Flexible substrate, method for producing the same and flexible display device

1. A flexible substrate comprising:

a flexible layer,

wherein the flexible layer has a plurality of notches which have a first maximum width along a stretch direction in a stretched state of the flexible layer and have a second maximum width along the stretch direction in an unstretched state of the flexible layer,

wherein the first maximum width is greater than the second maximum width, and

wherein the flexible substrate further comprises: fillers in the notches, wherein there is a weak adhesion interface between the flexible layer and the fillers.

2. The flexible substrate of claim 1 , wherein the flexible layer and the fillers are made from different materials, respectively.

3. The flexible substrate of claim 1 , wherein the plurality of notches further comprises a plurality of groups of notches and each group of the plurality of groups of notches comprises a plurality of notches separated from each other and arranged linearly in the flexible layer.

4. The flexible substrate of claim 3 , wherein in the stretched state of the flexible layer, each group of notches are communicated together to form a hole.

5. The flexible substrate of claim 4 , wherein the hole has a rhombic shape in a cross section thereof parallel to the flexible layer.

6. The flexible substrate of claim 3 , wherein the plurality of groups of notches comprise rows of notches and columns of notches that are arranged alternately in the flexible layer and separated from each other.

7. The flexible substrate of claim 1 , wherein depths of the notches in the flexible layer are less than or equal to thickness of the flexible layer.

8. The flexible substrate of claim 1 , further comprising:

a stretchable base material on which flexible layer is provided.

9. The flexible substrate of claim 8 , wherein orthogonal projections of the notches in the flexible layer on the stretchable base material are located on solid part of the stretchable base material.

10. The flexible substrate of claim 1 , wherein the flexible layer comprises:

a plurality of functional element regions in which functional elements are arranged; and

non-functional element regions between adjacent functional element regions, the notches being arranged in the non-functional element regions.

11. A flexible display apparatus, comprising: the flexible substrate of claim 1 .

12. A method for producing a flexible substrate, the method comprising:

forming a flexible layer on a base plate;

forming notches in the flexible layer; and

transferring the flexible layer formed with the notches from the base plate to a stretchable base material to form the flexible substrate;

wherein before forming the notches in the flexible layer, the method further comprises: performing a first drying process on the flexible layer;

wherein after forming the notches in the flexible layer, the method further comprises: performing a second drying process on the flexible layer;

wherein before performing the second drying process, the method further comprises:

forming a filling layer on the flexible layer formed with the notches, wherein a first material forming the flexible layer and a second material forming the filling layer are configured such that there is a weak adhesion interface between the flexible layer and the filling layer;

etching and ashing the filling layer to expose the flexible layer while maintaining part of the filling layer filled in the notches; and

forming a buffer layer on the exposed flexible layer.

13. The method of claim 12 , wherein the forming notches in the flexible layer comprises forming notches, having depths less than or equal to thickness of the flexible layer, in the flexible layer.

14. The method of claim 12 , wherein the second drying process further comprises curing the flexible layer.

15. The method of claim 12 , further comprising:

stretching the stretchable substrate with the flexible layer adhered thereon such that the notches expand and deform until the flexible layer cracks along the notches.

16. The method of claim 12 , wherein 10% to 80% of a solvent in the flexible layer is removed in the first drying process; and

wherein more than 90% of the solvent in the flexible layer is removed in the second drying process.