Flexible substrate and flexible display device

Abstract

The embodiments of the present disclosure provide a flexible substrate and a flexible display device, which relate to the field of display technology. The flexible substrate of the present disclosure includes a flexible substrate and a metal support layer, the metal support layer includes a first area and a second area; the flexible substrate is stacked on the metal support layer, and the flexible substrate includes a third area corresponding to the first area and a fourth area corresponding to the second area; wherein the thickness of the first area is greater than the thickness of the second area, and the thickness of the third area is less than the thickness of the fourth area. The above-mentioned flexible substrate can reduce the difference in strains to which different parts of the adhesive layer in the flexible display device are subjected during the bending process, thereby reducing the probability of bubbles generated in the adhesive layer during the bending process, improving the anti-bending or anti-slip performance of the flexible display device, and extending the service life of the flexible display device.

Description

Technical Field

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

[0002] The display device can display various images through the display screen to provide various information to the user. In recent years, flexible display devices developed based on flexible substrates have greatly improved the user's convenience because they can be folded, rolled or bent like paper and are easy to carry.

[0003] In order to reduce the creases generated during repeated folding, existing flexible display devices usually apply a metal support layer with good resilience under the flexible substrate. In addition, in order to reduce the probability of the metal support layer breaking under the requirement of a small radius bend, the metal support layer usually adopts a patterned structure.

[0004] However, since the metal support layer has a large elastic modulus, the difference in strain experienced by other layers in the patterned area and the non-patterned area of ​​the corresponding metal support layer is large, and tiny bubbles are easily generated during the folding or rolling process, thereby reducing the bending or rolling resistance of the flexible display device, and even causing the flexible display device to be unable to be used normally after repeated bending or rolling.

[0005] 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

[0006] The embodiments of the present disclosure provide a flexible substrate and a flexible display device, thereby overcoming the problem of bubbles generated in the flexible optical adhesive due to the patterned structure of the metal support layer at least to a certain extent.

[0007] According to one aspect of the present disclosure, there is provided a flexible substrate, comprising:

[0008] A metal support layer including a first region and a second region;

[0009] A flexible substrate, stacked on the metal support layer, wherein the flexible substrate includes a third area corresponding to the first area and a fourth area corresponding to the second area;

[0010] The thickness of the first region is greater than the thickness of the second region, and the thickness of the third region is less than the thickness of the fourth region.

[0011] In an exemplary embodiment of the present disclosure, the flexible substrate comprises:

[0012] A back film layer, stacked on the metal support layer;

[0013] A flexible substrate layer, stacked on the back film layer;

[0014] The thickness of the third region of the back film layer is smaller than the thickness of the fourth region of the back film layer; and / or the thickness of the third region of the flexible substrate layer is smaller than the thickness of the fourth region of the flexible substrate layer.

[0015] In an exemplary embodiment of the present disclosure, the third area of ​​the back film layer is a recessed area, and the recessed direction of the recessed area is toward the metal support layer; and / or,

[0016] The third area of ​​the flexible substrate layer is a recessed area, and a recessed direction of the recessed area faces the metal support layer.

[0017] In an exemplary embodiment of the present disclosure, a cross-sectional shape of the third region along a direction perpendicular to the thickness of the flexible substrate is one or more of a rectangle, a circle, an ellipse or a diamond.

[0018] In an exemplary embodiment of the present disclosure, a chamfered structure is provided at a corner of the third region.

[0019] In an exemplary embodiment of the present disclosure, the thickness of the third region of the back film layer is 1 / 3-1 / 2 of the thickness of the fourth region of the back film layer;

[0020] The thickness of the third region of the flexible substrate layer is 1 / 3 to 1 / 2 of the thickness of the fourth region of the flexible substrate layer.

[0021] In an exemplary embodiment of the present disclosure, the thickness of the fourth area of ​​the back film layer is 30-80 micrometers; the thickness of the fourth area of ​​the flexible substrate layer is 30-80 micrometers.

[0022] In an exemplary embodiment of the present disclosure, it further includes:

[0023] A planarization layer, stacked on the flexible substrate layer;

[0024] A convex portion is provided on one side of the planarization layer close to the flexible substrate layer, and the convex portion is embedded in the third area of ​​the flexible substrate layer;

[0025] The planarization layer has a surface away from the flexible substrate layer that is flat.

[0026] In an exemplary embodiment of the present disclosure, the thickness of the second region is 0-20 micrometers.

[0027] According to one aspect of the present disclosure, a flexible display device is provided, comprising the above-mentioned flexible substrate.

[0028] In the embodiment of the present disclosure, a third region corresponding to the first region and a fourth region corresponding to the second region are provided in the flexible base of the flexible substrate, and the thickness of the third region is less than that of the fourth region, so that the third region can reduce the elastic modulus of the first region, and the fourth region can compensate for the elastic modulus of the second region, so that in the thickness direction of the flexible substrate, the sum of the elastic moduli of the first region and the third region is equal to or close to the sum of the elastic moduli of the second region and the fourth region, thereby reducing the difference in strains to which different parts of the adhesive layer in the flexible display device are subjected during the bending process, thereby reducing the probability of bubbles generated in the adhesive layer during the bending process, improving the anti-bending or anti-slipping performance of the flexible display device, and extending the service life of the flexible display device; and further improving the display effect of the flexible display device during repeated bending or sliding.

[0029] 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

[0030] 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.

[0031] Figure 1 is a schematic structural diagram of a flexible substrate in this exemplary embodiment;

[0032] Figure 2 The structure of the metal support layer in the flexible substrate according to this exemplary embodiment is shown in FIG. Figure 1 ;

[0033] Figure 3 The structure of the metal support layer in the flexible substrate according to this exemplary embodiment is shown in FIG. Figure 2 ;

[0034] Figure 4 for Figure 2 A schematic diagram of the structure of the corresponding flexible substrate;

[0035] Figure 5 for Figure 3 A schematic diagram of the structure of the corresponding flexible substrate;

[0036] Figure 6 The structure of the metal support layer in the flexible substrate according to this exemplary embodiment is shown in FIG. Figure 3 ;

[0037] Figure 7 for Figure 6 A schematic diagram of the structure of the corresponding flexible substrate;

[0038] Figure 8 is a schematic structural diagram of another flexible substrate in this exemplary embodiment;

[0039] Fig. 9 This is a schematic diagram of the structure of another flexible substrate in this exemplary embodiment;

[0040] Fig.10 For Figure 1 A corresponding schematic structural diagram of a flexible substrate;

[0041] Fig.11 FIG. 4 is a schematic diagram of the structure of a flexible display device in this exemplary embodiment.

[0042] Description of reference numerals:

[0043] 10-metal support layer; A1-first area; A2-second area; 20-flexible substrate; 201-back film layer; 202-flexible substrate layer; A3-third area; A4-fourth area; 30-functional layer; 301-base layer, 302-anode, 303-organic layer, 304-conductive layer, 305-emitting layer, 306-cathode, 307-flexible protective layer; 40-chamfered structure; 50-first adhesive layer; 51-second adhesive layer; 52-planarization layer. DETAILED DESCRIPTION

[0044] Example embodiments will now be described more fully with reference to the accompanying drawings. However, 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 descriptions will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0045] 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.

[0046] 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.

[0047] The present disclosure provides a flexible substrate to solve the problem of bubbles appearing in other layers of the flexible display device during folding or rolling due to the different thicknesses of the patterned metal support layer in the existing flexible display device. Figure 1 The flexible substrate is described in detail:

[0048] Reference Figure 1 , shows a schematic structural diagram of a flexible substrate in this example implementation, which may specifically include: a metal support layer 10 and a flexible substrate 20, wherein the metal support layer 10 includes a first area A1 and a second area A2; the flexible substrate 20 is stacked on the metal support layer 10, and the flexible substrate 20 includes a third area A3 corresponding to the first area A1 and a fourth area A4 corresponding to the second area A2; wherein the thickness of the first area A1 is greater than the thickness of the second area A2, and the thickness of the third area A3 is less than the thickness of the fourth area A4.

[0049] In this example embodiment, the flexible substrate 20 can provide a platform for processing other layers of the flexible display device, such as the functional layer. By stacking the flexible substrate 20 on the metal support layer 10, the metal support layer 10 can reduce the probability of creases being generated in the flexible substrate 20 and the functional layer during repeated folding, thereby increasing the service life of the entire flexible display device.

[0050] In practical applications, the metal support layer 10 is mostly made of metal material, stainless steel material or amorphous material, which has a high elastic modulus but low ductility. In order to reduce the probability of the metal support layer 10 breaking when bending or sliding at a small radius, the metal support layer 10 includes a first area A1 and a second area A2. By setting the thickness of the first area A1 to be greater than the thickness of the second area A2 and setting areas of different thicknesses, the flexibility of the metal support layer 10 can be improved, which is convenient for bending and reduces the probability of breaking during repeated bending.

[0051] However, due to the different thicknesses of the first area A1 and the second area A2, the elastic modulus of the metal support layer 10 in the first area A1 and the second area A2 is greatly different, which leads to a large difference in strain between the portion of the adhesive layer stacked on the flexible substrate 20 for bonding the functional layers and the portion of the adhesive layer corresponding to the first area A1 and the portion corresponding to the second area A2 during the bending process, resulting in the adhesive layer being prone to produce tiny bubbles during the bending process, reducing the anti-bending or anti-slip performance of the flexible display device, affecting the normal use of the flexible display device. The adhesive layer may be a flexible optical adhesive layer.

[0052] In this example embodiment, by providing a third area A3 corresponding to the first area A1 and a fourth area A4 corresponding to the second area A2 in the flexible substrate 20, and the thickness of the third area A3 is less than the thickness of the fourth area A4, the third area A3 can reduce the elastic modulus of the first area A1, and the fourth area A4 can compensate for the elastic modulus of the second area A2, so that in the thickness direction of the flexible substrate, the sum of the elastic moduli of the first area A1 and the third area A3 is equal to or close to the sum of the elastic moduli of the second area A2 and the fourth area A4, thereby reducing the difference in strains to which different parts of the above-mentioned adhesive layer are subjected during the bending process, thereby reducing the probability of bubbles generated in the adhesive layer during the bending process, improving the anti-bending or anti-slipping performance of the flexible display device, and extending the service life of the flexible display device; and further improving the display effect of the flexible display device during repeated bending or sliding.

[0053] In practical applications, there may be multiple first regions A1, and there may also be multiple second regions A2, and the multiple first regions A1 and the multiple second regions A2 may be arranged in a staggered manner, so that the metal support layer 10 forms a metal support layer 10 with a patterned structure. In addition, the thickness of the second region A2 may be 0-20 microns. In other words, when the thickness of the second region A2 is 0 microns, the second region A2 is a hollow region that penetrates the metal support layer 10; when the thickness of the second region A2 is greater than 0 microns, the second region A2 is a recessed region, and the recessed portion of the recessed region may be located at any position in the thickness direction of the metal support layer 10, and this example embodiment does not specifically limit this.

[0054] Reference Figure 2 , showing a schematic diagram of the structure of the metal support layer in the flexible substrate according to this exemplary embodiment Figure 1 ;reference Figure 3 , showing a schematic diagram of the structure of the metal support layer in the flexible substrate according to this exemplary embodiment Figure 2 . Figure 2In the illustrated metal supporting layer 10 , the plurality of first regions A1 and the plurality of second regions A2 are located in a partial region of the metal supporting layer 10 , for example, in a middle region in the length direction of the metal supporting layer 10 . Figure 3 In the metal support layer 10 shown, the plurality of first areas A1 and the plurality of second areas A2 occupy the entire area of ​​the metal support layer 10. In practical applications, the specific positions and areas of the first areas A1 and the second areas A2 on the metal support layer 10 can be determined according to actual needs, and this exemplary embodiment does not specifically limit this.

[0055] Corresponding to the first area A1, there may be multiple third areas A3, one third area A3 corresponds to one first area A1. Corresponding to the second area A2, there may be multiple fourth areas A4, one fourth area A4 corresponds to one second area A2. Moreover, multiple third areas A3 and multiple fourth areas A4 are arranged alternately. Figure 4 , showing Figure 2 The corresponding schematic diagram of the flexible substrate; see Figure 5 , showing Figure 3 Schematic diagram of the structure of the corresponding flexible substrate.

[0056] Figure 4 In the flexible substrate 20 shown in FIG. 1 , a plurality of third regions A3 and a plurality of fourth regions A4 are located in a partial region of the flexible substrate 20 , and the specific position of the third region A3 is different from that of the fourth region A4. Figure 2 The specific position of the first area A1 corresponds to the specific position of the fourth area A4. Figure 2 The specific position of the second area A2 in . Figure 3 Accordingly, Figure 5 In the flexible substrate 20 shown in FIG. 1 , the plurality of third areas A3 and the plurality of fourth areas A4 also occupy the entire area of ​​the flexible substrate 20 , and the specific position of the third area A3 is the same as that of the fourth area A4. Figure 3 The specific position of the first area A1 corresponds to the specific position of the fourth area A4. Figure 3 Corresponding to the specific position of the second area A2 in .

[0057] Optionally, the cross-sectional shape of the first region A1 along the direction perpendicular to the thickness of the metal support layer 10 may be one or more of a rectangle, a circle, an ellipse or a diamond, for example: Figure 2 and Figure 3 As shown, the cross-sectional shapes of the first regions A1 are all rectangular. Alternatively, in practical applications, a portion of the plurality of first regions A1 can be set as a rectangle and a portion as an ellipse. Figure 6 , showing a schematic diagram of the structure of the metal support layer in the flexible substrate according to this exemplary embodiment Figure 3 . Figure 6In the embodiment, the cross-sectional shape of the first area A1 along the direction perpendicular to the thickness of the metal support layer 10 is a rectangle, and a chamfered structure 40 is provided at the corner of the rectangle.

[0058] Among them, when the first area A1 is a protruding area, the corner refers to the connection between the adjacent side surfaces of the first area A1; when the first area A1 is a recessed area, the corner refers to the connection between the adjacent inner walls of the first area A1. In layman's terms, the corner refers to a portion with a turning point on the first area A1. The chamfered structure 40 can be a rounded structure, the purpose of which is to smooth the turning portion and reduce stress concentration at the corner. By providing the above-mentioned chamfered structure 40 at the corner, the stress concentration of the metal support layer 10 during the bending process can be reduced, the metal support layer 10 can be prevented from cracking, and the difference in strain borne by the adhesive layer can be further reduced.

[0059] Accordingly, since the third area A3 corresponds to the shape of the first area A1, the cross-sectional shape of the third area A3 along the direction perpendicular to the thickness of the flexible substrate 20 may also be one or more of a rectangle, a circle, an ellipse or a diamond. Figure 4 and Figure 5 As shown, the cross-sectional shape of the third area A3 is a rectangle. Figure 7 , showing Figure 6 Schematic diagram of the structure of the corresponding flexible substrate. Figure 7 In the figure, the cross-sectional shape of the third area A3 along the direction perpendicular to the thickness of the flexible substrate 20 is a rectangle, and the corners of the rectangle are provided with chamfer structures 40. Similarly, the chamfer structure 40 can reduce the stress concentration of the flexible substrate 20 during the bending process, avoid the occurrence of cracks in the flexible substrate 20, and further reduce the difference in strain borne by the adhesive layer.

[0060] Optionally, in this example embodiment, the flexible substrate 20 includes: a back film layer 201 and a flexible substrate layer 202, the back film layer 201 is stacked on the metal support layer 10; the flexible substrate layer 202 is stacked on the back film layer 201; the thickness of the third area A3 of the back film layer 201 is less than the thickness of the fourth area A4 of the back film layer 201; and / or the thickness of the third area A3 of the flexible substrate layer 202 is less than the thickness of the fourth area A4 of the flexible substrate layer 202.

[0061] In this exemplary embodiment, the flexible substrate layer 202 can provide a processing platform for the functional layer and other structures on the upper part of the flexible display device, and the back film layer 201 can support and protect the structure stacked thereon. By only setting the third area A3 and the fourth area A4 of different thicknesses on the back film layer 201, or only setting the third area A3 and the fourth area A4 of different thicknesses on the flexible substrate layer 202, or setting the third area A3 and the fourth area A4 of different thicknesses on the back film layer 201 and the flexible substrate layer 202 at the same time, the above three methods can achieve the purpose of setting the third area A3 and the fourth area A4 on the flexible substrate 20, so as to smooth the difference in elastic modulus between the first area A1 and the second area A2, reduce the difference in strains to which different parts of the adhesive layer on the flexible substrate 20 are subjected during the bending process, and further reduce the probability of bubbles generated in the adhesive layer during the bending process, thereby improving the anti-bending or anti-slip performance of the flexible display device and extending the service life of the flexible display device.

[0062] Reference Figure 8 , shows a schematic diagram of the structure of another flexible substrate in this example implementation mode, Figure 8 In the embodiment, only the third region A3 and the fourth region A4 with different thicknesses are provided on the back film layer 201, and the thickness of the flexible substrate layer 202 is uniform. Fig. 9 , shows a schematic structural diagram of another flexible substrate in this example implementation mode, Fig. 9 In the embodiment, only the third area A3 and the fourth area A4 with different thicknesses are provided on the flexible substrate layer 202, and the thickness of the back film layer 201 is uniform. Figure 1 As shown, the third area A3 and the fourth area A4 with different thicknesses are arranged on the back film layer 201 and the flexible substrate layer 202 .

[0063] Optionally, in this example embodiment, the third area A3 of the back film layer 201 is a recessed area, and the recessed direction of the recessed area is toward the metal support layer 10; and / or, the third area A3 of the flexible substrate layer 202 is a recessed area, and the recessed direction of the recessed area is toward the metal support layer 10.

[0064] In this exemplary embodiment, by directly setting the third area A3 as a recessed area, relative to the fourth area A4, the third area A3 is an area with a recessed portion, and the thickness of the third area A3 is smaller than that of the fourth area A4. In addition, the recessed direction of the recessed area is directed toward the metal support layer 10, that is, the recessed portion is set on the side away from the metal support layer 10, which can facilitate the bonding of the back film layer 201 to the metal support layer 10, and facilitate the bonding of the flexible substrate layer 202 to the back film layer 201. Figure 1As shown, the back film layer 201 is bonded to the metal support layer 10 through the first adhesive layer 50, and the back film layer 201 is bonded to the flexible substrate layer 202 through the second adhesive layer 51. The shapes of the first adhesive layer 50 and the second adhesive layer 51 vary according to the actual situation of the location, as long as the purpose of alignment and bonding can be achieved. The first adhesive layer 50 and the second adhesive layer 51 can be made of an optically transparent adhesive and can be applied in a coating and hardening bonding manner.

[0065] It should be noted that when only the third area A3 and the fourth area A4 with different thicknesses are provided on the flexible substrate layer 202 , the recessed direction of the recessed area of ​​the flexible substrate layer 202 can be away from the metal support layer 10 , that is, the recessed portion can be provided on a side close to the metal support layer 10 .

[0066] In practical applications, the thickness of the third area A3 of the back film layer 201 may be 1 / 3-1 / 2 of the thickness of the fourth area A4 of the back film layer 201 , and the thickness of the third area A3 of the flexible substrate layer 202 may be 1 / 3-1 / 2 of the thickness of the fourth area A4 of the flexible substrate layer 202 .

[0067] Optionally, the thickness of the fourth region A4 of the back film layer 201 is 30-80 microns; the thickness of the fourth region A4 of the flexible substrate layer 202 is 30-80 microns. Any thickness of the back film layer 201 and the flexible substrate layer 202 that can meet the requirements of the flexible display device falls within the protection scope of the present disclosure.

[0068] In practical applications, the flexible substrate layer 202 can be made of a material selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyimide, polymethyl methacrylate, silicone resin and / or polyurethane. The back film layer 201 can be made of a flexible plastic film, for example, polyimide or polyethylene terephthalate. The elastic modulus of the flexible substrate layer 202 and the back film layer 201 is basically between 9-13GPa. Whether the thickness of the flexible substrate layer 202 or the thickness of the back film layer 201 changes, the elastic modulus of the flexible substrate is affected, so that the difference in the elastic modulus in the metal support layer 10 can be compensated, so that the elastic modulus of the entire flexible substrate tends to be consistent.

[0069] In practical applications, the second adhesive layer 51 for bonding the back film layer 201 and the flexible substrate layer 202 can cover the entire back film layer 201, so as to fill the concave part of the third area A3, so that there is no gap in the middle of the entire flexible substrate, thereby improving the optical effect. It should be noted that the elastic modulus of the first adhesive layer 50 and the second adhesive layer 51 are both relatively low, generally at the KPa level, such as 50 KPa, which has little effect on the elastic modulus of the entire flexible substrate 20. Therefore, the change in the thickness of the first adhesive layer 50 or the second adhesive layer 51 can have a negligible effect on the elastic modulus of the flexible substrate 20.

[0070] Optionally, in this example embodiment, the flexible substrate 20 further includes: a planarization layer 52, which is stacked on the flexible substrate layer 202; a protrusion is provided on a side of the planarization layer 52 close to the flexible substrate layer 202, and the protrusion is embedded in the third area A3 of the flexible substrate layer 202; and a side of the planarization layer 52 away from the flexible substrate layer 202 is a plane.

[0071] In this exemplary embodiment, the planarization layer 52 is mainly provided for the case where the third area A3 of the flexible substrate layer 202 exists, that is, the flexible substrate layer 202 is a patterned structure. By providing a protrusion on one side of the planarization layer 52 close to the flexible substrate layer 202 and embedding the protrusion in the third area A3 of the flexible substrate layer 202, the third area A3 of the flexible substrate layer 202 can be filled to achieve the purpose of planarization. In addition, the side of the planarization layer 52 away from the flexible substrate layer 202 is a plane, so that the surface of the entire flexible substrate for laying other structural layers such as the functional layer is a plane, which is convenient for practical use.

[0072] It should be noted that, in the case where the recessed direction of the recessed area of ​​the flexible substrate layer 202 is away from the metal support layer 10, the planarization layer 52 may not be provided, because the side of the flexible substrate layer 202 away from the metal support layer 10 is a plane and will not affect the laying of the functional layer, etc.

[0073] In practical applications, the number, position, shape and size of the protrusions are determined according to the third area A3, as long as the protrusions and the third area A3 can be engaged with each other.

[0074] Optionally, the planarization layer 52 can be an organic material, such as acrylic resin, epoxy resin, polyimide resin and polyester resin, and the elastic modulus of the planarization layer 52 is generally between 0.5-1GPa. The thickness of the planarization layer 52 has little effect on the elastic modulus of the entire flexible substrate 20 and will not affect the adjustment of the elastic modulus of the flexible substrate 20 by the flexible base material layer 202.

[0075] Reference Fig.10 , showing the Figure 1A schematic structural diagram of a corresponding flexible substrate. Fig.10 In the embodiment, the third area A3 and the fourth area A4 with different thicknesses are arranged on the back film layer 201 and the flexible substrate layer 202 , and the chamfered structure 40 is arranged at the corner of the third area A3 , and the chamfered structure 40 is also arranged at the corner of the metal support layer 10 .

[0076] In summary, the flexible substrate provided in this exemplary embodiment has the following advantages:

[0077] In this example embodiment, by providing a third region corresponding to the first region and a fourth region corresponding to the second region in the flexible base of the flexible substrate, and the thickness of the third region is less than the thickness of the fourth region, the third region can reduce the elastic modulus of the first region, and the fourth region can compensate for the elastic modulus of the second region, so that in the thickness direction of the flexible substrate, the sum of the elastic moduli of the first region and the third region is equal to or close to the sum of the elastic moduli of the second region and the fourth region, thereby reducing the difference in strains to which different parts of the adhesive layer in the flexible display device are subjected during the bending process, thereby reducing the probability of bubbles generated in the adhesive layer during the bending process, improving the anti-bending or anti-slipping performance of the flexible display device, and extending the service life of the flexible display device; and further improving the display effect of the flexible display device during repeated bending or sliding.

[0078] In addition, in the present exemplary embodiment, a flexible display device is also provided, for example, the flexible display device can be a display device and an electronic device having the display device. One or more exemplary embodiments, for example, can be applied to computer monitors, notebook computers, digital cameras, cellular phones, smart phones, smart pads, televisions, personal digital assistants, portable multimedia players, players, navigation systems, game consoles, video phones, etc.

[0079] Reference Fig.11 , shows a schematic structural diagram of a flexible display device in this example implementation mode, such as Fig.11 As shown, the flexible display device includes the above-mentioned flexible substrate, and other structural layers including the functional layer 30 are arranged on the flexible substrate. The structure and function of the flexible substrate have been described in detail in the above-mentioned embodiments, and will not be repeated here.

[0080] Optionally, when the flexible display device is an organic light emitting diode (OLED), the functional layer 30 can be a base layer 301, an anode 302, an organic layer 303, a conductive layer 304, an emission layer 305, a cathode 306, and a flexible protective layer 307, and the above layers can be stacked.

[0081] Among them, the base layer 301 can be transparent plastic, glass or metal foil, which is mainly used to support the entire OLED; the anode 302 mainly eliminates electrons when current flows through the device; the organic layer 303 is mainly composed of organic molecules or organic polymers; the conductive layer 304 is composed of organic plastic molecules, which transport "holes" from the anode; the emission layer 305 is composed of organic plastic molecules (different from the conductive layer), which transport electrons from the cathode, and the light-emitting process takes place in this layer; when current flows in the cathode 306, the cathode injects electrons into the circuit; the flexible protective layer 307 protects other functional layers to prevent other layers from being scratched or corroded.

[0082] In summary, the flexible display device provided in this exemplary embodiment has the following advantages:

[0083] The flexible display device provided in this exemplary embodiment includes a flexible substrate and a metal support layer by providing the above-mentioned flexible substrate, wherein the metal support layer includes a first region and a second region; the flexible substrate is stacked on the metal support layer, and the flexible substrate includes a third region corresponding to the first region and a fourth region corresponding to the second region; wherein the thickness of the first region is greater than the thickness of the second region, and the thickness of the third region is less than the thickness of the fourth region. The above-mentioned flexible substrate can reduce the difference in strains to which different parts of the functional layer in the flexible display device are subjected during the bending process, thereby reducing the probability of bubbles generated in the functional layer during the bending process, improving the anti-bending or anti-slipping performance of the flexible display device, extending the service life of the flexible display device, and further improving the display effect of the flexible display device during repeated bending or sliding.

[0084] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0085] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0086] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0087] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.

[0088] The embodiments of the present disclosure are described above in conjunction with the accompanying drawings, but the present disclosure is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present disclosure, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present disclosure and the claims, all of which are within the protection of the present disclosure.

[0089] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the application 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 substrate, characterized in that: include: A metal support layer, comprising a first region and a second region, wherein the first region has a plurality of portions and the second region has a plurality of portions; A flexible substrate, stacked on the metal support layer, wherein the flexible substrate includes a third area corresponding to the first area and a fourth area corresponding to the second area; Wherein, the thickness of the first region is greater than the thickness of the second region, and the thickness of the third region is less than the thickness of the fourth region; The flexible substrate comprises a flexible substrate layer, the thickness of the third region of the flexible substrate layer is smaller than the thickness of the fourth region of the flexible substrate layer; The flexible substrate also includes a planarization layer, which is stacked on the flexible base material layer; a side of the planarization layer close to the flexible base material layer is provided with a protrusion, and the protrusion is embedded in the third area of ​​the flexible base material layer; and a side of the planarization layer away from the flexible base material layer is a plane.

2. The flexible substrate according to claim 1, characterized in that: The flexible substrate comprises a back film layer, which is stacked on the metal support layer; the thickness of the third region of the back film layer is less than the thickness of the fourth region of the back film layer, and the flexible base material layer is stacked on the back film layer.

3. The flexible substrate according to claim 2, characterized in that: The third area of ​​the back film layer is a recessed area, and the recessed direction of the recessed area is toward the metal support layer; and / or, The third area of ​​the flexible substrate layer is a recessed area, and a recessed direction of the recessed area faces the metal support layer.

4. The flexible substrate according to claim 1 or 3, characterized in that: The cross-sectional shape of the third region along a direction perpendicular to the thickness of the flexible substrate is one or more of a rectangle, a circle, an ellipse or a diamond.

5. The flexible substrate according to claim 4, characterized in that: A chamfer structure is arranged at the corner of the third area.

6. The flexible substrate according to claim 3, characterized in that: The thickness of the third region of the back film layer is 1 / 3-1 / 2 of the thickness of the fourth region of the back film layer; The thickness of the third region of the flexible substrate layer is 1 / 3 to 1 / 2 of the thickness of the fourth region of the flexible substrate layer.

7. The flexible substrate according to claim 6, characterized in that: The thickness of the fourth region of the back film layer is 30-80 micrometers; the thickness of the fourth region of the flexible substrate layer is 30-80 micrometers.

8. The flexible substrate according to claim 1, characterized in that: The thickness of the second region is 0-20 microns.

9. A flexible display device, characterized in that: Comprising the flexible substrate as described in any one of claims 1-8.

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