Flexible display device and manufacturing method thereof

A flexible display device, comprising:

• a backplate;
• a flexible display panel, wherein the flexible display panel is bent at a preset position to form a first plane part, a bending part, and a second plane part, and the bending part is located between the first plane part and the second plane part;
• wherein the preset position comprises a first bending point located on a surface where the bending part meets the first plane part and a second bending point located on a surface where the bending part meets the second plane part, the first plane part lies on a first plane, and the first bending point and the second bending point lie on a second plane perpendicular to the first plane;
• and
• wherein a distance between the first bending point and the second bending point is H, and on the second plane, a radius of curvature of the bending part is greater than H/2,
• wherein the flexible display panel is disposed on the backplate, a first backplate is disposed on the backplate corresponding to the first plane part, the first plane part is located on the first backplate, a groove part is defined on the backplate corresponding to the bending part, the bending part is disposed corresponding to the groove part, a second backplate is disposed on the backplate corresponding to the second plane part, and the second plane part is located on the second backplate;
• wherein the second plane part is bent to one side of the first backplate towards the first plane part, and a design h L of the groove part before bending satisfies a following formula:
• L=απ(H−h)/2;
• wherein α is a bending process accuracy corrected value, H is a distance between the first bending point and the second bending point, and h is a thickness of the flexible display panel.