In this study, the film stacks of foldable AMOLED display are analyzed and designed by finite element analysis (FEA). Controlling the position of neutral plane is one of the key designs for foldable AMOLED display. However, the use of optically clear adhesives (OCA) has a particular effect on the prediction of neutral plane. In the FEA, traction-separation law is chosen to describe the mechanical behavior of adhesives; also the material parameters and failure strength of adhesives are obtained by basic material tests in advance. A 5.99-inch WQHD prototype foldable AMOLED display has been successfully folded more than 100,000 times in dynamic and static mixing at 3mm inward folding radius without damages.

In this study, the film stacks of rollable AMOLED display are analyzed and designed by FEA (finite element analysis). The control for the layer thicknesses and stiffness of film stacks are two of the key designs for rollable AMOLED display. Also, the use of OCA (optically clear adhesives) brings a particular effect to the setting of neutral plane. In the FEA, constitutive model of hyperelasticity is chosen to describe the mechanical behavior of adhesives since the nonlinear elastic behavior and large deformation characteristics of adhesives. A 7.4-inch WQHD prototype rollable AMOLED display has been successfully rolled up more than 15,000 cycles in dynamic at 10mm rolling radius without damages.

AMOLED continues to draw attention for the flat panel display because of its advantages over other displays. Higher resolution, smaller form factor and lower power consumption are three main requirements in the mobile displays, which need faster development and manufacturing capability to meet these requirements for AMOLED displays. In this presentation, Tianma would like to share the latest update to meet the market needs. Moreover, the risks and trade-offs to reach a higher resolution OLED displays with full-screen feature will also be addressed Invited Paper 68-2 / DZ Peng SID 2018 DIGEST • 903 68-2 / DZ Peng Invited Paper 904 • SID 2018 DIGEST Invited Paper 68-2 / DZ Peng SID 2018 DIGEST • 905