OLED Encapsulation Stack with Moisture-Absorbent Layer

The encapsulation structure is divided into multiple functional layers: an inorganic encapsulation layer (first layer) that provides primary barrier protection, and an organic encapsulation layer (second layer) that provides additional protection and flexibility. This segmentation allows each layer to perform its specific function optimally, with the inorganic layer blocking moisture and oxygen penetration while the organic layer provides structural support and additional barrier properties.

The patent employs a composite encapsulation structure combining inorganic and organic materials. The inorganic encapsulation layer (e.g., aluminum oxide, silicon oxide) provides superior moisture and oxygen barrier properties, while the organic encapsulation layer (e.g., polyimide, epoxy resin) provides mechanical flexibility and additional protection. This composite approach leverages the complementary strengths of different material classes to achieve enhanced overall protection.

The moisture-absorbent material is selectively incorporated into specific regions of the encapsulation structure rather than being uniformly distributed throughout the entire device. Specifically, it is added to the organic encapsulation layer at strategic locations where moisture ingress is most likely to occur, such as near the edges or in areas with higher stress concentration. This localized approach provides effective moisture protection while minimizing the total amount of expensive moisture-absorbent material required.

Instead of using moisture-absorbent material throughout the entire encapsulation structure, the patent applies it partially or excessively only in critical areas where moisture protection is most needed. This partial action approach achieves sufficient protection against moisture ingress while avoiding the excessive cost that would result from comprehensive use of moisture-absorbent materials in all regions.