Performance of Printed Circuit Structures Fabricated with Hybrid Additive Manufacturing Technologies for High-Impact Applications

This work explores the convergence of additive manufacturing (AM) technologies and investigates the survivability of printed circuit structures (PCSes) in extreme environments that sustain high-impact shock loads. The substrates of the PCSes were manufactured by additive friction stir deposition (AFSD), a solid-state metal AM process. The as-deposited (AD) condition of AFSD processed AA6061 was machined, anodized, and subjected to circuit printing to create a functional PCS. Split-Hopkinson pressure bar configurations were used to shock load PCS specimens in triplicate and characterize the compressive strength of the AA6061 AD material at high strain rates, which was compared to its quasi-static behavior. Cyclic shock loads of 35 kg, an acceleration load higher than expected in near-field applications, were implemented to uncover failure mechanisms and demonstrate instances of circuit survivability in PCS specimens. Results showed that AD AA6061 substrate material exhibited no failure throughout cyclic shock loads and demonstrated increased compressive strength at dynamic strain rates of 2000 s −1 compared to its quasi-static comparison at 0.001 s −1 . The trace material exhibited various failure mechanisms such as hardware ejection and trace cracking, flaking, and peeling. However, there were instances where circuit traces maintained continuity within a 20% tolerance throughout all 10 cyclic shock loads, which demonstrates the potential for PCS survivability in extreme environments and high-impact applications.