PCB Cleaning for Conformal Coating Preparation
Adhesion and coverage of conformal coatings depend on surface cleanliness. Oils, flux residues, and particulates reduce wetting and create voids that allow moisture ingress. Proper pre-coating cleaning is a prerequisite for long-term protection.
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surface energy must support coating wetting
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contamination leads to delamination and voiding
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test adhesion and perform water-break tests
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process control ensures consistent coating adhesion
Importance of cleanliness before coating
Coatings fail at contaminated interfaces, leading to localized corrosion and electrical failure. Water-break and contact-angle tests quickly indicate inadequate cleaning. For safety-critical products, adhesion testing is part of qualification.
Recommended cleaning procedures
Recommend multi-stage cleaning: degrease, aqueous precision clean, rinse, and controlled drying. Plasma or solvent wipe can be used for local stubborn films. ZESTRON offers chemistries and validation protocols that ensure coatings adhere and pass accelerated humidity testing.