JP2005154864A - High rigidity and high hardness plating method for casing made of resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the rigidity and hardness of resin plating by using nickel sulfamate for a plating bath, thus performing plating treatment having high uniformity. <P>SOLUTION: A catalyst is adsorbed on a casing made of resin such as light electrical products, e.g., a portable telephone and a notebook personal computer. A base metal is precipitated over the casing made of resin by an electroless plating bath. The casing made of resin is dipped into a plating bath obtained by adding organic acid or organic acid salt such as acetic acid or nickel acetate into a nickel sulfamate bath or a nickel sulfamate-cobalt bath, and nickel is electrolytically precipitated so that the thickness of the nickel plated film reaches about 5 to 30 μm. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin plating technique for performing metal plating on a resin casing, and more particularly to a high-rigidity and high-hardness plating method capable of uniformly plating a plating film thickness of a resin casing.

  High rigidity is required for the housing of weak electrical products such as mobile phones and notebook computers. Therefore, a metal casing formed by Mg die-casting or thixo molding has been conventionally used. For example, in order to substitute for a metal casing such as Mg, rigidity has been increased by thickening metal by electroplating on a resin casing such as polycarbonate resin, polycarbonate / ABS resin, or the like.

  A resin plating method for the resin casing is performed by thickening general decorative plating such as bright copper plating (high copper sulfate bath) or bright nickel plating (watt bath). The film thickness at this time was about 15 to 30 μm. However, when a resin casing is resin-plated with these general plating solutions for decorative plating, plating deposits are extremely concentrated on the convex portions of the resin casing, resulting in a bulging portion, resulting in uneven plating film thickness. It was easy to be. For this reason, the dimensional cleanliness of the plated resin casing is poor, and there is a problem in fitting between the resin casings.

FIG. 3 shows an example of a resin casing, and is a perspective view of a casing of a notebook computer on which resin plating is performed. FIG. 4 shows an example of a resin casing, and is an exploded front view of a casing of a mobile phone on which resin plating is performed.
For example, as shown in the notebook personal computer 1 in FIG. 3, the concave and convex portions of the resin casing are fitted to the fitting portions of the lower body case 3 and the upper body case 4, particularly the corners 5. Plating bulges are likely to occur. In addition, the hinge 7 portion of the main body case 2 and the upper lid 6 also has an uneven portion, and a bulge portion of the plating tends to occur here.

  Similarly, as shown in the mobile phone 8 of FIG. 4, a bulge portion of the plating tends to occur on the hinge 11 between the display side case 9 with a screen and the operation side case 10 with a key. In particular, since the mobile phone 8 is small and precisely designed, it may be impossible to assemble the two if there is a raised portion of the plating.

  As a means for making the plating film thickness uniform, it is easy to distribute the film thickness by configuring a single shielding plate in the plating tank as disclosed in Japanese Patent Application Laid-Open No. 2001-329400, “Plating apparatus and plating method”. A plating method that can be controlled and adjusted has been proposed.

JP 2001-329400 A

  Therefore, in order to prevent plating deposition from concentrating on the convex part of the resin casing, the resin casing is made of a synthetic resin such as vinyl chloride or metal around the convex part of the resin casing. It was surrounded by a shielding plate to suppress plating deposition on this convex part, so that it did not rise partially thick.

  Further, the plating portion of the convex portion of the resin casing that has been swelled by the resin plating treatment is cut off by polishing the portion in the post-processing step or polished to ensure the fitting performance as a resin casing. It was.

  However, in the method of plating while surrounding the convex portion of the resin casing with a shielding plate at the time of plating, there is a problem that the work process of arranging the shielding plate in the plating tank tends to be complicated work. It was.

  Moreover, in the method of cutting or polishing the plating raised portion of the convex portion of the resin casing subjected to the resin plating treatment, the plating treatment step is not only increased by one step, but also the shaving removed by post-processing. There is a possibility that the residue may adhere to the resin casing, and the cleaning work increases. In particular, the bulging portion of the uneven portion in the hinge 7 portion of the main body case 2 and the upper lid 6 of the notebook computer 1 and the bulging portion of the plating in the hinge 11 of the mobile phone 8 are precision portions. Had the problem of being prone to become long.

  Therefore, the inventors of the present invention have focused on a nickel sulfamate bath that has less protrusions than Watt bath nickel plating and has high plating uniformity. However, plating in which only the same amount of brightener, for example, saccharin or allyl sulfonate, is added to this nickel sulfamate bath in an amount of 0.5 to 3 g / L, the plating film is soft, its rigidity is low, High rigidity and hardness could not be obtained.

  The present invention has been developed to solve such problems. That is, the object of the present invention is to provide a highly rigid and high resin casing that can increase the rigidity and hardness of resin plating by using nickel sulfamate in a plating bath and performing plating treatment with high uniformity. It is to provide a hardness plating method.

  According to the present invention, a catalyst is adsorbed on a resin casing, a base metal is deposited on the resin casing in an electroless plating bath, and the resin is added to the plating bath in which an organic acid is added to a nickel sulfamate bath. There is provided a high rigidity / high hardness plating method for a resin casing, characterized in that the casing is immersed and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. The nickel sulfamate bath concentration is 300 to 600 g / L, and the organic acid content is 3 to 10 g / L. The organic acid is acetic acid.

  The resin casing is adsorbed on a resin casing, a base metal is deposited on the resin casing with an electroless plating bath, and the resin casing is immersed in a plating bath in which nickel acetate is added to a nickel sulfamate bath. Then, it can be electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. This replacing nickel acetate is preferably about twice the amount of acetic acid described above.

  In addition, a catalyst is adsorbed on a resin casing, a base metal is deposited on the resin casing in an electroless plating bath, and the resin is added in a plating bath in which an organic acid is added to a nickel sulfamate / cobalt alloy bath. The case made by immersion can be immersed and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. The nickel sulfamate bath concentration is 300 to 600 g / L, and a nickel sulfamate / cobalt alloy solution in which cobalt sulfamate is added in an amount of 10 to 15% by weight of nickel sulfamate, and the organic acid content is 3 -10 g / L. The organic acid is acetic acid.

  A catalyst is adsorbed on a resin casing, a base metal is deposited on the resin casing in an electroless plating bath, and the resin casing is placed in a plating bath in which nickel acetate is added to a nickel sulfamate / cobalt alloy bath. The body can be immersed and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. This replacing nickel acetate is preferably about twice the amount of acetic acid described above.

  The conductive plating of the resin plating is not limited to the type such as chemical nickel plating or direct plating other than chemical copper plating.

  For example, the metal casing is directly deposited on the resin casing by direct plating, and the resin casing is immersed in a plating bath in which an organic acid or nickel acetate is added to a nickel sulfamate bath or a nickel sulfamate / cobalt alloy bath. It is also possible to perform electrolytic deposition so that the nickel plating film thickness is 5 to 30 μm.

As described above, the high rigidity / high hardness plating method of the resin casing of the present invention is such that the nickel sulfamate bath deposits less than the protrusion of the plating on the resin casing than the conventional Watt bath. used. When an organic acid or an organic acid salt such as acetic acid or nickel acetate is added to the nickel sulfamate bath, the effect of lowering the plating stress and the effect of further increasing the protrusions are obtained. There is a so-called high electric part plating deposition suppressing effect. Therefore, since nickel / cobalt alloy plating is hard, high rigidity can be obtained even if the plating film thickness is reduced.
Furthermore, in the present invention, nickel / cobalt alloy plating has high plating electrodeposition stress, but the electrodeposition stress can be lowered by adding an appropriate amount of acetic acid or nickel acetate to a nickel sulfamate bath.

  As described above, the present invention uses a plating bath that has a small plating bulge on the convex portion of the resin casing. Therefore, by reducing the overall plating film thickness of the resin casing, the dimensional accuracy of the plated product is improved. You can also Therefore, since the dimensional accuracy of the resin-plated resin casing is improved and a thicker plating film can be applied, the rigidity of the plated resin-plated casing can be further increased.

  The high rigidity / high hardness plating method of the resin casing of the present invention is as follows. First, a catalyst is adsorbed on a resin casing such as a weak electrical product that requires fitting performance, and this resin casing is used in an electroless plating bath. A base metal is deposited on the substrate. In the present invention, electrolysis is performed so that the nickel plating film thickness is reduced by immersing this resin casing in a plating bath in which an organic acid or the like is added to a nickel sulfamate bath or a nickel sulfamate / cobalt alloy bath. Let it come out.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a process diagram of a high rigidity / high hardness plating method for a resin casing of the present invention. FIG. 2 is another process diagram of the high rigidity / high hardness plating method for the resin casing of the present invention.
As a molding material to be a resin casing, UMG plastic 20% CF reinforced PC / ASA (FA-440CA) was used. Of course, the high rigidity / high hardness plating method of the resin casing of the present invention is not limited to this synthetic resin.
In the present invention, a base metal is deposited on the resin casing in a surface adjustment process, an etching process, a conditioner treatment, a catalyst application process, a catalyst activation process, and an electroless plating process of the resin casing. This resin casing is immersed in a plating bath obtained by adding an organic acid to a nickel sulfamate bath, and electrolytically deposited so that the plating film thickness of the nickel becomes thin.

In the plating step, first, in order to adjust the surface of the resin molded product, it is immersed in a bath solution of placon (10 ml / L) and sulfuric acid (80 ml / L). The liquid temperature and treatment time at this time were optimally 60 ° C./6 min.
When the resin casing is a PC material such as the notebook computer 1 shown in FIG. 3, a swelling process using a solvent is performed instead of the platen. As this swelling process, there is a swell process or a solvent pre-etching process.

  In the etching step, the resin casing is immersed in a bath solution of chromic anhydride (400 g / L) and sulfuric acid (400 g / L). The optimum liquid temperature and treatment time were 65 ° C./12 min. When neutralizing chromic acid, it is immersed in a bath solution of hydrochloric acid (50 ml / L) and hydrazine sulfate (6 g / L). The optimal liquid temperature and processing time were 30 ° C./2 min.

In the conditioner treatment step, the resin casing is dipped in a bath solution of a conditioner FR concrete (10 ml / L). The optimum liquid temperature and treatment time were 40 ° C./2 min.
This conditioner treatment step can be omitted depending on the material of the resin casing.

  In the catalyst application step, a palladium / tin colloidal catalyst is adsorbed for plating deposition. In the catalyst application step and the catalyst activation step, a catalyst is added for the purpose of promoting the chemical reaction (reduction action) of copper and nickel metal ions in the electroless plating bath.

  In the electroless plating process, the resin casing to which the catalyst is added is immersed in a chemical plating bath, metal ions are reduced, and the base metal is deposited. As this chemical plating bath, a citric acid / ammonia chelate chemical nickel plating solution was used, and the nickel concentration in the bath was 4.5 to 6.7 g / L. The bath temperature and treatment time were optimally 38 ° C./8 min. Furthermore, the conductive plating of the resin casing is not limited to such a chemical plating method, and a direct plating method in which a metal is directly deposited on the resin casing can also be employed. For example, it can be plated by the plating method of the present invention on a resin casing on which a copper electroplating treatment of about several μm on the resin.

  In the next electroplating step, the resin casing is immersed in a plating bath obtained by adding an organic acid to a nickel sulfamate bath and subjected to electrolytic treatment. At this time, the concentration of the nickel sulfamate bath was optimally 500 g / L. Acetic acid is added as an organic acid to the nickel sulfamate bath. The acetic acid content was optimally 7.2 g / L. The bath temperature and treatment time were optimally 45 ° C./72 min. This completes the resin plating. It is also possible to add nickel acetate instead of acetic acid. In the present invention, by adding acetic acid or nickel acetate to the nickel sulfamate bath, there is an effect of lowering the plating stress and an effect of further reducing the bulge of the convex part (high electric part plating precipitation suppressing effect).

  As the hardness of the plating obtained by the high-rigidity / high-hardness plating method of the present invention, the plating film when plated with a nickel sulfamate plating bath had a Hv of 280 to 350.

  A nickel sulfamate / cobalt alloy bath can be used instead of the nickel sulfamate bath. The concentration of the nickel sulfamate / cobalt alloy bath is 300 to 600 g / L for nickel sulfamate and 30 to 60 g / L for cobalt sulfamate. The optimum content of organic acid was 3 to 10 g / L. The bath temperature and treatment time were optimally 45 ° C./60 min. In addition, acetic acid or nickel acetate can be added as an organic acid.

  The nickel plating film thickness is electrolytically deposited so as to be 20 to 25 μm. When this is nickel-plated in a nickel sulfamate bath, a plating process in which the protrusion of the convex portion of the resin casing is less prominent can be performed without reducing the dimensional accuracy of the resin casing. As described above, since the dimensional accuracy of the resin casing is improved, a thick plating film can be applied, so that the rigidity of the plated resin casing can be increased.

  The plating hardness obtained by the high rigidity / high hardness plating method of the present invention was Hv 430 to 470 when the plating film was plated with a nickel sulfamate / cobalt alloy bath. High hardness was able to be obtained compared with the nickel sulfamate bath mentioned above. Therefore, since nickel / cobalt alloy plating is hard, high rigidity can be obtained even if the plating film thickness is reduced. Nickel-cobalt alloy plating has high plating electrodeposition stress, but the electrodeposition stress can be lowered by adding an appropriate amount of acetic acid or nickel acetate to a nickel sulfamate bath.

  In addition, this invention is not limited to embodiment of the invention mentioned above, A plating process with few plating bulging of the convex part of a resin-made housing | casing can be performed using a nickel sulfamate bath or a nickel sulfamate-cobalt alloy bath. As long as it is a method that can improve the dimensional accuracy of the resin casing and increase its rigidity, it is not limited to the configuration shown in the illustrated process or processing method, and various methods are possible without departing from the scope of the present invention. Of course, it can be changed.

  The high rigidity / high hardness plating method of the resin casing of the present invention can perform metal plating on the resin casing of other weak electrical appliances such as a mobile phone and a notebook personal computer that require high rigidity.

It is process drawing of the high rigidity and high hardness plating method of the resin-made housing | casing of this invention. It is another process drawing of the high rigidity and high hardness plating method of the resin casing of the present invention. It is an example of a resin case and is a perspective view of a case of a notebook computer on which resin plating is performed. It is an exploded front view of the case of the mobile phone which shows an example of resin cases and performs resin plating.

Explanation of symbols

1 Notebook PC (resin casing)
2 Main body case 3 Lower main body case 4 Upper main body case 5 Corner portion 6 Upper lid 7 Hinge 8 Mobile phone (resin casing)
9 Display side case 10 Operation side case 11 Hinge

Claims (11)

Adsorb the catalyst to the resin casing, deposit the base metal on the resin casing with an electroless plating bath,
A resin characterized in that the resin casing is immersed in a plating bath obtained by adding an organic acid to a nickel sulfamate bath and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. High-rigidity and high-hardness plating method for chassis. 2. The high rigidity / high hardness plating of the resin casing according to claim 1, wherein the nickel sulfamate bath concentration is 300 to 600 g / L, and the content of the organic acid is 3 to 10 g / L. Method. 3. The method for plating a resin case with high rigidity and high hardness according to claim 1 or 2, wherein the organic acid is acetic acid. Adsorb the catalyst to the resin casing, deposit the base metal on the resin casing with an electroless plating bath,
A resin characterized in that the resin casing is immersed in a plating bath obtained by adding nickel acetate to a nickel sulfamate bath and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. High-rigidity and high-hardness plating method for chassis. Adsorb the catalyst to the resin casing, deposit the base metal on the resin casing in the electroless plating bath,
The resin casing is immersed in a plating bath obtained by adding an organic acid to a nickel sulfamate / cobalt alloy bath and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. High-rigidity and high-hardness plating method for resin casings. The nickel sulfamate bath concentration is 300 to 600 g / L, and a nickel sulfamate / cobalt alloy solution in which cobalt sulfamate is added in an amount of 10 to 15% by weight of nickel sulfamate, and the organic acid content is 3 The high-rigidity / high-hardness plating method for a resin casing according to claim 5, wherein the plating method is 10 g / L. The method for plating a resin case according to claim 5 or 6, wherein the organic acid is acetic acid. Adsorb the catalyst to the resin casing, deposit the base metal on the resin casing in the electroless plating bath,
The resin casing is immersed in a plating bath obtained by adding nickel acetate to a nickel sulfamate / cobalt alloy bath and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. High-rigidity and high-hardness plating method for resin casings. The high-rigidity / high-hardness plating method for a resin casing according to claim 1, wherein the electroless plating is chemical copper plating. Deposit metal directly on the resin casing,
A resin characterized in that the resin casing is immersed in a plating bath obtained by adding an organic acid to a nickel sulfamate bath and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. High-rigidity and high-hardness plating method for chassis. Deposit metal directly on the resin casing,
The resin casing is immersed in a plating bath obtained by adding an organic acid to a nickel sulfamate / cobalt alloy bath and electrolytically deposited so that the nickel plating film thickness is 5 to 30 μm. High-rigidity and high-hardness plating method for resin casings.

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