OLEDs provide a superior display technology to LCDs. Significant advantages include: truer color, better contrast ratio, and lower power—on a thinner and more flexible screen.
And because OLEDs have a simpler device structure, they can potentially be manufactured at a much lower cost than LCDs.
OLED production begins by creating the backplane (switching and driving circuitry) on a substrate, depositing and patterning the organic layers, and then encapsulating the structure to protect it from physical damage, as well as oxygen and moisture damage. Where an LCD screen requires seven distinct device components, an OLED screen has only four.
Today’s smart phone OLED displays are routinely made using a vacuum evaporation process, which requires a fine metal mask to pattern the organic layers. Although a simple process and utilized in manufacturing today’s rigid mobile displays, scaling it to mass produce flexible and large-scale displays has proven extremely challenging. Yields are unacceptably low—largely due to particulate contamination—and production costs prohibitive.
The ideal alternative technology is inkjet printing. In R&D, the approach has produced beautiful OLED panels. More importantly, it enables very high throughput, process quality and process flexibility – advantages that could ease today’s critical manufacturing bottlenecks for flexible and large-size OLEDs.
However, although long proven in other industries, inkjet printing has not successfully transitioned to mass-produce OLED displays.
To make it work, formidable manufacturing obstacles must be overcome. They include defects, reliability, and device performance, as well as productivity and cost. Substantial R&D has been completed on the core technologies needed to apply inkjet printing to OLED manufacturing, including: precision stage and motion control, high accuracy drop placement, fine print head control, and back-print algorithms, as well as advanced monitoring solutions and maintenance protocols.
But this is not enough.
Without a rigorous re-think, mass producing flexible and large-size OLEDs will remain economically unviable. And building on 15+ years of inkjet OLED R&D, it’s clear that the re-think must involve disruptive techniques to control the process environment, minimize particulates, and expand the process window.
This calls for a new class of inkjet manufacturing equipment solution.