Considerations in printing conductive traces for high pulsed power applications
The effect of different substrates, inks and sintering methods on the breakdown of a printed conducting trace subjected to a single millisecond-range pulsed current was investigated. The breakdown current density (Jb) of a trace was found to be strongly dependent on substrate thermal diffusivity, which dictates the peak temperature and the cooling rate of the trace. As an example, a 102% increase in average Jb was observed in switching substrate from glass slide to sapphire. Different inks resulted in significant Jb deviation due to their distinct microstructure difference. Traces with dense microstructure exhibited an average Jb that is 42% higher than their porous counterpart. Different sintering methods also resulted in varying Jb. Traces thermally sintered on a hot plate demonstrated an average Jb that is 74% higher than their laser sintered counterpart. Finally, a simple concept that effectively dissipates heat from the trace was explored. It prevented breakdown when the traces were subjected to a single firing pulse used in detonation. Results from this work offer important considerations in printing conductive traces for high pulsed power applications.