PCB Cooling That Is Important, What Skills Can We Do Much More Light?

一．The importance of thermal design

Electronic equipment electrical energy consumed during the period of work, such as radio frequency power amplifier, the FPGA chip, power supply products in addition to useful work, most of the converted into heat. The heat generated by the electronic devices, make the internal temperature rise quickly, if not in time to the heat dissipation, equipment will continue to heat up, the device will fail due to overheating, the reliability of electronic equipment will fall. SMT electronic equipment installation density, effective heat dissipation area is reduced, equipment seriously affect the reliability of temperature, therefore, the study of thermal design is very important.

二．Printed circuit board temperature factor analysis

       Direct cause of the temperature rise of the PCB that is because of the power consumption of the circuit components, electronic devices are exist in different degrees, power consumption calorific intensity varies with the size of the power consumption.

三．Some methods of design the PCB

1.heat through the PCB by itself

2. high heating device and the radiator, heat conduction plate

3. for the free convection air cooling equipment, it is the best to integrated circuit (or other devices) according to the running order, or arranged by horizontal length.

4 .heat dissipation is realized by using rational walk line design As the thermal conductivity of resin in the plate is poor, and copper foil line and hole are good conductor of heat, thus improve the copper foil shaving more than rate and increase the thermal conductivity is a major means of heat.

  5.Five of the same piece of PCB device should as far as possible according to the calorific value of the size and degree of heat partition, calorific value is small or poor heat resistance devices (such as small signal transistor, small-scale integrated circuit, electrolytic capacitors, etc.) on the cooling airflow of the best (entrance) , calorific value and good heat resistance devices (such as power transistor, large scale integrated circuit, etc.) in the most downstream cooling airflow.

 6.in a horizontal direction, high power devices as far as possible close to the edge of the PCB layout, in order to shorten the heat transfer path; In vertical direction, high power devices as far as possible close to the above the PCB layout, so as to reduce the influence of the temperature of these devices work on other devices.

  7 in a horizontal direction, high power devices as far as possible close to the edge of the PCB layout, in order to shorten the heat transfer path; In vertical direction, high power devices as far as possible close to the above the PCB layout, so as to reduce the influence of the temperature of these devices work on other devices.

 8.That is more sensitive to temperature of the device is best placed in the lowest temperature region (such as the bottom of the device), don't put it in heating device, multiple device preferably in a horizontal plane layout.

 9.It will be the highest power consumption and heat the largest device arranged near the radiator best position. Do not place high fever devices around the corners and edges in printed circuit board, unless near its radiator. When designing the power resistance can choose the larger components as far as possible, and when to adjust the PCB layout make have enough cooling space.

 10.RF power amplifier using metal base or LED PCB substrate.

11.The PCB, and avoid hot concentrated, as far as possible will power evenly distributed on the PCB board, keep the PCB surface temperature uniform and consistent performance. Often the design process to achieve strict uniform distribution is relatively difficult, but must avoid too high power density area, so as not to appear too hot affect the normal work of the whole circuit. If there is one condition, the thermal efficiency of printed circuit analysis is necessary, such as some professional PCB design software, increase thermal efficiency index analysis software module in can help designers to optimize the design of the circuit.

四.summary：

 1.select material

    2.to ensure the cooling channels unblocked

    3.components configuration requirements