown in FIG. First, an alumina sintered body having a diameter of 15 mm and a length of 10 mm was used as the stem body, and a convex portion (step) for forming a metallized layer was provided at the tip.

Step A1: A stem body portion made of an alumina sintered body to which Mn oxide, silicon oxide, and magnesium oxide are added as a sintering aid is prepared. The Mn content in the sintered body is 3.0 wt% in terms of Mn alone.
1.9 wt% in terms of Si simple substance and 2.4 wt% in terms of Mg simple substance. Moreover, when the component of the grain boundary phase was subjected to X-ray diffraction, it was found that no peak was detected and the glass phase was a glass phase.
Process A2: The same thing as process A1 was prepared except not containing Mn.
Step B1: Mo powder having an average particle diameter of 2 μm and Mn powder having an average particle diameter of 2 μm were each crushed by a ball mill for 70 to 80 hours. Then, it dried and mixed ethyl cellulose as Mo powder, Mn powder, and a binder. After mixing for 5 to 15 hours by the single roll method, mixing was performed for 10 to 25 hours by the three roll method. Mo containing 7% by mass of Mn by this process
-A Mn paste was prepared.
Step B2: A Mo—Mn paste was prepared using the same step as Step B1 except that the crushing treatment was not performed.

Step C1: Screen-printed Mo-Mn paste at a predetermined position of the stem body with a coating thickness of 20 μm, and 65 to 75 ° C. × 1 under a reducing atmosphere (inert atmosphere containing 15 vol% hydrogen)
Dry for 0-20 minutes. The flow rate of the reducing atmosphere gas was set in the range of 170 to 220 L / min.
Step C2: The same drying step as Step C1 was performed except that drying was performed in the air.
Step D1: 1400 to 1450 under reducing atmosphere (inert atmosphere containing 15 vol% hydrogen)
A metallized layer was formed by heat treatment at 2 ° C. for 2 to 3 hours. The flow rate of the reducing atmosphere gas was set in the range of 170 to 220 L / min.
Step D2: A metallized layer was formed by the same method as in Step D1, except that heat treatment was performed in the air.
Step E1: The lead part made of Mo was inserted and brazed with an Ag-based brazing material.

Step F1: A metal dummy member whose main component is iron so that the volume ratio is 10 vol% with respect to 3000 stems with leads (the shape shown in FIG. 2 is provided with an eyelet part and d1 is 2 m)
m, d2 is 1 mm, L is 4 mm), and barrel type electrolytic plating is performed at 40 to 60 ° C.
X Performed for 30 to 50 minutes.
Step F2: Barrel-type electrolytic plating was performed in the same manner as in Step F1, except that no metal dummy member was used.
The manufacturing methods according to the examples and comparative examples were performed by combining the respective steps, and the yield and the bonding strength of the metallized layer were obtained. For the yield, 3000 magnetron stem main bodies were prepared, and it was finally determined whether or not the magnetron stem could be manufactured. Also, the joint strength of the metallized layer is brazed with a Kovar plate on the Ni-plated metallized layer, and its tensile strength (
kgf) was determined. 100 operations were performed and the average value was shown. Moreover, the lowest joint strength is shown as the lowest value. Moreover, the presence or absence of the change of the color of an alumina sintered compact was confirmed in the metallization process (process C-process D). The results are shown in Table 1.

Example 1: Step A1 → Step B1 → Step C1 → Step D1 → Step E1 → Step F1
Comparative Example 1: Step A2, Step B1, Step C1, Step D1, Step E1, Step F1
Comparative Example 2: Step A1 → Step B2 → Step C2 → Step D1 → Step E1 → Step F1
Comparative Example 3: Step A1 → Step B1 → Step C1 → Step D1 → Step E1 → Step F2
Comparative Example 4: Step A1 → Step B1 → Step C1 → Step D2 → Step E1 → Step F1

As can be seen from the table, the method for manufacturing the magnetron stem according to this example has a high yield. Also, a high value of the bonding strength was obtained. Although not shown in the table, the maximum value of the bonding strength of the magnetron stem of Example 1 was 102 kgf.
On the other hand, although the comparative example 1 had a high apparent yield, since the alumina sintered body did not contain Mn, the bonding strength of the metallized layer was low. In Comparative Example 2, since the adjustment with the base and the drying process were insufficient, the bonding strength of the metallized layer was low.
Moreover, since the comparative example 3 did not use the metal dummy member at the plating process, there were many plating defects and the yield fell. Further, in Comparative Example 4, since the metallization process was not performed in a reducing atmosphere, the Mn oxide of the alumina sintered body was not reduced, so that the glass phase moved little and the bonding strength of the metallized layer was lowered.
(Examples 2 to 5)
A magnetron stem was manufactured in the same manner as in Example 1 except that Step B1 was changed as shown in Table 2, and the same measurement was performed. The results are shown in Table 2.

As can be seen from the table, it was found that Example 4, which has a short crushing time, and Example 5, in which the Mo powder and Mn powder are larger than the preferred range, have a tendency to decrease the yield and contact strength. Although not shown in the table, any change in the color of the alumina sintered body was confirmed in the metallization step. The stem body before metallization was brown, but after metallization it was pink (red bean color).
(Examples 6 to 8)
A magnetron stem was manufactured in the same manner as in Example 1 except that the step F1 was changed as shown in Table 3, and the same measurement was performed. The results are shown in Table 3.

As can be seen from the table, when the addition amount of the metallic dummy member is as small as less than 5 vol%, the effect of improving the electroconductivity is small, so the effect of improving the plating failure is small. In addition, a short plating time as in Example 7 also causes a failure.
On the other hand, when Example 8, Example 9, and Example 1 are compared with each other and arranged in order of good yield, Example 8, Example 1, and Example 9 are obtained. From this comparison, it can be said that the yield is improved when the metal dummy member has the eyelet portion. This is considered to be because the eyelet part serves as a cushion and can suppress the collision between the stems.
(Examples 10 to 13)
Next, using the same method as in Example 1, the amount of stem to be processed was changed as shown in Table 4, and the yield was measured. The results are shown in Table 4.

As can be seen from the table, a high yield was confirmed even when the number of stems increased.
As described above, the method for manufacturing the magnetron stem according to the present example has a good yield and the joint strength of the metallization layer of the stem obtained is high. Therefore, a highly reliable magnetron stem can be manufactured, and as a result, the reliability of the magnetron using the stem can be improved.

Sectional drawing which shows an example of the magnetron using the stem for magnetrons of this invention. The figure which showed an example of the metal dummy members of this invention. The figure which showed another example of the metal dummy members of this invention. The figure which showed another example of the metal dummy members of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stem main-body part 2 ... Through-hole 3 ... Washer joint surface 4 ... Envelope joint surface 5, 6 ... Lead part 7 ... Washer 8 ... Metal envelope 9, 10 ... Metallization layer 11 ... Cathode filaments 12, 13 ... End shield

Claims (8)

In a method for manufacturing a stem for a magnetron having a stem body portion made of a ceramic sintered body, a metallization layer formed on the stem body portion, and a lead portion inserted through the stem,
Preparing a stem body portion made of an alumina sintered body containing Mn,
Mo-Mn paste is applied to a part of the stem body, and 50 to 100 ° C in a reducing atmosphere.
A step of forming a metallized layer by firing after drying with
Inserting and fixing the lead part to the stem body part,
Applying Ni plating on the metallized layer;
A method for manufacturing a magnetron stem, comprising: The stem body color changes during the step of forming the metallized layer.
The manufacturing method of the stem for magnetrons of description. 3. The method for producing a magnetron stem according to claim 1, wherein an alumina sintered body having a Mn content of 1 to 5% by mass is used. The Mo—Mn paste is composed of Mo powder having an average particle size of 0.5 to 10 μm and an average particle size of 0.5.
The magnetron according to any one of claims 1 to 3, wherein the powder is prepared by crushing 10 to 10 µm of Mn powder for 40 hours or more and then mixing with a binder. Stem manufacturing method. The method for manufacturing a magnetron stem according to any one of claims 1 to 4, wherein the step of applying Ni plating is barrel electrolytic plating. 6. The method of manufacturing a magnetron stem according to claim 5, wherein a metal dummy member is mixed in the plating bath when performing the barrel electrolytic plating. The method of manufacturing a magnetron stem according to claim 6, wherein the metal dummy member is mixed in an amount of 5 to 30 vol% with respect to the total volume of the magnetron stem. The method for manufacturing a magnetron stem according to claim 6, wherein the metal dummy member has an eyelet shape.

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