Best coating for high voltage PCB
For high-voltage applications, the key requirement is high dielectric strength (insulation capability), along with resistance to moisture, contamination, and electrical arcing. The best Conforme coating is not just one type—it depends on performance level—but generally:
👉 Silicone and parylene coatings are considered the best for high-voltage PCBs

Best overall: Silicone conformal coating
Silicone Conforme coating is widely regarded as the best balance for high-voltage PCB-assemblage en SMT-assemblage.
Why silicone is ideal:
- Hoge diëlektrische sterkte (up to ~500 V/mil)
- Excellent performance under high temperature and humidity
- Flexible → reduces cracking under electrical stress
- Strong resistance to corona discharge and arcing
Silicone coatings are commonly used in power electronics, automotive systems, and industrial high-voltage designs where reliability is critical.
Best for extreme performance: Parylene coating
If you need the highest insulation performance, parylene is often the top choice in advanced Turnkey PCB-assemblage.
Advantages:
- Extremely uniform, pinhole-free coating (vapor deposition)
- Very high dielectric strength and insulation reliability
- Excellent protection against moisture and contamination
- Ideal for compact, high-voltage, high-density designs
Limitation: High cost and complex processing
Other viable options
- Polyurethaan coating
- Good dielectric strength (~350 V/mil)
- Strong chemical resistance
- Suitable for industrial environments
- Epoxy coating
- High insulation and durability
- Better for harsh environments but less flexible
- Acrylic coating
- Lower cost, moderate dielectric strength (~300–400 V/mil)
- Not ideal for high-voltage or harsh conditions
Why coating matters for high voltage
In high-voltage PCB-assemblage, risks include:
- Electrical arcing
- Leakage currents
- Electrochemical migration
- Reduced creepage distance
Conforme coating helps by:
- Increasing surface dielectric strength
- Preventing moisture-induced leakage
- Suppressing arcing and corona discharge
- Improving long-term insulation stability
Conclusie
- Best overall for high voltage: Silicone conforme coating
- Best for extreme/high-end applications: Parylene coating
- Budget alternative: Polyurethaan
In PCB-assemblage, SMT-assemblage, en Turnkey PCB-assemblage, the right coating choice should be based on voltage level, environment, and reliability requirements—not just cost.
Vraag een offerte aan voor conforme coating
Heeft u een PCB-project dat conformal coating vereist? Vraag vandaag nog een offerte op maat aan.
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