In the production process of using sulfate tin plating additives, sometimes the corners of the workpiece appear scorched. What is the reason?
According to the field experience and the characteristics of the product sulfate tin plating additives Sn-807, there are four main reasons:
1. The cathode current density is too large.The cathode current density is high, the coating layer is loose, rough and porous, the corners are easy to scorch, and it is easy to appear brittle.The current density should be reduced to within the process range.
2. The concentration of divalent tin is too low.If the concentration of divalent tin is too low, the low current density of the cathode will be low, the production efficiency will also be reduced, and the coating will be easily scorched.The concentration of the components of the plating solution should be analyzed and adjusted to the process range in time.
3. The cathode moving speed of the plating solution is not enough.The sulfate tin plating process cannot be stirred with air, and the bright plating layer must be obtained by moving the cathode, which can improve the production efficiency.If the moving speed of the cathode is not enough, the coating will be rough and easy to burn, so the moving speed should be adjusted.
4. The softener in the plating solution is insufficient.The softener can improve the dispersion ability of the plating solution, improve the cathodic polarization, refine the crystallization of the plating layer, and reduce the pores.When the softener in the plating solution is insufficient, the dispersing ability of the coating decreases, the crystals are relatively rough, and it is easy to burn.An appropriate amount of softener should be added to the normal range.
Therefore, we should pay attention to the above four points in the production process of using sulfate tin plating additives, which can avoid the phenomenon of burning the corners of the workpiece, reduce the occurrence of failures, and effectively improve production efficiency.