Large Area Organic Thin Film Coating Using a Micro Multi‑nozzle Jet Head with Side Suction Channels

Abstract

In this paper, we propose a unique micro multi-nozzle jet head to generate a stable column jet flow by applying vacuum suction to the side of a jetting nozzle. The micro multi-nozzle jet head was designed and fabricated to operate in both the jetting and suction modes selectively or simultaneously. The jet head includes eighteen jetting nozzles of 100 mu m diameter, vacuum suction channels, inlets and a nozzle protection outer hole. The whole size of the micro multi-nozzle jet plate is 50 x 20 mm(2). To demonstrate large area organic thin film coating, micro multi-nozzle jet coating was performed on a 5th generation size (1100 x 1300 mm(2)) glass substrate. A poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) solution was selected as a test ink. To uniformly coat an organic thin film, we first investigated the physical parameter conditions such as jetting pressure, head suction pressure, stage moving speed, and coating head printing pitch. The thickness of the coated PEDOT:PSS thin film was 76.86 +/- 3.33 nm and its uniformity (CV) was 4.33%.