It's So Hot. How To Cool PCB

Today, many places in guangdong have issued a high temperature yellow warning signal, at noon in guangdong, a red daze. In the coming days, guangdong residents will continue to receive "care" from rain and the sun, and will be in a "continuous steaming and baking" mode, according to the observatory.

Since the weather is so hot, today we will talk about PCB cooling design.


For electronic equipment, a certain amount of heat will be generated during work, which will rapidly increase the internal temperature of the equipment. If the heat is not emitted 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 do a good cooling treatment for the circuit board.


PCB design is a downstream process closely following the principle of design, and the quality of design directly affects the product performance and marketing cycle. As we know, every device on PCB has its own operating environment temperature range. If the temperature range is exceeded, the working efficiency of the device will be greatly reduced or fail, resulting in the damage of the device. Therefore, heat dissipation is a key issue in PCB design.

Then, as a PCB design engineer, how to carry out heat dissipation treatment?


PCB heat dissipation and plate selection, components selection, components layout and other aspects are related. Among them, layout plays a decisive role in PCB heat dissipation, which is the key link of PCB heat dissipation design. Engineers should consider the following aspects when making layout:


(1) centralized design and installation of components with high heating and large radiation on another PCB board, so as to conduct separate centralized ventilation and cooling to avoid mutual interference with the motherboard;


(2) PCB board heat capacity is evenly distributed. Do not centralize large power consumption devices. If it is unavoidable, put the high components on the upstream of airflow, and ensure enough cooling air flow through the heat consumption concentration area;


(3) make the heat transfer pathway as short as possible;


(4) make the heat transfer cross section as large as possible;


(5) the influence of thermal radiation on surrounding parts should be taken into account in component layout. Heat-sensitive parts and components (including semiconductor devices) should be kept away from heat sources or isolated;


(6) pay attention that forced ventilation is in the same direction as natural ventilation;


(7) the air duct of additional subplates and devices is in the same direction as the ventilation;


(8) make enough distance between intake and exhaust as far as possible;


(9) heating devices should be placed as far as possible on top of the product, and should be in the air flow path when conditions permit;


the components with high heat or current should not be placed in the corners and edges of PCB board, and the radiator should be installed as far as possible, away from other components, and ensure the heat dissipation channel is unobstructed.


Reminder: adding a radiator to the device is also a good way to dissipate heat.