Problems and Solutions of PCB Nickel Plating
1. Coating Burn
Possible reasons for coating burns include insufficient boric acid, low metal salt concentration, too low operating temperature, too high current density, too high pH value, or insufficient stirring.
2. Low Deposition Rate
Low pH or low current density can cause a low deposition rate.
If the copper plating layer is not activated to remove the oxide layer, the adhesion between copper and nickel will be poor, leading to peeling off of the plating layer. Interruption of the current may also cause the nickel coating to peel off. Additionally, low temperature can result in peeling.
3. Brittle Coating and Poor Solderability
When the coating is bent or worn, brittleness and poor solderability are typically revealed, indicating the presence of organic or heavy metal contamination. Excessive additives can increase the organic matter and decomposition products in the coating, which can be treated with activated carbon. Heavy metal impurities can be removed through electrolysis and other methods.
4. Darkening of the Coating and Uneven Color
Dark and uneven color of the coating indicates metal contamination, mainly from the copper solution used before nickel plating. It is crucial to minimize the copper solution on the hanger. Corrugated steel plates can be used as cathodes to remove metal pollution in the tank through electrolytic treatment. Various factors such as poor pretreatment, insufficient bottom coating, low current density, low main salt concentration, and poor conductive contact can affect the coating color.
5. Blistering or Peeling of the Coating
Factors such as poor pre-plating treatment, long intermediate power-off time, organic impurities pollution, excessive current density, low temperature, high or low pH value, and impurities can lead to blistering or peeling of the coating.
6. Anode Passivation
Insufficient anode activator, small anode area, and high current density can lead to anode passivation.
7. Pinhole
Pinholes result from organic pollution, with large pits indicating oil pollution. Poor stirring can trap air bubbles and form pits. The use of wetting agents can help reduce their impact. Pinholes can also be caused by poor pretreatment, metal impurities, low boric acid content, and low bath temperature.
8. Roughness (burr)
Roughness indicates dirty solution and can be corrected through adequate filtration. High pH can lead to hydroxide precipitation and should be monitored. High current density, impure anode mud, and contaminated water can result in roughness.
1. Coating Burn
Possible reasons for coating burns include insufficient boric acid, low metal salt concentration, too low operating temperature, too high current density, too high pH value, or insufficient stirring.
2. Low Deposition Rate
Low pH or low current density can cause a low deposition rate.
If the copper plating layer is not activated to remove the oxide layer, the adhesion between copper and nickel will be poor, leading to peeling off of the plating layer. Interruption of the current may also cause the nickel coating to peel off. Additionally, low temperature can result in peeling.
3. Brittle Coating and Poor Solderability
When the coating is bent or worn, brittleness and poor solderability are typically revealed, indicating the presence of organic or heavy metal contamination. Excessive additives can increase the organic matter and decomposition products in the coating, which can be treated with activated carbon. Heavy metal impurities can be removed through electrolysis and other methods.
4. Darkening of the Coating and Uneven Color
Dark and uneven color of the coating indicates metal contamination, mainly from the copper solution used before nickel plating. It is crucial to minimize the copper solution on the hanger. Corrugated steel plates can be used as cathodes to remove metal pollution in the tank through electrolytic treatment. Various factors such as poor pretreatment, insufficient bottom coating, low current density, low main salt concentration, and poor conductive contact can affect the coating color.
5. Blistering or Peeling of the Coating
Factors such as poor pre-plating treatment, long intermediate power-off time, organic impurities pollution, excessive current density, low temperature, high or low pH value, and impurities can lead to blistering or peeling of the coating.
6. Anode Passivation
Insufficient anode activator, small anode area, and high current density can lead to anode passivation.
7. Pinhole
Pinholes result from organic pollution, with large pits indicating oil pollution. Poor stirring can trap air bubbles and form pits. The use of wetting agents can help reduce their impact. Pinholes can also be caused by poor pretreatment, metal impurities, low boric acid content, and low bath temperature.
8. Roughness (burr)
Roughness indicates dirty solution and can be corrected through adequate filtration. High pH can lead to hydroxide precipitation and should be monitored. High current density, impure anode mud, and contaminated water can result in roughness.
