By Shannon Davis, Web Editor
Kateeva is out to change the way displays are being made, and during Tuesday’s Silicon Innovation Forum keynote, Kateeva President and COO Conor Madigan, PhD, laid out how their YIELDJet inkjet system is making that happen.
In recent years, OLED displays have captured the imagination of the industry because of the materials’ capability to enable new kinds of form factors, specifically flexible displays. One of the compelling characteristics of OLED is designers can make a display on a thin piece of plastic, freeing them from rigid glass.
Another compelling aspect, Madigan explained, is that OLED displays have fewer subcomponents than their LCD counter parts, so manufacturing cost can be lower. And he believes inkjet technology will play a key role in making OLED more affordable. His company, Silicon Valley-based Kateeva, has focused their efforts on developing an inkjet platform for OLED manufacturing called YIELDJet, a completely different style of inkjet system.
When the concept of flexible OLEDs was first catching on, designers had some significant manufacturing obstacles to overcome, Madigan explained. Designers in R&D were using vacuum-based technique for depositing the films in the OLED structure.
“It was very slow; it required planarization to make a smooth surface, and this didn’t do that well,” said Madigan. “There were many particle defects, and the cost was high.”
Kateeva worked with adapting inkjet technology to this process. Madigan explained that YIELDJet uses individual droplets of ink in a pattern, merges that ink together, and then uses UV lights to cure into a single layer, which has improved the quality of the films.
“Nowadays, we’re focused on broadly enabling low cost, mass production OLEDs with inkjet printing,” Madigan said. “What we’re working on now is a general deposition platform for putting down patterned films at high speed over large areas, realizing the full potential of inkjet technology for the display industry.”
In developing Kateeva’s YIELDJet, Madigan said they focused on how the glass would be handled, how to perform maintenance on a printer system that would be completely enclosed in a nitrogen environment, and managing particle decontamination.
YIELDJet employs a technique that floats a panel of glass on a vacuum and pressure holds, holding it at the very edge, which significantly reduces the size of the system when compared to conventional system which requires glass be moved on a large, often bulky holder. To address accessibility of their complicated system, Kateeva engineers made the system fully automated and able to recover quickly if it needed to be opened up to air.
“It was a new thing to make a printer that was low particle contaminating,” said Madigan. “In one of these printers, you have about ten thousand nozzles, to do fast coating.”
Kateeva was able to develop techniques to monitor all of these nozzles simultaneously, resulting in completely uniform coatings and films.
“The analysis that we’ve done with our customers is that, once they can move to inkjet printing, then you’ll quickly see OLED come down to cost parity and even be below LCD in cost,” Madigan concluded.