Common issues in PCB surface treatment can arise from various factors during the manufacturing process. Some of the common problems include:
- Uneven Coating:
- Issue: The surface treatment, such as the application of a conformal coating or conversion coating, may be uneven.
- Causes: Inadequate application methods, uneven substrate surfaces, or problems in the coating material.
- Poor Adhesion:
- Issue: Coatings may not adhere properly to the PCB surface.
- Causes: Contaminants on the surface, inadequate surface preparation, or mismatch between coating material and PCB substrate.
- Blistering or Bubbling:
- Issue: Formation of bubbles or blisters on the coated surface.
- Causes: Entrapped air or moisture during the coating process, incompatible coating materials, or inadequate drying/curing.
- Corrosion:
- Issue: Presence of corrosion on the PCB surface.
- Causes: Incomplete removal of oxidation or contaminants before surface treatment, use of corrosive chemicals, or exposure to harsh environmental conditions.
- Delamination:
- Issue: Separation of layers in the coating or plating.
- Causes: Inadequate adhesion, poor surface preparation, or the use of incompatible materials.
- Surface Roughness:
- Issue: The treated surface may become rough.
- Causes: Incorrect application methods, improper selection of coating materials, or issues in the preparation process.
- Electrochemical Migration:
- Issue: Unwanted metal migration between conductive traces.
- Causes: Residues from surface treatment processes, inadequate cleaning, or the presence of conductive particles.
- White Residue Formation:
- Issue: Formation of a white powdery residue on the surface.
- Causes: Incomplete rinsing after surface treatment, improper drying, or the use of incompatible chemicals.
- Peeling or Chipping:
- Issue: Coatings may peel off or chip away.
- Causes: Poor adhesion, mechanical stress, or inadequate curing/drying.
- Solderability Issues:
- Issue: Poor solderability on treated surfaces.
- Causes: Contamination, oxidation, or incompatible surface treatment materials affecting soldering performance.
To mitigate these issues, it is crucial to follow proper surface treatment procedures, use high-quality materials, and adhere to recommended environmental and process conditions. Regular quality checks and adherence to industry standards can help identify and address these problems during the manufacturing process.