JP4903476B2 - Colored surface-treated metal sheet for soldering - Google Patents

Description

The present invention relates to a colored surface-treated metal sheet for soldering having high solder wettability and workability.

Conventionally, a plated metal plate in which at least one surface is plated with a solderable metal is generally known. An example of the plated metal is a plated steel plate. A colored surface-treated steel sheet in which an organic resin film containing a pigment is formed on the surface of the plated steel sheet to color the surface of the plated steel sheet to improve radiation efficiency is known.
JP 2005-139489

  As described in “0042”, the formation of a resin film on the surface of a plated steel sheet in Patent Document 1 is performed by applying a resin liquid containing yellow, black, or red-based color pigment or titanium carbide to the plated steel sheet. The coating is performed by dipping / squeezing and then dried at a temperature of 90 ° C. The resin film is composed of a single layer film formed on the plating surface.

  The resin film contains hard titanium carbide or a pigment that is a solder wetting inhibitor that inhibits solder wetting of the metal plate. When the colored surface-treated steel sheet is soldered, titanium carbide and pigment are not easily melted and may remain on the surface of the soldered portion of the colored surface-treated steel sheet. In this case, there was a drawback that the solder wettability was lowered.

  On the other hand, the resin film on the surface of the colored surface-treated steel sheet is hard due to titanium carbide. For this reason, there existed a fault that workability was low, for example in the point that a burr | flash generate | occur | produces easily at the time of press work, the point with a large abrasion degree of a metal mold | die, etc.

In order to solve the above problems, the colored surface-treated metal plate for soldering of the present invention has an organic resin film layer 3 on the surface of a plated metal plate in which at least one surface of the metal plate 1 is plated with a metal plating layer 2. In the surface-treated metal plate on which is formed, the plating layer 2 is composed of a zinc plating layer, a plating layer obtained by sequentially plating zinc and nickel, or a plating layer obtained by sequentially plating zinc, nickel and tin. The organic resin film layer 3 is composed of two layers, and the first film layer 3a in contact with the metal plate 1 in the organic resin film layer 3 is a transparent film containing no pigment, and the second film layer 3b which is the outermost layer. Is a colored film containing the pigment as a first feature.

  Second, the second coating layer 3b is colored dark.

  Third, the plated metal plate is made of a plated steel plate or a plated aluminum plate.

Fourth, the pigment of the second coating layer 3b is a magnetic material.

Fifth, the pigment is made of a substance containing nanocarbon.

  According to the structure of the present invention configured as described above, the second coating layer containing the pigment which is a solder wetting inhibitor that inhibits the solder wettability of the metal plate is a transparent first coating layer that does not contain the pigment. An organic resin film layer is formed on the surface.

  When soldering this colored surface-treated metal plate, the first coating layer is formed directly on the surface of the metal plate, but it does not contain a pigment that is a solder wetting inhibitor, so it is easily affected by heat during soldering. Melt. Since the second coating layer is formed on the surface of the first coating layer, it is easily melted by heat during soldering as the first coating layer is melted.

  As a result, the soldered portion of the colored surface-treated metal plate adheres to the surface of the plated metal plate while the organic resin film layer is easily melted and almost no pigment remains. For this reason, solder wettability is improved. Except for the soldered portion, the organic resin film prevents oxidation and discoloration of the metal plate itself, whisker after soldering, and generation of rust.

  On the other hand, the first coating layer in the organic resin coating layer does not contain a pigment that is a solder wetting inhibitor and is relatively soft. For this reason, when the second coating layer is a hard coating layer containing, for example, hard titanium carbide, the first coating layer can function as a cushion to suppress the generation of burrs during press processing. It is also possible to suppress the wear of the mold used in the process. By making the second coating layer hard as described above, peeling or damage of the coating can be prevented.

  By coloring the second coating layer to a dark color, for example, black, the radiation property of the colored surface-treated metal plate is improved. In particular, compared with the case where a dark film is directly formed on the surface of the plated metal plate, the dark film (second film layer) of the colored surface-treated metal plate has a higher affinity for the second film layer. Since it is formed with respect to one film layer, it rides well and black spots are prevented. By preventing color spots, radiation characteristics are stably improved.

  For example, when a plated steel plate is used as the plated metal plate, the radiation performance can be equal to or higher than that of an aluminum plate that is not surface-colored. When a plated aluminum plate is used as the plated metal plate, higher radiation performance can be provided.

  For this reason, by forming the heat sink from the colored surface-treated metal plate, it is possible to provide a heat sink having high solder wettability and high radiation when soldering to a substrate or the like. High workability when pressing heat sinks.

  By making the pigment of the second film a magnetic material, the entire surface of the colored surface-treated metal plate can be covered with a magnetic material, and the colored surface-treated metal plate itself can be made a magnetic material. Thereby, this coloring surface treatment metal plate can be used for a magnetic shield, and a lightweight shield case etc. can be comprised by using a plating aluminum plate as a plating metal plate.

  By using the substance containing nanocarbon as a pigment, the current density, hardness, conductivity improvement, and other performances that nanocarbon can have can be given to the surface of the colored surface-treated metal plate.

  FIG. 1 is a cross-sectional image view showing the structure of a colored surface-treated aluminum plate that is a colored surface-treated metal plate of the present invention. FIG. 2 is an image diagram showing an outline of the manufacturing process of the colored surface-treated aluminum plate. This colored surface-treated aluminum plate is obtained by forming the organic coating layer 3 on the surface of the plated aluminum plate (the surface of the plated layer 2) in which the plated layer 2 is formed on both the front and back surfaces of the aluminum plate 1.

  The plating layer 2 is formed by sequentially plating zinc and nickel on the aluminum plate 1. The plated layer 2 is a layer in which a zinc layer Zn is formed in contact with the aluminum plate 1, and a nickel layer Ni is formed in contact with the zinc layer Zn.

  The zinc layer Zn is formed, for example, by performing zinc substitution plating on the aluminum plate 1. Nickel is plated on the zinc layer Zn formed by displacement plating by alkali plating or the like to form a nickel layer Ni. The surface of the plating layer 2 is nickel that can be soldered.

  As shown in FIG. 2, in order to form the organic coating layer 3 after the plating, a water-based acrylic resin containing a water-based urethane resin, a water-soluble rosin, or the like is applied to both the front and back surfaces of the plated aluminum plate.

  The aqueous acrylic resin can be applied by immersing the plated aluminum plate in the aqueous acrylic resin liquid. The water-based acrylic resin (liquid) is transparent and does not contain solder wetting inhibitors that remain when soldering, such as pigments and titanium carbide, and inhibit solder wettability.

  After applying the water-based acrylic resin, it is once dried. This drying can be performed, for example, at a temperature of about 90 ° C. for about 3 minutes. Thereby, the transparent first film layer 3a made of the water-based acrylic resin is formed. The first coating layer 3a does not contain the above solder wetting inhibitor (such as pigment or titanium carbide). Also, hard materials such as titanium carbide are not included.

  After the formation and drying of the first coating layer 3a, the surface of the first coating layer 3a is coated with a black aqueous acrylic resin mixed with a black pigment in addition to the aqueous urethane resin and water-soluble rosin. The application of the black water-based acrylic resin can be performed by immersing a plated aluminum plate having the first film layer 3a formed on the surface in a black water-based acrylic resin solution. Thereafter, the same drying treatment as described above is performed.

  As a result, a black second coating layer 3b is further formed on the surface of the first coating layer 3a. The organic coating layer 3 is composed of two coating layers, a first coating layer 3a and a second coating layer 3b. The surface of the colored surface-treated aluminum plate is colored and blackened by the second coating layer 3b.

  In this specification, the term “pigment” refers to a broadly defined pigment including a colored substance capable of coloring a water-based acrylic resin in addition to a narrowly defined pigment generally used for paints and the like. In this embodiment, titanium carbide is used as a black pigment in addition to a pigment having a narrow black color. The black color includes not only perfect black color strictly defined as R / G / B = 0% / 0% / 0% but also all colors that are generally recognized as black.

  When soldering this colored surface-treated aluminum plate, the first coating layer 3a is formed directly on the surface of the plating layer 2, but does not contain solder wetting inhibitors such as hard titanium carbide or narrowly defined pigments. Therefore, it is easily melted by heat during soldering and hardly remains.

  The surface second coating layer 3b contains a solder wetting inhibitor such as hard titanium carbide or narrowly defined pigment, but is formed in contact with the surface of the first coating layer 3a. 3a is easily melted by heat at the time of soldering and hardly remains.

  The molten portion of the organic coating layer 3 can be soldered because the nickel layer Ni is bare. As described above, in the colored surface-treated aluminum plate, the first coating layer 3a and the second coating layer 3b are easily melted during soldering, and the surface nickel where the coating layers 3a and 3b hardly remain is soldered. Solder wettability is high and soldering is performed firmly.

  Since the second coating layer 3b is formed by repeatedly applying the black resin to the once dried transparent resin (first coating layer 3a), the black of the water-based acrylic resin becomes patchy when forming the second coating layer. And black spots on the black surface hardly occur. Thereby, this coloring surface treatment aluminum plate improves radiation efficiency by the black surface. The colored surface-treated aluminum plate can be colored with a dark color other than black according to the color and type of the pigment to be mixed. However, the radiation efficiency is lower than that of black.

  In the present colored surface-treated aluminum plate, the base of the organic coating layer 3 is nickel, and the nickel surface is covered with a water-based acrylic resin coating. Therefore, the nickel layer Ni and the organic coating layer 3 are used to oxidize the aluminum plate 1 itself. Discoloration, whisker and rust are prevented. Since titanium carbide is included, the hardness of the surface of the organic coating layer 3 (the surface of the second coating layer 3b) is improved, and the generation of scratches on the surface can be prevented.

  As described above, the surface of the colored surface-treated aluminum plate is hard due to titanium carbide or the like. For example, when performing press working or the like, the soft first coating layer 3a that does not include a hard substance such as titanium carbide is formed. It functions as a cushion, suppresses the occurrence of burrs and cracks, and can suppress wear of the press mold.

  For example, when the heat sink H as shown in FIG. 3 is formed, press workability is high, and the radiation efficiency and solder wettability of the heat sink H can be improved. Further, since the heat sink H has a high surface hardness, it can prevent surface scratches (black baldness, etc.).

  A magnetic powder that is a black body can also be used as the pigment. In this case, magnetic powder is contained in the second coating layer 3b on the surface of the colored surface-treated aluminum plate. As the magnetic powder, finely pulverized permalloy, ferrite, iron powder and the like can be considered. In this case, the colored surface-treated aluminum plate can be handled as a magnetic material.

  Any magnetic material other than magnetic powder can be used. When using magnetic powder such as iron powder that may cause rust, a rust preventive material may be mixed into the water-based acrylic resin in order to prevent rust.

  In the case of the colored surface-treated aluminum plate that can be handled as a magnetic material as described above, since it can be magnetically shielded, it can be used for a lightweight magnetic shield case made of aluminum, for example.

  In this case, since the magnetic shield case can be soldered as described above, the leg can be easily attached to the board by providing a leg for attachment to the board and soldering the leg to the board. In addition, the magnetic shield case can be easily manufactured by folding the colored surface-treated aluminum plate formed in the development type of the magnetic shield case into a case shape and soldering the bent portion.

  Nanocarbon can also be included in the pigment. Nanocarbons such as carbon nanotubes and nanohorns themselves have a high current density and hardness, as well as high conductivity, as is conventionally known. In addition, new structural materials that exhibit new electrical and mechanical properties can be produced using nanocarbon.

  By using a substance containing nanocarbon as a pigment, it is possible to give the surface of the colored surface-treated metal plate the current density, hardness, conductivity improvement, and other performances that the above-mentioned nanocarbon can have. . By using black nanocarbon, nanocarbon itself can be used as a black pigment.

  Although the nickel layer Ni is the surface of the plating layer 2 as described above, tin may be formed on the nickel layer Ni by plating tin to form a tin layer. When tin is used as the surface, tin bares when the organic coating layer 3 is melted, so that the solder wettability is further improved and soldering becomes easier.

  When the surface of the plating layer 2 is tin, a trisodium phosphate solution (Na3PO4), which is a solution of trisodium phosphate, is once attached to the entire surface of the plating layer 2 before forming the first coating layer 3a. The first coating layer 3a can also be formed on the surface of the plating layer 2 after drying.

  For example, the entire aluminum plate 1 on which the plating layer 2 is formed is immersed in a bath filled with a sodium phosphate solution, and then pulled up from the sodium phosphate solution, whereby the surface of the plating layer 2 is entirely covered with phosphorus. An acid soda solution can be deposited.

  After the plating layer 2 is formed, the entire surface is once immersed in a sodium phosphate solution to remove impurities and dirt on the surface (tin layer) of the plating layer 2, and the tin layer is almost free of impurities and dirt. Then, since this surface is covered with the first film layer 3a of the water-based acrylic resin, the oxidation and discoloration of the aluminum plate itself, whisker and rust are suppressed.

  As the surface treatment of the plated aluminum plate before the first coating layer 3a is formed, a surface treatment (primary treatment) with a silane coupling agent can be performed in addition to the above-described third sodium phosphate solution adhesion treatment. By performing the base treatment with the silane coupling agent, the adhesion strength and peeling strength of the first coating layer 3a are improved, and the organic coating layer 3 is not easily peeled off. A surface treatment with a silane coupling agent may be performed after the surface treatment with the third sodium phosphate solution.

  FIG. 4 is a cross-sectional image diagram showing the structure of a colored surface-treated steel sheet that is a surface-treated metal sheet of the present invention. In the colored surface-treated steel sheet, a steel sheet 6 is used in place of the aluminum plate 1 described above. Since the structure and the formation process of the plating layer 2 and the organic coating layer 3 are the same as those of the colored surface-treated aluminum plate described above except that the steel plate 6 is used instead of the aluminum plate 1, detailed description thereof is omitted.

  As in the case of the above-mentioned colored surface-treated aluminum plate, when soldering this colored surface-treated steel plate, the organic coating layer 3 in the soldered portion is easily melted by the heat at the time of soldering. Highly soldered firmly.

  As in the case of the colored surface-treated aluminum plate described above, the black color of the water-based acrylic resin is prevented from becoming patchy during the formation of the second coating layer, and the black colored surface treatment hardly occurs. The steel sheet has improved radiation efficiency due to the black surface. The surface hardness can be improved by using titanium carbide as a black pigment. A magnetic substance can be obtained by using magnetic powder or other magnetic substance as a pigment. Workability can also be improved while making the surface hard.

  In addition, as shown in FIG. 5, the organic coating layer 3 consisting of the first coating layer 3a and the second coating layer 3b can be formed on the surface of the galvanized steel sheet in which the plating layer 2 consists of the zinc layer Zn as described above. . In this case, the same effect as described above can be obtained.

  In the said embodiment, although the example which used the plated aluminum plate and the plated steel plate was demonstrated as a plated metal plate, what consists of metals other than aluminum and steel can also be used as a metal plate. Also in this case, the same effect as described above can be obtained by forming the plating layer 2 and the organic coating layer 3 on the surface of the plated metal plate in the same manner as described above.

  For any of the above-mentioned surface-treated metal plates, a metal film can be plated on the surface of the first film layer 3a by displacement plating or the like to form the second film layer 3b on the metal film. In this case, since the metal film between the first coating layer 3a and the second coating layer 3b is extremely thin, it hardly hinders melting of the second coating layer 3b during soldering.

  For any of the above-described surface-treated metal plates, one or more film layers made of an aqueous acrylic resin or the like can be provided between the first film layer 3a and the second film layer 3b. However, as the number of layers increases, the solder wettability decreases. Therefore, when the organic coating layer 3 is made into a plurality of layers of two or more layers, it is necessary to keep it within the allowable solder wettability range.

It is a cross-sectional image figure which shows the structure of this coloring surface treatment aluminum plate. It is an image figure which shows the outline | summary of the manufacturing process of this coloring surface treatment aluminum plate. It is a perspective view of the heat sink manufactured by this coloring surface treatment aluminum plate. It is a cross-sectional image figure which shows the structure of a coloring surface treatment steel plate. It is a cross-sectional image figure which shows the structure of another coloring surface treatment steel plate.

1 Aluminum plate (metal plate)
2 plating layer 3 organic resin coating layer 3a first coating layer 3b second coating layer

Claims (5)

In the surface-treated metal plate in which the organic resin film layer (3) is formed on the surface of the plated metal plate in which at least one surface of the metal plate (1) is plated with the metal plating layer (2) , the plated layer (2 ) Consists of a zinc plating layer, a plating layer formed by sequentially plating zinc and nickel, or a plated layer formed by sequentially plating zinc, nickel and tin, and the organic resin film layer (3) is formed of two layers. The first film layer (3a) in contact with the metal plate (1) in the organic resin film layer (3) is a transparent film containing no pigment, and the second film layer (3b) serving as the outermost layer is the above-mentioned A colored surface-treated metal plate for soldering, which is a colored film containing a pigment. The colored surface-treated metal sheet for soldering according to claim 1, wherein the second coating layer (3b) is colored dark. The colored surface-treated metal plate for soldering according to claim 1 or 2, wherein the plated metal plate comprises a plated steel plate or a plated aluminum plate . The colored surface-treated metal plate for soldering according to any one of claims 1 to 3, wherein the pigment of the second coating layer (3b) is a magnetic substance. The colored surface-treated metal sheet for soldering according to any one of claims 1 to 4, wherein the pigment is made of a substance containing nanocarbon.

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