How to Improve the Heat Dissipation of Circuit Board?

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, components will fail due to overheating, and the reliability of electronic equipment will decrease. So, the heat dissipation of te circuit board is very important.

1. Add heat-dissipating copper foil and copper foil with large area power supply.

2. Thermal vias can effectively reduce the junction temperature of the device, improve the uniformity of the temperature in the thickness direction of the single board which provide the possibility to adopt other heat dissipation methods on the back of the PCB. Through simulation, it is found that the thermal index of the device is 2.5W, the spacing is 1mm, and the 6x6 thermal vias in the center can reduce the junction temperature by about 4.8℃, and the temperature difference between the top and bottom of the PCB is reduced from the original 21°C is reduced to 5°C. After the thermal via array is changed to 4x4, the junction temperature of the device has increased by 2.2°C compared to 6x6.

3. The exposed copper on the back of the IC reduces the thermal resistance between the copper and air.

4. PCB layout, high power and thermal equipment requirements.

A. Thermal sensitive devices are placed in the cold wind area.

B. The temperature detection device is placed in the hottest position.

C. The components on the same circuit board should be arranged as much as possible according to their calorific value and degree of heat dissipation. Devices with low calorific value or poor heat resistance, such as small signal transistors, small-scale integrated circuits, electrolytic capacitors, etc., are placed at the entrance of the cooling air flow, and devices with large calories or good heat resistance are placed at the most downstream of the cooling air flow.

D. In the horizontal direction, high-power devices are arranged as close to the edge of the circuit board as possible to shorten the heat transfer path. In the vertical direction, high-power devices are placed as close as possible to the top of the circuit board to reduce the impact of these devices on the temperature of other devices when they work.

E. The heat dissipation of the circuit board in the device is mainly depends on air flow, so the air flow path should be studied during the design, and the device or circuit board should be reasonably configured. When air flows, it always tends to flow in places with low resistance. So when configuring devices on the circuit board, please avoid leaving a large airspace in a certain area. The configuration of multiple printed circuit boards in the whole machine should also pay attention to the same problem.

F. Temperature-sensitive devices are best placed in the lowest temperature area such as the bottom of the device. Please do not place it directly above the heating device. It is best to arrange multiple devices on a horizontal surface in a staggered manner.

G. Place the devices with the highest power consumption and heat generation near the best position for heat dissipation. Please do not place high-heating devices on the corners and peripheral edges of the circuit board, unless a heat sink is arranged near it. When designing the power resistor, choose a larger device as much as possible and leave enough space for heat dissipation when adjusting the circuit board layout.

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