Display substrate, display apparatus, and method of fabricating display substrate

1. A display substrate having a display area and a peripheral area, wherein the display substrate in the peripheral area comprises:

a flexible base substrate;

a first insulating layer on the flexible base substrate;

a first signal line layer comprising a plurality of first signal lines on a side of the first insulating layer away from the flexible base substrate;

a second insulating layer on a side of the first signal line layer away from the flexible base substrate;

a second signal line layer comprising a plurality of second signal lines on a side of the second insulating layer away from the first insulating layer; and

a third insulating layer on a side of the second signal line layer away from the flexible base substrate;

wherein the display substrate has a plurality of first vias extending through a respective one of the plurality of first signal lines, exposing a first surface of the first insulating layer;

the display substrate has a plurality of second vias extending through a respective one of the plurality of second signal lines, exposing a second surface of the second insulating layer;

the second insulating layer extends through the plurality of first vias to be in direct contact with the first surface of the first insulating layer; and

the third insulating layer extends through the plurality of second vias to be in direct contact with the second surface of the second insulating layer.

2. The display substrate of claim 1 ,

wherein an orthographic projection of the respective one of the plurality of first signal lines on the flexible base substrate is substantially non-overlapping with orthographic projections of the plurality of second signal lines on the flexible base substrate; and

an orthographic projection of the respective one of the plurality of second signal lines on the flexible base substrate is substantially non-overlapping with orthographic projections of the plurality of first signal lines on the flexible base substrate.

3. The display substrate of claim 2 , wherein orthographic projections of the plurality of first signal lines on the flexible base substrate and orthographic projections of the plurality of second signal lines on the flexible base substrate are alternately arranged.

4. The display substrate of claim 1 ,

wherein the plurality of first signal lines and the plurality of second signal lines extend along a direction from the display area to the peripheral area.

5. The display substrate of claim 1 ,

wherein the respective one of the plurality of first signal lines and the respective one of the plurality of second signal lines have a curved configuration in plan view of the display substrate.

6. The display substrate of claim 5 , wherein the curved configuration is an undulation configuration.

7. The display substrate of claim 1 ,

wherein a first width of the respective one of the plurality of first signal lines along a cross-section perpendicular to an extension direction of the respective one of the plurality of first signal lines is substantially uniform; and

a second width of the respective one of the plurality of second signal lines along a cross-section perpendicular to an extension direction of the respective one of the plurality of second signal lines is substantially uniform.

8. The display substrate of claim 1 ,

wherein a center point of a respective one of the plurality of first vias extending through the respective one of the plurality of first signal lines is substantially equidistant with respect to two opposite edges of the respective one of the plurality of first signal lines across a width of the respective one of the plurality of first signal lines; and

a center point of a respective one of the plurality of second vias extending through the respective one of the plurality of second signal lines is substantially equidistant with respect to two opposite edges of the respective one of the plurality of second signal lines across a width of the respective one of the plurality of second signal lines.

9. The display substrate of claim 1 ,

wherein a respective one of the plurality of first vias has a first diameter on a side away from the flexible base substrate and a second diameter on a side closer to the flexible base substrate, the first diameter being greater than the second diameter; and

a respective one of the plurality of second vias has a third diameter on a side away from the flexible base substrate and a fourth diameter on a side closer to the flexible base substrate, the third diameter being greater than the fourth diameter.

10. The display substrate of claim 9 , wherein the respective one of the plurality of first vias has a truncated cone shape, and the respective one of the plurality of second vias has a truncated cone shape.

11. The display substrate of claim 10 , wherein a first included angle between a lateral side of the respective one of the plurality of first vias and the flexible base substrate is in a range of 15 degrees to 85 degrees; and

a second included angle between a lateral side of the respective one of the plurality of second vias and the flexible base substrate is in a range of 15 degrees to 85 degrees.

12. The display substrate of claim 1 ,

wherein a first portion of the second insulating layer extending into a respective one of the plurality of first vias has a first diameter on a side away from the flexible base substrate and a second diameter on a side closer to the flexible base substrate, the first diameter being greater than the second diameter; and

a second portion of the third insulating layer extending into a respective one of the plurality of second vias has a third diameter on a side away from the flexible base substrate and a fourth diameter on a side closer to the flexible base substrate, the third diameter being greater than the fourth diameter.

13. The display substrate of claim 1 ,

wherein a first portion of the second insulating layer extending into a respective one of the plurality of first vias is in direct contact with the respective one of the plurality of first signal lines along a lateral side of the respective one of the plurality of first vias; and

a second portion of the third insulating layer extending into a respective one of the plurality of second vias is in direct contact with the respective one of the plurality of second signal lines along a lateral side of the respective one of the plurality of second vias.

14. The display substrate of claim 1 , further comprising a plurality of thin film transistors in the display area for driving image display of the display substrate;

wherein the peripheral area comprises a fan-out area;

at least a portion of the peripheral area being a bendable area; and

the bendable area is within the fan-out area.

15. The display substrate of claim 14 , wherein the fan-out area is between the display area and a bonding area for bonding a connection terminal.

16. The display substrate of claim 1 , wherein at least a portion of the peripheral area being a bendable area; and

the display substrate in the bendable area comprises:

the flexible base substrate;

the first insulating layer on the flexible base substrate;

the first signal line layer comprising the plurality of first signal lines on a side of the first insulating layer away from the flexible base substrate; and

the second insulating layer on a side of the first signal line layer away from the flexible base substrate;

wherein the display substrate has a plurality of first vias extending through a respective one of the plurality of first signal lines, exposing a first surface of the first insulating layer; and

the second insulating layer extends through the plurality of first vias to be in direct contact with the first surface of the first insulating layer.

17. A display apparatus, comprising the display substrate of claim 1 .

18. A method of fabricating a display substrate having a display area and a peripheral area, comprising, in the peripheral area:

forming a first insulating layer on a flexible base substrate;

forming a first signal line layer on a side of the first insulating layer away from the flexible base substrate, the first signal line layer formed to comprise a plurality of first signal lines;

forming a plurality of first vias extending through a respective one of the plurality of first signal lines, exposing a first surface of the first insulating layer;

forming a second insulating layer on a side of the first signal line layer away from the flexible base substrate, the second insulating layer formed to extend through the plurality of first vias to be in direct contact with the first surface of the first insulating layer forming a second signal line layer on a side of the second insulating layer away from the first insulating layer, the second signal line layer formed to comprise a plurality of second signal lines;

forming a plurality of second vias extending through a respective one of the plurality of second signal lines, exposing a second surface of the second insulating layer; and

forming a third insulating layer on a side of the second signal line layer away from the flexible base substrate, the third insulating layer formed to extend through the plurality of second vias to be in direct contact with the second surface of the second insulating layer.