JPS58145669A - Method of bonding ceramics to copper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for joining ceramics and copper, and particularly to a method for joining ceramics and copper easily without using a brazing material.

Conventionally, when bonding ceramics such as alumina ceramics and copper, a metallizing ink containing molybdenum, tungsten, etc. as the main ingredients is applied to the bonding surface of the fired ceramics, then re-fired to form the entire metallized layer, and then metallized. In order to increase the wettability of the brazing metal, the layers are surface-treated with nickel plating, etc., and then ceramics and copper that have been subjected to human blood treatments such as sintering are bonded together by heating. There is.

Therefore, the process becomes diverse and long, and
The bonding strength varies greatly depending on the thickness of the applied metallizing ink, the firing ambient atmosphere, temperature and time, and there are problems such as high cost since a brazing metal is required.

The present invention has been made in view of the above-mentioned problems, and its object is to insert ceramics, copper, and total chromium oxide or copper containing an amount of chromium between them, and then To provide a method for joining ceramics and copper, which eliminates the need for a brazing metal by heating in atmosphere, temperature, and time, and which can increase the joining strength in a simple process. below,
A special embodiment of the present invention will be described in detail with reference to the drawings.

In the first embodiment of the joining method according to the present invention, first, chromium is vapor-deposited or chromium is deposited to a thickness of 1100 A' or more on the joining surface of a ceramic such as alumina, mullite, zircon, steatite, etc. to be joined with copper. Plating to a total film thickness of 0.1μ or more, then 10'-' To
Oxidation treatment is performed by heating at 100° C. or higher for 10 minutes or longer in an air atmosphere of rr or higher to form a film of chromium oxide, such as chromium oxide (CrlOB). Next, a steel mold of a predetermined shape is fitted onto the chromium oxide coating of the ceramic in a vacuum atmosphere (for example, a vacuum furnace) of 10'-' Torr or less or in a copper oxide film. Both are placed in a non-oxidizing gas atmosphere such as helium or hydrogen, and finally heated at a heating temperature of 900°C or higher for 10 minutes or more to completely bond the ceramic and steel materials, and both are placed in an airtight environment. Good bonding between ceramics and copper can be achieved by slow cooling (vacuum furnace cooling) or slow cooling in a gas atmosphere that does not oxidize copper to reduce residual stress in the steel material through its plastic deformation.

By the method of the first embodiment described above, that is, a chromium film of about 1 μm is vacuum-deposited on the joint surface of alumina ceramics, and the chromium film is vacuum-deposited with a thickness of about 5 μm in air at 10’-1 to 10’ Torr.
After heating for 10 minutes at a temperature of 00°C, a copper phase for bonding is placed and heated at 10'-' to 1O- to prevent the steel material from oxidizing.
The joint between alumina ceramics and copper was heated continuously for 25 minutes at a temperature of 1000°C in a vacuum atmosphere of II Torr, and then gradually cooled in a vacuum atmosphere.
Figures 1, 2, and 3.

The result was an enlarged view (grain boundary diagram) shown in FIGS. 4 and 5. In other words, Figure 1 is a secondary electron image taken with an X-ray microanalyzer. The black part on the right is alumina ceramics, the slightly white part on the left is copper, and the wave-shaped part between the two is chromium oxide. It is. Further, Fig. 2 is a characteristic X-ray image taken by an X-ray microanalyzer showing the entire dispersion state of chromium, and the white part in the center is chromium. moreover,
FIG. 3 is a characteristic X-ray image taken by an X-ray microanalyzer showing the dispersion state of oxygen, and the white parts dotted on the right are oxygen. Additionally, Figures 4 and 5 are characteristic X-ray images taken by an X-ray microanalyzer that similarly show the dispersion state of aluminum and copper.The white part on the right in Figure 4 is aluminum, and the white part on the left in Figure 6 is Part of the white part is copper.

Here, the bonding strength between the ceramic and copper bonded by the method of the first example was 55 kg/m- or more.

In addition, the chromium film formed on the bonding of ceramics is formed by vapor deposition at a minimum of 100A', and the bonding with copper is also uniform, resulting in diffusion of chromium (both into the ceramics and steel). However, in the case of plating, it has been confirmed through experiments that a uniform diffusion layer cannot be obtained unless the film thickness is at least α1μ.

Furthermore, when forming a chromium film by applying 1,100 mesh of chromium metal powder in paste form with an appropriate solvent, experiments have similarly shown that the film must be applied to a thickness of 0.1μ or more. It was confirmed.

Furthermore, the oxidation treatment conditions for the chromium film depend on the film thickness, but the above-mentioned minimum film thickness (approximately 0.01μ) and the above-mentioned conditions (1
0 s Torr, 100' C11 o min) was required as a minimum. This is thought to be because chromium has a high affinity for oxygen, so it easily becomes chromium oxide with a trace amount of oxygen in the air.

Next, in a second embodiment of the bonding method according to the present invention, first, a chromium oxide such as chromium oxide (crtos) is applied to the bonding surface of a ceramic such as alumina or mullite to be bonded to copper.
Chromium oxide (Cr203) vapor-deposited to a thickness of k100A' or more or made into a paste with an appropriate solvent
Chromium oxide powder of about 1100 mesh? 0
．． Apply with a film thickness of 1μ or more to form a complete chromium oxide film. Next, a steel material of a predetermined shape is superimposed on the chromium oxide coating of the ceramic to form a 10'-' TOr.
Both were placed in a vacuum atmosphere of less than r or in a gas atmosphere that does not oxidize copper, and finally heated for more than 10 minutes at a heating temperature of 900'C or more in the same way as in the first embodiment and placed in a ceramic atmosphere. By slowly cooling the steel material and reducing the residual stress of the steel material through its plastic deformation, a good bond between the ceramic and the copper is achieved.

Thirdly, in the eighth embodiment of the joining method according to the present invention, first, there is a thickness of about 0.0 mm between the joining surfaces of the ceramic and the steel material having a predetermined shape.
A copper foil containing about 0.1 to 0.6% by weight of chromium and about 0.1 to 0.6% by weight is entirely inserted. Next, the ceramics and steel materials with copper foil completely interposed were placed in a vacuum atmosphere of less than k 10-4 Torrl! Deliver in a gas atmosphere that does not cause oxidation, and finally heat for 10 minutes or more at a heating temperature of 900°C or higher to fully bond the ceramic and copper materials, and place the bonded materials in a vacuum atmosphere or in a gas atmosphere that does not cause tone oxidation. In the process, a good bond between the ceramic and the copper is achieved by gradually cooling the steel material to reduce all the residual stress in the steel material through its plastic deformation.

As described above, the present invention is a method for joining ceramics and copper, in which ceramics, copper, and all chromium oxides are heated and joined together, so unlike conventional methods, expensive molybdenum, tungsten, etc. are used. This eliminates the need for forming a metallized layer by re-firing and the use of a brazing filler metal, making it possible to reduce the manufacturing cost, and also to shorten the process and facilitate manufacturing.

In addition, since this is a method of joining ceramics and copper by heating through copper containing 0.1 to 0.6 chromium, in addition to the above-mentioned effects, Effects such as further shortening of the process and facilitation of manufacturing can be achieved.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, FIG. 4, and FIG. 5 are enlarged views (grain boundary diagrams) of the bonded portion of ceramic and copper bonded by the bonding method according to the present invention, respectively. Fig. 1 44- Fig. 3 Fig. 2 Fig. 4/-/ Fig. 41 1- No. 51

Claims (1)

[Claims] (1) A method for joining ceramics and copper, which is characterized in that ceramics, copper, and all chromium oxides are bonded together by heating. (2) Chromium'zloOA is applied to the joining surface of the ceramics.
2. A method for joining ceramics and copper according to claim 1, characterized in that chromium oxide gold is obtained by vapor depositing chromium oxide gold and then subjecting it to oxidation treatment. (3) A method for joining ceramics and copper according to claim 1, characterized in that the joining surface of the ceramic is plated with chromium of α1μ or more, and then oxidized to obtain chromium oxide gold. 3(4) A method for joining ceramics and copper according to claim 1, characterized in that chromium oxide of 10OA' or more is deposited on the joining surface of the ceramic to obtain all the chromium oxide. (5) A method for joining ceramics and copper according to claim 1, characterized in that 1μ or more of chromium oxide powder C) is applied to the joining surface of the ceramic to obtain all the chromium oxide. . (6) Heating is continued for 10 minutes or more at a temperature of 900° C. or higher in a vacuum atmosphere of 10-4 Torr or lower, and then slowly cooled. A method for joining ceramics and copper according to any one of the preceding paragraphs. (7) Claims 1 to 5 are characterized in that the heating is continued for 10 minutes or more at a temperature of 900°C or higher in a gas atmosphere that does not cause tone oxidation, and then slowly cooled. The method for joining ceramics and copper according to any one of the above. (8) A method for joining ceramics and copper, characterized in that the ceramics and copper are joined by heating via copper containing chromium in an amount of about α1 to α6% by weight. (9) The heating is continued at a temperature of 900° C. or higher for 10 minutes or more in a vacuum atmosphere of k, 10-' Torr or lower, and then slowly cooled. How to join ceramics and copper. (7) Claim 8, which is characterized in that the heated metal or wire mesh is kept in a gas atmosphere that does not oxidize at a temperature of 900° C. or higher for 10 minutes or more, and then slowly cooled. A method of joining ceramics and copper.