JP2729751B2 - Joining method of alumina ceramics and aluminum - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining aluminum having a specific composition and alumina ceramics which require strength and reliability of a joint portion as a structural component, and relates to an aluminum alloy containing a specific amount of Si. By intervening or further metallizing and joining Ti and Cu to alumina ceramics, the base metal
The present invention relates to a method for bonding alumina ceramics and aluminum that can provide a bonding strength of not less than MPa.

[0002]

2. Description of the Related Art As a joining method of an alumina ceramic and a metal, a metallizing metal such as Mo-Mn is baked in advance on the surface of the alumina ceramic and joined using a silver brazing material, or an active metal such as Ti. An active metal method in which bonding is performed with an intervening metal is known. As a method of easily joining alumina ceramics and metal by solving the problem of strict atmosphere adjustment for metallization and the problem of the active metal method that needs to be heated to 950 ° C. or more, Al or Al alloy is made of Al—Si. A method of bonding at a heating temperature of 650 ° C. or lower with a three-layer structure material sandwiched between alloys (Japanese Patent Publication No. 2-49267) has been proposed.

[0003] Metallization of the ceramic surface in a vacuum is unfavorable because the vapor pressure of the silver brazing material or the like is increased, which is undesirable. Metallization or further bonding in a reduced-pressure inert gas or nitrogen gas or a mixed gas thereof (particularly). No. 2-88482) has also been proposed.

As a metallizing composition used for brazing alumina ceramics for a semiconductor package and an aluminum lead wire, a composition containing a predetermined amount of zirconium or a hydride thereof and aluminum or a hydride thereof (Japanese Patent Laid-Open Publication No. No. 54181) has been proposed.

[0005]

In the case of bonding alumina ceramics and aluminum, the Mo-Mn metallized layer has poor wettability with the aluminum brazing material and low bonding strength. However, this method is used for brazing lead wires of a semiconductor package, and is not suitable for a case where strength and reliability of a joint portion are required as a heat exchanger or a structural component. Also, aluminum materials used for structural parts, for example, 3
Since the melting point of the 003 alloy material is around 630 ° C., it is not preferable to apply heating exceeding 600 ° C. to the structural component during joining.

According to the present invention, in joining aluminum and alumina ceramics having a specific composition that requires strength and reliability of a joining part as a structural component, the heating temperature at the time of joining is not more than 600 ° C. The purpose of the present invention is to provide a method of joining alumina ceramics and aluminum that can achieve a joining strength of up to.

[0007]

According to the present invention, an alumina ceramic material, Si 0.6 wt% or less, Fe 0.7 w
For bonding with an aluminum material containing t% or less, Cu 0.2 wt% or less, and Mn 2.0 wt% or less, Si 9.0 wt%
% To 11.0 wt%, Fe 0.8 wt% or less, Cu0.
3 wt% or less, Mn0.05 wt% or less, Mg0.05
wt% or less, Zn0.1 wt% or less, Ti0.2 wt%
In the following, 590 ° C. to 60 ° C. in a vacuum or an inert atmosphere with an aluminum alloy material substantially consisting of Al intervening.
This is a method for bonding alumina ceramics and aluminum, wherein the bonding is performed by heating to 0 ° C. to obtain a bonding strength of 200 MPa or more.

[0008] Further, according to the present invention, in the above structure,
The TiH paste is screen-printed in advance on the surface to be joined of the alumina ceramic material, and is printed in a vacuum at 900 ° C.
A joint method of alumina ceramics and aluminum, which is characterized by being metallized at 1000 ° C., is also proposed.

In the present invention, the alumina ceramic material includes any known composition such as a material containing silica as a main material and a sintering aid, and the aluminum material includes a material used for a known structural material. However, as impurities 0.6 wt% or less of Si, 0.7 wt% or less of Fe,
It is desirable that u be 0.2 wt% or less and Mn 2.0 wt% or less.

In the present invention, it is important that the aluminum alloy material for bonding contains 9.0 to 11.0% by weight of Si, and a bonding strength of 200 MPa or more cannot be obtained outside this range. Further, as impurities, Fe 0.8 wt% or less, Cu 0.3 wt% or less, Mn
0.05 wt% or less, Mg 0.05 wt% or less, Zn
It is desirable that the content be 0.1 wt% or less and Ti be 0.2 wt% or less. Further, the bonding temperature is limited to 590 ° C. to 600 ° C., but outside this range, a bonding strength of 250 MPa or more cannot be obtained. The rate of temperature rise up to the above joining temperature is 1
The heating time at about 590 ° C. to 600 ° C. is preferably about 10 minutes to 15 minutes, and the furnace may be cooled thereafter.

In the joining of the alumina ceramic and aluminum according to the present invention, it is effective to metallize titanium on the surface to be joined of the alumina ceramic material, but it is preferable to use titanium foil or titanium powder in terms of joining strength. Instead, a TiH paste was screen-printed on the surface to be joined, and this was printed in a vacuum at 900 ° C to 100 ° C.
By adopting the method of metallizing at 0 ° C., a dense metallized layer is formed on the surface of alumina ceramics, and the above aluminum alloy material is interposed between 590 ° C. and
When heated to 600 ° C., a bonding strength of 200 MPa or more can be obtained. The TiH paste has a particle size of 5 to 5.
Since about 10 μm of TiH powder is used to form a single paste state, the oxidation reaction and high-temperature carburization of an ordinary organic binder are apt to proceed. It is desirable to use it as the main material and dilute the diluent with diethyl ether to adjust the viscosity. Metallized layer thickness is 5μ
m to 20 μm are preferred.

The use of Cu for the metallization layer is extremely effective for joining alumina ceramics and aluminum, and the diffusion of Ti during high-temperature liquefaction of Cu is much larger than that of the case where Ti alone is used. C has a high progression into the world and produces good interface formation.
Use with u is a very effective method.

[0013]

According to the present invention, the formation of an interface between alumina ceramics and aluminum is controlled by adding Si 9.0 wt% to 11.0 wt%.
% By direct bonding at 600 ° C. for about 15 minutes using an aluminum alloy material containing 0.1% or a metallizing treatment of Ti and / or Cu on an alumina surface in advance at a high temperature of 900 ° C. or more, and then bonding the above alloy material Thereby, the strength of the bonding interface almost reaches the base metal strength. Also, as is apparent from the examples, even a bonded body of 20 mm square is satisfactorily bonded without generation of interfacial peeling or cracking. Usually, a large thermal stress is generated in the bonding of alumina and a metal having a large difference in thermal expansion coefficient. Although a sound bonded body cannot be obtained due to interfacial peeling or cracking on the alumina side even when it occurs and is bonded, it is considered that aluminum itself easily plastically deforms in the method of the present invention, and there is almost no adverse effect due to thermal stress. .

[0014]

【Example】

Example 1 Alumina ceramics was a normal pressure sintered body containing 92 wt% Al ₂ O ₃ and about 8 wt% of a sintering aid.
A material having a four-point bending strength of 300 MPa to 350 MPa was used. The shape was a cubic shape of 20 mm × 20 mm × 20 mm, and the joining points were used in a baked state. JIS3003 material is used for the aluminum material to be joined, and the shape is a cubic shape of 20 mm × 20 mm × 20 mm. Aluminum alloy materials for joining include Fe, Cu, Mn, Zn
Impurity concentration is the same, and the Si content is 10.0 wt.
% (Invention 1), 8.0 wt% (Comparative Example 1) and 11.
Three types of 5 wt% (Comparative Example 2) were used. The joining piece was 20 mm × 20 mm × 20 mm. An aluminum alloy piece for bonding is interposed between the alumina ceramic and the aluminum material, and the degree of vacuum is 1 × 10 ⁻⁵ to 10 ⁻⁷ Torr.
Bonding was performed for 15 minutes in an atmosphere of r at 580 ° C. to 610 ° C. with various heating temperatures, and after cooling in a furnace, the bonding strength was measured. Table 1 shows the results.

[0015]

[Table 1]

Example 2 A comparison was made using pure Ti foil having a thickness of 50 μm when titanium was heated to 950 ° C. in an atmosphere having a degree of vacuum of 1 × 10 ⁻⁶ Torr and metallized on the surface to be bonded of the alumina ceramics of Example 1 and metallized. Example 3, Invention 2, coated with TiH paste (amylose binder, diluent: diethyl ether)
Alumina ceramics provided with three types of metallized layers of the present invention 3 prepared by screen printing the same TiH paste to a thickness of 10 μm was prepared. The above alumina ceramic was bonded to the aluminum material to be bonded in Example 1 using Si 1.
Using a 0.0 wt% aluminum alloy piece for bonding according to the present invention, 600 mm in an atmosphere having a degree of vacuum of 1 × 10 ⁻⁵ Torr.
Joining was performed by heating to 15 ° C. and holding for 15 minutes, and after cooling in a furnace, the joining strength was measured. As a result, Comparative Example 3 was 30M
The present invention 2 applied with the paste is 2
00MPa, averaged 2 in screen printed invention 3
At 60 MPa, some fractures occur not in the joint surface but in the alumina matrix, and thus the alumina / aluminum interface strength obtained is the highest.

Example 3 Cu was applied to the surface to be joined of the alumina ceramics of Example 1 in an atmosphere having a degree of vacuum of 1 × 10 ⁻⁷ Torr at 900 to 1100.
Comparative Example 4 using 50 μm thick pure Cu foil, Comparative Example 5 applying a Cu paste (biochemical cellulose binder, diluent: ether), and screening the Cu paste to a thickness of 10 μm when metalizing by heating to 50 ° C. Alumina ceramics having three types of printed metallized layers of the present invention were prepared. The above alumina ceramic was bonded to the aluminum material to be bonded in Example 1 using Si 1.
Using a 0.0 wt% aluminum alloy piece for bonding according to the present invention, 600 mm in an atmosphere having a degree of vacuum of 1 × 10 ⁻⁵ Torr.
Joining was performed by heating to 15 ° C. and holding for 15 minutes, and after cooling in a furnace, the joining strength was measured. As a result, Comparative Example 4 was 100
Comparative Example 5 is 150 MPa, while the average of the present invention is 250 MPa.
This is the most excellent aluminum interface strength.

[0018]

According to the present invention, bending test pieces were cut out from the test pieces obtained in the examples, and the strength of the test pieces was evaluated. All the test pieces were significantly plastically deformed on the aluminum side, and the strength could not be evaluated.
It is concluded that the conjugate has sufficient strength. Therefore, according to the present invention, when joining alumina ceramics and aluminum, an aluminum alloy containing a specific amount of Si is interposed, or a titanium hydride paste or Cu is screen-printed on alumina ceramics in advance and metallized, and a vacuum is applied. 590 ° C-600 in
200MPa on average by joining by heating to
As described above, under preferable conditions, the average is 250 MPa even higher.
With the above, the joint strength that reaches the base metal strength is obtained, and it is most suitable for joining aluminum and alumina ceramics that require the strength and reliability of the joint as a structural component.

Claims (3)

(57) [Claims] An alumina ceramic material and Si0.6
wt% or less, Fe 0.7 wt% or less, Cu 0.2 wt%
Hereinafter, for bonding with an aluminum material containing not more than 2.0 wt% of Mn, 9.0 wt% to 11.0 wt% of Si, Fe
0.8 wt% or less, Cu 0.3 wt% or less, Mn0.0
5 wt% or less, Mg0.05 wt% or less, Zn0.1w
t% or less, Ti 0.2 wt% or less, and the remainder substantially made of Al, with an aluminum alloy material interposed therebetween, heated to 590 ° C. to 600 ° C. in a vacuum or an inert atmosphere, and joined.
A method of joining alumina ceramics and aluminum, wherein a joining strength of at least 00 MPa is obtained. 2. The alumina ceramic according to claim 1, wherein a TiH paste is screen-printed in advance on a surface to be joined of the alumina ceramic material and metallized at 900 ° C. to 1000 ° C. in a vacuum. And aluminum joining method. 3. The alumina ceramic according to claim 1, wherein a Cu paste is screen-printed in advance on a surface of the alumina ceramic material to be joined, and metallized at 900 ° C. to 1200 ° C. in a vacuum. And aluminum joining method.