OLED Encapsulation via Ring-Shaped Metal Barrier

The patent employs a composite encapsulation structure combining inorganic layers (such as aluminum oxide, silicon oxide) with organic sealant and adhesive materials. The inorganic layers provide dense barrier properties to block moisture and oxygen permeation, while the organic materials provide sealing and bonding functions. This composite approach overcomes the limitation of organic materials alone which have large molecular gaps allowing permeation.

The encapsulation structure is divided into multiple functional layers: inorganic barrier layers, organic sealant layers, and moisture absorbent layers. Each layer performs a specific function - the inorganic layers block permeation, the sealant provides sealing, and the moisture absorbent captures any residual moisture. This segmented approach addresses the permeation issue by creating multiple barriers rather than relying on a single organic material layer.

The patent applies different material properties to different regions of the encapsulation structure. The inorganic layer provides dense barrier properties in the central area where permeation blocking is most critical, while the edge regions incorporate flexible organic sealant materials and moisture absorbent layers that can accommodate stress without cracking. This local differentiation of material properties maintains both barrier performance and edge integrity.

The patent incorporates moisture absorbent materials and flexible sealant layers beneath and around the inorganic barrier layer to cushion against stress concentration. These layers act as buffer zones that absorb mechanical stress and prevent crack propagation at the edges, thereby maintaining the integrity of the encapsulation structure while preserving the barrier function.

The patent uses a composite encapsulation structure with inorganic barrier layers, organic sealant layers, and moisture absorbent layers working together. This composite design provides comprehensive protection against moisture and oxygen while maintaining a relatively streamlined structure that does not excessively complicate the device architecture.

The encapsulation structure performs multiple functions simultaneously: the inorganic layers provide barrier protection, the organic sealant provides sealing and bonding, and the moisture absorbent materials capture residual moisture. This multi-functionality allows a single encapsulation system to address multiple degradation mechanisms without requiring separate protective systems for each function.