JPS63190788A - Ceramics metallization method - 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 metallizing ceramics. More specifically, the present invention relates to oxides, carbides, borides, AIN,
The present invention relates to a method of metallizing the surface of a ceramic made of TiN, BN, or a composite thereof to form a metallized surface that can be suitably used for joining the ceramic to a metal member or other ceramic member.

Conventional ■ Construction The metallization method of ceramics is a method of forming a metal layer on the surface of ceramics. Metallizing the surface of ceramics in this way is useful for high-strength bonding of ceramics, such as bonding conductive wires and heat dissipation fins to ceramic substrates in electronic components, or bonding metals or ceramics to each other in structural parts and engine parts. This is the process necessary to obtain .

Typical metallization methods include molybdenum-manganese method,
There are active metal methods and oxide solder methods. this house,
In the active metal method, materials such as Ti and Zr become active at high temperatures,
This method uses active metals that easily react with ceramics. That is, this is a method in which a plate or foil-shaped active metal is inserted between the ceramic and the sealing metal, and the ceramics and the sealing metal are heat-treated in a vacuum or an inert gas to seal them.

Nikkei Mechanical (NIKKEI MEC) IANICA
L) 1986.1.13 describes a method for active metal brazing. This active metal brazing method uses a brazing filler metal and an active metal, and either a foil of the brazing filler metal is used together with the active metal, or the active metal is mixed into the brazing filler metal. Also disclosed is a method in which powder of an active metal such as Ni is sprinkled on the surface of a ceramic such as S i 3 N 4 and metallized by heating under vacuum.

As mentioned above, the conventional methods of metallizing ceramics with active metals include methods using alloy brazing filler metals mixed with active metals, and methods of bonding them in the form of foils or plates. is proposed. However, in these methods, highly pure active metals cannot be used, and the activity is lowered due to contamination with impurities.

On the other hand, because of their high activity, active metals are susceptible to corrosion such as oxidation, so there is a problem in that their high activity cannot be utilized.

In addition, in order to solve these problems, a method has been proposed in which highly purified Ti is deposited on the surface of ceramics using an ion plating method. However, since TiJii deposited by this method is bonded in a solid state, it has poor wettability with respect to ceramics, and there are problems in that the reaction with ceramics does not proceed and the interfacial strength is low.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to form a clean and sound metal layer on the surface of ceramics to provide a strong bonding surface with other metal members or ceramics. .

A further object of the present invention is to provide a simple and economically feasible method for forming metallized surfaces that enable high-strength bonding of metal parts or other ceramic parts.

. The inventors of the present invention studied the problems of the prior art ceramic metallization method described above, and completed the present invention as a result of various experiments and studies.

According to the invention, oxides, carbides, borides, ^IN,
A method for metallizing ceramics is characterized in that two or more metals including an active metal are deposited on the surface of a ceramic made of TiN5BN or a composite thereof by a physical vapor deposition method, and then heat treated at a temperature higher than the melting point of the metal layer. provided.

The heat treatment of the metal layer described above is preferably carried out under vacuum.

The physical vapor deposition method employed in the metallization method of the present invention is preferably an ion plating method or a sputtering method.

In the method of the present invention, two or more metals may be deposited in a sequentially laminated manner, or may be deposited in combination at the same time. Composite deposition refers to the simultaneous deposition of different metals or alloys of different metals.

Furthermore, active metals preferably used in the method of the present invention include Ti, Ni, Zr, Fe5Nb, W,
, Mo.

There are T1, AI, etc.

Further, according to a preferred embodiment of the present invention, the melting point of the vapor-deposited metal layer is 1600°C or less, and the metal layer is heat-treated in vacuum at a temperature slightly higher than the melting point, that is, within a temperature range that does not damage the ceramic. This metallizes the surface of the ceramic.

The effect of each step of the ceramic metallization method of the present invention will be explained.

First, in the method of the present invention, two or more metals containing an active metal are deposited by a physical vapor deposition method such as an ion plating method or a sputtering method, thereby bringing the active metal into contact with the ceramic in a highly active state. This is done by bringing the active metal into contact with the ceramic in a pure state (that is, in a state of high purity and without corrosion such as oxidation) to increase the reactivity as much as possible, while at the same time generating oxides that have a negative impact on the interface. This is to suppress the

For example, in the case of Ti, the generation of Ti01TiO2 is a major cause of a decrease in the strength of the interface, but physical vapor deposition suppresses their generation and allows the active metal to be vapor-deposited in a highly active and clean state.

Furthermore, in the present invention, two or more metals including an active metal are vapor-deposited to form a metal layer. This is because when a layer of two or more metals is formed and heated, these metals form a eutectic alloy, which significantly lowers the melting point. In other words, as in the prior art, active metal alone has a very high melting point, and when heated and melted, the temperature becomes high and there is a risk of damaging the ceramics, but with the method of the present invention, it can be heated and melted even at low temperatures, so there is no damage to the ceramics. I can't see it. Therefore, in a preferred embodiment of the present invention, the melting point of the metal layer is set to 1600''C or less. Two or more metals may be laminated one after another, or may be compositely deposited at the same time.

Next, the two or more metal layers deposited are heat-treated at a temperature higher than their melting point, and reacted with the ceramic in a molten state. This improves wettability by bringing the metal layer into contact with the ceramic in a molten state, increasing the contact area between the ceramic and the active metal, making it possible to make the most of the activity of the active metal, and This is because a strong reaction layer can be formed. In this way, wettability with respect to ceramics is improved compared to reacting in a solid state, and the reactivity of the active metal can be maximized due to the synergistic effect of forming a metal layer by physical vapor deposition. In addition, since the deposited metal is melted and heated, it becomes a molten liquid and reacts uniformly with the ceramic, making it possible to obtain a stable interfacial strength without variation.

Furthermore, it is preferable to carry out the heating and melting treatment under vacuum because the activity of the active metal is not impaired and a bonding interface with even higher strength can be obtained.

The heat treatment temperature for these metal layers is preferably 1600°C or lower in order to control excessive reaction of the active metal and to prevent deterioration of the ceramic itself. The metal group to be deposited is selected so that the temperature is below ℃.

Hereinafter, the present invention will be explained with reference to Examples, but these Examples are merely illustrative of the present invention, and of course do not limit the technical scope of the present invention.

ZrO partially stabilized by adding Y2O3 on Tsimchuan coal, and 1
ZrO□ with dimensions 0inX1 (lnX 1 ax
The ceramic test piece was cleaned with acetone and trichlene in an ultrasonic cleaner to remove oil and water. Next, according to the present invention, Ti, Cu, and Ag are deposited in layers using an ion plating device, and then heat treatment is performed at 830°C, which is higher than the melting point of the entire metal layer, to metallize the surface of ZrO and ceramics. did.

For comparison, the same ZrO and test pieces as above were used, respectively.
A Ti-Cu-Ag alloy brazing filler metal is placed and heat treated at 830"C for metallization, or a Ti foil (0.2 mm
(purity 99.0%) was placed on the test piece, and Cu
-Ag alloy brazing filler metal was placed on it, and heat treatment was performed at <830° C. as in the above-mentioned example of the present invention to metallize it. Furthermore, Ti and Ni minnows (1 Tsuru thickness purity 99.5%) were heated to 1200°C.
Metallization was performed by joining the above test piece under a pressure of 15×10-'Torr and 100 kg/cal.

The metallized surfaces of these examples of the present invention and comparative examples were joined to SUS wire using solder, and the tensile strength of the joints was measured.

The results are shown in Table 1.

As is clear from the results shown in Table 1 of the JL Table, when Ti, Cu and Ag are deposited in layers according to the method of the present invention and heated and melted at 830°C, a metallized surface with extremely high bonding strength can be obtained.

Further, under the same conditions as above, metal layers of Ti, Cu, and Ag were deposited on ZrO2 specimens using an ion plating device, and were heat-treated at various temperatures up to 1800"C while remaining untreated. A wire was bonded to the surface of the coating layer by soldering, and the tensile strength of the bonded portion was measured.The results are shown in Table 2.

Table 2 * ZrO□ Alteration Strength Decrease As is clear from the results in Table 2, the metallized surfaces heated and melted at a temperature equal to or higher than the melting point of the entire laminated metal layer according to the method of the present invention have high bonding strength. On the other hand, as the heating melting temperature increases beyond the melting point of the entire metal layer, the bonding strength decreases. This is thought to be because ceramics are damaged as the temperature increases.

1) Crude purity 99.0% (X Altos, 20mX
The surface of an AhOz ceramic test piece having dimensions of 20 m x 5 fins was washed with acetone in an ultrasonic cleaner for 10 minutes, and then with trichlene for 10 minutes. Then, according to the present invention, Ni and Cu are deposited in 1.0 parts each using an ion plating apparatus.
Vapor deposition was performed in a stacked state of 5 μm. The evaporation conditions at this time were: vacuum level inside the device: 3 x 1O-6 Torr, substrate temperature: 400
'C, and Ni and Cu were ionized and deposited using radio frequency. The melting point of the entire metal layer was measured to be 1230°C.

Next, A1.Ni and Cu thus obtained were deposited. O, the test piece was introduced into the heating furnace and heated at various temperatures for 1
The metal layer and the ceramic substrate were allowed to react for 0 minutes. In order to measure the adhesive strength of the metallized surface thus formed, wires were bonded by soldering and the tensile strength thereof was measured. The results are shown in Table 3.

As is clear from Table 3, the melting point of the metal layer (1230°C)
In the treatment at the above heating temperature, the bonding strength increases rapidly, and when the heating temperature reaches a high temperature around 1600° C., it decreases significantly. This is because heating above 1230°C melts the metal layer and the reaction between the ceramic substrate and the active metal progresses sufficiently, resulting in an increase in bonding strength.
It is thought that this is because the ceramic substrate deteriorates when the temperature exceeds 0''C.

The surface of a ZrB2 ceramic test piece having dimensions of 10 l, 10 mm x 10+ u was washed with acetone and trichloride in an ultrasonic cleaner for 10 minutes each to remove oil and moisture from the surface. Next, using an ion plating device, 0.5 μm of Zr and 1.5 μm of Ni were deposited on the surface of the test piece.
Vapor deposition was performed in a μm stacked state. At this time, the degree of vacuum inside the device is 3
Xl0-6 Torr, the substrate temperature is 300"C,
Zr and Ni were ionized and deposited using high frequency.

The melting point of these metal layers as a whole was measured and found to be 1080°C. The ZrB test piece on which Zr and Ni had been vapor-deposited was introduced into a heating furnace, and untreated and heated to various temperatures up to 1300'C and held for 10 minutes to cause the metal layer and the ceramic substrate to react. In order to measure the strength of these joints, we bonded the wires by soldering and
Their tensile strength was measured.

The results are shown in Table 4.

■↓1 In this example as well, when the metal layer is heated at a temperature exceeding the melting point of 1080''C, the metal layer melts and the active metal contained therein reacts sufficiently with the ceramics, resulting in high bonding strength.

Si and Fe were deposited in layers of 1.0 μm each by sputtering on a substrate of a SiC hot press sintered body having dimensions of 10 dragons x 10 u + X O, 5 cranes. Next, metallization treatment was performed by heating under vacuum to a temperature of 1250° C. or higher, which is the melting point of the entire metal layer.

A heat dissipating fin made of Cu was bonded to this metallized surface.

The resulting joined body exhibited good properties, with no cracks at all at the joint, and a strong interface was formed.

Example 5 It has dimensions of 10m, x 10mm x O, 5cm,
Using an ion plating device, 0.5% each of Ti and Cu was applied to the ^IN substrate of the pressureless sintered body of the doctor blade.
Laminated deposition was performed in μm increments. As for the deposition conditions, the degree of vacuum was 5×10 −6 Torr, the substrate temperature was 500° C., and Ti and Cu were ionized using high frequency. An Au wire was placed on the vapor-deposited surface of the sample after vapor deposition, and the sample was heat-treated in a vacuum at various temperature ranges in a heating furnace to perform bonding. The bonding strength of the Au wire at this time was evaluated by a tensile strength test, and the results are shown in Table 5.

Table 5* Even in this example in which the AIN surface layer is significantly altered, the bonding strength of the metallized surface obtained by heat treatment at a temperature higher than the melting point of the metal layer is extremely excellent. Moreover, when heated to 1800° C., the quality of the AIN ceramic changes and the bonding strength also decreases.

A mixture of Nb and Ni was compositely deposited to a thickness of 2 μm on a BN ceramic substrate using magnetron sputtering. The melting point of the metal layer thus formed is 123
0''C. Next, heat treatment was performed at 1300°C using a vacuum furnace.

On the other hand, for comparison, Nb foil and Ni foil (each 1 piece thick) were used in B above.
The Nb foil was stacked on the N substrate with the Nb foil facing down, and heat treatment was performed at 1350°C using a heating furnace (the melting point of the entire Nb foil and Nu foil was 1320°C).

Those that were heat-treated after vapor deposition using the magnetron sputtering method formed a uniform and strong bonding interface, whereas those that used Nb foil and Ni foil had weak bonding interface strength and the foils easily peeled off. Ta.

As explained above, the method for metallizing ceramics of the present invention is much more effective than conventional methods in forming metallized surfaces of oxide, carbide, boride, AIN, TiN, or BN ceramics. This has significantly improved strength and achieves homogeneous bonding.

Therefore, when the metallization method of the present invention is utilized in the fields of joining various parts in ceramic electronic parts, and joining metals and ceramics in structural parts and engine parts,
Ceramics can now be used in areas subject to high loads that were previously not possible.

Claims (5)

[Claims] (1) Oxide, carbide, boride, AIN, TiN, B
A ceramic metal characterized by depositing two or more metals including an active metal on the surface of a ceramic made of N or a composite thereof by a physical vapor deposition method, and heat-treating at a temperature equal to or higher than the melting point of the formed metal deposited layer. cation law. (2) The method for metallizing ceramics according to claim 1, wherein the physical vapor deposition method is an ion plating method or a sputtering method. (3) The method for metallizing ceramics according to any one of claims 1 to 3, wherein the melting point of the deposited metal layer is 1600°C or less. (4) The method for metallizing ceramics according to any one of claims 1 to 4, characterized in that two or more of the metals are deposited in a layered manner. (5) The method for metallizing ceramics according to any one of claims 1 to 4, which comprises performing composite vapor deposition of two or more metals.