Flexible Cover Plate Composite Structure for Foldable Displays

The patent uses a composite structure consisting of a first cover plate layer (transparent polyimide or PET) and a second cover plate layer (ultra-thin glass) with different material properties. The first layer provides flexibility and folding performance, while the second layer provides hardness and impact resistance. This composite material approach resolves the contradiction by combining materials with complementary characteristics rather than using a single material that must compromise between thinness and strength.

The patent applies different thicknesses of the second cover plate layer in different regions: a first thickness in the bending area and a second thickness (greater than the first) in the non-bending area. This local quality variation allows the bending area to maintain flexibility for folding while the non-bending area provides enhanced protection and mechanical strength, thus resolving the contradiction between folding performance and impact resistance.

The patent combines a flexible polymer layer (CPI or PET) with an ultra-thin glass layer to create a composite cover plate. The glass layer provides the necessary surface hardness and scratch resistance, while the polymer layer maintains flexibility for folding. This composite approach eliminates the need to choose between thinness for folding and hardness for protection.

The second cover plate layer (ultra-thin glass) is applied with varying thickness: thinner in the bending area to maintain flexibility and thicker in the non-bending area to maximize surface hardness and protection. This localized thickness variation ensures that surface hardness is enhanced where needed without compromising folding performance.