JP2008137850A - Ceramics metallized component and production method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramics metallized product in which metal and ceramics are easily adhered to each other without undergoing a plating step, and which therefore provides improved productivity, and to provide a ceramics metallized product for use in a magnetron and having excellent reliability/durability. <P>SOLUTION: A method for producing the ceramic metallized component is disclosed which is used for producing the ceramic metallized component made into an integrated component having air-tightness using a metal component and brazing and includes the steps of coating the surface of the metallized layer with paste-like nickel powder, and drying and baking the paste-like nickel powder to form a nickel layer. A ceramics metallized component and a magnetron each produced by the production method are disclosed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a ceramic sealing part.

  Magnetron has evolved greatly for the purpose of developing microwave radar in the Second World War, but in modern times, mass-use products for microwave ovens, which were not initially anticipated, will be produced. became. This is based on the fact that microwaves are applied to water-containing substances, and molecules vibrate according to their period and frictional heat is generated.

  In general magnetrons, ceramic parts such as alumina with good insulating properties are used like power tubes and electron tubes, and such ceramic parts are made of molybdenum-manganese as ceramics in order to ensure airtightness with metal parts. On the other hand, a nickel layer for improving the bonding strength and sealing property is formed on the metallized layer mainly composed of, for example.

  As the method for forming the nickel layer, an electroless plating method in which a metallized ceramic component body is immersed in a plating solution and a nickel plating layer having a predetermined thickness is formed on the surface of the metallized layer. A method of electrolytic plating on the metallized surface through a metal jig or the like is employed.

  However, the nickel layer forming method by the plating method has the following problems.

  According to the electroless plating method, the plating solution used is five times more expensive than the electrolytic plating solution, and the processing steps are complicated.

  On the other hand, according to the electrolytic plating method, a barrel type electrolytic plating method is generally adopted. However, in this method, a large number of small metal parts as a current-carrying medium (media) in a rotating container provided with electrodes. In addition, it accommodates thousands of metallized ceramic parts and energizes the electrodes while rotating the rotating vessel immersed in the electrolytic plating solution, so that the metallized surface that is easily attached to the ceramic parts, such as the peripheral frame If there is a metallized surface that is difficult to be plated, such as the perimeter island, a pin electrode must be inserted as an auxiliary jig into the hole of the ceramic component body in order to form a uniform plating layer. It requires a lot of effort and time.

  Furthermore, since the barrel type electrolytic plating method is rotated, a defect such as cracking or chipping may occur in the ceramic parts due to a collision between the ceramic parts or the rotating container body, which causes a significant decrease in yield. Yes.

  Furthermore, for ceramic parts that use auxiliary jigs such as the pin electrodes, it is naturally necessary to remove the pins after plating.

Therefore, various techniques have been proposed to solve such problems. For example, for the purpose of providing a method for joining magnetron parts with good productivity and yield,
In a joining method for joining a ceramic part and a metal part constituting a magnetron, a step of metallizing the joining surface, a step of plating two or more metals alternately and multiple times on the metallized surface, and heating A technique composed of a process has been proposed (see Patent Document 1). However, since this technique has a plating step, the above problem has not been solved by the nickel layer forming method.

In addition, a paste of metallized component powder is applied to the ceramic surface, the copper alloy thin plate is covered thereon, and the copper alloy thin plate is bonded through a metallized layer by heat treatment to form an easily workable copper alloy layer on the ceramic surface. Or by applying a paste of a metallized component powder to the ceramic surface, applying a paste made of a copper alloy powder on the ceramic surface, and then applying a heat-treatable copper alloy powder paste to the easily processable copper alloy layer by heat treatment There is a method of forming on the ceramic surface through a metallized layer (see Patent Document 2). However, this technique is a method for forming a metallized layer, and has a different purpose and effect from the present invention.
JP-A-8-115661 JP-A-8-91970

  In view of the above problems, the present invention relates to ceramic metallized parts, easily bonding metal and ceramics without going through a plating process, improving productivity, and having excellent reliability and durability. It is intended to provide products.

  In order to achieve the above-mentioned object, the present invention is a ceramic metallized part which is made into an airtight integral part by brazing a metal part, and paste-like nickel powder is applied on the metallized layer, dried and baked. It is a manufacturing method of the ceramic metallized component of the process of forming a nickel layer.

Moreover, this invention can also be made into the ceramic metallized component manufactured by the manufacturing method of the said ceramic metallized component.

  Furthermore, in the ceramic metallized component, a ceramic metallized component particularly used for a magnetron can be used.

  According to the ceramic metallized component and the manufacturing method thereof according to the present invention, by forming a nickel layer using nickel paste instead of nickel plating, by brazing with a metal component equal to or more than the nickel layer by plating method There is an excellent effect that significant cost reduction can be achieved while ensuring adhesive strength, airtightness and sealing properties.

  In addition, according to the ceramic metallized parts and the manufacturing method thereof according to the present invention, unlike conventional plating methods, there is an effect that the load on the environment is much less because large equipment such as chemicals, a large amount of washing water, and electric power are not used. can get.

  Furthermore, according to the ceramic metallized component and the manufacturing method thereof according to the present invention, since the ceramic metallized component is not rotated as in the barrel-type electrolytic plating method, there is a defect such as cracking or chipping in the ceramic component due to a collision between the ceramic components or the rotating container body. Since it does not occur and the number of defects is drastically reduced, it is possible to suppress the generation of industrial waste such as ceramic waste.

  Furthermore, according to the ceramic metallized part and the manufacturing method thereof according to the present invention, the work efficiency is improved in that the pinning work after the plating process is not required, compared to the ceramic part using an auxiliary jig such as a pin electrode. improves.

  In order to solve the above-mentioned problems, the present inventors pay attention to nickel paste as a method for forming nickel layer 9 instead of plating, and by controlling the particle size, coating thickness, baking conditions, and the like of this paste, The knowledge that it is possible to manufacture ceramic metallized parts 2 formed with a nickel layer 9 that can secure the adhesive strength, hermeticity, and sealability by brazing with metal parts, which is equal to or better than the nickel layer 9 by plating. Obtained. That is, the present invention is characterized in that the nickel layer 9 is formed by applying paste-like nickel powder to the surface of the metallized layer 8 formed on the surface of the ceramic component body 5, drying and baking. And Hereinafter, a ceramic metallized component 2 according to the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory view showing a manufacturing process of a ceramic metallized component 2 according to the present invention. FIG. 1A shows a manufacturing process of the ceramic metallized component 2 according to the present invention, and FIG. 1B shows a method for forming the nickel layer 9 by nickel plating for comparison with the prior art. Note that processes marked with an asterisk (*) in the figure may be unnecessary depending on the product type.

  First, a molybdenum paste is applied to the ceramic component body 5 and dried, and the metallized layer 8 is fired. Thereafter, nickel paste is applied to the surface of the metallized layer 8 and dried. After sintering (fixing firing), a completion inspection is performed. Here, when compared with the prior art (see FIG. 1B), it is clear that the nickel plating step can be omitted.

  Moreover, it is preferable that the particle size of the powder used for a nickel paste is 0.4-1.0 micrometer.

  Furthermore, the coating thickness after baking is preferably 3 to 10 μm.

  Furthermore, the baking treatment is preferably performed at a temperature of 800 ° C. or higher and a reducing gas such as hydrogen or a vacuum as the atmosphere.

  Next, the structure of the ceramic metallized component 2 for magnetron according to the present invention will be described with reference to the drawings.

  FIG. 2 is an explanatory view showing the structure of an embodiment of the ceramic metallized component 2 according to the present invention, which is a magnetron component (part). This magnetron component 1 is obtained by brazing an outer case 3 and electrode leads 4 which are metal components to a ceramic metallized component 2 for magnetron.

  FIG. 3 is an explanatory view showing the detailed structure of the ceramic metallized component 2 for magnetron formed up to the nickel layer 9 before brazing. This component includes a peripheral frame portion 6 and a peripheral inner island portion 7 formed on an end surface of a ceramic component element body 5 made of a cylindrical alumina sintered body, and the surfaces of the peripheral frame portion 6 and the peripheral inner island portion 7. The peripheral frame metallization layer 8a and the peripheral inner island metallization layer 8b are formed respectively by the molybdenum-manganese method. The peripheral frame metallization layer 8a and the peripheral inner island metallization layer 8b are electrically connected by the groove 10. Is insulated. Accordingly, the metallized layer 8 is formed with a peripheral frame part nickel layer 9a and a peripheral inner island part nickel layer 9b, respectively.

  The nickel layer 9 of the ceramic metallized component 2 for magnetron 2 is obtained by applying a paste of nickel powder having a particle size of 0.7 μm to a peripheral frame metallized layer 8a and a peripheral inner island metallized layer 8b by screen printing. Then, after drying with a dryer, it is formed by baking through a continuous sintering furnace set at 875 ° C. in a hydrogen gas atmosphere. The nickel layer 9 has a thickness of about 5 μm.

  FIG. 4 is an explanatory view of a method for manufacturing the magnetron ceramic metallized component 2 using a conventional auxiliary jig such as a pin electrode. As a comparative example to clarify the contribution to the prior art, a sample of the conventional method was created and compared. That is, the metallized layer 8 is formed on the ceramic component body 5 by the same manufacturing method as in the above embodiment, and then, as shown in the figure, the peripheral inner island portion 7 of the ceramic component body 5 on which the metalized layer 8 is formed. A pin electrode 11 made of stainless steel was inserted into the hole, and a nickel plating layer 9 of about 2 μm was formed on the upper end surfaces of the peripheral frame metallization layer 8a and the peripheral inner island metallization layer 8b by a barrel-type electrolytic plating method. The number of ceramic component bodies 5 in which the metallized layer 8 charged into the barrel is formed and the pin electrode 11 is inserted is 3500, and the time required for inserting the pin electrode 11 is about 1.3 hours. It is.

  As a result of comparing the brazing strength between the nickel layer 9 and the metal part for the ceramic metallized parts 2 for magnetrons of the examples and comparative examples thus prepared, the brazing strength according to the examples is equal to or greater than the brazing strength of the comparative example. The strength of was shown.

  In the sample prepared in the comparative example, in the inspection after plating, about 7% of defects such as defective nickel layer formation, cracking, chipping, and dirt were generated. On the other hand, only about 2% of defects occurred in the examples.

  Furthermore, the production time according to the example was about 1/7 compared with that of the comparative example.

  In the comparative example, about 90% of nickel in the plating solution is attached to a small metal part as a current-carrying medium, resulting in a large material loss.

  As described above, the present invention can improve the productivity by facilitating the adhesion between metal and ceramics in the manufacture of magnetrons, and can provide ceramic magnetron products with excellent reliability and durability to consumers. Therefore, industrial applicability mainly in the microwave oven manufacturing process is extremely high. In addition, ceramic sealing products other than magnetrons can be used to manufacture highly reliable ceramic metallized parts.

Explanatory drawing which shows the manufacturing process of the ceramic metallized components concerning this invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the structure of one Example magnetron components (part) of the ceramic metallized components concerning this invention. Explanatory drawing which shows the detailed structure of the ceramic metallization components for magnetrons formed to the nickel layer before brazing. Explanatory drawing of the manufacturing method of the ceramic metallized components for magnetrons which use auxiliary jigs, such as the conventional pin electrode.

Explanation of symbols

1 Magnetron parts (part)
2 Ceramic metallized parts for magnetron 3 Outer case 4 Electrode lead 5 Ceramic component body 6 Peripheral frame part 7 Peripheral island part 8 Metallized layer 8a Peripheral frame part metallized layer 8b Peripheral inner part metallized layer 9 Nickel layer 9a Peripheral frame part Nickel layer 9b Nickel layer 10 on the inner periphery 10 Groove 11 Pin electrode

Claims (3)

  Ceramics metallized parts that are made into an airtight integrated part by brazing metal parts. Ceramics characterized in that a nickel layer is formed by applying paste-like nickel powder on this metallized layer, drying and baking treatment Manufacturing method of metallized parts. A ceramic metallized part manufactured by the method for manufacturing a ceramic metallized part.   Ceramic metallized parts used for magnetrons in the ceramic metallized parts.

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