Drop feature optimization for fine trace inkjet printing

This paper presents results of an empirical investigation on drop feature optimization, subsequent fine trace printing and influence of sintering atmosphere on printed traces on polyimide substrate with Ag nanoparticle ink. The impact of printing parameters such as waveform features, jetting voltage and printhead height on drop formation and fine trace printing is investigated. The experiments revealed that drop diameter decreased by 33% after decreasing jetting voltage and overall waveform duration to a minimum functional range. From further studies, it is found that to print accurate fine traces an optimum drop spacing value in consideration with drop count should be selected which prints traces close to the required trace width dimensions. Based on these optimizations, trace width of 30 ± 2 μm can be printed with minimum pitch of 35 μm. Sintering progresses faster under air compared to nitrogen due to the efficient removal of the organic capping agents. The resulting sheet resistance under air and nitrogen were 0.1312 Ω/π and 1.8586 Ω/π respectively.