For electronic equipment, some heat will be generated during operation, so that the internal temperature of the equipment will rise rapidly. If the heat is not dissipated in time, the equipment will continue to heat up, the device will fail due to overheating, and the reliability of electronic equipment will decline. Therefore, it is very important to heat the circuit board well.
PCB design is closely following the downstream process of principle design. The quality of design directly affects product performance and marketing cycle. We know that all devices on PCB have their own working environment temperature range. If the range is exceeded, the working efficiency of devices will be greatly reduced or fail, resulting in device damage. Therefore, heat dissipation is an important problem in PCB design.
So, as a PCB Design Engineer, how to conduct heat dissipation?
The heat dissipation of PCB is related to the selection of board, components, layout of components and so on. Among them, layout plays an important role in PCB cooling, and is the key link of PCB cooling design. The engineer needs to consider the following aspects when making layout:
(1) centralized design and installation of components with high heat and large radiation on another PCB, so as to separate centralized ventilation and cooling and avoid mutual interference with the main board;
(2) the heat capacity of PCB board is evenly distributed. Do not place the high-power components in a centralized way. If it cannot be avoided, put the low components in the upstream of the air flow, and ensure enough cooling air flow through the heat consumption concentration area;
(3) make the heat transfer path as short as possible;
(4) make the heat transfer cross section as large as possible;
(5) the influence on the thermal radiation of surrounding parts shall be considered in the layout of components. Parts and components (including semiconductor devices) sensitive to heat shall be kept away from heat source or isolated;
(6) pay attention to the same direction of forced ventilation and natural ventilation;
(7) the air ducts of additional daughterboards and devices shall be consistent with the ventilation direction;
(8) make enough distance between air inlet and exhaust as far as possible;
(9) the heating device shall be placed above the product as far as possible, and it shall be placed on the air flow channel when conditions permit;
(10) components with large heat or current shall not be placed at the corner and surrounding edge of PCB, and radiators shall be installed as far as possible, away from other components, and the cooling channel shall be smooth.
Oct 10, 2019
