JPH0268834A - Manufacture of magnetron - Google Patents

Abstract

PURPOSE:To arrange the constitution such that there is no fear of electrical short circuit occuring at each part with the amount of solder material required at minimum by providing a pair of connecting parts, having the length nearly same as the width of the ring-shaped recess of a ceramic stem, in a body with a peripheral ring part, and using united solder material as the solder material. CONSTITUTION:Relay metal plates 54 and 55 are put on the island parts 64 and 65 of united solder material 60 and a metallic vessel 40 is put on a peripheral ring part 61. Further, external connection leads 44 and 45 are made to pierce the through holes 42 and 43 of a ceramic stem 41, the through hole 67 and 68 bored in the island parts 64 and 65, and the through holes of realy metallic plates 54 and 55, respectively. Also, cathode supporting bars 25 and 26 are made to pierce and engage with through holes 69 and 70 bored in island parts 64 and 65, through holes of the relay metallic plates 54 and 55 and holes 50 and 51 for engagement of the cathode supporting bars, respectively. And while holding it with the ceramic stem 41 down and with the metallic vessel 40 up, it is let pass a hydrogen furnace so as to airtightly solder each part at the same time. Hereby, there is no fear of each part causing electric short circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method of manufacturing a magnetron for a microwave oven.

(Conventional technology) The conventionally used magnetron for microwave ovens is
It is constructed as shown in FIG. 3, and numeral 35 is an anode structure. A plurality of vanes 37 are arranged radially inside an anode cylinder 36 which is a part of this anode structure 35, and every other vane 37 is connected by two large and small strap rings 38. Furthermore, a coiled cathode 21 is disposed along the axis of the anode cylinder 36 in the electron action space formed by the free end of each vane 37, and both ends of the coiled cathode 21 are connected to a pair of end hats 22 (for convenience, one end hat is (not shown). Each end hat 22 has a cathode support rod 2 extending in the tube axis direction.
5.26.

A pole piece 39 is attached to one end of the anode cylinder 36.
A cylindrical metal container 40 constituting a part of the vacuum container is hermetically sealed to the metal container 40, and a ceramic stem 41 is hermetically sealed to the open end of the metal container 40.

This ceramic stem 41 is constructed as shown in FIGS. 3 to 7, and is generally cylindrical in shape and has a pair of through holes 42 and 43 through which external connection leads (to be described later) pass. Further, on one surface, an elongated external connection lead fitting groove 52.53 is formed which is continuous with the through hole 42.43, has the same width as the through hole 42.43, and extends in opposite directions.

Furthermore, as is clear from FIG. 7, the ceramic stem 4
A ring-shaped recess 46 is formed on the side facing the vacuum area of 1, and the inner surface of this ring-shaped recess 46 is connected to the relay metal plate (
There are two approximately semicircular metal plate joining surfaces 47 on the left and right for joining (described later), a central groove 48 is formed between them to provide insulation between the filaments, and the outer peripheral surface is the metal container 40. It is used as a metal container joining surface 49 for joining. Both of these joint surfaces 47 and 49 are formed so as to be located on the same plane perpendicular to the central axis. Also, a cathode support rod fitting hole 50.51 having a predetermined depth is bored diagonally with the through hole 42.43.

Note that the depth of the ring-shaped recess 46 is deeper than the depth of the central groove 48 of the ceramic stem 41.

Also, as is clear from Fig. 6, the relay metal plates 54, 55
are respectively joined to the metal plate joining surface 47, and the quad support rods 25.26 are fixed to the cathode support rod fitting holes 50.51 through the relay metal plates 54.55. The external connection leads 44 and 45 connect to the ceramic stem 41.
It passes through the through hole 42.43 and is fixed to the relay metal plate 54.55.

Now, during manufacturing, the metal plate joint surface 47 and the metal container joint surface 4 located on the same surface of the ceramic stem 41 are
Molybdenum (Mo)-manganese (M n
) Apply the paste. After drying the paste, 1400℃
The material is sintered in an inert gas heating furnace to form a so-called metallized layer.

Next, the relay metal plates 54, 55 and the metal container 40 are hermetically soldered to the corresponding joint surfaces 47, 49 using silver solder. The material for these relay metal plates 54 and 55 is a metal that has a similar coefficient of thermal expansion to the ceramic stem 41 and is easily soldered through a metallized layer, such as Kovar (trade name) or Fe-Ni-Cr alloy. is used.

A pair of external connection leads 44, 45 made of metal rods such as steel or iron are passed through through holes formed in each of the relay metal plates 54, 55, and are inserted into the through holes. Hermetically sealed by soldering. These external connection leads 44 and 45 are connected to the through holes 4 of the ceramic stem 41, respectively.
2.43, and as is clear from Figure 3,
Bent portions 44a and 45a are formed at positions corresponding to the vicinity of the end of the ceramic stem 41. These bent portions 44a and 45a form concave grooves 52.5 for fitting external connection leads.
3, thereby preventing rotation in the circumferential direction.

Each cathode support rod 25, 26 is also connected to each relay metal plate 5.
The ceramic stem 41 is inserted into the adjacent through hole formed in 4.55 and soldered, and the lower end that extends further downward is the ceramic stem 41.
Each cathode support rod fitting hole 50 of a predetermined depth formed in
．． 51, and is mechanically and stably locked and positioned.

In this way, each cathode support rod 25.26 and each external connection lead 44.45 are connected to the relay metal plate 54.55, respectively.
electrically connected via.

(Problem to be Solved by the Invention) However, in the conventional manufacturing method as described above, the joint surfaces 4 corresponding to the relay metal plates 54, 55 and the metal container 40, respectively.
It is necessary to insert separate silver solders between the 7.49 and 49, which has the disadvantage of poor workability.

On the other hand, a technique for increasing assembly efficiency by integrating ring-shaped brazing fillers having different diameters is disclosed, for example, in Japanese Patent Publication No. 36794/1983. However, according to the technology in the same publication,
A spacer that connects a plurality of ring-shaped brazing materials may cause an electrical short circuit in the soldered portion or use an excess amount of brazing material, which is undesirable.

This invention solves the above-mentioned inconveniences, and by using an integral brazing material, it significantly improves the workability of brazing the ceramic stem part, and also improves reliability with the minimum necessary brazing material. The object of the present invention is to provide a method for manufacturing a magnetron having good soldered joints.

[Structure of the Invention] (Means for Solving the Problems) This invention provides an outer ring portion having a diameter corresponding to the diameter of the open end of a metal container, and a ring-shaped recess of a ceramic stem that is integrated with the outer ring portion. a pair of connecting parts having a length approximately the same as the width of the ceramic stem, and a pair of island-like parts connected to the connecting parts and having two pairs of through holes that also serve as positioning and sandwiching a slit that matches the central groove of the ceramic stem. This is a method for manufacturing a magnetron, in which an integral brazing material having the following properties is used, the integral brazing material is placed between a laminate stem, a relay metal plate, and a metal container, and these, a cathode support rod, and an external connection lead are simultaneously soldered.

(Function) According to the present invention, since an integral brazing filler metal is used as the brazing filler metal, it is efficient with the minimum necessary amount of brazing filler metal, and there is no fear of electrical short-circuiting of various parts, and workability is improved. Significantly improved.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Since the magnetron obtained by the manufacturing method of the present invention is also as described above, each of the figures used in the above description will be used again.

In the manufacturing method according to the present invention, an integral brazing filler metal is used in brazing each component, unlike the conventional method. First, this integral brazing filler metal will be described.

That is, the integral brazing material 60 used in the present invention is constructed as shown in FIG. 2, and is made of silver solder, and reference numeral 61 is an outer ring portion. A pair of connecting portions 62.63 are formed integrally with the outer ring portion 61 in the radial direction inside the outer circumferential ring portion 61, and a pair of island-shaped portions are integrally connected to the pair of connecting portions 62.63. 64 and 65 are provided across the slit 66. Two pairs of through holes 67 to 70 which also serve for positioning are bored in the island portions 64 and 65.

Incidentally, reference numeral 71 is a space, which includes a slit 66 and a through hole 67.
This is the part where the plate-shaped brazing filler metal 2 was removed by press punching along with 70.

In this case, the outer ring portion 61 substantially corresponds to the four metal container joint surfaces, the connecting portions 62, 63 are located above the ring-shaped recess 46 formed in the ceramic stem 41, and the island portions 64, 63 are located above the ring-shaped recess 46 formed in the ceramic stem 41. 65, of course, approximately corresponds to the metal plate joining surface 47 and the relay metal plates 54 and 55. In addition, the island-shaped portion 64
．． The two pairs of through holes 67 to 70 drilled in the ceramic stem 41 correspond to the through holes 42.43 formed in the ceramic stem 41 and the cathode support rod fitting holes 50.51, and the quad support rods 25.26 It also has the function of positioning the external connection leads 44, 45 and thereby positioning the outer peripheral ring portion 61 of the integral brazing material 60.

Furthermore, the slit 66 corresponds to the central groove 48 formed in the ceramic stem 41.

To manufacture a magnetron using such an integral brazing material 60, first, a ceramic stem 41 shown in FIG.
Molybdenum (Mo)-manganese (Mn) paste is applied to the entire surface of the metal plate joint surface 47 and the metal container joint surface 49, which are located on the same surface (also corresponds to FIG. 7).

After drying the paste, it is placed in an inert gas heating furnace at about 1400° C. and sintered to form a so-called metallized layer.

Next, an integral brazing material 60 is placed on this metallized layer. Then, the relay metal plate 54.55 is placed on the island portion 64.65 of this integral brazing material 60, and the metal container 40 is placed on the outer peripheral ring portion 61, respectively.

Furthermore, the external connection leads 44.45 are passed through the through holes 42.43 of the ceramic stem 41, the through holes 67.68 drilled in the island portion 64.65, and the through holes of the relay metal plate 54.55, respectively. let

In addition, the cathode support rods 25, 26 are connected to the island-shaped portions 64, 6, respectively.
Through hole 69.70 drilled in 5 and relay metal plate 54.5
5 and the cathode support rod fitting holes 50 and 51.

In this way, the ceramic stem 41 is held on the lower side and the metal container 40 is placed on the upper side using a holding jig (not shown), and the parts are simultaneously passed through a hydrogen furnace and hermetically soldered together.

[Effects of the Invention] As explained above, according to the present invention, the connecting portion of the brazing material on the ring-shaped recess of the ceramic stem does not flow into the ring-shaped recess, but flows toward the metal container and the relay metal plate. Since the current is shunted, it is useful for brazing, and there is no risk of electrical short circuits occurring between various parts.

In addition, an integral brazing material is used as the brazing material, and the through hole in the island-shaped portion also serves as positioning of the lead, which significantly improves workability.

Furthermore, since the depth of the central groove 48 is relatively shallow, if there is a brazing material on this central groove 48, there is a possibility that it will melt and this central groove 48 will create an electrical short circuit. With this invention, there is no such risk. On the other hand, since the ring-shaped recess on the outer periphery is relatively deep, even if the connecting portion of the brazing material melts, it is absorbed by the outer ring or island-like portion and does not drip or flow into the ring-shaped recess.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, FIG. 2 is a plan view showing an integral brazing material used therein, and FIG. 3 is a longitudinal sectional view showing a magnetron obtained by the manufacturing method of the present invention. FIG. 4 is a top view of the main part, and FIGS. 5 to 7 are perspective views of the main part. 21... Cathode, 25.26... Cathode support rod, 35-... Anode structure, 4o... Metal container, 41
3. . Ceramic stem, 42.43... Through hole, 44.4
5... External connection lead, 46... Ring-shaped recess, 4
8...Central groove, 54.55...Relay metal plate, 6o.
... Integral brazing material, 61 ... Outer ring part, 62.63
... Connecting portion, 64.65... Island-shaped portion, 66... Slit, 67-70... Through hole. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure Figure 1

Claims (1)

[Scope of Claims] A cylindrical metal container that is hermetically sealed to a part of the anode structure and constitutes a part of the vacuum container; a cathode disposed at the center axis of the anode structure; and a cathode supported at the tip. a cathode support rod supporting the cathode support rod, the open end of the metal container being hermetically soldered to the metal container having a ring-shaped recess and a central groove connected to the ring-shaped recess on the side surface of the metal container; A ceramic stem having a through hole, a relay metal plate soldered to the cathode side surface of the ceramic stem, and an external connection lead inserted through the through hole of the ceramic stem and soldered to the relay metal plate. A method for manufacturing a magnetron comprising: an outer ring portion having a diameter corresponding to the diameter of the open end of the metal container; and a pair of connecting portions integrated with the outer ring portion and having a length substantially the same as the width of the ring-shaped recess. and a pair of island-like parts that are integrally connected to this connecting part and have two pairs of through holes that also serve as positioning, and that sandwich a slit that coincides with the central groove. 1. A method for manufacturing a magnetron, which comprises disposing a relay metal plate and a metal container, and simultaneously brazing these, the cathode support rod, and the external connection lead.