JP2016160492A - Manufacturing method of heat radiator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a heat radiator having excellent heat radiation performance by making solderability on an outside surface of a heat exchanger.SOLUTION: An aluminum alloy material 15 constituting a heat exchanger 10 contains Mn:0.7 to 1.2 mass%, Fe:0.02 to 0.7 mass% and Si:0.05 to 0.4 mass% and has area percentage of an Al-Fe-based intermetallic compound of 0.3 to 1.5% and average particle diameter of crystal of 50 to 500 μm and a component 20 with heat radiation is face jointed to an outer surface of the heat exchanger 10 constituted by the aluminum alloy material 15 by using an Al-Si-based alloy brazing material 33 containing 0.02 to 0.7 mass% of Fe and 0.05 to 2.0 mass% of Mg.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of manufacturing a heat radiating device in which components that generate heat are favorably surface-bonded to the outer surface of a heat exchanger and related technology.

  Patent Document 1 discloses that in a heat dissipation device in which an electronic element mounting substrate in which an aluminum circuit layer is bonded to an insulating substrate is brazed to a heat sink, thermal resistance is reduced and good heat dissipation is obtained. Moreover, in the said heat radiating device, in order to relieve the stress which generate | occur | produces between an insulated substrate and a heat sink, the stress relaxation layer which has a some through-hole as a stress absorption space is interposed. In the heat dissipation device having such a laminated structure, the stress relaxation layer serves as a heat exhaust path for the electronic element mounted on the electronic element mounting substrate.

  In Patent Document 2, a sacrificial corrosion layer is laminated on one surface of an aluminum alloy core material containing Mn, Cu, Si, and Fe as a tube material for an automotive heat exchanger, and a brazing material is disposed on the other surface. A laminated brazing clad material is described. The clad material is bent so that the sacrificial corrosion layer is on the inside, and the inner surface of the tube is brazed with corrugated fins on the outer surface to prevent corrosion.

JP 2006-294699 A JP 2000-202680 A

  Since the corrugated fins are brazed to the outer surface of the tube described in Patent Document 2, the joint is linear and the joint area is small. On the other hand, in the heat radiating device of Patent Document 1, the outer surface of the heat sink is bonded to the stress relaxation layer with a large area. The through hole of the stress relaxation layer is necessary as a stress absorption space under a cooling cycle, and is also necessary as a space for discharging the oxide film during brazing, but reduces the thermal resistance when exhausting heat to the heat sink, In order to improve the design freedom of the heat dissipation device, it is required to reduce the area of the through hole as much as possible. For this reason, the heat sink and the stress relaxation layer are brazed in a wide area. When brazing a large area well, it is necessary to enhance the wettability of the brazing further than the linear brazing and promote the discharge of the oxide film.

  In addition, when water is used as the working fluid for the heat sink, high corrosion resistance is also required on the inner surface.

  However, the brazing clad material described in Patent Document 2 is used for joining corrugated fins in a linear shape, and in order to braze a large area, the material having better wettability of the brazing material. is necessary.

  In view of the background art described above, an object of the present invention is to provide a method for manufacturing a heat dissipation device having excellent heat dissipation performance by improving the brazing property on the outer surface of a heat exchanger.

  That is, this invention has the structure as described in following [1]-[10].

[1] The aluminum alloy material constituting the heat exchanger contains Mn: 0.7 to 1.2% by mass, Fe: 0.02 to 0.7% by mass, and Si: 0.05 to 0.4% by mass. And the area ratio of the Al—Fe-based intermetallic compound is 0.3 to 1.5%, the average grain size of the crystals is 50 to 500 μm,
Al-Si containing 0.02 to 0.7% by mass of Fe and 0.05 to 2.0% by mass of Mg on the outer surface of the heat exchanger made of the aluminum alloy material. A method for manufacturing a heat radiating device, characterized in that surface bonding is performed using a brazing alloy brazing material.

  [2] The component that generates heat is an electronic element mounting board in which an aluminum circuit layer for mounting an electronic element is brazed to one surface of an insulating substrate, and is opposite to the aluminum circuit layer of the electronic element mounting board. 2. The method for manufacturing a heat radiating device according to item 1, wherein the side surface is surface-bonded to the outer surface of the heat exchanger.

  [3] The aluminum alloy material constituting the heat exchanger is further Cu: 0.2-0.7 mass%, Mg: 0.05-0.4 mass%, Zr: 0.05-0.4 mass %, V: 0.05-0.4 mass%, and Ti: 0.05-0.4 mass% The manufacturing method of the heat radiator of the preceding clause 1 or 2 containing at least 1 sort (s).

  [4] Among the preceding items 1 to 3, wherein the Al—Si based alloy brazing material contains at least one of Bi: 0.03 to 1.5 mass% and Sr: 0.005 to 0.2 mass%. The manufacturing method of the thermal radiation apparatus of any one of these.

  [5] The aluminum alloy material constituting the heat exchanger is an alloy material subjected to homogenization treatment at 600 to 640 ° C. for 6 to 24 hours, according to any one of the preceding items 1 to 4. Manufacturing method of heat dissipation device.

  [6] The heat dissipation device according to any one of 1 to 5 above, wherein the aluminum alloy material constituting the heat exchanger is an alloy material annealed at 350 to 450 ° C. for 1 to 12 hours. Manufacturing method.

  [7] The preceding item in which a stress relaxation layer is interposed between the electronic element mounting substrate and the heat exchanger, and the stress relaxation layer is surface-bonded to the outer surface of the heat exchanger using the Al—Si based alloy brazing. The manufacturing method of the thermal radiation apparatus of any one of 2-6.

  [8] The method for manufacturing a heat dissipation device according to any one of items 1 to 7, wherein the working fluid circulating in the hollow portion of the heat exchanger is water.

[9] The heat exchanger contains Mn: 0.7 to 1.2% by mass, Fe: 0.02 to 0.7% by mass and Si: 0.05 to 0.4% by mass, and Al— The area ratio of the Fe-based intermetallic compound is 0.3 to 1.5%, and is composed of an aluminum alloy material having an average crystal grain size of 50 to 500 μm.
On the outer surface of the heat exchanger composed of the aluminum alloy material, a part with heat generation is Al—Si containing 0.02 to 0.7 mass% Fe and 0.05 to 2.0 mass% Mg. A heat radiating device characterized by being surface-bonded by a system alloy brazing material.

  [10] The component that generates heat is an electronic element mounting board in which an aluminum circuit layer for mounting an electronic element is brazed to one surface of an insulating substrate, and is opposite to the aluminum circuit layer of the electronic element mounting board. 10. The heat dissipation device according to item 9, wherein a side surface is surface-bonded to the outer surface of the heat exchanger.

  According to the invention described in [1], the chemical composition and the metal structure of the aluminum alloy material constituting the heat exchanger are defined, and a part that generates heat on the outer surface of the heat exchanger is further changed to Al containing Fe and Mg. -Because the brazing material is joined using the Si-based alloy brazing material, the brazing material is sufficiently wetted and spread, especially in vacuum brazing, the oxide film is removed by destroying the oxide film while Mg evaporates, and surface bonding is excellent. can do. Since the heat exchanger and heat-generating components can be surface-bonded well, manufacturing a heat dissipation device with excellent heat dissipation performance with low heat resistance when the heat generated by the components is exhausted to the heat exchanger it can. Moreover, since the aluminum alloy material which comprises a heat exchanger is excellent in corrosion resistance, the heat radiating device excellent in corrosion resistance can be manufactured.

  According to invention of [2], said effect can be acquired in manufacture of the thermal radiation apparatus which carries out surface bonding of the board | substrate for electronic element mounting to the outer surface of a heat exchanger.

  According to the invention described in [3], since one or more elements of Cu, Mg, Zr, V, and Ti are added to the aluminum alloy material, higher brazing and corrosion resistance can be obtained. .

  According to the invention described in [4], since Sr is added to the Al—Si based alloy brazing material containing Fe and Bi, higher brazing properties can be obtained.

  According to the invention described in [5], by performing a predetermined homogenization treatment on the aluminum alloy material constituting the heat exchanger, the area ratio of the Al—Fe intermetallic compound is 0.3 to 1.5%. The average crystal grain size can be controlled in the range of 50 to 500 μm.

  According to the invention described in [6], the aluminum alloy material constituting the heat exchanger is subjected to predetermined annealing, whereby the area ratio of the Al—Fe intermetallic compound is 0.3 to 1.5%, The average particle size can be controlled in the range of 50 to 500 μm.

  According to the invention described in [7], the above-described effect can be obtained in the manufacture of a heat radiating device in which the heat exchanger and the electronic element mounting substrate are surface-bonded via the stress relaxation layer.

  According to the invention described in [8], the above-described effect can be obtained in the manufacture of a heat dissipation device used in a severe corrosive environment using water as a working fluid of a heat exchanger.

  According to the invention described in [9], in the heat radiating device, the chemical composition and the metal structure of the aluminum alloy material constituting the heat exchanger are defined, and further, the parts that generate heat on the outer surface of the heat exchanger are Fe and Mg. The brazing material is sufficiently wetted and spread, especially in vacuum brazing, and the oxide film is removed by destroying the oxide film while Mg evaporates. The surface is well bonded. Such a heat dissipating device has excellent heat dissipating performance with little heat resistance when the heat generated by the components is exhausted to the heat exchanger. Moreover, since the aluminum alloy material which comprises a heat exchanger is excellent in corrosion resistance, it is excellent also in corrosion resistance.

  According to the invention described in [10], the above effect can be obtained in the heat dissipation device in which the electronic element mounting substrate is surface-bonded to the outer surface of the heat exchanger.

It is sectional drawing which shows one Embodiment of the thermal radiation apparatus manufactured with the method of this invention. It is sectional drawing which shows other embodiment of the thermal radiation apparatus manufactured with the method of this invention. It is sectional drawing which shows other embodiment of the heat sink manufactured by the method of this invention.

[Structure of heat dissipation device]
FIG. 1 shows an embodiment of a heat radiating device manufactured by the method of the present invention, and a temporary assembly of a heat radiating device 1 in which a heat sink 10 and an electronic element mounting substrate 20 are stacked with a stress relaxation layer 30 interposed therebetween is configured. A cross section cut in the direction in which the members are stacked is shown.

  In the heat sink 10, a flat hollow portion formed by combining two dish-like members 11 having recesses 12 serves as a working fluid passage 13 for circulating a working fluid. 14 is interpolated. The dish-shaped member 11 is formed by pressing a flat clad material in which a brazing material 16 is laminated on one surface of a core material 15 so that the brazing material 16 is inside the recess 12, and is substantially from the opening periphery of the recess 12. The part extending in the horizontal direction is the peripheral edge 17 for bonding. The heat sink 10 has two plate-like members 11 arranged face-to-face so that the brazing material 16 is on the inside, the inner fin 14 is sandwiched between the recesses 12, and the joining peripheral edge portions 17 are in contact with each other. The inner fin 14 is temporarily assembled in contact with the inner wall of the passage 13.

  The electronic element mounting substrate 20 includes an insulating substrate 21, an aluminum circuit layer 22 superimposed on one surface of the insulating substrate 21, and an aluminum layer 23 superimposed on the other surface. These members 21, 22, and 23 are temporarily assembled with the brazing material foils 24 and 25 interposed therebetween.

  The electronic element mounting substrate 20 and the heat sink 10 are laminated via a stress relaxation layer 30. The stress relieving layer 30 is an aluminum clad material in which brazing materials 32 and 33 are laminated on both surfaces of a core material 31, and is a punching metal in which a plurality of circular through holes 34 are formed as a stress absorbing space after clad. In addition, the stress relaxation layer 30 used for the heat radiating device 1 of this invention is not limited to the thing with the through-hole 34, and the shape of stress absorption space is not limited.

  The heat dissipating device 1 is subjected to brazing heat for the temporary assembly all together, and all members are brazed. That is, in the brazing of the heat sink 10, the joining peripheral edge portion 17 is brazed by the brazing material 16 of the clad material constituting the dish-like member 11 to form the working fluid passage 13, and the wall surface of the working fluid passage 13. Inner fins 14 are brazed to each other. Each layer of the electronic element mounting substrate 20 is brazed, and the electronic element mounting substrate 20 is brazed to the outer surface of the heat sink 10 via the stress relaxation layer 30. Thereafter, an electronic element (not shown) is mounted on the aluminum circuit layer 22 and soldered. In the heat dissipation device 1 after brazing, the aluminum circuit layer 22 is thermally coupled to the heat sink 16 via the insulating substrate 21, the aluminum layer 23, and the stress relaxation layer 30, and the heat generated by the electronic elements is exhausted to the heat sink 10. .

  In the heat radiating device 1, the heat sink 10 corresponds to the heat exchanger according to the present invention, and the electronic element mounting board 20 corresponds to a component that similarly generates heat. The core material 15 of the clad material that is the material of the dish-like member 11 of the heat sink 10 corresponds to the aluminum alloy material constituting the heat exchanger in the present invention, and the heat sink 10 side of the clad material that is the material of the stress relaxation layer 30. The brazing material 33 corresponds to an Al—Si alloy brazing material containing Fe and Bi.

  On the inner surface of the heat sink 10, high corrosion resistance is required so that a sufficiently long life can be obtained even when water is used as a working fluid. On the outer surface, the stress relaxation layer 30 serves as a heat exhaust path to the heat sink 10, and a reduction in brazing area due to a brazing failure results in a decrease in heat dissipation performance. The relaxing layer 30 is required to be satisfactorily surface-bonded. In the brazing of the heat sink 10 and the stress relieving layer 30, good brazing is achieved by discharging the oxide film to the outer peripheral portion of the joint and the through hole 34 by wet spreading of the brazing material.

  The surface bonding in the present invention means bonding in which the short side of the bonding portion is 5 mm or more. The shape of the bonding portion is not limited, and a linear bonding portion having a width of 5 mm or more and a circular bonding portion having a diameter of 5 mm or more correspond to surface bonding. In the heat dissipation device 1, the joint between the heat sink 10 and the stress relaxation layer 30 is a surface joint, and the joint excluding the joint between the inner fin 14 and the wall surface of the working fluid passage 13 is also a surface joint.

  The method for manufacturing a heat dissipation device of the present invention defines an aluminum alloy material that constitutes a heat exchanger, and further defines a brazing material for surface-joining a part that generates heat on the outer surface of the heat exchanger. It has good corrosion resistance and good surface brazing on the outer surface of the heat exchanger.

[Aluminum alloy material constituting the heat exchanger]
The aluminum alloy material that constitutes the heat exchanger is based on the fact that the Al-Fe intermetallic compound in the aluminum alloy affects the corrosion resistance and brazing property, and the crystal diameter affects the brazing property. After defining the chemical composition, the amount of Al—Fe-based intermetallic compound in the metal structure is defined as the area ratio in an arbitrary cross section and the average crystal grain size. As described above, in the heat sink 10, the core material 15 of the clad material 11 serving as the outer surface of the heat sink corresponds to the aluminum alloy material.

  Below, the chemical composition and metal structure of an aluminum alloy material are explained in full detail.

  As the aluminum alloy material, an aluminum alloy containing a predetermined amount of Mn, Fe and Si is used. Further, Cu, Mg, Zr, V, and Ti can be recommended as optional additional elements of the aluminum alloy. Hereinafter, the contents of each element and the reasons for limiting the concentration range will be described in detail.

  Fe has a concentration of 0.02 to 0.7% by mass in order to control the area ratio of the Al—Fe-based intermetallic compound within the above range. If the Fe concentration is less than 0.05% by mass, the amount of Al—Fe-based intermetallic compound is small, so that the brazing property is lowered and it is uneconomical in terms of material purification. On the other hand, if it exceeds 0.5% by mass, the amount of Al—Fe-based intermetallic compound increases and the corrosion resistance decreases. A preferable Fe concentration is 0.1 to 0.45 mass%.

  Mn has a concentration of 0.7 to 1.2% by mass in order to control the amount of Al—Fe—Mn intermetallic compound. If the Mn concentration is less than 0.7% by mass, the amount of Al—Fe—Mn intermetallic compound decreases, and the above-mentioned area ratio of the intermetallic compound cannot be obtained, and the brazing property is lowered. On the other hand, if it exceeds 1.2 mass%, the amount of Al-Fe-Mn intermetallic compound increases and the corrosion resistance decreases. A preferable Mn concentration is 0.7 to 1.2% by mass.

  Si has a concentration of 0.05 to 0.4 mass% in order to control the amount of Al—Fe—Si intermetallic compound. If the Si concentration is less than 0.05% by mass, the amount of the Al—Fe—Si intermetallic compound decreases, and the area ratio of the intermetallic compound described above cannot be obtained, and the brazing property is lowered. On the other hand, when it exceeds 0.4 mass%, the amount of Al—Fe—Si intermetallic compounds increases and the corrosion resistance decreases. A preferable Si concentration is 0.1 to 0.3% by mass.

  Cu, Mg, Zr, V, and Ti are elements that affect the corrosion resistance, and the corrosion resistance can be improved by adding at least one of them. When these elements are added, the Cu concentration in the alloy is 0.2 to 0.7 mass%, the Mg concentration is 0.05 to 0.4 mass%, the Zr concentration is 0.05 to 0.4 mass%, The V concentration is 0.05 to 0.4% by mass and the Ti concentration is 0.05 to 0.4% by mass. If the concentration of each element is less than the lower limit, the effect of improving corrosion resistance cannot be obtained, and addition exceeding the upper limit is uneconomical. Particularly preferable concentrations of each element are Cu: 0.25 to 0.65 mass%, Mg: 0.1 to 0.35 mass%, Zr: 0.1 to 0.3 mass%, V: 0.1 to 0.1 mass%. 0.3 mass%, Ti: 0.1-0.3 mass%.

  In the chemical composition of the aluminum alloy constituting the core material 15, the balance is Al and inevitable impurities.

  In the metal structure of the aluminum alloy material, the area ratio of the Al—Fe-based intermetallic compound is 0.3 to 1.5%, and the average crystal grain size is 50 to 500 μm.

  In the present invention, “Al—Fe intermetallic compound” means all intermetallic compounds containing Al and Fe, and the Al—Fe intermetallic compound formed in the aluminum alloy constituting the aluminum alloy material is Al -Fe, Al-Fe-Si, Al-Fe-Mn, Al-Fe-Si-Mn, etc., and all of these Al-Fe-based intermetallic compounds are subject to area ratio regulation. When the area ratio of the Al—Fe-based intermetallic compound is less than 0.3%, the wetting and spreading of the brazing material becomes worse and the brazing property is lowered. On the other hand, if the Al-Fe intermetallic compound exceeds 1.5%, the corrosion resistance is deteriorated. A preferable area ratio of the Al—Fe-based intermetallic compound is 0.3 to 1%.

  On the other hand, if the average crystal grain size is less than 50 μm, the crystal grain boundaries increase and the brazing material erodes the core material, so that the fluidity of the brazing material is deteriorated. On the other hand, when the average particle size exceeds 500 μm, the crystal grain boundary decreases, so the amount of Al—Fe intermetallic compound present at the crystal grain boundary decreases, and as a result, the fluidity of the brazing material deteriorates. Therefore, when the average grain size of the crystal is less than 50 μm and more than 500 μm, the brazing property is lowered. A preferable range of the average grain size of the crystals is 50 to 300 μm.

  In this embodiment, the aluminum alloy material is used as the core material 15 and the clad material 11 in which the brazing material 16 is integrated is used for manufacturing the heat sink 10.

  The brazing material 16 is not limited, and for example, an Al—Si alloy brazing material can be used. The preferable Si concentration in the Al—Si based alloy brazing material is 6 to 12% by mass. The brazing method may be flux brazing or vacuum brazing. In the case of vacuum brazing, an Al-Si-Mg based alloy having an Mg concentration of 0.5 to 2% by mass can be recommended. It is preferable to use a brazing material having an Mg concentration of 0.1% by mass or less. In any brazing material, the balance is Al and inevitable impurities. Moreover, in order to improve brazing property, it is preferable to add at least one of Bi and Sr to these brazing materials. When adding these elements, it is preferable to add such that the Bi concentration in the Al-Si alloy is 0.03 to 1.5 mass% and the Sr concentration is 0.005 to 0.2 mass%. If the concentration of each element is less than the lower limit value, the effect of improving brazability cannot be obtained, and adding a large amount exceeding the upper limit value is uneconomical. Particularly preferable concentrations of each element are Bi: 0.05 to 1.0% by mass and Sr: 0.01 to 0.1% by mass.

  The present invention is not limited to the use of a clad material as the material of the heat sink 10, and the present invention includes a case where the bare material having the chemical composition and metal structure of the core material 15 described above is used.

  In the present invention, the structure of the heat exchanger is not limited to the illustrated example, but the aluminum alloy material for the heat exchanger used in the present invention has high corrosion resistance, so that water is circulated as a working fluid. Suitable for manufacturing heat exchangers. Further, the use of the heat exchanger is not limited, and examples thereof include an electronic element cooling heat exchanger, an evaporator, a condenser, a heater core, an oil cooler, and an intercooler. In addition, the shape of the heat exchanger, the forming method from the flat plate-shaped aluminum alloy material or the clad material is not limited.

[Method for producing aluminum alloy material]
The clad material is produced by laminating the core material and the brazing material having the above-described chemical composition, hot rolling and clad, and if necessary, further rolling to a required thickness. In this step, the core material before rolling, that is, the aluminum alloy material in the present invention is subjected to predetermined homogenization treatment to control the amount of intermetallic compound and the crystal grain size, and the area of the Al—Fe intermetallic compound in the metal structure. The rate and the average grain size of the crystals can be within the scope of the present invention.

  The homogenization treatment of the core material is performed by holding at 600 to 640 ° C. for 6 to 24 hours. If it is less than 600 ° C. or less than 6 hours, the desired metal structure cannot be obtained, and good brazing and corrosion resistance cannot be obtained. On the other hand, if a treatment at 640 ° C. or 24 hours is performed, a desired metal structure can be obtained. Therefore, treatment at a higher temperature or longer time is uneconomical in terms of energy. The preferable temperature of the homogenization treatment is 600 to 630 ° C., and the preferred treatment time is 8 to 20 hours.

  It is also preferable to perform annealing at 350 to 450 ° C. for 1 to 12 hours. By performing annealing under the above conditions, it is possible to form a metal structure with higher brazability and corrosion resistance by ensuring the formation of the desired metal structure. A particularly preferable annealing temperature is 360 to 430 ° C., and a particularly preferable annealing time is 2 to 10 hours. A preferable processing time for the annealing is after the homogenized material is processed into the thickness of the heat exchanger material. In the case of the clad material, it is preferable to perform annealing after clad rolling to a predetermined thickness in the homogenization treatment.

  Moreover, when using a bare material as a heat exchanger material, the material which performed the said homogenization process is processed into predetermined thickness, and it anneals on said conditions after that. By performing these heat treatments on the bare material as well, the amount of intermetallic compounds and the crystal grain size are controlled, and the area ratio of Al—Fe intermetallic compounds and the average grain size of crystals in the metal structure are within the scope of the present invention. can do.

[Al-Si alloy brazing material]
The Al—Si based brazing material used for the surface bonding on the outer surface of the heat sink 10 described above is incorporated in the temporary assembly of the heat dissipation device 1 as the brazing material 33 of the clad material constituting the stress relaxation layer 30.

  The brazing material 33 is an Al—Si alloy brazing material containing 0.02 to 0.7 mass% Fe and 0.05 to 2.0 mass% Mg. In this Al-Si alloy brazing material containing Fe and Mg, Fe is an element that forms an Al-Fe intermetallic compound at the joint interface and promotes the flowability of the brazing to improve the surface brazing property. . When the Fe concentration in the brazing material is less than 0.02% by mass, there is no effect of promoting the flowability of the brazing, and addition exceeding 0.7% by mass is uneconomical. A particularly preferable Fe concentration is 0.05 to 0.6% by mass. Mg is an element that improves the brazing property by removing the oxide film by destroying the oxide film on the surface of the member to be brazed while evaporating in vacuum brazing while improving the fluidity of the brazing material. When the Mg concentration in the brazing material is less than 0.05% by mass, the above effect is small. On the other hand, if the Mg concentration exceeds 2.0% by mass, an oxide film such as MgO grows too much and the brazing property is lowered. A preferable Mg concentration is 0.3 to 1.7% by mass. The preferable Si concentration is 6 to 12% by mass. The balance of the brazing material is Al and inevitable impurities.

  The brazing method may be flux brazing or vacuum brazing.

  Moreover, in order to improve brazing property, it is preferable to add at least one of Bi and Sr to the brazing material. When adding these elements, it is preferable to add such that the Bi concentration in the Al-Si alloy is 0.03 to 1.5 mass% and the Sr concentration is 0.005 to 0.2 mass%. If the concentration of each element is less than the lower limit value, the effect of improving brazability cannot be obtained, and adding a large amount exceeding the upper limit value is uneconomical. Particularly preferable concentrations of each element are Bi: 0.05 to 1.0% by mass and Sr: 0.01 to 0.1% by mass.

[Electronic element mounting substrate and stress relaxation layer]
The electronic element mounting substrate only needs to have the aluminum circuit layer 22 bonded to at least one surface of the insulating substrate 21, and the other surface may have the aluminum layer 23 bonded as shown in FIG. Further, like the electronic element mounting substrate 26 of FIG. 3, the insulating substrate 21 may be directly joined to the stress relaxation layers 30 and 37 without the aluminum layer on the other surface side. Furthermore, the case where the insulating substrate 21 is directly bonded to the heat sink 10 (not shown) is also included in the present invention.

  In the electronic element mounting substrate, examples of the material constituting the insulating substrate 21 include ceramics such as aluminum nitride, aluminum oxide, silicon nitride, zirconium oxide, and silicon carbide. These ceramics are recommended not only because of their excellent electrical insulation, but also because they have good thermal conductivity and excellent heat dissipation. For the aluminum circuit layer 22 and the aluminum layer 23, high-purity aluminum having good conductivity and heat conductivity can be recommended.

  The stress relaxation layer is preferably made of a 1000 series or 3000 series aluminum alloy having good heat conductivity. The shape preferably has a through hole that becomes a stress absorbing space and serves as a discharge location of the oxide film during brazing, but the present invention does not exclude a stress relaxation layer having no through hole.

  In addition, the present invention is not limited to the electronic element mounting substrate, but the method of the present invention can be applied to any component that generates heat that can be brazed.

[Supply of brazing material on the outer surface of the heat exchanger]
Brazing on the outer surface of the heat sink is surface bonding regardless of whether the counterpart material is an electronic element mounting substrate or a stress relaxation layer, and the above-described Al—Si based alloy brazing material containing Fe and Mg is used. The method for supplying the brazing material is not limited, and the brazing material may be clad and integrated, or may be supplied as a brazing material foil or brazing material powder. Further, the heat sink and the mating material can be brazed with a brazing sheet in which a brazing material is clad on both sides.

  In each of the heat dissipating devices 1, 2, and 3 in FIGS. 1 to 3, the mating material of the heat sink 10 is a stress relaxation layer, and the brazing material supplying method is different. In the heat radiating device 1 of FIG. 1, the material for the stress relaxation layer is the clad material 30 in which the core material 31 is clad with an Al—Si alloy brazing material 33 containing Fe and Mg, and the core material 31 is substantially after brazing. It becomes a stress relaxation layer. 2 is an example in which a bare material is used as the stress relaxation layer 36 and a brazing material foil 38 made of an Al—Si based alloy containing Fe and Mg is assembled. The heat radiating device 3 in FIG. 3 also uses a stress relaxation layer 37 made of a bare material, but a double-sided brazing sheet 39 is used for joining to the heat sink 10. In the double-sided brazing sheet 39, a through hole 39a of the same size is formed at a position overlapping the through hole 34 of the stress relaxation layer 37, and the brazing material 39b on the heat sink 10 side contains an Fe—Mg alloy. It is a brazing material.

  According to the method for manufacturing a heat radiating device of the present invention, it is possible to satisfactorily surface-join components that generate heat on the outer surface of the heat exchanger, and the manufactured heat radiating device is heat generated when heat generated by the components is exhausted to the heat exchanger. It has low resistance and has excellent heat dissipation performance. Moreover, since the aluminum alloy material which comprises a heat exchanger is excellent in corrosion resistance, the application significance as a material of the heat exchanger used in a severer corrosive environment is large. One example of such a heat exchanger is a heat sink 10 that is incorporated in the heat dissipating devices 1, 2, and 3 shown in FIGS. When the electronic element mounting substrate 20 is surface-bonded to the outer surface directly or via the stress relaxation layer 30 and the working fluid is water, high heat resistance is required not only on the outer surface but also on the inner surface. is there.

A heat sink and a stress relaxation layer were produced using the clad material, and a heat radiating device 1 referred to FIG. 1 was produced together with other members.
[Examples 1 to 12, Comparative Examples 1 to 5]
A two-layer clad material as a material of the dish-like member 11 of the heat sink 10 shown in FIG. 1 was produced. In Examples 1 to 12 and Comparative Examples 1 to 5, the chemical composition of the aluminum alloy constituting the core material 15 and the brazing material 16 of the clad material is as shown in Table 1, and the production conditions of the clad material are common.

  The aluminum alloy lump for the core material is homogenized at 620 ° C. for 12 hours, and is hot rolled and clad with the aluminum alloy lump for the brazing material. The total thickness is 0.8 mm. A 7% double-layer clad material was used, and the clad material was annealed at 400 ° C. for 4 hours.

  The produced cladding material 11 was examined for the area ratio of the Al—Fe-based intermetallic compound and the average grain size of the crystals, and the results are shown in Table 1. The produced clad material was formed into a dish-like member 11 shown in FIG. 1 by press molding.

  As for the material of the stress relaxation layer 30, the core material 31 is made of 3003 aluminum alloy, the brazing material 32 on the electronic device mounting substrate 20 side is made of Al-10 mass% Si-1 mass% Mg alloy, and the heat sink 10 side brazing material 33 is represented. 1 is a three-layer clad material made of an aluminum alloy having the chemical composition shown in FIG. The three-layer clad material has a total thickness of 1 mm, and the clad rate of the brazing materials 32 and 33 is 4% per side. The stress relaxation layer 30 was produced by cutting the three-layer clad material into 28 mm × 28 mm and further cutting to form 12 circular through holes 34 having a diameter of 2 mm.

  Moreover, the other member in the thermal radiation apparatus 1 is as follows.

  The corrugated inner fin 14 is formed by bending a 3000 series alloy plate having a thickness of 1.2 mm. The insulating substrate 21 is a 30 mm × 30 mm × 0.6 mm thick flat plate made of aluminum nitride. The aluminum circuit layer 22 and the aluminum layer 23 are 0.6 mm thick flat plates made of high-purity aluminum having a purity of 99.99% or more. The brazing foils 24 and 25 are made of an Al-10 mass% Si-1 mass% Mg alloy, and the foil thickness is 30 μm.

Furthermore, each member was temporarily assembled on the laminate having the structure shown in FIG. 1, and the temporary assembly was vacuum brazed in a vacuum of 7 × 10 ⁻⁴ Pa at 600 ° C. for 20 minutes. The brazed heat dissipation device 1 was tested and evaluated for surface brazing and corrosion resistance by the following methods. The evaluation results are shown in Table 1.
(Face brazing)
The bonding interface between the heat sink 10 and the stress relaxation layer 30 is detected with an ultrasonic flaw detector and the area bonded to the area (28 × 28−12 × π mm ² ) excluding the through hole 34 of the stress relaxation layer 30 is obtained. The proportion was examined. A bonding area ratio of 97% or more was evaluated as “◯”, 95% or more and less than 97% as “Δ”, and 95% or less as “×”.
(Corrosion resistance)
OY water (Cl ⁻ : 195 ppm, SO ₄ ²⁻ : 60 ppm, Fe ³⁺ : 30 ppm, Cu ²⁺ : 1 ppm) was used as the working fluid of the heat sink 10, and one cycle of 80 ° C. × 8 hours and room temperature × 16 hours was used. A cycle (480 hours) corrosion acceleration test was conducted.

The corrosion depth on the inner surface of the heat sink 10 after the corrosion acceleration test was measured, and the corrosion depth was evaluated as “◯” when less than 300 μm, “Δ” when 300 μm or more and less than 600 μm, and “×” when 600 μm or more.
[Examples 13 to 15]
Using the same core material and brazing material as in Example 2, the two-layer clad material was produced by changing the homogenization condition of the core material and the annealing condition after clad. The homogenization conditions and annealing conditions for each example are as shown in Table 2.

The area ratio of the Al—Fe-based intermetallic compound and the average grain size of the crystals were examined for the produced two-layer clad material. Further, a dish-like member 11 for the heat sink 10 was formed with this two-layer clad material. Except for the dish-like member 11, the heat radiating device 1 is temporarily assembled using the same members as in Example 2, and the temporary assembly is vacuum brazed at 600 ° C. for 20 minutes in a vacuum of 7 × 10 ⁻⁴ Pa. Brazing and corrosion resistance were tested and evaluated in the same manner as in Example 1 and the like. The evaluation results are shown in Table 2.

  As shown in Tables 1 and 2, the heat exchanger using the predetermined heat sink material and the brazing material for brazing the outer surface of the heat sink achieves good brazing even in large area brazing and has excellent corrosion resistance. ing.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for manufacturing a heat dissipation device that brazes an electronic element mounting substrate and a heat exchanger over a large area on the outer surface of a heat exchanger.

1, 2, 3 ... Radiating device 10 ... Heat sink (heat exchanger)
11 ... Plate-like member 15 ... Core material (aluminum alloy material)
20, 26 ... Electronic device mounting substrate (components that generate heat)
DESCRIPTION OF SYMBOLS 21 ... Insulating substrate 22 ... Aluminum circuit layer 30, 36, 37 ... Stress relaxation layer 34 ... Through-hole 33, 38, 39b ... Brazing material (Al-Si type alloy brazing material containing Fe and Mg)

Claims (10)

The aluminum alloy material constituting the heat exchanger contains Mn: 0.7 to 1.2% by mass, Fe: 0.02 to 0.7% by mass and Si: 0.05 to 0.4% by mass, And the area ratio of the Al—Fe-based intermetallic compound is 0.3 to 1.5%, the average grain size of the crystals is 50 to 500 μm,
Al-Si containing 0.02 to 0.7% by mass of Fe and 0.05 to 2.0% by mass of Mg on the outer surface of the heat exchanger made of the aluminum alloy material. A method for manufacturing a heat radiating device, characterized in that surface bonding is performed using a brazing alloy brazing material.   The component that generates heat is an electronic element mounting substrate in which an aluminum circuit layer on which an electronic element is mounted is brazed on one surface of an insulating substrate, and the surface on the opposite side of the aluminum circuit layer of the electronic element mounting substrate The manufacturing method of the heat radiating device according to claim 1, wherein surface bonding is performed on the outer surface of the heat exchanger.   The aluminum alloy material constituting the heat exchanger is further Cu: 0.2-0.7 mass%, Mg: 0.05-0.4 mass%, Zr: 0.05-0.4 mass%, V The manufacturing method of the thermal radiation apparatus of Claim 1 or 2 containing at least 1 sort (s): 0.05-0.4 mass% and Ti: 0.05-0.4 mass%.   The Al-Si alloy brazing material contains at least one of Bi: 0.03 to 1.5 mass% and Sr: 0.005 to 0.2 mass%. A method for manufacturing the heat dissipation device according to claim 1.   The heat dissipation device according to any one of claims 1 to 4, wherein the aluminum alloy material constituting the heat exchanger is an alloy material subjected to a homogenization treatment at 600 to 640 ° C for 6 to 24 hours. Manufacturing method.   The aluminum alloy material that constitutes the heat exchanger is an alloy material that has been annealed at 350 to 450 ° C for 1 to 12 hours, and manufacturing the heat dissipation device according to any one of claims 1 to 5. Method.   A stress relaxation layer is interposed between the electronic element mounting substrate and the heat exchanger, and the stress relaxation layer is surface bonded to the outer surface of the heat exchanger using the Al-Si alloy brazing. 6. A method for manufacturing a heat dissipation device according to claim 1.   The manufacturing method of the heat radiating device according to any one of claims 1 to 7, wherein the working fluid circulating through the hollow portion of the heat exchanger is water. The heat exchanger contains Mn: 0.7 to 1.2% by mass, Fe: 0.02 to 0.7% by mass and Si: 0.05 to 0.4% by mass, and an Al—Fe-based metal The area ratio of the intermetallic compound is 0.3 to 1.5%, and is composed of an aluminum alloy material having an average crystal grain size of 50 to 500 μm,
On the outer surface of the heat exchanger composed of the aluminum alloy material, a part with heat generation is Al—Si containing 0.02 to 0.7 mass% Fe and 0.05 to 2.0 mass% Mg. A heat radiating device characterized by being surface-bonded by a system alloy brazing material. The component that generates heat is an electronic element mounting substrate in which an aluminum circuit layer on which an electronic element is mounted is brazed on one surface of an insulating substrate, and the surface on the opposite side of the aluminum circuit layer of the electronic element mounting substrate The heat radiating device according to claim 9, wherein the surface is joined to an outer surface of the heat exchanger.