Material selection of avionics PCB

Material selection of avionics PCB

Aerospace electronics requirements

Circuit boards are almost everywhere in all equipments, machinery,  and vehicles used today. Broadly speaking, we can classify these systems as business systems or critical systems. Commercial systems include cellular phones, computers, televisions and household appliances. The critical system is a system with more stringent requirements, because failures may lead to terrible consequences and even loss of life. The PCBs that make up these critical systems usually have to withstand higher performance standards, such as IPC-6011, which requires uninterrupted service for Class 3 high-reliability electronic products.

The board used in the avionics system must comply with the regulations. IPC-6012DS Space and military avionics application appendix of IPC-6012D, qualification and performance specifications for rigid printed boards or IPC-6013D flexible/rigid-flex printed boards. In addition to these regulations and standards, the development of avionics systems must also include a documented framework in the quality control process, AS9100D, a standard quality management system (QMS) and risk analysis. Since avionics may encounter difficulties encountered in orbit or on interplanetary aviation platforms, such supervision is required.

Aviation PCB material selection

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. For rigid boards, this is even more of a threat, because their bendability range is much tighter than flexible boards.

Temperature cycle 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.

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.

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.