Cyanide-free copper electroplating solution

Abstract

The invention provides cyanide-free copper electroplating solution. The electroplating solution is prepared from the following components by concentration: 0.2 to 15 g / L of grain refiner, 0.3 to 80 g / L of fast forming agent, 40 to 60 g / L of copper sulfate, 80 to 180 g / L of hydantoin, and 20 to 40 g / L of citric acid, wherein the refiner is prepared from the following components in parts by weight: 0.1 to 10 parts of thiourea modified derivative and 0.1 to 5 parts of bismuth nitrate; and the fast forming agent is prepared from the following components in parts by weight: 0.1 to 10 parts of polyethylene glycol, 0.1 to 30 parts of malic acid and 0.1 to 40 parts of sodium succinate. The electroplating solution is very stable, high in current efficiency and good in dispersing capacity and covering power; the current efficiency of the electroplating solution is higher than that of a cyanide electroplating solution and can reach 50 to 70 percent; the refining size of crystal grains reaches 20nm to 80nm and is one third to half of the refining size of the cyanide electroplating, a coating is uniform, and the softness is good; and the electroplating solution is a cyanide-free formula, the potential risk of personnel safety accidents of the cyanide is eliminated, and the environmental pollution is greatly reduced.

Description

technical field [0001] The invention relates to the field of electroplating, in particular to a cyanide-free copper plating electroplating solution. Background technique [0002] The dispersion ability of cyanide plating is better, but cyanide is a highly toxic chemical. Therefore, the pollution of this bad liquid to the environment is very serious. In order to replace the highly toxic cyanide, from the 1970s Since then, a large number of problems have been tackled domestically, but a complex that is both non-toxic and possesses the complexation, passivation and surface activity of cyanide has not been found so far. Alkaline copper plating in the cyanide-free copper plating process is currently widely used, but it is still immature on the whole. The main reason is that the maintenance of the bath is still relatively difficult, the current efficiency of the plating solution is not high, and the crystallization of the plating layer is not fine enough. Slow, low brightness, po...

AI Technical Summary

Problems solved by technology

[0002] The dispersion ability of cyanide plating is better, but cyanide is a highly toxic chemical. Therefore, the pollution of this bad liquid to the environment is very serious. In order to replace the highly toxic cyanide, from the 1970s Since then, a large number of domestic researches have been carried out, but a complex compound that is both non-toxic and has both complexation, passivation and surface activity of cyanide has not yet been found.

Alkaline copper plating in the cyanide-free copper plating process is currently widely used, but it is still immature on the whole. The main reason is that the maintenance of the bath is still relatively difficult, the current efficiency of the plating solution is not high, and the crystallization of the plating layer is not fine enough. Slow, low brightness, poor softness and other problems

[0003] Therefore, in order to solve the existing technical problems of slow light emission speed, low brightness, low current efficiency of the plating solution, and low softness of the plating layer in the existing cyanide-free copper plating, it is necessary to develop a thinner grain size and rapid light emission. Cyanide-free copper plating electroplating solution, improve the stability, dispersion ability and covering ability of the electroplating solution, improve the current efficiency of the plating solution, so as to obtain a flexible coating

Images