This article outlines potential issues and troubleshooting methods related to the PCB nickel plating process.
1. **Porkmark:**
Porkmark, often stemming from organic pollution, manifests as large marks, typically indicative of oil contamination. Inadequate stirring can trap air bubbles, leading to porkmark formation. Addressing this, wetting agents can mitigate its impact. Smaller porkmarks, termed as pinholes, result from poor pre-treatment, metal quality, insufficient boric acid content, or low bath temperature. Rigorous plating bath maintenance and process control are crucial, with anti-pinhole agents serving as stabilizers.
2. **Roughness and Burrs:**
Dirty solutions result in roughness, remediable through thorough filtration. Extremely high pH levels can precipitate hydroxides, demanding control. Excessive current density, anode mud, or impurities from supplementary water introduce impurities, culminating in roughness and burrs.
3. **Low Adhesion:**
Incomplete deoxidation of the copper coating leads to poor adhesion, causing peeling. Interruptions in current flow or low temperatures exacerbate this issue.
4. **Brittle Coating and Poor Weldability:**
Brittleness, exposed during bending or wear, suggests organic or heavy metal pollution. Overuse of additives, entrained organics, or electroplating resists are common sources, necessitating treatment with activated carbon. Inadequate additives or high pH levels also impact coating brittleness.
5. **Dark Plating and Uneven Color:**
Metal contamination results in dark plating and uneven color. Copper plating precedes nickel plating, with copper solution being a primary pollution source. Minimizing copper solution on hangers is crucial. Corrugated steel cathodes aid in metal contamination removal. Factors like poor pretreatment, low plating, small current density, low main salt concentration, or poor electroplating power circuit contact also affect plating color.
6. **Coating Burns:**
Potential causes of coating burns include insufficient boric acid, low metal salt concentration, low temperature, high current density, high pH, or inadequate stirring.
7. **Low Deposition Rate:**
Low pH or current density results in a reduced deposition rate.
8. **Blistering or Peeling of the Coating:**
Issues such as inadequate pre-plating treatment, prolonged intermediate power-off time, organic impurity pollution, excessive current density, low temperature, high or low pH, and severe impurity influence lead to blistering or peeling.
9. **Anode Passivation:**
Insufficient anode activator, small anode area, or excessive current density lead to anode passivation.
1. **Porkmark:**
Porkmark, often stemming from organic pollution, manifests as large marks, typically indicative of oil contamination. Inadequate stirring can trap air bubbles, leading to porkmark formation. Addressing this, wetting agents can mitigate its impact. Smaller porkmarks, termed as pinholes, result from poor pre-treatment, metal quality, insufficient boric acid content, or low bath temperature. Rigorous plating bath maintenance and process control are crucial, with anti-pinhole agents serving as stabilizers.
2. **Roughness and Burrs:**
Dirty solutions result in roughness, remediable through thorough filtration. Extremely high pH levels can precipitate hydroxides, demanding control. Excessive current density, anode mud, or impurities from supplementary water introduce impurities, culminating in roughness and burrs.
3. **Low Adhesion:**
Incomplete deoxidation of the copper coating leads to poor adhesion, causing peeling. Interruptions in current flow or low temperatures exacerbate this issue.
4. **Brittle Coating and Poor Weldability:**
Brittleness, exposed during bending or wear, suggests organic or heavy metal pollution. Overuse of additives, entrained organics, or electroplating resists are common sources, necessitating treatment with activated carbon. Inadequate additives or high pH levels also impact coating brittleness.
5. **Dark Plating and Uneven Color:**
Metal contamination results in dark plating and uneven color. Copper plating precedes nickel plating, with copper solution being a primary pollution source. Minimizing copper solution on hangers is crucial. Corrugated steel cathodes aid in metal contamination removal. Factors like poor pretreatment, low plating, small current density, low main salt concentration, or poor electroplating power circuit contact also affect plating color.
6. **Coating Burns:**
Potential causes of coating burns include insufficient boric acid, low metal salt concentration, low temperature, high current density, high pH, or inadequate stirring.
7. **Low Deposition Rate:**
Low pH or current density results in a reduced deposition rate.
8. **Blistering or Peeling of the Coating:**
Issues such as inadequate pre-plating treatment, prolonged intermediate power-off time, organic impurity pollution, excessive current density, low temperature, high or low pH, and severe impurity influence lead to blistering or peeling.
9. **Anode Passivation:**
Insufficient anode activator, small anode area, or excessive current density lead to anode passivation.
