Lead-free Pure Tin Plating Coating Color Control Process And Electroplating Automation

Lead-free pure tin plating is widely used in electronic devices pin plating, the process mainly because of the introduction of increasingly stringent restrictions on the world lead in the application of electronic products, lead-free pure tin plating with low cost, bath composition is simple, easy operation and maintenance, easy to apply promotion, at home and abroad more and more companies to use pure tin plating to replace tin-lead plating. However, there is lead-free crystal of pure tin plating tin whisker coating easy to change color, easy to muddy the bath and so on, these issues will cause trouble and distress to the enterprise, serious it will bring enormous economic losses.This thesis focuses on lead-free pure tin plating coating color easily to study the issue, the use of electrochemical, chemical methods, to lead-free pure tin plating as the main object of study, the mechanism of discoloration in the coating, based on in-depth analysis of possible coating color of the various factors and methods to verify by testing them on the coat color of the degree of control in order to find lead-free pure tin plating coating easy to color response.In the study, lead-free pure tin plating and coating process and the mechanism of discoloration of the system's introduction, in order to solve the color coating provides a theoretical basis. Plating and coating process based on the mechanism of discoloration, this thesis through a large number of experimental data, a detailed study of the process before plating treatment, plating, coating color post-processing on the effect of plating additives also studied the influence of the coating color.This thesis has found the factors that affect the coating color, based on tests given by the corresponding control measures to prevent the occurrence of lead-free pure tin plating. Through this study, the actual production through large-scale validation, has been able to protect storage conditions at room temperature, no significant color change within the next year, after the two-24H 85% test no significant discoloration.Finally, in order to protect the color coating the effectiveness of control measures, in order to improve the automated electroplating production, this paper designed a set of automatic electroplating production line control system. Validation through large-scale production, the system can better control plating process greatly improves production efficiency and plating process control level...