Process Performance Interaction of In-Mold Electronics for Signal-Processing Applications

The use of in-mold electronics architectures opens new possibilities in the integration of wire harnesses and human-machine interfaces into body wall plastic for the automotive platform in conjunction with additive fabrication. Process-property interactions of additively fabricated functional circuits have not been sufficiently understood in the presence of thermoforming to make informed choices of process parameters based on known design and material parameters. This study examines the process-performance interactions of thermoformable substrates. Previous research endeavors have primarily concentrated on the advancement process development of stretchable conductive inks that are well-suited for thermoforming applications. In this paper, a test vehicle with stretchable conductive ink is used on the nScrypt platform, and the samples are cured using a conventional thermal oven. Thermoforming has been pursued at various temperatures and times. The electrical properties of conductive traces have been compared before and after thermoforming. The interaction of processes and performance on two substrates materials including polycarbonate and high-impact polystyrene has been compared. The thermoforming process has been validated by printing a functional circuit (integrator) whose data is compared to simulated data using LTspice.