CN110335970B

CN110335970B - Flexible display substrate, manufacturing method thereof and flexible display device

Info

Publication number: CN110335970B
Application number: CN201910639614.7A
Authority: CN
Inventors: 宫奎; 张志海
Original assignee: BOE Technology Group Co Ltd; Hefei BOE Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Hefei BOE Optoelectronics Technology Co Ltd
Priority date: 2019-07-15
Filing date: 2019-07-15
Publication date: 2022-01-18
Anticipated expiration: 2039-07-15
Also published as: CN110335970A

Abstract

The application discloses a flexible display substrate, a manufacturing method thereof and a flexible display device, and belongs to the technical field of display. The method comprises the following steps: forming a flexible substrate on a rigid substrate; forming a heat insulation layer and a heat conduction layer on the rigid substrate on which the flexible substrate is formed; forming a display structure on the rigid substrate on which the heat-insulating layer and the heat-conducting layer are formed; and peeling the rigid substrate to obtain the flexible display substrate. The display structure of the flexible display substrate can be prevented from being burnt by heat generated in the process of peeling the rigid substrate by laser, and the influence of the process of peeling the rigid substrate on the quality of the flexible display substrate is reduced. The application is used for manufacturing the flexible display substrate.

Description

Flexible display substrate, manufacturing method thereof and flexible display device

Technical Field

The present disclosure relates to the field of display technologies, and in particular, to a flexible display substrate, a manufacturing method thereof, and a flexible display device.

Background

With the development of semiconductor display devices and the increasing consumer demand of consumers, flexible display substrates have been greatly promoted to the market, and are widely applied to flexible display devices such as curved-screen mobile phones, curved-screen vehicle-mounted devices, wearable devices and the like.

At present, a flexible substrate and a display structure on the flexible substrate are usually manufactured on a rigid substrate, and then the rigid substrate is peeled off by a laser peeling process to obtain a flexible display substrate.

However, in the process of peeling off the rigid substrate, the display structure of the flexible display substrate is burnt by the high-temperature heat generated by the laser, which affects the quality of the flexible display substrate.

Content of application

The application provides a flexible display substrate, a manufacturing method thereof and a flexible display device, which are beneficial to avoiding a display structure of the flexible display substrate from being burnt by heat generated in the process of peeling a rigid substrate by laser. The technical scheme is as follows:

in a first aspect, a method for manufacturing a flexible display substrate is provided, the method including:

forming a flexible substrate on a rigid substrate;

forming a heat insulating layer and a heat conductive layer on the rigid substrate on which the flexible substrate is formed;

forming a display structure on the rigid substrate on which the thermal insulating layer and the heat conductive layer are formed;

and peeling the rigid substrate to obtain the flexible display substrate.

Optionally, the thermal insulation layer and the heat conduction layer are distributed on the same layer.

Optionally, the heat insulation layer has a hollowed-out area, and the heat conduction layer is located in the hollowed-out area and is in contact with the heat insulation layer.

Optionally, the thickness of the thermal insulation layer is equal to the thickness of the heat conduction layer.

Optionally, the thermal insulation layer is made of an insulating material, and the thermal conduction layer is made of an electric conduction material.

Optionally, the material of the thermal insulation layer comprises silica aerogel, and the material of the thermal conduction layer comprises graphene.

Optionally, forming a thermal insulating layer and a thermal conductive layer on the rigid substrate formed with the flexible substrate includes: and forming the heat insulation layer and the heat conduction layer on the rigid substrate on which the flexible substrate is formed through a one-time patterning process.

Optionally, the forming the thermal insulation layer and the thermal conduction layer on the rigid substrate formed with the flexible substrate through a one-step patterning process includes:

forming a heat insulating material layer on the rigid substrate on which the flexible substrate is formed;

forming a first photoresist pattern on the rigid substrate on which the thermal insulation material layer is formed;

etching the area, which is not covered by the first photoresist pattern, on the heat insulation material layer to form a hollow area on the heat insulation material layer, so as to obtain the heat insulation layer;

forming a heat-conducting material layer on the rigid substrate on which the first photoresist pattern is formed, wherein the heat-conducting material layer is partially positioned in the hollow area;

and removing the first photoresist pattern and the heat conducting material layer positioned on the first photoresist pattern to obtain the heat conducting layer.

Optionally, forming a first photoresist pattern on the rigid substrate on which the thermal insulation material layer is formed includes:

forming a first photoresist layer on the rigid substrate on which the thermal insulation material layer is formed;

exposing the first photoresist layer by adopting a first mask, and developing the exposed first photoresist layer to obtain a first photoresist pattern;

the display structure includes: a switch unit including a gate, the forming of a display structure on the rigid substrate with the thermal insulating layer and the thermal conductive layer formed thereon, comprising:

sequentially forming a conductive material layer and a second photoresist layer on the rigid substrate on which the heat insulation layer and the heat conduction layer are formed, wherein the polarity of the second photoresist layer is opposite to that of the first photoresist layer;

exposing the second photoresist layer by using the first mask, and developing the exposed second photoresist layer to obtain a second photoresist pattern;

etching the area, which is not covered by the second photoresist pattern, on the conductive material layer to form the grid electrode, wherein the grid electrode is in superposed contact with the heat conduction layer, and the orthographic projection of the grid electrode on the flexible substrate is superposed with the orthographic projection of the heat conduction layer on the flexible substrate;

and removing the second photoresist pattern.

Optionally, the display structure comprises a light emitting unit and the switching unit,

forming a display structure on the rigid substrate on which the thermal insulating layer and the thermal conductive layer are formed, further comprising: sequentially forming a gate insulating layer, an active layer, an interlayer dielectric layer and a source drain layer on the rigid substrate on which the gate is formed to obtain the switch unit;

the method further comprises the following steps: sequentially forming a passivation layer, a planarization layer and a pixel defining layer on the rigid substrate on which the switching unit is formed;

forming a display structure on the rigid substrate on which the thermal insulating layer and the thermal conductive layer are formed, further comprising: sequentially forming an anode, a light-emitting layer and a cathode on one side of the flat layer far away from the rigid substrate to obtain the light-emitting unit, wherein the light-emitting unit is positioned in a pixel opening defined by the pixel defining layer;

before forming the thermal and thermal conductive layers on the rigid substrate on which the flexible substrate is formed, the method further includes: forming a buffer layer on the rigid substrate on which the flexible substrate is formed;

the forming of the thermal insulating layer and the thermal conductive layer on the rigid substrate on which the flexible substrate is formed includes: forming the thermal insulation layer and the thermal conductive layer on the rigid substrate on which the buffer layer is formed.

In a second aspect, a flexible display substrate is provided, the flexible display substrate comprising:

a flexible substrate;

a thermally insulating layer and a thermally conductive layer on the flexible substrate;

and the display structure is positioned on one side of the heat insulation layer and one side of the heat conduction layer, which are far away from the flexible substrate.

Optionally, the display structure includes a light emitting unit and a switch unit, the switch unit includes a gate, a gate insulating layer, an active layer, an interlayer dielectric layer, and a source drain layer, which are sequentially distributed along a direction away from the flexible substrate, and the light emitting unit includes an anode, a light emitting layer, and a cathode, which are sequentially distributed along a direction away from the flexible substrate;

the flexible display substrate further includes: the light emitting device comprises a flexible substrate, a heat insulation layer, a buffer layer, a passivation layer, a flat layer and a pixel boundary layer, wherein the buffer layer is positioned between the flexible substrate and the heat insulation layer, the passivation layer, the flat layer and the pixel boundary layer are positioned on one side, away from the flexible substrate, of the switch unit, and the light emitting unit is positioned in a pixel opening defined by the pixel boundary layer.

In a third aspect, a flexible display device is provided, which includes the flexible display substrate according to any one of the second aspect.

The beneficial effect that technical scheme that this application provided brought is:

the embodiment of the application provides a flexible display substrate and a manufacturing method thereof, and a flexible display device, because the flexible substrate is arranged on the rigid substrate, and a heat-insulating layer and a heat-conducting layer are arranged between the flexible substrate and the display structure, in the process of peeling off the rigid substrate by adopting a laser peeling process, the heat-insulating layer can isolate heat generated by laser, and the heat-conducting layer can lead out the heat generated by the laser from the display substrate, so that the display structure can be prevented from being burnt by the heat generated by the laser, and the influence of the process of peeling off the rigid substrate on the quality of the flexible display substrate is reduced.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of a method of manufacturing a flexible display substrate according to an embodiment of the present disclosure;

fig. 2 is a flowchart of a method of manufacturing another flexible display substrate according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram illustrating a flexible substrate formed on a rigid substrate according to an embodiment of the present disclosure;

fig. 4 is a schematic diagram illustrating a buffer layer formed on a rigid substrate formed with a flexible substrate according to an embodiment of the present disclosure;

fig. 5 is a flowchart of a method for forming a thermal insulation layer and a thermal conductive layer on a rigid substrate formed with a buffer layer according to an embodiment of the present disclosure;

fig. 6 is a schematic view illustrating a thermal insulation material layer formed on a rigid substrate on which a buffer layer is formed according to an embodiment of the present disclosure;

FIG. 7 is a diagram illustrating a first photoresist layer formed on a rigid substrate with a thermal insulation material layer formed thereon according to an embodiment of the disclosure;

FIG. 8 is a schematic view of a first photoresist layer being exposed according to an embodiment of the present disclosure;

FIG. 9 is a schematic view of a first photoresist layer after being developed according to an embodiment of the present application;

FIG. 10 is a schematic diagram illustrating an etched region of a thermal insulating material layer not covered by a first photoresist pattern according to an embodiment of the present disclosure;

fig. 11 is a schematic view illustrating a thermal conductive material layer formed on a rigid substrate having a first photoresist pattern formed thereon according to an embodiment of the present disclosure;

FIG. 12 is a schematic view of the first photoresist pattern and the thermal conductive material layer on the first photoresist pattern removed according to an embodiment of the disclosure;

fig. 13 is a flowchart of a method for forming a switch unit on a rigid substrate formed with a thermal insulating layer and a thermal conductive layer according to an embodiment of the present disclosure;

fig. 14 is a schematic view illustrating a rigid substrate formed with a thermal insulation layer and a thermal conduction layer, on which a second photoresist layer and a conductive material layer are sequentially formed according to an embodiment of the present disclosure;

FIG. 15 is a schematic view of a second photoresist layer being exposed according to an embodiment of the present application;

FIG. 16 is a schematic view of a second photoresist layer after being developed according to an embodiment of the present application;

fig. 17 is a schematic diagram illustrating a region of the conductive material layer not covered by the second photoresist pattern after etching according to an embodiment of the disclosure;

FIG. 18 is a schematic view of a second photoresist pattern removed according to an embodiment of the present application;

fig. 19 is a schematic diagram illustrating a gate insulating layer, an active layer, an interlayer dielectric layer, and a source drain layer sequentially formed on a rigid substrate on which a gate electrode is formed according to an embodiment of the present disclosure;

fig. 20 is a schematic diagram illustrating a passivation layer and a planarization layer sequentially formed on a rigid substrate on which a switching unit is formed according to an embodiment of the present disclosure;

fig. 21 is a schematic view of a light-emitting unit and a pixel defining layer formed on a rigid substrate with a planarization layer formed thereon according to an embodiment of the present disclosure;

FIG. 22 is a schematic diagram of a method for peeling a rigid substrate by a laser peeling process according to an embodiment of the present disclosure;

fig. 23 is a schematic structural diagram of a flexible display substrate according to an embodiment of the present application.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in further detail with reference to the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

With the development of display technology, flexible display devices represented by Organic Light-Emitting Diode (OLED) display devices are increasingly used. The main display component of the flexible display device is a flexible display substrate, the flexible display substrate uses a flexible substrate formed by Polyimide (PI) as a substrate to replace a glass substrate in the rigid display substrate, and uses a Thin Film Encapsulation (TFE) structure to replace an Encapsulation substrate in the rigid display substrate, and the flexible display substrate has the characteristics of lightness, thinness, flexibility and foldability, and can meet the development requirements of users on the display device.

In the using process of the flexible display device, a user finds that the periphery of the screen of the flexible display device is greenish, and particularly when the screen displays a background with low brightness such as gray, the phenomenon is particularly obvious. The OLED experts believe that this phenomenon occurs because the green light-emitting layer of the flexible display substrate is burned by the high temperature heat generated by the laser when the rigid substrate is peeled off using the laser peeling process during the process of manufacturing the flexible display substrate.

Referring to fig. 1, which shows a method flowchart of a method for manufacturing a flexible display substrate according to an embodiment of the present application, referring to fig. 1, the method may include the following steps:

in step 101, a flexible substrate is formed on a rigid substrate.

In step 102, a thermally insulating layer and a thermally conductive layer are formed on a rigid substrate formed with a flexible base.

In step 103, a display structure is formed on a rigid substrate having a thermally insulating layer and a thermally conductive layer formed thereon.

In step 104, the rigid substrate is peeled off to obtain the flexible display substrate.

To sum up, the manufacturing method of the flexible display substrate provided by the embodiment of the application, because the flexible substrate is arranged on the rigid substrate, and the heat-insulating layer and the heat-conducting layer are arranged between the flexible substrate and the display structure, in the process of peeling off the rigid substrate by adopting the laser peeling process, the heat-insulating layer can isolate the heat generated by the laser, and the heat-conducting layer can lead out the heat generated by the laser from the flexible display substrate, so that the display structure can be prevented from being burnt by the heat generated by the laser, and the influence of the process of peeling off the rigid substrate on the quality of the flexible display substrate is reduced.

Referring to fig. 2, which shows a method flowchart of another method for manufacturing a flexible display substrate according to an embodiment of the present disclosure, referring to fig. 2, the method may include the following steps:

in step 201, a flexible base is formed on a rigid substrate.

The material of the rigid substrate may be a light-guiding and non-metallic transparent material with certain robustness, for example, the material of the rigid substrate may be one or a combination of more of glass, quartz or transparent resin. The flexible substrate may be a single-layer structure or a multi-layer structure, for example, the flexible substrate may be a single-layer organic layer, or the flexible substrate may be a multi-layer structure in which organic layers and inorganic layers are alternately stacked. The material of the organic layer may be an organic transparent material, for example, the material of the organic layer may be one or a combination of more of PI, Polyethylene naphthalate (PEN), Polyethylene terephthalate (PET), Polyarylate (PAR), Polycarbonate (PC), Polyethersulfone (PES), or Polyetherimide (PEI).

Referring to fig. 3, a schematic diagram of a flexible substrate 101 formed on a rigid substrate 00 according to an embodiment of the present application is shown, where fig. 3 illustrates the flexible substrate 101 as a single-layer structure. As shown in fig. 3, the flexible substrate 101 covers the rigid substrate 00. For example, taking the material of the flexible substrate 101 as PI, a layer of PI solution may be coated on the rigid substrate 00, and then the coated PI solution is dried to obtain the flexible substrate 101.

In step 202, a buffer layer is formed on a rigid substrate formed with a flexible base.

The buffer layer can protect a subsequently formed display structure and is beneficial to preventing external water vapor from invading a film layer in the display structure, and the buffer layer can be made of one or a combination of SiOx (Chinese: silicon oxide) or SiNx (Chinese: silicon nitride).

Referring to fig. 4, a schematic diagram of a buffer layer 102 formed on a rigid substrate 00 with a flexible substrate 102 formed thereon according to an embodiment of the present disclosure is shown, where the buffer layer 102 covers the flexible substrate 102. For example, SiOx is used as a material, and the buffer layer 102 is formed on the rigid substrate 00 on which the flexible substrate 102 is formed by any one of sputtering, thermal evaporation, or deposition.

In step 203, a thermal insulating layer and a thermal conductive layer are formed on the rigid substrate on which the buffer layer is formed.

The heat-insulating layer and the heat-conducting layer can be distributed on the same layer, and the thickness of the heat-insulating layer and the thickness of the heat-conducting layer can be equal. For example, the thermal insulation layer has a hollow-out region, and the heat conduction layer is located in the hollow-out region and is in contact with the thermal insulation layer, so that the thermal insulation layer and the heat conduction layer can be distributed in the same layer.

In the embodiment of the present application, the thermal insulating layer and the thermal conductive layer may be formed on the rigid substrate on which the buffer layer is formed through a one-time patterning process. Referring to fig. 5, which shows a flowchart of a method for forming a thermal insulating layer and a thermal conducting layer on a buffer layer formed rigid substrate through a one-step patterning process according to an embodiment of the present application, referring to fig. 5, the method may include the following sub-steps:

in sub-step 2031, a thermal insulating material layer is formed on the rigid substrate on which the buffer layer is formed.

The material of the thermal insulation material layer may be an insulation material with good thermal insulation performance, and in the embodiment of the present application, the material of the thermal insulation material layer may include SiO₂(Chinese: silica) aerogel. SiO 2₂The aerogel has a refractive index between that of liquid and gas, has the characteristics of low thermal conductivity, low refractive index, high light transmittance, solid state and the like, is an effective heat-insulating material, and is SiO₂Thermal insulation effect of aerogel and SiO₂The extremely low bulk density of the aerogel itself is related to the large number of voids within it, and it has been found through research that SiO can be made by appropriate means₂The aerogel has a nano porous network structure, so that SiO can be generated₂The aerogel has extremely low solid and gaseous heat conduction performance, the heat conductivity can be as low as 0.013W/m.K (Watts per meter per Kelvin) at normal temperature, and the aerogel is a better heat-insulating material in solid materials. At present, SiO₂Aerogels are widely used in aerospace vehicles, ground, underground, water and underwater vehicles, construction facilities, and industrial and agricultural equipment, etc., and are generally coated on a substrate with SiO by a coating method₂Aerogel to utilize SiO₂The aerogel is used for manufacturing a heat preservation and insulation film.

Referring to fig. 6, a schematic diagram of a thermal insulation material layer a formed on a rigid substrate 00 with a buffer layer 102 formed thereon according to an embodiment of the present disclosure is shown, wherein the thermal insulation material layer a covers the buffer layer 102, and the thickness of the thermal insulation material layer a may be 50 to 500nm (nanometers). For example, one of the coating processes such as spin coating and spray coating may be used to coat a layer of SiO with a thickness of 50-500 nm on the rigid substrate 00 on which the buffer layer 102 is formed₂Aerogel, and to coated SiO₂And drying the aerogel to obtain a heat insulation material layer A.

As will be readily understood by those skilled in the art, inPrior to performing substep 2031, SiO may be pre-prepared₂An aerogel. In the embodiment of the application, the SiO can be prepared by adopting a one-step method or a two-step method₂An aerogel. Preparation of SiO by two-step method₂The aerogel is prepared by sequentially carrying out acid catalysis and alkaline catalysis on silicon monomer serving as a preparation raw material to obtain SiO₂The aerogel is characterized in that under the acidic catalysis condition, silicon monomers undergo slow polycondensation to form silicon-oxygen bonds in a polymer shape to obtain gel of a weakly crosslinked and low-density network, and under the alkaline catalysis condition, silicic acid monomers in the gel of the weakly crosslinked and low-density network are hydrolyzed and then rapidly polycondensed to generate relatively compact colloidal particles to obtain SiO (silicon oxide) particles₂Aerogels, wherein the size of the colloidal particles depends on the preparation conditions. SiO 2₂The structure of the aerogel depends primarily on the reaction rate of hydrolysis and polycondensation of the components. Preparation of SiO by two-step method₂The aerogel can obtain SiO with high porosity and low volume density₂Aerogel, SiO measured and prepared by a two-step process₂The porosity of the material can reach more than 97 percent (SiO)₂The linear density of the aerogel is 4nm, the size of the holes is 1-30 nm, and the SiO prepared by adopting a one-step method₂The linear density of the aerogel is 10-50 nm, and the size of the holes is 1-100 nm. Preparation of SiO by two-step method₂The optical transmittance of the aerogel is higher.

Wherein, the SiO is prepared by adopting a two-step method₂The process of aerogel may include: firstly, using tetraethoxysilane (TEOS for short) as precursor, adding proper quantity of ethyl alcohol and hydrochloric acid, mixing them at room temp. and fully stirring them for above 30 min, standing the mixed solution for 100 min under the condition of 60 deg.C to make it undergo the processes of hydrolysis and polycondensation reaction, then dripping proper quantity of ammonia water solution into said mixed solution, stirring at room temp. for 30 min, sealing and transferring into drying environment (relative humidity is less than 60%), ageing for 1-5 days to obtain the invented product₂And (4) preparing the aerogel. It is noted that the examples of the present application provide for the preparation of SiO₂The method of preparing the aerogel is merely an example, and the SiO is prepared₂The aerogel method is not limited to the two-step method, and the examples of the present application are forThis is not limiting.

In sub-step 2032, a first photoresist layer is formed on the rigid substrate on which the thermal insulating material layer is formed.

The first photoresist layer may be a negative photoresist layer.

Fig. 7 is a schematic diagram illustrating a first photoresist layer G formed on a rigid substrate 00 with a thermal insulation material layer a formed thereon according to an embodiment of the present disclosure, wherein the first photoresist layer G covers the thermal insulation material layer a. For example, a negative photoresist may be coated as the first photoresist layer G on the rigid substrate 00 on which the thermal insulation material layer a is formed.

In sub-step 2033, a first mask is used to expose the first photoresist layer, and the exposed first photoresist layer is developed to obtain a first photoresist pattern.

Referring to fig. 8, a schematic diagram of exposing a first photoresist layer G using a first mask X according to an embodiment of the present application is shown, the first reticle X may have a light-transmitting region (not labeled in fig. 8) and a light-blocking region (not labeled in fig. 8), as shown in fig. 8, the first mask X may be disposed on a side of the first photoresist layer G away from the rigid substrate 00, such that the first photoresist layer G is located between the rigid substrate 00 and the first mask X, and the first mask X is aligned with the rigid substrate 00 on which the first photoresist layer G is formed, then, a light source (not shown in fig. 8) is used to irradiate the first mask X, so that the light emitted from the light source is irradiated to the first photoresist layer G through the light-transmitting area of the first mask X, the areas of the first photoresist layer G irradiated by light are photosensitive, and the areas not irradiated by light are not photosensitive.

After the first photoresist layer G is exposed, the exposed first photoresist layer G may be developed. For example, referring to fig. 9, which shows a schematic diagram of the exposed first photoresist layer G after development according to an embodiment of the present application, with reference to fig. 8 and 9, since the first photoresist layer G is a negative photoresist layer, after the exposed first photoresist layer G is developed, an unexposed portion of the first photoresist layer G can be removed, so that a photosensitive portion of the first photoresist layer G remains, and a first photoresist pattern G1 is obtained, where the first photoresist pattern G1 has a hollow area, and the hollow area corresponds to the unexposed area of the first photoresist layer G.

In sub-step 2034, the area of the thermal insulation material layer not covered by the first photoresist pattern is etched to form a hollow area on the thermal insulation material layer, so as to obtain the thermal insulation layer.

Referring to fig. 10, which shows a schematic diagram of a thermal insulation material layer a after etching a region not covered by the first photoresist pattern G1 according to an embodiment of the present disclosure, for example, a dry etching process may be employed to etch a region not covered by the first photoresist pattern G1 on the thermal insulation material layer a with the first photoresist pattern G1 as an anti-etching layer, and remove a region not covered by the first photoresist pattern G1 on the thermal insulation material layer a, so as to form a hollow region a1 on the thermal insulation material layer a, so that the thermal insulation material layer a forms the thermal insulation layer 103.

In sub-step 2035, a thermal conductive material layer is formed on the rigid substrate with the first photoresist pattern formed thereon, the thermal conductive material layer being partially located in the hollow area of the thermal insulation material layer.

The thickness of the heat conducting material layer is the same as that of the heat insulating layer, so that the thickness of the finally formed heat conducting layer is the same as that of the heat insulating layer, and the smoothness of the flexible display substrate is guaranteed. The material of the thermal conductive material layer may be an insulating material or an electrically conductive material with good thermal conductivity, and in this embodiment, the material of the thermal conductive material layer may include graphene. The graphene has excellent properties, for example, the graphene has ultrahigh theoretical specific surface area, excellent thermal conductivity, high strength, high modulus, high electron mobility and high electrical conductivity, and the theoretical specific surface area of the graphene can reach 2630m²g^-1(per gram of square meter), the heat conductivity coefficient can reach 5000W/m.K (Watt per meter per Kelvin), the strength can reach 130GPa (gigapascal), the modulus can reach 1060GPa (gigapascal), and the electron mobility can reach 15000cm²V · S) (square centimeter per volt per second), the conductivity can reach 7200S/cm (siemens per centimeter).

Referring to fig. 11, which is a schematic diagram illustrating a thermal conductive material layer B formed on a rigid substrate 00 having a first photoresist pattern G1 according to an embodiment of the present disclosure, referring to fig. 11 in combination with fig. 10, the thermal conductive material layer B partially covers the first photoresist pattern G1 and is partially located in a hollow area a1 of a thermal insulating layer 103, and the thickness of the thermal conductive material layer B is the same as that of the thermal insulating layer 103, and the thickness of the thermal conductive material layer B is 50 to 500nm to ensure flatness of the flexible display substrate.

For example, graphene is used as a material, and a heat conducting material layer B is formed on the rigid substrate 00 on which the first photoresist pattern G1 is formed by any one of sputtering, thermal evaporation, spin coating, spray coating, and the like, and the heat conducting material layer B is partially located on the first photoresist pattern G1 and partially located in the hollow area a1 on the thermal insulation layer 103.

In sub-step 2036, the first photoresist pattern and the layer of thermally conductive material on the first photoresist pattern are removed to obtain a thermally conductive layer.

Referring to fig. 12, which illustrates a schematic diagram of the first photoresist pattern G1 and the thermal conductive material layer B on the first photoresist pattern G1 being removed according to an embodiment of the present disclosure, for example, the first photoresist pattern G1 may be removed by an ashing process, the thermal conductive material layer B on the first photoresist pattern G1 is removed while the first photoresist pattern G1 is removed, and the thermal conductive material layer B in the hollow area a1 on the thermal insulating layer 103 remains to form the thermal conductive layer 104.

It should be noted that, in the embodiment of the present application, an example is taken to obtain a heat conduction layer after a heat conduction material layer is formed on a rigid substrate on which a first photoresist pattern is formed and the first photoresist pattern and the heat conduction material layer on the first photoresist pattern are removed, and those skilled in the art will readily understand that graphene may also be coated in a hollow area of a heat insulation material layer by using a slit coating process to obtain the heat conduction layer, which is not limited in the embodiment of the present application.

In step 204, a switch unit is formed on a rigid substrate having a thermally insulating layer and a thermally conductive layer formed thereon.

Alternatively, the switching unit may be a Thin Film Transistor (TFT), which generally includes a gate electrode, a gate insulating layer, an active layer, an interlayer dielectric layer, a source electrode, and a drain electrode.

Referring to fig. 13, which shows a flowchart of a method for forming a switch unit on a rigid substrate formed with a thermal insulation layer and a thermal conduction layer according to an embodiment of the present application, referring to fig. 13, the method may include the following sub-steps:

in sub-step 2041, a layer of electrically conductive material and a second layer of photoresist are sequentially formed on the rigid substrate with the thermally and thermally insulating layers formed thereon, the second layer of photoresist having a polarity opposite to the polarity of the first layer of photoresist.

The conductive material layer may be made of a metal material or an alloy material, for example, the conductive material layer is made of one of metal Al (chinese: aluminum), metal Cu (chinese: copper), or metal Mo (chinese: molybdenum), or the conductive material layer is made of an alloy material of a plurality of metal Al, metal Cu, or metal Mo. The second photoresist layer may be a positive photoresist layer.

Fig. 14 is a schematic diagram illustrating a conductive material layer Y and a second photoresist layer J sequentially formed on a rigid substrate 00 having a thermal insulation layer 103 and a thermal conduction layer 104 formed thereon according to an embodiment of the present disclosure, wherein the conductive material layer Y covers the thermal insulation layer 103 and the thermal conduction layer 104, and the second photoresist layer J covers the conductive material layer Y.

For example, first, a metal Al material layer may be formed as the conductive material layer Y on the rigid substrate 00 on which the thermal insulating layer 103 and the thermal conductive layer 104 are formed by any one of sputtering and thermal evaporation, and then a positive photoresist layer may be coated as the second photoresist layer J on the rigid substrate 00 on which the conductive material layer Y is formed.

In sub-step 2042, the second photoresist layer is exposed using the first mask, and the exposed second photoresist layer is developed to obtain a second photoresist pattern.

Referring to fig. 15, a schematic diagram of exposing the second photoresist layer J provided in the embodiment of the present application is shown, and the process of exposing the second photoresist layer J may refer to an implementation process of sub-step 2033 in the embodiment of the present application, which is not described herein again.

Referring to fig. 16, which shows a schematic diagram of the second photoresist layer J after being exposed to light and developed according to an embodiment of the present application, since the second photoresist layer J is a positive photoresist layer, after being exposed to light and developed, a photosensitive portion of the second photoresist layer J can be removed, so that an unexposed portion of the second photoresist layer J remains to obtain a second photoresist pattern J1. It is easily understood that, in the embodiment of the present application, the second photoresist pattern J1 is complementary to the first photoresist pattern G1.

In sub-step 2043, the region of the conductive material layer not covered by the second photoresist pattern is etched to form a gate.

Fig. 17 is a schematic diagram illustrating a region of the conductive material layer Y not covered by the second photoresist pattern J1 after etching according to an embodiment of the disclosure. Referring to fig. 17, a wet etching process may be adopted, and the second photoresist pattern J1 is used as an anti-etching layer, and the conductive material layer Y is etched to obtain the gate 1051, the gate 1051 is in superposed contact with the heat conductive layer 104, and an orthographic projection of the gate 1051 on the rigid substrate 00 coincides with an orthographic projection of the heat conductive layer 104 on the rigid substrate 00.

In the embodiment of the present application, the grid 1051 is in superposed contact with the heat conducting layer 104, so the grid 1051 is connected in parallel with the heat conducting layer 104, and since the heat conducting layer 104 is made of graphene with good electrical conductivity, the resistance of the grid 1051 can be reduced by the heat conducting layer 104. In addition, since the heat insulating layer 104 and the gate electrode 1051 are manufactured by the same mask, the use of a plurality of masks can be avoided, and the manufacturing cost of the flexible display substrate can be reduced.

In sub-step 2044, the second photoresist pattern is removed.

Referring to fig. 18, a schematic diagram of the second photoresist pattern J1 after being removed according to an embodiment of the present application is shown. Illustratively, the second photoresist pattern J1 covering the gate electrode 1051 may be removed by an ashing process.

In sub-step 2045, a gate insulating layer, an active layer, an interlayer dielectric layer, and a source drain layer are sequentially formed on the rigid substrate on which the gate is formed, the source drain layer including a source and a drain, and a switching unit is obtained.

The material of the gate insulating layer may be a transparent insulating material, for example, the material of the gate insulating layer may be SiO₂、SiOx、SiNx、Al₂O₃The active layer may be made of one or more of Oxide (Oxide), a-Si (amorphous silicon) or p-Si (polycrystalline silicon), for example, the active layer may be Indium Gallium Zinc Oxide (IGZO) or Indium Tin Zinc Oxide (ITZO), and the interlayer dielectric layer may be made of SiO₂、SiOx、SiNx、Al₂O₃Or a combination of one or more of SiOxNx, the source electrode and the drain electrode may be made of a metal material or an alloy material, for example, the source electrode and the drain electrode may be made of any one of metal materials such as metal Al, metal Cu, or metal Mo, or the source electrode and the drain electrode may be made of an alloy material of a plurality of metals such as metal Al, metal Cu, and metal Mo.

Referring to fig. 19, which shows a schematic diagram after a gate insulating layer 1052, an active layer 1053, an interlayer dielectric layer 1054, and a source drain layer (not labeled in fig. 19) are sequentially formed on a rigid substrate 00 on which a gate 1051 is formed, the gate 1051, the gate insulating layer 1052, the active layer 1053, the interlayer dielectric layer 1054, and the source drain layer are sequentially distributed along a direction away from the rigid substrate 00 to form a switch unit 105, the source drain layer includes a source 1055 and a drain 1056, the source 1055 and the drain 1056 are not in contact, and the source 1055 and the drain 1056 are respectively in contact with the active layer 1053, as shown in fig. 19, the interlayer dielectric layer 1054 has a plurality of via holes, and the source 1055 and the drain 1056 are in contact with the active layer 1053 through different via holes on the interlayer dielectric layer 1054.

Illustratively, the material of the gate insulating layer 1052 is SiO₂When the active layer 1053 is IGZO, the interlayer dielectric layer 1054 is SiOx, and the source 1055 and the drain 1056 are both made of Al, for example, the active layer 1053 and the drain 1056 are formed of IGZO and the interlayer dielectric layer is made of SiOxThe sequentially forming of the gate insulating layer 1052, the active layer 1053, the interlayer dielectric layer 1054, and the source/drain layer on the rigid substrate 00 having the gate 1051 may include: firstly, with SiO₂As a material, a gate insulating layer 1052 is formed over the rigid substrate 00 over which the gate electrode 1051 is formed by any of deposition, coating, sputtering, or the like; then, an IGZO material layer is formed on the rigid substrate 00 on which the gate insulating layer 1052 is formed by any one of deposition, coating, sputtering, or the like, and the IGZO material layer is processed by a one-step patterning process to obtain an active layer 1053; next, using SiOx as a material, an interlayer dielectric layer 1054 is formed on the rigid substrate 00 on which the active layer 1053 is formed by any one of deposition, coating, sputtering, or the like; finally, a metal Al material layer is formed on the rigid substrate 00 on which the interlayer dielectric layer 1054 is formed by any one of sputtering, thermal evaporation, and the like, and the metal Al material layer is processed by a one-step composition process to obtain the source 1055 and the drain 1056.

In step 205, a passivation layer and a planarization layer are sequentially formed on the rigid substrate on which the switching cells are formed.

Alternatively, the material of the passivation layer may be one or a combination of SiOx, SiNx, and SiOxNx, the material of the planarization layer may be a transparent organic material such as an organic resin, or the material of the planarization layer may be SiOx, SiNx, and Al₂O₃Or a transparent inorganic material such as SiOxNx.

Referring to fig. 20, which shows a schematic diagram after a passivation layer 106 and a planarization layer 107 are sequentially formed on a rigid substrate 00 on which a switching unit 105 is formed, according to an embodiment of the present disclosure, the passivation layer 106 may protect a source electrode 1055 and a drain electrode 1056, vias are respectively formed on the passivation layer 106 and the planarization layer 107, and the vias of the passivation layer 106 are communicated with the vias of the planarization layer 107.

Illustratively, taking the material of the passivation layer 106 as SiOx and the material of the planarization layer 107 as organic resin, first, a SiOx material layer may be formed on the rigid substrate 00 on which the switching units 105 are formed by any one of deposition, coating, or sputtering, and the like, the SiOx material layer is processed by a one-step patterning process to form vias on the SiOx material layer, thereby obtaining the passivation layer 106, and then, an organic resin is deposited on the rigid substrate 00 on which the passivation layer 106 is formed by any one of magnetron sputtering, thermal evaporation, or deposition, thereby obtaining a resin material layer, and the resin material layer is sequentially exposed and developed to form vias on the resin material layer, thereby obtaining the planarization layer 107.

In step 206, a light emitting unit and a pixel definition layer are formed on the rigid substrate with the planarization layer formed thereon, the light emitting unit being located in a pixel opening defined by the pixel definition layer.

The flexible display substrate may be an OLED display substrate, the light-emitting unit may be an OLED light-emitting unit, the light-emitting unit may include an anode, a light-emitting layer, and a cathode, the light-emitting layer may include an organic light-emitting layer, and in addition, the light-emitting layer may further include one or more layers of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer, or an electron injection layer.

In this embodiment, the flexible display substrate may be a top emission display substrate or a bottom emission display substrate, and when the flexible display substrate is a bottom emission display substrate, the anode is a transparent electrode and the cathode is a reflective electrode, and when the flexible display substrate is a top emission display substrate, the anode is a reflective electrode and the cathode is a transparent electrode. The transparent electrode may be made of a transparent conductive material, for example, the transparent electrode may be made of one or a combination of more of Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or aluminum-doped zinc oxide (ZnO: Al), and the reflective electrode may be made of a metal material or an alloy material, for example, the reflective electrode may be made of one or a combination of metal Al, metal Cu, or metal Mo. The material of the pixel defining layer can be one or a combination of more of polysiloxane, fluorocarbon, polyamide polymer or epoxy resin, and the material of the organic light emitting layer can be an organic light emitting material.

Referring to fig. 21, which shows a schematic diagram after forming a light emitting unit 108 and a pixel defining layer 109 on a rigid substrate 00 on which a planarization layer 107 is formed according to an embodiment of the present disclosure, the pixel defining layer 109 defines a pixel opening K, the light emitting unit 108 is located in the pixel opening K, the light emitting unit 108 includes an anode 1081, a light emitting layer 1082 and a cathode 1083, which are sequentially stacked, and the anode 1081 is sequentially connected to a drain 1056 through a via on the planarization layer 107 and a via on the passivation layer 106.

For example, taking the flexible display substrate as a bottom emission display substrate, the anode 1081 is made of ITO, the pixel defining layer 109 is made of epoxy resin, the light emitting layer 1082 is made of organic light emitting material, and the cathode 1083 is made of metal Al, then forming the light emitting unit 108 and the pixel defining layer 109 on the rigid substrate 00 with the flat layer 107 formed thereon may include: firstly, an ITO material layer may be formed on the rigid substrate 00 on which the planarization layer 107 is formed through any one of deposition, magnetron sputtering, thermal evaporation, and the like, and the ITO material layer is processed through a one-step composition process to obtain an anode 1081; then, an epoxy resin layer is formed on the rigid substrate 00 on which the anode 1081 is formed by any one of spin coating, doctor blade coating, or Chemical Vapor Deposition (CVD), and the like, and the epoxy resin layer is processed by exposure and development processes to obtain the pixel defining layer 109; then, an organic light emitting material solution is printed in the pixel opening K defined by the pixel defining layer 109 by using an inkjet printing process and dried to obtain a light emitting layer 1082, or an organic light emitting material is evaporated in the pixel opening K defined by the pixel defining layer 109 by using an evaporation process to obtain the light emitting layer 1082; finally, a metal Al material layer is formed on the light emitting layer 1082 by any one of deposition or thermal evaporation, and the metal Al material layer is processed by a one-step patterning process to obtain the cathode 1083.

It is easily understood that the display substrate may include organic light emitting layers of different colors, the organic light emitting layer of each color may be formed through one inkjet printing or one evaporation process, and the organic light emitting layers of different colors may be formed through multiple inkjet printing or multiple evaporation processes. For example, the display substrate may include a red organic light emitting layer, a green organic light emitting layer, and a blue organic light emitting layer, and the inkjet printing process may be repeatedly performed three times to form the red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer, or the evaporation process may be repeatedly performed three times to form the red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer. Generally, the green organic light emitting layer requires a higher current during driving, and the thickness of the film layer is thicker than the red organic light emitting layer and the blue organic light emitting layer, so the uniformity of the thickness of the green organic light emitting layer is generally poor, which results in different aging speeds of the light emitting layers of different colors and poor display uniformity of the display substrate. In the embodiment of the application, the green organic light emitting layer can be formed firstly, so that in the finally formed flexible display substrate, the green organic light emitting layer is closer to the flexible substrate, the display uniformity of the display substrate is ensured, and the product yield is improved.

In step 207, the rigid substrate is peeled off to obtain the flexible display substrate.

The rigid substrate may be stripped using a laser stripping process. The laser stripping process is an important process for stripping a rigid substrate in the manufacturing process of a flexible display substrate, and the main principle is as follows: the laser beam emitted by an ultraviolet excimer laser is adopted to irradiate the rigid substrate from one side of the rigid substrate, which is far away from the flexible substrate, so that the laser beam penetrates through the rigid substrate to irradiate on one surface, which is in contact with the rigid substrate, of the flexible substrate and reacts with one surface, which is in contact with the rigid substrate, of the flexible substrate, and the surface, which is in contact with the rigid substrate, of the flexible substrate is evaporated, so that the rigid substrate is separated from the flexible substrate, and the rigid substrate is peeled.

Referring to fig. 22, which shows a schematic diagram of peeling off the rigid substrate 00 by using a laser peeling process according to an embodiment of the present application, the rigid substrate 00 may be irradiated by a laser from a side of the rigid substrate 00 away from the flexible substrate 101, and the adhesive force between the flexible substrate 101 and the rigid substrate 00 is removed by the laser, so as to peel off the rigid substrate 00.

As shown in fig. 22, the orthographic projection of the light-emitting layer 1082 on the rigid substrate 00 is located on the orthographic projection of the heat-insulating layer 103 on the rigid substrate 00, and the orthographic projection of the gate 1051 on the rigid substrate 00 is overlapped with the orthographic projection of the heat-conductive layer 104 on the rigid substrate 00, so that the entire flexible display substrate is protected by the heat-insulating layer 103 and the heat-conductive layer 104. When the rigid substrate 00 is peeled off by adopting a laser peeling process, the heat-insulating layer 103 can effectively isolate high-temperature heat generated by laser, and the heat-conducting layer 104 can conduct away the high-temperature heat gathered on the heat-insulating layer 103, so that the heat accumulation is avoided from damaging a film layer of the flexible display substrate.

Referring to fig. 23, a schematic diagram of the rigid substrate 00 peeled off according to an embodiment of the present application is shown, and the flexible display substrate 10 can be obtained after the rigid substrate 00 is peeled off. As shown in fig. 23, the area where the light emitting layer 1082 is located is the display area of the flexible display substrate 10, and the area where the bank of the pixel defining layer 109 is located is the non-display area of the flexible display substrate 10.

To sum up, the manufacturing method of the flexible display substrate provided by the embodiment of the application, because the flexible substrate is arranged on the rigid substrate, and the heat-insulating layer and the heat-conducting layer are arranged between the flexible substrate and the display structure, in the process of peeling off the rigid substrate by adopting the laser peeling process, the heat-insulating layer can isolate the high-temperature heat generated by the laser, and the heat-conducting layer can lead the high-temperature heat generated by the laser out of the flexible display substrate, so that the display structure can be prevented from being burnt by the high-temperature heat generated by the laser, and the influence of the process of peeling off the rigid substrate on the quality of the flexible display substrate is reduced.

In the manufacturing method of the display substrate provided by the embodiment of the present disclosure, the related one-step composition process includes photoresist coating, exposure, development, etching, and photoresist stripping, and processing the material layer (for example, the ITO material layer) by the one-step composition process includes: firstly, a layer of photoresist is coated on a material layer (such as an ITO material layer) to form a photoresist layer, then, the photoresist layer is exposed by using a mask plate to form a fully exposed area and a non-exposed area, then, the photoresist in the fully exposed area is completely removed by adopting a developing process, the photoresist in the non-exposed area is completely remained, then, an area corresponding to the fully exposed area on the material layer (such as the ITO material layer) is etched by adopting an etching process, and finally, the photoresist in the non-exposed area is stripped to obtain a corresponding structure (such as an anode 1081). Here, it is described by taking a photoresist as a positive photoresist as an example, when the photoresist is a negative photoresist, reference may be made to the description in this paragraph for a process of a one-step patterning process, and details of the embodiments of the present disclosure are not repeated here.

The sequence of the steps of the method for manufacturing a display substrate provided in the embodiments of the present disclosure may be appropriately adjusted, and the steps may be increased or decreased according to the circumstances, and any method that can be easily conceived by those skilled in the art within the technical scope of the present disclosure is covered by the protection scope of the present disclosure, and therefore, the details are not described herein.

Based on the same inventive concept, the embodiment of the present application also provides a flexible display substrate, which may be the flexible display substrate 10 as shown in fig. 23.

Referring to fig. 23, the flexible display substrate 10 includes: a flexible substrate 101; a thermally insulating layer 103 and a thermally conductive layer 104 on the flexible substrate 101; a display structure on the side of the thermally insulating layer 103 and the thermally conductive layer 104 remote from the flexible substrate 101. As shown in fig. 23, the heat insulating layer 103 and the heat conducting layer 104 are distributed in the same layer, and the thickness of the heat insulating layer 103 is equal to that of the heat conducting layer 104. Optionally, the heat insulation layer 103 has a hollow-out region, and the heat conduction layer 104 is located in the hollow-out region and in contact with the heat insulation layer 103, so that the heat insulation layer 103 and the heat conduction layer 104 are distributed in the same layer. The heat insulating layer 103 and the heat conducting layer 104 are distributed on the same layer and have the same thickness, so that the flatness of the flexible display substrate can be ensured.

Optionally, the material of the thermal insulation layer 103 is an insulating material, for example, the material of the thermal insulation layer 103 includes silica aerogel, and the material of the thermal conduction layer 104 is an electrically conductive material, for example, the material of the thermal conduction layer 104 includes graphene.

Alternatively, as shown in fig. 23, the display structure includes a light emitting unit 108 and a switch unit 105, the switch unit 105 includes a gate electrode 1051, a gate insulating layer 1052, an active layer 1053, an interlayer dielectric layer 1054, and a source drain layer (not labeled in fig. 23) sequentially distributed in a direction away from the flexible substrate 101, the source drain layer includes a source electrode 1055 and a drain electrode 1056, the light emitting unit 108 includes an anode 1081, a light emitting layer 1082, and a cathode 1083 sequentially distributed in a direction away from the flexible substrate 101, and the anode 1081 is connected to the drain electrode 1056;

optionally, with continued reference to fig. 23, the flexible display substrate 10 further includes: the light emitting diode comprises a buffer layer 102 located between a flexible substrate 101 and a heat insulation layer 103, a passivation layer 106, a flat layer 107 and a pixel defining layer 109 located on one side of a switch unit 105 far away from the flexible substrate 101, a light emitting unit 108 located in a pixel opening defined by the pixel defining layer 109, the passivation layer 106 and the flat layer 107 having communicated through holes, and an anode 1081 connected with a drain 1056 sequentially through the through holes on the flat layer 107 and the through holes on the passivation layer 106.

It should be noted that, the detailed structure description of the flexible display substrate provided in the embodiments of the present application has been clearly described in the above method embodiments, and is not repeated herein.

To sum up, the flexible display substrate that this application embodiment provided, because thermal-protective layer and heat-conducting layer have between flexible basement and the display structure, and in making this flexible display substrate, flexible basement sets up on the rigid substrate, peel off the in-process of rigid substrate at the adoption laser lift-off technology, the heat that the thermal-protective layer can completely cut off laser production, the heat-conducting layer can be derived the heat that laser produced from the display substrate, consequently, can avoid the heat that laser produced to burn the display structure, reduce the influence of the process of peeling off the rigid substrate to the quality of flexible display substrate.

Based on the same inventive concept, an embodiment of the present application further provides a flexible display device, where the flexible display device includes the flexible display substrate provided in the above embodiment, and the flexible display device may be an electroluminescent display device, such as an OLED display device or a Quantum Dot Light Emitting diode (QLED) display device. The flexible display device can be any product or component with display function, such as electronic paper, mobile phone, television, display, digital photo frame, navigator, watch or bracelet, etc.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of manufacturing a flexible display substrate, the method comprising:

forming a flexible substrate on a rigid substrate;

forming a heat insulation layer and a heat conduction layer on the rigid substrate on which the flexible substrate is formed, wherein the heat insulation layer and the heat conduction layer are distributed on the same layer;

forming a display structure on the rigid substrate on which the thermal insulating layer and the thermal conductive layer are formed, the display structure including: a switch unit having a gate, the gate being in superimposed contact with the heat conductive layer and connected in parallel;

and stripping the rigid substrate by adopting a laser stripping process to obtain the flexible display substrate, wherein the heat conduction layer is used for guiding heat generated by laser used by the laser stripping process out of the flexible display substrate.

2. The method of claim 1,

forming a heat insulating layer and a heat conductive layer on the rigid substrate on which the flexible base is formed, including:

and forming the heat insulation layer and the heat conduction layer on the rigid substrate on which the flexible substrate is formed through a one-time patterning process.

3. The method of claim 2,

the forming the thermal insulation layer and the thermal conduction layer on the rigid substrate formed with the flexible substrate through a one-time patterning process includes:

4. The method of claim 3,

forming a first photoresist pattern on the rigid substrate on which the thermal insulation material layer is formed, including:

the forming a display structure on the rigid substrate formed with the thermal insulating layer and the thermal conductive layer includes:

etching the area, which is not covered by the second photoresist pattern, on the conductive material layer to form the grid electrode, wherein the orthographic projection of the grid electrode on the flexible substrate is superposed with the orthographic projection of the heat conduction layer on the flexible substrate;

and removing the second photoresist pattern.

5. The method of claim 4,

the display structure includes a light emitting unit and the switching unit,

6. A flexible display substrate manufactured by the method of any one of claims 1 to 5, the flexible display substrate comprising:

a flexible substrate;

7. The flexible display substrate of claim 6,

the heat insulation layer and the heat conduction layer are distributed on the same layer.

8. The flexible display substrate of claim 7,

the heat-insulating layer is provided with a hollow area, and the heat-conducting layer is located in the hollow area and is in contact with the heat-insulating layer.

9. The flexible display substrate of claim 8,

the thickness of the heat insulation layer is equal to that of the heat conduction layer.

10. The flexible display substrate of any one of claims 6 to 9,

the display structure comprises a light-emitting unit and a switch unit, wherein the switch unit comprises a grid electrode, a grid insulation layer, an active layer, an interlayer dielectric layer and a source drain layer which are sequentially distributed along the direction far away from the flexible substrate, and the light-emitting unit comprises an anode, a light-emitting layer and a cathode which are sequentially distributed along the direction far away from the flexible substrate;

11. A flexible display device, comprising: a flexible display substrate according to any one of claims 6 to 10.