Which silicone conducts heat particularly well?
Unfilled silicone is a poor heat conductor. Thermally conductive silicones therefore contain special mineral fillers that carry heat from components such as power semiconductors, coils or LEDs to the heat sink or housing – while keeping the typical silicone benefits of electrical insulation, elasticity and temperature resistance.
What does W/mK mean?
Thermal conductivity is given in watts per metre and kelvin (W/mK). The higher the value, the better heat is dissipated. Just as important is a thin, gap-free layer: air gaps insulate strongly and quickly cancel out the benefit of a good material.
Paste or potting compound?
- Thermal paste – non-curing, for thin layers between component and heat sink. Components remain removable.
- Thermally conductive potting compound – cures, encapsulates complete assemblies, protects against moisture and vibration and spreads heat to the housing.
Suitable products
- WACKER Silicon-Paste P12 – thermally conductive silicone paste (0.6–0.8 W/mK) for electronics, e.g. between component and heat sink.
- ELASTOSIL RT 675 A/B – thermally conductive, addition-curing two-part potting compound (1:1) for power supplies, control units and motor electronics.
- For potting without special thermal requirements: ELASTOSIL RT 601 A/B or ELASTOSIL RT 607 A/B.
Practical tips
- Fillers can settle during longer storage – stir the components well before use.
- Filled compounds are usually more viscous: design the potting space so the compound flows well and air can escape.
- Apply paste as thinly and evenly as possible and press components firmly.
Questions about choosing a product? Call us on +41 61 322 42 24 (Mon–Fri 08:15–12:00 and 13:30–17:00) or write to info@ameba.ch.