Inkjet Printing of SiO 2 Hollow Spheres/Polyimide Hybrid Films for Foldable Low-k ILD

摘要

We demonstrate inkjet printing as a viable method for flexible interlayer dielectrics (ILDs) films with a low dielectric constant, excellent mechanical characteristics, and thermal properties in foldable organic light emitting diodes (OLEDs). SiO_(2)hollow spheres (SHSs)/polyimide (PI) hybrid films were printed by SiO_(2)coated polystyrene (PS) ink and PI ink. The relative permittivity of the hybrid films decreased from 3.45 to 1.87. The thermally stable PI fims maintained their weight below 500 °C from the TGA result. The dielectric constant and current density retained their properties after 50,000 cycles of bending at a 1 mm bend radius. We propose that the inkjet printing of SHSs/PI hybrid films described herein is a promising approach for flexible ILDs in foldable OLEDs.