A number of process technologies that enhance the characteristics of solid surfaces have been established. Neglected for many years the surface processing method using ultraviolet radiation has gained wide acceptance throughout the organic electronics industry. UV Cleaning has become an indispensable technology to manufacture OLEDs as it provides a simple, inexpensive and fast method of obtaining ultra-clean surfaces. Being an atmospheric, dry process at room temperature it provides a simple, inexpensive and fast method of modifying and obtaining ultra-clean surfaces. Modification directly enhances the adhesion power of the treated surface, while cleaning gets rid of residual organic contaminants.
Commonly used substrate materials are glass, polymers, metals and ceramics. For this application mainly high output low pressure mercury lamps are used which emit primarily at 185 nm and 254 nm. The oxidation reaction to decompose organic compounds is proceeded first by cracking molecular bonds of the contaminants and oxygen molecules utilizing the 185 nm wavelength. As a result excited molecules with an increased hydrophilic nature and ozone are formed. Simultaneously the 254 nm wavelength cracks the ozone into activated oxygen. Radicals such as -OH, -COO, -CO and -COOH react with the atomic oxygen and form volatile components (CO2 and H20) which desorb from the surface and are flushed out of the process chamber. After exposure to UV light, the surface of the substrate has been cleaned or modified and the bonding force of adhesives will rise which is of specific interest in OLED encapsulation.
MBRAUN Ultraviolet Ozone Systems are widely used in the organic electronic and semiconductor industries as well as in scientific research fields including biology, chemistry, physics and materials science. These systems have been specifically designed for being integrated into gloveboxes and therefore feature a hermetically sealed process chamber as the resulting volatile components harm OLED devices. Furthermore special measures have been taken to remove the ozone from the exhaust process gas by catalytic reaction.
Please contact us for more information regarding our UV Cleaner process tools.