JP3012835B2 - Substrate and its manufacturing method, metal joined body suitable for substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate, a method of manufacturing the substrate, and a metal joined body suitable for the substrate.

[0002] The substrate of the present invention is obtained by forming a metal circuit and / or a metal radiator plate on a ceramic substrate. A circuit formed only with a metal circuit or a metal circuit and a metal radiator plate is used as a circuit board, and a plate formed with only a metal radiator plate is used as a heat radiator substrate. The essential difference between the circuit board and the heat dissipation board in the present invention is that no metal circuit is formed on the heat dissipation board. Therefore, the present invention will be described below by taking the circuit board as an example.

[0003]

2. Description of the Related Art In recent years, power modules such as high-power and high-efficiency inverters have been changing with the advancement of the performance of industrial equipment such as robots and motors, and the heat generated from semiconductor devices has been increasing steadily. I have. In order to efficiently dissipate this heat, various methods have conventionally been used for power module substrates. Especially recently, ceramic substrates with good thermal conductivity have become available,
A structure in which a metal plate such as a copper plate is bonded on the substrate to form a metal circuit and then a semiconductor element is mounted as it is or after performing a process such as nickel plating is being adopted. In this case, there is also a structure in which a metal radiator plate such as a copper plate is formed on the ceramic substrate surface opposite to the metal circuit.

[0004] Such modules were initially used for simple machine tools, but have been used for welding machines, train drives and electric vehicles in recent years, and have been used under more severe environmental conditions. Durability and further miniaturization have been required. Therefore, the ceramic substrate is required to have an increased metal circuit thickness for increasing the current density, and to have improved durability against thermal shock and the like.

[0005]

Conventionally, a general-purpose circuit board has a structure in which a copper circuit is formed on an alumina substrate or an aluminum nitride substrate. In order to improve the performance, a device in which an aluminum circuit is formed on an aluminum nitride substrate has recently been developed. However, since aluminum has inferior electrical properties such as current density to copper, such circuit boards have not been widely used.

The present invention has been made in view of the above, and an object of the present invention is to provide a highly reliable substrate (circuit substrate or heat radiation substrate) having excellent heat cycle resistance.
Another object of the present invention is to provide such a highly reliable substrate for productivity.
It is to provide a process for good manufacturing. Still another object of the present invention is to provide a metal joined body suitable as a metal circuit and / or a metal heat sink of such a highly reliable substrate.

[0007]

That is, the present invention provides a substrate, a method for manufacturing the substrate, and a metal joined body, which have the following gist.

[0008] (Claim 1) A metal is provided on the ceramic substrate.
On a substrate on which a circuit and / or a metal heat sink is formed
Te, the metal circuit and / or the metal heat sink, the first following
Metal-third metal-second metal metal joint (however,
Excludes combinations of metals of the same genus and second metal. )
And the first metal is bonded to the ceramic substrate
In addition, the first metal and the third metal are
An alloy layer a containing a trimetal-1b group metal, a first metal-third metal
Metal—an alloy layer b containing a Group 4b metal, a first metal—third gold
Characterized by being joined via an alloy layer c
Substrate. First metal: aluminum (Al), lead (Pb), platinum
(Pt) and one or more of these metal components.
Metals selected from alloys. Second metal: copper (Cu), silver (Ag), gold (Au), aluminum
Minium (Al) and one or two of these metal components
Metals selected from alloys including the above. Third metal: titanium (Ti), nickel (Ni), zircon
Ium (Zr), molybdenum (Mo), tungsten
(W) and one or more of these metal components
Metals selected from alloys. (Claim 2) The first metal is aluminum and the second metal is d.
2. A copper coated with nickel.
On board. (Claim 3) The thickness of the alloy layer a is 1 to 5 μm and the alloy layer b
Is 3 to 7 μm, and the thickness of the alloy layer c is 4 to 10 μm.
The substrate according to claim 1, wherein the substrate is provided. (Claim 4) The first metal is aluminum and the second metal is aluminum.
Copper, third metal is nickel, group 1b metal is copper, group 4b metal
2. The base according to claim 1, wherein
Board. (Claim 5) The substrate is a power module substrate
The substrate according to claim 1, wherein:

(Claim 6) Metal turn of ceramic substrate
The first metal on the road forming surface and / or the metal radiator plate forming surface
Metal circuit pattern and / or metal heat sink pattern
After joining by the refractory metal brazing method,
The pattern of the second metal different from the first metal
2. The bonding according to claim 1, wherein the bonding is performed via a metal.
Method of manufacturing substrates. (Claim 7) The metal circuit forming surface of the ceramic substrate and
// solid metal plate made of the first metal on the surface where the metal heat sink is formed
After joining by the active metal brazing method,
Solid metal plate with a second metal different from the first metal on the surface
Are bonded through a third metal and then etched.
Forming a metal circuit and / or a metal radiator plate
The method for manufacturing a substrate according to claim 1, wherein (Claim 8) The first metal is aluminum and the second metal
Wherein the genus is nickel-coated copper
Item 8. The method for manufacturing a substrate according to Item 6 or 7. (Claim 9) The thickness of the alloy layer a is 1 to 5 μm and the alloy layer b
Is 3 to 7 μm, and the thickness of the alloy layer c is 4 to 10 μm.
8. The method of manufacturing a substrate according to claim 6, wherein:
Law. (Claim 10) The substrate is a power module substrate.
The substrate according to any one of claims 6 to 9, wherein
Manufacturing method.

(Claim 11) The following first metal-third gold
A metal joined body of the genus-second metal (however, the first metal and the second metal
However, combinations of the same metals are excluded. ) And the first gold
Group and a third metal form a first metal-third metal-1 group metal
Alloy layer a containing the first metal-third metal-4 group metal.
Through an alloy layer b and a first metal-third metal alloy layer c.
A metal joined body characterized by being joined together. First metal: aluminum (Al), lead (Pb), platinum
(Pt) and one or more of these metal components.
Metals selected from alloys. Second metal: copper (Cu), silver (Ag), gold (Au), aluminum
Minium (Al) and one or two of these metal components
Metals selected from alloys including the above. Third metal: titanium (Ti), nickel (Ni), zircon
Ium (Zr), molybdenum (Mo), tungsten
(W) and one or more of these metal components
Metals selected from alloys. (Claim 12) The first metal is aluminum and the second metal is aluminum.
Copper, third metal is nickel, group 1b metal is copper, group 4b metal
12. The gold according to claim 11, wherein is gold.
Genus zygote. (Claim 13) The alloy layer a has a thickness of 1 to 5 μm,
b has a thickness of 3 to 7 μm, and alloy layer c has a thickness of 4 to 10 μm
The metal joined body according to claim 11, wherein (Claim 14) The power module substrate is a metal bonded body.
Used for metal circuits and / or metal heat sinks
The method according to any one of claims 11 to 13, wherein
Metal joints.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in more detail. Since a high voltage and a high current flow in a metal circuit portion of a circuit board of a power module, a copper circuit is mainly used at present. However, there is a problem that the copper circuit is peeled off from the interface of the ceramic substrate due to the thermal stress due to the difference in thermal expansion between the copper and the ceramic because the thermal shock is repeatedly received due to a change in environment during use, heat due to switching, and the like.

The magnitude of the thermal stress due to the difference in thermal expansion between copper and ceramics is determined not only by the coefficient of thermal expansion but also by the mechanical properties of the metal itself, mainly tensile strength and proof stress. Therefore, in order to reduce the thermal stress, a metal having lower tensile strength and proof stress than copper may be used, but a metal having such characteristics and having electrical characteristics comparable to that of copper is currently not available. Does not exist.

The inventors of the present invention have conducted various studies and have found that aluminum is selected as a metal having low tensile strength and proof stress, and is joined to a ceramic substrate to reduce the thermal stress due to the difference in thermal expansion with ceramic. However, copper with good electrical characteristics is superimposed on the aluminum, but nickel and the like are interposed between the two metals so that aluminum and copper do not react and diffuse with each other due to heat at the time of joining. The present inventors have found that a metal circuit can be formed, and have further studied the joining method of these metals, thereby completing the present invention.

The material of the ceramic substrate used in the present invention is silicon nitride, aluminum nitride, alumina or the like, but aluminum nitride is suitable for power module applications. If the thickness of the ceramic substrate is too large, the thermal resistance increases, and if it is too small, the durability is lost.

Further, the surface properties of the ceramic substrate are important, and minute defects and depressions adversely affect the bonding of a metal circuit, a metal radiator plate or a metal plate that is a precursor thereof to the ceramic substrate. It is desirable that the surface be smooth. Therefore, it is preferable that the ceramic substrate has been subjected to a honing process or a polishing process such as machining.

The material of the metal circuit and the metal radiator used in the present invention is a first metal-third metal-second metal bonding.
Body (excluding combinations of the same metal as the first and second metals)
Good. ), And the first metal is bonded to the ceramic substrate. Among them, the power module applications Aluminum - Nickel - metal bonded body of copper are suitable, in particular metal bonded product of aluminum and nickel-coated copper is optimal.

The thickness of each of the first metal, the second metal and the third metal is preferably 30 to 200 μm for the first metal, 100 to 500 μm for the second metal, and 5 to 30 μm for the third metal. In addition, it is desirable that the second metal has a small proof stress, and in particular, that the second metal is less than 50 MPa.

Even in the combination of the first metal, the second metal, and the third metal, the function can be sufficiently ensured without impairing the properties of each metal even after forming the metal joined body. It is preferable that the eutectic point of the first metal and the third metal be higher than the eutectic point of the second metal and the third metal by 150 ° C. or more. Among them, copper in which the first metal is aluminum and the second metal is nickel-coated is optimal. Nickel coating can be performed by plating, sputtering, vapor deposition, or the like, but is preferably plating.

In the present invention, the first metal (for example, aluminum) -third metal (for example, nickel)
-Even in the metal joined body of the second metal (for example, copper), the first metal and the third metal are composed of an alloy layer a containing the first metal-third metal-1b group metal and the first metal-third metal. It is preferable that the alloy layer b containing the trimetal-4b group metal and the alloy layer c of the first metal-third metal are joined via the alloy layer b, thereby sufficiently retaining the thermal stress buffering action of the first metal. As a result, the good electrical conductivity of the second metal can be fully utilized.

It is preferable that these alloy layers are formed mainly in the order of the alloy layer a, the alloy layer b, and the alloy layer c from the third metal side. The thickness of each alloy layer is
Preferably, the alloy layer a has a thickness of 1 to 5 μm, the alloy layer b has a thickness of 3 to 7 μm, and the alloy layer c has a thickness of 4 to 10 μm.

The first metal and the third metal in these alloy layers are preferably the same kind of metal as the first metal and the third metal of the metal joined body, or an alloy containing a common metal component. Further, as the Group 1b metal, copper, gold, silver and the like and alloys containing one or more of these components are used, and among them, copper is preferable. Further, as the 4b group metal,
Silicon, tin, lead and the like and alloys containing one or more of these components are used, with silicon being preferred.

The first metal-third metal joined body joined via the alloy layer a, the alloy layer b and the alloy layer c according to the present invention is novel. This metal bonded body (for example, an aluminum-nickel bonded body) has an impurity of 1b group metal (for example, copper) and 4b group metal (for example, silicon) added to either or both of the first metal and the third metal. .1
About 1.2% by weight, a method in which these metal plates are brought into direct contact with each other and heat-treated, or a first metal plate and a third metal plate that do not contain or contain trace amounts of impurities. In the case of the above, it can be manufactured by a method of heat treatment between both metal plates via a bonding material containing a Group 1b metal and / or a Group 4b metal. As the joining material, a foil or paste containing a Group 1b metal and / or a Group 4b metal is used.

The heat treatment is desirably performed under a vacuum of about 1 × 10 ⁻⁴ Torr, and a furnace such as an infrared heating furnace capable of rapid temperature rise and capable of delicate temperature control is used. desirable. In the heating, the temperature is raised to near the eutectic point of the first metal (for example, aluminum) and the third metal (for example, nickel), and the interface between both metals is slightly melted, and then cooled at a rate of 1 ° C./min or more. In particular,
The temperature is maintained at 620 to 630 ° C. for 5 to 10 minutes, and then cooled. The temperature measurement in this case is performed by bringing the temperature measuring body into direct contact with the metal surface.

The first metal-third metal joint according to the present invention is used, for example, as a material for forming a metal circuit of a substrate and / or a metal radiator plate. In that case, the third metal is further joined to a second metal (eg, copper);
That is, the first metal-third metal-second metal must be a metal bonded body, which is a previously manufactured first metal-third metal metal bonded body (for example, Al-metal).
A method of post-bonding a second metal (e.g., copper) to a Ni metal) or a second metal (e.g., copper) as a third metal when manufacturing a first metal-third metal metal bonded body It can be performed by using a metal coated with a third metal (for example, nickel) by electroless plating, sputtering, vapor deposition, or the like. The joining of the third metal and the second metal can be performed by thermocompression bonding or the like in addition to plating or the like. This method is used when the second metal is post-bonded to the first metal-third metal joint.

The first metal-third metal joint according to the present invention is used not only as a material for forming the above-mentioned metal circuit and / or metal heat sink, but also as a structural material.
In addition, it can be used for various purposes by bonding itself to a ceramic substrate. Further, the first metal-third metal of the present invention
A metal-second metal joint is a metal circuit of a substrate, a metal
It is used as a heat sink.

To manufacture the substrate of the present invention , the first metal
A third metal-second metal joint, a method of etching after forming the first metal in contact with the ceramic substrate, or a metal circuit and / or a heat dissipating metal punched from the metal joint; A method of joining the pattern of the plate to the ceramic substrate (pattern mounting method) is adopted.
In any case, the joining of each metal is performed by the production of the above-described first metal-second metal joint or the first metal-
It can be carried out according to the production of the third metal-second metal joint. The joining between the first metal and the ceramic substrate is performed by an active metal brazing method. The active metal brazing method is described in, for example, Japanese Patent Application Laid-Open No. 60-17776.
No. 4, No. 4,915,537.

In the case where the substrate of the present invention is used for a power module, the most preferable embodiment is that the material of the ceramic substrate is an aluminum nitride substrate and the material of the metal circuit and / or the metal radiator is aluminum-nickel-copper. Aluminum and nickel of the metal bonded body are an aluminum-nickel-copper alloy layer a
And an aluminum-nickel-silicon alloy layer b;
It is joined via an aluminum-nickel alloy layer c. Then, this substrate can form a metal circuit and / or a metal radiating plate by etching a metal bonded body bonded to an aluminum nitride substrate, so that a high-reliability substrate can be mass-produced. The manufacturing method will be described.

First, an aluminum plate containing an appropriate amount of a copper component of a Group 1b metal and a silicon component of a Group 4b metal is joined to an aluminum nitride substrate by an active metal brazing method. Aluminum nitride substrate has a thermal conductivity of 10
A material having a bending strength of 0 W / mK or more and a bending strength of 350 MPa or more is used.

The metal component of the brazing filler metal in the active metal brazing method is preferably one containing aluminum and silicon as main components, and using an active metal as an auxiliary component in order to ensure wettability with the aluminum nitride substrate during melting. The active metal component reacts with the aluminum nitride substrate to form an oxide or a nitride, thereby strengthening the bond between the brazing material and the aluminum nitride substrate. Specific examples of active metals include titanium,
Zirconium, hafnium, niobium, tantalum, vanadium and their compounds. In the present invention, these weight ratios are as follows: 70 to 95 parts of aluminum, 30 to 5 parts of silicon, and 1 to 5 parts of copper.
1 to 30 parts of active metal. The bonding temperature is 600 to 64
0 ° C. is desirable.

Next, a copper plate plated with nickel is joined to the surface of the aluminum plate. In this joining, since the aluminum plate contains an appropriate amount of the copper component of the group 1b metal and the silicon component of the group 4b metal, the two are brought into direct contact with each other,
The heat treatment can be performed.

Next, the obtained aluminum nitride substrate
After printing a UV curing type etching resist on a desired metal circuit and / or a pattern of a metal radiator plate on the surface of the metal bonded body composed of the metal bonded body, etching is performed with a cupric chloride solution to form the metal bonded body. Unnecessary portions of copper and nickel are dissolved and removed, and further, unnecessary portions of aluminum of the etching resist and the metal joined body are removed using a caustic soda solution. Since there is still a residual unnecessary brazing material or a reaction product of the active metal component and aluminum nitride between the metal circuit patterns of the substrate obtained in this manner, it is removed with an ammonium fluoride aqueous solution, and the substrate of the present invention is removed. And

[0032]

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples, Reference Examples, and Comparative Examples .

Examples 1 to 19 Reference Example 1 (Pattern mounting method) Terpineol 1 was added to 100 parts by weight of the brazing filler metal composition shown in Table 1.
5 parts by weight were blended, and a toluene solution of polyisobutyl methacrylate was added and kneaded to prepare a brazing filler metal paste. This brazing material paste was applied to an aluminum nitride substrate (size: 60 mm × 36 mm × 0.65 mm, bending strength: 4
(100 MPa, thermal conductivity: 135 W / mK). The coating amount (after drying) at that time was 3 mg / cm ² .

Next, the first metal (purity of about 99.5%, 56 mm × 3 mm) shown in Table 1 was formed on both sides of the aluminum nitride substrate.
2mm × 0.3mm)
After heating at a bonding temperature shown in Table 1 under a vacuum of a degree of vacuum of 1 × 10 ⁻⁵ Torr or less, it was cooled at a rate of 2 ° C./min.
Next, only the second metal is applied to the surface of the first metal (reference example).
1) or the third metal was integrated with the second metal by the method shown in Table 1 (Examples 1 to 19), and they were joined to produce a substrate. The furnace was an infrared heating furnace, and the temperature was measured by bringing a temperature measuring body into contact with a metal surface.

Example 20 (Etching method) An aluminum foil (purity 99.5%, 6%) was coated on both sides of the aluminum nitride substrate on which the brazing filler metal paste of Example 2 was applied.
0mm x 36mm x 0.1mm)
Degree of vacuum 1 × 10 ⁻⁵ Torr or less, 630 ° C. × 3
After heating under the condition of 0 minutes, the solution was cooled at a temperature decreasing rate of 2 ° C./min. Next, a 300 μm thick nickel-plated copper plate having a thickness of 10 μm was directly placed on the aluminum foil surface of the aluminum foil-aluminum nitride substrate joined body, and was placed at 625 ° C. under a vacuum of 1 × 10 ⁻⁵ Torr or less. 10
Minutes and joined.

A UV-curable etching resist is applied on the metal plate of the obtained bonded body by screen printing, and then an etching treatment is performed using a cupric chloride solution to form an aluminum-nickel-copper metal bonded body. Unnecessary portions of copper and nickel were dissolved and removed, and the etching resist and the aluminum foil of the metal joined body were removed with a 5% sodium hydroxide solution. Since there is a residual unnecessary brazing material or a reaction product of the active metal component and aluminum nitride between the metal circuit patterns on the substrate after this etching treatment, the substrate is immersed in a 10% ammonium fluoride solution at a temperature of 60 ° C. for 10 minutes to be immersed. It was removed and a circuit board was manufactured.

COMPARATIVE EXAMPLE 1 90 parts of silver powder, 10 parts of copper powder, 3 parts of zirconium powder, 3 parts of titanium powder and 15 parts of terpineol were mixed by weight, and a toluene solution of polyisobutyl methacrylate was added and kneaded. A brazing material paste was prepared. This brazing material paste was applied to both sides of the same aluminum nitride substrate as in Example 1 in a circuit pattern by screen printing. The coating amount (after drying) at that time was 9 mg / cm ² .

Next, 56 mm × 32 m is formed on the metal circuit forming surface.
The copper circuit pattern of m × 0.3 mm, and from contacts arranged a pattern of 56 mm × 32 mm × 0.15 mm copper heat sink metal heat radiating plate forming surface, the degree of vacuum 1 × 10 ^-5 Torr
After heating at 830 ° C. for 30 minutes under the following vacuum, cooling was performed at a temperature lowering rate of 2 ° C./min to produce a circuit board in which both the metal circuit and the metal radiator plate were made of copper.

[0039] Examples 1-20, the circuit board fabricated in Reference Example 1 and the specific Comparative Examples 1, in air, after -40 ° C. × 30 minutes holding, a heat cycle to one cycle stand 25 ° C. × 10 minutes A test was performed to measure the number of cycles at which the metal circuit or the metal heat sink was peeled off.

Further, the peel strength between the metal circuit and the aluminum nitride substrate was measured.

Further, in the metal circuit (metal joint of the first metal-third metal-second metal), the alloy layers a, b and c in the bonding layer of the first metal and the third metal are formed. E
It was measured by PMA (electron beam microanalyzer). Table 2 shows the results.

[0042]

[Table 1]

[0043]

[Table 2]

The proof stress of the first metal used in Examples and Reference Examples is 11.7 MPa for aluminum (Al) and 8.3 MPa for lead (Pb). The eutectic point of the first metal and the third metal and the eutectic point of the second metal and the third metal are as follows.

(Eutectic point of first metal-third metal) Al-Cu: 548 ° C. Pb-Cu: 327 ° C. Pb-Al: 327 ° C. (eutectic point of second metal-third metal) Cu—Ti : 890 ° C Cu-Ni: 1083 ° C Cu-Zr: 880 ° C Cu-Mo: 1000 ° C or higher Cu-W: 1000 ° C or higher Al-Ti: 660 ° C

[0046]

According to the substrate of the present invention, a highly reliable substrate (circuit substrate or heat radiation substrate) having excellent heat cycle resistance.
Is provided. The substrate of the present invention is particularly suitable for power modules such as a train drive unit and an electric vehicle.

According to the substrate manufacturing method of the present invention, a highly reliable substrate (circuit substrate or heat radiation substrate) having excellent heat cycle resistance can be manufactured with high mass productivity.

According to the metal joined body of the present invention, a metal joined body having excellent heat cycle resistance and high peel strength is provided. This metal joined body can be used as a structural material in itself, in addition to being used as a metal circuit and / or a metal heat sink of a highly reliable substrate.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-105395 (JP, A) JP-A-63-38244 (JP, A) JP-A-63-177553 (JP, A) 9299 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05K 1/09 H05K 3/38 B32B 15/04

Claims (14)

(57) [Claims] 1. A substrate in which a metal circuit and / or a metal radiator is formed on a ceramic substrate, wherein the metal circuit and / or the metal radiator is formed of the following first metal
-Metal joint of third metal-second metal (however, the first metal
The combination of the same metal as the second metal is excluded. ) Wherein the first metal is bonded to the ceramic substrate, and the first metal and the third metal are a first metal-third metal-1b group
An alloy layer a containing a metal, a first metal-third metal-4 group gold
An alloy layer b containing a metal and an alloy layer c of a first metal-third metal;
A substrate characterized in that the substrate is joined through a substrate. First metal: aluminum (Al), lead (Pb), platinum (Pt)
And a metal selected from alloys containing one or more of these metal components. Second metal: copper (Cu), silver (Ag),
A metal selected from gold (Au), aluminum (Al), and an alloy containing one or more of these metal components. Third metal: a metal selected from titanium (Ti), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), and an alloy containing one or more of these metal components. 2. The substrate according to claim 1, wherein the first metal is aluminum and the second metal is copper coated with nickel. 3. An alloy layer a having a thickness of 1 to 5 μm and an alloy layer b having a thickness of 1 to 5 μm.
Is 3 to 7 μm, and the thickness of the alloy layer c is 4 to 10 μm.
The substrate according to claim 1, wherein the substrate is provided. 4. The first metal is aluminum, the second metal is copper, the third metal is nickel , the 1b group metal is copper, and the 4b group metal.
2. The substrate according to claim 1, wherein the substrate is silicon . Substrate according to claim 1, wherein the substrate is characterized in that it is a power module substrate. 6. A metal circuit pattern and / or a metal radiator plate pattern made of a first metal is bonded to a metal circuit and / or metal radiator plate formation surface of a ceramic substrate by an active metal brazing method. A pattern of a second metal different from the first metal species through the third metal
The method for manufacturing a substrate according to claim 1, wherein the bonding is performed. 7. A solid metal plate made of a first metal is joined to a surface of a ceramic substrate on which a metal circuit is formed and / or a surface on which a metal radiator plate is formed by an active metal brazing method. The method for manufacturing a substrate according to claim 1, wherein a solid metal plate made of a different second metal is joined via a third metal, and then a metal circuit and / or a metal radiator plate is formed by etching. 8. A first metal is aluminum, wherein the second metal is characterized in that it is a copper is nickel-coated
Item 8. The method for manufacturing a substrate according to Item 6 or 7 . 9. An alloy layer a having a thickness of 1 to 5 μm and an alloy layer b
Is 3 to 7 μm, and the thickness of the alloy layer c is 4 to 10 μm.
8. The method of manufacturing a substrate according to claim 6, wherein:
Law. 10. The method according to claim 6 , wherein the substrate is a power module substrate. 11. The following first metal-third metal-second metal
Metal joined body (however, the first metal and the second metal are
Excludes combinations. ) Wherein the first metal and the third metal are an alloy layer a containing a first metal-third metal-1b group metal
And an alloy layer b containing a first metal-third metal-4 group metal
And a first metal-third metal alloy layer c. First metal: a metal selected from aluminum (Al), lead (Pb), platinum (Pt), and an alloy containing one or more of these metal components. Second metal: copper (Cu), silver (Ag), gold (A
u), aluminum (Al) and one of these metal components.
A metal selected from a species or an alloy containing two or more species. Third metal: a metal selected from titanium (Ti), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), and an alloy containing one or more of these metal components. 12. The method according to claim 12, wherein the first metal is aluminum and the second metal is aluminum.
Copper, third metal is nickel, Group 1b metal is copper, Group 4b metal
Metal bonded body according to claim 1 1, wherein the but is silicon. 13. The alloy layer a having a thickness of 1 to 5 μm,
b has a thickness of 3 to 7 μm, and alloy layer c has a thickness of 4 to 10 μm
The metal joined body according to claim 11, wherein 14. The metal joint according to claim 11, which is used for a metal circuit and / or a metal radiator of a power module substrate.
Metal bonded body of.