JPH10194860A - Brazing filler metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve wettability and to enhance joining strength to ceramics in a brazing filler active metal for joining a ceramic to a metal or joining ceramics to each other. SOLUTION: In the brazing filler metal, an intermetallic compound consists of Ti, Zr, Hf which are group IVa elements and other metals and the group IVa elements form a solid soln. with at least one kind of nonmetallic element selected from oxygen, nitrogen and carbon. The brazing filler metal is supplied to a joining part between the ceramic and the metal, etc., in a shape of powder, foil, thin film, etc. Further, the brazing filler metal can be obtained by alloying the solid soln. between the group IVa elements and nonmetallic elements described above and a metal such as Ag, Cu and Ni.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active metal brazing material used for sealing and joining ceramic and metal or between ceramics.

[0002]

2. Description of the Related Art Conventionally, as a method of sealing and joining a ceramic base material and a metal base material or ceramic base materials, Mo-Mn method (high melting point metal method), DBC (Dirty metal method), and the like have been known.
(Elect Bonding Cupper) method, active metal method and the like are known, and are applied to a wide range from joining of functional materials such as semiconductor devices to joining of structural materials such as gas turbines. Among these joining methods, the Mo-Mn method and the DBC method are members in which the mechanical strength, for example, the tensile strength of the obtained joined body is lower than the strength of the base material, so that the strength and the heat fatigue resistance are required. Not only is it difficult to apply the method, but also there is a problem that a joining process such as a step of forming a metallized layer is complicated.

[0003] On the other hand, the active metal method uses the reducing action of Ti or Zr, which is an active metal, on ceramics to perform bonding by a high chemical bonding force at the interface. This has the advantage that a joined body having higher mechanical strength can be obtained as compared with the method and the joining process is simple.

[0004]

However, even in the active metal method described above, further improvement of the brazing material is desired in order to reduce the amount of the brazing material to be used and to perform the joining efficiently. That is, there is a demand for a brazing material having better wettability to ceramics than a conventional brazing material in which Ti in a solid solution range is added to an alloy such as Ag-Cu having a eutectic composition.

The present invention has been made in view of such a demand, and an object of the present invention is to provide an active metal brazing material for bonding having improved wettability to ceramic.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, although metals generally have poor wettability with ceramics and do not spread on the ceramic surface. On the other hand, since the ceramic brazing material represented by glass solder spreads well on the ceramic without any chemical reaction, the active metal brazing material contains oxygen or the like as a group 4a element that reacts with the ceramic. It has been found that wettability can be improved by positively dissolving the solid to create a state close to ceramic.

The brazing material of the present invention has been made based on such findings, and the intermetallic compound comprising a Group 4a element and another metal, and a Group 4a element selected from oxygen, nitrogen and carbon. It is characterized in that it forms a solid solution with at least one nonmetallic element.

The brazing material of the present invention comprises, for example, at least one metal element selected from Ti, Zr and Hf which are Group 4a elements, and at least one nonmetal element selected from oxygen, nitrogen and carbon. Can be obtained by alloying the above-mentioned solid solution with another metal which forms an alloy having a relatively low melting point with the above-mentioned Group 4a element. Here, as other metals, Ag, Cu, Ni, Co, Cr, Fe, Mn,
One or more metals selected from Ag-Cu alloy and Au-Cu alloy can be used.

The brazing material of the present invention is in the form of a powder, a foil, a thin film laminate or the like, and is used for sealing and joining ceramic and metal or ceramics. Here, examples of the ceramic include oxide ceramics such as alumina, magnesia, and silica; nitride ceramics such as silicon nitride and aluminum nitride; and carbide ceramics such as silicon carbide. In particular, in a brazing material in which a Group 4a element (including an intermetallic compound of a Group 4a element and another metal) such as Ti, Zr or Hf forms a solid solution with oxygen, an oxide-based ceramic and a metal etc. Suitable for sealing joining. Similarly, a brazing material in which a Group 4a element forms a solid solution with nitrogen is suitable for joining a nitride-based ceramic to a metal or the like.
A brazing material in which a group a element forms a solid solution with carbon is suitable for joining a carbide-based ceramic to a metal or the like.

[0010] Among the brazing materials of the present invention, a brazing material containing a solid solution of a Group 4a element and oxygen is supplied to the above-mentioned joint between the oxide-based ceramic and a metal or the like, and is then placed in a vacuum or in an inert gas. When heated and melted in a non-oxidizing atmosphere such as
A solid solution of a Group 4a element and oxygen having a structure close to that of an oxide-based ceramic wets and spreads well on the surface of the ceramic. In addition, since the solid solution itself of the Group 4a element and oxygen has a strong affinity for oxygen and chemically reacts with the oxide-based ceramic, good bonding can be performed. Also,
When a brazing filler metal containing a solid solution of a Group 4a element and nitrogen is supplied to a joint between a nitride ceramic and a metal and heated and melted, a solid solution of a Group 4a element and nitrogen is formed on the surface of the nitride ceramic. And wet-spread and diffuse, and chemically react with the nitride-based ceramic, so that good bonding can be obtained. Similarly, a brazing material containing a solid solution of a 4a group element and carbon is used as a carbide-based ceramic. When supplied to a joint with a metal or the like and melted by heating, a solid solution of a 4a group element and carbon spreads and spreads on the surface of the carbide-based ceramic,
In addition, since it chemically reacts with the carbide-based ceramic, good joining can be obtained.

[0011]

Embodiments of the present invention will be described below.

In the brazing material of the present invention, the periodic table 4a
At least one metal element selected from the group consisting of Ti, Zr, and Hf, or an intermetallic compound of these elements and another metal, and at least one non-metal element selected from oxygen, nitrogen, and carbon. It contains a solid solution with a metal element, and is used for sealing and joining ceramics to metals or ceramics in the form of a powder, foil, thin film laminate, or the like.

For example, in an Ag-Cu-Ti brazing material, an Ag-Cu alloy and oxygen-dissolved Ti (a solid solution of Ti and oxygen) are formed into powder, foil, thin film, etc., respectively, to form a ceramic material. It can be supplied to a joint with a metal or the like. Here, as a solid solution of Ti and oxygen, Ti
A solid solution having a composition formula such as ₂ O, Ti ₃ O ₂ , and TiO can be given. These solid solutions have an atomic ratio of Ti to oxygen (Ti: O) of 1: 1 or more, and have sufficient metallicity. Similarly, Ag-Cu-Zr-based or Ag-Cu-Hf-based brazing filler metals
A Cu alloy and a solid solution having a high metallicity of Zr or Hf and oxygen (atomic ratio of 1: 1 or more) can be supplied to the joint in the form of a foil, a powder, a thin film, or the like.

In the brazing material of the present invention, the content ratio of the nonmetallic element such as oxygen to the whole brazing material is 1% by weight (wt.
%) Or more, more preferably 5% by weight or more. If the content ratio of oxygen and the like is less than 1 wt% of the whole brazing material, the effect of improving the wettability to the ceramic hardly appears.

When such a brazing material is inserted into the joint and melted by heating, a solid solution (eg, Ti ₂ O, Ti ₃ O ₂ ) of the Group 4a element and oxygen in the brazing material wets the ceramic surface. Spread and spread. Further, Ti ₂ O, Ti ₃ O _{2, and the} like themselves have a strong affinity for oxygen, and thus chemically react with an oxide-based ceramic at the interface to form a good bond.

The brazing material according to the present invention comprises at least one metal element selected from the group 4a elements Ti, Zr and Hf, or an intermetallic compound of these with other metals, oxygen, nitrogen and carbon. A solid solution with at least one non-metallic element selected from the group consisting of Ag, Cu, Au, Ni, Co, C
It can be obtained by alloying with at least one metal or alloy selected from r, Fe, Mn, Ag-Cu and Au-Cu. In such a brazing material, the content ratio of oxygen (hereinafter, oxygen will be described, but the same applies to the case where nitrogen or carbon is included) is desirably 1 wt% or more based on the entire brazing material. Preferably, it is at least 5 wt%. Further, the amount of oxygen in the solid solution of the Group 4a element and oxygen is not particularly limited. However, from the viewpoint of the wettability of the brazing material to be obtained, it is preferable to form a solid solution of oxygen to the full solid solution limit.

For example, in a binary brazing material such as Cu-Ti or Ni-Ti, oxygen can be dissolved up to 15 at% (atomic%) in a solid solution of Ti and oxygen. , A substance having a composition formula such as Cu ₂ Ti ₄ O or Ni ₂ Ti ₄ O can be used.

As a method for obtaining such an alloy-based brazing material, there is a method of using a solid solution of a Group 4a element in which oxygen is dissolved in advance and mixing it with another metal element to form an alloy. And a method of dissolving oxygen in a process of mixing a Group 4a element with the metal element. The alloying method is not particularly limited as long as a brazing material containing a solid solution of a Group 4a element and oxygen can be finally obtained. Examples of the solid solution of the Group 4a element in the former method include an α-Ti oxygen solid solution, a solid solution having the composition formulas TiO, Ti ₂ O, and Ti ₃ O ₂ , an α-Zr oxygen solid solution, and an α-Hf
Oxygen solid solution and the like can be mentioned. In the latter method, as a method of mixing a 4a group element with another metal element, there are an arc melting method, a mixing method using a ball mill, a mechanical alloying method, and the like. Oxygen can be dissolved in the element. In the arc melting method, Ti and an oxide such as Ti ₂ O ₃ and TiO ₂ are pelletized and dissolved with an alloy element so that the Ti powder is contained at a mixing ratio of 1: 1 or more, so that oxygen is solidified. Soluble Ti can be obtained. In the ball milling method, alloying can be performed while slightly incorporating oxygen existing in the atmosphere by mixing alloying elements in the atmosphere with high energy using a planetary ball mill.

[0019]

Next, specific examples of the present invention will be described.

Example 1 A Ti foil was placed in a low oxygen atmosphere of 1 × 10 ⁻⁵ Torr for 3 hours for 6 hours.
Heat treatment at a temperature of 73 ° K allows a 1 μm thick T
An oxygen-dissolved Ti foil containing i ₂ O was obtained. Then purity
On the surface of a substrate made of 99% Al ₂ O _3, an oxygen solid solution Ti foil containing Ti ₂ O of Ag one Cu eutectic alloy foil and the thickness 1μm thick 50 [mu] m, an area of 100 mm ² Place them in a vacuum furnace and place them at a heating rate of 0.25 K / sec.
The temperature was raised to 23 ° K. When the temperature reaches 1123 ° K, Al
_When the wetting angle (contact angle) of the brazing material on the surface of the ₂ O ₃ substrate was measured, it was 6 °.

Also, a disk-shaped Ag-Cu eutectic alloy foil (thickness: 50 μm) having a diameter of 5 mm and the oxygen-solid Ti (Ti ₂ O)
A foil (1 μm) is placed on the Al ₂ O ₃ substrate, and a pin made of Fe-42Ni with a diameter of 2 mm is placed at the center of the disc on the Al ₂ O ₃ substrate. Temperature, held at that temperature for 5 minutes, and then cooled in the furnace,
The Al ₂ O ₃ base material and the Fe-42Ni pin are well sealed and joined, the joint area is the area of a circle with a diameter of 5 mm (19.6 mm ² ) occupied by the brazing material at the beginning, and the joint strength is 98 kgf. there were.

On the other hand, as Comparative Example 1, Al ₂ having a purity of 99% was used.
_On a surface of an O ₃ substrate, a 50 μm thick Ag-Cu eutectic alloy foil and a conventional 1 μm thick Ti foil were placed in an area of 100 mm ² , and this was placed in a vacuum furnace. The temperature was raised to 1123 ° K at the same temperature raising rate as that of 1, and when the temperature reached 1123 ° K, the wetting angle of the brazing material on the surface of the Al ₂ O ₃ base material was measured to be 10 °.

Further, a disc-shaped Ag-Cu eutectic alloy foil (thickness: 50 μm) having a diameter of 5 mm and a conventional Ti foil (1 μm) were formed by A
L ₂ O ₃ Substrate is overlaid on it, and 2mm diameter Fe-42Ni
The manufacturing of the pin disposed in the center of the disc, the temperature was raised to 1123 ° K in a similar manner to put the whole in a vacuum furnace, it was maintained at that temperature for 5 minutes, was cooled as it furnace, Al ₂ O ₃ group Material and Fe
It was joined to the -42Ni pin, but the joint area was smaller than the area of the 5mm
mm (5.39 mm ² ), and the joint strength was 26.95 kgf.

Thus, it can be seen that the brazing material of Example 1 has higher wettability to Al ₂ O ₃ than the brazing material of Comparative Example 1, and a good sealing joint with high airtightness can be obtained. Was.

Example 2 Ti foil was placed in a low oxygen atmosphere of 1 × 10 ⁻⁵ Torr for 2 hours for 7 hours.
Heat treatment at a temperature of 73 ° K allows a 1 μm thick T
A foil containing i ₃ O ₂ was obtained. Then, 96% pure Al
_A 50 μm thick Ag-Cu eutectic alloy foil and a 1 μm thick oxygen-dissolved Ti foil containing Ti ₃ O ₂ were placed on the surface of a ₂ O ₃ substrate in an area of 100 mm ² , This was heated in a vacuum furnace to 1123 ° K at a rate of 0.25 ° K / sec. 11
When the temperature reached 23 ° K, the wetting angle of the brazing material on the surface of the Al ₂ O ₃ substrate was measured and found to be 7 °.

Further, a disk-shaped Ag-Cu eutectic alloy foil (thickness: 50 μm) having a diameter of 5 mm and the oxygen-dissolved Ti (Ti
₃ O ₂ ) foil (1 μm) and an Al ₂ O ₃ substrate
A 2 mm diameter Fe-42Ni pin was placed on the center of the disk, and the whole was placed in a vacuum furnace, heated to 1123 ° K in the same manner, and kept at that temperature for 5 minutes. When cooled, the Al ₂ O ₃ base material and the Fe-42Ni pin were sealed and joined well, and the joint area was the diameter occupied by the brazing material initially.
4.5mm circle area (15.9mm ² ), bonding strength 80kg
f.

On the other hand, as Comparative Example 2, Al ₂ O having a purity of 96% was used.
_{(3) On} a surface of the base material, a 50 μm-thick Ag-Cu eutectic alloy foil in which oxygen is dissolved to the full solid solution limit and a 1 μm-thick Ti foil are placed in an area of 100 mm ^{2 in} an overlapping manner. Was heated to 1123 ° K in a vacuum furnace at the same heating rate as in Example 1,
When the temperature reached 1123 ° K, the wetting angle of the brazing material on the Al ₂ O ₃ substrate surface was measured and found to be 15 °.

As described above, the brazing material of Example 2 in which oxygen was dissolved in the Ti side, which is a Group 4a element, compared with the brazing material of Comparative Example 2 in which oxygen was dissolved in the eutectic alloy side. Al ₂ O ₃
It has been found that a good joint having high wettability with respect to water and high airtightness can be obtained.

Example 3 Ag-Cu eutectic alloy powder and Zr-oxygen solid solution powder containing 15 at% of oxygen were mixed in an organic binder so that the weight ratio of Ag: Cu: Zr was 70: 27: 3. And 1 g of the obtained brazing material was applied to the surface of an Al ₂ O ₃ substrate having a purity of 99%. Next, the Al ₂ O thus coated with the brazing material
_{(3) The} substrate is heated to 1123 ° at a rate of 0.25 ° K / sec in a vacuum furnace.
K, and when it reaches 1123 ° K, Al ₂ O ₃
When the wetting angle of the brazing material on the substrate surface was measured, 8 °
Met.

Further, 10 mg of a mixed powder of the Ag-Cu eutectic alloy and the oxygen-dissolved Zr was placed on an Al ₂ O ₃ substrate with a diameter of 5 mm.
Apply a 2mm diameter Fe-42Ni pin on the center of the circle, put the whole into a vacuum furnace and do the same.
After the temperature was raised to 1123 ° K, the temperature was held for 5 minutes, and the furnace was cooled, the Al ₂ O ₃ base material and the Fe-42Ni pin were bonded and bonded well, and the bonding area was the brazing material first. The area occupied by a circle having a diameter of 5 mm (19.6 mm ² ) and the joint strength was 78 kgf.

On the other hand, as Comparative Example 3, Ag-Cu eutectic alloy powder and Zr powder were mixed at a weight ratio of Ag: Cu: Zr of 70:
1 g of the brazing material obtained by mixing in an organic binder to give a ratio of 27: 3 was applied to the surface of a 99% pure Al ₂ O ₃ substrate. Next, the Al ₂ coated with the brazing material
The O ₃ substrate was heated at 1123 ° K. in a vacuum furnace in the same manner as in Example 3.
When the temperature reached 1123 ° K, the wetting angle of the brazing material on the Al ₂ O ₃ substrate surface was measured and found to be 15 °.

Further, 10 mg of a mixed powder of an Ag-Cu eutectic alloy and ordinary Zr is applied in a circular shape having a diameter of 5 mm on an Al ₂ O ₃ substrate, and a pin made of Fe-42Ni having a diameter of 2 mm is formed thereon. At the center of the circle, put the whole in a vacuum furnace and
After raising the temperature to K, holding at that temperature for 5 minutes, and then cooling the furnace as it was, the Al ₂ O ₃ substrate was joined to the Fe-42Ni pin, but the brazing material occupied the joint area first. Less than the area of a 5mm diameter circle, about 3mm in diameter (5.39m
m ² ), and the joining strength was 28.26 kgf.

Thus, it was found that the brazing material of Example 3 had higher wettability to Al ₂ O ₃ than the brazing material of Comparative Example 3, and a good joint was obtained.

Example 4 A solid solution of Ti and oxygen was mixed with Cu, and Cu: Ti: O was 1
5: 5: 1 atomic ratio was mixed and alloyed.
Thickness 10 [mu] m, the foil-like brazing alloy material of area 100 mm ^2, purity
This was placed on the surface of a base material made of 96% MgO, and this was heated to 1173 ° K in a vacuum furnace at a rate of 0.25 ° K / sec. When the temperature reached 1173 ° K, the wetting angle of the brazing material on the MgO substrate surface was measured and found to be 10 °.

A disk-shaped Cu-Ti-O having a diameter of 5 mm
Place the alloy foil (thickness 10μm) on the MgO substrate and place a 2mm diameter Fe-42Ni pin on the MgO substrate at the center of the disk.
Put the whole in a vacuum furnace and raise the temperature to 1173 ° K in the same way,
After holding at that temperature for 5 minutes and then cooled in the furnace, the MgO base material and the Fe-42Ni pin were well sealed and joined, and the joining area was the area of the 5 mm diameter circle initially occupied by the brazing material ( 19.6 mm ² ) and the bonding strength was 117 kgf.

As Comparative Example 4, Cu: Ti is 15: 5
Alloyed to have an atomic ratio of 10 μm in thickness and 1 in area
A Cu-Ti alloy brazing material in the form of a 00 mm ² foil was
This was placed on the surface of the gO substrate, and the temperature was raised to 1173 ° K in a vacuum furnace in the same manner as in Example 4. When the temperature reached 1173 ° K, the wetting angle of the brazing material on the MgO substrate surface was changed. It was 16 ° when measured.

Further, a disk-shaped Cu—Ti alloy foil (thickness: 10 μm) having a diameter of 5 mm is placed on an MgO substrate, and a pin made of Fe-42Ni having a diameter of 2 mm is placed at the center of the disk. The whole was put in a vacuum furnace, heated to 1173 ° K in the same manner, kept at that temperature for 5 minutes, and then cooled in the furnace as it was.
Although the gO base material and the Fe-42Ni pin were joined, the joining area was smaller than the area of the 5 mm diameter circle occupied by the brazing material initially, and was about 3 mm in diameter (5.39 mm ² ).
It was 0 kgf.

As described above, it was found that the foil alloy brazing material of Example 4 had higher wettability to MgO than that of Comparative Example 4, and a good joint was obtained.

Example 5 A solid solution of Ti and oxygen and Ni were Ni: Ti: O.
Mixed and alloyed to give an atomic ratio of 2: 4: 1,
Thickness 10 [mu] m, the foil-like brazing alloy material of area 100 mm ^2, purity
It was placed on the surface of a 96% MgO substrate, and this was placed in a vacuum furnace at 0.
The temperature was raised to 1223 ° K at a rate of 25 ° K / sec. 1223 °
When reaching K, the wetting angle of the brazing material on the surface of the MgO substrate was measured and found to be 13 °.

Also, a disk-shaped Ni-Ti-O having a diameter of 5 mm is used.
Place the alloy foil (thickness 10μm) on the MgO substrate and place a 2mm diameter Fe-42Ni pin on the MgO substrate at the center of the disk.
Put the whole in a vacuum furnace and raise the temperature to 1223 ° K in the same way,
After holding at that temperature for 5 minutes and then cooled in the furnace, the MgO base material and the Fe-42Ni pin were well sealed and joined, and the joining area was the area of the 5 mm diameter circle initially occupied by the brazing material ( 19.6 mm ² ) and the joint strength was 88.2 kgf.

As Comparative Example 5, Ni: Ti is 2: 4
Alloyed to have an atomic ratio of 10 μm in thickness and 1 in area
00mm ² foil Ni-Ti alloy brazing material
This was placed on the surface of the gO base material, and the temperature was raised to 1223 ° K in a vacuum furnace in the same manner as in Example 5. When the temperature reached 1223 ° K, the wetting angle of the brazing material on the MgO base surface was changed. It was 20 ° when measured.

Further, a disk-shaped Ni-Ti alloy foil (thickness: 10 μm) having a diameter of 5 mm is placed on an MgO substrate, and a pin made of Fe-42Ni having a diameter of 2 mm is placed at the center of the disk. The whole was put in a vacuum furnace, heated to 1223 ° K in the same manner, kept at that temperature for 5 minutes, and then cooled in the furnace.
Although the gO base material and the Fe-42Ni pin were joined, the joining area was smaller than the area of the 5 mm diameter circle occupied by the brazing material initially, and was about 3 mm in diameter (5.39 mm ² ).
It was 5 kgf.

As described above, it was found that the foil alloy brazing material of Example 5 had higher wettability to MgO than that of Comparative Example 5, and a good joint was obtained.

Example 6 Al ₂ O was introduced into a chamber at a pressure of 5 × 10 ^-3 Torr while flowing a mixed gas of oxygen and Ar (mixing ratio: 20: 1) at a flow rate of 60 sccm.
_{3 After a} film of Ti was formed to a thickness of 20 nm on the surface of the substrate, an 800 nm Ag-Cu alloy layer was subsequently laminated to form a brazing material layer.

When a pin made of Nb was brought into contact with the surface of the brazing material layer and heat-treated at 1123 ° K. for 10 minutes in a vacuum furnace of 1 × 10 ⁻⁵ Torr, the brazing material was satisfactorily deposited on the Al ₂ O ₃ substrate. The connection with the Nb pin was performed while spreading wet.

On the other hand, as Comparative Example 6, the pressure was 5 × 10 ⁻³ Torr.
While flowing only Ar at a flow rate of 60 sccm into the chamber of
After a 20 nm thick Ti film was formed on the surface of the ₂ O ₃ substrate, an 800 nm Ag-Cu alloy layer was subsequently laminated to form a brazing filler metal layer.
The surface of this brazing material layer is brought into contact with a pin made of Nb,
For 10 minutes in a vacuum furnace of 1 × 10 ^-5 Torr,
The brazing material did not spread and wet and aggregated in an island shape, and the joining could not be performed.

As described above, it was found that the thin film brazing material of Example 1 had better wettability to Al ₂ O ₃ than that of Comparative Example 6, and a good joint was obtained.

[0048]

As described above, the brazing material of the present invention is:
Compared with the conventional active metal brazing material, the wettability to the ceramic at the time of heating and melting is greatly improved. Therefore,
ADVANTAGE OF THE INVENTION According to the brazing material of this invention, the sealing joining of a ceramic and a metal or ceramics can be performed efficiently with a small brazing material amount, and a favorable sealing joining part with high airtightness can be obtained.

[0049]

Claims (2)

[Claims] 1. An intermetallic compound comprising a Group 4a element and another metal, and a Group 4a element forming a solid solution with at least one nonmetallic element selected from oxygen, nitrogen and carbon. Brazing material. 2. The solid solution, Ag, Cu, Ni, C
The brazing material according to claim 1, wherein at least one metal selected from the group consisting of o, Cr, Fe, Mn, an Ag-Cu alloy, and an Au-Cu alloy is alloyed.