A kind of method of single-pulse cyanide-free electroplating silver

Abstract

The invention discloses components and a technology of a monopulse cyanide-free silver electroplating solution. The components and the technology are characterized in that: cyanide-free silver electroplating solution mainly comprises silver nitrate, hydantoin and derivatives thereof, potassium pyrophosphate, potassium sulfate, hydrochloric acid, deionized water, and the like. Operation conditions are that the pH value of the electroplating solution is 6-10 and that the temperature of the electroplating solution is 20-40 DEG C. A finely crystallized silver plating can be obtained through electroplating on pure copper or a copper alloy by utilizing of monopulse electroplating and by controlling the pulse width, the pulse duty cycle, the average pulse current density and the pulse working time. The electroplating solution is simple in formula, easy to control, strong in throwing power and in covering power and high in batch production stability. The plating is finely crystallized, and is good in appearance color. The plating is free from peeling, falling off and stripping. The technology can replace cyanide silver electroplating technologies, is environmental-friendly and pollution-free, and reduces damage of silver electroplating to operators.

Description

technical field

[0001] The invention belongs to the technical field of electroplating chemistry, and in particular relates to a cyanide-free electroplating silver solution and a silver plating method. Background technique

[0002] Metal silver plating has good electrical conductivity, weldability and low contact resistance. It is widely used in appearance decoration, electronic devices, transformers, and valuable instruments and meters. The current market is mainly based on cyanide silver plating process, which pollutes the environment and harms the environment. damage to the health of the operator. The cyanide-free silver plating solution uses cyanide-free ions as silver ion complexing agents to deposit silver plating layers through electrochemical reactions. However, due to the performance of the coating cannot meet the process requirements, poor stability, poor bonding and other problems, cyanide-free silver plating has not been widely used in the electroplating banking ...