ACDC power module potting requirements

The encapsulation of ACDC power module is very important. This process not only involves the encapsulation of power module and the protection of ACDC power module (waterproof, moisture-proof, dust-proof, anti-corrosion, etc.), but also involves the protection of power module and the thermal design of ACDC power module.

ACDC power module

The commonly used potting materials for power modules are divided into epoxy resin, polyurethane and silicone rubber

Due to hardness, epoxy resin can not be used for stress sensitive and module sealing, and is basically eliminated by module power supply. However, due to the low cost, this epoxy resin is still used in the micro power supply with high cost requirements. Some domestic bad power supply manufacturers also use this epoxy ACDC power supply module. However, due to the stress problem, the failure rate of this power supply is very high, and the buyer is miserable.

At present, the most commonly used power module is additive silicone. The silica gel is generally 1:1, which is easy to operate. Attention should be paid to the thermal conductivity of ACDC power module when it is potted. However, the adhesive ability is not very strong and can be improved by primer.

Polyurethane has been used in China for a period of time, but due to its high hardness, inconvenient maintenance, and the price reduction of silicone rubber, the cost performance of polyurethane is not high. It has basically no application in China.

Special attention should be paid to the thermal conductivity related to thermal design. Generally, a thermal conductivity of 0.4w/m · K is defined as high thermal conductivity, and a thermal conductivity greater than 1 is defined as extremely high thermal conductivity