The direct cause of PCB temperature rise is due to the existence of circuit power dissipation devices, electronic devices have different degrees of power dissipation, and the heating intensity varies with the power dissipation.

2 phenomena of temperature rise in PCB:

(1) local temperature rise or large area temperature rise;

(2) short-term or long-term temperature rise.

In the analysis of PCB thermal power, the following aspects are generally analyzed:

1. Electrical power consumption

(1) analyze the power consumption per unit area;

(2) analyze the power distribution on the PCB.

2. Structure of PCB

(1) the size of PCB;

(2) the materials.

3. Installation of PCB

(1) installation method (such as vertical installation and horizontal installation);

(2) sealing condition and distance from the housing.

4. Thermal radiation

(1) radiation coefficient of PCB surface;

(2) the temperature difference between the PCB and the adjacent surface and their absolute temperature;

5. Heat conduction

(1) install radiator;

(2) conduction of other installation structures.

6. Thermal convection

(1) natural convection;

(2) forced cooling convection.

PCB analysis of the above factors is an effective way to solve the PCB temperature rise, often in a product and system these factors are interrelated and dependent, most factors should be analyzed according to the actual situation, only for a specific actual situation can be more correctly calculated or estimated temperature rise and power parameters.