The temperature of sealing solution is too high: when the temperature of sealing solution exceeds a certain value, such as more than 35°C, a thin "powder frost" may appear, and if the temperature continues to rise to more than 40°C, an obvious "powder frost" will appear. High-temperature sealing is usually combined with the use of sealing and dust suppression agents to control the production of se
What causes grey after anodizing sealing?
Author: Robby
The main reasons for greying after anodising closure include the following:
The temperature of sealing solution is too high: when the temperature of sealing solution exceeds a certain value, such as more than 35°C, a thin "powder frost" may appear, and if the temperature continues to rise to more than 40°C, an obvious "powder frost" will appear. High-temperature sealing is usually combined with the use of sealing and dust suppression agents to control the production of sealing ash.
Sealing time is too long: sealing time more than 20min, especially more than 30min, easy to appear obvious "frost". Long parts in the sealing solution if the two ends of the method, the middle section due to double the two ends of the sealing time, reflecting particularly obvious, so this sealing method should not be promoted.
Sealing solution in F-concentration is too high: sealing solution in F-concentration is too high, the phenomenon of "frost" is very obvious. It is necessary to detect and adjust the F-concentration in the sealing solution.
Pre-treatment grey is not clean: If the pre-treatment step does not clean the workpiece thoroughly, the dust carried will be adsorbed in the hole sealing process, resulting in grey on the surface of the workpiece.
Sealing White Mist: In the case of a poor sealer, a white, misty grey may appear on the surface of the workpiece, which is usually caused by the acidic pH of the sealing tank fluid and the associated rinsing tank.
Sealing grey: Dirt adsorbed on the surface of the workpiece after complete blocking of the microvia may also be the cause of sealing grey. This can be caused by impurities in the sealer composition or tank solution of the over-sealed holes.
Aging or contamination of the sealing solution: Aging or contamination of the sealing solution can also lead to grey on the surface of the workpiece after sealing.
Solutions to these problems include adjusting the temperature and time of the sealing solution, controlling the F-concentration, ensuring that the pre-treatment step thoroughly cleans the workpiece, checking and adjusting the pH of the sealing tank solution, and replacing or disposing of the sealing solution on a regular basis.