Polymer surface texturing for direct inkjet patterning by atmospheric pressure plasma treatment

It would be beneficial if the substrate surface were treated to have hydrophobic properties, in order to keep the line pattern fine during the inkjet processing, while at the same time having improved adhesion properties on the substrate. In this study, a polyimide surface was textured using atmospheric pressure plasma treatment for fine line metal inkjet printing by micromasking the surface followed by etching the polyimide surface selectively. The water contact angle on the textured polyimide film was measured to be over 100 degrees, showing that the surface was hydrophobic. When the textured polyimide surface was printed on using an electro-hydro-dynamic inkjet for Ag line printing, not only fine line Ag printing, but also improved adhesion of Ag to the polyimide surface could be obtained while maintaining excellent resistivity. The improved adhesion properties in addition to the fine line patterning afforded by texturing the polyimide surface were caused by the increased surface contact area between the metal ink and the polyimide surface during the annealing of the Ag line.