Materials FAQs
This section covers conformal coating chemistries, health & safety, UV-cure, fluoropolymer nano coatings, plus Parylene dimers and adhesion promoters.
Conformal coating material FAQs
What types of conformal coating materials are available?
Acrylics, urethanes, silicones, epoxies, and Parylene. Each has unique strengths depending on environment, reliability, and rework needs.
Which conformal coating is easiest to rework?
Acrylics are the easiest to remove with solvents. Urethanes and epoxies are tougher; Parylene typically needs plasma or micro-abrasion.
Which coating is best for high-temperature environments?
Silicones maintain flexibility and stability at elevated temperatures (often >200°C), making them the usual choice.
Which coating provides the best chemical resistance?
Urethanes and epoxies offer strong resistance to fuels, solvents, and chemicals; common in aerospace and automotive.
Why choose Parylene over liquid coatings?
Parylene is vacuum-deposited as a pinhole-free film with excellent edge coverage and barrier protection for high-reliability applications.
Conformal coating health & safety FAQs
What are the main risks of solvent-based coatings?
VOC emissions require good ventilation, fume extraction, and appropriate PPE per the SDS.
Are water-based coatings safer to use?
They have very low VOCs, but still need proper handling and controlled drying to avoid defects.
What PPE should be used when handling coatings?
Gloves, safety glasses, protective clothing, and respirators where solvent levels warrant. Follow the SDS.
What workplace controls are recommended?
Local exhaust ventilation, explosion-proof extraction where required, and solvent monitoring per local regulations.
Are UV-cure coatings safer than others?
They’re low-VOC, but UV exposure needs shielding and operator eye/skin protection.
UV cure conformal coatings FAQs
What are UV-cure conformal coatings?
Materials that cure in seconds under UV light, enabling very high throughput.
Do UV-cure coatings cure under components?
Shadowed areas require a secondary cure mechanism (e.g., moisture or heat) to reach full cure.
What equipment is needed for UV curing?
UV lamps or LED systems matched in wavelength/irradiance to the coating chemistry; verify dose with radiometry.
Are UV-cure coatings reworkable?
Harder to remove than acrylics, but can be stripped with appropriate solvents or controlled abrasion.
Where are UV-cure coatings most used?
High-volume lines (automotive, consumer electronics) where cycle time is critical.
Fluoropolymer nano coating FAQs
What is a fluoropolymer nano coating?
An ultra-thin (<1 µm) hydrophobic film that repels water and contaminants without changing board appearance.
How is nano coating applied?
Typically dip or spray; often with minimal or no masking required.
What applications suit nano coatings?
Low-power electronics, sensors, and splash-resistant devices where full insulation is not required.
Does nano coating provide electrical insulation?
No—its function is water repellency and corrosion mitigation, not dielectric insulation.
Benefits over standard coatings?
Fast processing, minimal masking, invisible finish, and maintained aesthetics.
Parylene dimer FAQs
What are Parylene dimers?
Crystalline precursors vaporised, cracked, and polymerised during deposition to form the Parylene film.
How pure should dimers be?
Very high purity—impurities can cause defects, reduced adhesion, or reliability issues.
How should dimers be stored?
Sealed, clean, dry, and away from heat; prevent contamination to maintain coating quality.
Are there different dimer grades?
Yes—N, C, F, AF-4, etc., each with distinct dielectric, moisture barrier, and thermal properties.
Where are dimers sourced?
From specialist manufacturers; consistent supply chain and certification are key for regulated sectors.
Adhesion promoter FAQs
What are adhesion promoters?
Chemicals (e.g., A-174 silane) applied to improve bonding between the substrate and coating.
When should I use an adhesion promoter?
On low-energy surfaces (gold, glass, certain plastics) or in harsh/high-reliability applications to prevent delamination.
How are adhesion promoters applied?
Dip, spray, or brush prior to coating; follow supplier dwell/dry recommendations for best results.
Do all coatings need adhesion promoters?
No—use when adhesion is challenging or long-term reliability demands it; verify with adhesion testing.
Which coatings benefit most?
Parylene frequently benefits; liquid coatings may also require promoters depending on substrate and environment.
