Abstract We have investigated thin-film encapsulation layers that can be stable without the occurrence of cracks even when the layer is repeatedly folded with a small radius down to 1 mm. The folding stability criteria were also identified for the cases where the encapsulation layer deviates by a certain distance from the stress neutral plane inside a foldable device. An organic-inorganic multilayer structure having the inorganic layer thickness of 5 nm has always been shown to be stable against repeated folding with a radius of 1 mm even though the multilayer is located far from the stress neutral plane. In addition, the folding stability of the organic-inorganic multilayer encapsulation layer was evaluated when contaminant particles were present on the surface of foldable devices. To this end, the step coverage over the contaminant particles and the folding-stability criteria of the encapsulation structure were investigated. It was confirmed that the organic-inorganic multilayer structure was stable to repeated folding in a radius of 1 mm when the coating angle covering the particles was loosened to 140° or more through planarization and thin-film encapsulation.

中文翻译：

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可折叠有机发光二极管薄膜封装层的折叠稳定性标准

摘要 我们研究了薄膜封装层，即使在以小半径重复折叠至 1 mm 的情况下，薄膜封装层也能保持稳定而不会出现裂纹。对于封装层偏离可折叠设备内的应力中性平面一定距离的情况，还确定了折叠稳定性标准。具有 5 nm 无机层厚度的有机-无机多层结构一直被证明可以稳定地抵抗半径为 1 mm 的重复折叠，即使该多层结构远离应力中性面。此外，当污染物颗粒存在于可折叠设备的表面时，评估了有机-无机多层封装层的折叠稳定性。为此，研究了污染物颗粒上的阶梯覆​​盖和封装结构的折叠稳定性标准。通过平面化和薄膜封装，当覆盖颗粒的涂层角度松开至140°或更大时，有机-无机多层结构对于以1mm半径重复折叠是稳定的。