switching power supply thermal design points

    Heat dissipation is an important condition to ensure the safe and reliable operation of switching power adapter. If the temperature is too high, the performance index of the power supply will change, and even the failure of the power adapter will be caused. Therefore, the fundamental task of heat dissipation design is to control the temperature rise so that it does not exceed the specified limit of reliability.

   The components of the switching power adapter have certain requirements for the working temperature range. If the temperature exceeds its limit, it will cause the change of the working state of the power supply, so that the electronic equipment can not work stably and reliably, shorten its service life, and even cause the damage of the electronic equipment.

      Therefore, we should pay more attention to the thermal design of the power supply switch , below are some design points for reference when designing the thermal solution for the devices:

1. Selection of heatsink. The principle of heatsink selection is to select a heatsink with small volume and light weight as far as possible on the premise of ensuring sufficient heat dissipation, so as to save internal space and reduce the total weight of power adapter.

2. Installation of heatsink. When installing the heatink, the installation method with small heat dissipation and thermal resistance shall be selected as far as possible.

3. Minimize the thermal resistance of the interface. The surface of the heatsink shall be flat and smooth, applied with silicone grease or heat conducting gasket to reduce the contact thermal resistance between the radiator and the power semiconductor.

4. Heatsink surface treatment . In order to increase the radiation capacity of the heatsink, the surface of the heatsink can be coated with a layer of high radiation coefficient coating such as black paint or oxide. The radiator with black coating shall be preferred and the coating shall be protected from damage.

5. Installation position of power semiconductor. The power semiconductor shall be installed in the center of the heatsink, so that the heatsink can be heated evenly and improve the heat dissipation efficiency.

6. Position of heatsink. The heatsink shall be in direct contact with the air flow outside the power supply as far as possible to reduce the ambient temperature. At the same time, the effect of convective heat transfer of radiator can be improved.