Mechanical Polishing/Finishing: Ensure the substrate is smooth before plating. Any rough edges or micro-burrs from machining will be amplified during plating. Deburring: Use mechanical (vibratory finishing, abrasive blasting) or chemical deburring to remove sharp edges. Cleaning & Degreasing: Remove oils, oxides, and contaminants using alkaline cleaning, acid pickling,
Author: Robby
Avoiding burrs on the surface of a product during electroless nickel plating (EN plating) requires careful attention to pre-treatment, plating parameters, and post-processing. Here are key steps to minimize or eliminate burrs:
Mechanical Polishing/Finishing: Ensure the substrate is smooth before plating. Any rough edges or micro-burrs from machining will be amplified during plating.
Deburring: Use mechanical (vibratory finishing, abrasive blasting) or chemical deburring to remove sharp edges.
Cleaning & Degreasing: Remove oils, oxides, and contaminants using alkaline cleaning, acid pickling, or ultrasonic cleaning to ensure uniform plating.
Temperature: Maintain optimal bath temperature (typically 85–95°C for most EN solutions). Fluctuations can cause uneven deposition.
pH Level: Keep pH stable (usually 4.5–5.0 for acidic baths, 8–10 for alkaline baths). High pH can increase roughness.
Bath Filtration: Use continuous filtration (1–5 µm) to remove particulates that can cause nodular growth.
Agitation: Gentle mechanical or air agitation prevents hydrogen bubbles from adhering to the surface, which can lead to pits or roughness.
Deposition Rate: Avoid excessively high deposition rates (typically 15–25 µm/hr is optimal). Faster plating can lead to nodule formation.
Bath Loading: Do not overload the bath; maintain proper workpiece-to-solution ratio to prevent "burning" or rough deposits.
Stabilizer Concentration: Proper stabilizer (e.g., lead, thiourea) levels prevent spontaneous decomposition, which can cause roughness.
Rinsing: Thoroughly rinse the plated part to remove residual chemicals that could cause staining or roughness.
Heat Treatment: If needed, bake at 180–200°C for 1–2 hours to relieve stress and improve adhesion (but avoid excessive heat if burrs are a concern).
Mechanical Finishing: Light polishing or buffing can remove minor surface irregularities.
Material Uniformity: Ensure the substrate has no porosity, inclusions, or inconsistent metallurgy.
Edge Design: Avoid sharp corners; chamfer or radius edges to promote uniform plating.
Regular Analysis: Monitor nickel, hypophosphite, and contaminant levels (e.g., zinc, copper, organic impurities).
Purification: Use activated carbon treatment or dummy plating to remove contaminants.
| Cause | Solution |
|---|---|
| Poor pre-cleaning | Improve degreasing & etching |
| Bath contamination | Filter & purify plating solution |
| High deposition rate | Adjust temperature/pH, reduce loading |
| Hydrogen bubbles | Increase agitation |
| Substrate defects | Improve surface finish before plating |
By following these guidelines, you can achieve a smooth, burr-free electroless nickel-plated surface. If burrs persist, consider consulting your plating solution supplier for tailored adjustments.