Thermal Interface Grease for Drone Motor and ESC
A silicone-based thermal interface material (TIM) compound filled with aluminum oxide (Al₂O₃) and zinc oxide (ZnO) particles, delivering thermal conductivity of 3–6 W/m·K for heat transfer between drone brushless motor stator windings and motor can, between ESC FET switches and heat spreader, and between power electronics and carbon fiber or aluminum heat-dissipating structures.
Key Features
- ✓Thermal conductivity 3–6 W/m·K — lowers motor winding temperature 15–25°C vs no TIM, extending insulation life exponentially
- ✓Thermal resistance <0.05 cm²·K/W at 50 μm — 10–30× lower than ungreased drone motor metal-to-metal contacts
- ✓Volume resistivity >10¹² Ω·cm — electrically non-conductive, safe between motor windings and can
- ✓Operating range -55°C to +200°C — stable from Arctic drone operations to continuous full-power motor temperatures
- ✓Non-curing silicone base — reworkable for motor maintenance, ESC swaps, and field servicing
- ✓Oil separation <1 wt% at 200°C/200h — grease remains in place throughout motor operational life
Specifications
| Parameter | Value |
|---|---|
| Color | White to light grey |
| Filler | Al₂O₃ + ZnO (mixed oxide, non-reactive) |
| Cure type | Non-curing (reworkable) |
| Base fluid | Polydimethylsiloxane (PDMS) |
| Volume resistivity | >10¹² Ω·cm |
| Thermal conductivity | 3–6 W/m·K (ASTM E1461) |
| Operating temperature range | -55°C to +200°C |
| Viscosity (shear rate 10/s) | 150,000–300,000 mPa·s |
| Oil separation (200h, 200°C) | <1 wt% |
| Thermal resistance (50 μm BLT) | <0.05 cm²·K/W |
FAQ
The optimal bond line thickness (BLT) for thermal grease is 25–100 μm — just enough to fill surface asperities. Applying too much grease (BLT >500 μm) increases thermal resistance because you are adding a thick insulating layer of filler-in-silicone rather than a thin interface layer. For drone motors, apply a very thin bead (0.3–0.5 g for a typical 2206–2306 motor stator) in a spiral pattern over the stator OD, then press the motor can on axially. The grease will spread to a uniform thin layer under assembly pressure. Wipe excess from the motor shaft and bearing area — thermal grease on bearings increases drag.