Flexible display module and preparation method thereof, and display device

Abstract

The present disclosure provides a flexible display module and a preparation method and a display device, belonging to the field of display technology. The flexible display module includes a flexible display panel and a back film attached to the back of the flexible display panel; wherein the flexible display panel includes a main body portion, an adjacent portion, a binding bending portion, and a binding portion arranged in sequence. The back film includes a first back film portion attached to the main body portion, a second back film portion attached to the adjacent portion, and a third back film portion attached to the binding portion; the first back film portion, the second back film portion, and the third back film portion have the same thickness, and the elastic modulus of the first back film portion is less than the elastic modulus of the second back film portion and the elastic modulus of the third back film portion. The flexible display module can further improve performance.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a flexible display module and a preparation method thereof, and a display device. Background Art

[0002] Flexible display panels have the characteristics of flexibility and ultra-thinness, which enable the display device to achieve deformation. The backplane of the flexible display panel is very thin and needs to be attached with a back film for protection and support. At present, the back film of the flexible display panel is a uniform back film, and the material and thickness of the back film are the same at all positions. Then, the flexible display panel has different performance requirements for the back film in different areas; the uniform back film needs to compromise the performance requirements at different positions, which restricts the further improvement of the performance of the flexible display panel.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] The purpose of the present disclosure is to overcome the deficiencies of the above-mentioned prior art, provide a flexible display module and a preparation method thereof, and a display device, and further improve the performance of the flexible display module.

[0005] According to a first aspect of the present disclosure, a flexible display module is provided, comprising a flexible display panel and a back film attached to the back of the flexible display panel; wherein the flexible display panel comprises a main body portion, an adjacent portion, a binding bending portion, and a binding portion arranged in sequence;

[0006] The back film includes a first back film portion attached to the main body portion, a second back film portion attached to the adjacent portion, and a third back film portion attached to the binding portion;

[0007] The first back film portion, the second back film portion and the third back film portion have the same thickness, and the elastic modulus of the first back film portion is smaller than the elastic modulus of the second back film portion and the elastic modulus of the third back film portion.

[0008] According to an embodiment of the present disclosure, the elastic modulus of the first back film portion is between 1 and 5 GPa.

[0009] According to one embodiment of the present disclosure, the elastic modulus of the third back membrane portion is not less than 7 GPa.

[0010] According to one embodiment of the present disclosure, the thickness of the back film is between 25 and 60 microns.

[0011] According to an embodiment of the present disclosure, the elastic modulus of the third back film portion is between 7 and 12 GPa; and the thickness of the back film is between 45 and 55 microns.

[0012] According to an embodiment of the present disclosure, the material of the third back film portion is metal, and the thickness of the back film is between 25 and 35 microns.

[0013] According to an embodiment of the present disclosure, the back film is adhered to the back side of the flexible display panel through an adhesive layer.

[0014] According to a second aspect of the present disclosure, a method for preparing a flexible display module is provided, comprising:

[0015] Obtain a flexible display panel; the flexible display panel comprises a main body portion, an adjacent portion, a binding bending portion, and a binding portion arranged in sequence;

[0016] A back film is attached to the back of the flexible display panel; the back film includes a first back film portion attached to the main body portion, a second back film portion attached to the adjacent portion, and a third back film portion attached to the binding portion;

[0017] The first back film portion, the second back film portion and the third back film portion have the same thickness, and the elastic modulus of the first back film portion is smaller than the elastic modulus of the second back film portion and the elastic modulus of the third back film portion.

[0018] According to an embodiment of the present disclosure, attaching a back film to the back of the flexible display panel includes:

[0019] Obtain a back film material, the back film material comprising a release film and a back film located on one side of the release film, the back film package comprising a first back film portion for attaching to the main body portion, a second back film portion for attaching to the adjacent portion, and a third back film portion for attaching to the binding portion;

[0020] The back film of the back film material is attached to the back side of the flexible display panel, and then the release film is torn off.

[0021] According to an embodiment of the present disclosure, attaching a back film to the back of the flexible display panel includes:

[0022] Obtain a first back film material, a second back film material and a third back film material; the first back film material includes a first release film and a first back film portion located on one side of the first release film, the second back film material includes a second release film and a second back film portion located on one side of the second release film, and the third back film material includes a third release film and a third back film portion located on one side of the third release film;

[0023] The first back film portion is attached to the back side of the main body portion through the first back film material; the second back film portion is attached to the back side of the adjacent portion through the second back film material; and the third back film portion is attached to the back side of the binding portion through the third back film material.

[0024] According to an embodiment of the present disclosure, the first backing film material further includes a first filling layer, and the first filling layer and the first backing film portion are located on the same side of the first release film and are spliced ​​with each other and have the same thickness;

[0025] The second backing film material further includes a second filling layer, and the second filling layer and the second backing film portion are located on the same side of the second release film and are spliced ​​with each other and have the same thickness;

[0026] The third back film material further includes a third filling layer. The third filling layer and the third back film portion are located on the same side of the third release film and are spliced ​​with each other and have the same thickness.

[0027] According to an embodiment of the present disclosure, the first backing film material further includes a first adhesive layer located on a side of the first backing film portion away from the first release film; the thickness of the first filling layer is the same as the total thickness of the first backing film portion and the first adhesive layer;

[0028] The second backing film material further includes a second adhesive layer located on a side of the second backing film portion away from the second release film; the thickness of the second filling layer is the same as the total thickness of the second backing film portion and the second adhesive layer;

[0029] The third backing film material further includes a third adhesive layer located on a side of the third backing film portion away from the first release film; the thickness of the third filling layer is the same as the total thickness of the third backing film portion and the third adhesive layer.

[0030] According to a third aspect of the present disclosure, a display device is provided, comprising the above-mentioned flexible display module.

[0031] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0033] Figure 1The figure is a schematic diagram of a partial structure of a display device in the related art.

[0034] Figure 2 The present invention is a schematic diagram of the structure of a flexible display module in an unbent state in the related art.

[0035] Figure 3 The figure is a schematic diagram of a top view structure of a flexible display panel in one embodiment of the present disclosure.

[0036] Figure 4 This is a schematic diagram of the cross-sectional structure of a flexible display module when it is not bent in one embodiment of the present disclosure.

[0037] Figure 5 A schematic diagram of a local state of a binding bending portion of a flexible display module when it is bent in a display device provided in an embodiment of the present disclosure.

[0038] Figure 6 A schematic diagram of a partial cross-sectional structure of a flexible display panel is disclosed in one embodiment.

[0039] Figure 7 This is a schematic diagram of the cross-sectional structure of a flexible display module when it is not bent in one embodiment of the present disclosure.

[0040] Figure 8 The figure is a schematic flow chart of a method for preparing a flexible display module in one embodiment of the present disclosure.

[0041] Fig. 9 It is a schematic structural diagram of attaching a back film material to the back side of a flexible display panel in one embodiment of the present disclosure.

[0042] Fig.10 It is a schematic structural diagram of attaching a back film material to the back side of a flexible display panel in one embodiment of the present disclosure.

[0043] Fig.11 It is a schematic structural diagram of attaching a back film material to the back side of a flexible display panel in one embodiment of the present disclosure.

[0044] Fig.12 It is a schematic structural diagram of attaching a first backing film material to the back side of a flexible display panel in one embodiment of the present disclosure.

[0045] Fig.13 It is a schematic structural diagram of attaching a second backing film material to the back side of a flexible display panel in one embodiment of the present disclosure.

[0046] Fig.14 It is a schematic structural diagram of attaching a third back film material to the back side of a flexible display panel in one embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0048] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0049] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0050] A transistor is a component that includes at least three terminals: a gate, a drain, and a source. A transistor has a channel region between the drain and the source, and current can flow through the drain, the channel region, and the source. The channel region is a region where current mainly flows.

[0051] The structure layer A is located on the side of the structure layer B away from the substrate, which can be understood as the structure layer A being formed on the side of the structure layer B away from the substrate. When the structure layer B is a patterned structure, part of the structure layer A may also be located at the same physical height as the structure layer B or lower than the physical height of the structure layer B, wherein the substrate is a height reference.

[0052] Figure 1 The figure is a schematic diagram of a partial structure of a display device in the related art. Figure 2 FIG. 1 is a schematic diagram of a structure of a flexible display module in an unbent state in the related art. Figure 1 and Figure 2The flexible display module includes a flexible display panel PNL and a back film BF located on the back of the flexible display panel PNL. The flexible display panel PNL has a binding bending portion DD and a main body portion AA and a binding portion CC located on both sides of the binding bending portion DD. In the display device, the flexible display panel PNL is bent toward the back at the binding bending portion DD, so that the binding portion CC is bent to the back of the main body portion AA to reduce the frame of the display device. The back film BF provides support and protection for the flexible display panel PNL, which is hollowed out at the binding bending portion DD and uses the same material and thickness at other positions.

[0053] However, according to Figure 1 It can be seen that when the flexible display panel PNL is bent at the binding bending part DD, it will generate greater stress to the adjacent part BB and the binding part CC adjacent to the binding bending part DD; therefore, in theory, the adjacent part BB and the binding part CC adjacent to the binding bending part DD require the back film BF to provide stronger support, such as thicker thickness or higher elastic modulus. The main part AA needs to maintain flexible deformation ability, so the main part AA requires the back film BF to be more flexible, such as thinner thickness or smaller elastic modulus. In other words, when the back film BF maintains the same thickness, the back film BF should have a higher elastic modulus at the adjacent part BB and the binding part CC to meet the support requirements for the adjacent part BB and the binding part CC; the back film BF should have a smaller elastic modulus at the main part AA to improve the deformation performance and deformation reliability of the flexible display panel PNL at the main part AA. In the related art, it is generally necessary to compromise between the requirements of the adjacent part BB / binding part CC on the back film BF and the requirements of the main part AA on the back film BF; this compromise design makes it impossible to fully exert the performance of the flexible display panel PNL, restricting the further improvement of the performance of the display device.

[0054] The present disclosure provides a flexible display module and a method for preparing the flexible display module. Figure 3 to Figure 6 The flexible display module provided in the embodiment of the present disclosure includes a flexible display panel PNL and a back film BF attached to the back side (the side not used for emitting light) of the flexible display panel PNL. The flexible display panel PNL includes a main body portion AA, an adjacent portion BB, a binding bending portion DD, and a binding portion CC arranged in sequence. The back film BF includes a first back film portion BFA attached to the main body portion AA, a second back film portion BFB attached to the adjacent portion BB, and a third back film portion BFC attached to the binding portion CC. The first back film portion BFA, the second back film portion BFB, and the third back film portion BFC have the same thickness, and the elastic modulus of the first back film portion BFA is smaller than the elastic modulus of the second back film portion BFB and the elastic modulus of the third back film portion BFC.

[0055] In this way, the back of the flexible display panel PNL provided by the embodiment of the present disclosure does not have a uniform back film BF attached, and the elastic modulus of the back film of each part is configured according to the performance requirements of the back film BF of different parts of the flexible display panel PNL, so that the performance of the flexible display panel PNL can be more fully exerted. Specifically, in the main body part AA, the elastic modulus of the first back film part BFA is small, so that the main body part AA has better flexibility and better bending reliability, so that the main body part AA can be better bent while displaying. The second back film part BFB and the third back film part BFC are used to support and protect the adjacent part BB and the binding part CC. Therefore, the second back film part BFB and the third back film part BFC have a larger elastic modulus to ensure the support strength of the back film BF for the flexible display panel PNL, and avoid defects caused by insufficient support for the adjacent part BB and the binding part CC. In particular, it can be avoided that the third back film part BFC is insufficient to protect the binding part CC and cause defects during the binding process. In other words, in the flexible display module of the embodiment of the present disclosure, the performance characteristics of the back film BF in different areas can be specifically set according to the actual needs of the area, thereby reducing the constraints of the back film BF on the performance of the flexible display module, so that the characteristics of the flexible display panel PNL can be more fully utilized.

[0056] As follows, the structure, principle, effect and preparation method of the flexible display module provided by the embodiment of the present disclosure are further explained and illustrated in conjunction with the accompanying drawings.

[0057] Figure 3 FIG. 1 is a schematic diagram of a top view of the flexible display panel PNL in one embodiment of the present disclosure. Figure 4 This is a schematic diagram of the cross-sectional structure of a flexible display module when it is not bent in one embodiment of the present disclosure. Figure 5 It is a schematic diagram of a local state of a binding bending portion DD of a flexible display module when it is bent in a display device provided in an embodiment of the present disclosure. Figure 6 To disclose a partial cross-sectional structural schematic diagram of a flexible display panel PNL in one embodiment.

[0058] See also Figure 3, along the direction of a set straight line, the flexible display panel PNL includes a main part AA, an adjacent part BB, a binding bending part DD and a binding part CC arranged in sequence. Wherein, when the flexible display module is applied to a display device, the flexible display module can be bent at the binding bending part DD, so that the binding part CC is bent to the back of the adjacent part BB and the main part AA. In one example, the flexible display panel PNL is provided with a module protection film MCL covering the binding bending part DD on the front side (the light emitting side) to protect the wiring and the like arranged in the binding bending part DD and balance the stress of the binding bending part DD when it is bent, so that the stress and strain of the binding bending part DD when it is bent mainly acts on the module protection film MCL.

[0059] The main part AA may be provided with pixels and a driving circuit for driving the pixels. Of course, the whole or part of the adjacent part BB may also be provided with pixels and a driving circuit for driving the pixels, so that the whole or part of the adjacent part BB may also display images.

[0060] In the display device, the binding portion CC is used to bind the driving component DR for driving the flexible display panel PNL. In one example, the driving component may include a flexible circuit board bound and connected to the flexible display panel PNL. In another example, the driving component may include a chip-on-film (COF) bound and connected to the flexible display panel PNL, and a driving chip may be provided on the chip-on-film. Of course, the driving component may also be in other forms, such as a flexible circuit board bound and connected to the flexible display panel PNL, and a driving chip directly bound to the flexible display panel PNL. The embodiment of the present disclosure does not limit the composition and setting method of the driving component, and is based on the binding portion CC bound to the flexible display panel PNL and used to drive the flexible display panel PNL.

[0061] Optionally, when the flexible display module is applied to a display device, the display device can be provided with a bending support pad BS; when the flexible display module is bent, the second back film portion BFB and the third back film portion BFC are connected to both sides of the bending support pad BS so as to control and fix the bending radius of the flexible display panel PNL in the binding bending portion DD, thereby improving the reliability of the display device.

[0062] See also Figure 6 The flexible display panel PNL may include a base substrate F100, a driving circuit layer F200 and a pixel layer F300 which are stacked in sequence. The pixel layer is provided with sub-pixels for display, and the driving circuit layer is provided with a pixel driving circuit for driving each sub-pixel to emit light.

[0063] The substrate F100 may be a flexible substrate, and its material may be an organic material that is easy to bend or a composite structure of an organic material and an inorganic material. For example, in one embodiment of the present disclosure, the material of the substrate F100 may be polyimide (PI). For another example, the material of the substrate F100 may include multiple layers of polyimide, with silicon oxide, silicon nitride or other inorganic materials sandwiched between the polyimide layers. It is understood that in other embodiments of the present disclosure, the substrate may also be made of other materials, so that the substrate is a flexible substrate.

[0064] The driving circuit layer F200 is provided with a pixel driving circuit for driving sub-pixels. In the driving circuit layer F200, any pixel driving circuit may include a transistor F200M and a storage capacitor. Further, the transistor F200M may be a thin film transistor, and the thin film transistor may be selected from a top-gate thin film transistor, a bottom-gate thin film transistor or a double-gate thin film transistor; the material of the active layer of the thin film transistor may be an amorphous silicon semiconductor material, a low-temperature polycrystalline silicon semiconductor material, a metal oxide semiconductor material, an organic semiconductor material or other types of semiconductor materials; the thin film transistor may be an N-type thin film transistor or a P-type thin film transistor.

[0065] It is understandable that, among the transistors in the pixel driving circuit, the types of any two transistors may be the same or different. Exemplarily, in one embodiment, in a pixel driving circuit, some transistors may be N-type transistors and some transistors may be P-type transistors. Again exemplarily, in another embodiment of the present disclosure, in a pixel driving circuit, the material of the active layer of some transistors may be a low-temperature polysilicon semiconductor material, and the material of the active layer of some transistors may be a metal oxide semiconductor material. In some embodiments of the present disclosure, the thin film transistor is a low-temperature polysilicon transistor. In some other embodiments of the present disclosure, some thin film transistors are low-temperature polysilicon transistors, and some thin film transistors are metal oxide transistors.

[0066] Optionally, the driving circuit layer F200 may include a semiconductor layer F203, a gate insulating layer F204, a gate layer F205, an interlayer dielectric layer F206, and a source-drain metal layer F207 stacked between the substrate F100 and the pixel layer F300. Each thin film transistor and storage capacitor may be formed by a semiconductor layer F203, a gate insulating layer F204, a gate layer F205, an interlayer dielectric layer F206, a source-drain metal layer F207, and other film layers. Among them, the positional relationship of each film layer may be determined according to the film layer structure of the thin film transistor. Further, the semiconductor layer F203 may be used to form the channel region of the transistor; the gate layer may be used to form gate layer wiring such as scanning leads, reset control leads, and light-emitting control leads, and may also be used to form the gate of the transistor, and may also be used to form part or all of the electrode plates of the storage capacitor; the source-drain metal layer may be used to form source-drain metal layer wiring such as data leads and driving power leads, and may also be used to form part of the electrode plates of the storage capacitor. In the present disclosure, the overall extension direction of the data lead can be defined as the column direction of the display module, and the overall extension direction of the scan lead can be defined as the row direction of the display module. In an example, along the column direction of the flexible display panel PNL, the flexible display panel PNL includes a main body portion AA, an adjacent portion BB, a binding bent portion DD, and a binding portion CC that are sequentially arranged.

[0067] For example, in some embodiments of the present disclosure, the driving circuit layer F200 may include a semiconductor layer F203, a gate insulating layer F204, a gate layer F205, an interlayer dielectric layer F206 and a source-drain metal layer F207 stacked in sequence, and the thin film transistor formed in this way is a top-gate thin film transistor.

[0068] To give another example, in some embodiments of the present disclosure, the driving circuit layer F200 may include a gate layer F205, a gate insulating layer F204, a semiconductor layer F203, an interlayer dielectric layer F206 and a source-drain metal layer F207 stacked in sequence, and the thin film transistor formed in this way is a bottom-gate thin film transistor.

[0069] In some embodiments, the gate layer may be two or three layers. For example, in one embodiment of the present disclosure, the gate layer F205 may include a first gate layer and a second gate layer, and the gate insulating layer F204 may include a first gate insulating layer for isolating the semiconductor layer F203 and the first gate layer, and a second gate insulating layer for isolating the first gate layer and the second gate layer. Exemplarily, the driving circuit layer F200 may include a semiconductor layer F203, a first gate insulating layer, a first gate layer, a second gate insulating layer, a second gate layer, an interlayer dielectric layer F206, and a source-drain metal layer F207 stacked sequentially on one side of the substrate F100. For another example, in one embodiment of the present disclosure, the gate layer F205 may include a first gate layer and a second gate layer, and the semiconductor layer F203 may be sandwiched between the first gate layer and the second gate layer; the gate insulating layer F204 may include a first gate insulating layer for isolating the semiconductor layer F203 and the first gate layer, and a second gate insulating layer for isolating the second gate layer and the semiconductor layer F203. For example, in one embodiment of the present disclosure, the driving circuit layer F200 may include a first gate layer, a first gate insulating layer, a semiconductor layer F203, a second gate insulating layer, a second gate layer, an interlayer dielectric layer F206, and a source-drain metal layer F207 stacked in sequence on one side of the substrate F100. In this way, a transistor with a dual-gate structure may be formed. For another example, in one embodiment of the present disclosure, the semiconductor layer F203 may include a low-temperature polycrystalline silicon semiconductor layer and a metal oxide semiconductor layer; the gate layer includes a first gate layer and a second gate layer, and the gate insulating layer includes a first and a second gate insulating layer. The driving circuit layer F200 may include a low-temperature polycrystalline silicon semiconductor layer, a first gate insulating layer, a first gate layer, a metal oxide semiconductor layer, a second gate insulating layer, a second gate layer, an interlayer dielectric layer F206, and a source-drain metal layer F207 stacked in sequence on one side of the substrate F100. For another example, in one embodiment of the present disclosure, the semiconductor layer F203 may include a low-temperature polysilicon semiconductor layer and a metal oxide semiconductor layer; the gate layer includes first to third gate layers, and the gate insulating layer includes first to third gate insulating layers. The driving circuit layer F200 may include a low-temperature polysilicon semiconductor layer, a first gate insulating layer, a first gate layer, an insulating buffer layer, a second gate layer, a second gate insulating layer, a metal oxide semiconductor layer, a third gate insulating layer, a third gate layer, an interlayer dielectric layer F206, and a source-drain metal layer F207, which are sequentially stacked on one side of the base substrate F100.

[0070] In some embodiments, the source-drain metal layer may be two or three layers. For example, in one embodiment of the present disclosure, the source-drain metal layer may include a first source-drain metal layer and a second source-drain metal layer sequentially stacked on the side of the interlayer dielectric layer F206 away from the substrate substrate, and an insulating layer may be sandwiched between the first source-drain metal layer and the second source-drain metal layer, for example, a passivation layer and / or a planarization layer. For another example, in one embodiment of the present disclosure, the source-drain metal layer may include a first source-drain metal layer, a second source-drain metal layer, and a third source-drain metal layer sequentially stacked on the side of the interlayer dielectric layer F206 away from the substrate substrate; an insulating layer may be sandwiched between the first source-drain metal layer and the second source-drain metal layer, for example, a passivation layer and / or a resin layer; an insulating layer may be sandwiched between the second source-drain metal layer and the third source-drain metal layer, for example, a passivation layer and / or a planarization layer.

[0071] Optionally, the driving circuit layer F200 may further include a passivation layer. The passivation layer may be disposed on a surface of the source-drain metal layer F207 away from the base substrate F100 so as to protect the source-drain metal layer F207.

[0072] Optionally, the driving circuit layer F200 may further include a buffer material layer F201 disposed between the base substrate F100 and the semiconductor layer F203, and the semiconductor layer F203, the gate layer F205, etc. are all located on the side of the buffer material layer away from the base substrate F100. The material of the buffer material layer may be an inorganic insulating material such as silicon oxide, silicon nitride, etc. The buffer material layer may be a single inorganic material layer or a multi-layered inorganic material layer.

[0073] Optionally, the driving circuit layer F200 may further include a planarization layer F208 located between the source-drain metal layer F207 and the pixel layer F300, and the planarization layer F208 may provide a planarized surface for the pixel electrode. Optionally, the material of the planarization layer F208 may be an organic material.

[0074] Optionally, the pixel layer is provided with a light-emitting element as a sub-pixel, and each light-emitting element emits light under the control of a pixel driving circuit. In the present disclosure, the light-emitting element may be an organic light-emitting diode (OLED), a micro light-emitting diode (Micro LED), a mini light-emitting diode (Mini LED), a quantum dot-organic light-emitting diode (QD-OLED), a quantum dot light-emitting diode (QLED) or other types of light-emitting elements. Exemplarily, in one embodiment of the present disclosure, the light-emitting element is an organic light-emitting diode (OLED), and the display panel is an OLED display panel. As follows, taking the light-emitting element as an organic light-emitting diode as an example, an exemplary introduction to a feasible structure of the pixel layer is given.

[0075] Optionally, the pixel layer F300 may be arranged on a side of the driving circuit layer F200 away from the base substrate F100, and may include a pixel electrode layer F301, a pixel definition layer F302, a support column layer F303, an organic light-emitting functional layer F304 and a common electrode layer F305 stacked in sequence. Among them, the pixel electrode layer F301 has a plurality of pixel electrodes in the display area of ​​the display panel; the pixel definition layer F302 has a plurality of through pixel openings arranged one-to-one corresponding to the plurality of pixel electrodes in the display area, and any pixel opening exposes at least a portion of the corresponding pixel electrode. The support column layer F303 includes a plurality of support columns in the display area, and the support columns are located on the surface of the pixel definition layer F302 away from the base substrate F100, so as to support the fine metal mask during the evaporation process. The organic light-emitting functional layer F304 at least covers the pixel electrodes exposed by the pixel definition layer F302. Among them, the organic light-emitting functional layer F304 may include an organic electroluminescent material layer, and may include one or more of a hole injection layer, a hole transport layer, an electron blocking layer, a hole blocking layer, an electron transport layer and an electron injection layer. The various film layers of the organic light-emitting functional layer F304 can be prepared by an evaporation process, and a fine metal mask or an open mask (Open Mask) can be used to define the pattern of each film layer during evaporation. The common electrode layer F305 can cover the organic light-emitting functional layer F304 in the display area. In this way, the pixel electrode, the common electrode layer F305 and the organic light-emitting functional layer F304 located between the pixel electrode and the common electrode layer F305 form an organic electroluminescent diode F300D, and any organic electroluminescent diode can be used as a sub-pixel of the display panel.

[0076] In some embodiments, the pixel layer F300 may further include a light extraction layer located on a side of the common electrode layer F305 away from the base substrate F100 to enhance the light extraction efficiency of the organic light emitting diode.

[0077] Optionally, the display panel may further include a thin film encapsulation layer F400. The thin film encapsulation layer F400 is disposed on the surface of the pixel layer F300 away from the base substrate F100, and may include an inorganic encapsulation layer and an organic encapsulation layer alternately stacked. Among them, the inorganic encapsulation layer can effectively block external moisture and oxygen, and prevent water and oxygen from invading the organic light-emitting functional layer F304 and causing material degradation. Optionally, the edge of the inorganic encapsulation layer may be located in the peripheral area. The organic encapsulation layer is located between two adjacent inorganic encapsulation layers to achieve flattening and reduce the stress between the inorganic encapsulation layers. Among them, the edge of the organic encapsulation layer may be located between the edge of the display area and the edge of the inorganic encapsulation layer. Exemplarily, the thin film encapsulation layer F400 includes a first inorganic encapsulation layer F401, an organic encapsulation layer F402, and a second inorganic encapsulation layer F403 sequentially stacked on the side of the pixel layer F300 away from the base substrate F100.

[0078] Optionally, the display panel may further include a touch function layer F500 , which is disposed on a side of the thin film encapsulation layer F400 away from the base substrate F100 , and is used to implement a touch operation of the display panel.

[0079] It can be understood that the above-mentioned example of the flexible display panel PNL is merely an example of an OLED flexible display panel; the flexible display panel PNL of the embodiment of the present disclosure is not limited to the above-mentioned example, for example, it can be a flexible OLED display panel of other structures, or it can be a flexible display panel using other light-emitting elements.

[0080] In one embodiment of the present disclosure, see Figure 4 The flexible display module may further include a reflection reducing layer POL located on the side of the flexible display panel PNL away from the back film BF, so as to reduce the reflection of the flexible display panel PNL to the ambient light and improve the contrast of the flexible display module. Optionally, the reflection reducing layer POL may be a polarizer or a color filter.

[0081] In an example, the reflection reducing layer POL covers the main portion AA and at least a portion of the adjacent portion BB to ensure that the area for display is fully covered.

[0082] In one embodiment of the present disclosure, the back film BF has a uniform thickness, and the thickness is between 25 microns and 60 microns. If the thickness of the back film BF is further increased, the reliability of the flexible display panel PNL in the main part AA will be insufficient; if the thickness of the back film BF is further reduced, the binding bending part DD of the flexible display panel PNL will be prone to failure when binding the driving component DR. In some examples of the present disclosure, the thickness of the back film BF is between 25 and 35 microns. In other examples, the thickness of the back film BF is between 45 and 55 microns.

[0083] In one embodiment of the present disclosure, the elastic modulus of the first back film part BFA is between 1 and 5 GPa, for example, 1.0 GPa, 2.0 GPa, 3.5 GPa, 4 GPa, 5 GPa, etc. The optional material of the first back film part BFA can be a polymer, for example, the main material of the first back film part BFA can be polyimide.

[0084] In one example, the elastic modulus of the first back film portion BFA is between 2 and 4 GPa, and the thickness of the back film BF is between 25 and 35 microns. Exemplarily, the elastic modulus of the first back film portion BFA is 3 GPa, and the thickness is 30 microns. In this way, the first back film portion BFA has a smaller thickness and a reduced elastic modulus, which allows the bending performance of the flexible display module in the main body portion AA to be more fully exerted and has better bending reliability.

[0085] In one embodiment of the present disclosure, the elastic modulus of the third back film portion BFC is not less than 7 GPa, and in particular, may be not less than 10 GPa. For example, the material of the third back film portion BFC may be a polymer with a high elastic modulus, or a metal with a high elastic modulus. Furthermore, when the elastic modulus of the material selected for the third back film portion BFC exceeds 30 GPa, the thickness of the back film BF may be appropriately reduced to improve the reliability of the flexible display module in the main body portion AA.

[0086] In one example, the elastic modulus of the third back film portion BFC is between 7 and 12 GPa, and the thickness of the back film BF is between 45 and 55 microns. For example, the elastic modulus of the third back film portion BFC is 10 to 11 GPa, the material selected is an organic polymer, and the thickness of the back film BF is 50 microns.

[0087] In another example, the material of the third back film BFC is metal, and the thickness of the back film BF is between 25 and 35 microns. Optionally, the material of the third back film BFC can be stainless steel, titanium alloy or aluminum alloy. For example, the material of the third back film BFC is stainless steel with a thickness of 30 microns. In this way, the back film can achieve a better balance between maintaining the flexibility and reliability of the main part and maintaining support for the binding part. The thicker the back film, the greater the strain of the key film layer when the main part is deformed; for example, when the back film is 13 microns, the strain of the pixel layer of the flexible display panel when it is bent can be about -1%, the strain of the thin film encapsulation layer is about 1%, and the strain of the source and drain metal layer is about 1.2%. When the thickness of the back film is increased to 50 microns, the strain of the pixel layer is about -1.8%, the strain of the thin film encapsulation layer is about 1.2%, and the strain of the source and drain metal layer is about 2%. Therefore, reducing the thickness of the back film helps to reduce the strain of the flexible display panel when it is bent, thereby improving the reliability of the flexible display panel. However, the reduction in the thickness of the back film will cause poor binding in the binding area, so the back film needs to maintain a certain thickness. In this example, the third back film part BFC has a high elastic modulus by using metal as the material, which allows the thickness of the third back film part BFC to be reduced to between 25 and 35 microns, thereby reducing the overall thickness of the back film and improving the reliability of the flexible display module without reducing the binding yield.

[0088] The material of the second back membrane portion BFB may be the same as or different from that of the third back membrane portion BFC, provided that the elastic modulus thereof is greater than the elastic modulus of the first back membrane portion BFA. In one embodiment of the present disclosure, the elastic modulus of the second back membrane portion BFB may be 0.8 to 1.2 times the elastic modulus of the third back membrane portion BFC. In one example, the second back membrane portion BFB and the third back membrane portion BFC are made of the same material.

[0089] In one embodiment of the present disclosure, see Figure 7 , the back film BF can also be bonded to the back side (base substrate) of the flexible display panel PNL through the adhesive layer OC. For example, the adhesive layer OC includes a first adhesive layer OCA located on the upper surface of the first back film portion BFA (the surface close to the flexible display panel PNL), a second adhesive layer OCB located on the upper surface of the second back film portion BFB (the surface close to the flexible display panel PNL), and a third adhesive layer OCC located on the upper surface of the third back film portion BFC (the surface close to the flexible display panel PNL). The first back film portion BFA is bonded to the back side (base substrate of the flexible display panel PNL) of the flexible display panel PNL through the first adhesive layer OCA, the second back film portion BFB is bonded to the back side (base substrate of the flexible display panel PNL) of the flexible display panel PNL through the second adhesive layer OCB, and the third back film portion BFC is bonded to the back side (base substrate of the flexible display panel PNL) of the flexible display panel PNL through the third adhesive layer OCC.

[0090] In one embodiment of the present disclosure, the thickness of the adhesive layer OC is less than the thickness of the back film BF, for example, it can be 10 to 15 microns. In one example, the thickness of the adhesive layer OC is 13 microns. In this way, the strain of the key film layer of the flexible display panel PNL can be smaller, which is conducive to improving the reliability of the flexible display panel PNL.

[0091] The present disclosure also provides a method for preparing the flexible display module. Figure 8 , the preparation method of the flexible display module comprises:

[0092] Step S110, obtaining a flexible display panel PNL; the flexible display panel PNL includes a main body portion AA, an adjacent portion BB, a binding bending portion DD, and a binding portion CC arranged in sequence;

[0093] Step S120, attaching a back film BF to the back side of the flexible display panel PNL; the back film BF includes a first back film portion BFA attached to the main portion AA, a second back film portion BFB attached to the adjacent portion BB, and a third back film portion BFC attached to the binding portion CC; wherein the first back film portion BFA, the second back film portion BFB and the third back film portion BFC have the same thickness, and the elastic modulus of the first back film portion BFA is smaller than the elastic modulus of the second back film portion BFB and the elastic modulus of the third back film portion BFC.

[0094] Thus, according to the preparation method, the flexible display module provided in the above embodiment can be prepared, so that the flexible display module has better flexibility and better reliability in the main part AA, and the flexible display panel PNL obtains better support and binding yield in the adjacent part BB and the binding part CC.

[0095] In some embodiments of the present disclosure, a one-step material strategy can be adopted to attach a back film BF to the back of the flexible display panel PNL. For example, a back film material BFM with a spliced ​​back film can be first obtained, and the back film material BFM includes a release film RF and a film material to be attached on the same side of the release film RF. Then, the film material to be attached is attached to the back of the flexible display panel PNL, and then the release film RF is torn off. Among them, the film material to be attached can be a back film BF, or it can be a back film BF and an adhesive layer OC arranged on the surface of the back film BF away from the release film RF. It can be understood that in some examples, the back film material BFM can also include a protective layer located on the side of the film material to be attached away from the release film RF; before attaching the film material to be attached to the back of the flexible display panel PNL, the protective layer can be torn off to expose the film material to be attached.

[0096] In one embodiment of the present disclosure, see Fig. 9 , a back film material BFM can be obtained first, the back film material BFM includes a release film RF and a back film BF located on one side of the release film RF, the back film BF includes a first back film portion BFA for attaching to the main part AA, a second back film portion BFB for attaching to the adjacent part BB, and a third back film portion BFC for attaching to the binding part CC. Then, the back film BF of the back film material BFM is attached to the back of the flexible display panel PNL, and then the release film RF is torn off. In this way, the back film BF is attached to the back of the flexible display panel PNL. In this strategy, a back film material BFM with a spliced ​​back film BF (a first back film portion BFA, a second back film portion BFB, and a third back film portion BFC) can be prepared first, and then the attachment of the back film BF can be completed by one-step attachment, which has a higher attachment efficiency and a higher attachment accuracy. In this example, the film material to be attached is a back film BF.

[0097] In another embodiment of the present disclosure, see Fig.10, the back film material BFM may also include an adhesive layer OC located on the upper surface of the back film BF (the surface close to the flexible display panel PNL, that is, the surface away from the release film RF). For example, the upper surface of the first back film part BFA is provided with a first adhesive layer OCA, the upper surface of the second back film part BFB is provided with a second adhesive layer OCB, and the upper surface of the third back film part BFC is provided with a third adhesive layer OCC. When the back film material BFM is attached to the back of the flexible display panel PNL, the adhesive layer OC can be adhered to the back of the flexible display panel PNL (the surface of the base substrate of the flexible display panel PNL); when the release film RF is torn off, the attachment of the back film BF to the flexible display panel PNL can be completed, and the back film BF is adhered to the back of the flexible display panel PNL through the adhesive layer OC. In this example, the film materials to be attached are the back film BF and the adhesive layer OC located on the surface of the back film BF away from the release film RF.

[0098] In one embodiment of the present disclosure, see Fig.11 , the back film material BFM may also include a filling layer DUM corresponding to the binding bending portion DD of the flexible display panel PNL, and the filling layer DUM has the same thickness as the film material to be attached. Exemplarily, when the film material to be attached of the back film material BFM is the back film BF, the thickness of the filling layer DUM is the same as the thickness of the back film BF. Another exemplary embodiment, when the film material to be attached is a stacked back film BF and an adhesive layer OC, the thickness of the filling layer DUM is the same as the total thickness of the back film BF and the adhesive layer OC. In this way, the filling layer DUM can keep the back film material BFM intact, avoiding the risk of deformation of the back film material BFM due to the lack of the film material to be attached between the second back film portion BFB and the third back film portion BFC.

[0099] In one example, when the release film RF is torn off, the filling layer DUM remains connected to the release film RF, so that the filling layer DUM is torn off along with the release film RF.

[0100] In another example, when the release film RF is torn off, the filling layer DUM is not torn off along with the release film RF; after the release film RF is torn off, the filling layer DUM can be torn off separately.

[0101] In another example, the back film material BFM further includes a protective layer, which is located on the side of the film material to be attached away from the release film RF. When attaching the back film material BFM, the protective layer needs to be torn off first to expose the film material to be attached, and then the film material to be attached is attached to the back of the flexible display panel PNL. Furthermore, when the protective layer is torn off, the filling layer DUM can be torn off together.

[0102] In some other embodiments of the present disclosure, a step-by-step attachment strategy can be used to complete the attachment of the back film BF. For example, in step S120, back film materials such as the first back film material BFMA, the second back film material BFMB, and the third back film material BFMC can be obtained first; the first back film material BFMA includes a first release film RFA and a film material to be attached located on one side of the first release film RFA and used to be attached to the main part AA; the second back film material BFMB includes a second release film RFB and a film material to be attached located on one side of the second release film RFB and used to be attached to the adjacent part BB; the third back film material BFMC includes a third release film RFC and a film material to be attached located on one side of the third release film RFC and used to be attached to the binding part CC. Each back film material can be attached in sequence, and the release film can be torn off after any back film material is attached. It is understandable that each back film material may further include a protective layer covering the film material to be attached away from the release film; before attaching the back film material to the back of the flexible display panel PNL, the protective layer may be torn off to expose the film material to be attached.

[0103] In one embodiment of the present disclosure, step S120 includes: obtaining a first back film material BFMA, a second back film material BFMB and a third back film material BFMC; the first back film material BFMA includes a first release film RFA and a first back film portion BFA located on one side of the first release film RFA and used to be attached to the back side of the main part AA, the second back film material BFMB includes a second release film RFB and a second back film portion BFB located on one side of the second release film RFB and used to be attached to the back side of the adjacent part BB, the third back film material BFMC includes a third release film RFC and a third back film portion BFC located on one side of the third release film RFC and used to be attached to the back side of the binding part CC. The first back film part BFA is attached to the back side of the main part AA through the first back film material BFMA; the second back film part BFB is attached to the back side of the adjacent part BB through the second back film material BFMB; the third back film part BFC is attached to the back side of the binding part CC through the third back film material BFMC.

[0104] In this embodiment, see Fig.12, the film material to be attached of the first back film material BFMA is the first back film portion BFA. After the first back film material BFMA is attached to the back of the flexible display panel PNL, the first release film RFA can be torn off to complete the attachment of the first back film portion BFA. It can be understood that if the first back film portion BFA is bonded to the flexible display panel PNL through the adhesive layer OC, the first adhesive layer OCA can also be provided on the surface of the first back film portion BFA away from the first release film RFA, so that the film material to be attached of the first back film material BFMA is the stacked first back film portion BFA and the first adhesive layer OCA.

[0105] Furthermore, the first back film material BFMA may also include a first filling layer DUMA located at the adjacent portion BB, the binding bend portion DD and the binding portion CC, and the first filling layer DUMA has the same thickness as the film material to be attached on the first back film material BFMA. In this way, the first filling layer DUMA can keep the first back film material BFMA intact and reduce the risk of deformation of the first back film material BFMA. The first filling layer DUMA can be torn off separately after being attached to the back of the flexible display panel PNL, or it can be torn off together with the first release film RFA when the first release film RFA is torn off. When the first back film material BFMA has a protective layer covering the film material to be attached, the first filling layer DUMA can also be torn off when the protective film is torn off.

[0106] In one example, see Fig.12 The film material to be attached of the first back film material BFMA is the first back film part BFA; the first back film material BFMA also includes a first filling layer DUMA, the first filling layer DUMA and the first back film part BFA are located on the same side of the first release film RFA and are spliced ​​with each other and have the same thickness.

[0107] In another example, the first backing film material BFMA further includes a first adhesive layer OCA located on the side of the first backing film portion BFA away from the first release film RFA; in this case, the film material to be attached of the first backing film material BFMA is the first backing film portion BFA and the first adhesive layer OCA which are stacked. The first backing film material BFMA further includes a first filling layer DUMA, the first filling layer DUMA and the first backing film portion BFA are located on the same side of the first release film RFA and are spliced ​​with each other; the thickness of the first filling layer DUMA is the same as the total thickness of the first backing film portion BFA and the first adhesive layer OCA.

[0108] In this embodiment, see Fig.13, the film material to be attached of the second back film material BFMB is the second back film part BFB. After the second back film material BFMB is attached to the back of the flexible display panel PNL, the second release film RFB can be torn off to complete the attachment of the second back film part BFB. It can be understood that if the second back film part BFB is bonded to the flexible display panel PNL through the adhesive layer OC, the second adhesive layer OCB can also be provided on the surface of the second back film part BFB away from the second release film RFB, so that the film material to be attached of the second back film material BFMB is the stacked second back film part BFB and the second adhesive layer OCB.

[0109] Furthermore, the second back film material BFMB may also include a second filling layer DUMB located at the main part AA, the binding bending part DD and the binding part CC, and the second filling layer DUMB has the same thickness as the film material to be attached on the second back film material BFMB. In this way, the second filling layer DUMB can keep the second back film material BFMB intact and reduce the risk of deformation of the second back film material BFMB. The second filling layer DUMB can be torn off separately after being attached to the back of the flexible display panel PNL, or it can be torn off together with the second release film RFB when the second release film RFB is torn off. When the second back film material BFMB has a protective layer covering the film material to be attached, the second filling layer DUMB can also be torn off when the protective film is torn off.

[0110] In one example, see Fig.13 The film material to be attached to the second back film material BFMB is the second back film part BFB; the second back film material BFMB also includes a second filling layer DUMB, the second filling layer DUMB and the second back film part BFB are located on the same side of the second release film RFB and are spliced ​​with each other and have the same thickness.

[0111] In another example, the second back film material BFMB further includes a second adhesive layer OCB located on the side of the second back film portion BFB away from the second release film RFB; in this case, the film material to be attached of the second back film material BFMB is the second back film portion BFB and the second adhesive layer OCB which are stacked. The second back film material BFMB further includes a second filling layer DUMB, and the second filling layer DUMB and the second back film portion BFB are located on the same side of the second release film RFB and are spliced ​​with each other; the thickness of the second filling layer DUMB is the same as the total thickness of the second back film portion BFB and the second adhesive layer OCB.

[0112] In this embodiment, see Fig.14, the film material to be attached of the third back film material BFMC is the third back film part BFC. After the third back film material BFMC is attached to the back of the flexible display panel PNL, the third release film RFC can be torn off to complete the attachment of the third back film part BFC. It can be understood that if the third back film part BFC is bonded to the flexible display panel PNL through the adhesive layer OC, the third adhesive layer OCC can also be provided on the surface of the third back film part BFC away from the third release film RFC, so that the film material to be attached of the third back film material BFMC is the laminated third back film part BFC and the third adhesive layer OCC.

[0113] Furthermore, the third back film material BFMC may also include a third filling layer DUMC located in the main part AA, the adjacent part BB and the binding bending part DD, and the third filling layer DUMC has the same thickness as the film material to be attached on the third back film material BFMC. In this way, the third filling layer DUMC can keep the third back film material BFMC intact and reduce the risk of deformation of the third back film material BFMC. The third filling layer DUMC can be torn off separately after being attached to the back of the flexible display panel PNL, or it can be torn off together with the third release film RFC when the third release film RFC is torn off. When the third back film material BFMC has a protective layer covering the film material to be attached, the third filling layer DUMC can also be torn off as the protective film is torn off.

[0114] In one example, see Fig.12 The film material to be attached of the third back film material BFMC is the third back film part BFC; the third back film material BFMC also includes a third filling layer DUMC, the third filling layer DUMC and the third back film part BFC are located on the same side of the third release film RFC and are spliced ​​with each other and have the same thickness.

[0115] In another example, the third back film material BFMC further includes a third adhesive layer OCC located on the side of the third back film portion BFC away from the third release film RFC; in this case, the film material to be attached of the third back film material BFMC is the third back film portion BFC and the third adhesive layer OCC which are stacked. The third back film material BFMC further includes a third filling layer DUMC, the third filling layer DUMC and the third back film portion BFC are located on the same side of the third release film RFC and are spliced ​​with each other; the thickness of the third filling layer DUMC is the same as the total thickness of the third back film portion BFC and the third adhesive layer OCC.

[0116] The present disclosure also provides a display device, which includes any one of the flexible display modules described in the above flexible display module embodiments. The display device can be a smartphone screen, a foldable laptop screen, or other types of display devices. Since the display device includes any one of the flexible display modules described in the above flexible display module embodiments, it has the same beneficial effects, and the present disclosure will not repeat them here.

[0117] It should be noted that, although the steps of the method for preparing a flexible display module in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired result. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0118] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A flexible display module, characterized in that: It comprises a flexible display panel and a back film attached to the back of the flexible display panel; wherein the flexible display panel comprises a main body portion, an adjacent portion, a binding bending portion, and a binding portion arranged in sequence; The back film includes a first back film portion attached to the main body portion, a second back film portion attached to the adjacent portion, and a third back film portion attached to the binding portion; The first back film portion, the second back film portion and the third back film portion have the same thickness, and the elastic modulus of the first back film portion is smaller than the elastic modulus of the second back film portion and the elastic modulus of the third back film portion.

2. The flexible display module according to claim 1, characterized in that: The elastic modulus of the first back film portion is between 1 and 5 GPa.

3. The flexible display module according to claim 1, characterized in that: The elastic modulus of the third back membrane portion is not less than 7 GPa.

4. The flexible display module according to claim 1, characterized in that: The thickness of the back film is between 25 and 60 microns.

5. The flexible display module according to claim 1, characterized in that: The elastic modulus of the third back film portion is between 7 and 12 GPa; and the thickness of the back film is between 45 and 55 microns.

6. The flexible display module according to claim 1, characterized in that: The material of the third back film portion is metal, and the thickness of the back film is between 25 and 35 microns.

7. The flexible display module according to claim 1, characterized in that: The back film is adhered to the back side of the flexible display panel through an adhesive layer.

8. A method for preparing a flexible display module, characterized in that: include: obtaining a flexible display panel; The flexible display panel comprises a main body portion, an adjacent portion, a binding bending portion, and a binding portion which are arranged in sequence; A back film is attached to the back of the flexible display panel; the back film includes a first back film portion attached to the main body portion, a second back film portion attached to the adjacent portion, and a third back film portion attached to the binding portion; The first back film portion, the second back film portion and the third back film portion have the same thickness, and the elastic modulus of the first back film portion is smaller than the elastic modulus of the second back film portion and the elastic modulus of the third back film portion.

9. The method for preparing a flexible display module according to claim 8, characterized in that: Attaching a back film to the back of the flexible display panel includes: Obtain a back film material, the back film material comprising a release film and a back film located on one side of the release film, the back film package comprising a first back film portion for attaching to the main body portion, a second back film portion for attaching to the adjacent portion, and a third back film portion for attaching to the binding portion; The back film of the back film material is attached to the back side of the flexible display panel, and then the release film is torn off.

10. The method for preparing a flexible display module according to claim 8, characterized in that: Attaching a back film to the back of the flexible display panel includes: Obtain a first back film material, a second back film material and a third back film material; the first back film material includes a first release film and a first back film portion located on one side of the first release film, the second back film material includes a second release film and a second back film portion located on one side of the second release film, and the third back film material includes a third release film and a third back film portion located on one side of the third release film; The first back film portion is attached to the back side of the main body portion through the first back film material; the second back film portion is attached to the back side of the adjacent portion through the second back film material; and the third back film portion is attached to the back side of the binding portion through the third back film material.

11. The method for preparing a flexible display module according to claim 10, characterized in that: The first backing film material further includes a first filling layer, wherein the first filling layer and the first backing film portion are located on the same side of the first release film and are spliced ​​with each other and have the same thickness; The second backing film material further includes a second filling layer, and the second filling layer and the second backing film portion are located on the same side of the second release film and are spliced ​​with each other and have the same thickness; The third back film material further includes a third filling layer. The third filling layer and the third back film portion are located on the same side of the third release film and are spliced ​​with each other and have the same thickness.

12. The method for preparing a flexible display module according to claim 11, characterized in that: The first backing film material further includes a first adhesive layer located on a side of the first backing film portion away from the first release film; the thickness of the first filling layer is the same as the total thickness of the first backing film portion and the first adhesive layer; The second backing film material further includes a second adhesive layer located on a side of the second backing film portion away from the second release film; the thickness of the second filling layer is the same as the total thickness of the second backing film portion and the second adhesive layer; The third backing film material further includes a third adhesive layer located on a side of the third backing film portion away from the first release film; the thickness of the third filling layer is the same as the total thickness of the third backing film portion and the third adhesive layer.

13. A display device comprising the flexible display module according to any one of claims 1 to 7.

Images