CN212412055U - Display panel with sandwich structure - Google Patents

Abstract

The utility model discloses a display panel with sandwich structure, including the insulating layer, the inside of insulating layer is provided with the toughness layer, the toughness on toughness layer is greater than the toughness of insulating layer. The sandwich structure in the technical scheme has better toughness, can play a role in buffering external force and offset the impact of certain external force on the insulating layer. The display panel has the advantages that the integral bending resistance of the display panel can be improved, the phenomenon that the display effect and the quality of the display panel are affected by damage to the insulating layer with high brittleness is avoided, and the display panel has more advantages.

Description

Display panel with sandwich structure

Technical Field

The utility model relates to a OLED technical field especially relates to a display panel with sandwich structure.

Background

Organic Light Emitting Diodes (OLEDs) are a trend of future display development, and OLEDs have the advantages of self-luminescence, wide viewing angle, high contrast, low power consumption, high response rate, full color, simple process, etc., and OLEDs using flexible backplane materials can make display products lighter, thinner, bendable, and less prone to breakage.

The OLED display panel is an all-solid-state thin-film device, is prepared from an organic material and an amorphous material, and can normally work in the bending and folding process, so that a flexible device is easy to prepare. The OLED display panel has an internal film layer (such as an insulating layer) with high brittleness, the brittle material has poor dynamic load resistance or impact resistance, the probability of fracture is high during bending, and the bending resistance of the display panel is influenced to a certain extent.

SUMMERY OF THE UTILITY MODEL

Therefore, it is desirable to provide a display panel having a sandwich structure, which solves the problem that the display panel is easily broken when being bent.

In order to achieve the above object, the inventors provide a display panel having a sandwich structure, including an insulating layer, the insulating layer being provided with a flexible layer inside, the flexible layer having a greater flexibility than the insulating layer.

Further, the flexible layer is a plurality of flexible blocks, and a plurality of flexible blocks are arranged among the flexible blocks; or:

the toughness layer is the multilayer, and the multilayer toughness layer stacks on top of each other and has the interval.

Further, the toughness layer is made of an organic insulating material.

Further, the display device also comprises a TFT and a display device layer;

the TFT is arranged on the insulating layer;

the display device layer is arranged on the TFT, and an anode of the display device layer is connected with a source electrode or a drain electrode of the TFT.

Be different from prior art, sandwich structure among the above-mentioned technical scheme has better toughness, can play the effect of buffering to external force, offsets the impact that some external force caused the insulating layer. The display panel has the advantages that the integral bending resistance of the display panel can be improved, the phenomenon that the display effect and the quality of the display panel are affected by damage to the insulating layer with high brittleness is avoided, and the display panel has more advantages.

Drawings

FIG. 1 is a schematic cross-sectional view illustrating a flexible substrate layer formed on a substrate according to this embodiment;

FIG. 2 is a schematic cross-sectional view illustrating a first insulating layer formed on a substrate according to the present embodiment;

FIG. 3 is a schematic cross-sectional view illustrating a flexible layer formed on a substrate according to the present embodiment;

FIG. 4 is a schematic cross-sectional view illustrating a second insulating layer formed on a substrate according to the present embodiment;

FIG. 5 is a schematic cross-sectional view illustrating a second embodiment of fabricating a plurality of ductile layers on a substrate;

FIG. 6 is a schematic cross-sectional view of a single-layer spacer sandwich structure according to a second embodiment;

FIG. 7 is a schematic cross-sectional view of a multiple layer spacer sandwich structure according to example three;

FIG. 8 is a schematic cross-sectional view illustrating an active layer formed on a substrate according to the present embodiment;

FIG. 9 is a schematic cross-sectional view illustrating a third insulating layer formed on a substrate according to the present embodiment;

FIG. 10 is a schematic cross-sectional view illustrating a gate formed on a substrate according to the present embodiment;

FIG. 11 is a schematic cross-sectional view illustrating a fourth insulating layer formed on a substrate according to the present embodiment;

FIG. 12 is a schematic cross-sectional view illustrating the source and drain formed on the substrate according to the present embodiment;

FIG. 13 is a schematic cross-sectional view of a TFT of the fourth embodiment;

FIG. 14 is a schematic cross-sectional view illustrating a fifth insulating layer formed on a substrate according to the present embodiment;

FIG. 15 is a schematic cross-sectional view illustrating a sixth insulating layer formed on a substrate according to the present embodiment;

FIG. 16 is a schematic cross-sectional view illustrating an anode fabricated on a substrate according to this embodiment;

FIG. 17 is a schematic cross-sectional view illustrating a seventh insulating layer formed on a substrate according to the present embodiment;

FIG. 18 is a schematic cross-sectional view illustrating the fabrication of an organic light-emitting layer on a substrate according to this embodiment;

FIG. 19 is a schematic cross-sectional view illustrating a cathode fabricated on a substrate according to this embodiment;

FIG. 20 is a schematic cross-sectional view illustrating a flexible cover covering a substrate according to this embodiment;

fig. 21 is a schematic cross-sectional view of a separation substrate according to the present embodiment.

Description of reference numerals:

1. a substrate;

2. a flexible substrate layer;

3. a first insulating layer;

4. a ductile layer;

5. a second insulating layer;

6. an active layer;

7. a third insulating layer;

8. a gate electrode;

9. a fourth insulating layer;

10. a source electrode;

11. a drain electrode;

12. a fifth insulating layer;

13. a sixth insulating layer;

14. an anode;

15. a seventh insulating layer;

16. an organic light emitting layer;

17. a cathode;

18. a flexible cover plate.

Detailed Description

To explain technical contents, structural features, and objects and effects of the technical solutions in detail, the following detailed description is given with reference to the accompanying drawings in conjunction with the embodiments.

Referring to fig. 1 to 21, the present embodiment provides a method for manufacturing a display panel with a sandwich structure, in which the display panel is manufactured on a substrate, such as a glass substrate or a plastic substrate. The method comprises the following steps: in order to make the substrate more stable when being bent, the substrate may be pre-treated, for example, a flexible substrate material is coated on the substrate, a flexible substrate layer 2 is formed on the substrate 1, and the substrate is made into a flexible substrate, which has a structure as shown in fig. 1. The flexible substrate layer 2 is made of Polyethylene terephthalate (abbreviated PET), Polyethylene naphthalate (abbreviated PEN), Polyimide (abbreviated PI), or other materials having similar properties. The flexible substrate materials are light in weight and good in flexibility effect, and can endow the flexible substrate with great advantages.

The OLED display panel is very sensitive to water vapor and oxygen, and in order to resist the invasion of water and oxygen to the display panel and avoid the display panel from having abnormal functions, a first insulating layer 3 is manufactured on the substrate and is used as a water and oxygen blocking layer; specifically, a first insulating layer 3 is formed on a flexible substrate layer by Chemical Vapor Deposition (CVD) or Physical Vapor Deposition (PVD), and the structure is as shown in fig. 2. The material of the first insulating layer 3 is, for example, silicon oxide (SiOx), silicon nitride (SiNx), aluminum oxide (Al2O3), titanium oxide (TiO2), or the like. The first insulating layer has the functions of blocking water and oxygen, so that other inner film layers of the display panel are not contacted with components such as water vapor, oxygen and the like in the atmosphere, and better stability is kept.

The first insulating layer is broken and destroyed due to its own brittleness, that is, the first insulating layer with high brittleness is deformed only slightly under external force (such as stretching, impact, etc.), and in order to solve the problem of high brittleness of the first insulating layer, the ductile layer 4 is formed on the first insulating layer. Specifically, a thin film structure (flexible layer) having high flexibility is formed by Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), evaporation, inkjet printing, or coating, and the like, and the structure is shown in fig. 3. The flexible layer 4 is made of an organic insulating material, such as a polymer material (e.g., PET, PEN, PI, etc.), an organic photosensitive material, graphene, carbon nanotubes, nano silicon oxide (SiOx), silicon nitride (SiNx), etc., which have similar characteristics. The toughness of the toughness layer 4 is greater than the toughness of the first insulating layer 3 and the toughness of the second insulating layer 5. The toughness layer in the technical scheme has better toughness, can play a role in buffering external force and offset impact on the insulating layer caused by certain external force. The display panel has the advantages that the integral bending resistance of the display panel can be improved, the insulating layer with high brittleness is prevented from being damaged, and the display effect and the quality of the display panel are prevented from being influenced, so that the display panel has more advantages.

After the tough layer is manufactured, an insulating layer (a second insulating layer 5) is manufactured on the tough layer to prevent the tough layer from influencing other internal film layers (such as a metal layer). Specifically, a second insulating layer is formed on the ductile layer by Chemical Vapor Deposition (CVD) or Physical Vapor Deposition (PVD), and the second insulating layer covers the ductile layer 4, and the structure is shown in fig. 4. The material of the second insulating layer is, for example, silicon oxide (SiOx), silicon nitride (SiNx), aluminum oxide (Al2O3), titanium oxide (TiO2), or the like. Note that the material and the manufacturing process of the second insulating layer are the same as those of the first insulating layer on the lower surface of the flexible layer 4, and the second insulating layer is substantially the same insulating layer. The first insulating layer, the toughness layer and the second insulating layer form an insulating layer with a sandwich structure, so that the first insulating layer with high brittleness can be prevented from being damaged, and the integral bending resistance of the display panel is improved.

It should be noted that the reason why a flexible layer is provided in an insulating layer and the flexible layer is not directly replaced with an original insulating layer is that the conventional insulating layer has low flexibility but good insulating properties, and the TFT device maintains good performance by using the conventional insulating layers (such as silicon oxide (SiOx), silicon nitride (SiNx), aluminum oxide (Al2O3), titanium oxide (TiO2), and the like). The toughness of the toughness layer is greater than that of the insulating layer, but the toughness layer directly serves as the insulating layer to affect the TFT, and at present, no material capable of being produced in mass production has high toughness and meets the electrical property requirement of the TFT device.

In the first embodiment, the interlayer structure insulating layer is a single-layer whole-surface type interlayer structure, and preferably, the single-layer whole-surface type interlayer structure covers a whole surface of the first insulating layer, i.e. the area of the flexible layer is the same as the area of the first insulating layer, and the structure is as shown in fig. 3. In the second embodiment, the interlayer structure insulating layer may also be a single-layer spacer interlayer structure, that is, the flexible layer includes a plurality of flexible blocks with spaces therebetween, and the structure is as shown in fig. 5. The single-layer interval type sandwich structure also covers the whole first insulating layer, namely the area of the plurality of flexible blocks is close to the area of the first insulating layer. The single-layer spacer sandwich structure in the second embodiment can be manufactured by inkjet printing technology, development and etching technology or nanoimprint technology, and the development and etching technology is taken as an example to be described here: after a film structure (toughness layer) with high toughness is formed by using the technologies of Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), evaporation, ink-jet printing or coating and the like, a layer of photoresist is coated on the toughness layer, and the photoresist is patterned, namely, the part of the toughness layer to be removed is opened by exposure and development. Then, the photoresist is used as a mask to etch the flexible layer at the position where the flexible layer is to be removed, so as to form a plurality of flexible blocks (single-layer interval type sandwich structure) on the first insulating layer, where the position where the flexible layer is to be removed is an interval part between the plurality of flexible blocks, and the structure is shown in fig. 5. Wherein, the cross section shape of the flexible layer (or flexible block) can be round, rectangle, polygon, arc, triangle, etc. After the plurality of toughness blocks are manufactured, the photoresist is removed, and then a second insulating layer is covered on the toughness layer, wherein the structure is shown in fig. 6. The nano-imprinting technique is described as an example: similarly, a layer of photoresist required by a nanoimprint technology is coated on the tough layer, the photoresist is subjected to die pressing by using a mask plate, the photoresist at the position of the tough layer to be removed is removed after demoulding, the tough layer at the position of the tough layer to be removed is removed by etching to form a plurality of tough layers, and finally the photoresist is removed.

Alternatively, in the third embodiment, the interlayer structure is an insulating layer such as a multi-layer spacer interlayer structure, and the flexible layer and the insulating layer are repeatedly formed on the second insulating layer, so that the flexible layer is multi-layered, and the multi-layer spacer interlayer structure is a structure of the first insulating layer-the flexible layer-the second insulating layer, as shown in fig. 7. The flexible layer may be three, four, or even more layers.

After the flexible layer and the second insulating layer covering the flexible layer are formed, a Thin Film Transistor (TFT) and a display device layer of a display panel are formed on the substrate. Thin film transistors such as top gate self-aligned structures, back channel structures, etc. are described herein with reference to TFF for top gate self-aligned structures: an active layer 6 is formed on the second insulating layer 5, and the structure is shown in fig. 8. The active layer 6 is, for example, polysilicon, an oxide semiconductor, graphene, carbon nanotubes, an organic semiconductor, or other materials having similar characteristics. After the active layer 6 is manufactured, a third insulating layer 7 (a gate insulating layer) is manufactured on the active layer 6, and the third insulating layer 7 isolates the contact between the gate 8 (located on the upper surface of the second insulating layer) and the active layer 6, and the structure is as shown in fig. 9. The third insulating layer 7 is located in the middle of the active layer and exposes both sides on the active layer as connection points of the source or drain. The material and manufacturing process of the third insulating layer 7 are the same as those of the first insulating layer, and are described above, so that the detailed description thereof is omitted here. After the third insulating layer 7 is formed, a gate 8 is formed on the third insulating layer 7, and the structure is shown in fig. 10. The gate material, such as one or more of aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and other metals with good conductivity, and alloys thereof, can be plated by evaporation or sputtering. Preferably, the gate electrode 8 is located in the region of the third insulating layer, not in contact with the active layer. When the gate is manufactured, a first electrode plate is also formed on the second insulating layer on one side of the active layer to serve as a lower electrode plate of the capacitor, and the structure is as shown in fig. 10. After the gate is manufactured, a fourth insulating layer 9 is manufactured on the gate, and the fourth insulating layer 9 is used for isolating the gate from the display device layer. Similarly, the material and manufacturing process of the fourth insulating layer 9 are the same as those of the first insulating layer. The fourth insulating layer 9 also covers the first electrode plate, and the third insulating layer in the first electrode plate area is used as a dielectric layer of the capacitor, and the structure is shown in fig. 11. After the fourth insulating layer is manufactured, a through hole communicated with a source-drain connection point on the active layer can be manufactured on the fourth insulating layer 9, and a through hole communicated with the first electrode plate can be also manufactured on the fourth insulating layer 9 to be used as a connection point of the TFT and the capacitor, and the structure is shown in fig. 11. After the fourth insulating layer and the through holes are formed, the source electrode 10 and the drain electrode 11 are formed on the fourth insulating layer. The source and drain electrode material can be plated by evaporation or sputtering, and the source and drain electrode material can be one or more of metals with excellent conductivity, such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium and the like, and alloys. The source electrode 10 and the drain electrode 11 are connected to the active layer 6 through via holes in the fourth insulating layer 9 at source-drain connection points, respectively. One of the source electrode (or the drain electrode) is also connected with the first polar plate through a through hole on the first polar plate through the fourth insulating layer 9, thereby playing a role in connecting the TFT with the capacitor, and the structure is shown in fig. 12. And simultaneously manufacturing a source electrode and a drain electrode, manufacturing a second electrode plate on the fourth insulating layer in the first electrode plate area, wherein the second electrode plate is used as an upper electrode plate of the capacitor, and the structure is shown in fig. 12. So far, the source electrode, the drain electrode, the grid electrode and the active layer (or part of the third insulating layer and the fourth insulating layer) are used as components of the TFT, and the first electrode plate, the second electrode plate and the fourth insulating layer between the first electrode plate and the second electrode plate form a capacitor. In some embodiments, the capacitor may not need to be fabricated.

A plurality of TFTs may also be fabricated on the second insulating layer, and a connection may be made between the source (or drain) and the gate between two TFTs.

The above is a TFT of a top-gate self-aligned structure, and a TFT of a back-channel structure is briefly described here: the back channel structure TFT includes, from bottom to top, a gate electrode, a third insulating layer (i.e., a gate insulating layer), an active layer, a source electrode, and a drain electrode. The source electrode 10 and the drain electrode 11 are directly connected with both sides of the active layer 6 on the upper surface of the active layer, and the active layer 6 is located on the upper surface of the third insulating layer above the gate electrode 8, and the structure is shown in fig. 13. Similarly, the first electrode plate of the capacitor and the grid electrode are manufactured in the same process, the second electrode plate of the capacitor and the source drain electrode are manufactured in the same process, and the third insulating layer between the first electrode plate of the capacitor and the source drain electrode serves as a dielectric layer. Alternatively, an etching barrier layer (corresponding to the fourth insulating layer) may be further formed on the active layer, and then the source and the drain electrodes may be formed on the etching barrier layer, and the source and the drain electrodes may be connected to the active layer.

After the TFT is manufactured, the display device layer including the fifth insulating layer 12, the sixth insulating layer 13, the anode 14, the seventh insulating layer 15, the organic light emitting layer 16, the cathode 17, and the like may be manufactured. For example, a fifth insulating layer 12 (passivation layer) is formed on the TFT to protect the TFT from direct contact with other structures, as shown in fig. 14. The fifth insulating layer 12 covers the TFTs (source, drain, and third insulating layers), and the material and manufacturing process of the fifth insulating layer are the same as those of the first insulating layer, which is described above, so that the details are not repeated here. Generally, the flexible layer and the second insulating layer can be further formed on the fifth insulating layer to form a sandwich insulating layer (the fifth insulating layer-the flexible layer-the second insulating layer) to enhance the flexibility of the fifth insulating layer, so that the display panel is not bent under a large external force. The flexible layer and the second insulating layer can be formed on the first insulating layer, the third insulating layer, the fifth insulating layer, the sixth insulating layer, and the seventh insulating layer of the display panel to form an insulating layer with a sandwich structure.

The fifth insulating layer 12 generally serves as a passivation layer to protect the TFT, and a sixth insulating layer 13 (planarization layer) is formed on the fifth insulating layer 12 to fill in the unevenness of the substrate caused by a plurality of processes. The sixth insulating layer 13 covers the fifth insulating layer 12, and the sixth insulating layer 13 has a certain thickness, so that the sixth insulating layer 13 can fill up different recesses on the plurality of substrates, and the structure is shown in fig. 15. The material and the manufacturing process of the sixth insulating layer, the material and the manufacturing process of the fifth insulating layer are the same as those of the first insulating layer. Or in some embodiments, may act as a sixth insulating layer by increasing the thickness of the fifth insulating layer.

After the fifth insulating layer and the sixth insulating layer are manufactured, a through hole communicated with a drain electrode (or a source electrode) of the TFT is manufactured on the sixth insulating layer, so that the subsequent anode 14 is connected with the TFT. Specifically, a photoresist is coated on the sixth insulating layer, and the photoresist is patterned, i.e., exposed and developed, so as to open the portion where the through hole is to be formed. Then, the sixth insulating layer is etched to the upper surface of the drain electrode by using the photoresist as a mask, so as to form a via hole, and the structure is shown in fig. 15. The through hole penetrates through the sixth insulating layer and the fifth insulating layer of the drain region, and the photoresist is removed after the through hole is manufactured. Alternatively, after the fifth insulating layer is formed, through holes may be formed in the fifth insulating layer, a sixth insulating layer may be formed on the fifth insulating layer, and through holes may be formed in the sixth insulating layer to communicate with the drain (or the source).

An anode 14 is formed on the sixth insulating layer, the anode 14 is connected to the drain electrode 11 through a through hole in the sixth insulating layer 13, and the anode has a portion outside the through hole, and the structure is shown in fig. 16. Or in some cases the anode may be connected to the source (not to the drain). An anode such as one or more metals of high reflectivity Al (aluminum), Ag (silver), Au (gold), Indium tin oxide (ITO for short). Preferably, the upper part of the anode is made of ITO, so that the anode has better reflectivity and conductivity. After the anode is fabricated, a seventh insulating layer 15 (pixel defining layer) is fabricated on the sixth insulating layer 13, and the material and fabrication process of the seventh insulating layer 15 are the same as those of the first insulating layer, and the structure is shown in fig. 17. The seventh insulating layer 15 covers the anode 14, and then a through hole is formed in the seventh insulating layer 15 on the anode, wherein the through hole is used for connecting the anode and the organic light emitting layer, and the structure is shown in fig. 17. Preferably, the anode at the bottom of the through hole on the seventh insulating layer is located outside the through hole on the sixth insulating layer, that is, the anode at the bottom of the through hole on the seventh insulating layer is horizontal to the substrate direction. Then, an organic light emitting layer 16 is formed at the through hole on the seventh insulating layer 15, and the organic light emitting layer 16 is connected to the anode 14 through the through hole on the seventh insulating layer 15, as shown in fig. 18. The organic light emitting layer 16 includes a hole injection layer HIL, a hole transport layer HTL, an organic light emitting layer EM, an electron transport layer ETL, and an electron injection layer EIL. The organic light emitting layer can be prepared by evaporation or sputtering. After the organic light emitting layer is manufactured, a transparent cathode 17 is manufactured on the organic light emitting layer 16, the cathode 17 covers the organic light emitting layer, and the cathode 17 may also cover a seventh insulating layer, and the structure is shown in fig. 19. The cathode can be made by evaporation or sputtering, and the cathode is made of materials with similar characteristics, such as magnesium-silver alloy and the like.

After the cathode is fabricated, a packaging process is performed, such as disposing a flexible cover 18, a single layer film or a multi-layer film on the cathode, and the structure is shown in fig. 20 (shown as a flexible cover). Finally, the substrate 1 may be separated and the rest of the process of the display panel may be performed, as shown in fig. 21.

The present embodiment provides a display panel with a sandwich structure, which is manufactured by the method for manufacturing a display panel with a sandwich structure according to any one of the foregoing embodiments. A flexible substrate layer 2 is arranged on a substrate 1, so that the substrate 1 forms a flexible substrate, and the structure is shown in fig. 1. The flexible substrate layer 2 is made of Polyethylene terephthalate (abbreviated PET), Polyethylene naphthalate (abbreviated PEN), Polyimide (abbreviated PI), or other materials having similar properties. The flexible substrate layer 2 is light in weight and good in flexibility effect, and can endow the flexible substrate with great advantages. A first insulating layer 3 is disposed on the flexible substrate layer 2, and a material of the first insulating layer 3 is silicon oxide (SiOx), silicon nitride (SiNx), aluminum oxide (Al2O3), titanium oxide (TiO2), or the like. The first insulating layer has the functions of blocking water and oxygen, so that other inner film layers of the display panel are not contacted with components such as water vapor, oxygen and the like in the atmosphere, and better stability is kept.

The first insulating layer is broken and damaged due to the fact that the first insulating layer is relatively brittle, namely, the first insulating layer with relatively high brittleness is subjected to small deformation under the action of external force (such as stretching, impact and the like), and in order to solve the problem that the first insulating layer is relatively brittle, a toughness layer 4 is arranged in the first insulating layer. The flexible layer 4 is an organic insulating material, such as a polymer material (e.g., PET, PEN, PI, etc.), an organic photosensitive material, graphene, carbon nanotubes, nano silicon oxide (SiOx), silicon nitride (SiNx), etc., which have similar characteristics. The toughness of the ductile layer 4 is greater than the toughness of the first insulating layer. The toughness layer in the technical scheme has better toughness, can play a role in buffering external force and offset impact on the insulating layer caused by certain external force. The display panel has the advantages that the integral bending resistance of the display panel can be improved, the insulating layer with high brittleness is prevented from being damaged, and the display effect and the quality of the display panel are prevented from being influenced, so that the display panel has more advantages.

In the first embodiment, the interlayer structure insulating layer is a single-layer whole-surface type interlayer structure, and preferably, the single-layer whole-surface type interlayer structure covers a whole surface of the first insulating layer, i.e. the area of the flexible layer is the same as the area of the first insulating layer, and the structure is as shown in fig. 3. In the second embodiment, the interlayer structure insulating layer may also be a single-layer spacer interlayer structure, that is, the flexible layer includes a plurality of flexible blocks with spaces therebetween, and the structure is as shown in fig. 5 and 6. The single-layer interval type sandwich structure also covers the whole first insulating layer, namely the area of the plurality of flexible blocks is close to the area of the first insulating layer. Wherein, the cross section shape of the flexible layer (or flexible block) can be round, rectangle, polygon, arc, triangle, etc. Or in the third embodiment, the sandwich structure insulating layer is a multi-layer interval type sandwich structure, and a plurality of layers of the flexible layers are stacked on top of each other and have intervals, and the structure is shown in fig. 7. For process reasons, the insulating layer overlying the ductile layer is referred to herein as the second insulating layer 5, and the second insulating layer 5 is essentially the same as the first insulating layer.

It should be noted that the reason why a flexible layer is provided in the insulating layer and the flexible layer is not directly replaced with the original insulating layer is that the conventional insulating layer has low flexibility but good insulating properties, and the TFT device maintains good performance by using the conventional insulating layers (such as silicon oxide (SiOx), silicon nitride (SiNx), aluminum oxide (Al2O3), titanium oxide (TiO2), and the like). The toughness of the toughness layer is greater than that of the insulating layer, but the toughness layer directly serves as the insulating layer to affect the TFT, and at present, no material capable of being produced in mass production has high toughness and meets the electrical property requirement of the TFT device.

A Thin Film Transistor (TFT) of a display panel and a display device layer are provided on the second insulating layer 5. Thin film transistors such as top gate self-aligned structures, back channel structures, etc. are described herein with reference to TFF for top gate self-aligned structures: an active layer 6 is provided on the second insulating layer 5, and the structure is shown in fig. 8. The active layer 6 is, for example, polysilicon, an oxide semiconductor, graphene, carbon nanotubes, an organic semiconductor, or other materials having similar characteristics. A third insulating layer 7 (gate insulating layer) is provided on the active layer 6, and the third insulating layer 7 serves to isolate the contact between the gate 8 (located on the upper surface of the second insulating layer) and the active layer 6, and the structure is shown in fig. 9. The third insulating layer 7 is located in the middle of the active layer and exposes two sides on the active layer to be used as source and drain connection points. The material of the third insulating layer 7 is the same as that of the first insulating layer, which has been described above, and therefore, the description thereof is omitted here. A gate electrode 8 is provided on the third insulating layer 7, and the structure is shown in fig. 10. Gate materials such as one or more of metals having excellent conductivity, such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and alloys thereof. Preferably, the gate electrode 8 is located in the region of the third insulating layer, not in contact with the active layer. A first electrode plate is also arranged on the second insulating layer on one side of the active layer and is used as a lower electrode plate of the capacitor, and the structure is shown in fig. 10. A fourth insulating layer 9 is provided over the gate electrode, the fourth insulating layer 9 serving to isolate the gate electrode from the display device layers. Similarly, the material of the fourth insulating layer 9 is the same as that of the first insulating layer. The fourth insulating layer 9 also covers the first electrode plate, and the third insulating layer in the first electrode plate area is used as a dielectric layer of the capacitor, and the structure is shown in fig. 11. A through hole communicating with a source or drain connection point on the active layer is provided in the fourth insulating layer 9, and a through hole communicating with the first electrode plate is provided in the fourth insulating layer 9 as a connection point between the TFT and the capacitor, and the structure is as shown in fig. 11. A source electrode 10 and a drain electrode 11 are provided on the fourth insulating layer, and a source-drain electrode material such as one or more of metals having excellent conductivity, such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and the like, and alloys thereof. The source electrode 10 and the drain electrode 11 are connected to the active layer 6 through via holes in the fourth insulating layer 9 at source-drain connection points, respectively. One of the source electrode (or the drain electrode) is also connected with the first polar plate through a through hole on the first polar plate through the fourth insulating layer 9, thereby playing a role in connecting the TFT with the capacitor, and the structure is shown in fig. 12. A second electrode plate is arranged on the fourth insulating layer in the first electrode plate area, and the second electrode plate is used as an upper electrode plate of the capacitor, and the structure is shown in fig. 12. So far, the source electrode, the drain electrode, the grid electrode and the active layer (or part of the second insulating layer and the fourth insulating layer) are used as components of the TFT, and the first electrode plate, the second electrode plate and the fourth insulating layer between the first electrode plate and the second electrode plate form a capacitor. In some embodiments, a capacitor may not be required. In some embodiments, there are a plurality of TFTs, and a connection between a source (or drain) and a gate between two TFTs may be formed.

The above is a TFT of a top-gate self-aligned structure, and a TFT of a back-channel structure is briefly described here: the back channel structure TFT includes, from bottom to top, a gate electrode, a third insulating layer (i.e., a gate insulating layer), an active layer, a source electrode, and a drain electrode. The source electrode 10 and the drain electrode 11 are directly connected with both sides of the active layer 6 on the upper surface of the active layer, and the active layer 6 is located on the upper surface of the third insulating layer above the gate electrode 8, and the structure is shown in fig. 13. Similarly, the first electrode plate of the capacitor and the grid electrode are positioned on the same plane, the second electrode plate of the capacitor and the source and drain electrodes are positioned on the same plane, and the third insulating layer between the first electrode plate and the source and drain electrodes is used as a dielectric layer. Alternatively, an etching stopper layer (corresponding to a fourth insulating layer) may be disposed on the active layer, and then a source electrode and a drain electrode may be disposed on the etching stopper layer, and the source electrode and the drain electrode may be connected to the active layer.

The display device layer includes a fifth insulating layer 12, a sixth insulating layer 13, an anode 14, a seventh insulating layer 15, an organic light emitting layer 16, a cathode 17, and the like. For example, a fifth insulating layer 12 (passivation layer) is provided on the TFT for protecting the TFT from direct contact with other structures, as shown in fig. 14. The fifth insulating layer 12 covers the TFTs (source, drain, and third insulating layers), and the material of the fifth insulating layer is the same as that of the first insulating layer, which is described above, so that the description thereof is omitted here. Generally, a flexible layer may also be disposed in the fifth insulating layer to enhance the flexibility of the fifth insulating layer, so that the display panel is not bent when subjected to a large external force. The flexible layer may be provided in each of the first insulating layer, the third insulating layer, the fourth insulating layer, the fifth insulating layer, the sixth insulating layer, and the seventh insulating layer of the display panel.

The fifth insulating layer 12 generally serves as a passivation layer to protect the TFT, and a sixth insulating layer 13 (planarization layer) is disposed on the fifth insulating layer 12 to fill in the unevenness of the substrate caused by a plurality of processes. The sixth insulating layer 13 covers the fifth insulating layer 12, and the sixth insulating layer 13 has a certain thickness, so that the sixth insulating layer 13 can fill up different recesses on the plurality of substrates, and the structure is shown in fig. 15. The material of the sixth insulating layer is the same as the material of the fifth insulating layer. Or in some embodiments, may act as a sixth insulating layer by increasing the thickness of the fifth insulating layer.

A via hole communicating with a drain (or source) of the TFT is provided on the sixth insulating layer so that the subsequent anode 14 is connected to the TFT. The via penetrates the sixth insulating layer and the fifth insulating layer of the drain region.

An anode 14 is disposed on the sixth insulating layer, the anode 14 is connected to the drain electrode 11 through a through hole in the sixth insulating layer 13, and the anode has a portion outside the through hole, and the structure is shown in fig. 16. Or in some cases the anode may be connected to the source (not to the drain). An anode such as one or more metals of high reflectivity Al (aluminum), Ag (silver), Au (gold), Indium tin oxide (ITO for short). Preferably, the upper part of the anode is made of ITO, so that the anode has better reflectivity and conductivity. A seventh insulating layer 15 (pixel defining layer) is disposed on the sixth insulating layer 13, and the material of the seventh insulating layer 15 is the same as that of the first insulating layer, and the structure is shown in fig. 17. The seventh insulating layer 15 covers the anode 14, and then a through hole is formed at the seventh insulating layer 15 on the anode, and the through hole is used for connecting the anode and the organic light emitting layer, and the structure is shown in fig. 17. Preferably, the anode at the bottom of the through hole on the seventh insulating layer is located outside the through hole on the sixth insulating layer, that is, the anode at the bottom of the through hole on the seventh insulating layer is horizontal to the substrate direction. Then, an organic light emitting layer 16 is disposed at the through hole on the seventh insulating layer 15, and the organic light emitting layer 16 is connected to the anode 14 through the through hole on the seventh insulating layer 15, as shown in fig. 18. The organic light emitting layer 16 includes a hole injection layer HIL, a hole transport layer HTL, an organic light emitting layer EM, an electron transport layer ETL, and an electron injection layer EIL. A transparent cathode 17 is disposed on the organic light emitting layer 16, the cathode 17 covers the organic light emitting layer, and the cathode 17 may further cover a seventh insulating layer, and the structure is shown in fig. 19.

Finally, a flexible cover 18, a single layer film or a multilayer film is disposed on the cathode, as shown in fig. 20 (shown as a flexible cover). The substrate 1 is then separated and the structure is shown in figure 21.

It should be noted that, although the above embodiments have been described herein, the scope of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, the changes and modifications of the embodiments described herein, or the equivalent structure or equivalent process changes made by the contents of the specification and the drawings of the present invention, directly or indirectly apply the above technical solutions to other related technical fields, all included in the scope of the present invention.

Claims (4)

1. The display panel with the sandwich structure is characterized by comprising an insulating layer, wherein a toughness layer is arranged in the insulating layer, and the toughness of the toughness layer is greater than that of the insulating layer.

2. The display panel with a sandwich structure according to claim 1, wherein the flexible layer is a plurality of flexible blocks, and a plurality of the flexible blocks have a space therebetween; or:

the toughness layer is the multilayer, and the multilayer toughness layer stacks on top of each other and has the interval.

3. The display panel with a sandwich structure according to claim 1, wherein the flexible layer is an organic insulating material.

4. The display panel with a sandwich structure according to claim 1, further comprising a TFT and a display device layer;

the TFT is arranged on the insulating layer;

the display device layer is arranged on the TFT, and an anode of the display device layer is connected with a source electrode or a drain electrode of the TFT.

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