Silicone Conformal Coating for Drone PCB
A one-component, room-temperature vulcanizing (RTV) silicone conformal coating for protecting drone flight controller, ESC, and receiver PCBs against moisture, condensation, agricultural chemical spray, salt mist, and particulate contamination.
Key Features
- ✓MIL-I-46058C (Type SR) compliance — documented qualification for military and defense UAV PCB protection
- ✓Operating range -65°C to +200°C — no delamination from high-altitude cold soak to under-hood electronics heat
- ✓Dielectric strength 18 kV/mm — prevents tracking between tight-pitch PCB traces under condensation
- ✓One-component moisture cure — no mixing, no pot life — drone PCB production line friendly
- ✓25–130 μm film thickness per pass — conformal, non-bridging over fine-pitch SMD components
- ✓Reworkable with silicone solvent — ESC FET and sensor replacement possible after coating
Specifications
| Parameter | Value |
|---|---|
| Coating type | One-component RTV silicone (moisture cure) |
| Viscosity (23°C) | 1,000–3,000 mPa·s |
| Volume resistivity | >10¹⁴ Ω·cm |
| Dielectric strength | 18 kV/mm (IEC 60243) |
| Mil-spec compliance | MIL-I-46058C, Type SR |
| Operating temperature range | -65°C to +200°C |
| Tack-free time (23°C, 50%RH) | 30 min |
| Full cure depth (23°C, 50%RH) | ≥3 mm / 24 h |
| Cured film thickness (single pass) | 25–130 μm |
| Moisture resistance (MIL-I-46058C) | Pass (168h at 65°C / 95%RH) |
FAQ
Three methods are used for drone PCB conformal coating: (1) Selective robotic dispense — a dispensing robot applies a bead of coating to specific areas under CNC control, avoiding connectors, test points, and RF shields. This is the production-scale preferred method, providing consistent coverage without operator variation. (2) Spray application — manual aerosol or spray gun application followed by masking of excluded areas. Good for prototype and small-batch production. Apply 2–3 thin passes with 10-minute flash-off between passes. (3) Brush application — for field repair and individual PCB protection. Use a flat brush and apply in long single strokes to minimize bubbles. Mask all connectors, crystal oscillators, fans, and any component that requires connectivity access. Do not coat solder pads, header pins, or trim potentiometers.