Heat dissipation design of DC-DC module power supply
time：2021-01-25 17:41 author：Heat sink design click：
Approximately 15% of the damage of industrial-grade power modules is caused by poor heat dissipation. The power module is developing towards miniaturization and integration. However, in many applications, the power supply is continuously working in a closed environment. If the accumulated heat cannot be dissipated, the internal components of the power supply may be damaged due to excessive thermal stress. The usual heat dissipation methods include natural air cooling, heat sink heat dissipation, and forced heat dissipation fans.
(1) Convection ventilation of the heat sink of the power module
For power modules that rely on natural convection and thermal radiation to dissipate heat, the surrounding environment must be convenient for convection and ventilation, and there must be no large devices around it to facilitate air circulation.
(2) Placement of heating components
If there are multiple heat sources in the system, such as multiple power modules, they should be kept away from each other as much as possible to avoid the heat radiation transfer between each other and cause the power modules to overheat.
(3) Reasonable PCB board design
The PCB board provides a way to dissipate heat, which should be considered when designing. For example, increase the copper area of the main circuit, reduce the density of components on the PCB, and improve the heat dissipation area and heat dissipation channels of the module. For example, the power module should be placed as vertically as possible as shown in Figure 4, so that the heat can be dissipated upward as soon as possible;
If the DC-DC module is placed on the bottom of the PCB, the heat radiated upwards will be blocked by the PCB, resulting in the accumulated heat of the product cannot be dissipated.
(4) Larger package size and heat dissipation area
For the power supply of the same power, if possible, choose a larger package and a heat sink with a larger heat dissipation surface, or use a thermally conductive glue to connect the power module housing to the chassis. In this way, the power module has a larger heat dissipation area, the heat dissipation will be faster, the internal temperature will be lower, and the reliability of the power supply will naturally be higher.