JP6518460B2 - Method of manufacturing heat dissipation device - Google Patents

Description

  The present invention relates to a method of manufacturing a heat dissipation device in which components with heat generation are well surface-joined to the outer surface of a heat exchanger, and related techniques.

  It is disclosed in Patent Document 1 that the heat resistance is reduced in the heat dissipation device in which the electronic element mounting substrate in which the aluminum circuit layer is joined to the insulating substrate is brazed to the heat sink. Further, in the heat dissipation device, a stress relaxation layer having a plurality of through holes is interposed as a stress absorption space in order to relieve the stress generated between the insulating substrate and the heat sink. In the heat dissipation device having such a laminated structure, the stress relieving layer serves as a heat removal path of 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 of a heat exchanger for automobiles, and a brazing material is formed on the other surface. A laminated brazing clad material is described. The clad material is bent so that the sacrificial corrosion layer is inside, and the inner surface of the tube brazed with a corrugated fin on the outer surface is protected.

JP, 2006-294699, A JP 2000-202680 A

  Since it is a corrugated fin that is brazed to the outer surface of the tube described in Patent Document 2, the junction is linear and the junction area is small. On the other hand, in the heat dissipation device of Patent Document 1, the outer surface of the heat sink is joined to the stress relieving layer over a wide area. The through holes of the stress relieving layer are necessary as a stress absorbing space under thermal cycle, and also as a space for discharging an oxide film at the time of brazing, but the thermal resistance at the time of exhausting heat to the heat sink is reduced. 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 large area. In the case of good brazing of a large area, it is necessary to further enhance the wettability and spreadability of the braze to promote the discharge of the oxide film more than the linear brazing.

  Moreover, when using water as a working fluid of a heat sink, high corrosion resistance is calculated | required also on the inner surface.

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

  An object of the present invention is, in view of the background art described above, to provide a method of manufacturing a heat dissipation device having excellent heat dissipation performance by improving the brazability of the outer surface of the heat exchanger.

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

[1] The aluminum alloy material constituting the heat exchanger comprises 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 intermetallic compound is 0.3 to 1.5%, and the average particle size of the crystals is 50 to 500 μm,
On the outer surface of the heat exchanger made of the aluminum alloy material, parts with heat generation are contained with 0.02 to 0.7% by mass of Fe and 0.3% by mass or more and 1.5% by mass or less of Bi A method of manufacturing a heat dissipating device characterized by surface bonding using an Al-Si based alloy brazing material.

  [2] The component accompanied by heat generation is an electronic device mounting substrate to which an aluminum circuit layer mounting the electronic device is brazed to one surface of the insulating substrate, and the opposite of the aluminum circuit layer of the electronic device mounting substrate The method of manufacturing a heat dissipation device according to claim 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 further contains Cu: 0.2 to 0.7% by mass, Mg: 0.05 to 0.4% by mass, and Zr: 0.05 to 0.4% 3. The method for producing a heat dissipation device according to the above 1 or 2, which contains at least one of%, V: 0.05 to 0.4% by mass, and Ti: 0.05 to 0.4% by mass.

  [4] The method for manufacturing a heat dissipation device according to any one of the aforementioned Items 1 to 3, wherein the Al—Si alloy brazing material contains Sr: 0.005 to 0.2 mass%.

  [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. Method of manufacturing a heat dissipation device.

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

  [7] The preceding item wherein a stress relieving layer is interposed between the electronic element mounting substrate and the heat exchanger, and the stress relieving layer is surface-joined to the outer surface of the heat exchanger using the Al-Si based alloy brazing. The manufacturing method of the heat radiating device of any one of 2-6.

  [8] The method for manufacturing a heat dissipation device as recited in any one of the aforementioned 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— It is composed of an aluminum alloy material in which the area ratio of the Fe-based intermetallic compound is 0.3 to 1.5%, and the average particle size of crystals is 50 to 500 μm,
Parts with heat generation contain 0.02 to 0.7% by mass of Fe and 0.3% by mass or more and 1.5% by mass or less of Bi on the outer surface of the heat exchanger made of the aluminum alloy material. A heat dissipation device characterized in that surface bonding is performed by using an Al-Si based alloy brazing material.

  [10] The component with heat generation is an electronic device mounting substrate to which an aluminum circuit layer for mounting the electronic device is brazed to one surface of the insulating substrate, and the opposite of the aluminum circuit layer of the electronic device mounting substrate The heat dissipation device according to the above 9, wherein the side surface is surface-bonded to the outer surface of the heat exchanger.

  According to the invention described in [1], the chemical composition and metallographic structure of the aluminum alloy material that constitutes the heat exchanger are defined, and further, the part with heat generation on the outer surface of the heat exchanger is made of Al containing Fe and Bi. -Since bonding is performed using a Si-based alloy brazing material, the brazing material can be sufficiently wet-spreaded to achieve good surface bonding. Since the heat exchanger and parts with heat generation can be surface-joined favorably, a heat dissipation device having excellent heat dissipation performance with little heat resistance when exhausting the heat generated by the parts to the heat exchanger is manufactured. it can. Moreover, since the aluminum alloy material which comprises a heat exchanger is excellent in corrosion resistance, it can manufacture the thermal radiation apparatus excellent in corrosion resistance.

  According to the invention described in [2], the above effect can be obtained in the manufacture of a heat dissipation device in which the electronic element mounting substrate is surface-bonded to the outer surface of the 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 brazability 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 brazability can be obtained.

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

  According to the invention described in [6], by subjecting the aluminum alloy material constituting the heat exchanger to a predetermined annealing, the area ratio of the Al-Fe based intermetallic compound is 0.3 to 1.5%, and the crystal is It can be controlled in the range of 50 to 500 μm in average particle diameter.

  According to the invention described in [7], the above effect can be obtained in the manufacture of the heat dissipation 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 effect can be obtained in the manufacture of a heat dissipation device used in a severe corrosive environment where water is used as a working fluid of a heat exchanger.

  According to the invention described in [9], in the heat dissipation device, the chemical composition and metallographic structure of the aluminum alloy material constituting the heat exchanger are defined, and further, the parts with heat generation on the outer surface of the heat exchanger are Fe and Bi. Since it is joined using an Al-Si based alloy brazing material containing Al, the brazing material sufficiently wets and spreads and is well surface-joined. Such a heat dissipation device has excellent heat dissipation 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.

FIG. 2 is a cross-sectional view of an embodiment of a heat dissipation device manufactured by the method of the present invention. FIG. 6 is a cross-sectional view showing another embodiment of a heat dissipation device manufactured by the method of the present invention. FIG. 6 is a cross-sectional view showing still another embodiment of the heat dissipation device manufactured by the method of the present invention.

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

  The heat sink 10 has a flat hollow portion formed by combining two plate-like members 11 having a recess 12 as a working fluid passage 13 for circulating the working fluid, and the working fluid passage 13 has a corrugated inner fin 14 is interpolated. The plate-like member 11 is formed by pressing a flat clad material in which the brazing material 16 is laminated on one surface of the core material 15 so that the brazing material 16 is on the inside of the recess 12. The portion extending in the horizontal direction is the bonding peripheral edge portion 17. The heat sink 10 arranges the two plate-like members 11 so as to face each other so that the brazing material 16 is on the inner side, sandwiches the inner fins 14 with the recesses 12 and abuts the bonding peripheral edge portions 17 with each other. The inner fins 14 are temporarily assembled in a state of being 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 stacked on one surface of the insulating substrate 21, and an aluminum layer 23 stacked on the other surface. These members 21, 22, 23 are temporarily assembled with the brazing foil 24, 25 interposed therebetween.

  The electronic element mounting substrate 20 and the heat sink 10 are laminated via a stress relieving layer 30. The stress relieving layer 30 is an aluminum clad material in which brazing materials 32, 33 are laminated on both sides 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 cladding. The stress relieving layer 30 used in the heat dissipation device 1 of the present invention is not limited to the one having the through holes 34, and the shape of the stress absorbing space is also not limited.

  The heat radiating device 1 is brazed collectively to the temporary assembly, and the entire assembly is brazed. That is, in brazing of the heat sink 10, the bonding peripheral edge portion 17 is brazed by the brazing material 16 of the clad material constituting the plate-like member 11 to form the working fluid passage 13 and the wall surface of the working fluid passage 13 The inner fins 14 are brazed to the Further, the respective layers of the electronic element mounting substrate 20 are 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 element is dissipated to the heat sink 10 .

  In the heat dissipation device 1, the heat sink 10 corresponds to the heat exchanger in the present invention, and the electronic element mounting substrate 20 corresponds to a component that also generates heat. Further, the core material 15 of the clad material which is the material of the plate-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 which is the material of the stress relaxation layer 30. The brazing filler metal 33 corresponds to an Al-Si based alloy brazing filler metal also containing Fe and Bi.

  The inner surface of the heat sink 10 is required to have high corrosion resistance so that a sufficiently long life can be obtained even when water is used as the working fluid. In addition, on the outer surface, the stress relieving layer 30 is a heat exhaust path to the heat sink 10, and the decrease in the brazing area due to the brazing defect results in a decrease in the heat radiation performance. The relaxation layer 30 is required to be well surface-bonded. In brazing of the heat sink 10 and the stress relieving layer 30, good brazing is achieved by the oxide film being discharged to the outer peripheral portion of the joint and the through hole 34 by the wetting and spreading of the brazing material.

  The face 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 relieving layer 30 is surface joint, and the joint except the joint between the inner fin 14 and the wall surface of the working fluid passage 13 is also surface joint.

  The method of manufacturing a heat dissipation device according to the present invention defines an aluminum alloy material that constitutes a heat exchanger, and further defines a brazing material that surface-joins parts with heat generation on the outer surface of the heat exchanger. Good corrosion resistance and good surface brazing on the outer surface of the heat exchanger are obtained.

[Aluminum alloy material of heat exchanger]
With regard to the aluminum alloy material constituting the heat exchanger, attention is paid to the fact that the Al-Fe based intermetallic compound in the aluminum alloy affects the corrosion resistance and the brazeability, and the crystal diameter influences the brazeability, In the metallographic structure, the amount of Al—Fe-based intermetallic compounds is defined as the area ratio in any cross section and the average grain size of crystals. As described above, in the heat sink 10, the core material 15 of the clad material 11 to be the heat sink outer surface corresponds to the aluminum alloy material.

  The chemical composition and metal structure of the aluminum alloy material will be described in detail below.

  The aluminum alloy material is an aluminum alloy containing predetermined amounts of Mn, Fe and Si. In addition, Cu, Mg, Zr, V, and Ti can be recommended as optional additional elements of the aluminum alloy. The significance of containing each element and the reason for limiting the concentration range will be described in detail below.

  In order to control the area ratio of an Al-Fe-based intermetallic compound within the above range, the concentration of Fe is set to 0.02 to 0.7% by mass. If the Fe concentration is less than 0.05% by mass, the amount of Al-Fe based intermetallic compounds is small, so 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 compounds increases and the corrosion resistance is lowered. The preferred Fe concentration is 0.1 to 0.45 mass%.

  In order to control the amount of Al-Fe-Mn-based intermetallic compounds, the concentration of Mn is set to 0.7 to 1.2% by mass. If the Mn concentration is less than 0.7% by mass, the amount of the Al-Fe-Mn based intermetallic compound decreases, the area ratio of the above-described intermetallic compound can not be obtained, and the brazing property is reduced. On the other hand, when it exceeds 1.2% by mass, the amount of Al-Fe-Mn based intermetallic compound increases and the corrosion resistance is lowered. The preferred Mn concentration is 0.7 to 1.2% by mass.

  The concentration of Si is set to 0.05 to 0.4% by mass in order to control the amount of the Al-Fe-Si intermetallic compound. If the Si concentration is less than 0.05% by mass, the amount of the Al-Fe-Si based intermetallic compound decreases, the area ratio of the above-described intermetallic compound can not be obtained, and the brazing property is reduced. On the other hand, when it exceeds 0.4% by mass, the amount of Al-Fe-Si based intermetallic compound increases and the corrosion resistance is lowered. The preferred 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% by mass, the Mg concentration is 0.05 to 0.4% by mass, and the Zr concentration is 0.05 to 0.4% by 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 value, the effect of improving the corrosion resistance can not be obtained, and the addition exceeding the upper limit value 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 0.3 mass%, Ti: 0.1 to 0.3 mass%.

  In the chemical composition of the aluminum alloy constituting the core material 15, the balance is Al and unavoidable 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 particle size of the crystals is 50 to 500 μm.

  In the present invention, "Al-Fe-based intermetallic compound" means all intermetallic compounds containing Al and Fe, and Al-Fe-based intermetallic compounds formed in the aluminum alloy constituting the aluminum alloy material are Al -Fe, Al-Fe-Si, Al-Fe-Mn, Al-Fe-Si-Mn, etc., and all of these Al-Fe-based intermetallic compounds are targets of area ratio definition. If the area ratio of the Al-Fe-based intermetallic compound is less than 0.3%, the wetting and spreading of the brazing material worsens and the brazing property decreases. On the other hand, if the Al-Fe based intermetallic compound exceeds 1.5%, the corrosion resistance is deteriorated. The area ratio of a preferable Al-Fe-based intermetallic compound is 0.3 to 1%.

  In addition, if the average grain size of the crystals is less than 50 μm, grain boundaries increase and the brazing material corrodes the core material, so that the flowability of the brazing material deteriorates. On the other hand, when the average particle size exceeds 500 μm, the grain boundaries are reduced, so the amount of Al-Fe based intermetallic compounds present in the grain boundaries is also reduced, and as a result, the fluidity of the brazing material is deteriorated. Therefore, if the average grain size of the crystals is less than 50 μm and more than 500 μm, the brazing property is reduced. The preferred range of the average particle size of the crystals is 50 to 300 μm.

  Further, in the present 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 based alloy brazing material can be used. The preferred Si concentration in the Al—Si alloy brazing material is 6 to 12 mass%. Also, the brazing method may be flux brazing or vacuum brazing, and in the case of vacuum brazing, an Al-Si-Mg based alloy having a Mg concentration of 0.5 to 2% by mass can be recommended, and in the case of flux brazing It is preferable to use a brazing material having an Mg concentration of 0.1% by mass or less. The balance in any of the brazing materials is Al and unavoidable impurities. Moreover, in order to improve the brazeability, 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 so that Bi density | concentration in Al-Si type alloy may become 0.03-1.5 mass%, and Sr density | concentration may become 0.005-0.2 mass%. If it is less than the lower limit of the concentration of each element, the effect of improving the brazability can not be obtained, and a large amount addition exceeding the upper limit is uneconomical. Particularly preferable concentrations of the respective elements 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, but is also included in the present invention when a bear material having the above-described chemical composition and metal structure of the core material 15 is used.

  In the present invention, the structure of the heat exchanger is not limited to that of the illustrated example, but the aluminum alloy material for heat exchanger used in the present invention has high corrosion resistance, so water is circulated as the working fluid. Suitable for the production of heat exchangers. Further, the application of the heat exchanger is not limited, and an electronic element cooling heat exchanger, an evaporator, a condenser, a heater core, an oil cooler, an intercooler, and the like can be exemplified. Further, the shape of the heat exchanger, the method of forming from the flat aluminum alloy material and the clad material are not limited.

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

  The homogenization treatment of the core material is carried out by maintaining at 600 to 640 ° C. for 6 to 24 hours. If it is less than 600 ° C. or less than 6 hours, the desired metallographic structure can not be obtained, and good brazability and corrosion resistance can not be obtained. On the other hand, since the desired metallographic structure can be obtained by performing the treatment at 640 ° C. or for 24 hours, the treatment at a high temperature or for a long time beyond that is uneconomical in energy. The preferred temperature of the homogenization treatment is 600-630 ° C., and the preferred treatment time is 8-20 hours.

  It is also preferable to perform annealing at 350 to 450 ° C. for 1 to 12 hours. By annealing under the above conditions, the desired formation of the metallographic structure can be made more secure, and a metallographic structure that can provide higher brazability and corrosion resistance can be formed. The particularly preferred annealing temperature is 360 to 430 ° C., and the particularly preferred annealing time is 2 to 10 hours. The preferred treatment time of the annealing is after processing the homogenized material to 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 bear material as a material for heat exchangers, the material which gave the said homogenization process is processed into a predetermined | prescribed thickness, and annealing is performed on said conditions after that. Also in the case of the bare material, the amount of the intermetallic compound and the crystal grain size are controlled by performing these heat treatments, and in the metal structure, the area ratio of the Al-Fe intermetallic compound and the average grain size of the crystals are within the scope of the present invention can do.

[Al-Si based alloy brazing material]
The Al—Si based alloy brazing material used for 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 filler metal 33 is an Al-Si based alloy brazing filler material containing 0.02 to 0.7% by mass of Fe and 0.3 to 1.5% by mass or less of Bi. In this Al-Si alloy brazing material containing Fe and Bi, Fe is an element that forms an Al-Fe intermetallic compound at the bonding interface to promote the flowability of the brazing material and to improve the surface brazing property. . If the Fe concentration in the brazing material is less than 0.02% by mass, there is no effect to promote the flowability of the braze, and the addition exceeding 0.7% by mass is uneconomical. Particularly preferable Fe concentration is 0.05 to 0.6% by mass. Bi is an element that improves the brazing property, and the Bi concentration is more than 0.3% by mass and 1.5% by mass or less. Addition of a large amount of Bi concentration exceeding 1.5% by mass is uneconomical. Particularly preferable Bi concentration is 0.05 to 1.0% by mass. Moreover, preferable Si concentration is 6-12 mass%. Also, the brazing method may be flux brazing or vacuum brazing, and in the case of vacuum brazing, an Al-Si-Mg based alloy having a Mg concentration of 0.5 to 2% by mass can be recommended, and in the case of flux brazing It is preferable to use a brazing material having an Mg concentration of 0.1% by mass or less. The balance in any of the brazing materials is Al and unavoidable impurities.

  Moreover, it is preferable to add Sr to these brazing materials in order to improve brazeability. When adding Sr, it is preferable to add so that Sr density | concentration in an Al-Si type alloy may become 0.005-0.2 mass%. If it is less than the lower limit value of the concentration of Sr, the effect of improving the brazing property can not be obtained, and large amount addition exceeding the upper limit value is uneconomical. The particularly preferred Sr concentration is 0.01 to 0.1% by mass.

[Substrate for mounting electronic device and stress relaxation layer]
The electronic element mounting substrate is sufficient if the aluminum circuit layer 22 is bonded to at least one surface of the insulating substrate 21, and the other surface may be bonded to the aluminum layer 23 as shown in FIG. And like the board | substrate 26 for electronic element mounting of FIG. 3, there may not be an aluminum layer in the other surface side, and the insulation board | substrate 21 may be directly joined to the stress relaxation layers 30 and 37. 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 device mounting substrate, as a material of which the insulating substrate 21 is made, ceramics such as aluminum nitride, aluminum oxide, silicon nitride, zirconium oxide, silicon carbide and the like can be exemplified. These ceramics can be recommended not only because they have excellent electrical insulation but also because they have good thermal conductivity and excellent heat dissipation. Further, as the aluminum circuit layer 22 and the aluminum layer 23, it is possible to recommend high purity aluminum having good conductivity and heat conductivity.

  In addition, it is preferable to use a 1000 series or 3000 series aluminum alloy having good heat conductivity, as the stress relaxation layer. The shape is preferably one having a through hole which becomes a stress absorbing space and becomes a discharge place of an oxide film at the time of brazing, but the present invention does not exclude a stress relaxation layer having no through hole.

  Further, the present invention does not limit the parts surface-bonded to the outer surface of the heat exchanger to the electronic element mounting substrate, and the method of the present invention can be applied to any parts having heat generation that can be brazed.

[Supply of brazing material on the outer surface of heat exchanger]
The brazing on the outer surface of the heat sink is surface bonding regardless of whether the counterpart material is the electronic element mounting substrate or the stress relieving layer, and the above-described Al-Si based alloy brazing material containing Fe and Bi is used. The supply method of the brazing material is not limited, and it may be integrated by being clad on a mating material, or may be supplied as brazing material foil or brazing material powder. Further, it is also possible to braze the heat sink and the mating material with a brazing sheet clad on both sides with a brazing material.

  The heat dissipation devices 1, 2 and 3 of FIGS. 1 to 3 all have a stress relieving layer as the mating material of the heat sink 10 for brazing, and the method of supplying the brazing material is different. In the heat dissipation device 1 of FIG. 1, the core material 31 is a clad material 30 in which a core material 31 is clad with an Al—Si alloy brazing filler metal 33 containing Fe and Bi as a material of a stress relieving layer. Become a stress relaxation layer. The heat dissipation device 2 of FIG. 2 is an example in which a brazing material is used as the stress relieving layer 36 and a brazing material foil 38 made of an Al-Si based alloy containing Fe and Bi is assembled. The heat dissipation device 3 of FIG. 3 also uses the stress relieving layer 37 made of a bear material, but the double-sided brazing sheet 39 is used for bonding with the heat sink 10. The double-sided brazing sheet 39 has an equal-sized through hole 39a 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 Fe and Bi. It is a brazing material.

  According to the method of manufacturing the heat dissipation device of the present invention, components with heat generation can be surface-joined well on the outer surface of the heat exchanger, and the produced heat dissipation device dissipates heat emitted from the components to the heat exchanger. It has low resistance and excellent heat dissipation performance. Moreover, since the aluminum alloy material which comprises a heat exchanger is excellent in corrosion resistance, the application meaning as a material of the heat exchanger used by more severe corrosion environment is large. One example of such a heat exchanger is the heat sink 10 which is incorporated into the heat dissipating devices 1, 2, 3 shown in FIGS. In the heat sink 10, the electronic element mounting substrate 20 is surface-bonded to the outer surface directly or through the stress relieving layer 30, and when the working fluid is water, high corrosion resistance is required not only on the outer surface but also on the inner surface. is there.

The heat sink and the stress relaxation layer were produced using the clad material, and the heat dissipation device 1 referred to in FIG. 1 was produced together with other members.
[Examples 1 to 12, Comparative Examples 1 to 5]
A two-layer clad material to be a material of the plate-like member 11 of the heat sink 10 shown in FIG. 1 was produced. The chemical compositions of the aluminum alloys constituting the core material 15 of the clad material and the brazing material 16 in Examples 1 to 12 and Comparative Examples 1 to 5 are as shown in Table 1, and the manufacturing conditions of the clad material are common.

  The aluminum alloy ingot for core material is subjected to homogenization treatment at 620 ° C for 12 hours, overlaid with the aluminum alloy ingot for brazing material, hot-rolled and clad, and the cladding thickness of the total thickness 0.8 mm, brazing material The clad material was annealed at 400 ° C. for 4 hours to form a 7% bilayer clad material.

  The area ratio of the Al—Fe-based intermetallic compound and the average particle size of the crystals of the produced cladding material 11 were examined. Moreover, the produced clad material was made into the plate shaped member 11 shown in FIG. 1 by press molding.

  The material of the stress relaxation layer 30 is such that the core material 31 is made of a 3003 aluminum alloy, the brazing material 32 on the electronic element mounting substrate 20 side is made of Al-10 mass% Si-1 mass% Mg alloy, and the heat sink 10 side brazing material 33 It is a three-layer clad material made of an aluminum alloy of a chemical composition shown in 1. The three-layer clad material has a total thickness of 1 mm, and the clad ratio of the brazing filler metals 32, 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 members in the heat dissipation device 1 are as follows.

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

Furthermore, each member was temporarily assembled into a laminate having a structure shown in FIG. 1, and the temporary assembly was vacuum brazed at 600 ° C. for 20 minutes in a vacuum of 7 × 10 ⁻⁴ Pa. The surface brazing and corrosion resistance of the brazed heat dissipation device 1 were tested and evaluated by the following method. The evaluation results are shown in Table 1.
(Face solderability)
The bonding interface of the heat sink 10 and the stress relieving layer 30 is flawed with an ultrasonic flaw detector, and the area of the stress relieving layer 30 bonded to the area (28 × 28-12 × π mm ² ) excluding the through holes 34 I checked the ratio. A bonding area ratio of 97% or more was evaluated as “o”, 95% or more and less than 97% as “Δ”, and 95% or less as “x”.
(Corrosion resistance)
OY water as the working fluid of the heat sink _{^{10 (Cl -: 195ppm, SO}} 4 2-: 60ppm, Fe 3+: 30ppm, Cu 2+: 1ppm) using, and 80 ° C. × 8 hours, and 1 cycle at normal temperature × 16 h, 20 A cyclic (480 hours) corrosion promotion test was conducted.

The corrosion depth of the inner surface of the heat sink 10 after the corrosion promotion test was measured, and the corrosion depth of less than 300 μm was evaluated as “o”, 300 μm or more and less than 600 μm as “Δ”, and 600 μm or more as “x”.
[Examples 13 to 15]
A two-layer clad material was manufactured using the same core material and brazing material as in Example 2 but changing the homogenization conditions of the core material and the annealing conditions after cladding. The homogenization conditions and the annealing conditions of 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. Moreover, the dish-shaped member 11 for the heat sink 10 was shape | molded with this two-layer clad material. The heat radiating device 1 is temporarily assembled using the same members as in Example 2 except for the plate-like member 11, and the temporary assembly is vacuum brazed at 600 ° C. for 20 minutes in a vacuum of 7 × 10 ⁻⁴ Pa. The brazeability 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, a heat exchanger using a predetermined heat sink material and a brazing material for external brazing 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 in which an electronic element mounting substrate and a heat exchanger are brazed in a wide area to the outer surface of the heat exchanger.

1, 2, 3 ... Heat dissipation device 10 ... Heat sink (heat exchanger)
11 ... dish-like member 15 ... core material (aluminum alloy material)
20, 26 ... Substrates for mounting electronic elements (parts with heat generation)
21 ... Insulating substrate 22 ... Aluminum circuit layer 30, 36, 37 ... Stress relieving layer 34 ... Through hole 33, 38, 39b ... Brazing material (Al-Si alloy brazing material containing Fe and Bi)

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 , The balance consists of Al and unavoidable impurities, and the area ratio of the Al—Fe based intermetallic compound is 0.3 to 1.5%, and the average particle size of the crystals is 50 to 500 μm,
The aluminum on the outer surface of the heat exchanger constituted of an alloy material, the component with fever, 0.02 to 0.7 mass% of Fe, beyond following 1.5 wt% 0.3 wt% Bi, 6 Manufacturing a heat dissipating device characterized by surface bonding using an Al-Si alloy brazing material containing 12 mass% of Si and 0.5 to 2 mass% of Mg and the balance being Al and unavoidable impurities Method.   The component accompanied by the heat generation is an electronic device mounting substrate to which an aluminum circuit layer for mounting the electronic device is brazed to one surface of the insulating substrate, and the surface of the electronic device mounting substrate opposite to the aluminum circuit layer. The method of manufacturing a heat dissipation device according to claim 1, wherein the heat exchanger is surface-bonded to the outer surface of the heat exchanger.   The aluminum alloy material constituting the heat exchanger further contains Cu: 0.2 to 0.7% by mass, Mg: 0.05 to 0.4% by mass, Zr: 0.05 to 0.4% by mass, V The method for manufacturing a heat dissipation device according to claim 1, wherein the heat sink contains at least one of 0.05 to 0.4% by mass and Ti: 0.05 to 0.4% by mass.   The method for manufacturing a heat dissipation device according to any one of claims 1 to 3, wherein the Al-Si based alloy brazing material contains Sr: 0.005 to 0.2 mass%.   The heat radiating 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 homogenization treatment at 600 to 640 ° C for 6 to 24 hours. Manufacturing method.   The aluminum alloy material which comprises the said heat exchanger is an alloy material to which annealing for 1 to 12 hours was performed at 350-450 degreeC, Manufacture of the heat dissipation device of any one of Claims 1-5. Method. A stress relieving layer is interposed between the electronic element mounting substrate and the heat exchanger, and the stress relieving layer is surface-joined to the outer surface of the heat exchanger using the Al-Si based alloy brazing material . 6. The manufacturing method of the heat dissipation device according to any one of 6.   The method for manufacturing a heat dissipation device according to any one of claims 1 to 7, wherein the working fluid circulating in 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, with the balance being Al and unavoidable impurities And the area ratio of the Al-Fe based intermetallic compound is 0.3 to 1.5%, and the average grain size of the crystal is 50 to 500 .mu.m.
Parts with heat generation of 0.02 to 0.7% by mass of Fe, 0.3% by mass or more and 1.5% by mass or less of Bi on the outer surface of the heat exchanger made of the aluminum alloy material What is claimed is: 1. A heat dissipating device characterized by containing 12% by mass of Si and 0.5 to 2% by mass of Mg and being surface-joined by an Al—Si alloy brazing filler metal composed of Al and unavoidable impurities with the balance being Al .   The component accompanied by the heat generation is an electronic device mounting substrate to which an aluminum circuit layer for mounting the electronic device is brazed to one surface of the insulating substrate, and the surface of the electronic device mounting substrate opposite to the aluminum circuit layer. The heat dissipation device according to claim 9, wherein the heat exchanger is surface-bonded to the outer surface of the heat exchanger.