Stripping solution and stripping method for copper-based palladium-nickel alloy coating stripping

Abstract

The invention discloses deplating liquid and a deplating method for deplating a copper base palladium-nickel alloy plating layer. The deplating liquid is obtained by homogenizing 45-55 parts of bromide, 6-10 parts of oxidant, 0.3-0.6 part of corrosion inhibitor-benzotriazole and 40-60 parts of water; the pH value of the deplating liquid is less than 4; the bromide is one or a composition of two of hydrobromic acid and sodium bromide; and the oxidant is two or compositions of more than two of hydrogen peroxide water solution, manganese dioxide, sodium bromate and high sodium bromate. A bromination method is adopted to remove the palladium-nickel alloy plating layer on a copper matrix; the plating layer is deplated thoroughly and efficiently; the process is simple; the corrosion of the copper matrix is slight; the separation of the copper matrix and the palladium-nickel alloy plating layer in the plating part is realized, that is, the deplating of the copper base palladium-nickel alloy plating layer is realized; and after the deplating liquid is saturated, patalldium and nickel can be recovered therefrom.

Description

technical field [0001] The invention relates to a chemical deplating method, in particular to a deplating solution and a deplating method for copper-based palladium-nickel alloy coating deplating. Background technique [0002] Palladium is an excellent electrical contact material (resistivity of 0.099Ωmm / m). In the electronics industry, due to its good corrosion resistance, wear resistance, solderability and low contact resistance, palladium-nickel plating has been used in many areas instead of gold plating, such as metal packaging, integrated circuit lead frames and connectors, etc. plating. [0003] Palladium standard potential E Pd 2+ / Pd θ It is +0.82V, its chemical properties are stable, insoluble in cold sulfuric acid and hydrochloric acid, soluble in nitric acid, aqua regia and molten alkali, not corroded by sulfide, and can maintain bright color for a long time. Both palladium and copper have a face-centered equiaxed structure, and their atomic radii are also s...

AI Technical Summary

Problems solved by technology

The disadvantage of this process is that a large amount of concentrated sulfuric acid and concentrated nitric acid are used, which requires high equipment, and the production process is very dangerous; the copper substrate after deplating needs to be cleaned with water quickly after being taken out, and the heat release further promotes the Copper dissolves and releases a large amount of brown nitrogen oxide gas, and at the same time, the amount of cleaning water is relatively large; in addition, when the sulfur nitric acid mixed acid deplating solution is diluted, heat will be generated to generate gas, and the entire process will produce a large amount of difficult-to-treat acidic copper-containing wastewater