Manufacturing printed circuit boards (PCBs) for aerospace electronics requires a high degree of reliability due to the harsh environmental conditions they will operate in. To meet strict operating standards and avoid errors, there are several guidelines that must be followed when designing aerospace PCBs:
- Use High-Quality Components Since maintenance interventions are not possible in mission-critical operations, it is essential to use high-quality materials and components. Anodized aluminum is recommended for its superior thermal conductivity.
- Manage Heat Effectively Effective thermal management is crucial in aerospace PCB design. Some ways to achieve this include using heavy copper technology, thermal vias, materials like Pyralux AP and FR 408, and ensuring reasonable distances between components to facilitate heat dissipation.
- Follow Reference Standards There are established standards for aerospace PCB design, such as IPC 6012DS and AS/EN 9100. Adhering to these standards is necessary for ensuring high performance and reliability.
- Apply Conformal Coating Due to the harsh operating conditions, conformal coating is essential for aerospace PCBs. Coatings like Electrolytic Nickel Gold, ENIG, HASL, and Lead-free HASL offer protection against heat and humidity. Applying an acrylic-based spray after coating protects the PCB from contamination and short circuits.
- Follow Routing Guidelines Choosing the right PCB trace size and ensuring effective heat dissipation are essential. Additionally, avoiding angles greater than 45° on traces ensures uniform signal transmission, and separating components operating at different frequencies maintains signal quality. Proper physical shielding for clock signals and reducing crosstalk are also important.
- Use Flex and Rigid-Flex PCBs Polyamide-based flex and rigid-flex circuit boards are widely used in the satellite, aviation, and aerospace industries due to their adaptability, lightness, heat resistance, and durability. They offer high resistance to vibrations and shocks and work well in limited space applications.
- Test Rigorously Robust testing is essential to ensure reliable PCB design for aerospace applications. Testing should account for working in zero gravity in a vacuum and extremes of temperature, depending on whether the PCB will operate on a low-orbit or geostationary satellite.
In summary, aerospace PCB design and manufacturing must prioritize high reliability in harsh operating conditions. From design to material selection, following guidelines can ensure failure-free operation and resistance to g-force vibrations, thermal issues, and other challenges.