We all know that the heat generated by the operation of electronic equipment can cause the temperature inside the equipment to rise rapidly. If the heat is not dissipated in time, the device will continue to heat up, the device will fail due to overheating, and the reliability of the electronic device will decrease. Therefore, the heat sink is very important. The direct factor of the temperature rise of the circuit board is the existence of power-consuming components, and the heating intensity changes with the power consumption. There are two phenomena of temperature rise: local temperature rise or whole area temperature rise, short-term temperature rise or long-term temperature rise. The specific reasons are generally analyzed from the following aspects:

Power consumption: analysis of power consumption per unit area, analysis of power consumption distribution on the PCB.

The structure of the circuit board PCB: size, material.

How to install the circuit board: installation method (such as vertical installation, horizontal installation), sealing condition and distance from the casing.

Thermal radiation: the emissivity of the surface of the PCB board, the temperature difference between the circuit board and the adjacent surface, and its absolute temperature;

Heat conduction: installation of heat sinks, conduction of other installation structural components of circuit boards and PCBs.

Thermal convection: natural convection, forced cooling convection.