Why are switching power supplies encapsulated with potting compound?

In industrial power supplies, LED drivers, communication base stations, and other outdoor equipment, we often see switching power supplies that are completely "potted"—the entire circuit board is completely encased in a layer of transparent or gray resin. This seemingly ordinary resin is actually the "invisible armor" of the switching power supply, providing five core functions to ensure its long-term stable operation in harsh environments.

I. Waterproof and Moisture-proof – "Invisible Waterproof Casing"
The primary function of potting is waterproofing and moisture protection. The potting compound (mostly silicone or epoxy resin) forms a dense, non-porous barrier after curing, effectively blocking water, salt spray, acids, alkalis, and other corrosive media. This allows the power supply to operate reliably in high-humidity, outdoor, and salt-spray environments (IP65/IP67), eliminating the need for an additional waterproof casing and significantly reducing overall cost and size.

II. Thermal Conductivity and Heat Dissipation – "Thermal Conductive Heat Sink"
The thermal conductivity of the potting compound (0.8-3.0 W/m·K) is significantly higher than that of air, allowing it to quickly transfer heat from heat-generating components such as MOS transistors and transformers to the casing or heat sink, reducing temperature rise and extending the power supply's lifespan. Experiments show that potting can reduce the internal temperature rise of the power supply by 10-20℃, equivalent to extending the power supply's lifespan by more than 30%.

III. Vibration and Shock Resistance – "Elastic Shock Absorbing Pad"
After curing, the potting compound forms an elastomer that effectively absorbs and dampens vibrations, shocks, and drops, preventing solder joints and components from breaking due to mechanical stress. This allows the power supply to operate reliably in harsh mechanical environments with vibration and drops, without the need for additional shock-absorbing structures.

IV. Electrical Insulation and Explosion Protection – "Insulating and Explosion-proof Layer"
The potting compound has high electrical insulation strength, effectively isolating adjacent conductors, reducing creepage distance requirements, and preventing electrical sparks from igniting internal gases. The resin also isolates adjacent conductors, reducing creepage distance requirements and preventing electrical sparks from igniting internal gases, improving the power supply's explosion-proof rating.

V. Process and Lifespan – "Simplified Casing + Long Lifespan"
Potting eliminates the need for additional heat sinks and shock-absorbing structures, simplifying the overall design and reducing manufacturing costs. Meanwhile, the potting compound maintains its elasticity from -40℃ to +150℃, allowing the power supply to operate stably for extended periods in harsh environments such as extreme cold and high temperatures, without the need for additional temperature control structures.

VI. Industry Applications
Potted power supplies are widely used in:
LED lighting: Wall washers, floodlights, stage lights, and other outdoor lighting;
Industrial control: PLCs, servos, motors, and other industrial equipment;
Communication base stations: 5G base stations, communication equipment, and other outdoor equipment;

VII. Direct Supply from Manufacturers
Hengjunfeng Technology: Full range of 24V-72V products, IP67 aluminum casing potting, CCC/CE certified, 5-7 day delivery;
Chengdian Xinsheng Technology: Ultra-thin aluminum casing + APP voltage regulation, OEM/ODM with no minimum order quantity.