Manufacturing method for flexible display panel and flexible display device

1. A method for manufacturing a flexible display panel, the method comprising:

forming an adhesion-variable back film on a non-light-exiting surface of a flexible display substrate, wherein the flexible display substrate comprises a plurality of flexible display sub-substrate, each of the flexible display sub-substrates comprising a display region, a bonding region, and a bending region between the display region and the bonding region, the bending region being a region to be bent of each of the flexible display sub-substrates;

cutting the adhesion-variable back film along a boundary of a to-be-removed region, wherein an orthogonal projection of the to-be-removed region on the flexible display substrate overlaps the bending region of each of at least two flexible display substrates of the plurality of flexible display sub-substrates;

removing the adhesion-variable back film in the to-be-removed region; and

increasing adhesion of the adhesion-variable back film to obtain the flexible display panel.

2. The method according to claim 1 , wherein

the adhesion-variable back film is made of a material, which has increased adhesion as being heated, and

increasing the adhesion of the adhesion-variable back film comprises: heating the adhesion-variable back film.

3. The method according to claim 1 , wherein

the adhesion-variable back film is made of a material, which has increased adhesion as being irradiated with particular light, and

increasing the adhesion of the adhesion-variable back film comprises: irradiating the adhesion-variable back film with the particular light.

4. The method according to claim 1 , wherein a width of an end portion of the to-be-removed region is greater than a width of a portion of the to-be-removed region whose orthogonal projection on the flexible display sub-substrate overlaps with the flexible display sub-substrate.

5. The method according to claim 1 , wherein

the adhesion-variable back film comprises a plurality of to-be-removed regions,

removing the adhesion-variable back film in the to-be-removed region comprises:

simultaneously removing the adhesion-variable back film in the to-be-removed regions.

6. The method according to claim 5 , wherein simultaneously removing the adhesion-variable back film in the to-be-removed regions comprises: adhering end portions, at a same side, of the adhesion-variable back film in the to-be-removed regions to a strip-shaped mechanical structure, and then simultaneously lifting up the end portions.

7. The method according to claim 1 , wherein after removing the adhesion-variable back film in the to-be-removed region and before increasing the adhesion of the adhesion-variable back film, the method further comprises:

adhering a lower protective film on a side of the adhesion-variable back film distal to the flexible display substrate.

8. The method according to claim 1 , further comprising forming an upper protective film on a light-exiting surface of the flexible display substrate.

9. The method according to claim 8 , wherein the upper protective film is beyond an edge of the flexible display substrate to be in contact with the adhesion-variable back film, and

adhesion between the adhesion-variable back film and the flexible display substrate is greater than adhesion between the adhesion-variable back film and the upper protective film.

10. A method for manufacturing a flexible display device, comprising:

manufacturing a flexible display panel according to the method of claim 1 ;

cutting the flexible display panel to obtain at least one flexible display sub-panel, each flexible display sub-panel comprising one flexible display sub-substrate and the adhesion-variable back film on the non-light-exiting surface of the flexible display sub-substrate; and

bending the flexible display sub-substrate in the bending region of the flexible display sub-substrate, such that the bonding region of the flexible display sub-substrate is adhered on a non-light-exiting side of the display region of the flexible display sub-substrate.

11. The method according to claim 10 , further comprising:

bonding a driving circuit in the bonding region of the flexible display sub-substrate; and

adhering an upper functional film to a light-exiting surface of the flexible display sub-substrate in the display region.

12. The method according to claim 11 , wherein

the upper functional film comprises at least one of a polarizer and a touch substrate.

13. The method according to claim 11 , wherein

an upper protective film is formed on the light-exiting surface of the flexible display sub-substrate; and

before adhering the upper functional film to the light-exiting surface of the flexible display sub-substrate in the display region, the method further comprises: removing the upper protective film.

14. The method according to claim 10 , wherein

a lower protective film is adhered on a side of the adhesion-variable back film distal to the flexible display sub-substrate, and

bending the flexible display sub-substrate in the bending region of the flexible display sub-substrate such that the bonding region of the flexible display sub-substrate is adhered on the non-light-exiting side of the display region of the flexible display sub-substrate comprises:

removing the lower protective film;

adhering a lower functional film on a side of the adhesion-variable back film distal to the flexible display sub-substrate, the lower functional film being in the display region of the flexible display sub-substrate and comprising a heat sink; and

bending the flexible display sub-substrate in the bending region of the flexible display sub-substrate, such that the bonding region of the flexible display sub-substrate is adhered onto the lower functional film.