Surface Preparation & Cleanliness for Reliable Coating

Effective surface preparation and cleanliness are critical for conformal coating reliability. Contaminants such as flux residues, oils, and ionic salts can cause adhesion loss, corrosion, or electrical leakage. This guide covers cleaning methods, cleanliness testing, adhesion promoters, and industry standards.

Illustration of PCB surface preparation showing cleaning spray, plasma treatment glow, and adhesion promoter bottle for reliable conformal coating

Why Surface Preparation Matters

  • Adhesion: A clean, dry surface ensures coating bonds strongly to substrates.
  • Electrical reliability: Ionic contamination can lead to dendritic growth, leakage currents, or corrosion.
  • Consistency: Proper preparation reduces defects like dewetting, bubbles, and delamination.

Surface Preparation Methods

  • Cleaning: Aqueous, semi-aqueous, and solvent systems remove flux and oils.
  • Plasma treatment: Improves surface energy, ideal for Parylene adhesion.
  • Micro-abrasion: Removes oxides, residues, or old coatings in rework.
  • Adhesion promoters: Silanes such as A-174 or specialty primers increase bonding.

Cleanliness Testing

  • ROSE / Ionic Contamination Test: Measures ionic residues in μg NaCl/cm².
  • Ion Chromatography: Identifies specific contaminants (chlorides, weak organic acids).
  • Dyne Pen / Contact Angle: Evaluates surface energy for coating wetting.

Standards & Guidance

  • IPC-5704 – Cleanliness requirements for printed boards
  • IPC-A-610 – Acceptability of electronic assemblies (cleanliness & coating coverage)
  • IEC 60664 – Insulation coordination & pollution degree context
  • Customer specifications may define tighter ionic or adhesion requirements

SCH Surface Preparation Solutions

We provide surface preparation tools, training, and consultancy:

Need support with conformal coating surface preparation?
SCH provides cleaning systems, adhesion promoters, and training for reliable coating performance.

Why Choose SCH Services?

Partnering with SCH Services means more than just outsourcing — you gain a complete, integrated platform for
Conformal Coating, Parylene & ProShieldESD Solutions, alongside equipment, materials, and training, all backed by decades of hands-on expertise.

  • ✈️ 25+ Years of Expertise – Specialists in coating technologies trusted by aerospace, medical, defence, automotive, and electronics industries worldwide.
  • 🛠️ End-to-End Support – Guidance on coating selection, Parylene grades, masking strategies, application methods, inspection, and ProShieldESD integration.
  • 📈 Scalable Solutions – From small prototype batches to full-scale, high-volume production, SCH delivers flexible capacity that grows with your needs.
  • 🌍 Global Reach – Responsive technical support and supply coverage across Europe, North America, and Asia.
  • ✅ Proven Reliability – A strong reputation built on quality, consistency, and customer satisfaction across services, equipment, and materials.

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✉ Email: sales@schservices.com
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