In recent years, tin plating technology has been rapidly promoted in the electronics industry, and people's requirements for the welding performance of workpieces are becoming increasingly high. In the production process of using tin plating additives, some workpieces have poor welding performance of the tin plating layer, which greatly increases the failure rate due to welding quality issues. So what factors affect the welding performance of the coating?
Bigely Technology has conducted an analysis based on on-site experience and product characteristics, mainly focusing on the following five points:
1.Excessive amount of tin plating brightener. When there is an excess of brightener in the plating solution, polarization will be enhanced, and there will be a large amount of hydrogen evolution during the electroplating process. And Sn4+in the plating solution hydrolyzes into tin acid, which forms colloids with the decomposition products of the brightener, making the plating solution turbid and reducing the current efficiency of the cathode. The coating is prone to organic impurities, leading to a decrease in welding performance.
2.Excessive Fe2+ions in the plating solution. Fe2+in the plating solution will be oxidized to Fe3+, and the oxidizing property of Fe3+will oxidize Sn2+to Sn4+. The hydrolysis of Sn4+forms a gel structure with Sn2+and organic compounds, causing the plating solution to become turbid and affecting the welding performance of the coating.
3.The temperature of the plating solution is relatively high. High temperature of the plating solution will accelerate the hydrolysis of Sn4+, resulting in a deterioration of the plating solution state and affecting the welding performance of the coating.
4.The coating thickness is too thin. Due to tin plating on copper or steel substrates after copper plating, tin will interpenetrate with copper to form an alloy diffusion layer. When the coating is too thin or uneven in thickness, it will affect the welding performance of the coating.
5.The workpiece has been placed for a long time. The welding performance of the newly produced workpiece coating is very good, but after being left for a long time (about 2 months), the weldability of the coating will deteriorate, mainly due to the oxidation of the workpiece surface in the air.
Therefore, when using tin plating additives for production, we should pay attention to the above 5 factors that affect the welding performance of the workpiece coating, and strengthen the maintenance and management of the plating solution to reduce the losses caused by poor welding performance of the workpiece coating. If you are interested in tin plating additives, please contact Bigley customer service for free samples and detailed technical information!
