Foldable Display Support Substrate for Outer-Area Stress Relief

The support substrate is divided into multiple segments by introducing openings (e.g., circular openings, slots, or grid patterns) that segment the continuous structure. This segmentation allows stress to be distributed across multiple paths rather than concentrating at a single location, thereby preventing crack formation while maintaining overall structural strength during folding operations.

The support substrate is designed with non-uniform properties where the thickness and material composition vary in different regions. The outermost area (folding area) uses thinner or more flexible material to accommodate stress during folding, while the inner area maintains thicker, more rigid material for structural support. This local differentiation prevents stress concentration at the folding interface while preserving overall strength.

The design introduces a dimensional variation in the support substrate by changing the thickness parameter across different regions. The outermost area has reduced thickness to increase flexibility and accommodate smaller folding radii, while the inner area maintains greater thickness for structural integrity. This dimensional change allows compact folding without excessive stress concentration.

The material parameters (thickness, elasticity modulus) of the support substrate are optimized differently in various regions. The outermost area uses materials with lower elasticity modulus and reduced thickness to enhance flexibility and reduce stress during tight folding, while the inner area uses higher elasticity modulus materials with greater thickness for structural support. This parameter optimization enables compact folding while controlling stress levels.