JP6673635B2 - Method of manufacturing bonded body, method of manufacturing power module substrate with heat sink, method of manufacturing heat sink, and bonded body, power module substrate with heat sink, and heat sink - Google Patents

Description

  According to the present invention, a metal member made of copper, nickel, or silver is joined to an aluminum alloy member made of an aluminum alloy having a solidus temperature lower than a eutectic temperature of aluminum and a metal element constituting the metal member. Method for manufacturing a bonded body, a method for manufacturing a power module substrate with a heat sink including a power module substrate and a heat sink, a method for manufacturing a heat sink including a heat sink body and a metal member layer, a bonded body, and a heat sink The present invention relates to a power module substrate and a heat sink.

A semiconductor device such as an LED or a power module has a structure in which a semiconductor element is bonded on a circuit layer made of a conductive material.
A power semiconductor element for large power control used for controlling a wind power generation, an electric vehicle, a hybrid vehicle, and the like generates a large amount of heat, and therefore, as a substrate on which it is mounted, for example, AlN (aluminum nitride), Al _2. Description of the Related Art Power module substrates including a ceramic substrate made of ₂ O ₃ (alumina) and a circuit layer formed by bonding a metal plate having excellent conductivity to one surface of the ceramic substrate have been widely used. Used. As a power joule substrate, a ceramic substrate having a metal layer formed on the other surface thereof is also provided.

For example, in a power module disclosed in Patent Document 1, a power module substrate in which a circuit layer and a metal layer made of Al are formed on one surface and the other surface of a ceramic substrate, and a solder material is interposed on the circuit layer. And a semiconductor element joined by bonding.
Then, a heat sink is joined to the metal layer side of the power module substrate, and heat transmitted from the semiconductor element to the power module substrate side is radiated to the outside via the heat sink.

By the way, when the circuit layer and the metal layer are made of Al as in the power module described in Patent Document 1, an Al oxide film is formed on the surface, so that the semiconductor element and the heat sink are joined by a solder material. Can not do it.
Therefore, conventionally, as disclosed in Patent Document 2, for example, after a Ni plating film is formed on the surfaces of the circuit layer and the metal layer by electroless plating or the like, the semiconductor element and the heat sink are soldered.
Patent Document 3 proposes a technique for joining a circuit layer and a semiconductor element, and a metal layer and a heat sink, using a silver oxide paste containing silver oxide particles and a reducing agent made of an organic substance as an alternative to a solder material. ing.

  However, as described in Patent Document 2, in a power module substrate in which a Ni plating film is formed on the surface of a circuit layer and a metal layer, the surface of the Ni plating film is oxidized in the process until the semiconductor element and the heat sink are joined. And the like, and there is a possibility that the reliability of bonding between the semiconductor element and the heat sink bonded via the solder material may be reduced. Here, if the bonding between the heat sink and the metal layer is insufficient, there is a possibility that the thermal resistance increases and the heat radiation characteristics deteriorate. In the Ni plating process, a masking process may be performed so that Ni plating is not formed in an unnecessary area and a trouble such as electrolytic corrosion does not occur. As described above, in the case of performing the plating process after performing the masking process, a large amount of labor is required in the process of forming the Ni plating film on the circuit layer surface and the metal layer surface, and the manufacturing cost of the power module is greatly increased. There was a problem that it would.

  Further, as described in Patent Literature 3, when a circuit layer and a semiconductor element and a metal layer and a heat sink are joined by using a silver oxide paste, the bonding property between Al and a fired body of the silver oxide paste is poor. In addition, it was necessary to previously form an Ag underlayer on the surface of the circuit layer and the surface of the metal layer. When the Ag underlayer is formed by plating, there is a problem that much labor is required as in the case of Ni plating.

  Thus, Patent Document 4 proposes a power module substrate in which a circuit layer and a metal layer have a laminated structure of an Al layer and a Cu layer. In this power module substrate, since the Cu layer is disposed on the surfaces of the circuit layer and the metal layer, the semiconductor element and the heat sink can be satisfactorily joined using a solder material. Therefore, the thermal resistance in the stacking direction is reduced, and the heat generated from the semiconductor element can be efficiently transmitted to the heat sink.

  Further, in Patent Document 5, one of a metal layer and a heat sink is made of aluminum or an aluminum alloy, and the other is made of copper or a copper alloy, and the metal layer and the heat sink are solid-phase diffusion bonded. A power module substrate with a heat sink has been proposed. In this power module substrate with a heat sink, the metal layer and the heat sink are solid-phase diffusion bonded, so that the heat resistance is small and the heat radiation characteristics are excellent.

Japanese Patent No. 3171234 JP-A-2004-172378 JP 2008-208442 A JP 2014-160799 A JP 2014-099596 A

Meanwhile, a heat sink having a complicated structure in which a cooling medium flow path and the like are formed inside may be manufactured using an aluminum casting alloy having a relatively low solidus temperature.
Here, when an aluminum alloy member made of an aluminum casting alloy having a low solidus temperature and a metal member made of copper or a copper alloy are subjected to solid-state diffusion bonding as described in Patent Document 5, the joining is performed. It was confirmed that many Kirkendall voids were generated near the interface. When such Kirkendall voids exist between the power module substrate and the heat sink, there is a problem that thermal resistance increases and heat radiation characteristics deteriorate.

  The present invention has been made in view of the above circumstances, and an aluminum alloy member made of an aluminum alloy having a relatively low solidus temperature and a metal member made of copper, nickel, or silver are satisfactorily joined. Patent application title: Method of joining joined body capable of producing joined body having low thermal resistance in lamination direction, method of manufacturing substrate for power module with heat sink equipped with this joined body, method of manufacturing heat sink, and joined body, power module with heat sink And a heat sink.

In order to solve the above-mentioned problem, a method for manufacturing a joined body according to the present invention provides a method of manufacturing a metal member made of copper, nickel, or silver, and having a solidus temperature of eutectic of a metal element and aluminum constituting the metal member. A method for manufacturing a joined body in which an aluminum alloy member made of an aluminum alloy at a temperature lower than a temperature is joined, wherein an aluminum having a purity of 99% by mass or more is provided between the aluminum alloy member and the metal member. An aluminum alloy member / aluminum interposed layer solid phase diffusion bonding step of solid phase diffusion bonding between the aluminum alloy member and the aluminum interposed layer; and the aluminum interposed layer and the metal member laminating the door, by holding the heated pressurized state in the stacking direction, the solid phase and the metal member and the aluminum intermediate layer An aluminum intermediate layer / metal member solid phase diffusion bonding step of diffusing bonding, and wherein the in aluminum intermediate layer / metal member solid phase diffusion bonding process, is characterized in that the heating temperature and 400 ° C. or higher.
In the present invention, the metal member is made of copper or a copper alloy, nickel or a nickel alloy, or silver or a silver alloy.

  According to the method for manufacturing a joined body having this configuration, a metal member made of copper, nickel, or silver, and an aluminum alloy whose solidus temperature is lower than the eutectic temperature of the metal element and aluminum constituting the metal member Aluminum alloy member comprising aluminum having a purity of 99% by mass or more interposed between the aluminum alloy member and the aluminum alloy member, wherein the aluminum alloy member and the aluminum intermediate layer are solid-phase diffusion-bonded to each other. Since the method includes the intervening layer solid phase diffusion bonding step and the aluminum interposed layer / metal member solid phase diffusion bonding step of solid phase diffusion bonding the aluminum interposed layer and the metal member, the aluminum alloy member and the metal member Is not directly bonded, and many Kirkendall voids are formed between the aluminum alloy member and the metal member It can be suppressed. Thereby, a joined body suitable for a heat transfer member or the like having a low thermal resistance in the laminating direction can be obtained.

In the method for manufacturing a joined body according to the present invention, there is no limitation on the order in which the aluminum alloy member / aluminum intermediate layer solid-phase diffusion bonding step and the aluminum intermediate layer / metal member solid-phase diffusion bonding step are performed. Aluminum / intermediate layer / solid phase diffusion bonding step may be followed by an aluminum / intermediate layer / metal member solid phase diffusion bonding step; A solid phase diffusion bonding step may be performed.
Alternatively, the aluminum interposed layer / metal member solid phase diffusion bonding step and the aluminum alloy member / aluminum interposed layer solid phase diffusion bonding step may be performed simultaneously. In this case, the number of manufacturing steps is reduced, and the manufacturing cost can be reduced.

The method for manufacturing a power module substrate with a heat sink according to the present invention comprises: an insulating layer; a circuit layer formed on one surface of the insulating layer; a metal layer formed on the other surface of the insulating layer; And a heat sink disposed on a surface of the layer opposite to the insulating layer, wherein a purity of 99 mass between the metal layer and the heat sink is provided between the metal layer and the heat sink. % Of aluminum is disposed, and a bonding surface of the metal layer with the aluminum interposition layer is formed of copper, nickel, or silver, and the aluminum heat treatment layer is formed of copper, nickel, or silver. Is formed of an aluminum alloy having a solidus temperature lower than the eutectic temperature of the metal element and aluminum constituting the bonding surface of the metal layer, And a heat sink / aluminum intermediate layer solid phase diffusion bonding step of solid phase diffusion bonding between the heat sink and the aluminum intermediate layer, said laminated with aluminum intermediate layer and said metal layer, held heated in a pressurized state in the stacking direction And a solid-phase diffusion bonding step of an aluminum-intercalated layer / metal layer for solid-phase diffusion bonding of the aluminum-intercalated layer and the metal layer. Is characterized in that the heating temperature is 400 ° C. or higher .

  According to the method of manufacturing a power module substrate with a heat sink having this configuration, an aluminum interposed layer made of aluminum having a purity of 99% by mass or more is interposed between the metal layer and the heat sink. A heat sink / aluminum interposed layer solid phase diffusion bonding step of solid phase diffusion bonding with the aluminum interposed layer; an aluminum interposed layer / metal layer solid phase diffusion bonding step of solid phase diffusion bonding of the aluminum interposed layer and the metal layer; Therefore, the heat sink and the metal layer are not directly joined to each other, and the generation of a large number of Kirkendall voids between the heat sink and the metal layer can be suppressed. Therefore, it is possible to manufacture a power module substrate with a heat sink having a low thermal resistance in the stacking direction and excellent heat radiation characteristics.

In the method for manufacturing a power module substrate with a heat sink according to the present invention, there is no limitation on the order of execution of the heat sink / intermediate layer solid phase diffusion bonding step and the aluminum intermediate layer / metal layer solid phase diffusion bonding step. The aluminum / metal intermediate layer solid phase diffusion bonding step may be followed by the aluminum / metal layer solid phase diffusion bonding step, or the aluminum / intermediate layer / metal layer solid phase diffusion bonding step may be followed by a heat sink / aluminum intermediate layer solid phase bonding step. A phase diffusion bonding step may be performed.
Alternatively, the heat sink / intermediate aluminum layer solid phase diffusion bonding step and the aluminum intervening layer / metal layer solid phase diffusion bonding step may be performed simultaneously. In this case, the number of manufacturing steps is reduced, the manufacturing cost can be reduced, and the thermal load on the insulating layer can be suppressed.

The method for manufacturing a heat sink according to the present invention is a method for manufacturing a heat sink including a heat sink body and a metal member layer, wherein the heat sink body and the metal member layer have an aluminum purity of 99% by mass or more. An aluminum intervening layer made of copper, nickel, or silver is provided, and the heat sink main body has a solidus temperature of a metal element and aluminum which constitute the metal member layer. A heat sink body / aluminum intervening layer solid phase diffusion bonding step of solid phase diffusion bonding between the heat sink body and the aluminum intervening layer, which is made of an aluminum alloy having a temperature lower than a eutectic temperature; by the member layer are stacked, held by heating at pressurized state in a stacking direction, and the aluminum intermediate layer And a serial metal member layer and the aluminum intermediate layer / metal member layer solid phase diffusion bonding step of solid phase diffusion bonding, comprises a, in the aluminum intermediate layer / metal member layer solid phase diffusion bonding step, the heating temperature 400 It is characterized by a temperature of at least ° C.

  According to the method for manufacturing a heat sink having this configuration, an aluminum interposed layer made of aluminum having a purity of 99% by mass or more is interposed between the metal member layer and the heat sink main body. A heat sink body / aluminum intervening layer solid phase diffusion bonding step of solid-phase diffusion bonding, and an aluminum interposing layer / metal member layer solid phase diffusion bonding step of solid-phase diffusion bonding of the aluminum interposition layer and the metal member layer. Since it is provided, the heat sink body and the metal member layer are not directly joined, and it is possible to suppress the generation of a large number of Kirkendall voids between the heat sink member and the metal member layer. Therefore, it is possible to manufacture a heat sink having low heat resistance in the stacking direction and excellent heat radiation characteristics.

In the method for manufacturing a heat sink according to the present invention, there is no limitation on the order of performing the heat sink body / aluminum interposed layer solid phase diffusion bonding step and the aluminum interposed layer / metal member layer solid phase diffusion bonding step. The aluminum intermediate layer / metal member layer solid phase diffusion bonding step may be performed after the intermediate layer solid phase diffusion bonding step, or the heat sink body / the aluminum intermediate layer solid state may be performed after the aluminum intermediate layer / metal member layer solid phase diffusion bonding step. A phase diffusion bonding step may be performed.
Alternatively, the heat sink body / aluminum interposed layer solid phase diffusion bonding step and the aluminum interposed layer / metal member layer solid phase diffusion bonding step may be performed simultaneously. In this case, the number of manufacturing steps is reduced, and the manufacturing cost can be reduced.

The joined body of the present invention is a metal member made of copper, nickel, or silver, and an aluminum alloy member made of an aluminum alloy having a solidus temperature lower than a eutectic temperature of a metal element and aluminum constituting the metal member. And an aluminum interposed layer made of aluminum having a purity of 99% by mass or more is provided between the aluminum alloy member and the metal member. The member and the aluminum intermediate layer are solid-phase diffusion bonded, the aluminum intermediate layer and the metal member are solid-phase diffusion bonded, and an intermetallic compound layer is formed at a bonding interface between the aluminum intermediate layer and the metal member. The intermetallic compound layer has a structure in which a plurality of intermetallic compounds are stacked along a bonding interface, and has a thickness of 1 μm or more and 8 μm or less. It is characterized by being enclosed .

  According to the joined body having this configuration, a metal member made of copper, nickel, or silver, and an aluminum alloy member made of an aluminum alloy having a eutectic temperature lower than the eutectic temperature of the metal element and aluminum constituting the metal member, The aluminum alloy member and the aluminum intervening layer are joined by a solid-phase diffusion joint, and the aluminum intervening layer and the metal member are joined by a solid phase. Due to the diffusion bonding, the occurrence of Kirkendall voids between the aluminum alloy member and the metal member is suppressed, the thermal resistance is low, and it is particularly suitable as a heat transfer member.

The power module substrate with a heat sink of the present invention includes an insulating layer, a circuit layer formed on one surface of the insulating layer, a metal layer formed on the other surface of the insulating layer, A power module substrate with a heat sink, comprising: a heat sink disposed on a surface opposite to the insulating layer, wherein the metal layer and the heat sink are made of aluminum having a purity of 99% by mass or more. An aluminum interposed layer is provided, and a bonding surface of the metal layer with the aluminum interposed layer is made of copper, nickel, or silver, and a bonding surface of the heat sink with the aluminum interposed layer is fixed. The aluminum alloy having a phase line temperature lower than a eutectic temperature of aluminum and a metal element forming the bonding surface of the metal layer, the heat sink and the A solid phase diffusion bond is formed between the aluminum interposed layer and the metal layer, and an intermetallic compound layer is formed at a joint interface between the aluminum interposed layer and the metal layer. The intermetallic compound layer has a structure in which a plurality of intermetallic compounds are stacked along a bonding interface, and has a thickness of 1 μm or more and 8 μm or less .

  According to the power module substrate with a heat sink having this configuration, an aluminum interposed layer made of aluminum having a purity of 99% by mass or more is interposed between the metal layer and the heat sink, and the heat sink and the aluminum interposed layer are separated from each other. Since the solid-state diffusion bonding is performed and the aluminum intermediate layer and the metal layer are solid-phase diffusion bonded, the occurrence of Kirkendall voids between the heat sink and the metal layer is suppressed, the thermal resistance is low, and the heat radiation property is low. Especially excellent.

The heat sink according to the present invention is a heat sink including a heat sink body and a metal member layer, wherein an aluminum intervening layer made of aluminum having a purity of 99% by mass or more is provided between the heat sink body and the metal member layer. The metal member layer is made of copper, nickel, or silver, and the heat sink body has a solidus temperature lower than a eutectic temperature of a metal element and aluminum constituting the metal member layer. Wherein the heat sink body and the aluminum interposed layer are solid-phase diffusion bonded, the aluminum interposed layer and the metal member layer are solid-phase diffusion bonded, and the aluminum interposed layer and the metal member An intermetallic compound layer is formed at a bonding interface with the layer, and the intermetallic compound layer has a plurality of intermetallic compounds at the bonding interface. Is a laminated I structure, is characterized in that it is in the range of 1μm or more 8μm or less in thickness.

  According to the heat sink having this configuration, an aluminum interposed layer made of aluminum having a purity of 99% by mass or more is interposed between the heat sink main body and the metal member layer, and the heat sink main body and the aluminum interposed layer are interposed. Since the solid-phase diffusion bonding is performed and the aluminum intermediate layer and the metal member layer are solid-phase diffusion bonded, the occurrence of Kirkendall voids between the heat sink body and the metal member layer is suppressed, and the thermal resistance is reduced. Low, especially excellent in heat dissipation characteristics.

  According to the present invention, an aluminum alloy member made of an aluminum alloy having a relatively low solidus temperature and a metal member made of copper, nickel, or silver are satisfactorily joined, and a joined body having a low thermal resistance in the lamination direction is formed. It is possible to provide a bonding method of a bonded body that can be manufactured, a method of manufacturing a power module substrate with a heat sink including the bonded body, a method of manufacturing a heat sink, and a bonded body, a power module substrate with a heat sink, and a heat sink. Become.

FIG. 1 is a schematic explanatory view of a power module including a power module substrate with a heat sink according to a first embodiment of the present invention. It is a flow figure explaining the manufacturing method of the substrate for power modules with a heat sink concerning a first embodiment. It is a schematic explanatory view of the manufacturing method of the substrate for power modules with a heat sink concerning a first embodiment. It is a schematic explanatory view of a heat sink according to a second embodiment of the present invention. It is a flowchart explaining the manufacturing method of the heat sink which concerns on 2nd embodiment. It is a schematic explanatory view of the manufacturing method of the heat sink concerning a second embodiment. It is a schematic explanatory view of a power module provided with a substrate for power modules with a heat sink which is another embodiment of the present invention.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a power module 1 using a power module substrate 30 with a heat sink according to a first embodiment of the present invention.
The power module 1 includes a power module substrate 30 with a heat sink, and a semiconductor element 3 bonded to one surface (the upper surface in FIG. 1) of the power module substrate 30 with a solder layer 2 via the solder layer 2. ing.
The power module substrate 30 with a heat sink includes the power module substrate 10 and a heat sink 31 joined to the power module substrate 10.

  The power module substrate 10 includes a ceramic substrate 11 constituting an insulating layer, a circuit layer 12 disposed on one surface (the upper surface in FIG. 1) of the ceramic substrate 11, and a circuit substrate 12 disposed on the other surface of the ceramic substrate 11. And a metal layer 13 provided.

  As shown in FIG. 3, the circuit layer 12 is formed by joining an aluminum plate 22 made of aluminum or an aluminum alloy to one surface of the ceramic substrate 11. In the present embodiment, the circuit layer 12 is formed by joining a rolled plate (aluminum plate 22) of aluminum (2N aluminum) having a purity of 99% by mass or more to the ceramic substrate 11. The thickness of the aluminum plate 22 serving as the circuit layer 12 is set within a range of 0.1 mm or more and 1.0 mm or less, and is set to 0.6 mm in the present embodiment.

As shown in FIG. 1, the metal layer 13 is laminated on an Al layer 13A provided on the other surface of the ceramic substrate 11, and on the surface of the Al layer 13A opposite to the surface to which the ceramic substrate 11 is joined. Cu layer 13B.
As shown in FIG. 3, the Al layer 13A is formed by joining an aluminum plate 23A made of aluminum or an aluminum alloy to the other surface of the ceramic substrate 11. In the present embodiment, the Al layer 13 </ b> A is formed by joining a rolled plate (aluminum plate 23 </ b> A) of aluminum (2N aluminum) having a purity of 99% by mass or more to the ceramic substrate 11. The thickness of the aluminum plate 23A to be joined is set in the range of 0.1 mm or more and 1.0 mm or less, and is set to 0.6 mm in the present embodiment.
The Cu layer 13B is formed by joining a copper plate 23B made of copper or a copper alloy to the other surface of the Al layer 13A. In the present embodiment, the Cu layer 13B is formed by joining a rolled plate of oxygen-free copper (copper plate 23B). The thickness of the copper layer 13B is set in the range of 0.1 mm or more and 6 mm or less, and is set to 1 mm in the present embodiment.

  The heat sink 31 is for dissipating heat on the power module substrate 10 side. In the present embodiment, as shown in FIG. 1, a flow path 32 through which a cooling medium flows is provided. The heat sink 31 is made of an aluminum alloy whose solidus temperature is lower than the eutectic temperature (548 ° C.) of Cu and Al constituting the bonding surface (Cu layer 13B) of the metal layer 13. Is composed of ADC12 (solidus temperature 515 ° C.) which is an aluminum alloy for die casting specified in JIS H 2118: 2006. The ADC 12 is an aluminum alloy containing Cu in a range of 1.5 to 3.5% by mass and Si in a range of 9.6 to 12.0% by mass.

The aluminum intervening layer 18 is interposed between the heat sink 31 and the metal layer 13 (Cu layer 13B).
The aluminum interposed layer 18 is joined to an aluminum plate 28 made of 2N aluminum having a purity of 99% by mass or more, 3N aluminum having a purity of 99.9% by mass or more, or 4N aluminum having a purity of 99.99% by mass or more. It is configured. In the present embodiment, a 2N aluminum plate having a purity of 99% by mass or more is used as the aluminum plate 28 constituting the aluminum interposed layer 18, and the thickness is set in a range of 0.05 mm to 0.6 mm. More preferably, it is set to be 0.05 mm or more and 0.3 mm or less.
Here, the metal layer 13 (Cu layer 13B) and the aluminum interposed layer 18, and the aluminum interposed layer 18 and the heat sink 31 are respectively solid-phase diffusion bonded.

An intermetallic compound layer is formed at the bonding interface between the metal layer 13 (Cu layer 13B) and the aluminum interposed layer 18.
This intermetallic compound layer is formed by interdiffusion of Al atoms of the aluminum interposed layer 18 and Cu atoms of the Cu layer 13B. The intermetallic compound layer has a concentration gradient in which the concentration of Al atoms gradually decreases and the concentration of Cu atoms gradually increases from the aluminum intervening layer 18 toward the Cu layer 13B.
The intermetallic compound layer is composed of an intermetallic compound composed of Cu and Al. In the present embodiment, the intermetallic compound layer has a structure in which a plurality of intermetallic compounds are stacked along a bonding interface. Here, the thickness of the intermetallic compound layer is set in the range of 1 μm to 80 μm, preferably in the range of 5 μm to 80 μm.

In the present embodiment, the intermetallic compound layer has a structure in which three kinds of intermetallic compounds are stacked, and the aluminum intercalating layer 18 and the Cu intercalating layer 18 are sequentially arranged from the aluminum intercalating layer 18 side to the Cu layer 13B side. The θ phase and the η ₂ phase are laminated along the joint interface with the layer 13B, and at least one phase of the ζ ₂ phase, the δ phase, and the γ ₂ phase is laminated. At the joint interface between the inter-compound layer and the Cu layer 13B, an oxide is dispersed in a layer along the joint interface. In this embodiment, this oxide is an aluminum oxide such as alumina (Al ₂ O ₃ ). The oxide is dispersed in a state of being divided at the interface between the intermetallic compound layer and the Cu layer 13B, and there is a region where the intermetallic compound layer and the Cu layer 13B are in direct contact. In some cases, the oxide is dispersed in a layer form in at least one of the θ phase, η ₂ phase, ζ ₂ phase, δ phase, and γ ₂ phase.

Further, at the joint interface between the heat sink 31 and the aluminum interposed layer 18, the oxide is dispersed in a layered manner on each joint surface. In the present embodiment, this oxide is an aluminum oxide such as alumina (Al ₂ O ₃ ). Note that the oxide is dispersed in a state of being divided at the interface between the heat sink 31 and the aluminum interposed layer 18, and there is a region where the heat sink 31 is directly in contact with the aluminum interposed layer 18. This oxide is presumed to be caused by the oxide film formed on the surfaces of the heat sink 31 and the aluminum interposed layer 18.

  Next, a method for manufacturing the power module substrate 30 with a heat sink according to the present embodiment will be described with reference to FIGS.

(Aluminum plate laminating step S01)
First, as shown in FIG. 3, an aluminum plate 22 serving as the circuit layer 12 is laminated on one surface of the ceramic substrate 11 with an Al-Si brazing material foil 26 interposed therebetween.
Further, on the other surface of the ceramic substrate 11, an aluminum plate 23A serving as the Al layer 13A and an Al-Si brazing material foil 26 are laminated. In this embodiment, an Al-8 mass% Si alloy foil having a thickness of 10 μm is used as the Al-Si brazing material foil 26.

(Circuit layer and Al layer forming step S02)
Then, the circuit layer 12 is formed by placing in a vacuum heating furnace and heating the aluminum plate 22 and the ceramic substrate 11 while applying pressure (pressure: 1 to 35 kgf / cm ² ) in the laminating direction. Also, the ceramic substrate 11 and the aluminum plate 23A are joined to form the Al layer 13A.
Here, the pressure in the vacuum heating furnace is set within a range from 10 ⁻⁶ Pa to 10 ⁻³ Pa, the heating temperature is set within a range from 600 ° C. to 643 ° C., and the holding time is set within a range from 30 minutes to 180 minutes. Preferably.

(Cu layer (metal layer) forming step S03)
Next, a copper plate 23B to be the Cu layer 13B is laminated on the other surface side of the Al layer 13A.

Then, the Al layer 13A and the copper plate 23B are solid-phase diffusion-bonded to each other to form a metal layer 13 while being placed in a vacuum heating furnace and heated in a state where pressure is applied in the stacking direction (pressure 3 to 35 kgf / cm ² ). .
Here, the pressure in the vacuum heating furnace is set in the range of 10 ⁻⁶ Pa to 10 ⁻³ Pa, the heating temperature is set in the range of 400 ° C. to 548 ° C., and the holding time is set in the range of 5 minutes to 240 minutes. Preferably.
The bonding surfaces of the Al layer 13A and the copper plate 23B to be subjected to solid-phase diffusion bonding are smoothed in advance by removing scratches on the surfaces.

(Aluminum interposed layer / metal layer solid phase diffusion bonding step S04 and heat sink / aluminum interposed layer solid phase diffusion bonding step S05)
Next, the metal layer 13 (Cu layer 13B), the aluminum plate 28 serving as the aluminum interposed layer 18, and the heat sink 31 are stacked, and the vacuum is applied in a state where pressure is applied in the stacking direction (pressure 5 to 35 kgf / cm ² ). The metal layer 13 (Cu layer 13B) and the intervening aluminum layer 18 (aluminum plate 28), and the intervening aluminum layer 18 (aluminum plate 28) and the heat sink 31 are solid-phase diffusion-bonded, respectively, in a heating furnace. The bonding surfaces of the metal layer 13 (Cu layer 13B), the aluminum plate 28, and the heat sink 31, which are to be subjected to solid-phase diffusion bonding, are previously smoothed by removing scratches on the surfaces.
Here, the pressure in the vacuum heating furnace is in the range of 10 ⁻⁶ Pa to 10 ⁻³ Pa, the heating temperature is in the range of 400 ° C. to 520 ° C., and the holding time is in the range of 0.5 hour to 3 hours. Preferably, it is set.
Thus, the power module substrate 30 with a heat sink according to the present embodiment is manufactured.

(Semiconductor element bonding step S06)
Next, the semiconductor element 3 is stacked on one surface (front surface) of the circuit layer 12 with a solder material interposed therebetween, and soldered in a reduction furnace.
As described above, the power module 1 according to the present embodiment is manufactured.

  According to the power module substrate 30 with a heat sink according to the present embodiment having the above-described configuration, the heat sink 31 is configured such that the solidus temperature is equal to Cu and Al forming the bonding surface (Cu layer 13B) of the metal layer 13. ADC12 (solidus temperature 515 ° C), which is an aluminum alloy for die-casting specified in JIS H 2118: 2006. Therefore, the heat sink 31 having a complicated structure having the flow path 32 can be configured, and the heat radiation performance can be improved.

  In the present embodiment, the metal layer 13 has an Al layer 13A and a Cu layer 13B, and the purity between the metal layer 13 (Cu layer 13B) and the heat sink 31 made of an aluminum alloy having a relatively low melting point. Since the aluminum interposed layer 18 made of 99% by mass or more of aluminum is interposed, and the metal layer 13 (Cu layer 13B) and the aluminum interposed layer 18 and the aluminum interposed layer 18 and the heat sink 31 are solid-phase diffusion bonded, respectively. The occurrence of Kirkendall voids at the bonding interface between the heat sink 31 and the aluminum interposed layer 18 and the bonding interface between the aluminum interposed layer 18 and the metal layer 13 (Cu13B) can be suppressed. Therefore, it becomes possible to manufacture the power module substrate 30 with a heat sink having a low thermal resistance in the laminating direction and having excellent heat radiation characteristics.

  Further, in this embodiment, since the aluminum intermediate layer / metal layer solid phase diffusion bonding step S04 and the heat sink / aluminum intermediate layer solid phase diffusion bonding step S05 are simultaneously performed, the number of manufacturing steps can be reduced. It is possible to reduce the manufacturing cost of the attached power module substrate 30.

  Further, in the solid-phase diffusion bonding, if there is a flaw in the bonding surface, a gap may be generated at the bonding interface. However, in the present embodiment, the Cu layer 13B (copper plate 23B) and the aluminum intervening layer 18 (aluminum plate) are used. 28) Since the surface of the heat sink 31 to be joined is solid-phase diffusion-bonded after the surface of the surface has been removed and smoothed in advance, it is possible to suppress the formation of a gap at each joint interface. Thus, solid phase diffusion bonding can be performed reliably.

  Further, in the present embodiment, an intermetallic compound layer composed of an intermetallic compound layer of Cu and Al is formed at a bonding interface between the metal layer 13 (Cu layer 13B) and the aluminum intervening layer 18. Since the layer has a structure in which a plurality of intermetallic compounds are stacked along the bonding interface, it is possible to suppress the brittle intermetallic compound from growing significantly. Further, the volume fluctuation inside the intermetallic compound layer is reduced, and the internal strain is suppressed.

  Furthermore, in the present embodiment, at the bonding interface between the Cu layer 13B and the intermetallic compound layer, the oxide is dispersed in a layer along each of the bonding interfaces, so that the aluminum intervening layer 18 (the aluminum plate 28) The oxide film formed on the bonding surface is surely destroyed, and the interdiffusion of Cu and Al has sufficiently proceeded, and the Cu layer 13B and the aluminum interposed layer 18 are securely bonded.

(Second embodiment)
Next, a heat sink according to a second embodiment of the present invention will be described. FIG. 4 shows a heat sink 101 according to the second embodiment of the present invention.
The heat sink 101 includes a heat sink body 110 and a metal member layer 117 made of copper, nickel, or silver laminated on one surface (upper side in FIG. 4) of the heat sink body 110. In this embodiment, as shown in FIG. 6, the metal member layer 117 is configured by joining a metal plate 127 made of a rolled plate of oxygen-free copper.

  The heat sink body 110 is provided with a flow path 111 through which a cooling medium flows. The heat sink body 110 is made of an aluminum alloy whose solidus temperature is lower than the eutectic temperature (548 ° C.) of Al with the metal element (Cu in the present embodiment) constituting the metal member layer 117, Specifically, it is composed of ADC5 (solidus temperature 535 ° C.) which is an aluminum alloy for die casting specified in JIS H 2118: 2006. The ADC 5 is an aluminum alloy containing Mg in a range of 4.1 to 8.5% by mass.

Here, an aluminum intervening layer 118 is interposed between the heat sink body 110 and the metal member layer 117.
The aluminum interposed layer 118 is joined to an aluminum plate 128 made of 2N aluminum having a purity of 99% by mass or more, 3N aluminum having a purity of 99.9% by mass or more, or 4N aluminum having a purity of 99.99% by mass or more. It is configured. In the present embodiment, 2N aluminum having a purity of 99% by mass or more is used as the aluminum plate 128 constituting the aluminum interposed layer 118, and the thickness is set in a range of 0.05 mm or more and 0.6 mm or less. More preferably, it is set to be 0.05 mm or more and 0.3 mm or less.
Here, the metal member layer 117 and the aluminum interposed layer 118, and the aluminum interposed layer 118 and the heat sink main body 110 are solid-phase diffusion bonded, respectively.

Here, an intermetallic compound layer is formed at the joint interface between the metal member layer 117 and the aluminum intervening layer 118.
This intermetallic compound layer is formed by interdiffusion of Al atoms of the aluminum interposed layer 118 and Cu atoms of the metal member layer 117. This intermetallic compound layer has a concentration gradient in which the concentration of Al atoms gradually decreases and the concentration of Cu atoms gradually increases from the aluminum intervening layer 118 toward the metal member layer 117.
The intermetallic compound layer is composed of an intermetallic compound composed of Cu and Al. In the present embodiment, the intermetallic compound layer has a structure in which a plurality of intermetallic compounds are stacked along a bonding interface. Here, the thickness of the intermetallic compound layer is set in the range of 1 μm to 80 μm, preferably in the range of 5 μm to 80 μm.

Further, in the present embodiment, the intermetallic compound layer has a structure in which three kinds of intermetallic compounds are laminated, and the aluminum intercalating layer 118 and the metal member layer 117 are sequentially arranged from the aluminum interposing layer 118 side to the metal member layer 117 side. A θ phase and an η ₂ phase are stacked along a bonding interface with the metal member layer 117, and at least one of ζ ₂ phase, δ phase and γ ₂ phase is stacked.
At the joint interface between the intermetallic compound layer and the metal member layer 117, an oxide is dispersed in a layer along the joint interface. In this embodiment, this oxide is an aluminum oxide such as alumina (Al ₂ O ₃ ). Note that the oxide is dispersed in a state of being separated at the interface between the intermetallic compound layer and the metal member layer 117, and there is a region where the intermetallic compound layer and the metal member layer 117 are in direct contact. I have. In some cases, the oxide is dispersed in a layer form in at least one of the θ phase, η ₂ phase, ζ ₂ phase, δ phase, and γ ₂ phase.

Further, at the bonding interface between the heat sink body 110 and the aluminum intervening layer 118, the oxide is dispersed in a layer form on each bonding surface. In the present embodiment, this oxide is an aluminum oxide such as alumina (Al ₂ O ₃ ). The oxide is dispersed at the interface between the heat sink body 110 and the aluminum interposed layer 118 in a state of being divided, and there is a region where the heat sink body 110 and the aluminum interposed layer 118 are in direct contact. This oxide is presumed to be caused by the oxide film formed on the surfaces of the heat sink body 110 and the aluminum intervening layer 118.

  Next, a method for manufacturing the heat sink 101 according to the present embodiment will be described with reference to FIGS.

(Sink body / Aluminum intervening layer solid phase diffusion bonding step S101)
First, as shown in FIG. 6, a heat sink main body 110 and an aluminum plate 128 serving as an aluminum intervening layer 118 are laminated and pressurized (pressure 5-35 kgf / cm ² ) in a laminating direction and placed in a vacuum heating furnace. By arranging and heating, the aluminum plate 128 and the heat sink body 110 are solid-phase diffusion bonded. The bonding surfaces of the aluminum plate 128 and the heat sink body 110 to be subjected to the solid phase diffusion bonding are smoothed in advance by removing the scratches on the surfaces.
Here, the pressure in the vacuum heating furnace is set in the range of 10 ⁻⁶ Pa to 10 ⁻³ Pa, the heating temperature is set in the range of 400 ° C. to 520 ° C., and the holding time is set in the range of 30 minutes to 240 minutes. Preferably.

(Aluminum interposed layer / metal member layer solid phase diffusion bonding step S102)
Next, as shown in FIG. 6, the aluminum interposed layer 118 and the metal plate 127 to be the metal member layer 117 are laminated, and are pressed in the laminating direction (pressure: 1 to 35 kgf / cm ² ) in a vacuum heating furnace. And heating is performed, so that the metal plate 127 and the aluminum interposed layer 118 are solid-phase diffusion bonded. The bonding surfaces of the metal plate 127 and the aluminum interposed layer 118 to be subjected to solid-phase diffusion bonding are smoothed in advance by removing scratches on the surfaces.
Here, the pressure in the vacuum heating furnace is set in the range of 10 ⁻⁶ Pa to 10 ⁻³ Pa, the heating temperature is set in the range of 400 ° C. to 548 ° C., and the holding time is set in the range of 15 minutes to 180 minutes. Preferably.
Thus, the heat sink 101 according to the present embodiment is manufactured.

  According to the heat sink 101 according to the present embodiment having the above-described configuration, the metal member layer 117 made of a rolled plate of oxygen-free copper is joined to one surface of the heat sink main body 110 to form the metal member layer 117. Since it is formed, heat can be spread in the plane direction by the metal member layer 117, and the heat radiation characteristics can be greatly improved. Further, another member and the heat sink 101 can be satisfactorily joined using solder or the like.

  Further, the heat sink body 110 is made of an aluminum alloy whose solidus temperature is lower than the eutectic temperature (548 ° C.) of the metal element constituting the metal member layer 117 and (Cu) and Al. Is composed of ADC5 (solidus temperature: 535 ° C.) which is an aluminum alloy for die casting specified in JIS H 2118: 2006, so that the heat sink body 110 having a complicated structure having a flow path and the like is required. Can be.

  In the present embodiment, an aluminum interposed layer 118 made of aluminum having a purity of 99% by mass or more is interposed between the heat sink body 110 made of an aluminum alloy having a relatively low melting point and the metal member layer 117. Since the main body 110 and the aluminum interposed layer 118 and the aluminum interposed layer 118 and the metal member layer 117 are respectively solid-phase diffusion bonded, the bonding interface between the heat sink main body 110 and the aluminum interposed layer 118 and the aluminum interposed layer 118 and the metal member layer 117 are formed. The occurrence of Kirkendall voids at the bonding interface with the metal can be suppressed. Therefore, it is possible to manufacture the heat sink 101 having low heat resistance in the stacking direction and excellent heat radiation characteristics.

  Further, in the present embodiment, the bonding interface between the metal member layer 117 and the aluminum intervening layer 118 has the same configuration as the bonding interface between the Cu layer 13B and the aluminum intervening layer 18 in the first embodiment. The same operation and effect as in the first embodiment can be obtained.

As described above, the embodiments of the present invention have been described, but the present invention is not limited thereto, and can be appropriately changed without departing from the technical idea of the present invention.
For example, in the above embodiment, the case where the Cu layer made of copper is joined as the metal member layer has been described, but instead of the Cu layer, a Ni layer made of nickel or a nickel alloy, or a silver layer or a silver alloy is used. An Ag layer may be joined.

  When a Ni layer is formed instead of the Cu layer, the solderability is improved and the reliability of joining with other members can be improved. Furthermore, when the Ni layer is formed by solid-phase diffusion bonding, the masking process performed when forming the Ni plating film by electroless plating or the like is unnecessary, so that the manufacturing cost can be reduced. In this case, it is desirable that the thickness of the Ni layer be 1 μm or more and 30 μm or less. If the thickness of the Ni layer is less than 1 μm, the effect of improving the reliability of joining with other members may be lost. If the thickness exceeds 30 μm, the Ni layer becomes a thermal resistor and can efficiently transfer heat. It may disappear. In the case where the Ni layer is formed by solid phase diffusion bonding, the bonding temperature is set at 400 ° C. or higher and 630 ° C. or lower for the solid phase diffusion bonding of the Al layer and Ni. It can be formed under similar conditions.

  When an Ag layer is formed instead of the Cu layer, for example, when joining other members using a silver oxide paste containing silver oxide particles and a reducing agent made of an organic material, the silver oxide is reduced with the reduced silver. Since the same type of metal is bonded to the Ag layer, bonding reliability can be improved. Furthermore, since an Ag layer having good thermal conductivity is formed, heat can be spread in the plane direction and can be efficiently transmitted. In this case, it is desirable that the thickness of the Ag layer be 1 μm or more and 20 μm or less. When the thickness of the Ag layer is less than 1 μm, there is a possibility that the effect of improving the bonding reliability with other members may be lost. When the thickness is more than 20 μm, the effect of improving the bonding reliability may not be observed and the cost may increase. Invite. When the Ag layer is formed by solid-phase diffusion bonding, the bonding temperature is set at 400 ° C. or more and 560 ° C. or less for the solid-phase diffusion bonding of the Al layer and Ag. It can be formed under conditions.

  Further, in the first embodiment, the metal layer 13 has been described as having the Al layer 13A and the Cu layer 13B, but is not limited to this. As shown in FIG. It may be composed of copper or a copper alloy. In the power module 201 and the power module substrate 230 with a heat sink shown in FIG. 7, a copper plate is bonded to the other surface (the lower side in FIG. 70) of the ceramic substrate 11 by a DBC method, an active metal brazing method, or the like. Alternatively, a metal layer 213 made of a copper alloy is formed. An aluminum interposed layer 18 is interposed between the metal layer 213 and the heat sink 31, and the metal layer 213 and the aluminum interposed layer 18, and the aluminum interposed layer 18 and the heat sink 31 are solid-phase diffusion bonded. In the power module substrate 210 shown in FIG. 7, the circuit layer 212 is also made of copper or a copper alloy.

  In the first embodiment, the circuit layer is described as being formed by bonding an aluminum plate having a purity of 99% by mass. However, the present invention is not limited to this, and other circuit elements such as aluminum or aluminum alloy, copper or It may be made of another metal such as a copper alloy. Further, the circuit layer may have a two-layer structure of an Al layer and a Cu layer. The same applies to the power module substrate 210 shown in FIG.

  In the first embodiment, the description has been given assuming that the aluminum interposed layer / metal layer solid phase diffusion bonding step S04 and the heat sink / aluminum interposed layer solid phase diffusion bonding step S05 are performed simultaneously, but the present invention is not limited to this. The heat sink / intermediate layer solid phase diffusion bonding step S05 may be performed after the aluminum interposed layer / metal layer solid phase diffusion bonding step S04, or the heat sink / aluminum intermediate layer solid phase diffusion bonding step may be performed. After performing S05, an aluminum intercalation layer / metal layer solid phase diffusion bonding step S04 may be performed.

In the first embodiment, the Cu layer (metal layer) forming step S03 and the aluminum interposed layer / metal layer solid phase diffusion bonding step S04 can be performed simultaneously.
Further, in the first embodiment, the Cu layer (metal layer) forming step S03, the aluminum intermediate layer / metal layer solid phase diffusion bonding step S04, and the heat sink / aluminum intermediate layer solid phase diffusion bonding step S05 can be performed simultaneously.
In these cases, it is preferable that the bonding temperature be in the range of 450 ° C. or more and 520 ° C. or less.

  Further, in the second embodiment, the description has been made assuming that the aluminum intermediate layer / metal member layer solid phase diffusion bonding step S102 is performed after the heat sink body / aluminum intermediate layer solid phase diffusion bonding step S101 is performed. However, the heat sink body / aluminum interposed layer solid phase diffusion bonding step S101 may be performed after the aluminum interposed layer / metal member layer solid phase diffusion bonding step S102 is performed. The phase diffusion bonding step S101 and the aluminum intermediate layer / metal member layer solid phase diffusion bonding step S102 may be performed simultaneously.

Hereinafter, results of confirmation experiments performed to confirm the effects of the present invention will be described.
An aluminum alloy plate (50 mm × 50 mm × thickness 5 mm) and a metal plate (40 mm × 40 mm) shown in Table 1 were prepared. Further, an aluminum interposed layer (40 mm × 40 mm × thickness 0.1 mm) made of 2N aluminum having a purity of 99% by mass was prepared.

In Examples 1 to 6 of the present invention, the metal plate and the aluminum interposed layer shown in Table 1 and the aluminum interposed layer and the aluminum alloy plate were solid-phase diffusion bonded under the conditions shown in Table 1, respectively.
In Comparative Example 1-3, the metal plate and the aluminum alloy plate were directly solid-phase diffusion-bonded without interposing an aluminum intervening layer between the metal plate and the aluminum alloy plate. Joining was performed simultaneously.

The thermal resistance in the stacking direction was measured for the joined body thus manufactured.
A heater chip (13 mm × 10 mm × 0.25 mm) was soldered to the surface of a metal plate, and an aluminum alloy plate was brazed to a cooler. Next, the heater chip was heated with a power of 100 W, and the temperature of the heater chip was measured using a thermocouple. Further, the temperature of a cooling medium (ethylene glycol: water = 9: 1) flowing through the cooler was actually measured. The value obtained by dividing the difference between the temperature of the heater chip and the temperature of the cooling medium by the electric power was defined as the thermal resistance. Note that the thermal resistance was evaluated based on the ratio of Comparative Example 1 in which the aluminum alloy plate and the copper plate were directly diffusion-bonded without the intervening aluminum layer, and set to 1 as a reference. Table 1 shows the evaluation results.

In Comparative Example 1 in which a metal plate (copper plate) and an aluminum alloy plate were directly subjected to solid phase diffusion bonding, it was confirmed that the thermal resistance was higher than those of Examples 1 to 4 of the present invention. In addition, when Comparative Example 2 using nickel as the metal plate is compared with Inventive Example 5, it is confirmed that Comparative Example 2 has a large thermal resistance. Similarly, when Comparative Example 3 using silver as the metal plate is compared with Inventive Example 6, it is confirmed that Comparative Example 3 has a large thermal resistance. This is presumed to be due to the formation of Kirkendall voids.
On the other hand, in the example of the present invention in which the aluminum interposed layer made of 2N aluminum having a purity of 99% by mass or more is interposed between the metal plate and the aluminum alloy plate, the thermal resistance is smaller than that of the comparative example. It is confirmed that. It is presumed that the formation of Kirkendall voids was suppressed by interposing the aluminum intervening layer.

10, 210 Power module substrate 11 Ceramic substrate 13, 213 Metal layer 13B Cu layer (metal member)
18 Aluminum interposed layer 31 Heat sink (aluminum alloy member)
101 heat sink 110 heat sink body (aluminum alloy member)
117 metal member layer 118 aluminum intervening layer

Claims (9)

A metal member made of copper, nickel, or silver is joined to an aluminum alloy member made of an aluminum alloy whose solidus temperature is lower than the eutectic temperature of the metal element and aluminum constituting the metal member. A method of manufacturing a joined body,
An aluminum interposed layer made of aluminum having a purity of 99% by mass or more is disposed between the aluminum alloy member and the metal member,
An aluminum alloy member / aluminum interposed layer solid phase diffusion bonding step of solid phase diffusion bonding the aluminum alloy member and the aluminum interposed layer;
An aluminum interposed layer / metal member for laminating the aluminum interposed layer and the metal member, and heating and holding the aluminum interposed layer and the metal member in a state where the aluminum interposed layer and the metal member are pressurized in the laminating direction to solid-phase diffusion bond the aluminum interposed layer and the metal member And a solid phase diffusion bonding process .
The method for manufacturing a joined body, wherein the heating temperature is set to 400 ° C. or more in the aluminum interposed layer / metal member solid phase diffusion joining step .   The method for manufacturing a joined body according to claim 1, wherein the aluminum alloy member / aluminum interposed layer solid phase diffusion bonding step and the aluminum interposed layer / metal member solid phase diffusion bonding step are simultaneously performed. An insulating layer, a circuit layer formed on one surface of the insulating layer, a metal layer formed on the other surface of the insulating layer, and a metal layer disposed on a surface of the metal layer opposite to the insulating layer. A heat sink, and a method for manufacturing a power module substrate with a heat sink, comprising:
An aluminum interposed layer made of aluminum having a purity of 99% by mass or more is provided between the metal layer and the heat sink,
A bonding surface of the metal layer with the aluminum interposed layer is made of copper, nickel, or silver,
The joining surface of the heat sink and the aluminum interposed layer is made of an aluminum alloy having a solidus temperature lower than a eutectic temperature of a metal element and aluminum constituting the joining surface of the metal layer,
A heat sink / aluminum interposed layer solid phase diffusion bonding step of solid phase diffusion bonding the heat sink and the aluminum interposed layer;
The aluminum intervening layer / metal layer, which is formed by laminating the aluminum intervening layer and the metal layer, and heating and holding the aluminum intervening layer and the metal layer in a state of being pressed in the laminating direction, thereby solid-phase diffusion-bonding the aluminum intervening layer and the metal layer And a solid phase diffusion bonding process .
The method for manufacturing a power module substrate with a heat sink , wherein the heating temperature is 400 ° C. or more in the aluminum interposed layer / metal layer solid phase diffusion bonding step .   The method for manufacturing a power module substrate with a heat sink according to claim 3, wherein the heat sink / intermediate layer solid phase diffusion bonding step and the aluminum intermediate layer / metal layer solid phase diffusion bonding step are simultaneously performed. . A method for manufacturing a heat sink including a heat sink body and a metal member layer,
An aluminum interposed layer made of aluminum having a purity of 99% by mass or more is provided between the heat sink body and the metal member layer,
The metal member layer is made of copper, nickel, or silver,
The heat sink body is made of an aluminum alloy having a solidus temperature lower than a eutectic temperature of a metal element and aluminum constituting the metal member layer,
A heat sink body / aluminum interposed layer solid phase diffusion bonding step of solid phase diffusion bonding the heat sink body and the aluminum interposed layer;
By laminating the aluminum intervening layer and the metal member layer, and heating and holding the aluminum intervening layer and the metal member layer in a state of being pressed in the laminating direction, an aluminum intervening layer for solid-phase diffusion bonding between the aluminum intervening layer and the metal member layer / Metal member layer solid phase diffusion bonding step ,
A method for manufacturing a heat sink, wherein the heating temperature is set to 400 ° C. or more in the aluminum interposed layer / metal member layer solid phase diffusion bonding step .   The method for manufacturing a heat sink according to claim 5, wherein the heat sink body / aluminum interposed layer solid phase diffusion bonding step and the aluminum interposed layer / metal member layer solid phase diffusion bonding step are simultaneously performed. A metal member made of copper, nickel, or silver is joined to an aluminum alloy member made of an aluminum alloy whose solidus temperature is lower than the eutectic temperature of the metal element and aluminum constituting the metal member. A conjugate,
An aluminum interposed layer made of aluminum having a purity of 99% by mass or more is disposed between the aluminum alloy member and the metal member,
The aluminum alloy member and the aluminum interposed layer are solid-phase diffusion bonded,
The aluminum intervening layer and the metal member are solid-phase diffusion bonded, and an intermetallic compound layer is formed at a bonding interface between the aluminum intervening layer and the metal member.
The joined body, wherein the intermetallic compound layer has a structure in which a plurality of intermetallic compounds are stacked along a joining interface, and has a thickness in a range of 1 μm or more and 8 μm or less . An insulating layer, a circuit layer formed on one surface of the insulating layer, a metal layer formed on the other surface of the insulating layer, and a metal layer disposed on a surface of the metal layer opposite to the insulating layer. A power module substrate with a heat sink, comprising:
An aluminum interposed layer made of aluminum having a purity of 99% by mass or more is provided between the metal layer and the heat sink,
A bonding surface of the metal layer with the aluminum interposed layer is made of copper, nickel, or silver,
The joining surface of the heat sink and the aluminum interposed layer is made of an aluminum alloy having a solidus temperature lower than a eutectic temperature of a metal element and aluminum constituting the joining surface of the metal layer,
The heat sink and the aluminum interposed layer are solid-phase diffusion bonded,
The aluminum intervening layer and the metal layer are solid-phase diffusion bonded, and an intermetallic compound layer is formed at a bonding interface between the aluminum intervening layer and the metal layer,
The power module substrate with a heat sink, wherein the intermetallic compound layer has a structure in which a plurality of intermetallic compounds are stacked along a bonding interface, and has a thickness in a range of 1 μm or more and 8 μm or less . A heat sink comprising a heat sink body and a metal member layer,
An aluminum interposed layer made of aluminum having a purity of 99% by mass or more is provided between the heat sink body and the metal member layer,
The metal member layer is made of copper, nickel, or silver,
The heat sink body is made of an aluminum alloy having a solidus temperature lower than a eutectic temperature of a metal element and aluminum constituting the metal member layer,
The heat sink body and the aluminum interposed layer are solid-phase diffusion bonded,
The aluminum intervening layer and the metal member layer are solid-phase diffusion bonded, and a bonding interface between the aluminum intervening layer and the metal member layer is formed with an intermetallic compound layer,
A heat sink, wherein the intermetallic compound layer has a structure in which a plurality of intermetallic compounds are stacked along a bonding interface, and has a thickness in a range of 1 μm or more and 8 μm or less .

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