WO2016167218A1 - Bonded body, substrate for power module with heat sink, heat sink, method for producing bonded body, method for producing substrate for power module with heat sink, and method for producing heat sink - Google Patents

Bonded body, substrate for power module with heat sink, heat sink, method for producing bonded body, method for producing substrate for power module with heat sink, and method for producing heat sink Download PDF

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Publication number
WO2016167218A1
WO2016167218A1 PCT/JP2016/061691 JP2016061691W WO2016167218A1 WO 2016167218 A1 WO2016167218 A1 WO 2016167218A1 JP 2016061691 W JP2016061691 W JP 2016061691W WO 2016167218 A1 WO2016167218 A1 WO 2016167218A1
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WIPO (PCT)
Prior art keywords
layer
heat sink
metal
less
aluminum alloy
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PCT/JP2016/061691
Other languages
French (fr)
Japanese (ja)
Inventor
伸幸 寺▲崎▼
長友　義幸
Original Assignee
三菱マテリアル株式会社
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Priority claimed from JP2016033201A external-priority patent/JP6696214B2/en
Application filed by 三菱マテリアル株式会社 filed Critical 三菱マテリアル株式会社
Priority to CN201680022306.4A priority Critical patent/CN107534034B/en
Priority to US15/566,817 priority patent/US10497637B2/en
Priority to KR1020177029105A priority patent/KR102422064B1/en
Priority to EP16780009.3A priority patent/EP3285292B1/en
Publication of WO2016167218A1 publication Critical patent/WO2016167218A1/en
Priority to US15/786,786 priority patent/US10497585B2/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/12—Mountings, e.g. non-detachable insulating substrates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/12—Mountings, e.g. non-detachable insulating substrates
    • H01L23/13—Mountings, e.g. non-detachable insulating substrates characterised by the shape
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/40—Mountings or securing means for detachable cooling or heating arrangements ; fixed by friction, plugs or springs
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K7/00—Constructional details common to different types of electric apparatus
    • H05K7/20—Modifications to facilitate cooling, ventilating, or heating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321—Disposition
    • H01L2224/32151—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/32221—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/32225—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation

Definitions

  • 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 constituting the metal member and aluminum.
  • a power module substrate with a heat sink including a power module substrate and a heat sink, a heat sink including a heat sink body and a metal member layer, a method for manufacturing the bonded body, and a power module substrate with a heat sink.
  • the present invention relates to a manufacturing method and a heat sink manufacturing method.
  • Semiconductor devices such as LEDs and power modules have a structure in which a semiconductor element is bonded on a circuit layer made of a conductive material.
  • Power semiconductor elements for high power control used for controlling wind power generation, electric vehicles, hybrid vehicles, and the like generate a large amount of heat. Therefore, as a substrate on which a power semiconductor element for high power control is mounted, for example, a ceramic substrate made of AlN (aluminum nitride), Al 2 O 3 (alumina), etc., and one surface of this ceramic substrate has excellent conductivity.
  • a power module substrate including a circuit layer formed by bonding metal plates has been widely used.
  • a substrate having a metal layer formed on the other surface of a ceramic substrate is also provided.
  • 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 bonded to each other.
  • a heat sink is bonded to the metal layer side of the power module substrate, and heat transferred from the semiconductor element to the power module substrate side is dissipated to the outside through the heat sink.
  • Patent Document 2 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.
  • Patent Document 3 when a circuit layer and a semiconductor element, and a metal layer and a heat sink are bonded using a silver oxide paste, the bonding property between the sintered body of Al and the silver oxide paste is poor. In addition, it is necessary to previously form an Ag underlayer on the circuit layer surface and the metal layer surface. When the Ag underlayer is formed by plating, there is a problem that much labor is required as in the case of Ni plating.
  • 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.
  • the Cu layer is disposed on the surface of the circuit layer and the metal layer, the semiconductor element and the heat sink can be favorably bonded using a solder material. For this reason, 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 side.
  • one of the metal layer and the 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, since the metal layer and the heat sink are solid phase diffusion bonded, the thermal resistance is small and the heat dissipation characteristics are excellent.
  • a heat sink having a complicated structure in which a cooling medium flow path or the like is formed may be manufactured by an aluminum casting alloy having a relatively low solidus temperature.
  • Patent Document 5 when an aluminum alloy member made of an aluminum cast alloy having a low solidus temperature and a metal member made of copper or a copper alloy are joined by solid phase diffusion bonding, It was confirmed that a lot of Kirkendall voids were generated near the interface due to imbalance of mutual diffusion. When such a Kirkendall void is present between the power module substrate and the heat sink, there is a problem in that the thermal resistance increases and the heat dissipation characteristics deteriorate.
  • the present invention has been made in view of the above-described 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 well bonded.
  • the purpose is to do.
  • a bonded body includes a metal member made of copper, nickel, or silver, and a solid-state temperature of a metal element that forms the metal member and aluminum.
  • An aluminum alloy member made of an aluminum alloy having a temperature lower than the crystallization temperature, wherein the aluminum alloy member and the metal member are solid phase diffusion bonded, and the aluminum alloy member
  • the metal member is made of copper or copper alloy, nickel or nickel alloy, or silver or silver alloy.
  • the crystal grain aspect ratio (major axis / minor axis) is 2.5 or less and the crystal grain size is 15 ⁇ m or less on the side of the interface between the aluminum alloy member and the metal member. Since a chill layer in which a certain Si phase is dispersed is formed, and the thickness of the chill layer is 50 ⁇ m, the diffusion movement of the metal element constituting the metal member is hindered by this chill layer, and the Kirkendall void Is suppressed, and the thermal resistance in the stacking direction can be lowered.
  • a power module substrate with a heat sink 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 of the metal layer opposite to the insulating layer, wherein the bonding surface of the metal layer to the heat sink is copper, nickel, or
  • the joint surface of the heat sink and the metal layer of the heat sink is composed of an aluminum alloy whose solidus temperature is lower than the eutectic temperature of the metal element and aluminum constituting the joint surface of the metal layer.
  • the heat sink and the metal layer are solid phase diffusion bonded, and the crystal grain diameter is 2.5 or less on the bonding interface side of the heat sink with the metal layer. 15 ⁇ m are in a chill layer that Si phase is dispersed is formed below, the thickness of the chilled layer is characterized by being the least 50 [mu] m.
  • the crystal grain has an aspect ratio (major axis / minor axis) of 2.5 or less and a crystal grain size of 15 ⁇ m or less on the bonding interface side with the metal layer in the heat sink.
  • a chill layer in which the Si phase is dispersed is formed, and the thickness of the chill layer is 50 ⁇ m or more. This chill layer prevents the diffusion movement of the metal elements constituting the metal layer, thereby The generation of kendall voids is suppressed, the thermal resistance is low, and the heat dissipation characteristics are particularly excellent.
  • a heat sink according to one aspect of the present invention is a heat sink including a heat sink body and the metal member layer, wherein the metal member layer is made of copper, nickel, or silver, and the heat sink body is a solid phase. It is composed of an aluminum alloy whose linear temperature is lower than the eutectic temperature of the metal element and aluminum constituting the metal member layer, and the crystal grain aspect is formed on the bonding interface side of the heat sink body with the metal member layer.
  • Si having an aspect ratio (major axis / minor axis) of crystal grains of 2.5 or less and a crystal grain diameter of 15 ⁇ m or less is formed on the bonding interface side with the metal member layer in the heat sink body.
  • a chill layer in which phases are dispersed is formed, and the thickness of the chill layer is 50 ⁇ m or more. This chill layer prevents the diffusion movement of the metal element constituting the metal member layer, and the Kirkendall void. Is suppressed, the thermal resistance is low, and the heat dissipation characteristics are particularly excellent.
  • a metal member made of copper, nickel, or silver, and a solidus temperature is set to be lower than a eutectic temperature of the metal element constituting the metal member and aluminum.
  • the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 ⁇ m or less on the joint surface side with the metal member.
  • a chill layer in which the Si phase is dispersed and the thickness of the chill layer is 80 ⁇ m or more, it is possible to suppress the metal element constituting the metal member from diffusing and moving more than necessary during solid phase diffusion bonding, Generation of Kirkendall void can be suppressed.
  • the metal element constituting the metal member is diffused into a part of the chill layer during solid phase diffusion bonding to form a diffusion bonding layer.
  • the thickness of the chill layer may be smaller than the thickness of the chill layer before bonding.
  • the aluminum alloy member and the metal member are laminated, and the aluminum alloy member and The metal member is preferably solid phase diffusion bonded.
  • the temperature rise rate can be increased, and solid phase diffusion bonding can be performed in a relatively short time. It becomes. Thereby, even when it joins in air
  • a method for manufacturing a power module substrate with a heat sink includes an insulating layer, a circuit layer formed on one surface of the insulating layer, and a metal layer formed on the other surface of the insulating layer. And a heat sink disposed on a surface of the metal layer opposite to the insulating layer, and a method for manufacturing a power module substrate with a heat sink, wherein the bonding surface of the metal layer to the heat sink is Copper, nickel, or silver, and the joining surface of the heat sink with the metal layer has a solidus temperature less than the eutectic temperature of the metal element and aluminum constituting the joining surface of the metal layer.
  • the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 ⁇ m or less on the joint surface side with the metal layer.
  • the thickness of the chilled layer of not less than 80 [mu] m, and a and the heat sink the metal layer characterized by solid-phase diffusion bonding.
  • the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 ⁇ m or less on the bonding surface side with the metal layer.
  • the chill layer having a Si phase dispersed therein is formed and the thickness of the chill layer is 80 ⁇ m or more, the metal element constituting the bonding surface of the metal layer diffuses and moves more than necessary during solid phase diffusion bonding. This can be suppressed, and the generation of Kirkendall void 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 dissipation characteristics.
  • the heat sink and the metal layer are laminated, and heated and heated while being pressed in the laminating direction. It is preferable to perform solid phase diffusion bonding with the metal layer.
  • the rate of temperature rise can be increased, and solid phase diffusion bonding can be performed in a relatively short time. . Thereby, even when bonded in the atmosphere, for example, the influence of oxidation on the bonding surface is small, and the heat sink and the metal layer can be bonded well.
  • a heat sink manufacturing method is a heat sink manufacturing method including a heat sink body and the metal member layer, wherein the metal member layer is made of copper, nickel, or silver,
  • the heat sink body is made of an aluminum alloy whose solidus temperature is lower than the eutectic temperature of the metal element and aluminum constituting the metal member layer.
  • the metal member layer and A chill layer in which a Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 ⁇ m or less is dispersed, and the thickness of the chill layer is 80 ⁇ m or more.
  • the main body and the metal member layer are solid-phase diffusion bonded.
  • the crystal grains in the heat sink body before bonding, on the bonding surface side with the metal member layer, the crystal grains have an aspect ratio of 2.5 or less and a crystal grain size of 15 ⁇ m or less. While forming a chill layer in which phases are dispersed, and the thickness of the chill layer is 80 ⁇ m or more, it is possible to prevent the metal element constituting the metal member layer from diffusing and moving more than necessary during solid phase diffusion bonding, Generation of Kirkendall void can be suppressed. Therefore, it is possible to manufacture a heat sink having low heat resistance in the stacking direction and excellent heat dissipation characteristics.
  • the heat sink body and the metal member layer are laminated, and heated and energized while being pressed in the laminating direction. It is preferable to perform solid phase diffusion bonding with the member layer.
  • the heat sink body and the metal member layer are energized and heated while being pressed in the stacking direction, so that the rate of temperature rise can be increased and solid phase diffusion bonding can be performed in a relatively short time. It becomes. Thereby, even when it joins in air
  • 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 well bonded, and a bonded body having a low thermal resistance in the stacking direction, It becomes possible to provide a power module substrate with a heat sink and a heat sink, and a manufacturing method of the bonded body, a manufacturing method of the power module substrate with a heat sink, and a manufacturing method of the heat sink.
  • FIG. 1 It is a schematic explanatory drawing of the power module provided with the board
  • FIG. 5 is a cross-sectional enlarged explanatory view of a joining surface portion of a heat sink before joining in the method for manufacturing a power module substrate with a heat sink shown in FIG. 4. It is a schematic explanatory drawing of the heat sink which concerns on 2nd embodiment of this invention.
  • FIG. 7 is a cross-sectional enlarged explanatory view of a joining interface between a heat sink body and a metal member layer of the heat sink shown in FIG. 6. It is a flowchart explaining the manufacturing method of the heat sink which concerns on 2nd embodiment. It is a schematic explanatory drawing of the manufacturing method of the heat sink which concerns on 2nd embodiment.
  • FIG. 1 the power module 1 using the board
  • 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 heat sink via a solder layer 2.
  • the power module substrate 30 with a heat sink includes a power module substrate 10 and a heat sink 31 bonded to the power module substrate 10.
  • the power module substrate 10 is disposed on the ceramic substrate 11 constituting the insulating layer, the circuit layer 12 disposed on one surface (the upper surface in FIG. 1) of the ceramic substrate 11, and the other surface of the ceramic substrate 11. And a metal layer 13 provided.
  • the ceramic substrate 11 is made of ceramics such as Si 3 N 4 (silicon nitride), AlN (aluminum nitride), and Al 2 O 3 (alumina) that are excellent in insulation and heat dissipation.
  • the ceramic member 11 is made of AlN (aluminum nitride) that is particularly excellent in heat dissipation.
  • the thickness of the ceramic substrate 11 is set within a range of 0.2 mm to 1.5 mm, for example, and is set to 0.635 mm in the present embodiment.
  • 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.
  • the circuit layer 12 is formed by joining an aluminum (2N aluminum) rolled plate (aluminum plate 22) having a purity of 99% by mass or more to the ceramic substrate 11.
  • the thickness of the aluminum plate 22 used as the circuit layer 12 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 this embodiment.
  • the metal layer 13 is laminated on the Al layer 13A disposed 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 bonded.
  • Cu layer 13B As shown in FIG. 4, the Al layer 13 ⁇ / b> A is formed by bonding an aluminum plate 23 ⁇ / b> A made of aluminum or an aluminum alloy to the other surface of the ceramic substrate 11.
  • the Al layer 13A is formed by joining an aluminum (2N aluminum) rolled plate (aluminum plate 23A) 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 within a range of 0.1 mm or more and 3.0 mm or less, and is set to 0.6 mm in this embodiment.
  • the Cu layer 13B is formed by bonding a copper plate 23B made of copper or a copper alloy to the other surface of the Al layer 13A.
  • the Cu layer 13B is formed by bonding an oxygen-free copper rolled plate (copper plate 23B).
  • the thickness of the copper layer 13B is set within a range of 0.1 mm to 6 mm, and is set to 1 mm in this embodiment.
  • the heat sink 31 is for dissipating heat on the power module substrate 10 side, and in the present embodiment, as shown in FIG. 1, a flow path 32 through which a cooling medium flows is provided.
  • This heat sink 31 is made of a cast material of an aluminum alloy whose solidus temperature is less than the eutectic temperature (548 ° C.) of Cu and Al constituting the bonding surface (Cu layer 13B) of the metal layer 13. .
  • it is made of a cast material of ADC12 (solidus temperature 515 ° C.) which is an aluminum alloy for die casting containing Si specified in JIS H 2118: 2006.
  • the ADC 12 is an aluminum alloy containing Cu in a range of 1.5 mass% to 3.5 mass% and Si in a range of 9.6 mass% to 12.0 mass%.
  • the Si content in the cast aluminum alloy is preferably 1% by mass to 25% by mass, but is not limited thereto.
  • the heat sink 31 has a crystal grain aspect ratio (major axis / minor axis) of 2.5 or less and a crystal grain size of 15 ⁇ m or less on the side of the joint interface with the metal layer 13 (Cu layer 13B).
  • a chill layer 35 in which the Si phase is dispersed is formed.
  • the aspect ratio (major axis / minor axis) of the crystal grains of the Si phase is preferably 1.0 or more and 2.0 or less, more preferably 1.0 or more and 1.5, and the crystal grain size is preferably 0.00. Although it is 5 micrometers or more and 10 micrometers or less, More preferably, they are 1 micrometer or more and 7 micrometers or less, However It is not limited to this.
  • the chill layer 35 is formed on a surface layer portion (a portion in the vicinity of the mold) of the cast material when the cast material constituting the heat sink 31 is formed. Compared with the inside of the cast material, the chill layer 35 has a crystal grain size. It is fine and has a small aspect ratio. And the thickness (thickness of the chill layer after joining) of the chill layer 35 of the power module substrate 30 with a heat sink is 50 ⁇ m or more. The thickness of the chill layer 35 is preferably 100 ⁇ m or more, more preferably 200 ⁇ m or more, but is not limited thereto.
  • the heat sink 31 and the metal layer 13 are solid phase diffusion bonded.
  • an intermetallic compound layer 38 is formed at the bonding interface between the metal layer 13 (Cu layer 13 ⁇ / b> B) and the heat sink 31. That is, the intermetallic compound layer 38 is laminated on the chill layer 35 of the heat sink 31.
  • the intermetallic compound layer 38 is formed by mutual diffusion of Al atoms of the heat sink 31 and Cu atoms of the Cu layer 13B.
  • This intermetallic compound layer 38 has a concentration gradient in which the concentration of Al atoms gradually decreases and the concentration of Cu atoms increases as it goes from the heat sink 31 to the Cu layer 13B.
  • the intermetallic compound layer 38 is composed of an intermetallic compound composed of Cu and Al.
  • the intermetallic compound layer 38 has a structure in which a plurality of intermetallic compounds are stacked along the bonding interface.
  • the thickness of the intermetallic compound layer 38 is set in the range of 1 ⁇ m to 80 ⁇ m, preferably in the range of 5 ⁇ m to 80 ⁇ m.
  • the intermetallic compound layer 38 is formed by diffusing Cu of the Cu layer 13B toward the heat sink 31 (chill layer 35), and the intermetallic compound layer 38 includes Si contained in the heat sink 31. The particles are dispersed.
  • the intermetallic compound layer 38 has a structure in which three kinds of intermetallic compounds are laminated, and the heat sink 31 and the Cu layer 13B are joined in order from the heat sink 31 side to the Cu layer 13B side.
  • a ⁇ phase and a ⁇ 2 phase are stacked along the interface, and at least one of a ⁇ 2 phase, a ⁇ phase, and a ⁇ 2 phase is stacked.
  • oxides are dispersed in layers along the bonding interface at the bonding interface between the intermetallic compound layer and the Cu layer 13B.
  • 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.
  • the oxide is dispersed in layers within at least one of the ⁇ phase, ⁇ 2 phase, or ⁇ 2 phase, ⁇ phase, and ⁇ 2 phase.
  • an aluminum plate 22 to be 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, an aluminum plate 23A to be the Al layer 13A is laminated on the other surface of the ceramic substrate 11 with an Al—Si based brazing material foil 26 interposed therebetween. In this embodiment, an Al-8 mass% Si alloy foil having a thickness of 10 ⁇ m is used as the Al—Si brazing material foil 26.
  • circuit layer and Al layer forming step S02 Then, the aluminum plate 22 and the ceramic substrate 11 are joined by placing and heating in a vacuum heating furnace under pressure in the laminating direction (pressure 1 to 35 kgf / cm 2 (0.10 to 3.43 MPa)). The circuit layer 12 is formed. Further, the ceramic substrate 11 and the aluminum plate 23A are joined to form the Al layer 13A.
  • 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 to 600 ° C. to 650 ° C.
  • the holding time is set in the range of 30 minutes to 180 minutes. It is preferable.
  • a copper plate 23B to be the Cu layer 13B is laminated on the other surface side of the Al layer 13A.
  • the Al layer 13A and the copper plate 23B are solid-phase diffused by placing them in a vacuum heating furnace under pressure in the stacking direction (pressure 3 to 35 kgf / cm 2 (0.29 to 3.43 MPa)).
  • the metal layer 13 is formed by bonding.
  • the pressure in the vacuum heating furnace is set within the range of 10 ⁇ 6 Pa to 10 ⁇ 3 Pa
  • the heating temperature is set to 400 ° C. to 548 ° C.
  • the holding time is set within the range of 5 minutes to 240 minutes. It is preferable.
  • each surface of the Al layer 13A and the copper plate 23B to be solid-phase diffusion bonded is previously smoothed by removing scratches on the surfaces.
  • a heat sink 31 to be joined is prepared.
  • the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 ⁇ m or less on the side of the heat sink 31 where the metal layer 13 (Cu layer 13B) is joined.
  • the chill layer 35A is formed, and the thickness of the chill layer 35A is set to 80 ⁇ m or more.
  • the thickness of the chill layer 35A is preferably 100 ⁇ m or more, more preferably 200 ⁇ m or more, but is not limited thereto.
  • the thickness of the chill layer 35A described above can be controlled by adjusting the cooling rate of at least the vicinity of the joint surface of the heat sink 31.
  • the temperature of the mold during casting is 230 ° C. or lower, preferably 210 ° C. or lower.
  • the mold temperature during casting may be 140 ° C. or higher, and preferably 160 ° C. or higher.
  • the conditions for casting the heat sink include, for example, a press-fitting pressure of 400 kg / cm 2 to 600 kg / cm 2 , a molten metal temperature of 650 ° C. to 750 ° C., a gate speed of 30 m / s to 60 m / s, and a sleeve filling rate of 40% to 60 %.
  • the atmosphere may be an inert atmosphere such as nitrogen or argon, an oxygen atmosphere, a vacuum atmosphere, or the like.
  • the thickness of the chill layer 35A can be controlled by adjusting the grinding amount of the surface after casting.
  • Metal layer / heat sink bonding step S05 Next, the metal layer 13 (Cu layer 13B) and the heat sink 31 are stacked and pressurized in the stacking direction (pressure 5 to 35 kgf / cm 2 (0.49 to 3.43 MPa)) in a vacuum heating furnace.
  • the metal layer 13 (Cu layer 13B) and the heat sink 31 are solid-phase diffusion bonded by arranging and heating.
  • each joining surface of the metal layer 13 (Cu layer 13 ⁇ / b> B) and the heat sink 31 to be solid phase diffusion bonded is previously smoothed by removing scratches on the surfaces.
  • the pressure during the pressurization is more preferably 8 to 20 kgf / cm 2 (0.78 to 1.96 MPa), but is not limited thereto.
  • the pressure in the vacuum heating furnace is in the range of 10 ⁇ 6 Pa to 10 ⁇ 3 Pa
  • the heating temperature is 400 ° C. to 520 ° C.
  • the holding time is in the range of 0.25 hour to 3 hours.
  • the pressure in the vacuum heating furnace is set in the range of 10 ⁇ 5 Pa to 10 ⁇ 4 Pa
  • the heating temperature is set to 480 ° C. to 510 ° C.
  • the holding time is set in the range of 0.5 hours to 2 hours.
  • Cu atoms in the Cu layer 13B diffuse to the chill layer 35A side of the heat sink 31, and as shown in FIG. 2, an intermetallic compound layer 38 and a chill layer 35 are formed. The In this way, the power module substrate with heat sink 30 according to the present embodiment is manufactured.
  • semiconductor element bonding step S06 Next, the semiconductor element 3 is laminated on one surface (surface (upper side in FIG. 1)) of the circuit layer 12 via the solder material 2 and soldered in a reduction furnace. As described above, the power module 1 according to the present embodiment is manufactured.
  • the heat sink 31 includes Cu and Al whose solidus temperature forms the bonding surface (Cu layer 13B) of the metal layer 13.
  • ADC12 solidus temperature 515 ° C.
  • the heat sink 31 having a complicated structure having the flow path 32 can be formed, and the heat dissipation performance can be improved.
  • the crystal grain aspect ratio (major axis / minor axis) is 2.5 or less and the crystal grain size is 15 ⁇ m or less on the bonding interface side of the heat sink 31 with the metal layer 13 (Cu layer 13B). Since a chill layer 35 in which a certain Si phase is dispersed is formed, and the thickness of the chill layer 35 is 50 ⁇ m or more, diffusion movement of Cu atoms in the metal layer 13 (Cu layer 13B) is caused by the chill layer 35. Can be prevented, and the generation of Kirkendall void can be suppressed. Therefore, even when the power module substrate with heat sink 30 is held at a high temperature, the thermal resistance in the stacking direction does not increase, and deterioration of the heat dissipation characteristics can be suppressed.
  • an intermetallic compound layer 38 made of an intermetallic compound layer of Cu and Al is formed at the bonding interface between the metal layer 13 (Cu layer 13B) and the heat sink 31. Since the intermetallic compound layer 38 has a structure in which a plurality of intermetallic compounds are laminated along the bonding interface, the brittle intermetallic compound can be prevented from growing greatly. Further, the volume variation inside the intermetallic compound layer 38 is reduced, and internal strain is suppressed. Further, in the present embodiment, at the bonding interface between the Cu layer 13 ⁇ / b> B and the intermetallic compound layer 38, oxides are dispersed in layers along these bonding interfaces, so that they are formed on the bonding surface of the heat sink 31. Thus, the oxide film is surely broken, and the mutual diffusion of Cu and Al is sufficiently advanced, so that the Cu layer 13B and the heat sink 31 are reliably bonded.
  • the bonding to be bonded to the metal layer 13 (Cu layer 13B) in the heat sink 31 in the heat sink preparation step S04, as the heat sink 31 before bonding, the bonding to be bonded to the metal layer 13 (Cu layer 13B) in the heat sink 31.
  • the metal layer / heat sink bonding step S05 when the heat sink 31 and the metal layer 13 (Cu layer 13B) are solid phase diffusion bonded, Cu atoms in the Cu layer 13B diffuse and move more than necessary. This can be suppressed, and the generation of Kirkendall void can be suppressed. Therefore, it is possible to manufacture the power module substrate 30 with a heat sink having a low thermal resistance in the stacking direction and excellent heat dissipation characteristics.
  • the upper limit of the thickness of the chill layer is not particularly limited, but when the heat sink 31 made of a cast material is used, it is preferably set to 5000 ⁇ m or less. When the heat sink 31 is manufactured by casting, it is difficult to manufacture the heat sink 31 so that the thickness of the chill layer exceeds 5000 ⁇ m. When the heat sink 31 is thin, the entire heat sink 31 may be a chill layer. Even in this case, it is possible to achieve the same effects as the present embodiment.
  • FIG. 6 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 of the heat sink body 110 (upper side in FIG. 6).
  • the metal member layer 117 is configured by joining a metal plate 127 made of an oxygen-free copper rolled plate.
  • the heat sink body 110 is provided with a flow path 111 through which a cooling medium flows.
  • This heat sink body 110 is made of an aluminum alloy whose solidus temperature is less than the eutectic temperature (548 ° C.) of the metal element (Cu in this embodiment) and Al constituting the metal member layer 117, Specifically, it is made of a cast material of ADC14 (solidus temperature 507 ° C.) which is an aluminum alloy for die casting containing Si specified in JIS H 2118: 2006.
  • the ADC 14 is an aluminum alloy containing Si in a range of 16% by mass to 18% by mass and Mg in a range of 0.45% by mass to 0.65% by mass.
  • the Si content in the aluminum alloy is preferably 1% by mass to 25% by mass, but is not limited thereto.
  • the heat sink body 110 has a crystal grain aspect ratio (major axis / minor axis) of 2.5 or less and a crystal grain size of 15 ⁇ m or less.
  • a chill layer 135 in which a certain Si phase is dispersed is formed.
  • the aspect ratio (major axis / minor axis) of the crystal grains of the Si phase is preferably 1.0 or more and 2.0 or less, more preferably 1.0 or more and 1.5, and the crystal grain size is preferably 0.00. Although it is 5 micrometers or more and 10 micrometers or less, More preferably, they are 1 micrometer or more and 7 micrometers or less, However It is not limited to this.
  • the chill layer 135 is formed on a surface layer portion (a portion near the mold) of the cast material when forming the cast material constituting the heat sink body 110, and has a crystal grain size as compared with the inside of the cast material. Is fine and has a small aspect ratio.
  • the chill layer 135 has a thickness of 50 ⁇ m or more.
  • the thickness of the chill layer 135 is preferably 100 ⁇ m or more, more preferably 200 ⁇ m or more, but is not limited thereto.
  • the heat sink body 110 and the metal member layer 117 are solid phase diffusion bonded.
  • an intermetallic compound layer 138 is formed at the bonding interface between the heat sink body 110 and the metal member layer 117.
  • the intermetallic compound layer 138 is formed by mutual diffusion of Al atoms in the heat sink body 110 and Cu atoms in the metal member layer 117.
  • the intermetallic compound layer 138 has a concentration gradient in which the Al atom concentration gradually decreases and the Cu atom concentration increases as the heat sink body 110 moves toward the metal member layer 117.
  • the intermetallic compound layer 138 is composed of an intermetallic compound composed of Cu and Al.
  • the intermetallic compound layer 138 has a structure in which a plurality of intermetallic compounds are stacked along the bonding interface.
  • the thickness of the intermetallic compound layer 138 is set in the range of 1 ⁇ m to 80 ⁇ m, preferably in the range of 5 ⁇ m to 80 ⁇ m.
  • the intermetallic compound layer 138 is formed by diffusing Cu of the metal member layer 117 toward the heat sink body 110 (chill layer 135), and the intermetallic compound layer 138 includes the heat sink body 110 on the heat sink body 110.
  • the Mg particles contained may be dispersed.
  • the intermetallic compound layer 138 has a structure in which three kinds of intermetallic compounds are laminated, and the heat sink body 110 and the metal member layer are sequentially arranged from the heat sink body 110 side to the metal member layer 117 side.
  • the ⁇ phase and ⁇ 2 phase are laminated along the bonding interface with 117, and at least one of the ⁇ 2 phase, ⁇ phase, and ⁇ 2 phase is laminated.
  • the oxide is dispersed in layers along the bonding interface.
  • 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 138 and the metal member layer 117, and there is a region where the intermetallic compound layer 138 and the metal member layer 117 are in direct contact with each other. is doing. In some cases, the oxide is dispersed in layers within at least one of the ⁇ phase, the ⁇ 2 phase, or the ⁇ 2 phase, the ⁇ phase, and the ⁇ 2 phase.
  • Heat sink body preparation step S101 First, the heat sink body 110 to be joined is prepared. At this time, the crystal grain aspect ratio is 2.5 or less, similar to the heat sink 31 described in the first embodiment (see FIG. 5), on the bonding surface side of the heat sink body 110 to be bonded to the metal member layer 117.
  • the thickness of the chill layer is preferably 100 ⁇ m or more, more preferably 200 ⁇ m or more, but is not limited thereto.
  • the thickness of the chill layer can be controlled by adjusting the cooling rate at least in the vicinity of the joint surface of the heat sink body 110.
  • the temperature of the mold during casting is 230 ° C. or lower, preferably 210 ° C. or lower.
  • the mold temperature during casting may be 140 ° C. or higher, and preferably 160 ° C. or higher.
  • the conditions for casting the heat sink include, for example, a press-fitting pressure of 400 kg / cm 2 to 600 kg / cm 2 , a molten metal temperature of 650 ° C.
  • the atmosphere may be an inert atmosphere such as nitrogen or argon, an oxygen atmosphere, a vacuum atmosphere, or the like.
  • the thickness of the chill layer can be controlled by adjusting the surface grinding amount after casting.
  • the heat sink body 110 and the metal plate 127 to be the metal member layer 117 are laminated, and pressure is applied in the laminating direction (pressure 1 to 35 kgf / cm 2 (0.10 to 3.43 MPa).
  • pressure is applied in the laminating direction (pressure 1 to 35 kgf / cm 2 (0.10 to 3.43 MPa).
  • the metal plate 127 and the heat sink body 110 are solid-phase diffusion bonded by being placed in a vacuum heating furnace and heated.
  • each joining surface of the metal plate 127 and the heat sink body 110 to be solid phase diffusion bonded is previously smoothed by removing scratches on the surfaces.
  • the pressure during the pressurization is more preferably 8 to 20 kgf / cm 2 (0.78 to 1.96 MPa), but is not limited thereto.
  • the pressure in the vacuum heating furnace is in the range of 10 ⁇ 6 Pa to 10 ⁇ 3 Pa
  • the heating temperature is 400 ° C. to 520 ° C.
  • the holding time is in the range of 0.25 hour to 3 hours. It is preferably set.
  • the pressure in the vacuum heating furnace is set in the range of 10 ⁇ 5 Pa to 10 ⁇ 4 Pa
  • the heating temperature is set to 480 ° C. to 510 ° C.
  • the holding time is set in the range of 0.5 hours to 2 hours.
  • Cu atoms in the metal plate 127 diffuse toward the chill layer side of the heat sink body 110, and as shown in FIG. 7, the intermetallic compound layer 138, the chill layer 135, Is formed.
  • the heat sink 101 which is this embodiment is manufactured.
  • the metal member layer 117 is formed by joining the metal plate 127 made of an oxygen-free copper rolled plate to one surface side of the heat sink body 110. Since it is formed, heat can be spread in the surface direction by the metal member layer 117, and the heat dissipation characteristics can be greatly improved. In addition, other members and the heat sink 101 can be favorably bonded using solder or the like.
  • the heat sink body 110 is made of an aluminum alloy whose solidus temperature is less than the eutectic temperature (548 ° C.) of the metal element (Cu) and Al constituting the metal member layer 117, and specifically, Is composed of a cast material of ADC14 (solidus temperature 507 ° C), which is an aluminum alloy for die casting specified in JIS H 2118: 2006. can do.
  • the Si phase in which the aspect ratio (major axis / minor axis) of the crystal grains is 2.5 or less and the crystal grain diameter is 15 ⁇ m or less is formed on the bonding interface side with the metal member layer 117 in the heat sink body 110.
  • the thickness of the chill layer 135 is 50 ⁇ m or more, the diffusion of Cu atoms in the metal member layer 117 is prevented by the chill layer 135, Generation of Kirkendall void can be suppressed. Therefore, even when the heat sink 101 is held at a high temperature, the thermal resistance in the stacking direction does not increase, and it is possible to suppress deterioration of the heat dissipation characteristics.
  • the bonding interface between the metal member layer 117 and the heat sink body 110 has the same configuration as the bonding interface between the Cu layer 13B and the heat sink 31 in the first embodiment. It is possible to achieve the same function and effect.
  • the upper limit of the thickness of the chill layer is not particularly limited, but when the heat sink body 110 made of a cast material is used, it is preferably set to 5000 ⁇ m or less. When the heat sink body 110 is manufactured by casting, it is difficult to manufacture the heat sink body 110 so that the thickness of the chill layer exceeds 5000 ⁇ m. When the heat sink body 110 is thin, the entire heat sink body 110 may be a chill layer. Even in this case, it is possible to achieve the same effects as the present embodiment.
  • the thickness of the Ni layer is preferably 1 ⁇ m or more and 30 ⁇ m or less. If the thickness of the Ni layer is less than 1 ⁇ m, the effect of improving the reliability of bonding with other members may be lost. If the thickness exceeds 30 ⁇ m, the Ni layer becomes a thermal resistor and heat can be transferred efficiently. There is a risk of disappearing.
  • the bonding temperature is set to 400 ° C. or more and 520 ° C. or less for the solid phase diffusion bonding of the Al layer and Ni, but other conditions are the same as in the above-described embodiment. It can be formed under the following conditions.
  • the silver oxide of the silver oxide paste is reduced. Since the silver reduced by the agent and the Ag layer to be bonded are bonded between the same kind of metals, the bonding reliability can be improved. Furthermore, since an Ag layer having a good thermal conductivity is formed, heat can be spread efficiently by spreading in the surface direction.
  • the thickness of the Ag layer is preferably 1 ⁇ m or more and 20 ⁇ m or less. If the thickness of the Ag layer is less than 1 ⁇ m, the effect of improving the reliability of bonding with other members may be lost.
  • the conditions for the solid phase diffusion bonding of the Al layer and Ag are set such that the bonding temperature is 400 ° C. or more and 520 ° C. or less. It can be formed under conditions.
  • the metal layer 13 has been described as having the Al layer 13A and the Cu layer 13B.
  • the present invention is not limited to this, and as shown in FIG. Or you may comprise with a copper alloy.
  • a copper plate is joined to the other surface (lower side in FIG. 10) of the ceramic substrate 11 by the DBC method, the active metal brazing method, or the like.
  • a metal layer 213 is formed.
  • the metal layer 213 and the heat sink 31 are solid phase diffusion bonded.
  • the circuit layer 212 is also made of copper or a copper alloy.
  • a power module 201 shown in FIG. 10 includes a power module substrate 230 with a heat sink, and a semiconductor element 3 bonded to one surface (the upper surface in FIG. 10) of the power module substrate 230 with a heat sink via a solder layer 2. It is equipped with.
  • the circuit layer is described as being formed by bonding an aluminum plate having a purity of 99% by mass, but is not limited thereto, and pure aluminum having a purity of 99.99% by mass or more, It may be composed of other metals such as aluminum or aluminum alloy, copper or copper alloy.
  • 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.
  • the metal layer 13 (Cu layer 13B) and the heat sink 31 are laminated, placed in a vacuum heating furnace in a state of being pressurized in the lamination direction, and heated.
  • the heat sink main body / metal member layer joining step S102 of the second embodiment the heat sink main body 110 and the metal plate 127 to be the metal member layer 117 are stacked and pressurized in the stacking direction (pressure 5 to 35 kgf /
  • the present invention is not limited to this, and as shown in FIG.
  • an electric heating method is used. It may be.
  • an aluminum alloy member 301 and a metal member 302 are laminated, and these laminated bodies are laminated by a pair of electrodes 312 and 312 via carbon plates 311 and 311. While pressing in the direction, the aluminum alloy member 301 and the metal member 302 are energized. Then, the carbon plates 311 and 311 and the aluminum alloy member 301 and the metal member 302 are heated by Joule heat, and the aluminum alloy member 301 and the metal member 302 are solid-phase diffusion bonded.
  • the rate of temperature increase can be made relatively fast, for example, 30 to 100 ° C./min, and the solid phase can be obtained in a short time. Diffusion bonding can be performed. Thereby, the influence of the oxidation of the bonding surface is small, and for example, bonding can be performed even in an air atmosphere. Further, depending on the resistance value and specific heat of the aluminum alloy member 301 and the metal member 302, it is possible to join the aluminum alloy member 301 and the metal member 302 in a state where a temperature difference is generated, thereby reducing the difference in thermal expansion, Thermal stress can also be reduced.
  • the pressure load applied by the pair of electrodes 312 and 312 is set to be within a range of 30 kgf / cm 2 to 100 kgf / cm 2 (2.94 MPa to 9.81 MPa). preferable.
  • the pressure load is more preferably 50 kgf / cm 2 or more and 80 kgf / cm 2 or less (4.90 MPa or more and 7.85 MPa or less), but is not limited thereto.
  • the surface roughness of the aluminum alloy member 301 and the metal member 302 is 0.3 ⁇ m or more and 0.6 ⁇ m or less in terms of arithmetic average roughness Ra, or 1.
  • the surface roughness of the bonding surface is small, but in the case of the electric heating method, if the surface roughness of the bonding surface is too small, the interface contact resistance decreases, and the bonding interface Since it becomes difficult to heat locally, it is preferable to be within the above range.
  • the ceramic substrate 11 is an insulator, for example, a jig made of carbon, etc. Therefore, it is necessary to short-circuit the carbon plates 311 and 311.
  • the joining conditions are the same as the joining of the aluminum member 301 and the copper member 302 described above.
  • the surface roughness of the metal layer 13 (Cu layer 13B) and the heat sink 31 is the same as that of the aluminum member 301 and the copper member 302 described above.
  • Example 6-10 an aluminum alloy plate and a metal plate were joined by solid phase diffusion bonding by the electric heating method shown in FIG.
  • the pressure load by the electrode was 15 kgf / cm 2 (1.47 MPa)
  • the heating temperature was 510 ° C.
  • the holding time at the heating temperature was 5 min
  • the temperature rising rate was 80 ° C./min.
  • the bonding atmosphere was an air atmosphere.
  • the thickness of the chill layer formed on the joining surface side was measured as follows. First, using an EPMA (JXA-8530F manufactured by JEOL Ltd.), the surface of the aluminum plate was subjected to Si surface analysis under the conditions of a visual field of 360 ⁇ m ⁇ , an acceleration voltage of 15 kV, and an Si contour level of 0 to 1000. The Si distribution image shown in 12 (a) was obtained. The obtained Si distribution image was converted to an 8-bit gray scale to obtain a Si distribution image as shown in FIG.
  • EPMA JXA-8530F manufactured by JEOL Ltd.
  • Aspect ratio major axis / minor axis
  • Crystal grain size major axis
  • the number of particles that do not satisfy the above conditions was determined, and the number of particles that did not satisfy the conditions / conditions was determined.
  • measurement was performed every 10 ⁇ m from the surface of the aluminum plate toward the inside of the plate, the number of conditions satisfying the number / number of conditions not satisfying the condition of 3 or more was defined as the chill layer, and the thickness was determined. .
  • the evaluation results are shown in Table 1.
  • the cross-section of the joined body of the aluminum alloy plate and the metal plate bonded by solid phase diffusion was observed, and the thickness of the chill layer formed at the joint interface was measured as follows.
  • the joint interface of the joined body was observed using EPMA (JXA-8530F manufactured by JEOL Ltd.), and the intermetallic compound of Al and the metal elements (Cu, Ni, Ag) of the metal plate grown inside the aluminum alloy plate
  • the thickness of the chill layer after joining is obtained by subtracting the thickness of the intermetallic compound of Al and the metal elements (Cu, Ni, Ag) of the metal plate from the thickness of the chill layer before joining. And the thickness.
  • the thickness of the intermetallic compound was determined by line analysis of the bonding interface in the thickness direction of the bonded body.
  • the Al concentration was 65 at% to 70 at% when copper was used as the metal plate, and nickel was used as the metal plate.
  • the thickness was measured by regarding the region of 55 at% to 80 at% as the intermetallic compound when silver was used as the metal plate and the range of 20 at 45 to 45 at% as the metal plate. The evaluation results are shown in Table 1.
  • Heat cycle test Next, a heat cycle test was performed on the joined body thus manufactured.
  • TSB-51 a thermal shock tester manufactured by Espec Corp.
  • test specimen power module with heat sink
  • liquid phase Fluorinert
  • Comparative Example 1 in which an aluminum alloy plate and a metal plate (copper plate) were solid-phase diffusion bonded without forming a chill layer, it was confirmed that the thermal resistance was higher than that of the present invention. Moreover, when Comparative Example 2 using nickel as the metal plate was compared with Invention Examples 4 and 9, it was confirmed that the thermal resistance of Comparative Example 2 was increased. Similarly, when Comparative Example 3 using silver as a metal plate was compared with Invention Examples 5 and 10, it was confirmed that the thermal resistance of Comparative Example 3 was increased. These are presumed to be due to the formation of Kirkendall void.
  • the thermal resistance is smaller than that of the comparative example.
  • the thermal resistance is smaller than that of the comparative example.
  • 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 bonded, and the thermal resistance in the stacking direction It was confirmed that it is possible to obtain a bonded body having a low A.
  • 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 well bonded, and a bonded body having a low thermal resistance in the stacking direction, It becomes possible to provide a power module substrate with a heat sink and a heat sink, and a manufacturing method of the bonded body, a manufacturing method of the power module substrate with a heat sink, and a manufacturing method of the heat sink.

Abstract

This bonded body is formed by bonding a metal member comprising copper, nickel, or silver with an aluminum alloy member comprising an aluminum alloy of which the solidus temperature is less than the eutectic temperature of aluminum and the metal element that constitutes the metal member, wherein: the aluminum alloy member and metal member are bonded by solid-phase diffusion; a chill layer, in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed, is formed on the metal member bonding interface side of the aluminum alloy member; and the thickness of the chill layer is configured to be 50 μm or more.

Description

接合体、ヒートシンク付パワーモジュール用基板、ヒートシンク、及び、接合体の製造方法、ヒートシンク付パワーモジュール用基板の製造方法、ヒートシンクの製造方法Bonded body, power module substrate with heat sink, heat sink, manufacturing method of bonded body, manufacturing method of power module substrate with heat sink, manufacturing method of heat sink
　この発明は、銅、ニッケル、又は銀からなる金属部材と、固相線温度が前記金属部材を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金からなるアルミニウム合金部材とが接合されてなる接合体、パワーモジュール用基板とヒートシンクとを備えたヒートシンク付パワーモジュール用基板、ヒートシンク本体と金属部材層とを備えたヒートシンク、及び、接合体の製造方法、ヒートシンク付パワーモジュール用基板の製造方法、ヒートシンクの製造方法に関する。
　本願は、２０１５年４月１６日に、日本に出願された特願２０１５－０８４０２９号、及びに２０１６年２月２４日に、日本に出願された特願２０１６－０３３２０１号基づき優先権を主張し、その内容をここに援用する。 In this invention, 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 constituting the metal member and aluminum. A power module substrate with a heat sink including a power module substrate and a heat sink, a heat sink including a heat sink body and a metal member layer, a method for manufacturing the bonded body, and a power module substrate with a heat sink. The present invention relates to a manufacturing method and a heat sink manufacturing method.
This application claims priority based on Japanese Patent Application No. 2015-084029 filed in Japan on April 16, 2015 and Japanese Patent Application No. 2016-033201 filed on February 24, 2016 in Japan. , The contents of which are incorporated herein.
　ＬＥＤやパワーモジュール等の半導体装置においては、導電材料からなる回路層の上に半導体素子が接合された構造を備えている。
　風力発電、電気自動車、ハイブリッド自動車等を制御するために用いられる大電力制御用のパワー半導体素子においては、発熱量が多い。そのため、大電力制御用のパワー半導体素子を搭載する基板としては、例えばＡｌＮ（窒化アルミニウム）、Ａｌ２Ｏ３（アルミナ）などからなるセラミックス基板と、このセラミックス基板の一方の面に導電性の優れた金属板を接合して形成した回路層と、を備えたパワーモジュール用基板が、従来から広く用いられている。なお、パワージュール用基板としては、セラミックス基板の他方の面に金属層を形成したものも提供されている。 Semiconductor devices such as LEDs and power modules have a structure in which a semiconductor element is bonded on a circuit layer made of a conductive material.
Power semiconductor elements for high power control used for controlling wind power generation, electric vehicles, hybrid vehicles, and the like generate a large amount of heat. Therefore, as a substrate on which a power semiconductor element for high power control is mounted, for example, a ceramic substrate made of AlN (aluminum nitride), Al 2 O 3 (alumina), etc., and one surface of this ceramic substrate has excellent conductivity. Conventionally, a power module substrate including a circuit layer formed by bonding metal plates has been widely used. In addition, as a power joule substrate, a substrate having a metal layer formed on the other surface of a ceramic substrate is also provided.
　例えば、特許文献１に示すパワーモジュールにおいては、セラミックス基板の一方の面及び他方の面にＡｌからなる回路層及び金属層が形成されたパワーモジュール用基板と、この回路層上にはんだ材を介して接合された半導体素子と、を備えた構造とされている。
　パワーモジュール用基板の金属層側には、ヒートシンクが接合されており、半導体素子からパワーモジュール用基板側に伝達された熱を、ヒートシンクを介して外部へ放散する構成とされている。 For example, in the power module shown 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 bonded to each other.
A heat sink is bonded to the metal layer side of the power module substrate, and heat transferred from the semiconductor element to the power module substrate side is dissipated to the outside through the heat sink.
　ところで、特許文献１に記載されたパワーモジュールのように、回路層及び金属層をＡｌで構成した場合には、表面にＡｌの酸化皮膜が形成されるため、はんだ材によって半導体素子やヒートシンクを接合することができない。
　そこで、従来、例えば特許文献２に開示されているように、回路層及び金属層の表面に無電解めっき等によってＮｉめっき膜を形成した上で、半導体素子やヒートシンクをはんだ接合している。
　また、特許文献３には、はんだ材の代替として、酸化銀粒子と有機物からなる還元剤とを含む酸化銀ペーストを用いて、回路層と半導体素子、金属層とヒートシンクを接合する技術が提案されている。 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, since an Al oxide film is formed on the surface, the semiconductor element and the heat sink are joined by a solder material. Can not do it.
Therefore, conventionally, as disclosed in, for example, Patent Document 2, a Ni plating film is formed on the surface of a circuit layer and a metal layer by electroless plating or the like, and then a semiconductor element and a 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.
　しかしながら、特許文献２に記載されたように、回路層及び金属層表面にＮｉめっき膜を形成したパワーモジュール用基板においては、半導体素子及びヒートシンクを接合するまでの過程においてＮｉめっき膜の表面が酸化等によって劣化し、はんだ材を介して接合した半導体素子及びヒートシンクとの接合信頼性が低下するおそれがあった。ここで、ヒートシンクと金属層との接合が不十分であると、熱抵抗が上昇し、放熱特性が低下するおそれがあった。また、Ｎｉめっき工程では、不要な領域にＮｉめっきが形成されて電食等のトラブルが発生しないように、マスキング処理を行うことがある。このように、マスキング処理をした上でめっき処理をする場合、回路層表面及び金属層表面にＮｉめっき膜を形成する工程に多大な労力が必要となり、パワーモジュールの製造コストが大幅に増加してしまうといった問題があった。 However, as described in Patent Document 2, in the power module substrate in which the Ni plating film is formed on the surface of the circuit layer and the metal layer, the surface of the Ni plating film is oxidized in the process until the semiconductor element and the heat sink are joined. There is a possibility that the reliability of bonding between the semiconductor element and the heat sink bonded via the solder material may be deteriorated due to the deterioration due to the above. 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 dissipation characteristics deteriorate. Further, in the Ni plating process, masking may be performed so that Ni plating is formed in an unnecessary region and troubles such as electrolytic corrosion do not occur. As described above, when plating is performed after masking, a great amount of labor is required for the process of forming the Ni plating film on the surface of the circuit layer and the surface of the metal layer, which greatly increases the manufacturing cost of the power module. There was a problem such as.
　また、特許文献３に記載されたように、酸化銀ペーストを用いて回路層と半導体素子、金属層とヒートシンクを接合する場合には、Ａｌと酸化銀ペーストの焼成体との接合性が悪いために、予め回路層表面及び金属層表面にＡｇ下地層を形成する必要があった。Ａｇ下地層をめっきにより形成する場合には、Ｎｉめっきと同様に多大な労力が必要となるといった問題があった。 Further, as described in Patent Document 3, when a circuit layer and a semiconductor element, and a metal layer and a heat sink are bonded using a silver oxide paste, the bonding property between the sintered body of Al and the silver oxide paste is poor. In addition, it is necessary to previously form an Ag underlayer on the circuit layer surface and the metal layer surface. When the Ag underlayer is formed by plating, there is a problem that much labor is required as in the case of Ni plating.
　そこで、特許文献４には、回路層及び金属層をＡｌ層とＣｕ層の積層構造としたパワーモジュール用基板が提案されている。このパワーモジュール用基板においては、回路層及び金属層の表面にはＣｕ層が配置されるため、はんだ材を用いて半導体素子及びヒートシンクを良好に接合することができる。このため、積層方向の熱抵抗が小さくなり、半導体素子から発生した熱をヒートシンク側へと効率良く伝達することが可能となる。 Therefore, 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 surface of the circuit layer and the metal layer, the semiconductor element and the heat sink can be favorably bonded using a solder material. For this reason, 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 side.
　また、特許文献５には、金属層及びヒートシンクの一方がアルミニウム又はアルミニウム合金で構成され、他方が銅又は銅合金で構成されており、これら前記金属層と前記ヒートシンクとが固相拡散接合されたヒートシンク付パワーモジュール用基板が提案されている。このヒートシンク付パワーモジュール用基板においては、金属層とヒートシンクとが固相拡散接合されているので、熱抵抗が小さく、放熱特性に優れている。 In Patent Document 5, one of the metal layer and the 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, since the metal layer and the heat sink are solid phase diffusion bonded, the thermal resistance is small and the heat dissipation characteristics are excellent.
特許第３１７１２３４号公報Japanese Patent No. 3171234 特開２００４－１７２３７８号公報JP 2004-172378 A 特開２００８－２０８４４２号公報JP 2008-208442 A 特開２０１４－１６０７９９号公報JP 2014-160799 A 特開２０１４－０９９５９６号公報JP 2014-099596 A
　ところで、内部に冷却媒体の流路等が形成された複雑な構造のヒートシンクにおいては、比較的固相線温度が低いアルミニウム鋳物合金によって製造されることがある。
　ここで、固相線温度の低いアルミニウム鋳物合金からなるアルミニウム合金部材と、銅又は銅合金からなる金属部材とを、特許文献５に記載されたように、固相拡散接合した場合には、接合界面近傍に相互拡散の不均衡によって生じるカーケンダルボイドが多数発生することが確認された。このようなカーケンダルボイドがパワーモジュール用基板とヒートシンクとの間に存在すると、熱抵抗が上昇し、放熱特性が低下してしまうといった問題があった。 By the way, a heat sink having a complicated structure in which a cooling medium flow path or the like is formed may be manufactured by an aluminum casting alloy having a relatively low solidus temperature.
Here, as described in Patent Document 5, when an aluminum alloy member made of an aluminum cast alloy having a low solidus temperature and a metal member made of copper or a copper alloy are joined by solid phase diffusion bonding, It was confirmed that a lot of Kirkendall voids were generated near the interface due to imbalance of mutual diffusion. When such a Kirkendall void is present between the power module substrate and the heat sink, there is a problem in that the thermal resistance increases and the heat dissipation characteristics deteriorate.
　この発明は、前述した事情に鑑みてなされたものであって、比較的固相線温度の低いアルミニウム合金からなるアルミニウム合金部材と、銅、ニッケル、又は銀からなる金属部材とが良好に接合され、積層方向の熱抵抗が低い接合体、この接合体を備えたヒートシンク付パワーモジュール用基板及びヒートシンク、及び、接合体の製造方法、ヒートシンク付パワーモジュール用基板の製造方法、ヒートシンクの製造方法を提供することを目的とする。 The present invention has been made in view of the above-described 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 well bonded. , A bonded body having a low thermal resistance in the stacking direction, a power module substrate and a heat sink with a heat sink including the bonded body, a manufacturing method of the bonded body, a manufacturing method of a power module substrate with a heat sink, and a heat sink manufacturing method The purpose is to do.
　前述の課題を解決するために、本発明の一態様である接合体は、銅、ニッケル、又は銀からなる金属部材と、固相線温度が前記金属部材を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金からなるアルミニウム合金部材と、が接合されてなる接合体であって、前記アルミニウム合金部材と前記金属部材とが固相拡散接合されており、前記アルミニウム合金部材のうち前記金属部材との接合界面側には、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、前記チル層の厚さが５０μｍ以上とされていることを特徴としている。
　なお、本発明において、金属部材は、銅又は銅合金、ニッケル又はニッケル合金、もしくは銀又は銀合金で構成されている。 In order to solve the above-described problems, a bonded body according to one embodiment of the present invention includes a metal member made of copper, nickel, or silver, and a solid-state temperature of a metal element that forms the metal member and aluminum. An aluminum alloy member made of an aluminum alloy having a temperature lower than the crystallization temperature, wherein the aluminum alloy member and the metal member are solid phase diffusion bonded, and the aluminum alloy member A chill layer in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed is formed on the bonding interface side with the metal member, and the thickness of the chill layer is It is characterized by being 50 μm or more.
In the present invention, the metal member is made of copper or copper alloy, nickel or nickel alloy, or silver or silver alloy.
　この構成の接合体によれば、前記アルミニウム合金部材のうち前記金属部材との接合界面側には、結晶粒のアスペクト比（長径／短径）が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、前記チル層の厚さが５０μｍとされているので、このチル層によって金属部材を構成する金属元素の拡散移動が妨げられて、カーケンダルボイドの発生が抑制されることになり、積層方向の熱抵抗を低くすることができる。 According to the joined body of this configuration, the crystal grain aspect ratio (major axis / minor axis) is 2.5 or less and the crystal grain size is 15 μm or less on the side of the interface between the aluminum alloy member and the metal member. Since a chill layer in which a certain Si phase is dispersed is formed, and the thickness of the chill layer is 50 μm, the diffusion movement of the metal element constituting the metal member is hindered by this chill layer, and the Kirkendall void Is suppressed, and the thermal resistance in the stacking direction can be lowered.
　本発明の一態様であるヒートシンク付パワーモジュール用基板は、絶縁層と、この絶縁層の一方の面に形成された回路層と、前記絶縁層の他方の面に形成された金属層と、この金属層の前記絶縁層とは反対側の面に配置されたヒートシンクと、を備えたヒートシンク付パワーモジュール用基板であって、前記金属層のうち前記ヒートシンクとの接合面は、銅、ニッケル、又は銀で構成され、前記ヒートシンクのうち前記金属層との接合面は、固相線温度が前記金属層の前記接合面を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成され、前記ヒートシンクと前記金属層とが固相拡散接合されており、前記ヒートシンクのうち前記金属層との接合界面側には、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、前記チル層の厚さが５０μｍ以上とされていることを特徴としている。 A power module substrate with a heat sink according to one aspect 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 of the metal layer opposite to the insulating layer, wherein the bonding surface of the metal layer to the heat sink is copper, nickel, or The joint surface of the heat sink and the metal layer of the heat sink is composed of an aluminum alloy whose solidus temperature is lower than the eutectic temperature of the metal element and aluminum constituting the joint surface of the metal layer. The heat sink and the metal layer are solid phase diffusion bonded, and the crystal grain diameter is 2.5 or less on the bonding interface side of the heat sink with the metal layer. 15μm are in a chill layer that Si phase is dispersed is formed below, the thickness of the chilled layer is characterized by being the least 50 [mu] m.
　この構成のヒートシンク付パワーモジュール用基板によれば、前記ヒートシンクのうち前記金属層との接合界面側に、結晶粒のアスペクト比（長径／短径）が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、前記チル層の厚さが５０μｍ以上とされているので、このチル層によって金属層を構成する金属元素の拡散移動が妨げられて、カーケンダルボイドの発生が抑制されることになり、熱抵抗が低く、放熱特性に特に優れている。 According to the power module substrate with a heat sink having this configuration, the crystal grain has an aspect ratio (major axis / minor axis) of 2.5 or less and a crystal grain size of 15 μm or less on the bonding interface side with the metal layer in the heat sink. A chill layer in which the Si phase is dispersed is formed, and the thickness of the chill layer is 50 μm or more. This chill layer prevents the diffusion movement of the metal elements constituting the metal layer, thereby The generation of kendall voids is suppressed, the thermal resistance is low, and the heat dissipation characteristics are particularly excellent.
　本発明の一態様であるヒートシンクは、ヒートシンク本体と、前記金属部材層と、を備えたヒートシンクであって、前記金属部材層は、銅、ニッケル、又は銀からなり、前記ヒートシンク本体は、固相線温度が前記金属部材層を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成され、前記ヒートシンク本体のうち前記金属部材層との接合界面側には、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、前記チル層の厚さが５０μｍ以上とされていることを特徴としている。 A heat sink according to one aspect of the present invention is a heat sink including a heat sink body and the metal member layer, wherein the metal member layer is made of copper, nickel, or silver, and the heat sink body is a solid phase. It is composed of an aluminum alloy whose linear temperature is lower than the eutectic temperature of the metal element and aluminum constituting the metal member layer, and the crystal grain aspect is formed on the bonding interface side of the heat sink body with the metal member layer. A chill layer in which a Si phase having a ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed, and the thickness of the chill layer is 50 μm or more.
　この構成のヒートシンクによれば、前記ヒートシンク本体のうち前記金属部材層との接合界面側に、結晶粒のアスペクト比（長径／短径）が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、前記チル層の厚さが５０μｍ以上とされているので、このチル層によって金属部材層を構成する金属元素の拡散移動が妨げられて、カーケンダルボイドの発生が抑制されることになり、熱抵抗が低く、放熱特性に特に優れている。 According to the heat sink of this configuration, Si having an aspect ratio (major axis / minor axis) of crystal grains of 2.5 or less and a crystal grain diameter of 15 μm or less is formed on the bonding interface side with the metal member layer in the heat sink body. A chill layer in which phases are dispersed is formed, and the thickness of the chill layer is 50 μm or more. This chill layer prevents the diffusion movement of the metal element constituting the metal member layer, and the Kirkendall void. Is suppressed, the thermal resistance is low, and the heat dissipation characteristics are particularly excellent.
　本発明の一態様である接合体の製造方法は、銅、ニッケル、又は銀からなる金属部材と、固相線温度が前記金属部材を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金からなるアルミニウム合金部材と、が接合されてなる接合体の製造方法であって、接合前の前記アルミニウム合金部材において、前記金属部材との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上とし、このアルミニウム合金部材と前記金属部材とを固相拡散接合することを特徴としている。 In the method for manufacturing a joined body according to one aspect of the present invention, a metal member made of copper, nickel, or silver, and a solidus temperature is set to be lower than a eutectic temperature of the metal element constituting the metal member and aluminum. A method of manufacturing a joined body in which an aluminum alloy member made of an aluminum alloy is joined, wherein the aspect ratio of crystal grains is 2. on the joining surface side with the metal member in the aluminum alloy member before joining. Forming a chill layer in which a Si phase having a crystal grain size of 15 μm or less is dispersed and having a thickness of 80 μm or more, and solid-phase diffusion bonding the aluminum alloy member and the metal member It is characterized by.
　この構成の接合体の製造方法によれば、接合前の前記アルミニウム合金部材において、前記金属部材との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上としているので、固相拡散接合時に、金属部材を構成する金属元素が必要以上に拡散移動することを抑制でき、カーケンダルボイドの発生を抑制することができる。
　なお、金属部材を構成する金属元素によっては、固相拡散接合の際に、チル層の一部に金属部材を構成する金属元素が拡散して拡散接合層が形成されることから、接合後のチル層の厚さは接合前のチル層の厚さよりも薄くなることがある。 According to the method for manufacturing a joined body having this configuration, in the aluminum alloy member before joining, the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less on the joint surface side with the metal member. While forming a chill layer in which the Si phase is dispersed and the thickness of the chill layer is 80 μm or more, it is possible to suppress the metal element constituting the metal member from diffusing and moving more than necessary during solid phase diffusion bonding, Generation of Kirkendall void can be suppressed.
Depending on the metal element constituting the metal member, the metal element constituting the metal member is diffused into a part of the chill layer during solid phase diffusion bonding to form a diffusion bonding layer. The thickness of the chill layer may be smaller than the thickness of the chill layer before bonding.
　ここで、本発明の一態様である接合体の製造方法においては、前記アルミニウム合金部材と前記金属部材とを積層し、積層方向に加圧しながら通電して加熱することにより、前記アルミニウム合金部材と前記金属部材とを固相拡散接合することが好ましい。
　この場合、前記アルミニウム合金部材と前記金属部材とを積層方向に加圧しながら通電加熱しているので、昇温速度を速くすることができ、比較的短時間で固相拡散接合を行うことが可能となる。これにより、例えば大気中で接合した場合でも、接合面の酸化の影響が小さく、前記アルミニウム合金部材と前記金属部材とを良好に接合することができる。 Here, in the manufacturing method of the joined body which is one mode of the present invention, the aluminum alloy member and the metal member are laminated, and the aluminum alloy member and The metal member is preferably solid phase diffusion bonded.
In this case, since the aluminum alloy member and the metal member are energized and heated while being pressed in the laminating direction, the temperature rise rate can be increased, and solid phase diffusion bonding can be performed in a relatively short time. It becomes. Thereby, even when it joins in air | atmosphere, for example, the influence of the oxidation of a joining surface is small, and the said aluminum alloy member and the said metal member can be joined favorably.
　本発明の一態様であるヒートシンク付パワーモジュール用基板の製造方法は、絶縁層と、この絶縁層の一方の面に形成された回路層と、前記絶縁層の他方の面に形成された金属層と、この金属層の前記絶縁層とは反対側の面に配置されたヒートシンクと、を備えたヒートシンク付パワーモジュール用基板の製造方法であって、前記金属層のうち前記ヒートシンクとの接合面は、銅、ニッケル、又は銀で構成され、前記ヒートシンクのうち前記金属層との接合面は、固相線温度が前記金属層の前記接合面を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成されており、接合前の前記ヒートシンクにおいて、前記金属層との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上とし、このヒートシンクと前記金属層とを固相拡散接合することを特徴としている。 A method for manufacturing a power module substrate with a heat sink according to one aspect of the present invention includes an insulating layer, a circuit layer formed on one surface of the insulating layer, and a metal layer formed on the other surface of the insulating layer. And a heat sink disposed on a surface of the metal layer opposite to the insulating layer, and a method for manufacturing a power module substrate with a heat sink, wherein the bonding surface of the metal layer to the heat sink is Copper, nickel, or silver, and the joining surface of the heat sink with the metal layer has a solidus temperature less than the eutectic temperature of the metal element and aluminum constituting the joining surface of the metal layer. In the heat sink before joining, the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less on the joint surface side with the metal layer. With phase forms a chill layer dispersed, the thickness of the chilled layer of not less than 80 [mu] m, and a and the heat sink the metal layer characterized by solid-phase diffusion bonding.
　この構成のヒートシンク付パワーモジュール用基板の製造方法によれば、接合前の前記ヒートシンクにおいて、前記金属層との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上としているので、固相拡散接合時に、金属層の接合面を構成する金属元素が必要以上に拡散移動することを抑制でき、カーケンダルボイドの発生を抑制することができる。
　よって、積層方向における熱抵抗が低く、放熱特性に優れたヒートシンク付パワーモジュール用基板を製造することが可能となる。 According to the method for manufacturing a power module substrate with a heat sink having this configuration, in the heat sink before bonding, the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less on the bonding surface side with the metal layer. As the chill layer having a Si phase dispersed therein is formed and the thickness of the chill layer is 80 μm or more, the metal element constituting the bonding surface of the metal layer diffuses and moves more than necessary during solid phase diffusion bonding. This can be suppressed, and the generation of Kirkendall void 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 dissipation characteristics.
　ここで、本発明の一態様であるヒートシンク付パワーモジュール用基板の製造方法においては、前記ヒートシンクと前記金属層とを積層し、積層方向に加圧しながら通電して加熱することにより、前記ヒートシンクと前記金属層とを固相拡散接合することが好ましい。
　この場合、前記ヒートシンクと前記金属層とを積層方向に加圧しながら通電加熱しているので、昇温速度を速くすることができ、比較的短時間で固相拡散接合を行うことが可能となる。これにより、例えば大気中で接合した場合でも、接合面の酸化の影響が小さく、前記ヒートシンクと前記金属層とを良好に接合することができる。 Here, in the method for manufacturing a power module substrate with a heat sink according to one aspect of the present invention, the heat sink and the metal layer are laminated, and heated and heated while being pressed in the laminating direction. It is preferable to perform solid phase diffusion bonding with the metal layer.
In this case, since the heat sink is energized and heated while pressing the heat sink and the metal layer in the stacking direction, the rate of temperature rise can be increased, and solid phase diffusion bonding can be performed in a relatively short time. . Thereby, even when bonded in the atmosphere, for example, the influence of oxidation on the bonding surface is small, and the heat sink and the metal layer can be bonded well.
　本発明の一態様であるヒートシンクの製造方法は、ヒートシンク本体と、前記金属部材層と、を備えたヒートシンクの製造方法であって、前記金属部材層は、銅、ニッケル、又は銀からなり、前記ヒートシンク本体は、固相線温度が前記金属部材層を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成されており、接合前の前記ヒートシンク本体において、前記金属部材層との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上とし、このヒートシンク本体と前記金属部材層とを固相拡散接合することを特徴としている。 A heat sink manufacturing method according to an aspect of the present invention is a heat sink manufacturing method including a heat sink body and the metal member layer, wherein the metal member layer is made of copper, nickel, or silver, The heat sink body is made of an aluminum alloy whose solidus temperature is lower than the eutectic temperature of the metal element and aluminum constituting the metal member layer. In the heat sink body before joining, the metal member layer and A chill layer in which a Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed, and the thickness of the chill layer is 80 μm or more. The main body and the metal member layer are solid-phase diffusion bonded.
　この構成のヒートシンクの製造方法によれば、接合前の前記ヒートシンク本体において、前記金属部材層との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上としているので、固相拡散接合時に、金属部材層を構成する金属元素が必要以上に拡散移動することを抑制でき、カーケンダルボイドの発生を抑制することができる。
　よって、積層方向における熱抵抗が低く、放熱特性に優れたヒートシンクを製造することが可能となる。 According to the heat sink manufacturing method of this configuration, in the heat sink body before bonding, on the bonding surface side with the metal member layer, the crystal grains have an aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less. While forming a chill layer in which phases are dispersed, and the thickness of the chill layer is 80 μm or more, it is possible to prevent the metal element constituting the metal member layer from diffusing and moving more than necessary during solid phase diffusion bonding, Generation of Kirkendall void can be suppressed.
Therefore, it is possible to manufacture a heat sink having low heat resistance in the stacking direction and excellent heat dissipation characteristics.
　ここで、本発明の一態様であるヒートシンクの製造方法においては、前記ヒートシンク本体と前記金属部材層とを積層し、積層方向に加圧しながら通電して加熱することにより、前記ヒートシンク本体と前記金属部材層とを固相拡散接合することが好ましい。
　この場合、前記ヒートシンク本体と前記金属部材層とを積層方向に加圧しながら通電加熱しているので、昇温速度を速くすることができ、比較的短時間で固相拡散接合を行うことが可能となる。これにより、例えば大気中で接合した場合でも、接合面の酸化の影響が小さく、前記ヒートシンク本体と前記金属部材層とを良好に接合することができる。 Here, in the heat sink manufacturing method according to one aspect of the present invention, the heat sink body and the metal member layer are laminated, and heated and energized while being pressed in the laminating direction. It is preferable to perform solid phase diffusion bonding with the member layer.
In this case, the heat sink body and the metal member layer are energized and heated while being pressed in the stacking direction, so that the rate of temperature rise can be increased and solid phase diffusion bonding can be performed in a relatively short time. It becomes. Thereby, even when it joins in air | atmosphere, for example, the influence of the oxidation of a joining surface is small, and the said heat sink main body and the said metal member layer can be joined favorably.
　本発明によれば、比較的固相線温度の低いアルミニウム合金からなるアルミニウム合金部材と、銅、ニッケル、又は銀からなる金属部材とが良好に接合され、積層方向の熱抵抗が低い接合体、この接合体を備えたヒートシンク付パワーモジュール用基板及びヒートシンク、及び、接合体の製造方法、ヒートシンク付パワーモジュール用基板の製造方法、ヒートシンクの製造方法を提供することが可能となる。 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 well bonded, and a bonded body having a low thermal resistance in the stacking direction, It becomes possible to provide a power module substrate with a heat sink and a heat sink, and a manufacturing method of the bonded body, a manufacturing method of the power module substrate with a heat sink, and a manufacturing method of the heat sink.
本発明の第一実施形態に係るヒートシンク付パワーモジュール用基板を備えたパワーモジュールの概略説明図である。It is a schematic explanatory drawing of the power module provided with the board | substrate for power modules with a heat sink which concerns on 1st embodiment of this invention. 図１に示すヒートシンク付パワーモジュール用基板のヒートシンクと金属層（Ｃｕ層）との接合界面の断面拡大説明図である。It is a cross-sectional expansion explanatory drawing of the joining interface of the heat sink and metal layer (Cu layer) of the board | substrate for power modules with a heat sink shown in FIG. 第一実施形態に係るヒートシンク付パワーモジュール用基板の製造方法を説明するフロー図である。It is a flowchart explaining the manufacturing method of the board | substrate for power modules with a heat sink which concerns on 1st embodiment. 第一実施形態に係るヒートシンク付パワーモジュール用基板の製造方法の概略説明図である。It is a schematic explanatory drawing of the manufacturing method of the board | substrate for power modules with a heat sink which concerns on 1st embodiment. 図４に示すヒートシンク付パワーモジュール用基板の製造方法において、接合前のヒートシンクの接合面部分の断面拡大説明図である。FIG. 5 is a cross-sectional enlarged explanatory view of a joining surface portion of a heat sink before joining in the method for manufacturing a power module substrate with a heat sink shown in FIG. 4. 本発明の第二実施形態に係るヒートシンクの概略説明図である。It is a schematic explanatory drawing of the heat sink which concerns on 2nd embodiment of this invention. 図６に示すヒートシンクのヒートシンク本体と金属部材層との接合界面の断面拡大説明図である。FIG. 7 is a cross-sectional enlarged explanatory view of a joining interface between a heat sink body and a metal member layer of the heat sink shown in FIG. 6. 第二実施形態に係るヒートシンクの製造方法を説明するフロー図である。It is a flowchart explaining the manufacturing method of the heat sink which concerns on 2nd embodiment. 第二実施形態に係るヒートシンクの製造方法の概略説明図である。It is a schematic explanatory drawing of the manufacturing method of the heat sink which concerns on 2nd embodiment. 本発明の他の実施形態であるヒートシンク付パワーモジュール用基板を備えたパワーモジュールの概略説明図である。It is a schematic explanatory drawing of the power module provided with the board | substrate for power modules with a heat sink which is other embodiment of this invention. 通電加熱法によって固相拡散接合を行う状況を示す概略説明図である。It is a schematic explanatory drawing which shows the condition which performs a solid phase diffusion joining by an electrical heating method. 実施例においてＳｉ相の輪郭を抽出する手順を示す説明図である。It is explanatory drawing which shows the procedure which extracts the outline of Si phase in an Example.
（第一実施形態）
　以下に、本発明の実施形態について、添付した図面を参照して説明する。
図１に、本発明の第一実施形態であるヒートシンク付パワーモジュール用基板３０を用いたパワーモジュール１を示す。
　このパワーモジュール１は、ヒートシンク付パワーモジュール用基板３０と、このヒートシンク付パワーモジュール用基板３０の一方の面（図１において上面）にはんだ層２を介して接合された半導体素子３と、を備えている。
　ヒートシンク付パワーモジュール用基板３０は、パワーモジュール用基板１０と、パワーモジュール用基板１０に接合されたヒートシンク３１と、を備えている。 (First embodiment)
Embodiments of the present invention will be described below with reference to the accompanying drawings.
In FIG. 1, the power module 1 using the board | substrate 30 for power modules with a heat sink which is 1st embodiment of this invention is shown.
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 heat sink via a solder layer 2. ing.
The power module substrate 30 with a heat sink includes a power module substrate 10 and a heat sink 31 bonded to the power module substrate 10.
　パワーモジュール用基板１０は、絶縁層を構成するセラミックス基板１１と、このセラミックス基板１１の一方の面（図１において上面）に配設された回路層１２と、セラミックス基板１１の他方の面に配設された金属層１３と、を備えている。 The power module substrate 10 is disposed on the ceramic substrate 11 constituting the insulating layer, the circuit layer 12 disposed on one surface (the upper surface in FIG. 1) of the ceramic substrate 11, and the other surface of the ceramic substrate 11. And a metal layer 13 provided.
　セラミックス基板１１は、絶縁性および放熱性に優れたＳｉ３Ｎ４（窒化ケイ素）、ＡｌＮ（窒化アルミニウム）、Ａｌ２Ｏ３（アルミナ）等のセラミックスで構成されている。本実施形態では、セラミックス部材１１は、特に放熱性の優れたＡｌＮ（窒化アルミニウム）で構成されている。また、セラミックス基板１１の厚さは、例えば、０．２ｍｍ～１．５ｍｍの範囲内に設定されており、本実施形態では、０．６３５ｍｍに設定されている。 The ceramic substrate 11 is made of ceramics such as Si 3 N 4 (silicon nitride), AlN (aluminum nitride), and Al 2 O 3 (alumina) that are excellent in insulation and heat dissipation. In the present embodiment, the ceramic member 11 is made of AlN (aluminum nitride) that is particularly excellent in heat dissipation. Further, the thickness of the ceramic substrate 11 is set within a range of 0.2 mm to 1.5 mm, for example, and is set to 0.635 mm in the present embodiment.
　回路層１２は、図４に示すように、セラミックス基板１１の一方の面に、アルミニウム又はアルミニウム合金からなるアルミニウム板２２が接合されることにより形成されている。本実施形態においては、回路層１２は、純度が９９質量％以上のアルミニウム（２Ｎアルミニウム）の圧延板（アルミニウム板２２）がセラミックス基板１１に接合されることで形成されている。なお、回路層１２となるアルミニウム板２２の厚さは０．１ｍｍ以上１．０ｍｍ以下の範囲内に設定されており、本実施形態では、０．６ｍｍに設定されている。 As shown in FIG. 4, 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 an aluminum (2N aluminum) rolled plate (aluminum plate 22) having a purity of 99% by mass or more to the ceramic substrate 11. In addition, the thickness of the aluminum plate 22 used as the circuit layer 12 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 this embodiment.
　金属層１３は、図１に示すように、セラミックス基板１１の他方の面に配設されたＡｌ層１３Ａと、このＡｌ層１３Ａのうちセラミックス基板１１が接合された面と反対側の面に積層されたＣｕ層１３Ｂと、を有している。
　Ａｌ層１３Ａは、図４に示すように、セラミックス基板１１の他方の面に、アルミニウム又はアルミニウム合金からなるアルミニウム板２３Ａが接合されることにより形成されている。本実施形態においては、Ａｌ層１３Ａは、純度が９９質量％以上のアルミニウム（２Ｎアルミニウム）の圧延板（アルミニウム板２３Ａ）がセラミックス基板１１に接合されることで形成されている。接合されるアルミニウム板２３Ａの厚さは０．１ｍｍ以上３．０ｍｍ以下の範囲内に設定されており、本実施形態では、０．６ｍｍに設定されている。
　Ｃｕ層１３Ｂは、図４に示すように、Ａｌ層１３Ａの他方の面に、銅又は銅合金からなる銅板２３Ｂが接合されることにより形成されている。本実施形態においては、Ｃｕ層１３Ｂは、無酸素銅の圧延板（銅板２３Ｂ）が接合されることで形成されている。銅層１３Ｂの厚さは０．１ｍｍ以上６ｍｍ以下の範囲内に設定されており、本実施形態では、１ｍｍに設定されている。 As shown in FIG. 1, the metal layer 13 is laminated on the Al layer 13A disposed 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 bonded. Cu layer 13B.
As shown in FIG. 4, the Al layer 13 </ b> A is formed by bonding an aluminum plate 23 </ b> A made of aluminum or an aluminum alloy to the other surface of the ceramic substrate 11. In the present embodiment, the Al layer 13A is formed by joining an aluminum (2N aluminum) rolled plate (aluminum plate 23A) 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 within a range of 0.1 mm or more and 3.0 mm or less, and is set to 0.6 mm in this embodiment.
As shown in FIG. 4, the Cu layer 13B is formed by bonding 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 bonding an oxygen-free copper rolled plate (copper plate 23B). The thickness of the copper layer 13B is set within a range of 0.1 mm to 6 mm, and is set to 1 mm in this embodiment.
　ヒートシンク３１は、パワーモジュール用基板１０側の熱を放散するためのものであり、本実施形態では、図１に示すように、冷却媒体が流通する流路３２が設けられている。このヒートシンク３１は、固相線温度が金属層１３の接合面（Ｃｕ層１３Ｂ）を構成するＣｕとＡｌとの共晶温度（５４８℃）未満とされたアルミニウム合金の鋳造材で構成されている。具体的には、ＪＩＳ　Ｈ　２１１８：２００６で規定されたＳｉを含有するダイカスト用アルミニウム合金であるＡＤＣ１２（固相線温度５１５℃）の鋳造材で構成されている。なお、このＡＤＣ１２は、Ｃｕを１．５質量％～３．５質量％の範囲内、Ｓｉを９．６質量％～１２．０質量％の範囲内で含むアルミニウム合金である。上記アルミニウム合金の鋳造材におけるＳｉ含有量は、１質量％～２５質量％であることが好ましいが、これに限定されることはない。 The heat sink 31 is for dissipating heat on the power module substrate 10 side, and in the present embodiment, as shown in FIG. 1, a flow path 32 through which a cooling medium flows is provided. This heat sink 31 is made of a cast material of an aluminum alloy whose solidus temperature is less than the eutectic temperature (548 ° C.) of Cu and Al constituting the bonding surface (Cu layer 13B) of the metal layer 13. . Specifically, it is made of a cast material of ADC12 (solidus temperature 515 ° C.) which is an aluminum alloy for die casting containing Si specified in JIS H 2118: 2006. The ADC 12 is an aluminum alloy containing Cu in a range of 1.5 mass% to 3.5 mass% and Si in a range of 9.6 mass% to 12.0 mass%. The Si content in the cast aluminum alloy is preferably 1% by mass to 25% by mass, but is not limited thereto.
　このヒートシンク３１の金属層１３（Ｃｕ層１３Ｂ）との接合界面側には、図２に示すように、結晶粒のアスペクト比（長径／短径）が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層３５が形成されている。上記Ｓｉ相の結晶粒のアスペクト比（長径／短径）は、好ましくは１．０以上２．０以下、より好ましくは１．０以上１．５であり、結晶粒径は、好ましくは０．５μｍ以上１０μｍ以下、より好ましくは１μｍ以上７μｍ以下であるが、これに限定されることはない。
　このチル層３５は、ヒートシンク３１を構成する鋳造材を形成する際に、鋳造材の表層部分（鋳型近傍部分）に形成されるものであり、鋳造材の内部と比較して、結晶粒径が微細で、アスペクト比が小さくされている。
　そして、ヒートシンク付パワーモジュール用基板３０のチル層３５の厚さ（接合後のチル層の厚さ）は、５０μｍ以上とされている。チル層３５の厚さは、好ましくは１００μｍ以上であり、より好ましくは２００μｍ以上であるが、これに限定されることはない。 As shown in FIG. 2, the heat sink 31 has a crystal grain aspect ratio (major axis / minor axis) of 2.5 or less and a crystal grain size of 15 μm or less on the side of the joint interface with the metal layer 13 (Cu layer 13B). A chill layer 35 in which the Si phase is dispersed is formed. The aspect ratio (major axis / minor axis) of the crystal grains of the Si phase is preferably 1.0 or more and 2.0 or less, more preferably 1.0 or more and 1.5, and the crystal grain size is preferably 0.00. Although it is 5 micrometers or more and 10 micrometers or less, More preferably, they are 1 micrometer or more and 7 micrometers or less, However It is not limited to this.
The chill layer 35 is formed on a surface layer portion (a portion in the vicinity of the mold) of the cast material when the cast material constituting the heat sink 31 is formed. Compared with the inside of the cast material, the chill layer 35 has a crystal grain size. It is fine and has a small aspect ratio.
And the thickness (thickness of the chill layer after joining) of the chill layer 35 of the power module substrate 30 with a heat sink is 50 μm or more. The thickness of the chill layer 35 is preferably 100 μm or more, more preferably 200 μm or more, but is not limited thereto.
　ここで、ヒートシンク３１と金属層１３（Ｃｕ層１３Ｂ）とは、固相拡散接合されている。
　金属層１３（Ｃｕ層１３Ｂ）とヒートシンク３１との接合界面には、図２に示すように、金属間化合物層３８が形成されている。すなわち、ヒートシンク３１のチル層３５の上に金属間化合物層３８が積層されている。
　この金属間化合物層３８は、ヒートシンク３１のＡｌ原子と、Ｃｕ層１３ＢのＣｕ原子とが相互拡散することによって形成される。この金属間化合物層３８においては、ヒートシンク３１からＣｕ層１３Ｂに向かうにしたがい、漸次Ａｌ原子の濃度が低くなり、かつＣｕ原子の濃度が高くなる濃度勾配を有している。 Here, the heat sink 31 and the metal layer 13 (Cu layer 13B) are solid phase diffusion bonded.
As shown in FIG. 2, an intermetallic compound layer 38 is formed at the bonding interface between the metal layer 13 (Cu layer 13 </ b> B) and the heat sink 31. That is, the intermetallic compound layer 38 is laminated on the chill layer 35 of the heat sink 31.
The intermetallic compound layer 38 is formed by mutual diffusion of Al atoms of the heat sink 31 and Cu atoms of the Cu layer 13B. This intermetallic compound layer 38 has a concentration gradient in which the concentration of Al atoms gradually decreases and the concentration of Cu atoms increases as it goes from the heat sink 31 to the Cu layer 13B.
　この金属間化合物層３８は、ＣｕとＡｌからなる金属間化合物で構成されており、本実施形態では、複数の金属間化合物が接合界面に沿って積層した構造とされている。ここで、金属間化合物層３８の厚さは、１μｍ以上８０μｍ以下の範囲内、好ましくは、５μｍ以上８０μｍ以下の範囲内に設定されている。
　なお、この金属間化合物層３８は、Ｃｕ層１３ＢのＣｕがヒートシンク３１（チル層３５）側に拡散することで形成されており、金属間化合物層３８の中には、ヒートシンク３１に含まれるＳｉ粒子が分散している。 The intermetallic compound layer 38 is composed of an intermetallic compound composed of Cu and Al. In the present embodiment, the intermetallic compound layer 38 has a structure in which a plurality of intermetallic compounds are stacked along the bonding interface. Here, the thickness of the intermetallic compound layer 38 is set in the range of 1 μm to 80 μm, preferably in the range of 5 μm to 80 μm.
The intermetallic compound layer 38 is formed by diffusing Cu of the Cu layer 13B toward the heat sink 31 (chill layer 35), and the intermetallic compound layer 38 includes Si contained in the heat sink 31. The particles are dispersed.
　本実施形態では、金属間化合物層３８は、３種の金属間化合物が積層された構造とされており、ヒートシンク３１側からＣｕ層１３Ｂ側に向けて順に、ヒートシンク３１とＣｕ層１３Ｂとの接合界面に沿って、θ相、η２相が積層し、さらにζ２相、δ相、及びγ２相のうち少なくとも一つの相が積層して構成されている。 In the present embodiment, the intermetallic compound layer 38 has a structure in which three kinds of intermetallic compounds are laminated, and the heat sink 31 and the Cu layer 13B are joined in order from the heat sink 31 side to the Cu layer 13B side. A θ phase and a η 2 phase are stacked along the interface, and at least one of a ζ 2 phase, a δ phase, and a γ 2 phase is stacked.
　また、この金属間化合物層とＣｕ層１３Ｂとの接合界面には、酸化物が接合界面に沿って層状に分散している。なお、本実施形態においては、この酸化物は、アルミナ（Ａｌ２Ｏ３）等のアルミニウム酸化物とされている。なお、酸化物は、金属間化合物層とＣｕ層１３Ｂとの界面に分断された状態で分散しており、金属間化合物層とＣｕ層１３Ｂとが直接接触している領域も存在している。また、酸化物がθ相、η２相もしくは、ζ２相、δ相、及びγ２相のうち少なくとも一つの相の内部に層状に分散している場合もある。 In addition, oxides are dispersed in layers along the bonding interface at the bonding interface between the intermetallic compound layer and the Cu layer 13B. In the present 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 layers within at least one of the θ phase, η 2 phase, or ζ 2 phase, δ phase, and γ 2 phase.
　次に、本実施形態であるヒートシンク付パワーモジュール用基板３０の製造方法について、図３から図５を参照して説明する。 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.
（アルミニウム板積層工程Ｓ０１）
　まず、図４に示すように、セラミックス基板１１の一方の面に、回路層１２となるアルミニウム板２２を、Ａｌ－Ｓｉ系のろう材箔２６を介して積層する。
　また、セラミックス基板１１の他方の面に、Ａｌ層１３Ａとなるアルミニウム板２３Ａを、Ａｌ－Ｓｉ系のろう材箔２６を介して積層する。なお、本実施形態では、Ａｌ－Ｓｉ系のろう材箔２６として、厚さ１０μｍのＡｌ－８質量％Ｓｉ合金箔を用いた。 (Aluminum plate lamination step S01)
First, as shown in FIG. 4, an aluminum plate 22 to be 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, an aluminum plate 23A to be the Al layer 13A is laminated on the other surface of the ceramic substrate 11 with an Al—Si based brazing material foil 26 interposed therebetween. 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.
（回路層及びＡｌ層形成工程Ｓ０２）
　そして、積層方向に加圧（圧力１～３５ｋｇｆ／ｃｍ２（０．１０～３．４３ＭＰａ））した状態で真空加熱炉内に配置し加熱して、アルミニウム板２２とセラミックス基板１１を接合して回路層１２を形成する。また、セラミックス基板１１とアルミニウム板２３Ａを接合してＡｌ層１３Ａを形成する。
　ここで、真空加熱炉内の圧力は１０－６Ｐａ以上１０－３Ｐａ以下の範囲内に、加熱温度は６００℃以上６５０℃以下、保持時間は３０分以上１８０分以下の範囲内に設定されることが好ましい。 (Circuit layer and Al layer forming step S02)
Then, the aluminum plate 22 and the ceramic substrate 11 are joined by placing and heating in a vacuum heating furnace under pressure in the laminating direction (pressure 1 to 35 kgf / cm 2 (0.10 to 3.43 MPa)). The circuit layer 12 is formed. Further, 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 in the range of 10 −6 Pa to 10 −3 Pa, the heating temperature is set to 600 ° C. to 650 ° C., and the holding time is set in the range of 30 minutes to 180 minutes. It is preferable.
（Ｃｕ層（金属層）形成工程Ｓ０３）
　次に、Ａｌ層１３Ａの他方の面側に、Ｃｕ層１３Ｂとなる銅板２３Ｂを積層する。
　そして、積層方向に加圧（圧力３～３５ｋｇｆ／ｃｍ２（０．２９～３．４３ＭＰａ））した状態で真空加熱炉内に配置し加熱して、Ａｌ層１３Ａと銅板２３Ｂとを固相拡散接合し、金属層１３を形成する。
　ここで、真空加熱炉内の圧力は１０－６Ｐａ以上１０－３Ｐａ以下の範囲内に、加熱温度は４００℃以上５４８℃以下、保持時間は５分以上２４０分以下の範囲内に設定されることが好ましい。
　なお、Ａｌ層１３Ａ、銅板２３Ｂのうち固相拡散接合されるそれぞれの接合面は、予め当該面の傷が除去されて平滑にされている。 (Cu layer (metal layer) formation 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 diffused by placing them in a vacuum heating furnace under pressure in the stacking direction (pressure 3 to 35 kgf / cm 2 (0.29 to 3.43 MPa)). The metal layer 13 is formed by bonding.
Here, the pressure in the vacuum heating furnace is set within the range of 10 −6 Pa to 10 −3 Pa, the heating temperature is set to 400 ° C. to 548 ° C., and the holding time is set within the range of 5 minutes to 240 minutes. It is preferable.
In addition, each surface of the Al layer 13A and the copper plate 23B to be solid-phase diffusion bonded is previously smoothed by removing scratches on the surfaces.
（ヒートシンク準備工程Ｓ０４）
　次に、接合するヒートシンク３１を準備する。このとき、図５に示すように、ヒートシンク３１のうち金属層１３（Ｃｕ層１３Ｂ）と接合される接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下とされたチル層３５Ａを形成するとともに、このチル層３５Ａの厚さを８０μｍ以上とする。チル層３５Ａの厚さは、好ましくは１００μｍ以上、より好ましくは２００μｍ以上であるが、これに限定されることはない。
　ここで、ヒートシンク３１を鋳造する際にヒートシンク３１の少なくとも接合面近傍の冷却速度を調整することで上述のチル層３５Ａの厚さを制御することができる。この場合、例えば、鋳造する際の金型の温度を２３０℃以下、望ましくは、２１０℃以下とするとよい。鋳造する際の金型の温度は、１４０℃以上、望ましくは、１６０℃以上としてもよい。
　また、ヒートシンクを鋳造する際の条件として、例えば、圧入圧力４００ｋｇ／ｃｍ２～６００ｋｇ／ｃｍ２、溶湯温度６５０℃～７５０℃、湯口速度３０ｍ／ｓ～６０ｍ／ｓ、スリーブ充填率４０％～６０％とすることができる。雰囲気としては、窒素やアルゴン等の不活性雰囲気、酸素雰囲気、真空雰囲気等とすることができる。
　また、鋳造後に表面の研削量を調整することで、チル層３５Ａの厚さを制御することもできる。 (Heat sink preparation step S04)
Next, a heat sink 31 to be joined is prepared. At this time, as shown in FIG. 5, the crystal grain has an aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less on the side of the heat sink 31 where the metal layer 13 (Cu layer 13B) is joined. The chill layer 35A is formed, and the thickness of the chill layer 35A is set to 80 μm or more. The thickness of the chill layer 35A is preferably 100 μm or more, more preferably 200 μm or more, but is not limited thereto.
Here, when casting the heat sink 31, the thickness of the chill layer 35A described above can be controlled by adjusting the cooling rate of at least the vicinity of the joint surface of the heat sink 31. In this case, for example, the temperature of the mold during casting is 230 ° C. or lower, preferably 210 ° C. or lower. The mold temperature during casting may be 140 ° C. or higher, and preferably 160 ° C. or higher.
The conditions for casting the heat sink include, for example, a press-fitting pressure of 400 kg / cm 2 to 600 kg / cm 2 , a molten metal temperature of 650 ° C. to 750 ° C., a gate speed of 30 m / s to 60 m / s, and a sleeve filling rate of 40% to 60 %. The atmosphere may be an inert atmosphere such as nitrogen or argon, an oxygen atmosphere, a vacuum atmosphere, or the like.
Further, the thickness of the chill layer 35A can be controlled by adjusting the grinding amount of the surface after casting.
（金属層／ヒートシンク接合工程Ｓ０５）
　次に、金属層１３（Ｃｕ層１３Ｂ）とヒートシンク３１とを積層し、積層方向に加圧（圧力５～３５ｋｇｆ／ｃｍ２（０．４９～３．４３ＭＰａ））した状態で真空加熱炉内に配置し加熱して、金属層１３（Ｃｕ層１３Ｂ）とヒートシンク３１を固相拡散接合する。なお、金属層１３（Ｃｕ層１３Ｂ）及びヒートシンク３１のうち固相拡散接合されるそれぞれの接合面は、予め当該面の傷が除去されて平滑にされている。加圧の際の圧力は、より好ましくは８～２０ｋｇｆ／ｃｍ２（０．７８～１．９６ＭＰａ）であるが、これに限定されることはない。
　ここで、真空加熱炉内の圧力は１０－６Ｐａ以上１０－３Ｐａ以下の範囲内に、加熱温度は４００℃以上５２０℃以下、保持時間は０．２５時間以上３時間以下の範囲内に設定されることが好ましい。真空加熱炉内の圧力は、１０－５Ｐａ以上１０－４Ｐａ以下の範囲内に、加熱温度は４８０℃以上５１０℃以下、保持時間は０．５時間以上２時間以下の範囲内に設定されることがより好ましいが、これに限定されることはない。
　この金属層／ヒートシンク接合工程Ｓ０５において、Ｃｕ層１３Ｂ中のＣｕ原子がヒートシンク３１のチル層３５Ａ側に拡散していき、図２に示すように、金属間化合物層３８及びチル層３５が形成される。
　このようにして、本実施形態であるヒートシンク付パワーモジュール用基板３０が製造される。 (Metal layer / heat sink bonding step S05)
Next, the metal layer 13 (Cu layer 13B) and the heat sink 31 are stacked and pressurized in the stacking direction (pressure 5 to 35 kgf / cm 2 (0.49 to 3.43 MPa)) in a vacuum heating furnace. The metal layer 13 (Cu layer 13B) and the heat sink 31 are solid-phase diffusion bonded by arranging and heating. In addition, each joining surface of the metal layer 13 (Cu layer 13 </ b> B) and the heat sink 31 to be solid phase diffusion bonded is previously smoothed by removing scratches on the surfaces. The pressure during the pressurization is more preferably 8 to 20 kgf / cm 2 (0.78 to 1.96 MPa), but is not limited thereto.
Here, the pressure in the vacuum heating furnace is in the range of 10 −6 Pa to 10 −3 Pa, the heating temperature is 400 ° C. to 520 ° C., and the holding time is in the range of 0.25 hour to 3 hours. Preferably it is set. The pressure in the vacuum heating furnace is set in the range of 10 −5 Pa to 10 −4 Pa, the heating temperature is set to 480 ° C. to 510 ° C., and the holding time is set in the range of 0.5 hours to 2 hours. Although it is more preferable, it is not limited to this.
In this metal layer / heat sink joining step S05, Cu atoms in the Cu layer 13B diffuse to the chill layer 35A side of the heat sink 31, and as shown in FIG. 2, an intermetallic compound layer 38 and a chill layer 35 are formed. The
In this way, the power module substrate with heat sink 30 according to the present embodiment is manufactured.
（半導体素子接合工程Ｓ０６）
　次いで、回路層１２の一方の面（表面（図１において上側））に、はんだ材２を介して半導体素子３を積層し、還元炉内においてはんだ接合する。
　上記のようにして、本実施形態であるパワーモジュール１が製造される。 (Semiconductor element bonding step S06)
Next, the semiconductor element 3 is laminated on one surface (surface (upper side in FIG. 1)) of the circuit layer 12 via the solder material 2 and soldered in a reduction furnace.
As described above, the power module 1 according to the present embodiment is manufactured.
　以上のような構成とされた本実施形態に係るヒートシンク付パワーモジュール用基板３０によれば、ヒートシンク３１が、固相線温度が金属層１３の接合面（Ｃｕ層１３Ｂ）を構成するＣｕとＡｌとの共晶温度（５４８℃）未満とされたアルミニウム合金で構成されており、具体的には、ＪＩＳ　Ｈ　２１１８：２００６で規定されたダイカスト用アルミニウム合金であるＡＤＣ１２（固相線温度５１５℃）の鋳造材で構成されているので、流路３２を有する複雑な構造のヒートシンク３１を構成することができ、放熱性能を向上させることが可能となる。 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 includes Cu and Al whose solidus temperature forms 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 formed, and the heat dissipation performance can be improved.
　そして、本実施形態では、ヒートシンク３１のうち金属層１３（Ｃｕ層１３Ｂ）との接合界面側に、結晶粒のアスペクト比（長径／短径）が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層３５が形成されており、このチル層３５の厚さが５０μｍ以上とされているので、このチル層３５によって金属層１３（Ｃｕ層１３Ｂ）のＣｕ原子の拡散移動が妨げられることになり、カーケンダルボイドの発生を抑制することができる。よって、このヒートシンク付パワーモジュール用基板３０を高温に保持した場合であっても、積層方向における熱抵抗が上昇せず、放熱特性の劣化を抑制することが可能となる。 In this embodiment, the crystal grain aspect ratio (major axis / minor axis) is 2.5 or less and the crystal grain size is 15 μm or less on the bonding interface side of the heat sink 31 with the metal layer 13 (Cu layer 13B). Since a chill layer 35 in which a certain Si phase is dispersed is formed, and the thickness of the chill layer 35 is 50 μm or more, diffusion movement of Cu atoms in the metal layer 13 (Cu layer 13B) is caused by the chill layer 35. Can be prevented, and the generation of Kirkendall void can be suppressed. Therefore, even when the power module substrate with heat sink 30 is held at a high temperature, the thermal resistance in the stacking direction does not increase, and deterioration of the heat dissipation characteristics can be suppressed.
　さらに、本実施形態では、金属層１３（Ｃｕ層１３Ｂ）とヒートシンク３１との接合界面に、ＣｕとＡｌの金属間化合物層からなる金属間化合物層３８が形成されている。この金属間化合物層３８は、複数の金属間化合物が接合界面に沿って積層した構造とされているので、脆い金属間化合物が大きく成長してしまうことを抑制できる。また、金属間化合物層３８内部における体積変動が小さくなり、内部歪みが抑えられる。
　また、本実施形態では、Ｃｕ層１３Ｂと金属間化合物層３８との接合界面においては、酸化物がこれらの接合界面に沿ってそれぞれ層状に分散しているので、ヒートシンク３１の接合面に形成された酸化膜が確実に破壊され、ＣｕとＡｌの相互拡散が十分に進行していることになり、Ｃｕ層１３Ｂとヒートシンク３１とが確実に接合される。 Furthermore, in this embodiment, an intermetallic compound layer 38 made of an intermetallic compound layer of Cu and Al is formed at the bonding interface between the metal layer 13 (Cu layer 13B) and the heat sink 31. Since the intermetallic compound layer 38 has a structure in which a plurality of intermetallic compounds are laminated along the bonding interface, the brittle intermetallic compound can be prevented from growing greatly. Further, the volume variation inside the intermetallic compound layer 38 is reduced, and internal strain is suppressed.
Further, in the present embodiment, at the bonding interface between the Cu layer 13 </ b> B and the intermetallic compound layer 38, oxides are dispersed in layers along these bonding interfaces, so that they are formed on the bonding surface of the heat sink 31. Thus, the oxide film is surely broken, and the mutual diffusion of Cu and Al is sufficiently advanced, so that the Cu layer 13B and the heat sink 31 are reliably bonded.
　また、本実施形態のヒートシンク付パワーモジュール用基板３０の製造方法によれば、ヒートシンク準備工程Ｓ０４において、接合前のヒートシンク３１として、ヒートシンク３１のうち金属層１３（Ｃｕ層１３Ｂ）と接合される接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層３５Ａを形成するとともに、このチル層３５Ａの厚さを８０μｍ以上とした構成のものを準備しているので、金属層／ヒートシンク接合工程Ｓ０５において、ヒートシンク３１と金属層１３（Ｃｕ層１３Ｂ）を固相拡散接合した際に、Ｃｕ層１３ＢのＣｕ原子が必要以上に拡散移動することを抑制でき、カーケンダルボイドの発生を抑制することができる。
　よって、積層方向における熱抵抗が低く、放熱特性に優れたヒートシンク付パワーモジュール用基板３０を製造することが可能となる。 Moreover, according to the manufacturing method of the power module substrate 30 with a heat sink of this embodiment, in the heat sink preparation step S04, as the heat sink 31 before bonding, the bonding to be bonded to the metal layer 13 (Cu layer 13B) in the heat sink 31. A chill layer 35A in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is formed on the surface side, and the thickness of the chill layer 35A is set to 80 μm or more. In the metal layer / heat sink bonding step S05, when the heat sink 31 and the metal layer 13 (Cu layer 13B) are solid phase diffusion bonded, Cu atoms in the Cu layer 13B diffuse and move more than necessary. This can be suppressed, and the generation of Kirkendall void can be suppressed.
Therefore, it is possible to manufacture the power module substrate 30 with a heat sink having a low thermal resistance in the stacking direction and excellent heat dissipation characteristics.
　さらに、固相拡散接合する際に、接合面に傷がある場合には接合界面に隙間が生じるおそれがあるが、本実施形態では、Ｃｕ層１３Ｂ（銅板２３Ｂ）、ヒートシンク３１の接合される面は、予め当該面の傷が除去されて平滑にされた後に固相拡散接合されているので、接合界面に隙間が生じることを抑制することができ、確実に固相拡散接合することができる。
　なお、通常、鋳造材からなるヒートシンク３１を表面研削する際には、表層に薄く形成されたチル層を除去することになるが、本実施形態では、鋳造時にチル層を厚く形成し、表面研削においてチル層を残存させている。 Furthermore, when solid-phase diffusion bonding is performed, if there is a scratch on the bonding surface, a gap may be formed at the bonding interface, but in this embodiment, the Cu layer 13B (copper plate 23B) and the surface to which the heat sink 31 is bonded. Since the solid-phase diffusion bonding is performed after the surface scratches have been removed and smoothed in advance, the formation of a gap at the bonding interface can be suppressed, and solid-phase diffusion bonding can be reliably performed.
Normally, when the surface of the heat sink 31 made of a cast material is ground, the chill layer formed thinly on the surface layer is removed. However, in this embodiment, the chill layer is formed thick during casting and surface grinding is performed. The chill layer remains.
　本実施形態において、チル層の厚さの上限は特に制限されないが、鋳造材からなるヒートシンク３１を用いる場合、５０００μｍ以下とすることが好ましい。鋳造によりヒートシンク３１を製造する場合、チル層の厚さが５０００μｍを超えるように製造することは困難である。
　また、ヒートシンク３１が薄い場合には、ヒートシンク３１全体がチル層となる場合もある。この場合であっても、本実施形態と同様の作用効果を奏することが可能である。 In the present embodiment, the upper limit of the thickness of the chill layer is not particularly limited, but when the heat sink 31 made of a cast material is used, it is preferably set to 5000 μm or less. When the heat sink 31 is manufactured by casting, it is difficult to manufacture the heat sink 31 so that the thickness of the chill layer exceeds 5000 μm.
When the heat sink 31 is thin, the entire heat sink 31 may be a chill layer. Even in this case, it is possible to achieve the same effects as the present embodiment.
（第二実施形態）
　次に、本発明の第二実施形態であるヒートシンクについて説明する。図６に、本発明の第二実施形態に係るヒートシンク１０１を示す。
　このヒートシンク１０１は、ヒートシンク本体１１０と、ヒートシンク本体１１０の一方の面（図６において上側）に積層された銅、ニッケル又は銀からなる金属部材層１１７と、を備えている。本実施形態では、金属部材層１１７は、図９に示すように、無酸素銅の圧延板からなる金属板１２７を接合することによって構成されている。 (Second embodiment)
Next, the heat sink which is 2nd embodiment of this invention is demonstrated. FIG. 6 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 of the heat sink body 110 (upper side in FIG. 6). In this embodiment, as shown in FIG. 9, the metal member layer 117 is configured by joining a metal plate 127 made of an oxygen-free copper rolled plate.
　ヒートシンク本体１１０は、冷却媒体が流通する流路１１１が設けられている。このヒートシンク本体１１０は、固相線温度が金属部材層１１７を構成する金属元素（本実施形態ではＣｕ）とＡｌとの共晶温度（５４８℃）未満とされたアルミニウム合金で構成されており、具体的には、ＪＩＳ　Ｈ　２１１８：２００６で規定されたＳｉを含有するダイカスト用アルミニウム合金であるＡＤＣ１４（固相線温度５０７℃）の鋳造材で構成されている。なお、このＡＤＣ１４は、Ｓｉを１６質量％～１８質量％、Ｍｇを０．４５質量％～０．６５質量％の範囲内で含むアルミニウム合金である。アルミニウム合金におけるＳｉ含有量は、好ましくは１質量％～２５質量％であるが、これに限定されることはない。 The heat sink body 110 is provided with a flow path 111 through which a cooling medium flows. This heat sink body 110 is made of an aluminum alloy whose solidus temperature is less than the eutectic temperature (548 ° C.) of the metal element (Cu in this embodiment) and Al constituting the metal member layer 117, Specifically, it is made of a cast material of ADC14 (solidus temperature 507 ° C.) which is an aluminum alloy for die casting containing Si specified in JIS H 2118: 2006. The ADC 14 is an aluminum alloy containing Si in a range of 16% by mass to 18% by mass and Mg in a range of 0.45% by mass to 0.65% by mass. The Si content in the aluminum alloy is preferably 1% by mass to 25% by mass, but is not limited thereto.
　そして、このヒートシンク本体１１０の金属部材層１１７との接合界面側には、図７に示すように、結晶粒のアスペクト比（長径／短径）が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層１３５が形成されている。上記Ｓｉ相の結晶粒のアスペクト比（長径／短径）は、好ましくは１．０以上２．０以下、より好ましくは１．０以上１．５であり、結晶粒径は、好ましくは０．５μｍ以上１０μｍ以下、より好ましくは１μｍ以上７μｍ以下であるが、これに限定されることはない。
　このチル層１３５は、ヒートシンク本体１１０を構成する鋳造材を形成する際に、鋳造材の表層部分（鋳型近傍部分）に形成されるものであり、鋳造材の内部と比較して、結晶粒径が微細で、アスペクト比が小さくされている。
　このチル層１３５の厚さは、５０μｍ以上とされている。チル層１３５の厚さは、好ましくは１００μｍ以上であり、より好ましくは２００μｍ以上であるが、これに限定されることはない。 As shown in FIG. 7, the heat sink body 110 has a crystal grain aspect ratio (major axis / minor axis) of 2.5 or less and a crystal grain size of 15 μm or less. A chill layer 135 in which a certain Si phase is dispersed is formed. The aspect ratio (major axis / minor axis) of the crystal grains of the Si phase is preferably 1.0 or more and 2.0 or less, more preferably 1.0 or more and 1.5, and the crystal grain size is preferably 0.00. Although it is 5 micrometers or more and 10 micrometers or less, More preferably, they are 1 micrometer or more and 7 micrometers or less, However It is not limited to this.
The chill layer 135 is formed on a surface layer portion (a portion near the mold) of the cast material when forming the cast material constituting the heat sink body 110, and has a crystal grain size as compared with the inside of the cast material. Is fine and has a small aspect ratio.
The chill layer 135 has a thickness of 50 μm or more. The thickness of the chill layer 135 is preferably 100 μm or more, more preferably 200 μm or more, but is not limited thereto.
　ここで、ヒートシンク本体１１０と金属部材層１１７は、固相拡散接合されている。
　ヒートシンク本体１１０と金属部材層１１７との接合界面には、図７に示すように、金属間化合物層１３８が形成されている。この金属間化合物層１３８は、ヒートシンク本体１１０のＡｌ原子と、金属部材層１１７のＣｕ原子とが相互拡散することによって形成されている。この金属間化合物層１３８においては、ヒートシンク本体１１０から金属部材層１１７に向かうにしたがい、漸次Ａｌ原子の濃度が低くなり、かつＣｕ原子の濃度が高くなる濃度勾配を有している。 Here, the heat sink body 110 and the metal member layer 117 are solid phase diffusion bonded.
As shown in FIG. 7, an intermetallic compound layer 138 is formed at the bonding interface between the heat sink body 110 and the metal member layer 117. The intermetallic compound layer 138 is formed by mutual diffusion of Al atoms in the heat sink body 110 and Cu atoms in the metal member layer 117. The intermetallic compound layer 138 has a concentration gradient in which the Al atom concentration gradually decreases and the Cu atom concentration increases as the heat sink body 110 moves toward the metal member layer 117.
　この金属間化合物層１３８は、ＣｕとＡｌからなる金属間化合物で構成されており、本実施形態では、複数の金属間化合物が接合界面に沿って積層した構造とされている。ここで、金属間化合物層１３８の厚さは、１μｍ以上８０μｍ以下の範囲内、好ましくは、５μｍ以上８０μｍ以下の範囲内に設定されている。
　なお、この金属間化合物層１３８は、金属部材層１１７のＣｕがヒートシンク本体１１０（チル層１３５）側に拡散することで形成されており、金属間化合物層１３８の中には、ヒートシンク本体１１０に含まれるＭｇ粒子が分散している場合もある。 The intermetallic compound layer 138 is composed of an intermetallic compound composed of Cu and Al. In the present embodiment, the intermetallic compound layer 138 has a structure in which a plurality of intermetallic compounds are stacked along the bonding interface. Here, the thickness of the intermetallic compound layer 138 is set in the range of 1 μm to 80 μm, preferably in the range of 5 μm to 80 μm.
The intermetallic compound layer 138 is formed by diffusing Cu of the metal member layer 117 toward the heat sink body 110 (chill layer 135), and the intermetallic compound layer 138 includes the heat sink body 110 on the heat sink body 110. The Mg particles contained may be dispersed.
　本実施形態では、金属間化合物層１３８は、３種の金属間化合物が積層された構造とされており、ヒートシンク本体１１０側から金属部材層１１７側に向けて順に、ヒートシンク本体１１０と金属部材層１１７との接合界面に沿って、θ相、η２相が積層し、さらにζ２相、δ相、及びγ２相のうち少なくとも一つの相が積層して構成されている
　また、この金属間化合物層１３８と金属部材層１１７との接合界面には、酸化物が接合界面に沿って層状に分散している。なお、本実施形態においては、この酸化物は、アルミナ（Ａｌ２Ｏ３）等のアルミニウム酸化物とされている。なお、酸化物は、金属間化合物層１３８と金属部材層１１７との界面に分断された状態で分散しており、金属間化合物層１３８と金属部材層１１７とが直接接触している領域も存在している。また、酸化物が、θ相、η２相もしくは、ζ２相、δ相、及びγ２相のうち少なくとも一つの相の内部に層状に分散している場合もある。 In the present embodiment, the intermetallic compound layer 138 has a structure in which three kinds of intermetallic compounds are laminated, and the heat sink body 110 and the metal member layer are sequentially arranged from the heat sink body 110 side to the metal member layer 117 side. The θ phase and η 2 phase are laminated along the bonding interface with 117, and at least one of the ζ 2 phase, δ phase, and γ 2 phase is laminated. At the bonding interface between the compound layer 138 and the metal member layer 117, the oxide is dispersed in layers along the bonding interface. 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 intermetallic compound layer 138 and the metal member layer 117, and there is a region where the intermetallic compound layer 138 and the metal member layer 117 are in direct contact with each other. is doing. In some cases, the oxide is dispersed in layers within at least one of the θ phase, the η 2 phase, or the ζ 2 phase, the δ phase, and the γ 2 phase.
　次に、本実施形態であるヒートシンク１０１の製造方法について、図８及び図９を参照して説明する。 Next, the manufacturing method of the heat sink 101 which is this embodiment is demonstrated with reference to FIG.8 and FIG.9.
（ヒートシンク本体準備工程Ｓ１０１）
　まず、接合するヒートシンク本体１１０を準備する。このとき、ヒートシンク本体１１０のうち金属部材層１１７と接合される接合面側に、第一実施形態で説明したヒートシンク３１（図５参照）と同様に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上とする。このチル層の厚さは、好ましくは１００μｍ以上、より好ましくは２００μｍ以上であるが、これに限定されることはない。
　ここで、ヒートシンク本体１１０を鋳造する際にヒートシンク本体１１０の少なくとも接合面近傍の冷却速度を調整することで上述のチル層の厚さを制御することができる。この場合、例えば、鋳造する際の金型の温度を２３０℃以下、望ましくは、２１０℃以下とするとよい。鋳造する際の金型の温度は、１４０℃以上、望ましくは、１６０℃以上としてもよい。また、ヒートシンクを鋳造する際の条件として、例えば、圧入圧力４００ｋｇ／ｃｍ２～６００ｋｇ／ｃｍ２、溶湯温度６５０℃～７５０℃、湯口速度３０ｍ／ｓ～６０ｍ／ｓ、スリーブ充填率４０％～６０％とすることができる。雰囲気としては、窒素やアルゴン等の不活性雰囲気、酸素雰囲気、真空雰囲気等とすることができる。
　また、鋳造後に表面の研削量を調整することで、チル層の厚さを制御することもできる。 (Heat sink body preparation step S101)
First, the heat sink body 110 to be joined is prepared. At this time, the crystal grain aspect ratio is 2.5 or less, similar to the heat sink 31 described in the first embodiment (see FIG. 5), on the bonding surface side of the heat sink body 110 to be bonded to the metal member layer 117. A chill layer in which the Si phase having a crystal grain size of 15 μm or less is dispersed and the thickness of the chill layer is set to 80 μm or more. The thickness of the chill layer is preferably 100 μm or more, more preferably 200 μm or more, but is not limited thereto.
Here, when the heat sink body 110 is cast, the thickness of the chill layer can be controlled by adjusting the cooling rate at least in the vicinity of the joint surface of the heat sink body 110. In this case, for example, the temperature of the mold during casting is 230 ° C. or lower, preferably 210 ° C. or lower. The mold temperature during casting may be 140 ° C. or higher, and preferably 160 ° C. or higher. The conditions for casting the heat sink include, for example, a press-fitting pressure of 400 kg / cm 2 to 600 kg / cm 2 , a molten metal temperature of 650 ° C. to 750 ° C., a gate speed of 30 m / s to 60 m / s, and a sleeve filling rate of 40% to 60 %. The atmosphere may be an inert atmosphere such as nitrogen or argon, an oxygen atmosphere, a vacuum atmosphere, or the like.
Also, the thickness of the chill layer can be controlled by adjusting the surface grinding amount after casting.
（ヒートシンク本体／金属部材層接合工程Ｓ１０２）
　次に、図９に示すように、ヒートシンク本体１１０と金属部材層１１７となる金属板１２７とを積層し、積層方向に加圧（圧力１～３５ｋｇｆ／ｃｍ２（０．１０～３．４３ＭＰａ））した状態で真空加熱炉内に配置し加熱することにより、金属板１２７とヒートシンク本体１１０とを固相拡散接合する。なお、金属板１２７、ヒートシンク本体１１０のうち固相拡散接合されるそれぞれの接合面は、予め当該面の傷が除去されて平滑にされている。加圧の際の圧力は、より好ましくは８～２０ｋｇｆ／ｃｍ２（０．７８～１．９６ＭＰａ）であるが、これに限定されることはない。
　ここで、真空加熱炉内の圧力は１０－６Ｐａ以上１０－３Ｐａ以下の範囲内に、加熱温度は４００℃以上５２０℃以下、保持時間は０．２５時間以上３時間以下の範囲内に設定されることが好ましい。真空加熱炉内の圧力は、１０－５Ｐａ以上１０－４Ｐａ以下の範囲内に、加熱温度は４８０℃以上５１０℃以下、保持時間は０．５時間以上２時間以下の範囲内に設定されることがより好ましいが、これに限定されることはない。
　このヒートシンク本体／金属部材層接合工程Ｓ１０２において、金属板１２７中のＣｕ原子がヒートシンク本体１１０のチル層側に拡散していき、図７に示すように、金属間化合物層１３８とチル層１３５とが形成される。
　このようにして、本実施形態であるヒートシンク１０１が製造される。 (Heat sink body / metal member layer joining step S102)
Next, as shown in FIG. 9, the heat sink body 110 and the metal plate 127 to be the metal member layer 117 are laminated, and pressure is applied in the laminating direction (pressure 1 to 35 kgf / cm 2 (0.10 to 3.43 MPa). In this state, the metal plate 127 and the heat sink body 110 are solid-phase diffusion bonded by being placed in a vacuum heating furnace and heated. In addition, each joining surface of the metal plate 127 and the heat sink body 110 to be solid phase diffusion bonded is previously smoothed by removing scratches on the surfaces. The pressure during the pressurization is more preferably 8 to 20 kgf / cm 2 (0.78 to 1.96 MPa), but is not limited thereto.
Here, the pressure in the vacuum heating furnace is in the range of 10 −6 Pa to 10 −3 Pa, the heating temperature is 400 ° C. to 520 ° C., and the holding time is in the range of 0.25 hour to 3 hours. It is preferably set. The pressure in the vacuum heating furnace is set in the range of 10 −5 Pa to 10 −4 Pa, the heating temperature is set to 480 ° C. to 510 ° C., and the holding time is set in the range of 0.5 hours to 2 hours. Although it is more preferable, it is not limited to this.
In this heat sink body / metal member layer joining step S102, Cu atoms in the metal plate 127 diffuse toward the chill layer side of the heat sink body 110, and as shown in FIG. 7, the intermetallic compound layer 138, the chill layer 135, Is formed.
Thus, the heat sink 101 which is this embodiment is manufactured.
　以上のような構成とされた本実施形態に係るヒートシンク１０１によれば、ヒートシンク本体１１０の一方の面側に、無酸素銅の圧延板からなる金属板１２７を接合することによって金属部材層１１７が形成されているので、熱を金属部材層１１７によって面方向に広げることができ、放熱特性を大幅に向上させることができる。また、はんだ等を用いて他の部材とヒートシンク１０１とを良好に接合することができる。 According to the heat sink 101 according to the present embodiment configured as described above, the metal member layer 117 is formed by joining the metal plate 127 made of an oxygen-free copper rolled plate to one surface side of the heat sink body 110. Since it is formed, heat can be spread in the surface direction by the metal member layer 117, and the heat dissipation characteristics can be greatly improved. In addition, other members and the heat sink 101 can be favorably bonded using solder or the like.
　また、ヒートシンク本体１１０が、固相線温度が金属部材層１１７を構成する金属元素（Ｃｕ）とＡｌとの共晶温度（５４８℃）未満とされたアルミニウム合金で構成されており、具体的には、ＪＩＳ　Ｈ　２１１８：２００６で規定されたダイカスト用アルミニウム合金であるＡＤＣ１４（固相線温度５０７℃）の鋳造材で構成されているので、流路等を有する複雑な構造のヒートシンク本体１１０を構成することができる。 The heat sink body 110 is made of an aluminum alloy whose solidus temperature is less than the eutectic temperature (548 ° C.) of the metal element (Cu) and Al constituting the metal member layer 117, and specifically, Is composed of a cast material of ADC14 (solidus temperature 507 ° C), which is an aluminum alloy for die casting specified in JIS H 2118: 2006. can do.
　そして、本実施形態では、ヒートシンク本体１１０のうち金属部材層１１７との接合界面側に、結晶粒のアスペクト比（長径／短径）が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層１３５が形成されており、このチル層１３５の厚さが５０μｍ以上とされているので、このチル層１３５によって金属部材層１１７のＣｕ原子の拡散移動が妨げられることになり、カーケンダルボイドの発生を抑制することができる。よって、このヒートシンク１０１を高温に保持した場合であっても、積層方向における熱抵抗が上昇せず、放熱特性の劣化を抑制することが可能となる。 In the present embodiment, the Si phase in which the aspect ratio (major axis / minor axis) of the crystal grains is 2.5 or less and the crystal grain diameter is 15 μm or less is formed on the bonding interface side with the metal member layer 117 in the heat sink body 110. Is formed, and the thickness of the chill layer 135 is 50 μm or more, the diffusion of Cu atoms in the metal member layer 117 is prevented by the chill layer 135, Generation of Kirkendall void can be suppressed. Therefore, even when the heat sink 101 is held at a high temperature, the thermal resistance in the stacking direction does not increase, and it is possible to suppress deterioration of the heat dissipation characteristics.
　また、本実施形態では、金属部材層１１７とヒートシンク本体１１０との接合界面が、第一実施形態のＣｕ層１３Ｂとヒートシンク３１との接合界面と同様の構成とされているので、第一実施形態と同様の作用効果を奏することが可能となる。 In the present embodiment, the bonding interface between the metal member layer 117 and the heat sink body 110 has the same configuration as the bonding interface between the Cu layer 13B and the heat sink 31 in the first embodiment. It is possible to achieve the same function and effect.
　本実施形態において、チル層の厚さの上限は特に制限されないが鋳造材からなるヒートシンク本体１１０を用いる場合、５０００μｍ以下とすることが好ましい。鋳造によりヒートシンク本体１１０を製造する場合、チル層の厚さが５０００μｍを超えるように製造することは困難である。
　また、ヒートシンク本体１１０が薄い場合には、ヒートシンク本体１１０全体がチル層となる場合もある。この場合であっても、本実施形態と同様の作用効果を奏することが可能である。 In the present embodiment, the upper limit of the thickness of the chill layer is not particularly limited, but when the heat sink body 110 made of a cast material is used, it is preferably set to 5000 μm or less. When the heat sink body 110 is manufactured by casting, it is difficult to manufacture the heat sink body 110 so that the thickness of the chill layer exceeds 5000 μm.
When the heat sink body 110 is thin, the entire heat sink body 110 may be a chill layer. Even in this case, it is possible to achieve the same effects as the present embodiment.
　以上、本発明の実施形態について説明したが、本発明はこれに限定されることはなく、その発明の技術的思想を逸脱しない範囲で適宜変更可能である。
　例えば、上記実施の形態では、金属部材層として銅からなるＣｕ層が接合される場合について説明したが、Ｃｕ層に代えて、ニッケル又はニッケル合金からなるＮｉ層、もしくは銀又は銀合金からなるＡｇ層が接合されても良い。 As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, in the above embodiment, the case where a Cu layer made of copper is bonded as the metal member layer has been described. However, instead of the Cu layer, a Ni layer made of nickel or a nickel alloy, or an Ag made of silver or a silver alloy. The layers may be joined.
　Ｃｕ層に代えてＮｉ層を形成した場合には、はんだ付け性が良好となり、他の部材との接合信頼性を向上できる。さらに、固相拡散接合によってＮｉ層を形成する場合には、無電解めっき等でＮｉめっき膜を形成する際に行われるマスキング処理が不要なので、製造コストを低減できる。この場合、Ｎｉ層の厚さは１μｍ以上３０μｍ以下とすることが望ましい。Ｎｉ層の厚さが１μｍ未満の場合には他の部材との接合信頼性を向上させる効果が無くなるおそれがあり、３０μｍを超える場合にはＮｉ層が熱抵抗体となり効率的に熱を伝達できなくなるおそれがある。また、固相拡散接合によってＮｉ層を形成する場合、Ａｌ層とＮｉの固相拡散接合については、接合温度を４００℃以上５２０℃以下に設定するが、その他の条件は前述の実施形態と同様の条件で形成することができる。 When the Ni layer is formed instead of the Cu layer, the solderability is good and the reliability of joining with other members can be improved. Further, 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 not necessary, so that the manufacturing cost can be reduced. In this case, the thickness of the Ni layer is preferably 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 bonding with other members may be lost. If the thickness exceeds 30 μm, the Ni layer becomes a thermal resistor and heat can be transferred efficiently. There is a risk of disappearing. When the Ni layer is formed by solid phase diffusion bonding, the bonding temperature is set to 400 ° C. or more and 520 ° C. or less for the solid phase diffusion bonding of the Al layer and Ni, but other conditions are the same as in the above-described embodiment. It can be formed under the following conditions.
　Ｃｕ層に代えてＡｇ層を形成した場合には、例えば酸化銀粒子と有機物からなる還元剤とを含む酸化銀ペーストを用いて他の部材を接合する際に、酸化銀ペーストの酸化銀が還元剤によって還元された銀と、接合するＡｇ層とが同種の金属同士の接合となるため、接合信頼性を向上させることができる。さらには、熱伝導率の良好なＡｇ層が形成されるので、熱を面方向に拡げて効率的に伝達することができる。この場合、Ａｇ層の厚さは１μｍ以上２０μｍ以下とすることが望ましい。Ａｇ層の厚さが１μｍ未満の場合には他の部材との接合信頼性を向上させる効果が無くなるおそれがあり、２０μｍを超える場合には接合信頼性向上の効果が観られなくなり、コストの増加を招く。また、固相拡散接合によってＡｇ層を形成する場合、Ａｌ層とＡｇの固相拡散接合の条件は、接合温度を４００℃以上５２０℃以下に設定するが、その他は前述の実施形態と同様の条件で形成することができる。 When an Ag layer is formed instead of the Cu layer, for example, when other members are joined using a silver oxide paste containing silver oxide particles and a reducing agent made of an organic material, the silver oxide of the silver oxide paste is reduced. Since the silver reduced by the agent and the Ag layer to be bonded are bonded between the same kind of metals, the bonding reliability can be improved. Furthermore, since an Ag layer having a good thermal conductivity is formed, heat can be spread efficiently by spreading in the surface direction. In this case, the thickness of the Ag layer is preferably 1 μm or more and 20 μm or less. If the thickness of the Ag layer is less than 1 μm, the effect of improving the reliability of bonding with other members may be lost. If the thickness of the Ag layer exceeds 20 μm, the effect of improving the reliability of bonding cannot be observed, resulting in an increase in cost. Invite. In addition, when the Ag layer is formed by solid phase diffusion bonding, the conditions for the solid phase diffusion bonding of the Al layer and Ag are set such that the bonding temperature is 400 ° C. or more and 520 ° C. or less. It can be formed under conditions.
　さらに、第一実施形態では、金属層１３を、Ａｌ層１３ＡとＣｕ層１３Ｂとを有するものとして説明したが、これに限定されることはなく、図１０に示すように、金属層全体を銅又は銅合金で構成してもよい。この図１０に示すヒートシンク付パワーモジュール用基板２３０においては、セラミックス基板１１の他方の面（図１０において下側）に銅板がＤＢＣ法あるいは活性金属ろう付け法等によって接合され、銅又は銅合金からなる金属層２１３が形成されている。そして、この金属層２１３とヒートシンク３１とが、固相拡散接合されている。なお、図１０に示すパワーモジュール用基板２１０においては、回路層２１２も銅又は銅合金によって構成されている。図１０に示すパワーモジュール２０１は、ヒートシンク付パワーモジュール用基板２３０と、このヒートシンク付パワーモジュール用基板２３０の一方の面（図１０において上面）にはんだ層２を介して接合された半導体素子３と、を備えている。 Further, in the first embodiment, the metal layer 13 has been described as having the Al layer 13A and the Cu layer 13B. However, the present invention is not limited to this, and as shown in FIG. Or you may comprise with a copper alloy. In the power module substrate 230 with a heat sink shown in FIG. 10, a copper plate is joined to the other surface (lower side in FIG. 10) of the ceramic substrate 11 by the DBC method, the active metal brazing method, or the like. A metal layer 213 is formed. The metal layer 213 and the heat sink 31 are solid phase diffusion bonded. In the power module substrate 210 shown in FIG. 10, the circuit layer 212 is also made of copper or a copper alloy. A power module 201 shown in FIG. 10 includes a power module substrate 230 with a heat sink, and a semiconductor element 3 bonded to one surface (the upper surface in FIG. 10) of the power module substrate 230 with a heat sink via a solder layer 2. It is equipped with.
　第一実施形態において、回路層を純度９９質量％のアルミニウム板を接合することで形成したものとして説明したが、これに限定されることはなく、純度９９．９９質量％以上の純アルミニウムや、他のアルミニウム又はアルミニウム合金、銅又は銅合金等の他の金属で構成したものであってもよい。また、回路層をＡｌ層とＣｕ層の２層構造のものとしてもよい。これは、図１０に示すパワーモジュール用基板２１０でも同様である。 In the first embodiment, the circuit layer is described as being formed by bonding an aluminum plate having a purity of 99% by mass, but is not limited thereto, and pure aluminum having a purity of 99.99% by mass or more, It may be composed of other metals such as aluminum or aluminum alloy, copper or copper alloy. 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.
　第一の実施形態の金属層／ヒートシンク接合工程Ｓ０５においては、金属層１３（Ｃｕ層１３Ｂ）とヒートシンク３１とを積層し、積層方向に加圧した状態で真空加熱炉内に配置して加熱する構成とし、第二の実施形態のヒートシンク本体／金属部材層接合工程Ｓ１０２においては、ヒートシンク本体１１０と金属部材層１１７となる金属板１２７とを積層し、積層方向に加圧（圧力５～３５ｋｇｆ／ｃｍ２（０．４９～３．４３ＭＰａ））した状態で真空加熱炉内に配置して加熱する構成として、説明したが、これに限定されることはなく、図１１に示すように、アルミニウム合金部材３０１（ヒートシンク３１、ヒートシンク本体１１０）と金属部材３０２（金属層１３、金属部材層１１７）とを固相拡散接合する際に通電加熱法を適用してもよい。 In the metal layer / heat sink joining step S05 of the first embodiment, the metal layer 13 (Cu layer 13B) and the heat sink 31 are laminated, placed in a vacuum heating furnace in a state of being pressurized in the lamination direction, and heated. In the heat sink main body / metal member layer joining step S102 of the second embodiment, the heat sink main body 110 and the metal plate 127 to be the metal member layer 117 are stacked and pressurized in the stacking direction (pressure 5 to 35 kgf / Although described as a configuration in which it is placed in a vacuum heating furnace and heated in a state of cm 2 (0.49 to 3.43 MPa), the present invention is not limited to this, and as shown in FIG. When the member 301 (the heat sink 31, the heat sink body 110) and the metal member 302 (the metal layer 13, the metal member layer 117) are solid-phase diffusion bonded, an electric heating method is used. It may be.
　通電加熱を行う場合には、図１１に示すように、アルミニウム合金部材３０１と金属部材３０２とを積層し、これらの積層体を、カーボン板３１１，３１１を介して一対の電極３１２、３１２によって積層方向に加圧するとともに、アルミニウム合金部材３０１及び金属部材３０２に対して通電を行う。すると、ジュール熱によってカーボン板３１１，３１１及びアルミニウム合金部材３０１と金属部材３０２が加熱され、アルミニウム合金部材３０１と金属部材３０２とが固相拡散接合される。 In the case of conducting current heating, as shown in FIG. 11, an aluminum alloy member 301 and a metal member 302 are laminated, and these laminated bodies are laminated by a pair of electrodes 312 and 312 via carbon plates 311 and 311. While pressing in the direction, the aluminum alloy member 301 and the metal member 302 are energized. Then, the carbon plates 311 and 311 and the aluminum alloy member 301 and the metal member 302 are heated by Joule heat, and the aluminum alloy member 301 and the metal member 302 are solid-phase diffusion bonded.
　上述の通電加熱法においては、アルミニウム合金部材３０１及び金属部材３０２が直接通電加熱されることから、昇温速度を例えば３０～１００℃／ｍｉｎと比較的速くすることができ、短時間で固相拡散接合を行うことができる。これにより、接合面の酸化の影響が小さく、例えば大気雰囲気でも接合することが可能となる。また、アルミニウム合金部材３０１及び金属部材３０２の抵抗値や比熱によっては、これらアルミニウム合金部材３０１及び金属部材３０２に温度差が生じた状態で接合することも可能となり、熱膨張の差を小さくし、熱応力の低減を図ることもできる。 In the energization heating method described above, since the aluminum alloy member 301 and the metal member 302 are directly energized and heated, the rate of temperature increase can be made relatively fast, for example, 30 to 100 ° C./min, and the solid phase can be obtained in a short time. Diffusion bonding can be performed. Thereby, the influence of the oxidation of the bonding surface is small, and for example, bonding can be performed even in an air atmosphere. Further, depending on the resistance value and specific heat of the aluminum alloy member 301 and the metal member 302, it is possible to join the aluminum alloy member 301 and the metal member 302 in a state where a temperature difference is generated, thereby reducing the difference in thermal expansion, Thermal stress can also be reduced.
　ここで、上述の通電加熱法においては、一対の電極３１２，３１２による加圧荷重は、３０ｋｇｆ／ｃｍ２以上１００ｋｇｆ／ｃｍ２以下（２．９４ＭＰａ以上９．８１ＭＰａ以下）の範囲内とすることが好ましい。上記加圧荷重は、５０ｋｇｆ／ｃｍ２以上８０ｋｇｆ／ｃｍ２以下（４．９０ＭＰａ以上７．８５ＭＰａ以下）とすることがより好ましいが、これに限定されることはない。
　また、通電加熱法を適用する場合には、アルミニウム合金部材３０１及び金属部材３０２の表面粗さは、算術平均粗さＲａで０．３μｍ以上０．６μｍ以下、または、最大高さＲｚで１．３μｍ以上２．３μｍ以下の範囲内とすることが好ましい。通常の固相拡散接合では、接合面の表面粗さは小さいことが好ましいが、通電加熱法の場合には、接合面の表面粗さが小さすぎると、界面接触抵抗が低下し、接合界面を局所的に加熱することが困難となるため、上述の範囲内とすることが好ましい。 Here, in the electric heating method described above, the pressure load applied by the pair of electrodes 312 and 312 is set to be within a range of 30 kgf / cm 2 to 100 kgf / cm 2 (2.94 MPa to 9.81 MPa). preferable. The pressure load is more preferably 50 kgf / cm 2 or more and 80 kgf / cm 2 or less (4.90 MPa or more and 7.85 MPa or less), but is not limited thereto.
Further, when applying the electric heating method, the surface roughness of the aluminum alloy member 301 and the metal member 302 is 0.3 μm or more and 0.6 μm or less in terms of arithmetic average roughness Ra, or 1. It is preferable to be in the range of 3 μm or more and 2.3 μm or less. In normal solid phase diffusion bonding, it is preferable that the surface roughness of the bonding surface is small, but in the case of the electric heating method, if the surface roughness of the bonding surface is too small, the interface contact resistance decreases, and the bonding interface Since it becomes difficult to heat locally, it is preferable to be within the above range.
　なお、第一の実施形態の金属層／ヒートシンク接合工程Ｓ０５に上述の通電加熱法を用いることも可能であるが、その場合、セラミックス基板１１が絶縁体であるため、例えば、カーボンからなる冶具等でカーボン板３１１，３１１を短絡する必要がある。接合条件は、上述したアルミニウム部材３０１と銅部材３０２の接合と同様である。
　また、金属層１３（Ｃｕ層１３Ｂ）とヒートシンク３１の表面粗さについては、上述したアルミニウム部材３０１及び銅部材３０２の場合と同様である。 In addition, although it is also possible to use the above-mentioned electric heating method for the metal layer / heat sink bonding step S05 of the first embodiment, in this case, since the ceramic substrate 11 is an insulator, for example, a jig made of carbon, etc. Therefore, it is necessary to short-circuit the carbon plates 311 and 311. The joining conditions are the same as the joining of the aluminum member 301 and the copper member 302 described above.
The surface roughness of the metal layer 13 (Cu layer 13B) and the heat sink 31 is the same as that of the aluminum member 301 and the copper member 302 described above.
　以下に、本発明の効果を確認すべく行った確認実験の結果について説明する。 Hereinafter, the results of a confirmation experiment conducted to confirm the effect of the present invention will be described.
（試験片の作製）
　表１に示すアルミニウム合金板（５０ｍｍ×５０ｍｍ、厚さ５ｍｍ）の一方の面を表１記載のチル層の厚さになるまで研削し、その面に表１に示す金属板（４０ｍｍ×４０ｍｍ、厚さは表１参照）を、上述の実施形態に記載した方法によって固相拡散接合した。
　本発明例１－５及び比較例１－３においては、アルミニウム合金板と金属板とを積層方向に１５ｋｇｆ／ｃｍ２（１．４７ＭＰａ）の荷重で押圧し、真空加熱炉で５００℃、１８０ｍｉｎの条件で固相拡散接合を実施した。
　本発明例６－１０においては、アルミニウム合金板と金属板とを図１１に示す通電加熱法によって固相拡散接合した。なお、電極による加圧荷重を１５ｋｇｆ／ｃｍ２（１．４７ＭＰａ）とし、加熱温度（銅板温度）を５１０℃、加熱温度での保持時間を５ｍｉｎとし、昇温速度を８０℃／ｍｉｎとした。また、接合雰囲気を大気雰囲気とした。 (Preparation of test piece)
One surface of an aluminum alloy plate (50 mm × 50 mm, thickness 5 mm) shown in Table 1 was ground until the thickness of the chill layer described in Table 1 was reached, and a metal plate (40 mm × 40 mm, 40 mm × 40 mm, For the thickness, see Table 1) was solid phase diffusion bonded by the method described in the above embodiment.
In Invention Example 1-5 and Comparative Example 1-3, the aluminum alloy plate and the metal plate are pressed in the stacking direction with a load of 15 kgf / cm 2 (1.47 MPa), and are heated at 500 ° C. for 180 min in a vacuum heating furnace. Solid phase diffusion bonding was performed under the conditions.
In Inventive Example 6-10, an aluminum alloy plate and a metal plate were joined by solid phase diffusion bonding by the electric heating method shown in FIG. The pressure load by the electrode was 15 kgf / cm 2 (1.47 MPa), the heating temperature (copper plate temperature) was 510 ° C., the holding time at the heating temperature was 5 min, and the temperature rising rate was 80 ° C./min. The bonding atmosphere was an air atmosphere.
（接合前のアルミニウム合金板におけるチル層の厚さ）
　接合する前にアルミニウム板の観察を行い、接合面側に形成されたチル層の厚さを以下のように測定した。
　まず、ＥＰＭＡ（日本電子株式会社製ＪＸＡ―８５３０Ｆ）を用いて、アルミニウム板の表面を、視野３６０μｍ□、加速電圧１５ｋＶ、Ｓｉコンターレベル０～１０００の条件で、Ｓｉの面分析を実施し、図１２（ａ）に示すＳｉ分布像を得た。
　得られたＳｉ分布像を８ビットグレースケールに変換し、図１２（ｂ）に示すようなＳｉ分布像を得た。
　次に、Ｋａｐｕｒ－Ｓａｈｏｏ－Ｗｏｎｇ（Ｍａｘｉｍｕｍ　Ｅｎｔｒｏｐｙ）ｔｈｒｅｓｈｏｌｄｉｎｇ　ｍｒｔｈｏｄ（Ｋａｐｕｒ，ＪＮ；Ｓａｈｏｏ，ＰＫ；Ｗｏｎｇ，ＡＣＫ（１９８５）、“Ａ　Ｎｅｗ　Ｍｅｔｈｏｄ　ｆｏｒ　Ｇｒａｙ－Ｌｅｖｅｌ　Ｐｉｃｔｕｒｅ　Ｔｈｒｅｓｈｏｌｄｉｎｇ　Ｕｓｉｎｇ　ｔｈｅ　Ｅｎｔｒｏｐｙ　ｏｆ　ｔｈｅ　Ｈｉｓｔｏｇｒａｍ”，Ｇｒａｐｈｉｃａｌ　Ｍｏｄｅｌｓ　ａｎｄ　Ｉｍａｇｅ　Ｐｒｏｃｅｓｓｉｎｇ　２９（３）：２７３－２８５参照）に基づいて、図１２（ｃ）に示すように、Ｓｉ分布像を２値化した。
　次に、図１２（ｄ）に示すように、２値化した画像からＳｉ相の輪郭を楕円近似により抽出した。
　Ｓｉ相の輪郭を抽出した画像を基に、楕円近似から求められる長径及び短径を用いて下記式からアスペクト比及び結晶粒径を算出した。
　アスペクト比＝長径／短径
　結晶粒径＝長径
　そして、３６０μｍ２の面積内において、アスペクト比が２．５以下かつ結晶粒径が１５μｍ以下の条件（以下、単に条件と表す）を満たす粒子の個数と前記条件を満たさない粒子の個数を求め、条件を満たす個数／条件を満たさない個数を求めた。
　上述した測定方法にて、アルミニウム板表面から板内部に向かって１０μｍ毎に測定を行い、条件を満たす個数／条件を満たさない個数が３以上の部分をチル層と定義し、厚さを求めた。
　評価結果を表１に示す。 (Thickness of chill layer in aluminum alloy plate before joining)
Before joining, the aluminum plate was observed, and the thickness of the chill layer formed on the joining surface side was measured as follows.
First, using an EPMA (JXA-8530F manufactured by JEOL Ltd.), the surface of the aluminum plate was subjected to Si surface analysis under the conditions of a visual field of 360 μm □, an acceleration voltage of 15 kV, and an Si contour level of 0 to 1000. The Si distribution image shown in 12 (a) was obtained.
The obtained Si distribution image was converted to an 8-bit gray scale to obtain a Si distribution image as shown in FIG.
Next, Kapur-Saho-Wong (Maximum Entropy) thresholding mrthod (Kapur, JN; Saho, PK; Wong, ACK (1985), “A New Method for Gray-Let-Let ' and Image Processing 29 (3): 273-285), the Si distribution image was binarized as shown in FIG. 12 (c).
Next, as shown in FIG. 12 (d), the outline of the Si phase was extracted from the binarized image by elliptic approximation.
Based on the image obtained by extracting the outline of the Si phase, the aspect ratio and the crystal grain size were calculated from the following formulas using the major axis and minor axis obtained from elliptical approximation.
Aspect ratio = major axis / minor axis Crystal grain size = major axis The number of particles satisfying the condition that the aspect ratio is 2.5 or less and the crystal grain size is 15 μm or less (hereinafter simply referred to as conditions) within the area of 360 μm 2. The number of particles that do not satisfy the above conditions was determined, and the number of particles that did not satisfy the conditions / conditions was determined.
Using the measurement method described above, measurement was performed every 10 μm from the surface of the aluminum plate toward the inside of the plate, the number of conditions satisfying the number / number of conditions not satisfying the condition of 3 or more was defined as the chill layer, and the thickness was determined. .
The evaluation results are shown in Table 1.
（接合後のアルミニウム合金板と金属板との接合界面におけるチル層の厚さ）
　固相拡散接合されたアルミニウム合金板と金属板との接合体の断面観察を行い、接合界面に形成されたチル層の厚さを以下のように測定した。
　接合体の接合界面をＥＰＭＡ（日本電子株式会社製ＪＸＡ―８５３０Ｆ）を用いて、観察し、アルミニウム合金板内部へと成長したＡｌと金属板の金属元素（Ｃｕ、Ｎｉ、Ａｇ）の金属間化合物の厚さを求め、接合前のチル層の厚さから、前記Ａｌと金属板の金属元素（Ｃｕ、Ｎｉ、Ａｇ）の金属間化合物の厚さを引いた厚さを、接合後のチル層の厚さとした。
なお、金属間化合物の厚さは、接合界面を接合体の厚さ方向にライン分析し、Ａｌの濃度が、金属板として銅を用いた場合は６５ａｔ％～７０ａｔ％、金属板としてニッケルを用いた場合は５５ａｔ％～８０ａｔ％、金属板として銀を用いた場合は２０ａｔ％～４５ａｔ％の領域を金属間化合物とみなし、その厚さを測定した。
　評価結果を表１に示す。 (Thickness of the chill layer at the bonded interface between the aluminum alloy plate and the metal plate after bonding)
The cross-section of the joined body of the aluminum alloy plate and the metal plate bonded by solid phase diffusion was observed, and the thickness of the chill layer formed at the joint interface was measured as follows.
The joint interface of the joined body was observed using EPMA (JXA-8530F manufactured by JEOL Ltd.), and the intermetallic compound of Al and the metal elements (Cu, Ni, Ag) of the metal plate grown inside the aluminum alloy plate The thickness of the chill layer after joining is obtained by subtracting the thickness of the intermetallic compound of Al and the metal elements (Cu, Ni, Ag) of the metal plate from the thickness of the chill layer before joining. And the thickness.
The thickness of the intermetallic compound was determined by line analysis of the bonding interface in the thickness direction of the bonded body. The Al concentration was 65 at% to 70 at% when copper was used as the metal plate, and nickel was used as the metal plate. The thickness was measured by regarding the region of 55 at% to 80 at% as the intermetallic compound when silver was used as the metal plate and the range of 20 at 45 to 45 at% as the metal plate.
The evaluation results are shown in Table 1.
（ヒートサイクル試験）
　次に、このようにして製造された接合体において、ヒートサイクル試験を実施した。冷熱衝撃試験機エスペック社製ＴＳＢ－５１を使用し、試験片（ヒートシンク付パワーモジュール）に対して、液相（フロリナート）で、－４０℃で５分、１５０℃で５分のヒートサイクルを４０００回実施した。
　そして、ヒートサイクル試験前における接合体の積層方向の熱抵抗、及び、ヒートサイクル試験後における接合体の積層方向の熱抵抗を以下のようにして評価した。 (Heat cycle test)
Next, a heat cycle test was performed on the joined body thus manufactured. Use TSB-51, a thermal shock tester manufactured by Espec Corp., and test specimen (power module with heat sink) in a liquid phase (Fluorinert) at -40 ° C for 5 minutes and 150 ° C for 5 minutes for a heat cycle of 4000 Conducted once.
Then, the thermal resistance in the stacking direction of the joined body before the heat cycle test and the thermal resistance in the stacking direction of the joined body after the heat cycle test were evaluated as follows.
（熱抵抗の測定）
　ヒータチップ（１３ｍｍ×１０ｍｍ×０．２５ｍｍ）を金属板の表面に半田付けし、アルミニウム合金板を冷却器にろう付け接合した。次に、ヒータチップを１００Ｗの電力で加熱し、熱電対を用いてヒータチップの温度を実測した。また、冷却器を流通する冷却媒体（エチレングリコール：水＝９：１）の温度を実測した。そして、ヒータチップの温度と冷却媒体の温度差を電力で割った値を熱抵抗とした。
　なお、チル層を形成せずにアルミニウム合金板と銅板とを固相拡散接合した比較例１のヒートサイクル前の熱抵抗を基準として１とし、この比較例１との比率で熱抵抗を評価した。評価結果を表１に示す。 (Measurement of thermal resistance)
A heater chip (13 mm × 10 mm × 0.25 mm) was soldered to the surface of the metal plate, and the aluminum alloy plate was brazed to the 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 the cooling medium (ethylene glycol: water = 9: 1) flowing through the cooler was measured. And the value which divided the temperature difference of a heater chip | tip and the temperature of a cooling medium with electric power was made into thermal resistance.
In addition, the thermal resistance before the heat cycle of Comparative Example 1 in which the aluminum alloy plate and the copper plate were solid-phase diffusion bonded without forming the chill layer was set to 1, and the thermal resistance was evaluated at a ratio with Comparative Example 1. . The evaluation results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　チル層を形成せずにアルミニウム合金板と金属板（銅板）とを固相拡散接合した比較例１においては、本発明例と比べ熱抵抗が大きくなっていることが確認された。また、金属板としてニッケルを用いた比較例２と本発明例４及び９を比べると、比較例２の熱抵抗が大きくなっていることが確認された。同様に金属板として銀を用いた比較例３と本発明例５及び１０を比べると比較例３の熱抵抗が大きくなっていることが確認された。これらは、カーケンダルボイドが形成されたためと推測される。 In Comparative Example 1 in which an aluminum alloy plate and a metal plate (copper plate) were solid-phase diffusion bonded without forming a chill layer, it was confirmed that the thermal resistance was higher than that of the present invention. Moreover, when Comparative Example 2 using nickel as the metal plate was compared with Invention Examples 4 and 9, it was confirmed that the thermal resistance of Comparative Example 2 was increased. Similarly, when Comparative Example 3 using silver as a metal plate was compared with Invention Examples 5 and 10, it was confirmed that the thermal resistance of Comparative Example 3 was increased. These are presumed to be due to the formation of Kirkendall void.
　これに対して、接合前のチル層の厚さ及び接合後のチル層の厚さを本発明の範囲内とさせた本発明例においては、比較例に比べて熱抵抗が小さくなっていることが確認された。適正な厚さのチル層を介在させることにより、金属板を構成する金属元素の拡散が抑制され、カーケンダルボイドの発生が抑制されたためと推測される。
　また、通電加熱法を適用した本発明例６－１０においては、大気中で接合してもアルミニウム合金板と金属板とが良好に接合されていた。 On the other hand, in the present invention example in which the thickness of the chill layer before joining and the thickness of the chill layer after joining are within the scope of the present invention, the thermal resistance is smaller than that of the comparative example. Was confirmed. It is presumed that by interposing a chill layer having an appropriate thickness, diffusion of metal elements constituting the metal plate is suppressed, and generation of Kirkendall void is suppressed.
Further, in Invention Examples 6-10 to which the current heating method was applied, the aluminum alloy plate and the metal plate were satisfactorily joined even when they were joined in the air.
　以上の結果から、本発明によれば、比較的固相線温度の低いアルミニウム合金からなるアルミニウム合金部材と、銅、ニッケル、又は銀からなる金属部材とが良好に接合され、積層方向の熱抵抗が低い接合体を得ることが可能であることが確認された。 From the above results, 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 bonded, and the thermal resistance in the stacking direction It was confirmed that it is possible to obtain a bonded body having a low A.
　本発明によれば、比較的固相線温度の低いアルミニウム合金からなるアルミニウム合金部材と、銅、ニッケル、又は銀からなる金属部材とが良好に接合され、積層方向の熱抵抗が低い接合体、この接合体を備えたヒートシンク付パワーモジュール用基板及びヒートシンク、及び、接合体の製造方法、ヒートシンク付パワーモジュール用基板の製造方法、ヒートシンクの製造方法を提供することが可能となる。 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 well bonded, and a bonded body having a low thermal resistance in the stacking direction, It becomes possible to provide a power module substrate with a heat sink and a heat sink, and a manufacturing method of the bonded body, a manufacturing method of the power module substrate with a heat sink, and a manufacturing method of the heat sink.
　１０、２１０　パワーモジュール用基板
　１１　セラミックス基板
　１３，２１３　金属層
　１３Ｂ　Ｃｕ層（金属部材）
　３１　ヒートシンク（アルミニウム合金部材）
　３５　チル層
　１０１　ヒートシンク
　１１０　ヒートシンク本体（アルミニウム合金部材）
　１１７　金属部材層
　１３５　チル層  10, 210 Power module substrate 11 Ceramic substrate 13,213 Metal layer 13B Cu layer (metal member)
31 Heat sink (aluminum alloy member)
35 Chill layer 101 Heat sink 110 Heat sink body (aluminum alloy member)
117 Metal member layer 135 Chill layer

Claims (9)

  1. 　銅、ニッケル、又は銀からなる金属部材と、固相線温度が前記金属部材を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金からなるアルミニウム合金部材と、が接合されてなる接合体であって、
    　前記アルミニウム合金部材と前記金属部材とが固相拡散接合されており、
    　前記アルミニウム合金部材のうち前記金属部材との接合界面側には、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、
    　前記チル層の厚さが５０μｍ以上とされていることを特徴とする接合体。     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 constituting the metal member and aluminum. A joined body,
    The aluminum alloy member and the metal member are solid phase diffusion bonded,
    A chill layer in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed is formed on the bonding interface side of the aluminum alloy member with the metal member.
    A joined body, wherein the thickness of the chill layer is 50 μm or more.
  2. 　絶縁層と、この絶縁層の一方の面に形成された回路層と、前記絶縁層の他方の面に形成された金属層と、この金属層の前記絶縁層とは反対側の面に配置されたヒートシンクと、を備えたヒートシンク付パワーモジュール用基板であって、
    　前記金属層のうち前記ヒートシンクとの接合面は、銅、ニッケル、又は銀で構成され、
    　前記ヒートシンクのうち前記金属層との接合面は、固相線温度が前記金属層の前記接合面を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成され、
    　前記ヒートシンクと前記金属層とが固相拡散接合されており、
    　前記ヒートシンクのうち前記金属層との接合界面側には、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、
    　前記チル層の厚さが５０μｍ以上とされていることを特徴とするヒートシンク付パワーモジュール用基板。     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 surface of the metal layer opposite to the insulating layer. Heat sink, and a power module substrate with a heat sink,
    Of the metal layer, the bonding surface with the heat sink is made of copper, nickel, or silver,
    The joining surface of the heat sink with the metal layer is made of an aluminum alloy whose solidus temperature is less than the eutectic temperature of the metal element and aluminum constituting the joining surface of the metal layer,
    The heat sink and the metal layer are solid phase diffusion bonded,
    A chill layer in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed is formed on a side of a joint interface with the metal layer in the heat sink,
    A power module substrate with a heat sink, wherein the chill layer has a thickness of 50 μm or more.
  3. 　ヒートシンク本体と、前記金属部材層と、を備えたヒートシンクであって、
    　前記金属部材層は、銅、ニッケル、又は銀からなり、
    　前記ヒートシンク本体は、固相線温度が前記金属部材層を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成され、
    　前記ヒートシンク本体のうち前記金属部材層との接合界面側には、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層が形成されており、
    　前記チル層の厚さが５０μｍ以上とされていることを特徴とするヒートシンク。     A heat sink comprising a 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 whose solidus temperature is less than the eutectic temperature of the metal element and aluminum constituting the metal member layer,
    A chill layer in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed is formed on the heat sink body on the side of the bonding interface with the metal member layer.
    A heat sink, wherein a thickness of the chill layer is 50 μm or more.
  4. 　銅、ニッケル、又は銀からなる金属部材と、固相線温度が前記金属部材を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金からなるアルミニウム合金部材と、が接合されてなる接合体の製造方法であって、
    　接合前の前記アルミニウム合金部材において、前記金属部材との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上とし、
    　このアルミニウム合金部材と前記金属部材とを固相拡散接合することを特徴とする接合体の製造方法。     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 constituting the metal member and aluminum. A method for manufacturing a joined body, comprising:
    In the aluminum alloy member before bonding, a chill layer in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed is formed on the bonding surface side with the metal member. The thickness of this chill layer is 80 μm or more,
    A method of manufacturing a joined body, comprising solid-phase diffusion bonding the aluminum alloy member and the metal member.
  5. 　前記アルミニウム合金部材と前記金属部材とを積層し、積層方向に加圧しながら通電して加熱することにより、前記アルミニウム合金部材と前記金属部材とを固相拡散接合することを特徴とする請求項４に記載の接合体の製造方法。 5. The aluminum alloy member and the metal member are laminated, and the aluminum alloy member and the metal member are bonded by solid phase diffusion bonding by energizing and heating while pressing in the laminating direction. The manufacturing method of the conjugate | zygote of description.
  6. 　絶縁層と、この絶縁層の一方の面に形成された回路層と、前記絶縁層の他方の面に形成された金属層と、この金属層の前記絶縁層とは反対側の面に配置されたヒートシンクと、を備えたヒートシンク付パワーモジュール用基板の製造方法であって、
    　前記金属層のうち前記ヒートシンクとの接合面は、銅、ニッケル、又は銀で構成され、
    　前記ヒートシンクのうち前記金属層との接合面は、固相線温度が前記金属層の前記接合面を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成されており、
    　接合前の前記ヒートシンクにおいて、前記金属層との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上とし、
    　このヒートシンクと前記金属層とを固相拡散接合することを特徴とするヒートシンク付パワーモジュール用基板の製造方法。     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 surface of the metal layer opposite to the insulating layer. A method of manufacturing a power module substrate with a heat sink comprising:
    Of the metal layer, the bonding surface with the heat sink is made of copper, nickel, or silver,
    The joining surface of the heat sink with the metal layer is made of an aluminum alloy whose solidus temperature is less than the eutectic temperature of the metal element and aluminum constituting the joining surface of the metal layer,
    In the heat sink before bonding, a chill layer in which an Si phase having a crystal grain aspect ratio of 2.5 or less and a crystal grain size of 15 μm or less is dispersed is formed on the bonding surface side with the metal layer. The layer thickness is 80 μm or more,
    A method of manufacturing a power module substrate with a heat sink, wherein the heat sink and the metal layer are bonded by solid phase diffusion bonding.
  7. 　前記ヒートシンクと前記金属層とを積層し、積層方向に加圧しながら通電して加熱することにより、前記ヒートシンクと前記金属層とを固相拡散接合することを特徴とする請求項６に記載のヒートシンク付パワーモジュール用基板の製造方法。 The heat sink according to claim 6, wherein the heat sink and the metal layer are laminated, and the heat sink and the metal layer are solid-phase diffusion bonded by applying current and heating while pressing in the laminating direction. Method for manufacturing a power module substrate.
  8. 　ヒートシンク本体と、前記金属部材層と、を備えたヒートシンクの製造方法であって、
    　前記金属部材層は、銅、ニッケル、又は銀からなり、
    　前記ヒートシンク本体は、固相線温度が前記金属部材層を構成する金属元素とアルミニウムとの共晶温度未満とされたアルミニウム合金で構成されており、
    　接合前の前記ヒートシンク本体において、前記金属部材層との接合面側に、結晶粒のアスペクト比が２．５以下で結晶粒径が１５μｍ以下であるＳｉ相が分散したチル層を形成するとともに、このチル層の厚さを８０μｍ以上とし、
    　このヒートシンク本体と前記金属部材層とを固相拡散接合することを特徴とするヒートシンクの製造方法。     A heat sink manufacturing method comprising a 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 whose solidus temperature is less than the eutectic temperature of the metal element and aluminum constituting the metal member layer,
    In the heat sink body before bonding, on the bonding surface side with the metal member layer is formed a chill layer in which an Si phase in which the crystal grain aspect ratio is 2.5 or less and the crystal grain size is 15 μm or less is dispersed, The thickness of this chill layer is 80 μm or more,
    A method of manufacturing a heat sink, comprising solid-phase diffusion bonding the heat sink body and the metal member layer.
  9. 　前記ヒートシンク本体と前記金属部材層とを積層し、積層方向に加圧しながら通電して加熱することにより、前記ヒートシンク本体と前記金属部材層とを固相拡散接合することを特徴とする請求項８に記載のヒートシンクの製造方法。 9. The heat sink body and the metal member layer are laminated, and the heat sink body and the metal member layer are solid-phase diffusion bonded by heating with energization while pressing in the stacking direction. The manufacturing method of the heat sink as described in 2.
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