Ultrasonic Spraying System for OLED Manufacturing
The ExactaCoat Inert ultrasonic spray system is well developed for research and development for organic light emitting diodes, or OLEDs. Depositing the organic layer onto susbtrates requires a very uniform, precise method of deposition. The ExactaCoat Inert is a fully inert glovebox spray system, capable of 1 ppm oxygen atmosphere processing, and is fully programmable. It is built for continuous operation with a constant positive pressure environment, using nitrogen, argon or helium. The system allows the operator to control the oxygen and moisture levels in the glove box, aiding in the protection of the sensitive materials that OLEDs are constructed of.
The programmable PLC controlled three-axis precision ultrasonic coating system is fully integrated into the glovebox, providing full range of motion for easy and precise coating. Sono-Tek’s ultrasonic nozzles provide a soft atomized spray with independent air shaping control providing repeatable thin film precision coatings to increase the cell’s efficiency on various OLED substrates. This system works great with small molecule OLED materials that are solution processable because the ultrasonic technology allows for uniform droplet size, producing repeatable deposition densities and thicknesses.
Applying organic layers to the substrate in the manufacture of OLEDs is usually done in one of three ways:
- Vacuum deposition or vacuum thermal evaporation (VTE)
- Organic vapor phase deposition (OVPD)
- Inkjet printing
Sono-Tek ultrasonic spray technology has been proven effective as a cost effective alternative to vacuum and vapor deposition processes, and provides more uniform thin films with less overspray than inkjet printing methods, reducing cost due to waste.
Ultrasonic Coating Benefits:
- Independent liquid and air shaping flows allow for ideal thickness and wetness to be achieved
- Inert atmosphere allows for sensitive OLED materials to be safe from oxygen and moisture
- Fully programmable XYZ axis system allows for total control of coating area
- Ultrasonic vibrations keep solids in suspension within the solution
- Very precise, accurate, and repeatable results obtained to give high efficiency cells
- Reduces process waste and overspray
- Increases process efficiency and makes OLEDs more economically feasible
The ExactaCoat Inert system is used to coat the organic layers in an active matrix. Suspensions for hole injecting, hole transport, hole blocking or electron transport are deposited using ultrasonic spray. Copper, Aluminum, Zinc or other suspensions are uniformly dispersed in micron thick layers. Sono-Tek is committed to providing OLED production equipment that enables manufacturers to achieve the highest possible uniformity and accuracy.