Exception description: black spots on the copper rough surface (black spots on the rough surface after copper foil post-processing, and more on both sides of the middle decrease).

Measures taken:

1.1 The 5-micron filter bag and coarse solidified activated carbon filter element were replaced, which was invalid.  

1.2 The production current of coarse curing (three coarse and three solid/the current decreases in sequence) is adjusted (the total current is reduced from 26000 to 25000), which is invalid.  

1.3 Section by section electroplating was carried out, and it was found that black spots were produced from the first roughening. This friend encountered the problem of black spots on the rough surface of copper foil, and tried many ways to solve it, but the problem was not solved. After contacting me, I gave some suggestions on how to solve the problem, and I will share them with you here.  

1. This problem can be determined in which process the problem occurs first. After roughening, there will be black spots, which can be preliminarily judged as the electrolytic oxidation point of electrolytic products, or it can be judged by passing through the surface treatment machine without power transmission alone to see whether there are black spots.

2. The product reason of electrolytic oxidation point is that the oxidation point will appear if the electrolytic water is not washed thoroughly.

3. The electrolytic induced draft system is poor, resulting in more acid mist in the environment. This can also explain the problem of less in the middle and more on both sides.  

Solution:

1. Increase the amount of electrolytic water washing, adjust the washing angle, and adjust the water pressure.  

2. Clean the induced air of electrolytic cell to ensure good induced air.  

3. This problem can also be alleviated by increasing the strength of surface treatment pickling and the concentration of pickling solution.