In the production process of using acid tinning brightener, sometimes pinholes and streaks appear on the surface of the workpiece coating. What is the reason?
According to the site experience and the characteristics of the acid tinning brightener Sn-807, Bigolly Technology analyzed the following three reasons:
1. Excessive brightener.If the brightener in the acidic tin plating bath is excessive, the cathode polarization of the bath will increase, the cathode current efficiency will decrease, and the blisters produced on the surface of the workpiece will increase, so that the coating surface will appear pinhole or air streaks after adsorption.Therefore, the brightener can be supplemented according to Hull cell test or current consumption, and the plating solution can be treated with 1~3g/L activated carbon regularly.
2. The plating solution is not stirred enough.In order to prevent the oxidation of stannous in acid tin plating bath, air stirring cannot be used.When the bath is agitated or the cathode moves slowly, the bubbles generated during tin plating will not be fixed on the surface of the workpiece, resulting in pinhole or air streaks.Therefore, in the production process, we should control the speed of workpiece agitation or cathode movement. Generally, the cathode movement should be controlled at about 30 times/minute.
3. There are too many organic impurities in the plating solution.When there are many organic impurities in the plating solution, the color of the plating solution will be deepened and the viscosity will be increased, which will cause brittleness, pinholes, stripes and other phenomena of the plating solution.Therefore, we should regularly use 1~3g/L activated carbon to treat the plating solution in the production process to reduce the impact of organic impurities.
Therefore, we should pay attention to the above three points in the production process of using acid tinning brightener to avoid pinholes and streaks in the workpiece coating and reduce the occurrence of faults.If you are interested in acid tinning brightener, please contact Bigolly customer service for free samples and detailed technical information!
If you want to know more about tin plating,you can check "Electroplating encyclopedia".