JPH0277596A - Method for plating copper or copper alloy - Google Patents

Abstract

PURPOSE:To easily activate the surface of a Cu material and to obtain a high quality plated material by successively subjecting the Cu material to degreasing, pickling with a sulfuric acid soln. contg. Cu ions and electroplating. CONSTITUTION:A Cu or Cu alloy material is degreased, immersed in a pickling soln. contg. 5-40g/l Cu ions and 30-300g/l sulfuric acid, taken out and washed. The surface-activated material is immediately electroplated with a metal such as Ni, Cu, Sn, Au or Ag. This plated Cu or Cu alloy product has satisfactory wettability with solder at the time of soldering.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a pretreatment method for electroplating copper or a copper alloy with a metal such as nickel, copper, tin, gold, or silver.

[Prior Art] Copper or copper alloy plates, strips, pressed products, etc. are electroplated using a continuous line, a rack line, a barrel line, or the like, depending on their shape. In these lines, as a pretreatment for plating, it is customary to perform a degreasing process using an alkaline solution to remove oily stains such as rolling oil and press oil that adhered to the material in the previous process. Then, it is washed with water and further activated with an acidic solution. This acid activation treatment is usually performed with an aqueous solution containing sulfuric acid or hydrochloric acid as a main component. In addition, when the degree of oxidation film on the material surface is significant, or when the surface texture is not suitable for plating (such as when the roughness is too large), sulfuric acid,
It is customary to chemically polish the material using a hydrogen peroxide polishing solution, Kirin's solution, or the like.

[Problems to be Solved by the Invention] However, although chemical polishing treatment has an excellent material surface conditioning effect as a pre-plating treatment, it is expensive and complicated in terms of management.

[Means for Solving the Problems] The present invention provides copper or copper alloy materials with copper ions after degreasing.
This is a method for plating copper or copper alloy, which comprises electroplating after pickling with a pickling solution containing 40 g/I and 30 to 300 g/I of sulfuric acid.

In the pickling treatment of the present invention, copper ions are added to the sulfuric acid, so that the effect on the oxidized film of the material is much stronger than in the case of sulfuric acid alone. However, if the copper ion concentration is less than 5g/1, the activation effect will not be sufficient.
, the activation effect is saturated at about 40 g/l. The active effect becomes stronger when the sulfuric acid concentration exceeds 30g/I, and 300g
/I, and use at concentrations exceeding this is uneconomical.

The ratio of copper ions to sulfuric acid is appropriately selected within a range equal to or less than the solubility of copper ions. There are no particular restrictions on temperature and time, but the higher the temperature, the stronger the activation effect.

[Example] Next, examples and comparative examples will be described.

Example thickness 0.311I11 phosphor bronze (Cu-8vL%S
n-〇, 1 vL%P) plate with Na OH 100g/l
The sample was immersed in a degreasing solution containing 10 g/l of surfactant for 2 minutes and then washed with water.

Furthermore, Cu'°aog/l, H2S O4100g/
The sample was immersed in a pickling solution having a composition of 1 for 20 seconds and then washed with water. Immediately put in a sulfuric acid bath (S n ''' 30g/l, H2S04100
g/l, surfactant 10g/1I11. Brightener 5g/I
) was used to electroplate 2 μm of tin. When this tin-plated product was subjected to a soldering test specified in MILSTD-202E-208C, it showed good wettability.

Comparative Example When a tin-plated product was prepared in the same manner as in the example except that the acid solution was 100 g/I of H2SO4 and subjected to the same soldering test, solder repellency was observed on a part of the solder-immersed surface.

[Effects of the Invention] According to the present invention, in the pre-plating treatment of copper or copper alloy, the surface of the material that cannot be activated by ordinary pickling with sulfuric acid etc. can be treated at a lower cost than by chemical polishing treatment, and at a lower cost than the chemical polishing treatment. can be activated to obtain a plating material of good quality.

Claims (1)

[Claims] After degreasing copper or copper alloy material, add 5 to 40 g of copper ions/
1. A method for plating copper or copper alloy, which comprises electroplating after pickling with a pickling solution containing 30 to 300 g/l of sulfuric acid.