The demand for flexible and stretchable electronic devices is rapidly increasing, particularly in applications such as wearables, biomedical sensors, and conformable displays. Aerosol Jet Printing (AJP) has emerged as an advanced additive manufacturing technique capable of directly depositing functional inks onto various substrates, including glass slides, FR4, PET, and other flexible, temperature-sensitive materials. However, achieving high-performance, reliable interconnects with AJP often necessitates high-temperature sintering, which can compromise substrate integrity. This study systematically investigates a low-temperature sintering strategy for AJP-printed silver nanoparticle interconnects on flexible substrates. Optimization of sintering parameters identified 170 °C for 60 min as the optimal condition, yielding a resistivity of 1.12 × 10−6 Ω·m. Mechanical and electrical reliability were assessed through bending and adhesion tests. After bending, the resistivity slightly increased to 1.20 × 10−6 Ω·m, indicating a minimal impact on conductivity. Despite this small increase, the interconnects retained their flexibility, with no signs of failure or breakage. Additionally, the interconnects withstood adhesion testing, demonstrating strong interfacial stability. These results confirm that the optimized sintering process enables the fabrication of conductive, flexible, and mechanically resilient interconnects. This low-temperature sintering approach enhances AJP-printed devices’ reliability on temperature-sensitive substrates and provides a structured framework for optimizing processing conditions in flexible electronics manufacturing.