Flexible OLED Encapsulation Structure for Moisture Barrier and Bending

The encapsulation structure is divided into multiple thin layers (first inorganic layer, first organic layer, second inorganic layer, second organic layer) instead of using a single thick encapsulation layer. This segmentation provides effective moisture and oxygen barrier protection while maintaining flexibility, as each thin layer can conform to substrate bending without cracking or delamination.

The patent employs a composite encapsulation structure combining different materials with complementary properties: inorganic layers (such as aluminum oxide, silicon oxide) provide excellent barrier properties against moisture and oxygen penetration, while organic layers (such as polyimide, polyethylene terephthalate) provide flexibility and adhesion. This composite approach achieves both durability and flexibility simultaneously.

Instead of using a single thick encapsulation layer, the structure segments the total thickness into multiple thinner alternating inorganic and organic layers. This segmentation achieves equivalent or superior barrier performance through the cumulative effect of multiple interfaces that block diffusion paths, while each individual thin layer maintains flexibility and ability to conform to bent substrates.

The patent employs thin film encapsulation where each inorganic and organic layer has controlled thickness (typically nanometer to micrometer scale) to provide adequate barrier protection while maintaining flexibility. The thin film structure allows the encapsulation to bend with the flexible substrate without cracking, unlike thicker rigid encapsulation layers.

The encapsulation structure is segmented into repeating units of inorganic-organic layer pairs. This modular segmentation provides systematic barrier protection where each unit contributes to overall performance, while the repetitive pattern simplifies manufacturing processes and quality control compared to irregular multi-layer designs.

The inorganic layers serve multiple functions: providing primary barrier against moisture and oxygen penetration, serving as adhesion promoters between organic layers, and acting as planarization surfaces. The organic layers simultaneously provide flexibility, adhesion, and secondary barrier properties. This multi-functionality reduces the need for additional specialized layers, managing complexity.