JPH075416B2 - Ceramicizing method of metallizing - Google Patents

Description

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

(Prior Art) Ceramic materials have recently begun to be used in a wide range of fields such as structural materials and functional materials due to their excellent characteristics. In many cases, the ceramic is used alone to form the component, but in order to use the ceramic in more fields, it is necessary to be able to bond with a metal. For this reason,
It is desired to establish a metallizing method for ceramics.

By the way, conventionally, the following method is known as a metallizing method for ceramics.

． A method in which powder containing Mo or W as a main component is applied to the surface of a ceramic base material, heated to 1400 to 1700 ° C. in a reducing atmosphere to react with the ceramic base material, and metallized.

． A method of arranging a foil of Au or Pt on the surface of a ceramic base material, heating the foil while applying pressure, and performing metallization.

However, the above method is mainly used for ceramics.
It is intended for Al ₂ O ₃ and cannot be metallized with high adhesion to nitride ceramics such as aluminum nitride, which has been recently receiving attention. Further, in the above method, since an expensive precious metal is used, the economical efficiency is low and a high pressure is required for the purpose of enhancing the adhesiveness, which is not preferable for metallizing to an electronic component or the like which is not susceptible to deformation.

Therefore, active metals such as Ti and Zr are Cu, Ni,
In an alloy with a transition metal such as Fe, the melting point (Ti; 1720 ° C, Zr; 1860 ° C) of the simple substance of the active metal in the eutectic composition region
Melting point of Cu, Ni and Fe (1083 ℃, 1453 ℃, 1534 ℃ respectively)
Focusing on lowering the melting point by several hundred degrees Celsius as compared with the above, after laminating the active metal layer and the transition metal layer, specifically the alloy foil on the ceramic base material, heat treatment at a high temperature with a good melting point of those alloys. And metallizing (JP-A-56-16)
3093 gazette) is known. According to this method, since the surface of the ceramic base material is sufficiently wetted by the synergistic liquid of the transition metal and the active metal, almost no pressurization is required, and due to the high cost of the active metal, strong adhesion to the ceramic base material is obtained. Can be metallized with. However, such a method has a problem that a special alloy foil such as an alloy layer of an active metal and a transition metal is required. This also applies to the method of using alloy powder instead of alloy foil, and there is a problem that a special alloy is required in each case.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-mentioned conventional problems, and is capable of performing metallizing with high adhesion to ceramics by a simple process without using a special alloy. The aim is to provide a metallizing method that can be carried out.

[Structure of the Invention] (Means for Solving Problems) The present invention relates to a Ti powder on a metallized surface of ceramics,
This is a metallizing method for ceramics, which comprises applying Zr powder or a mixed powder thereof to a concentration of 0.1 to 10 mg / cm ² and then disposing a metal brazing material on the applied surface and heating.

As the above ceramics, nitride ceramics such as AlN, Si ₃ N ₄ and BN, carbide ceramics such as SiC, A
Various ceramics including oxide ceramics such as l ₂ O ₃ can be mentioned.

As a method of applying the Ti powder, Zr powder or a mixed powder thereof, a method of applying an organic binder dissolved in a solvent on the metallizing surface of the ceramic in advance and then performing the method, the Ti powder, the Zr powder or these. Mixed powder, an organic binder and a solvent are kneaded to form a mixed composition, and the mixed composition is Ti powder, Zr powder, or a mixed powder of these is 0.1
A method may be mentioned in which the metallized surface of the ceramic is coated with a mesh plate or the like so that the coating amount is about 10 mg / cm ² . The organic binder and solvent used here are not particularly limited, but those which are completely decomposed and removed by heat treatment after coating are desirable. As a specific organic binder,
Synthetic rubber, polyvinyl alcohol, ethyl cellulose and the like can be mentioned, and as the solvent, ethanol, tetralin and the like can be mentioned.

The coating amount of the above Ti powder, Zr powder or mixed powder thereof is 0.
The reason for limiting 1 to 10 mg / cm ² is that when the range deviates from these ranges, the metal brazing filler metal is widely spread in the heat treatment after the metal brazing filler metal is placed on the coated surface of the metal powder, and good metallization is achieved. Because you can't. For example, Ag brazing material coated surface of the Al ₂ O ₃ disc of diameter 10mm coated with Ti powder (72
% Ag-Cu) 0.1g, and then heat in vacuum at 830 ℃ for 10 minutes. From the characteristic diagram of the spread state of Ag brazing material,
Ag coating amount of less than 0.1 mg / cm ^{2 or more} than 10 mg / cm ²
It can be seen that the spread of the brazing material is low and good metallizing cannot be performed. These results were the same in the case of Zr and the mixed powder of Ti and Zr. However, the mixing ratio of Ti and Zr is not particularly limited and may be arbitrary.

The particle diameters of the Ti powder, Zr powder, and mixed powder thereof are not particularly limited, but the larger the particle diameter, the lower the fluidity, so the particle diameter is preferably 10 μm or less.

As the metal brazing material, for example, Ag-Cu brazing material, Ag-Cu
-Sn brazing material, Ag-Cu-Zn brazing material, etc. can be mentioned. It is desirable that the amount of metal brazing material to be applied to the surface to which Ti powder or the like is applied be minimum. This is because, in general, the coefficient of thermal expansion differs greatly between metal and ceramics, and cracks may occur in the ceramics due to the thermal stress generated due to the difference in the coefficient of thermal expansion. This thermal stress is more likely to occur as the metallizing layer is thicker. Therefore, it is desirable that the metal brazing material layer is thin, that is, the amount of metal brazing material is small.

In the heat treatment step, the atmosphere is preferably a non-oxidizing atmosphere such as vacuum or argon.

(Operation) The present invention, therefore, is applied to the metallizing surface of ceramics.
0.1 to 10 mg / cm ^{2 of} Ti powder, Zr powder or mixed powder of these
After coating so that the metal brazing material is placed on the coated surface and heated, the ceramics can be easily metallized. Especially, Al, which is widely used for various airtight tubes, etc.
It is suitable as a metallizing method for easily and inexpensively joining ₂ O ₃ and a sealing metal.

(Examples of the Invention) Examples of the present invention will be described in detail below.

Example 1 First, a spray-equipped container in which a synthetic rubber paste was stored on the metallizing surface of an Al ₂ O ₃ disc having a diameter of 30 mm was sprayed for 2 seconds from a position 20 cm away from the metallizing surface, and the thickness was 1 m.
A synthetic rubber glue film around m was formed. Subsequently, Ti powder having a diameter of 10 μm or less was applied on the coating in an amount of 0.5 mg / cm ² . Next, 0.1g of Ag brazing rod (72
% Ag-Cu) and then placed in a 2 × 10 ⁻⁵ torr vacuum furnace and heated at 830 ° C. for 10 minutes.

Then, when the Al ₂ O ₃ disk was taken out in the furnace after cooling, Ag brazing was completely spread over the entire metallized surface of the Al ₂ O ₃ disk, and the disk was well metalized. Was confirmed.

Example 2 First, an Al ₂ O ₃ cylinder having an outer diameter of 60 mm, an inner diameter of 50 mm and a height of 60 mm was prepared. In addition, directly connect Zr powder and Ti powder of 5 μm or less
The mixture was mixed at a ratio of 1: 9, and the mixed powder was kneaded with a polyvinyl alcohol solution dissolved in ethyl alcohol to prepare a mixed composition.

Then, on the metallized surface of the end of the Al ₂ O ₃ cylinder,
A 00 mesh stainless mesh plate was placed, the mixed composition was cast on the mesh plate, and then pressed by a rubber roller to apply the mixed composition evenly. At this time, the amounts of Ti powder and Zr powder in the applied composition were adjusted to be 1 mg / cm ² . Next, Ag wax (BA
g-7; 22Cu-17Zn-5Sn-Ag) wire 0.3g,
These were placed in a 2 × 10 ^-5 torr vacuum furnace and heated at 750 ° C for 10
Heated for minutes.

Then, when the Al ₂ O ₃ cylindrical body was taken out from the furnace after cooling, it was confirmed that the coated surface of the cylindrical body was completely covered with Ag solder and was extremely well metallized.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to perform metallization with high adhesion to ceramics by a simple process without using a special alloy, and thus to improve Al ₂ O ₃
It is possible to provide a ceramic metallizing method that can be suitably used for joining the airtight tube and the sealing metal.

[Brief description of drawings]

The drawing is a characteristic diagram showing the relationship between the coating amount of Ti powder and the spread rate of the Ag brazing material arranged on the Ti coating surface by heat treatment.

Claims (4)

[Claims] 1. A Ti powder, a Zr powder, or a mixed powder of these powders is applied to a metallized surface of a ceramic so as to have a concentration of 0.1 to 10 mg / cm ^2, and a metal brazing material is placed on the applied surface and heated. A method of metallizing ceramics, characterized by: 2. Prior to applying Ti powder, Zr powder or a mixed powder thereof to the metallized surface of ceramics,
The method for metallizing ceramics according to claim 1, wherein an organic binder dissolved in a solvent is applied to the metallizing surface. 3. A Ti powder, a Zr powder or a mixed composition of these, a Ti powder, a Zr powder or a mixed powder of 0.1 to 10 mg / mixed powder on the metallized surface of ceramics. A method of metallizing ceramics according to claim 1, characterized in that the coating is carried out so as to be cm ² . 4. The composition according to claim 3, wherein the mixed composition is applied to the metallizing surface of the ceramics through a mesh plate which is in contact with the metallizing surface.
A method for metallizing ceramics according to the item.