FIELD

The present disclosure relates to the field of display technology, and particularly, to flexible display panels, manufacturing methods thereof and flexible display apparatuses.

BACKGROUND

A display apparatus is an apparatus for displaying a screen of characters, numbers, symbols and pictures, or an image formed by the combination of at least two of characters, numbers, symbols and pictures. The display apparatus may be a flat display apparatus, a curved display apparatus, a 3D display apparatus, a near-eye display apparatus, an AR/VR display apparatus, etc.

At present, with the rapid development of technology, flexible display apparatuses have gradually entered people's field of vision and are sought after by people. For example, there is a flexible display apparatus in the prior art, including a flexible display panel, where the flexible display panel includes a display area and a non-display area located around the display area. And in order to increase the screen-to-body ratio of the flexible display apparatus, certain non-display areas will be used as the bending area, and the bending area will be bent to the back of the flexible display panel, such as the area where a driver chip is located. In the bending area, there may be a lot of wires configured to transmit signals for achieving display function, touch function and other functions of the flexible display apparatus.

In the existing flexible display panel, when the bending area is bent, the wires in the bending area will also be bent, and thus the wires are easy to crack or even break, resulting in poor electrical conductivity.

SUMMARY

In view of the above problems, the embodiments of the present disclosure provide flexible display panels, manufacturing methods thereof and flexible display apparatuses, so as to solve the technical problem that the wires in the bending area are likely to crack or even break when the bending area in the flexible display panel is bent and thus the conductive function of the wires is adversely affected.

In order to achieve the above objective, the embodiments of the present disclosure provide the following technical solutions:

A first aspect of embodiments of the present disclosure provides a flexible display panel, including a display area and a bending area located around the display area, where the bending area includes: a flexible substrate; an adjustment layer, covering the entire flexible substrate; a protective layer, located on the adjustment layer; a plurality of wires, located on the protective layer; and a planarization layer, located above the wires and covering a functional film layer on the flexible substrate; where the protective layer corresponds to the wires in the bending area, and an orthographic projection of the wires in the bending area on the flexible substrate falls into an orthographic projection of the protective layer on the flexible substrate; when the bending area is bent, a bending stress is released through an interface between the adjustment layer and the protective layer, so as to relieve the stress that the protective layer bears when the bending area is bent.

In the bending area of the flexible display panel provided by the embodiment of the present disclosure, an adjustment layer is provided on the flexible substrate, and a protective layer is provided under the wires. An interface is formed between the protective layer and the adjustment layer, where the bending stress can be released through the interface to relieve the stress that the protective layer bears when the bending area is bent, thereby reducing the occurrence of cracks or even breaks in the wires in the bending area to prevent the conductive function of the wires from being adversely affected; at the same time, since the interface between the protective layer and the adjustment layer is formed, the bending stress can be released through the interface when the bending area is bent, and thus the adjustment layer and the protective layer can be provided with a smaller thickness within the range that can be achieved by the process. Therefore, when the bending area is being bent, stress concentration is not easily formed and the stress in the adjustment layer and the protective layer is easier to be released, which can reduce the occurrence of cracks or even breaks in the wires in the bending area to prevent the conductive function of the wires from being adversely affected. Moreover, in the flexible display panel provided by the embodiment of the present disclosure, the protective layer corresponds to the wires in the bending area, and an orthographic projection of the wires on the flexible substrate in the bending area falls into an orthographic projection of the protective layer on the flexible substrate. Compared with the usually used structure with a large coverage area of the functional film layer under the wires, when the bending area is being bent, stress concentration is not easily formed in the protective layer, and the stress in the protective layer is easily released, thereby further reducing the occurrence of cracks or even breaks in the wires to prevent the conductive function of the wires from being adversely affected.

In an embodiment of the present disclosure, an orthographic projection of the protective layer on the flexible substrate coincides with an orthographic projection of the wires in the bending area on the flexible substrate, and thus the coverage area of the protective layer under the wires is reduced. And when the bending area is being bent, stress concentration is not easily formed in the protective layer, and the stress in the protective layer is easily released, thereby further reducing the occurrence of cracks or even breaks in the wires to prevent the conductive function of the wires from being adversely affected.

In an embodiment of the present disclosure, there is no integral protective layer between adjacent wires in the bending area, thereby preventing stress from being conducted to each other, and thus further reducing the occurrence of cracks or even breaks in the wires to prevent the conductive function of the wires from being adversely affected.

In an embodiment of the present disclosure, a passivation layer is further provided between the wires and the planarization layer. When the bending area is bent, the stress that the passivation layer bears is equal to the stress that the protective layer bears. When the bending area is being bent, the passivation layer and the protective layer cooperate with each other to release the stress, and the stress that the passivation layer bears is equal to the stress that the protective layer bears at the same time. The wires are pulled by the passivation layer and the protective layer, and the upper and lower sides of the wires are evenly stressed, thereby further reducing the occurrence of cracks or even breaks in the wires to prevent the conductive function of the wires from being adversely affected.

In an embodiment of the present disclosure, the passivation layer covers the wires in the bending area and the adjustment layer. That is, after completing the deposition of the passivation film, the passivation film is directly used as the passivation layer, without further etching or other processes. In this way, the process steps of manufacturing the flexible display panel can be reduced, thereby increasing efficiency and lowering the cost.

In an embodiment of the present disclosure, the passivation layer is located on the wires in the bending area and corresponds to the wires in the bending area. That is, after completing the deposition of the passivation film, the passivation film is etched to form a passivation layer located on the wires in the bending area and corresponding to the wires in the bending area. And an orthographic projection of the passivation layer on the flexible substrate coincides with an orthographic projection of the wires in the bending area on the flexible substrate. In this way, the passivation layer does not cover sides of the wires in the bending area, and thus the probability of stress being transmitted from sides of the wires in the bending area to the wires in the bending area can be reduced and the probability of stress conduction between adjacent wires in the bending area can be reduced, thereby reducing the occurrence of cracks or even breaks in the wires to prevent the conductive function of the wires from being adversely affected.

In an embodiment of the present disclosure, the passivation layer is selected from the group consisting of a silicon oxide passivation layer, a silicon nitride passivation layer, a silicon oxynitride passivation layer and an organic material passivation layer.

In an embodiment of the present disclosure, the adjustment layer is an a-Si (amorphous silicon) layer. By selecting a-Si as the material of the adjustment layer, when the thin film transistor in the display area is a low temperature polysilicon thin film transistor, the adjustment layer and the active layer of the low temperature polysilicon thin film transistor can share a film layer structure, without the need to form an additional adjustment layer, thereby reducing the process steps of manufacturing a flexible display panel, increasing efficiency and lowering the cost. In addition, when forming the active layer, it is sufficient to directly perform doping on a-Si without etching, and thus the process steps of manufacturing the flexible display panel can be further reduced, thereby increasing efficiency and lowering the cost.

In an embodiment of the present disclosure, the thickness of the adjustment layer is less than or equal to 1000 Å, preferably less than or equal to 500 Å, so that the stress in the bending area is not easily concentrated.

In an embodiment of the present disclosure, the protective layer is a silicon oxide protective layer configured to prevent the hydrogen bond in the material of the protective film from adversely affecting the thin film transistor in the display area when depositing the protective film.

In an embodiment of the present disclosure, the thickness of the protective layer is less than or equal to 1000 Å, preferably 500 Å˜1000 Å. If the thickness of the protective layer is thicker, stress concentration may easily occur in the protective layer.

A second aspect of embodiments of the present disclosure provides a flexible display apparatus including the flexible display panel as described in the above technical solutions.

The flexible display apparatus has the same advantages as the above-mentioned flexible display panel over the prior art, and they will not be repeated herein.

A third aspect of embodiments of the present disclosure provides a method for manufacturing a flexible display panel, which includes: forming a flexible substrate; forming an adjustment layer on the flexible substrate, where the adjustment layer covers the entire flexible substrate; forming a protective layer on the adjustment layer; forming wires on the protective layer; and forming a planarization layer above the wires, where the planarization layer is located above wires in a bending area and covers a functional film layer on the flexible substrate; where the protective layer corresponds to the wires in the bending area of the flexible display panel, and an orthographic projection of the wires in the bending area on the flexible substrate falls into an orthographic projection of the protective layer on the flexible substrate.

The method for manufacturing a flexible display panel has the same advantages as the above-mentioned flexible display panel over the prior art, and they will not be repeated herein.

In an embodiment of the present disclosure, after forming the wires on the protective layer and before forming the planarization layer, the method for manufacturing the flexible display panel further includes: forming a passivation layer. When the bending area is being bent, the passivation layer and the protective layer cooperate with each other to release the stress. At the same time, when the bending area is being bent, the stress that the passivation layer bears is equal to the stress that the protective layer bears. The wires are pulled by the passivation layer and the protective layer, and the upper and lower sides of the wires are evenly stressed, thereby further reducing the occurrence of cracks or even breaks in the wires to prevent the conductive function of the wires from being adversely affected.

In an embodiment of the present disclosure, the steps of forming the protective layer, the wires and the passivation layer includes: forming a protective film; etching the protective film to form the protective layer corresponding to the wires in the bending area; preferably, the orthographic projection of the wires in the bending area on the flexible substrate coincides with the orthographic projection of the protective layer on the flexible substrate; forming the wires on the protective layer; and forming the passivation layer, where the passivation layer covers the wires in the bending area and the adjustment layer; or the steps of forming the protective layer, the wires and the passivation layer includes: forming a protective film; forming the wires on the protective film; forming a passivation film, where the passivation film covers the wires in the bending area and the protective film; and etching the passivation film and the protective film to form the protective layer corresponding to the wires in the bending area and the passivation layer corresponding to the wires in the bending area; preferably, the orthographic projections of the wires in the bending area, the protective layer and the passivation layer on the flexible substrate coincide with each other.

In addition, all the contents of the structure, functions and the like described for the flexible display panel in the first aspect of the present disclosure are also applicable to the method for manufacturing a flexible display panel in the third aspect of the present disclosure, and they will not be repeated herein.

In addition to the technical problems solved by the embodiments of the present disclosure described above, the technical features constituting the technical solutions, and the beneficial effects brought by the technical features of the technical solutions, the flexible display panel and the manufacturing method thereof provided by the embodiments of the present disclosure, other technical problems that can be solved by the flexible display apparatus, other technical features included in the technical solution, and beneficial effects brought by these technical features will be further detailed in the description of embodiments.

