JPH11209879A - Workpiece plating method - Google Patents

Abstract

[PROBLEMS] To provide a plating method capable of forming a plating film having excellent adhesion on a work containing a metal material, a non-conductive material and at least one of carbon. SOLUTION: (1) A step of performing a neutral colloidal palladium treatment on a work including a metal material, a non-conductive material and at least one of carbon, a step of performing a plating treatment,
Plating method for workpieces consisting of (2) metal materials,
A plating method for a work, comprising a step of performing a zinc substitution treatment on a work containing a non-conductive material and at least one of carbon, a step of performing a neutral colloidal palladium treatment, and a step of performing a plating treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for plating a work containing a metal material, a non-conductive material and at least one of carbon.

[0002]

2. Description of the Related Art In some cases, a workpiece is subjected to a zinc substitution treatment or an acidic palladium treatment before plating. The zinc substitution treatment is mainly performed when the work is made of aluminum, magnesium, or an alloy thereof. These workpieces tend to form an oxide film on the surface, and the oxide film hinders the adhesion to the plating film and lowers the adhesion. For this reason, it is known that plating is performed after replacing the work surface with zinc to enhance the adhesion between the work and the plating film. The acidic palladium treatment is performed when the work is made of a non-conductive material such as ceramics or a material such as carbon that is difficult to be plated. Plating treatment (electroless plating or electrolytic plating) is an effective method of forming a plating film on conductive materials, but cannot be applied to non-conductive materials.
It has been known that an acidic palladium treatment is performed before plating to impart conductivity to a work surface. Also, it is known that carbon or the like which is difficult to be plated is easily plated by acidic palladium treatment.

[0003]

However, a plating treatment is performed on a work containing both a metal material and a ceramic material, for example, a work made of an Al-based composite material or a work obtained by combining an independent Al (alloy) member and a ceramic member. If you do
When a conventionally known zinc substitution process is applied, no plating film is formed on the ceramic material portion of the work. Further, when the acid palladium treatment is applied, the plating film is formed on almost the entire surface of the work, but there is a problem that the adhesion between the work and the plating film is low because the Al material in the work is dissolved in the acidic palladium solution. An object of the present invention is to provide a plating method capable of forming a plating film having high adhesion on a work containing a metal material, a non-conductive material and at least one of carbon.

[0004]

The present invention to achieve the above object is as follows. (1) A plating method for a work, comprising a step of performing a neutral colloidal palladium treatment on a work including a metal material, a non-conductive material and at least one of carbon, and a step of performing a plating treatment. (2) a step of performing a zinc substitution treatment on a work containing a metal material, a non-conductive material and at least one of carbon, a step of performing a neutral colloidal palladium treatment, and a step of performing a plating treatment. Plating method for work.

In the above method (1), a neutral colloidal material that does not dissolve the metal on the surface of the work before plating the work containing a metal material, a non-conductive material and at least one of carbon. Since the palladium treatment is performed, it is possible to form a plating film having excellent adhesion to a work. The above (2)
In the method of (1), the zinc-substituted treatment and the neutral colloidal palladium treatment are performed before the plating treatment is performed on the work including the metal material, the non-conductive material, and at least one of carbon. Thus, a plating film having better adhesion to a work than a plating film obtained by the method can be formed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described.
The plating method according to the first embodiment of the present invention includes a step of performing a neutral palladium treatment on a work including a metal material, a non-conductive material and at least one of carbon, and a step of performing a plating treatment. Examples of a work including a metal material, a non-conductive material, and at least one of carbon include a work made of a metal-based composite material. The metal matrix composite comprises a matrix and a reinforcement. The base material is a metal that easily dissolves in acidic liquid,
For example, aluminum, aluminum alloys, magnesium, magnesium alloys, copper, copper alloys, iron, iron alloys and the like are used, and for the reinforcing material, for example, silicon carbide, alumina,
Non-conductive materials such as ceramics such as zirconia and carbon are used. The neutral colloidal palladium treatment is performed by immersing the work in a neutral colloidal palladium aqueous solution. In the neutral colloidal palladium aqueous solution (pH 5 to pH 9), for example, an adsorbing organic substance (tertiary amine polymer and / or quaternary ammonium polymer) is reduced to a palladium metal colloid (metal reduced to metal) adsorbed therearound. Is used. By performing the neutral colloidal palladium treatment before the plating treatment, a plating film is formed also on a non-conductive material portion, and a plating film is easily formed even on a portion where a plating film such as carbon hardly adheres. The plating is electroless plating, and for example, nickel plating, copper plating, tin plating, gold plating, silver plating, palladium plating, etc. are performed according to the application.

In FIG. 1, SiC is converted to silica sol (SiO
₍₂ sol) and a molded body fired in an air atmosphere at 800 ° C. in a mold, impregnated with an Al alloy by high-pressure casting, and cast a cast material (for example, Al alloy: SiC = 40: 60 (vol. %)), Processed into a test piece having a length of 40 mm, a width of 20 mm and a thickness of 3 mm, subjected to an appropriate surface cleaning, immersed in a neutral colloidal palladium solution for about 1 to 2 minutes, washed with water, and nickel-plated. The result of measuring the adhesion strength of the plated film formed after the treatment to the test piece is shown as Test Example 1. In addition, a plating film was formed on the entire surface of the test piece over the Al alloy portion and the SiC portion. For comparison, the same test piece as that used in Test Example 1 was treated in the same manner as in Test Example 1 except that the test piece was immersed in an acidic palladium solution instead of a neutral colloidal palladium solution. The result of measuring the adhesion strength of the formed plating film to the test piece is shown as Comparative Example 1 in FIG. The adhesion strength was measured by a soldering tensile test method (a copper bar was soldered to a test piece on which a plating film was formed and a tensile force was applied between the test piece and the copper bar).

[0008] Comparing the adhesion strength of the plating film to the test piece of Test Example 1 and Comparative Example 1, Test Example 1 has a higher adhesion strength. Therefore, when forming a plating film on a work made of an Al-based composite material, by performing a neutral colloidal palladium treatment and then performing a plating treatment, a plating film is formed on the entire surface of the work and performing an acidic palladium treatment. As a result, a plating film having higher adhesion can be obtained. Since the Al alloy in the Al-based composite material dissolves in the acidic palladium treatment solution, the Al alloy in the Al-based composite material does not dissolve in the neutral colloidal palladium aqueous solution, so that the plating film and the workpiece have high Adhesion is obtained. Also, when performing neutral colloidal palladium treatment on multiple workpieces,
Since the neutralized colloidal palladium treatment liquid does not deteriorate due to the dissolution of the Al alloy, the same liquid can be used repeatedly, resulting in excellent productivity.

Next, a second embodiment of the present invention will be described.
The plating method according to the second embodiment of the present invention is different from the first embodiment in that a step of performing a zinc substitution treatment before applying a neutral colloidal palladium treatment is added. Note that the zinc substitution treatment is generally performed using a zinc zincate bath in which zinc is dissolved in a strongly alkaline solution such as sodium hydroxide or potassium hydroxide, and after activating the work surface by etching and pickling. A zinc alloy bath in which a small amount of iron or nickel is mixed with a complexing agent in a zinc zincate bath may be used. In the plating method according to the second embodiment of the present invention, in particular, a metal in which a work is easily dissolved in an acidic liquid and an oxide film is easily formed on the surface, for example, aluminum, aluminum alloy, magnesium, magnesium alloy, copper, copper alloy In such a case, a plating film having excellent adhesion to a workpiece can be obtained.

In FIG. 1, the same test piece as the test piece used in Test Example 1 is subjected to etching, pickling, and zinc substitution, and then the same processing as that performed to the test piece in Test Example 1 is performed. The result of measuring the adhesion strength of the plated film thus formed is shown as Test Example 2. The adhesion strength was measured by the soldering tensile test method as in Test Example 1. The plating film had a high adhesive strength equal to or higher than the solder strength, and the solder cracked during the tensile test.

[0011] Comparing the adhesion strength of the plating films of Test Example 1 and Test Example 2 to the test piece, Test Example 2 has higher adhesion strength. Therefore, when a plating film is formed on a work made of an Al-based composite material, a neutral colloidal palladium treatment is performed after performing a zinc substitution treatment to replace an oxide film formed on the work surface with zinc. It can be seen that a plating film having higher adhesion can be obtained as compared with the case where the colloidal palladium treatment is performed alone.

FIG. 1 shows that the base material was M
g. A test piece made of a Mg-based composite material whose reinforcing material is ZrO ₂ is subjected to plating treatment in the same manner as the plating method shown in Test Example 2 to reduce the adhesion strength of the formed plating film. The result of the measurement is shown. The plating film was formed on the entire test piece. Test Example 3 shows that a plating film having high adhesion can be formed by the plating method of the embodiment of the present invention even on a work made of an Mg-based composite material.

In Test Examples 1 to 3, the case where the entire test piece is made of a metal-based composite material is taken as an example. However, a test piece in which a part is made of a metal-based composite material and the remainder is made of a metal material is also used. By performing the plating treatment shown in the first and second embodiments of the present invention, a plating film having excellent adhesion can be easily obtained on the entire surface of the test piece. Specifically, after high-pressure casting was performed in the same manner as in Test Example 1, an aluminum alloy portion was intentionally cut out from the cast material, and a portion was partially formed of an Al / SiC composite material as shown in FIG. A test piece made of only an Al alloy material was prepared, plated in the same manner as in Test Example 2, and the adhesion strength of the formed plating film was measured. The adhesion strength of the plating film depends on the test piece A
Both the plating film formed on the alloy material and the plating film formed on the composite material were measured. As a result, the adhesion strength of the plating film formed on the Al alloy material was high as shown in Test Example 4 in FIG. 1, and the adhesion strength of the plating film formed on the composite material was higher than that of Test Example 2 in FIG. This is the same, and it can be seen that a plating film having excellent adhesion is formed on the entire surface of the test piece. Also, by applying the plating treatment of the embodiment of the present invention to a work in which a metal material and a non-conductive material (for example, a ceramic material) are combined, a plating film having excellent adhesion can be easily formed on the entire surface of the work. Is obtained.

[0014]

According to the plating method of the first aspect, it is possible to obtain a plating film having high adhesion to a work containing a metal material, a non-conductive material and at least one of carbon. According to the plating method of the second aspect, the adhesion between the metal material and the work containing at least one of the non-conductive material and carbon is higher than the plating film obtained by the plating method of the first aspect. A plating film is obtained.

[Brief description of the drawings]

FIG. 1 is a graph showing the adhesion strength of a plating film to a test piece according to all examples of the present invention.

FIG. 2 is a schematic view of a test piece used in Test Example 4 according to the embodiment of the present invention.

Claims (2)

[Claims] 1. A method of plating a work, comprising: a step of performing a neutral colloidal palladium treatment on a work including a metal material, a non-conductive material and at least one of carbon; and a step of performing a plating treatment. . 2. A step of performing a zinc substitution treatment on a work including a metal material, a non-conductive material and at least one of carbon, a step of performing a neutral colloidal palladium treatment, a step of performing a plating treatment, Plating method for workpieces consisting of