Heat dissipation mode of PCB circuit board

1.When there are a few devices in the PCB that diverge and conduct (three consecutive), a heat sink or a conductive tube can be added to the heating components. When the temperature cannot be lowered, a radiator with a fan can be used to enhance the heat dissipation effect. When the amount of heat-generating components is more than 3, a large heat shield (board) can be used. It is a special heat sink customized according to the position and height of the PCB heat-generating components. The heat sink is integrated but the heat dissipation effect is not good due to the poor consistency of the height when the components are mounted and soldered. Generally, a soft thermal phase change attenuation pad is added on the surface of the component to improve the heat dissipation effect.

2.Currently widely used PCB boards have excellent electrical properties but poor heat dissipation. As a heat dissipation method for highly heat-generating components, it is almost impossible to expect heat to be conducted by the PCB itself, but to dissipate heat from the surface of the component to the surrounding air. However, as electronic products have entered the era of component miniaturization, high-density mounting, and high-heat assembly, it is not enough to dissipate heat only by the surface of the component. At the same time, due to the large number of components mounted on the PCB circuit board surface, a large amount of heat generated by the components is transferred to the PCB. Therefore, the best way to solve the heat dissipation is to improve the heat dissipation capability of the PCB itself.

3.Due to the poor thermal conductivity of the resin in the PCB sheet, and the copper foil lines and holes are good conductors of heat, increasing the copper foil residual rate and increasing the heat conduction holes are the main means of heat dissipation.

4.The components on the same PCB should be arranged as much as possible according to the amount of heat generated and the degree of heat dissipation. Components with low heat generation or poor heat resistance (such as small signal transistors, small-scale integrated circuits, electrolytic capacitors, etc.) should be placed in the most Upstream (at the entrance), components with high heat generation or good heat resistance (such as power transistors, large-scale integrated circuits, etc.) are placed at the most downstream of the cooling airflow.

5.In the horizontal direction, high-power components should be arranged as close to the edge of the printed PCB board as possible to shorten the heat transfer path;
In the vertical direction, high-power components are placed as close to the top side of the PCB board as possible to reduce the impact of these components on the temperature of other components.

6.The temperature-sensitive components are best placed in the lowest temperature area (such as the bottom of the device). Do not place it directly above the heat-generating components. Multiple components are preferably staggered on a horizontal plane.

7.The heat dissipation of PCB mainly depends on the air flow, so the air flow path should be studied during the design, and the components should be reasonably configured. When air flows, it tends to flow in a place with low resistance, so when configuring the components on the printed circuit board, avoid leaving a large airspace in a certain area.

8.Avoid the concentration of hot spots on the PCB, and distribute the power as evenly as possible on the PCB to maintain uniform and consistent temperature performance on the PCB surface. It is more difficult to achieve strict uniform distribution during the design process, but it is necessary to avoid areas with too high power density to avoid excessive hot spots that affect the normal operation of the entire circuit. If possible, it is necessary to analyze the thermal efficiency of printed circuits. For example, some professional PCB design software can help designers optimize circuit design.

9.When designing a PCB board,place the components with the highest power consumption and heat generation near the best heat dissipation location. Do not place components with high heat generation at the corners and peripheral edges of the printed PCB board, unless a heat sink is arranged near it.

10.High heat dissipation components should minimize the thermal resistance between them when connected to the PCB board. In order to better meet the thermal characteristics requirements, some thermally conductive materials (such as a layer of thermally conductive silicone) can be used on the bottom surface of the chip, and a certain contact area is maintained for the components to dissipate heat.

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