JPS60145972A - Ceramic-metal bonded body - 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 [Technical Field of the Invention] The present invention relates to a novel ceramic-metal bonded body with high bonding strength.

[Technical background of the invention and its problems] Conventionally, the method of joining a metal member to a ceramic member such as alumina is generally to perform metallization treatment by baking molybdenum paste on the surface of the ceramic member, and then perform nickel plating. C. A method of joining metal members by brazing is used.

In this method, generally the metal member U, AJ220
Kovar or the like having a coefficient of thermal expansion approximately equal to 3 is used.

However, when a metal member with a large coefficient of thermal expansion, such as steel used for structural materials, is used, cracks may occur on the ceramic side due to stress caused by the difference in thermal expansion between the two, or the strength may be lower than the bonding strength. Under load, a phenomenon occurs in which the ceramic is peeled off to the metal side.

In the case of non-oxide ceramics such as 3i 3N and SiC, which have recently attracted attention as high-temperature structural materials and wear-resistant and corrosion-resistant materials, the coefficient of thermal expansion is considerably smaller than that of AJ2203. C-', Si
3 N4: 2.5~4 X 10-'℃-1, Si
C; 4 to 5 x 10-6°C to 1), when these C lamics are joined to steel materials, etc., the above-mentioned phenomenon becomes even more severe, and it is extremely difficult to achieve a practical joining. [Object of the Invention] The present invention has been made in order to solve the above-mentioned problems of the conventional art.
The present invention aims to provide a ceramic-metal bonded body that does not crack or break even due to sudden heat shock that occurs during bonding, by interposing the ceramic-metal bonded body with a metal material.

[Summary of the Invention] In other words, the ceramic-metal bonded body of the present invention includes a metal material having a coefficient of thermal expansion similar to that of the Hiramix member between the ceramic member and the metal member on the side in contact with the ceramic member. and a ductile metal material is placed on the side in contact with the metal member, and the ceramic member and the metal member are bonded in this state.

Ceramic members to which the present invention is applied include oxide-based ceramic members such as alumina and magnesia, as well as non-oxide-based ceramic members such as silicon nitride, silicon carbide, and Xialon. Applicable to dense materials fired by hot press etc.

In the present invention, the metal material disposed on the side in contact with the ceramic member has a coefficient of thermal expansion that differs from the ceramic member by 4.
．． 0x10-6°C-1 or less is suitable, such as molybdenum (3,7~5°3x10-"°C-')
, tungsten (approximately 4.5×10 −6° C. −1), and the like.

In the present invention, the value of the thermal expansion coefficient is an average value from the cloth temperature to the hard brazing temperature.

Further, these metal materials are used in plate shapes and other shapes.

Further, as the metal material C with high ductility that can be used in the present invention, any metal may be used as long as it has greater ductility than the other two metals, but copper and That alloy is suitable.

Further, ductility is indicated by elongation and reduction of area, and in addition to those with excellent elongation, those with excellent reduction of area are particularly preferable.

This highly ductile metal material is used in plate shapes and other shapes, but the thickness is 0.1 to 0.5 mm, especially 0.2 to 0.4 mm.
Dragon range is suitable. This range is thought to be determined by comprehensive conditions such as the stress relaxation effect due to plastic deformation of the ductile metal and the tensile stress effect generated on the ceramic side due to the difference in the coefficient of thermal expansion. It has been confirmed that excellent effects can be obtained within the above thickness range.

The ceramic-metal bonded body of the present invention is produced by metallizing the surfaces of the ceramic members to be joined using a conventional method and applying nickel electroplating. Nickel electroplating is applied to both sides of metal materials and ductile metal materials whose properties are similar to those of ceramics, and these are heat-treated at around 700℃ in a weakly reducing atmosphere to produce silver solder, copper solder, nickel solder, etc. It is obtained by stacking them on top of each other through hard solder and brazing them together at a temperature above the melting point of the hard solder.

Note that an active metal method and other bonding methods can also be applied.

In this way, even if a sudden heat shock is applied to the ceramic-metal bonded body, the shear stress, etc. is alleviated by the highly ductile metal material, and the ductile metal material is not directly attached to the ceramic member, but is Since it is joined via a metal material with a coefficient of thermal expansion similar to that of the ceramic member, no excessive stress is applied to the ceramic member, and there is no possibility of cracking or destruction near the joining interface of the ceramic member.

[Embodiments of the invention] Next, examples of the present invention will be described.

Example: An aqueous solution consisting of 0.3 Q of lithium molybdate, 0.35 (l) of titanium dioxide, and 1°8 cc of water was applied to the surface of a plurality of ceramic sintered bodies made of silicon nitride sintered under normal pressure, and then air-dried. After heating to 750℃ in air,
The lithium molybdate was melted by heating for 5 minutes, and then fired by heating at 1350° C. for 60 minutes in a nitrogen:hydrogen-1:1 homing gas to form a conductive film.

The conductive film thus formed on the C ceramic sintered body is subjected to nickel deplating, and further heated to 700°C.
Heat treatment was performed for 15 minutes in a weakly reducing atmosphere.

Next, nickel electroplating was applied to both sides of the O13-thick copper plate and the 0.2-thick molybdenum plate, and after heat treatment for 15 minutes in a weakly reducing atmosphere at 700°C, the above-mentioned ceramics were plated as shown in the drawing. A molybdenum plate 4 is placed on the nickel plating layer 2 of the sintered body 1 via a silver solder 3, a C copper plate 5 is placed on the silver solder 3, and then a nickel plate is placed on top of the nickel plated layer 2 via a silver solder 3. A heat-treated pure iron chip 6 was placed thereon and heated at 820° C. for 10 minutes to perform soldering, and then allowed to cool at a cooling rate of about 10° C./min.

In addition, the same process was applied to cases in which a copper plate was not used as a buffer material (Comparative Example 1), a case in which a molybdenum plate was not used (Comparative Example 2), and a case in which neither a copper plate nor a molybdenum plate was used (Comparative Example 3). The shear strength of the ceramic-metal bonded body thus bonded is as shown in the following table.

[Effects of the Invention] As explained above, according to the present invention, m1li! It is possible to alleviate the stress that inevitably occurs when joining ceramic members and metal members with different tensile coefficients at high temperatures, and it is possible to provide a more stable and reliable U-lamitsu'kusu metal bonded body. .

[Brief explanation of drawings]

The drawing is a sectional view showing the structure of a ceramic-metal bonded body according to an embodiment of the present invention. 1... Ceramic sintered body 2...
・・・・・・・・・Nickel plating layer 3・・・・・・
...Silver solder 4 ...Molybdenum plate 5 ...
・・・・・・Copper plate 6・・・・・・・・・・・・Patent attorney representing worn iron chips
Suyama Sa -

Claims (7)

[Claims] (1) A metal material having a coefficient of thermal expansion similar to that of the ceramic member is placed between the ceramic member and the metal member on the side in contact with the ceramic member, and a ductile metal material is placed on the side in contact with the metal member. A ceramic-metal bonded body characterized in that the ceramic member and the metal member are arranged and bonded in this state. (2) The ceramic-metal bonded body according to claim 1, wherein the ceramic member is a non-oxide ceramic member. (3) The ceramic-metal bonded body according to claim 1 or 2, wherein the metal member is a steel material. (4) The metal member placed on the side in contact with the ceramic member has a thermal expansion coefficient difference of 4.0X with the ceramic member.
10=C-1 or less, the ceramic-metal bonded body according to any one of claims 1 to 3. (5) The difference in thermal expansion coefficient with ceramic members is 4°0X
The metal material having a temperature of 10-6°C-1 or less is mainly composed of molybdenum or tungsten.
The ceramic-metal bonded body according to any one of items 1 to 4. (6) The ceramic-metal bonded body according to any one of claims 1 to 5, wherein the ductile metal material is made of copper or a copper alloy. (7) Hiramix according to any one of claims 1 to 6, wherein the joining is performed by hard soldering.
Metal joint.