Aerospace PCB assembly design and requirements

Important guidelines for PCB design in aviation and aerospace

Aerospace and avionics must withstand the extreme conditions of outer space. Therefore, compared with conventional commercial PCBs, they require a special structure and design. Designers and manufacturers of these PCBs must keep some precautions in mind when designing them.

Aviation printed circuit board

For beginners, their design must be more powerful, which requires the implementation of specific layout and design techniques. Making circuit boards for airplanes is a difficult and time-consuming task. Pay special attention to the thermal management of the aviation PCB, while considering the special design and layout techniques of high-frequency RF components. Therefore, in order to manufacture printed circuit boards for aerospace equipment, basic design and layout must be considered to make them more superior.

This means that the designer must define the correct board material, specify precise drilling diagrams, keep neat assembly precautions, keep stacking recommendations for layouts, add extra cushions for mechanical dimensions and holes, and use the correct termination method And perform a pre-layout simulation. The designer of the aircraft circuit board must also verify the impedance calculation, shield the signal, separate the ground plane and the power source, and then maintain the correct aspect ratio.

Special PCB design and layout need to pay attention to issues
1. Resistance to vibration and shock
The energy required to launch a vehicle into space is enormous. Therefore, almost all circuit boards are subject to vibration and/or impact, which may put pressure on or on the circuit board. Connector. For rigid boards, this is even more of a threat, because their bendability range is much tighter than flexible boards.

2. Temperature cycling resistance
Whether inside or outside an aerospace platform, extreme temperature fluctuations can be part of normal operations. This must be taken into account when selecting PCB materials and ensure that the critical temperature parameters of the circuit board, such as the glass transition temperature (Tg), are not violated.

3. Humidity resistance
Generally, temperature is inversely proportional to humidity. However, in a closed environment such as a space, vehicle humidity may become a problem. If so, electronic equipment and circuit boards will malfunction due to moisture. Therefore, moisture resistance is an ideal property of PCB materials.

4. Anti-radiation
Depending on the location of the spacecraft in the Earth’s atmosphere, it may have to withstand radiation or harmful RF. Since these types of interference can severely disrupt communications and other circuit operations, circuit boards need to be able to resist them.

When selecting PCB materials for aerospace systems, the above attributes should be considered.