Organic Light-emitting Device Packaging Technology

OLED has the characteristics of low power consumption, light weight, high brightness, wide view, high contrast and high response speed. And it can realize flexible display. Domestic and foreign scholars have done many researches on it and have achieved great success. However, there still remain many problems, among which the key point is how to prolong the lifetime of OLED by using a certain kind of encapsulation material.Traditionally, OLED is encapsulated by UV curing epoxy resin. However, vapor and oxygen can penetrate into OLED encapsulated by UV curing epoxy resin, which has a negative effect on the lifetime of OLED. As a result, a new method of encapsulation should be worked out to better separate OLED from vapor and oxygen in order to prolong its lifetime.First of all, mass spectrometry is used to measure the gas permeability of UV curing epoxy resin and vacuum sealing wax. The results show that the permeability of vacuum sealing wax is about one order of magnitude higher than UV curing epoxy resin. This reveals the prospect of prolonging the lifetime of OLED by using vacuum sealing wax as the encapsulation material.Additionally, the method of the encapsulation by vacuum sealing wax is discussed, including the production of sealing layer and the technology of heating package. During the fabrication of sealing layer, the method of waxing and the technology of deflation treatment have also been tested. The method of local heating by laser has been used during the process of vacuum sealing wax encapsulation. It is the power of light rays and the radius of light spot emitted by the semiconductor laser device that has been measured. Besides, the overall heating method has also used to realize the encapsulation of OLED by vacuum sealing wax.Both UV curing epoxy resin and vacuum sealing wax have been used to encapsulate OLED and the lifetime has been measured separately. The results show that the lifetime of OLED encapsulated by UV curing epoxy resin is 2.4 times longer than that encapsulated by vacuum sealing wax, which corresponds to the results forecasted.At the end, problems and the improvement discovered during the research have been discussed.