What are the ways to dissipate heat from the circuit board?

1.High-heat devices plus heat sinks, heat conduction plate.

When the PCB has a small number of devices with a large amount of heat (less than 3), the heat device can be added to the heat sink or heat pipe, when the temperature can not be reduced, can be used with a fan of the radiator, in order to enhance the heat dissipation effect. When the amount of heat-generating device is more (more than 3), you can use a large heat sink cover (plate), which is customized according to the location of the heat-generating device on the PCB board and the height of the special radiator or in a large flat radiator keyed to the different components of the height of the position. The heat sink cover will be fastened to the component surface as a whole, and each component contact and heat dissipation. However, due to the poor consistency of the height of the components when soldering, the heat dissipation effect is not good. Usually add a soft thermal phase change thermal pad on the component surface to improve the heat dissipation effect.

2.Adopt reasonable alignment design to realize heat dissipation.

Since the resin in the board has poor thermal conductivity and the copper foil lines and holes are good conductors of heat, improving the copper foil residual and increasing the heat-conducting holes are the main means of heat dissipation. To evaluate the heat dissipation capability of PCBs, it is necessary to calculate the equivalent thermal conductivity (nine eq) of a composite material consisting of various materials with different coefficients of thermal conductivity, i.e., an insulating substrate for PCBs.

3. For the use of free convection air-cooled equipment, it is better to be integrated circuits (or other devices) arranged in a longitudinal manner, or arranged in a horizontal manner.

4. Arrange the devices with higher power consumption and higher heat generation near the better position for heat dissipation.

Do not place devices with higher heat generation in the corners and around the edges of the printed board, unless there is a heat sink arranged in its vicinity. In the design of the power resistor as much as possible to choose a larger device, and in adjusting the layout of the printed circuit board so that it has enough space for heat dissipation. 

5. High heat dissipation devices in connection with the substrate should minimize the thermal resistance between them.

In order to better meet the thermal characteristics of the requirements of the chip on the bottom surface can use some thermally conductive materials (such as coating a layer of thermally conductive silicone), and maintain a certain contact area for the device heat dissipation.    

6. In the horizontal direction, high-power devices as close as possible to the edge of the printed board layout, in order to shorten the heat transfer path; in the vertical direction, high-power devices as close as possible to the top of the printed board layout, in order to reduce the work of these devices on the temperature of other devices.

8. more sensitive to the temperature of the device is better placed in the lower temperature region (such as the bottom of the device), do not put it in the heat device is directly above the multiple devices is better in the horizontal plane staggered layout.    

9. Avoid the concentration of hot spots on the PCB,as far as possible, the power is evenly distributed on the PCB board, to maintain the uniformity and consistency of the PCB surface temperature performance.