Synergistic Effect of Temperature Cycling and Atomic Oxygen on the Parallel Gap Resistance Welding Joint in GaAs Space Solar Panel

Spacecraft in near-Earth orbits endure a multifaceted space environment, predominantly influenced by orbital temperature cycling and atomic oxygen (AO). The operational reliability of solar panels, essential for power generation, significantly impacts the longevity of these systems. While the panels’ solar cells are robust, their connecting joints represent a critical point of potential failure, necessitating thorough analysis. Despite extensive research into the reliability of space-bound systems, studies analyzing the combined effects of temperature changes and AO are scarce. This study employs parallel gap resistance welding (PGRW) to forge connections between the pure silver interconnectors and the rear electrodes of GaAs solar cells. The resulting joints undergo separate and combined temperature and AO testing to elucidate the synergistic influence on joint dependability. The tests reveal that joints on the solar cell’s rear electrode maintain integrity against temperature fluctuations when partially melted interfaces are present. AO primarily induces superficial peeling and a reduction in the interconnector’s thickness, leading to fractures in PGRW joints with previously melted interfaces. This research highlights that the detrimental synergy of temperature oscillations and AO can be substantially mitigated through the enhanced bonding of the interface joining the interconnector and the solar cell electrode.