What is the burr phenomenon in the high current area when the workpiece is plated with acidic copper brightener?

We have used Biglet's acid copper brightener for a long time, and there is no burr in the high current area. However, when this happens in the production process, the following five points should be noted:

1. The chloride content in electroplating solution is too high.

2. The iron impurity content in the electroplating solution is too high or the electroplating solution contains antimony and arsenic impurities.

3. Improper use of brightener or unbalanced brightener.

4. Use inferior cast copper anode.

5. Improper hanging mode of the workpiece, insufficient air stirring of the plating solution or poor cleaning.