JP5484834B2 - Heat dissipation member and method for manufacturing the same - Google Patents

Description

  The present invention has a surface comprising zinc and / or aluminum, such as metallic materials, in particular zinc and / or aluminum plating materials, galvanized aluminum, zinc and / or aluminum die casting, aluminum sheets, zinc sheets, aluminum foils and zinc foils It relates to surface treatment of materials. More specifically, the present invention relates to a heat dissipating member and a manufacturing method for heat transfer and heat radiation in black processing used for home appliances, optical equipment parts, transport equipment parts, electronic equipment parts, building materials, and the like.

  In electronic equipment parts such as optical equipment parts such as home appliances and automobile parts and lighting equipment parts, higher performance is required by speeding up and downsizing of equipment, but in general, electrical conductivity and heat of materials The conductivity is in a proportional relationship, and increasing the density of the element increases the heat generated by the device. In the device design of such electronic components, in order to increase the capacity by downsizing, while satisfying the electrical characteristics, a demand for a heat dissipation effect for increasing the life and ensuring reliability is increasing.

  As the heat dissipation material used for these purposes, aluminum and copper plates are used as materials, and aluminum plates are often used because of the relatively low cost of the materials. The heat is conducted to the heat dissipation material through the heat dissipation material, and the heat transfer from the surface of the heat dissipation material to the air is performed. Therefore, although there are various measures taken for the purpose of improving the heat dissipation characteristics, in the present invention, heat radiation is added to the heat dissipation material as one of means for further enhancing the heat dissipation effect.

  In other words, the heat dissipation material generally has a method of increasing the surface area in order to increase the heat exchange efficiency, but there is a limit in reducing the size of the heat dissipation fin interval and height in response to the demand for downsizing of the parts. On the other hand, there is a special case in which a circuit is formed by using a metallized wiring layer imparted with high thermal conductivity on an alumina ceramic insulating substrate (for example, Patent Document 1), but it is very expensive. Therefore, when considering an inexpensive processing method with high processing speed (that is, processing for several seconds), there is a black surface treatment that increases the absorption and emission of thermal energy, which is a thermal radiation function. For this, a black alumite coating method (for example, Patent Document 2) and a chemical conversion method by precipitation of fine metal particles below the wavelength of light can be used.

  To reduce the size and weight of aluminum heatsinks, in addition to adding a large amount of Si components to improve the hot water flow and demoldability of complex molding materials, a small amount is added to improve workability and durability, and improve thermal conductivity. The various metals are added. In such anodizing of alloy materials containing a large amount of metals other than aluminum, even if a dense oxidation process is performed at a low temperature, metal components such as Si, Fe and Cu that are not anodized are uniform and continuous oxidation. Not only is it impossible to cover the membrane, but the development of dedicated electrodes and jigs for electrolytic treatment, and the contrivance of contact handling tend to be an obstacle to industrialization. In addition, there is an example of heat-dissipating black treatment (for example, Patent Document 3) aiming at heat transfer to the outside air on exterior steel materials used for housings such as home appliances and office equipment, but it works for lowering the housing temperature. However, this process has not yet led to the miniaturization and longevity of electronic components.

JP 2001-189534 A JP 1996-255960 A JP 2006-291280 A

  Therefore, the present invention provides a simple measure of fine metal particles to which heat radiation is added as a heat countermeasure problem for signal delays, malfunctions, and component life reductions associated with high functionality, miniaturization and high speed of electronic device parts. The purpose of this is to suppress the temperature rise of the heat-generating component by proper precipitation and to sufficiently meet the demand for downsizing of the heat dissipation material itself.

  The present inventors diligently studied a heat radiating member provided with a layer excellent in heat energy absorption and heat release on a surface containing zinc and / or aluminum, and a method for producing the heat radiating member, and reached the present invention.

  That is, the heat dissipating member of the present invention comprises a lower layer containing nickel and / or cobalt as a main component and further containing copper and / or silver on a surface of a substrate to be treated having a surface containing zinc and / or aluminum, aluminum, It has a multilayer coating composed of an upper layer containing at least one oxide selected from magnesium, calcium, beryllium and zinc, and has an infrared emissivity of 4 to 14 μm at least 0.90. It is a sex member.

  The manufacturing method of the heat radiating member of this invention is a manufacturing method of the heat radiating member of the said structure, Comprising: The to-be-processed base material which has a to-be-processed surface containing zinc and / or aluminum is made into nickel ion and / or cobalt ion. It is a manufacturing method of a heat radiating member characterized by making it contact with the acidic aqueous solution which contains copper ion and / or silver ion as a main body.

  According to the present invention, at least one oxide selected from aluminum, magnesium, calcium, beryllium and zinc is included on a lower layer containing at least one of nickel and cobalt and at least one of copper and silver. By providing the upper layer, it is possible to provide a heat-absorbing layer excellent in coating film adhesion on the surface of the substrate to be treated containing zinc and / or aluminum by preventing the lower layer film from dropping off. This heat absorption layer is excellent in heat absorption and heat dissipation due to economical surface treatment with relatively low temperature, electroless and short-time one-step treatment on the surface of the base material containing zinc and / or aluminum. Can be obtained as a layer. Furthermore, the layer composed of the above-described structure of the heat-dissipating member of the present invention can be appropriately selected for its composition, without using harmful water-soluble antimony compounds, etc. It can also be produced on an alloy material to which various components are added in order to improve characteristics such as thermal conductivity. Therefore, the present invention has a high utility value for uses such as home appliances, optical equipment parts, transportation equipment parts, electronic equipment parts, and building materials.

It is the black alumite of the comparative example 4 in a heat dissipation rate test, and the far-infrared emissivity radiation intensity | strength chart of the wavelength of 4-14 micrometers of Example 1. FIG. It is a figure which shows the O, Zn, and Cu element spectrum measurement result in the surface analysis by ESCA of Example 1. FIG. It is a figure which shows the Ni, S, and Al element depth profile in the surface analysis by ESCA of Example 1. FIG. It is a figure which shows the depth profile in the surface analysis by ESCA of Example 1. FIG. 2 is a diagram showing an SEM image of Example 1. FIG. 2 is a diagram showing an FE-SEM image of Example 1. FIG. (A) is an FE-SEM image at 300,000 times, and (b) is an FE-SEM image at 2500,000 times the portion indicated by A in (a).

  The heat radiating member concerning this invention has the lower layer which is a heat absorption layer on the to-be-processed base material surface. The lower layer is mainly composed of nickel and / or cobalt and further contains copper and / or silver, and an upper layer containing at least one oxide selected from aluminum, magnesium, calcium, beryllium and zinc is provided on the lower layer. It is necessary to be. The heat radiation member according to the present invention has an infrared emissivity at a wavelength of 4 to 14 μm of at least 0.90, that is, less than 1, 0.90 or more, more preferably within a range of 0.90 to 0.98. Absorption and heat release properties can be obtained.

  Nickel and / or cobalt is contained as a main component of the lower layer metal component, and is preferably contained in the lower layer in a proportion of 5 to 25% by mass. The lower layer is preferably an amorphous metal layer having a film specific gravity of 5.0 or less, preferably in the range of 2.0 to 4.0. The case where nickel is mainly used for the amosphalic metal layer having a membrane specific gravity of 5.0 or less will be described. The visual appearance is black to gray-black, and the metal atoms are observed by a transmission electron microscope (TEM: 2.5 million times). This refers to those in which no crystal lattice stripes are observed. The fact that this metal layer (coating) is amorphous unlike the metal crystalline is excellent in the absorption of far-infrared heat energy and improves thermal radiation. As the specific gravity of the film having a better thermal emissivity, a rough film state of 1/2 or less of the specific gravity of metallic nickel is preferable. A range of 1/3 to 1/2 of the specific gravity of metallic nickel is more preferable. When the specific gravity of the film is less than 1/3 of the specific gravity of metallic nickel, the adhesion of the film is reduced. When the specific gravity is more than 1/2, nickel crystals grow greatly and the absorption of thermal energy may be reduced.

  The thickness of the upper layer is not particularly limited, but a thickness in the range of 0.01 to 0.5 μm, particularly 0.05 to 0.5 μm is preferable because of its excellent antireflection function. Further, the thickness of the lower layer is more preferably 0.01 to 1 μm in order to obtain a sufficient blackness. When the film thickness is within the range of both the upper layer and the lower layer, and the film specific gravity of the lower layer film is an amorphous metal layer having a film thickness of 5.0 or less, the heat dissipation is in a very good range.

  The surface to be treated of the substrate to be treated can be made of zinc, zinc alloy, aluminum or aluminum alloy. Examples of the substrate to be treated include a metal material having a surface made of zinc and / or an aluminum alloy such as zinc and / or aluminum alloy plated steel, zinc and / or aluminum alloy plated aluminum, zinc or aluminum die casting, and aluminum. In addition, glass or resin materials coated with zinc or zinc by vacuum deposition or sputtering are also included. If there is no zinc and / or aluminum on the surface of the substrate to be treated, nickel and / or cobalt preferably occupies 5 to 25% by mass, and a lower layer containing copper and / or silver, preferably the film specific gravity is 5.0 or less This is not preferable because it is difficult to form the amorphous lower layer with good adhesion. The composition of the surface of the substrate to be treated (composition of the material constituting the surface) is preferably such that at least one of zinc and aluminum is 50% by mass or more. As a preferable base material, for example, pure aluminum and JIS 1000 series are most preferable as the aluminum base, followed by 2000 series, 3000 series, 5000 series, 6000 series, 7000 series, AC material, and ADC material. These are more preferably used after being subjected to a precipitation treatment of zinc substitution including sodium zincate, potassium zincate and zinc fluoride. The magnesium alloy can also be treated by zinc substitution to form a zinc layer on the surface, thereby enabling the treatment of the present invention. Further, as the zinc-based alloy material, ZDC material, and as the zinc-coated steel material, hot dip galvanized steel, electrogalvanized steel, vacuum-deposited galvanized steel, Zn-Al alloy plated steel, etc. are preferable. Even if these materials are mixed, they can be processed simultaneously.

  In the lower layer, in addition to at least one of nickel and cobalt and at least one of copper and silver, nickel and / or cobalt, copper and / or silver metal nanoparticles, oxides, hydroxides, and components. At least one of impurities including a zinc compound and a sulfide compound generated according to film conditions can be further included.

  The upper layer that forms the heat absorption layer together with the lower layer is provided as a layer that is transparent and has a confinement effect for incident light. Therefore, the heat absorption function of the lower layer, preferably the heat absorption function of the amorphous metal layer having a film specific gravity of 5.0 or less can be further enhanced, and at the same time, the wear resistance and adhesion of the entire film as the heat absorption layer Can be improved, and the lower layer can be prevented from falling off. The upper layer can be made of, for example, any one of aluminum oxide, magnesium oxide, calcium oxide, beryllium oxide, and zinc oxide, or a mixture of two or more thereof. It is preferable that the total of these oxides is approximately 50% by mass or more (including the case of 100% by mass) of the total amount of the film components. In addition, it is particularly preferable that the upper layer contains calcium oxide or magnesium oxide, more preferably beryllium oxide, in order to improve thermal conductivity. Further, when zinc oxide is contained, the antistatic effect and the ultraviolet absorption effect can be enhanced. The two-layer structure of the film of the present invention does not need to be clearly separated from the upper layer and the lower layer, and may be a composition gradient structure in which the composition gradually changes. The upper layer may also contain an impurity containing a zinc compound or a sulfide compound generated according to the film forming conditions.

  A transparent protective layer made of an inorganic material or an organic material having a thickness of 0.05 to 5 μm can be formed as the uppermost layer further on the upper layer. That is, anticorrosion may be required depending on the environment used, and the type and film thickness of the uppermost layer can be selected according to the expected service life. For example, the inorganic material includes a Zr compound, a Ti compound, or an Si compound, and the organic material includes a fluorine varnish and a silicone varnish.

As a manufacturing method of the heat radiating member of this invention, the following two methods can be mentioned.
(1) A substrate to be treated having a surface to be treated containing zinc and / or aluminum, at least one of nickel ions and cobalt ions, at least one of copper ions and silver ions, and optionally fluorides After contacting with an aqueous solution containing ions, at least one of nickel and cobalt and a lower layer containing at least one of copper and silver, preferably an amorphous metal layer, aluminum, magnesium A first method of forming an upper layer containing at least one oxide selected from calcium, beryllium and zinc.
(2) A substrate to be treated having a surface to be treated containing zinc and / or aluminum, and at least one of nickel ions and cobalt ions, at least one of copper ions and silver ions, zinc ions, and Accordingly, by contacting with an aqueous solution containing fluoride ions, at least one of nickel and cobalt and a lower layer containing copper and silver, preferably a lower layer of an amorphous metal layer having a film specific gravity of 5.0 or less A second method of starting formation and forming an upper layer containing at least one oxide selected from aluminum, magnesium, calcium, beryllium and zinc simultaneously with the lower layer.

  In the present invention, the treatment liquid for forming the lower layer of the amorphous metal having a film specific gravity of 5.0 or less requires at least one of nickel ions and cobalt ions and at least one of copper ions and silver ions. Depending on the case, an aqueous solution containing fluoride ions can be used. The concentration of fluoride ions is preferably 1.0 mol / L or more, and the upper limit is the saturation amount (saturation amount determined from the amount of cations in the treatment liquid, pH, solubility when added as a fluoride salt, etc.). By further containing at least one oxide selected from aluminum, magnesium, calcium, beryllium and zinc in the treatment liquid, the formed lower layer is grown, and substantially transparent aluminum is then formed thereon. At least one oxide selected from magnesium, calcium, beryllium and zinc is precipitated, and the lower layer and the upper layer can be formed simultaneously by one treatment.

  Add nickel ion, cobalt ion, copper ion and silver ion in the treatment solution in the form of sulfate, nitrate, chloride, fluoride, carbonate, acetate, oxalate, hydroxide, oxide, etc. Can do. In particular, sulfide, chloride, carbonate (basic carbonate) and hydroxide are preferable.

  When the surface to be treated of the substrate to be treated is aluminum or an alloy thereof, it is more preferable that fluoride ions are contained as an etching aid. In the presence of fluoride ions, a good appearance can be obtained even if the aluminum material is directly treated without being subjected to zinc substitution treatment. Fluoride ions can be replenished simultaneously by adding them as sulfates, nitrates, chlorides, acetates, oxalates, etc. when supplying nickel, cobalt, copper or silver.

  Although the pH of a process liquid is not specifically limited, It is preferable that it is 7 or less, and the range of 2-6 is more preferable.

  In the treatment liquid of the present invention, when both metal ions of nickel and cobalt are used, it is preferable that nickel ions are 2 to 9 parts by mass and the balance is cobalt ions out of a total of 10 parts by mass of metal ions. If the nickel ion is less than 2 parts by mass, a film with an amorphous metal layer having a sufficient film specific gravity of 5.0 or less may not be obtained depending on the material type. . The concentration of at least one of nickel and cobalt in the treatment liquid is preferably 1 to 50 g / L, and more preferably 2 to 30 g / L. The ion concentration of copper and / or silver is preferably 0.1 mol% or more with respect to the ion concentration of nickel and / or cobalt, more preferably in the range of 0.02 to 0.2 mol%, and 0.01 mol%. If it is less than%, an amorphous metal film having a film specific gravity of 5.0 or less may not be sufficiently obtained, and even if it exceeds 2 mol%, a good film may not be obtained. With such a treatment liquid, the ratio of copper and / or silver to nickel and / or cobalt in the lower layer of the resulting film is preferably in the range of 25 to 40% by mass.

  These compounds for preparing a treatment liquid are dissolved in water to prepare a treatment liquid, but the treatment liquid may contain a solvent other than water as long as the effect is not impaired. In that case, a solvent compatible with water, such as alcohols, can be selected. The concentration of the treatment liquid is not particularly limited as long as it is a concentration range in which the additive compound can be dissolved, but it is preferably 3 to 200 g / L as metal ions. If it is less than 3 g / L, a long time is required for the treatment, and if it exceeds 200 g / L, a partially undissolved salt may be precipitated. Aluminum, magnesium, or zinc is preferably added to the treatment liquid, and the total concentration is more preferably 0.05 to 20 g / L.

  When the surface to be treated containing zinc and / or aluminum is brought into contact with the treatment liquid, zinc and / or aluminum is eluted from the surface to be treated, and Ni and Co ions in the liquid are formed into nano-particles on the material surface by the substitution reaction. Alternatively, an amorphous metal film having a film specific gravity of 4.0 or less can be obtained. Further, when copper ions and / or silver ions are contained in the treatment liquid, Ni and / or silver ions are delayed while copper and / or silver ions precede the Ni and / or Co ions. Alternatively, a Co ion substitution reaction starts, and as a result, an amorphous metal film having a film specific gravity of preferably 4.0 or less can be stably formed. In both cases, if ions, oxides, etc. of aluminum, magnesium, zinc, etc. are present in the liquid, the oxides of aluminum, magnesium, calcium, beryllium, zinc are deposited as the pH increases at the interface. A film having excellent adhesion is obtained because it is deposited on the film and prevents re-dissolution of the film layer. After the treatment, the upper layer containing at least one oxide selected from aluminum, magnesium, calcium, beryllium, and zinc deposited by washing with water and drying is preferably a lower layer, preferably a film specific gravity. It becomes a protective film of an amorphous metal lower layer of 4.0 or less, and the adhesion and durability of the film are improved and it becomes an antireflection layer, and the infrared absorption performance is also improved. When at least one ion of aluminum, magnesium, calcium, beryllium, and zinc is not present in the treatment liquid, a transparent oxide layer is difficult to be formed. Therefore, an oxide sol of aluminum, magnesium, calcium, beryllium, zinc, Preferably, a precursor solution in which these metals are dissolved is applied and baked to form an upper layer containing at least one oxide of aluminum, magnesium, calcium, beryllium, and zinc. As a component of the precursor solution, oxalate, maleate, nitrate, chloride, β-diketone complex of aluminum, magnesium, calcium, beryllium, zinc is preferable. It is also preferable to form an upper layer by a method in which zinc hydroxide is precipitated by contact with an acidic solution containing aluminum, magnesium, calcium, beryllium, and zinc, followed by drying after washing with water.

  When carrying out the present invention, the method of contacting the treated surface of the substrate to be treated with the treatment liquid includes immersing the treated substrate in the treatment liquid or spraying the treated surface of the treated substrate by spraying or the like. A method of bringing the treatment liquid into contact with the coating can be employed.

  Although it does not restrict | limit especially as processing temperature, It is desirable to process in the range of 0-80 degreeC, Preferably it is the range of 20-50 degreeC. Although the treatment time cannot be generally limited by the concentration of the treatment liquid, the treatment method, the treatment temperature, etc., the treatment liquid and the metal material material are usually contacted for several seconds to several minutes, preferably 5 to 180 seconds. If the treatment time is too long, the deposited nanoparticulate metal or oxide has a large particle size and may deteriorate the heat absorption performance or impair the shape of the material surface. Further, it is desirable to remove the treatment liquid immediately after washing by washing with water or the like. It is also desirable to perform a pretreatment such as degreasing according to a conventional method before contacting with the treatment liquid.

  Even if the boundary between the lower layer and the upper layer in the present invention is formed as a clear boundary (interface) in which these compositions change, the lower layer composition is formed as a boundary that becomes an upper layer by changing continuously or intermittently. Also good.

  Moreover, after performing a roughening process on the surface of a to-be-processed base material previously, the multilayer film mentioned above can also be formed. The degree of roughening can be appropriately set so that the heat exchange rate between the substrate to be treated and the multilayer coating can be increased to further improve the heat dissipation. For example, the surface is preferably roughened so that Ra (JIS-B-0633-2001: arithmetic average surface roughness) is in the range of 0.5 to 10 μm. As a method of surfaceization for increasing the surface roughness of the substrate to be treated, for example, a blast treatment is given as a physical method, and a chemical etching combination can be used as a chemical method in addition to pickling. It is.

  The present invention will be described below with reference to examples and comparative examples. The present invention is not limited to the scope shown in the following examples.

(Examples 1-4 and Comparative Examples 1-5)
Examples 1 to 4 and Comparative Examples 1 to 5 will be described below. A treatment liquid having the composition shown in Table 1 was prepared, and test materials were produced under the conditions shown in Table 2.
Test plate:
As a test plate, an ADC12 aluminum plate (thickness 1 mm, 50 × 100 mm) was degreased, washed and dried with an alcal degreasing agent (FC-315 manufactured by Nippon Parkerizing Co., Ltd.), and a sodium hydroxide solution. Two types of zinc-coated aluminum plates were used which were treated with a zinc-displacement plating bath prepared by dissolving zinc oxide for 30 seconds and whose surfaces were coated with metallic zinc.

  A treatment solution having the composition shown in Table 1 was prepared (using pure water as a solvent), the treatment solution containing fluoride ions was heated to 45 ° C., and the test plate was immersed for 30 seconds, and the lower layer and the upper layer were simultaneously formed on the surface. Formed. After the treatment, it was washed with water and dried at 150 ° C. for 5 minutes. In Examples 1-4 and Comparative Examples 1-5, zinc-coated aluminum plates were used as test plates. The pH of the liquid was adjusted with dilute sulfuric acid or aqueous ammonia.

(Example 5)
The solution was applied to a 2 g / m ² of the fluorine resin varnish treated plate produced by the process liquid composition 1 and the same zinc-coated aluminum plate as in Example 1 (Kanto Denka Kogyo Co., Ltd. KD270), dried at 80 ° C. To prepare a test plate.
(Example 6)
A coating of alumina sol 10 g / L was applied to a treatment plate produced with the same treatment solution composition 1 of Example 1 on an aluminum plate of ADC12 not coated with zinc so as to have a film thickness of 0.5 μm and dried at 150 ° C. To prepare a test plate.
(Example 7)
A treated plate made of the same zinc-coated aluminum plate as in Example 1 and treated solution composition 1 was immersed in 10 g / L of silica sol (Snowtex N manufactured by Nissan Chemical Co., Ltd.) for 20 seconds and dried at 150 ° C. for 1 hour. A test plate was prepared by forming an upper layer of silicon oxide on the surface.

(Comparative Example 6)
In order to compare the emissivities, a black alumite film 10 μm was prepared on the material ADC12 (70 × 50 × t 2 mm).
(Comparative Example 7)
In order to compare the emissivities, a heat-dissipating paint “Cooltech CT-100” coated product 20 μm manufactured by Okitsumo Co., Ltd. was prepared on the material ADC12 (70 × 50 × t 2 mm).

The following performance evaluation was performed about the obtained test material.
1) Appearance: Evaluation was performed by measuring the L value of the test material surface as an index of light absorption performance with a color difference meter (color meter manufactured by Nippon Denshoku Industries Co., Ltd.). .
2) Abrasion resistance: The surface of the test material was rubbed 20 times with white paper (Kimwipe), and the amount of the black film that had fallen off and adhered to the paper was visually determined.
A: No adhering B: Somewhat adhering C: Black paper 3) Emissivity test (measurement of far-infrared emissivity with a wavelength of 4 to 14 μm): 10 cm spacing at the center of one side of the test panel Hot air is blown vertically from the opposite side, and the radiation intensity is measured with a spectral emissivity meter from the opposite side. The temperature range is 60-62 ° C. Spectral emissivity meter: “Infrared emissivity meter” manufactured by Nihon Burns Co., Ltd. is used. As the emissivity ε approaches 1.0, the thermal emissivity is excellent. The evaluation results are shown in Table 3. Moreover, in FIG. 1, the black alumite of the comparative example 4 in the heat dissipation rate test and the far-infrared radiation rate radiation intensity chart of the wavelength 4-14 micrometers of Example 1 are shown.
4) Film specific gravity mainly composed of Ni: One sample (10 cm × 10 cm) was used for measuring the film thickness, and the other half was used for measuring the film weight. The film thickness measurement sample is divided into three parts at the center and both ends, and the average film thickness mainly composed of Ni is calculated from the SEM images of the film cross-section from these three sheets (in some cases, mapping of EDS analysis results is also used) . Thereafter, the film is dissolved and removed from the remaining half with a nitric acid solution, the weights before and after the film are measured, and the amount of each component metal of the film is measured by ICP analysis of the film solution. The membrane specific gravity is calculated from these numerical values. Scanning electron microscope: JSM-6490 is used.
5) Chemical state analysis and surface analysis: X-ray photoelectron spectroscopic analyzer (ESCA-3400) is used as a constituent element analysis of the coating surface layer.

  Moreover, in order to confirm these film | membrane structures, the surface analysis by ESCA was implemented. As a result, it was confirmed that in each Example and each Comparative Example, all the generated films were composed of an upper layer having a thickness of 0.01 to 0.5 μm and a lower layer having a thickness of 0.1 to 1 μm. As a representative example of the film analysis result of Example 1, FIG. 2 shows each element spectrum measurement result in the surface analysis by ESCA, and FIG. 3 and FIG. When the intersection of the coating component Zn and the raw material component Al is defined as the interface, the coating thickness is about 220 nm, and the coating is generally a mixture of Zn, Ni, and Cu, not a tilted film of Zn and Ni. Characteristically, Cu tends to be unevenly distributed on the surface layer side and Ni is on the substrate side. This is performed simultaneously with Cu and Ni in substitutional precipitation with Zn, and Cu is more noble than Ni. It can be judged that it was a large amount of metal and deposited on the surface layer side to become the base point of the reaction. In addition, a very slight Zn peak was confirmed on the surface layer.

Furthermore, in order to confirm that this lower layer is in an amorphous state with a rough film specific gravity, FIG. 5 shows an SEM image, and FIGS. 6A and 6B show an FE-TEM image. From the SEM film observation of FIG. 5, the Ni-based lower layer has irregularities with a spacing of about 100 to 300 nm, while in the FE-TEM observation shown in FIGS. The diffraction fringes of the electron beam were not observed at about 300 nm. That is, almost no electron beam scattering was observed. In addition, the Ni adhesion amount at this time was 189 mg / m ^2, and the film specific gravity of the Ni layer was calculated with an average film thickness of 150 nm, which was 2.83. Since the specific gravity of the metal Ni is 8.902, it can be determined that the metal Ni has a rough amorphous shape with a specific gravity of about 1/3.

Claims (16)

  On the surface of the substrate to be treated having a surface containing zinc and / or aluminum, the lower layer mainly containing nickel and / or cobalt and further containing copper and / or silver and aluminum, magnesium, calcium, beryllium and zinc are selected. A heat-dissipating member having a multilayer film comprising an upper layer containing at least one oxide and having an infrared emissivity of 4 to 14 μm at least 0.90.   2. The heat dissipating member according to claim 1, wherein the infrared radiation emissivity at a wavelength of 4 to 14 μm is less than 1 and 0.90 or more.   The heat dissipating member according to claim 1 or 2, wherein the film specific gravity of the lower layer is 5.0 or less.   The heat-dissipating member according to claim 3, wherein the lower layer has a specific gravity of 2.0 to 4.0.   The heat dissipation member according to any one of claims 1 to 4, wherein the lower layer contains 5 to 25 mass% of nickel and / or cobalt.   The heat radiating member according to claim 1, wherein the lower layer has a thickness of 0.1 to 1 μm.   The heat dissipation member according to any one of claims 1 to 6, wherein the upper layer has a thickness of 0.01 to 0.5 µm.   The heat dissipating member according to any one of claims 1 to 7, further comprising a transparent protective layer as an uppermost layer on the upper layer.   The heat radiating member according to any one of claims 1 to 8, wherein the surface of the substrate to be treated is subjected to a roughening treatment in advance. On the surface of the substrate to be treated having a surface containing zinc and / or aluminum, the lower layer mainly containing nickel and / or cobalt and further containing copper and / or silver and aluminum, magnesium, calcium, beryllium and zinc are selected. A method for producing a heat-dissipating member having a multilayer film comprising an upper layer containing at least one oxide and having an infrared emissivity of at least 0.90 at a wavelength of 4 to 14 μm,
Heat dissipation characterized by bringing a substrate to be treated having a surface to be treated containing zinc and / or aluminum into contact with an acidic aqueous solution mainly containing nickel ions and / or cobalt ions and further containing copper ions and / or silver ions. A method for manufacturing a structural member.   The method for producing a heat-dissipating member according to claim 10, wherein the infrared radiation emissivity at a wavelength of 4 to 14 μm is less than 1 and 0.90 or more. The method for manufacturing a heat dissipation member according to claim 10 or 11, wherein an ion concentration of the copper and / or silver is at least 0.1 mol% with respect to an ion concentration of nickel and / or cobalt. The method for producing a heat radiating member according to claim 12, wherein an ion concentration of the copper and / or silver is 2 mol% or less with respect to an ion concentration of nickel and / or cobalt.   The method for producing a heat radiating member according to claim 10, wherein the acidic aqueous solution further contains fluorine ions.   The manufacturing method of the heat radiating member in any one of Claims 10-14 which performs a roughening process on the said to-be-processed base material surface previously.   The manufacturing method of the heat radiating member in any one of Claim 10 to 15 which has the process of providing a transparent protective layer as an uppermost layer further on the said upper layer.