Process–Performance Mapping of Aerosol Jet Printed Silver Traces: From Thermal Curing Parameters to RF Characteristics of Microstrip Devices

Abstract This paper presents a systematic methodology for quantifying the relationship between thermal curing parameters and radio-frequency performance in aerosol jet printed conductive traces on FR-4 substrates. Using microstrip transmission lines as diagnostic vehicles, we establish a multilevel correlation between thermal curing conditions, silver trace morphology and electrical properties, transmission-line RF characteristics, and antenna performance. Under selected practical curing conditions, the DC resistance of the printed silver traces decreased from 11.2 Ω for the low-temperature curing condition to 4.6 Ω for the high-temperature curing condition, indicating enhanced silver densification with increased thermal input. However, excessive thermal exposure may compromise FR-4 substrate reliability, suggesting that the optimal fabrication window requires a balance between conductor conductivity and substrate thermal stability. The transmission-line characterization further reveals that thermal curing conditions significantly influence impedance behavior and signal transmission characteristics, providing intermediate RF-level information for predicting antenna responses. These material-level signatures are correlated with the performance of inset-fed microstrip patch antennas fabricated under representative process conditions, demonstrating the effectiveness of the diagnostic transmission-line approach. The established process window is further evaluated through fabrication of a 4.8 GHz 2×1 patch array, demonstrating the applicability of the process–performance characterization approach to a higher-frequency and structurally more complex RF device.