Switzerland acdc power module potting requirements(2)

Epoxies cannot be used for stress-sensitive and module sealing due to their hardness and are basically eliminated by module power supplies. However, due to its low cost, this epoxy is still used in cost-sensitive micropower supplies. Some domestic bad 48V input power supply manufacturers also use this epoxy resin acdc 48V input power supply module. However, due to stress problems, the failure rate of this 48V input power supply is very high, and buyers are miserable.

Diode loss
Diode rectification is used in traditional rectification, and Schottky diode rectification is generally used under low voltage output conditions. Compared with other rectifier diodes, Schottky diodes have the advantages of faster switching speed and lower forward voltage, but Schottky diodes The forward voltage drop of the diode is related to the size of the rectified output current. The larger the rectified output current is, the greater the forward voltage drop, which may be as high as 0.5~0.6V or more, and the reverse leakage current of the Schottky diode is larger. .

At present, the most commonly used power module is the addition of silicone. This kind of silica gel is generally 1:1, which is easy to operate. When acdc potting power modules, attention should be paid to its thermal conductivity. However, the bonding ability is not very strong, and it can be improved with 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.