What is the purpose of potting some switching power supplies with epoxy resin?

① Waterproof and Moisture-proof
The potting compound (mostly silicone or epoxy) completely encapsulates the circuit, forming a dense barrier that blocks water, salt spray, acids, alkalis, and other corrosive media, allowing the power supply to operate reliably in outdoor, salt spray, and high-humidity environments.

② Thermal Conductivity and Heat Dissipation
The thermal conductivity of the potting compound is 0.8-3.0 W/m·K, far higher than air. It quickly conducts heat from heat-generating components such as MOS transistors and transformers to the outer casing, effectively dissipating heat from each component and reducing temperature rise, thus extending lifespan.

③ Mechanical Fixing and Vibration Resistance
After curing, the potting compound becomes an elastomer, which can buffer vibrations and shocks, preventing solder joints and components from breaking due to mechanical stress, and improving vibration resistance.

④ Electrical Insulation and Explosion Protection
The potting compound has high dielectric strength, preventing electrical sparks from igniting internal gases; it also insulates and isolates adjacent conductors, reducing creepage distance requirements.

⑤ Process and Lifespan
No additional heat sinks are required after potting, simplifying the design; and the potting compound maintains its elasticity from -40℃ to +150℃.