The weather is so hot, let's talk about how to cool the PCB

The weather is so hot, let's talk about how to cool the PCB

Today, many places in Guangdong have issued high-temperature yellow warning signals. At noon, the land of Guangdong is in a trance. According to the Meteorological Observatory, in the next few days, the Cantonese will continue to accept the "care" of rain and the sun, in a "steaming and roasting" mode.

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

For electronic equipment, a certain amount of heat is generated during operation, which causes the internal temperature of the equipment to 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 Performance will decrease. Therefore, it is very important to dispose the circuit board well.

PCB design is a downstream process that closely follows the principle design. The quality of the design directly affects product performance and time to market. We know that the devices on the PCB board have their own working environment temperature range. If this range is exceeded, the working efficiency of the device will be greatly reduced or fail, resulting in damage to the device. Therefore, heat dissipation is an important issue in PCB design.

So, as a PCB design engineer, how should the heat treatment be done?

The heat dissipation of PCB is related to the choice of plate, the choice of components, and the layout of components. Among them, the layout plays an important role in PCB heat dissipation, which is the key link of PCB heat dissipation design. Engineers need to consider the following aspects when performing layout:

(1) Centrally design and install components with high heat generation and large radiation on another PCB board, so that separate centralized ventilation and cooling are performed to avoid mutual interference with the main board;

(2) The heat capacity of the PCB surface is evenly distributed. Do not distribute large-power-consumption devices. If it is unavoidable, place short components upstream of the air flow and ensure that sufficient cooling air flows through the heat-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 layout of components should take into account the influence on the heat radiation of surrounding parts. Heat sensitive parts and components (including semiconductor devices) should be kept away from heat sources or isolated;

(6) Pay attention to the direction of forced ventilation and natural ventilation;

(7) The additional daughter board and device air duct are consistent with the ventilation direction;

(8) Make the intake air and exhaust air as far as possible;

(9) The heating device should be placed above the product as much as possible, and should be in the air flow channel when conditions permit;

(10) Do not place components with large heat or current in the corners and surrounding edges of the PCB board. Install radiators as far as possible, and keep them away from other devices, and ensure that the heat dissipation channel is unobstructed.