Print Process Development for Ag-Ink Thermoformable Conductive Traces Utilizing Direct Write technique for In-Mold Printed Electronics

Wire harnesses contribute a significant portion of the weight on the automotive platform. In-mold electronics provide weight reduction pathways by integrating the conductive traces into the automotive interior body panels. Additive print processes provide a method to fabricate circuits through soft tooling using a number of conductive and dielectric materials. However, the print-process recipes and process-property interactions on thermo-formable flexible substrates are scarce. In this paper, a process recipe has been developed by studying different printing and post printing parameters for stretchable conductive silver ink via the direct write technique. Direct write methods have been implemented on the nScrypt platform. A thermo-forming capable high-impact polymer sheet (HIPS) substrate has been used for the study. The printed traces have been sintered post-print. The cross-section of the printed lines has been measured using white-light interferometry. The effect of the process parameters on the printed line resistivity has been studied.