JPH03188283A - Sealing method for gold-plated materials - Google Patents

Abstract

PURPOSE:To sufficiently seal the pinhole parts of a gold plated material and to improve the corrosion resistance and wear resistance of the material by subjecting the surface of the blank material applied with gold or gold alloy plating to a pickling treatment as a pretreatment, then to a hole sealing treatment. CONSTITUTION:The blank material applied with the gold or gold alloy plating is immersed into a treating liquid, such as an org. amine, then the surface thereof is subjected to the hole sealing treatment. The above-mentioned blank material is subjected to the pickling treatment as the pretreatment at this time. Any acids, such as nitric acid, hydrochloric acid and sulfuric acid, which activate the underlying metal, may be used as the acid used therein. The reactivity and adsorptivity between the substrate in the pinhole parts and the hole sealing liquid are improved by this treatment, by which the pinhole parts are sufficiently sealed. The gold plated material having the excellent corrosion resistance and wear resistance is obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for sealing the surface of a material plated with gold or gold alloy.

[Conventional technology] In order to ensure contact reliability at contact parts such as connectors,
It is decorated with gold plating, etc. However, in recent years, the plating thickness has been increasingly reduced in order to reduce costs. When the thickness of gold plating is reduced, many pinholes occur in the plating layer,
Corrosion of the underlying plating (generally Ni) begins from pinholes, so it is necessary to seal the pinholes by some method to suppress corrosion. Gold plating for connectors is also required to have wear resistance. Therefore, it is common to perform a sealing treatment to improve corrosion resistance and abrasion resistance. Conventional pore sealing treatment is performed by immersing the gold-plated material in a treatment liquid of organic amine, wax, mercaptan, octadecane derivative, or the like.

[Problems to be solved by the invention] In conventional hole sealing treatment, the treatment liquid often does not penetrate into the pinhole, and the pinhole is not sufficiently sealed.
There was a problem in that the corrosion resistance of the pinhole portion was poor.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors conducted extensive research and found that corrosion resistance and wear resistance can be improved by sufficiently sealing the pinhole portions of the gold-plated material. It was discovered that this could be further improved, leading to the present invention.

That is, the present invention is a patented method for sealing a material, which is characterized in that pickling is performed as a pretreatment when sealing the surface of a material plated with gold or gold alloy.

To explain the present invention specifically, first, materials to which the present invention is applied include metals or synthetic resins that can be plated with gold such as copper or copper alloys, steel or stainless steel;
It can also be applied to organic or inorganic materials such as ceramics coated with metal, or to metal deposited by electroless plating or the like and then gold plated thereon. Gold plating is performed by electroplating, electroless plating, vapor deposition, sputtering, etc. The gold-plated material for sealing can be applied to all shapes such as strips, blocks, terminals, etc., and is not particularly limited. Furthermore, the pore sealing liquid is a known technique such as the above-mentioned organic amine, wax,
Any treatment with mercaptan, octadecane derivatives, etc. can be carried out, and no specific treatment is prescribed. Furthermore, the thickness of the gold plating used when performing the sealing treatment is selected to be an economical thickness suitable for each application so that the underlying surface is not exposed. - For example, when gold plating is done by electroplating, at least 0.05
The thickness is required to be at least .mu.m, preferably at least 0.1 .mu.m.

In particular, by acid-pickling the gold-plated material before sealing it, the underlying metal of the pinhole is activated, resulting in better reactivity between the layer and the underlying layer compared to dip coating alone. Moreover, it exhibits sufficient pore-sealing properties and is characterized by improved corrosion resistance.

The sealing method does not specify a specific sealing method.

Further, the acid used may be any acid that activates the base metal, and any acid such as nitric acid, hydrochloric acid, sulfuric acid, etc. can be used, and a specific liquid is not specified.

[Example] Before immersing the gold-plated strip in a solution in which each sealing solution shown in Table 1 was dissolved in 1.1.1-trichloroethane to a predetermined concentration, it was immersed in a 1Ovo 1% sulfuric acid solution.・Processed. A sample without pretreatment was used as a comparative example. Soaking 6
After 0 seconds, it was air-dried at room temperature, and the following test was performed.

(1) Corrosion resistance test Gold-plated material coated with a sealing agent is 5O2X LOpp
a+X 40°C x 65 hours x 90% or more of relative temperature.

(2) Contact resistance After the corrosion resistance test, the maximum value of contact resistance (r+
-200, load 10g).

The test results are shown in Table 1. As is clear from these results, it can be seen that the examples of the present invention have significantly excellent corrosion resistance.

[Effects of the Invention] As explained above, by performing pickling treatment before sealing the surface of the material plated with gold or gold alloy of the present invention, the base material and the sealing in the pinhole area can be removed. The treatment solution has excellent reactivity and adsorption properties, and a gold or gold alloy plated material with excellent corrosion resistance and wear resistance can be obtained.

Claims (1)

[Claims] A method for sealing a gold-plated material, which comprises carrying out pickling treatment as a pretreatment when performing sealing treatment on the surface of a material plated with gold or gold alloy.