Netherlands acdc power module potting requirements(2)
high frequency switch
The rapid development of the communication industry has greatly promoted the development of communication power. High frequency miniaturized switching power supply and its technology have become the mainstream of modern communication power supply system. In the field of communication, the rectifier is usually called the primary power supply, and the direct current-direct current (DC/DC) converter is called the secondary power supply. The role of the primary power supply is to convert the single-phase or three-phase AC power grid into a DC power supply with a nominal value of 48V. In the primary power supply for program-controlled switches, the traditional phase-controlled regulated power supply has been replaced by a high-frequency switching power supply. Controlled in the 50-100kHz range for high efficiency and miniaturization. In recent years, the power capacity of switching rectifiers has been continuously expanded, and the single-unit capacity has been expanded from 48V/12.5A, 48V/20A to 48V/200A, 48V/400A.
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 24V input power supply manufacturers also use this epoxy resin acdc 24V input power supply module. However, due to stress problems, the failure rate of this 24V input power supply is very high, and buyers are miserable.
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.