The direct cause of the temperature rise of the printed board is due to the existence of circuit power consumption devices. The electronic devices have different degrees of power consumption, and the heat generation intensity varies with the power consumption.
Two phenomena of temperature rise in printed boards:
(1) Local temperature rise or large area temperature rise;
(2) Short-term temperature rise or long-term temperature rise.
When analyzing PCB thermal power consumption, it is generally analyzed from the following aspects.
1. Electrical power consumption
(1) Analysis of power consumption per unit area;
(2) Analyze the distribution of power consumption on the PCB.
2. The structure of the printed board
(1) the size of the printed board;
(2) The material of the printed board.
3. How to install the printed board
(1) Installation method (such as vertical installation, horizontal installation);
(2) Sealing condition and distance from the casing.
4. Thermal radiation
(1) the emissivity of the surface of the printed board;
(2) the temperature difference between the printed board and the adjacent surface and their absolute temperature;
5. Heat conduction
(1) installing a radiator;
(2) Conduction of other mounting structural members.
6. Hot convection
(1) Natural convection;
(2) Forced cooling convection.
The analysis of the above factors from the PCB is an effective way to solve the temperature rise of the printed board. These factors are often related and dependent in a product and system. Most of the factors should be analyzed according to the actual situation, only for a specific In actual conditions, parameters such as temperature rise and power consumption can be calculated or estimated correctly.