CN109273505B

CN109273505B - Display device, flexible O L ED display panel and manufacturing method thereof

Info

Publication number: CN109273505B
Application number: CN201811141110.4A
Authority: CN
Inventors: 孙远生; 赵恩霆; 张向伟; 郑红
Original assignee: Bazhou Yungu Electronic Technology Co ltd
Current assignee: Bazhou Yungu Electronic Technology Co ltd
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-08-04
Anticipated expiration: 2038-09-28
Also published as: CN109273505A

Abstract

The invention provides a display device, a flexible O L ED display panel and a manufacturing method thereof, wherein a concave-convex fluctuant organic soft layer is manufactured by utilizing a concave-convex uneven structure of a plurality of first deep grooves in a solid flexible substrate, and an air gap is formed between the organic soft layer and an inorganic material layer on the organic soft layer.

Description

Display device, flexible O L ED display panel and manufacturing method thereof

Technical Field

The invention relates to the technical field of O L ED display equipment, in particular to a display device, a flexible O L ED display panel and a manufacturing method thereof.

Background

The O L ED has low power consumption and good display brightness compared with other display devices due to its self-luminous characteristics, and the O L ED display prepared on the flexible substrate is also easier to realize bendable display with smaller bending radius.

However, in the conventional O L ED display panel, since the inorganic material layer is provided, for example, the array pixel circuit TFT for driving the O L ED pixel is formed by using an inorganic material, the stress of the inorganic material layer is large, so that the O L ED display panel is prone to inorganic layer fracture or peeling of the functional layer of the O L ED pixel during the bending process.

In view of the above, the present invention provides a new display device, a flexible O L ED display panel and a method for manufacturing a flexible O L ED display panel, which improve the bending performance of a flexible substrate to solve the above technical problems.

Disclosure of Invention

The invention aims to provide a display device, a flexible O L ED display panel and a manufacturing method of the flexible O L ED display panel, which are used for improving the stress buffering of an inorganic stress layer in the bending process of the O L ED display panel and improving the reliability of the O L ED display panel.

To achieve the above object, a first aspect of the present invention provides a flexible O L ED display panel, comprising:

a solid flexible substrate having a plurality of first deep grooves;

the organic soft layer covers the bottom wall and the side wall of the first deep groove and the solid flexible substrate outside the first deep groove; the organic soft layer does not fill the first deep groove; the first deep groove covered with the organic soft layer becomes a second deep groove;

the inorganic material layer is positioned on the organic soft layer, seals the second deep groove and forms a first air gap in the second deep groove; the upper surface of the inorganic material layer is flat and comprises a central area and an edge area surrounding the central area;

an O L ED light emitting device located in the central region of the upper surface of the inorganic material layer;

an inorganic material layer located on the edge region and an encapsulation layer located on the O L ED light emitting device of the central region.

Optionally, the solid flexible substrate includes a first sublayer and a second sublayer stacked from bottom to top, and the first deep groove is located in the second sublayer.

Optionally, the first sub-layer and the second sub-layer are made of the same material and are made of polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide.

Optionally, the first sub-layer and the second sub-layer are made of different materials, and the first sub-layer is made of polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide; the second sub-layer is made of polyimide, polymethyl methacrylate, polymethyl glutarimide or phenolic resin.

Optionally, the first deep groove and the second deep groove are holes or grooves.

Optionally, the aspect ratio of the second deep groove is greater than 5: 1.

optionally, the material of the organic soft layer is polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide.

Optionally, the inorganic material layer is made of silicon nitride, silicon oxide, or silicon oxynitride.

Optionally, the package further comprises a touch layer located on the encapsulation layer.

A second aspect of the invention provides a display device comprising a flexible O L ED display panel according to any one of the above.

The third aspect of the present invention provides a method for manufacturing a flexible O L ED display panel, comprising:

providing a solid flexible substrate, and forming a plurality of first deep grooves in the solid flexible substrate;

covering an organic soft layer on the bottom wall and the side wall of the first deep groove and the solid flexible substrate outside the first deep groove; the organic soft layer does not fill the first deep groove; the first deep groove covered with the organic soft layer becomes a second deep groove;

depositing an inorganic material layer on the organic soft layer, sealing the second deep groove by depositing the inorganic material layer, and forming a first air gap in the second deep groove;

performing chemical mechanical polishing planarization on the upper surface of the inorganic material layer, wherein the upper surface comprises a central area and an edge area surrounding the central area;

forming an O L ED light emitting device in a central region of an upper surface of the planarized inorganic material layer;

an encapsulation layer is formed on the inorganic material layer of the edge region and the O L ED light emitting device of the center region.

Optionally, the solid flexible substrate includes a first sublayer and a second sublayer stacked from bottom to top, and the first deep groove is formed in the second sublayer.

Optionally, the first sub-layer and the second sub-layer are made of the same material and are made of polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide; the first deep groove is formed by a nano-imprinting method.

Optionally, the first sub-layer and the second sub-layer are made of different materials, and the first sub-layer is made of polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide; the second sub-layer is made of polyimide, polymethyl methacrylate, polymethyl glutarimide or phenolic resin; the first deep groove is formed by adopting a photoetching method.

Optionally, the aspect ratio of the second deep groove is greater than 5: 1.

optionally, covering the organic soft layer is achieved using evaporated polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone, or polyetherimide.

Optionally, the inorganic material layer is made of silicon nitride, silicon oxide, or silicon oxynitride, and the corresponding deposition method is a chemical vapor deposition method.

Optionally, a touch layer is manufactured on the packaging layer.

A fourth aspect of the present invention provides a flexible O L ED display panel, comprising:

a solid flexible substrate;

an inorganic material layer on the solid flexible substrate, an upper surface of the inorganic material layer including a central region and a peripheral region surrounding the central region;

the packaging layer is positioned on the inorganic material layer of the edge area and the O L ED light-emitting device of the central area, and comprises a first inorganic material packaging layer, an organic soft layer and a second inorganic material packaging layer from bottom to top;

wherein: the first inorganic material packaging layer is provided with a plurality of third deep grooves;

the organic soft layer covers the bottom wall and the side wall of the third deep groove and the first inorganic material packaging layer outside the third deep groove; the organic soft layer does not fill the third deep groove; the third deep groove covered with the organic soft layer becomes a fourth deep groove;

and the second inorganic material packaging layer seals the fourth deep groove and forms a second air gap in the fourth deep groove.

Optionally, the first inorganic material encapsulation layer and the second inorganic material encapsulation layer are made of silicon nitride.

Optionally, the third deep groove and the fourth deep groove are holes or grooves.

Optionally, the third deep groove has a large opening and a small bottom.

Optionally, the aspect ratio of the fourth deep groove is greater than 5: 1.

A fifth aspect of the present invention provides a display device comprising the flexible O L ED display panel of any one of the above fourth aspects.

A sixth aspect of the present invention provides a method for manufacturing a flexible O L ED display panel, including:

providing a solid flexible substrate;

forming an inorganic material layer on the solid flexible substrate, wherein the upper surface of the inorganic material layer comprises a central area and an edge area surrounding the central area;

forming an O L ED light emitting device in a central region of an upper surface of the inorganic material layer;

forming an encapsulation layer on the inorganic material layer of the edge region and the O L ED light emitting device of the central region;

wherein forming the encapsulation layer comprises:

depositing a first inorganic material encapsulation layer on the inorganic material layer of the edge region and the O L ED light emitting device of the central region, forming a plurality of third deep grooves on the first inorganic material encapsulation layer;

covering an organic soft layer on the bottom wall and the side wall of the third deep groove and the first inorganic material packaging layer outside the third deep groove; the organic soft layer does not fill the third deep groove; the third deep groove covered with the organic soft layer becomes a fourth deep groove;

and depositing a second inorganic material packaging layer on the organic soft layer, sealing the fourth deep groove by depositing the second inorganic material packaging layer, and forming a second air gap in the fourth deep groove.

Optionally, the third deep groove is formed by photolithography and dry etching.

Optionally, the third deep groove formed by photolithography and dry etching is a hole or a trench.

Optionally, before covering the organic soft layer, expanding an opening of the third deep groove.

Optionally, the aspect ratio of the fourth deep groove is greater than 5: 1.

Optionally, the first inorganic material encapsulation layer and the second inorganic material encapsulation layer are made of silicon nitride, and the corresponding deposition method is a chemical vapor deposition method.

Optionally, a touch layer is manufactured on the packaging layer.

Compared with the prior art, the invention has the beneficial effects that:

1) the invention utilizes the rugged structure of a plurality of first deep grooves in the solid flexible substrate to manufacture a rugged organic soft layer, and an air gap (airgap) is formed between the organic soft layer and the inorganic material layer on the organic soft layer.

2) The first deep groove does not penetrate through the solid flexible substrate. In the alternative, the solid flexible substrate may include a first sublayer and a second sublayer stacked from bottom to top; the two materials may be a) the same or b) different. For the embodiment a), the materials of the two substrates can be conventional solid flexible substrate materials such as polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide. The first sub-layer may be cured first, and then the protrusions of the nano-imprint template may be pressed against the surface of the solid first sub-layer to cure the liquid second sub-layer.

For the first sub-layer in the scheme b), the material may be a conventional solid flexible substrate material such as polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide. The second sub-layer is made of photosensitive materials such as polyimide, polymethyl methacrylate, polymethyl glutarimide or phenolic resin, and thus, a first deep groove can be formed in the second sub-layer by utilizing a photoetching method.

Regardless of the a) scheme or the b) scheme, the process of forming the first deep groove in the second sublayer is easily controlled relative to the process of forming the deep groove in a partial thickness of the solid flexible substrate.

3) In the case of a groove, the extending direction of the groove is perpendicular to the curling direction of the O L ED display panel.

4) In an alternative, the Aspect Ratio (Aspect Ratio) of the second deep groove is greater than 5: 1. therefore, when the inorganic material layer is deposited, the inorganic material can close the second deep groove to form an air gap.

5) In the alternative, the material of the organic soft layer may be polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide. Therefore, the evaporation plating of the materials can be adopted to form a thin organic soft layer on the bottom wall, the side wall and the surface of the solid flexible substrate outside the groove of the first deep groove, so that the first deep groove is not filled, and the depth-to-width ratio of the first deep groove is not greatly reduced.

6) In an alternative, the inorganic material layer is made of silicon nitride, silicon oxide, or silicon oxynitride. The materials can be formed by adopting a chemical vapor deposition method, and macromolecules generated by chemical reaction are easy to stack at the edge of the opening of the second deep groove and are easy to seal.

Drawings

FIG. 1 is a schematic structural diagram of a flexible O L ED display panel according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a flexible O L ED display panel according to another embodiment of the present invention;

FIG. 3 is a flow chart of a method for manufacturing a flexible O L ED display panel according to an embodiment of the invention;

FIGS. 4 to 9 are intermediate structural views of the flow of FIG. 3;

FIG. 10 is a schematic diagram of a flexible O L ED display panel according to yet another embodiment of the invention;

FIG. 11 is a schematic diagram of a flexible O L ED display panel according to yet another embodiment of the present invention;

FIG. 12 is a flow chart of a method of fabricating a flexible O L ED display panel in accordance with a further embodiment of the invention;

fig. 13 to 15 are intermediate structural views of the flow of fig. 12.

To facilitate an understanding of the invention, all reference numerals appearing in the invention are listed below:

flexible O L ED display panels 1, 1', 3' solid state

flexible substrates

11, 11', 31

The first deep groove 111 organic

soft layer

12, 342

Second deep recesses 13 inorganic material layers 14, 32

The first air gap 15 has a central region A

Edge region B O L ED

light emitting device

16, 33

Encapsulation layer

17, 34 second sub-layer 113

First sub-layer 112 imprint template 2

The bump 21 first inorganic material encapsulation layer 341

Second inorganic Material encapsulation layer 343 third deep recesses 3411, 3411'

Fourth deep groove 35 second air gap 36

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Fig. 1 is a schematic structural diagram of a flexible O L ED display panel according to an embodiment of the present invention.

Referring to fig. 1, the flexible O L ED display panel 1 includes:

a solid flexible substrate 11, the solid flexible substrate 11 having a plurality of first deep grooves 111;

an organic soft layer 12 covering the bottom wall and the side wall of the first deep groove 111 and the solid-state flexible substrate 11 outside the first deep groove 111; the organic soft layer 12 does not fill the first deep groove 11; the first deep groove 11 covered with the organic soft layer 12 becomes a second deep groove 13;

the inorganic material layer 14 is positioned on the organic soft layer 12, the inorganic material layer 14 seals the second deep groove 13, and a first air gap 15 is formed in the second deep groove 13; the upper surface of the inorganic material layer 14 is flat and includes a central region a and an edge region B surrounding the central region a;

an O L ED light emitting device 16 located at the central region A of the upper surface of the inorganic material layer;

an encapsulation layer 17 on the inorganic material layer 14 of the edge region B and the O L ED light emitting device 16 of the central region a.

The material of the solid flexible substrate 11 may be polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide. The first deep groove 111 does not penetrate the solid flexible substrate 11.

The first deep recesses 111 may be a) holes or b) grooves, in the case of a) each hole may be circular, rectangular, etc. in the case of b) each groove may be a strip-like shape in the case of a top view, and the extending direction of the strip-like shape is perpendicular to the curling direction of the flexible O L ED display panel 1.

The aspect ratio of the first deep groove 111 is preferably greater than 5:1, for example, may be 10: 1.

the material of the organic soft layer 12 may be polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone, or polyetherimide. The material has good flexibility and good buffering performance.

The first deep groove 111 covered with the organic soft layer 12 becomes the second deep groove 13. Since the organic soft layer 12 is thin, the aspect ratio of the second deep groove 13 is substantially equal to the aspect ratio of the first deep groove 111, and is still large. When the inorganic material layer 14 is deposited on the organic soft layer 12, the second deep trench 13 is easily sealed when the inorganic material layer 14 is not deposited in the second deep trench 13 or the deposition amount of the inorganic material layer 14 is small because the reactant molecules for generating the inorganic material are large. The second deep groove 13 after sealing forms a first air gap 15.

The material of the inorganic material layer 14 may be at least one of silicon nitride, silicon oxynitride, and silicon oxide. When the silicon nitride or the silicon oxynitride is used, the silicon nitride or the silicon oxynitride can be used as a passivation layer to prevent external water vapor and oxygen from diffusing upwards from the solid flexible substrate 11. When silicon oxide is used, the silicon oxide can be used as an adhesion layer to improve the adhesion between the solid flexible substrate 11 and the subsequent inorganic material thereon and prevent peeling.

An alternative to the O L ED light emitting device 16 may include an array pixel circuit including a plurality of Thin Film Transistors (TFTs), such as a switching transistor and a driving transistor, and an O L ED pixel, in which a drain of the driving transistor is connected to a pixel electrode of the O L ED pixel, which serves as an anode, for injecting holes, and a cathode of the O L ED pixel is served by a common electrode, and the array pixel circuit and the O L ED pixel operate such that a gate of the switching transistor is electrically connected to a gate line, a source of the switching transistor is connected to a data line, the switching transistor is turned on and supplies an electric signal in the data line to the driving transistor when a scan signal of the gate line is active, the driving transistor is turned on and supplies an electric signal in a power supply voltage signal to the anode of the O L ED pixel, a potential difference is formed between the anode and the cathode, and electrons of the holes of the anode and electrons of the cathode are combined to emit light in an organic light emitting layer, thereby achieving a.

The pixel array circuit and the O L ED pixel can also be implemented by conventional pixel array light emitting units, which is not limited by the invention.

The Encapsulation layer 17 may be each layer of a Thin Film Encapsulation (TFE), such as a three-layer structure of silicon nitride, an organic layer, and silicon nitride. It is also possible to use a stack of several organic, inorganic materials, which the invention is not limited to.

In the flexible O L ED display panel 1, the rugged structure of the first deep grooves 111 in the solid flexible substrate 11 is utilized to manufacture the organic soft layer 12 with rugged structure, and the first air gap 15 is formed between the organic soft layer 12 and the inorganic material layer 14 on the organic soft layer, so that the advantages are that part of the material of the solid flexible substrate 11 is removed when the first deep grooves 111 are manufactured, the bending performance of the solid flexible substrate 11 is improved, the tensile performance of the organic soft layer 12 relative to the inorganic material is good, the stress in the bending process of the O L ED display panel 1 can be buffered, and the first air gap 15 provides a containing space for tensile or compressive strain of the soft material layer 12, and the stress transmission among the layers can not be caused.

The flexible O L ED display panel 1 can be used as a display device, and can be further provided with a touch layer on the packaging layer 17 to serve as a touch panel, the flexible O L ED display panel 1 can be integrated and assembled with other components as a semi-finished product to form a display device such as a mobile phone, a tablet computer (PAD), a vehicle-mounted display screen, and the like, it can be understood that the rugged organic soft layer 12 and the first air gap 15 can also improve the buffering of the solid flexible substrate 11 against stress generated during a touch process.

Fig. 2 is a schematic structural view of a flexible O L ED display panel according to another embodiment of the present invention, referring to fig. 2, a flexible O L ED display panel 1 'in the present embodiment has substantially the same structure as the flexible O L ED display panel 1 in fig. 1 except that a solid flexible substrate 11' includes a first sub-layer 112 and a second sub-layer 113 stacked from bottom to top, and a first deep groove 111 is formed in the second sub-layer 113.

In one embodiment, the first sub-layer 112 and the second sub-layer 113 are made of the same material, and are made of polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide.

In another embodiment, the first sub-layer 112 and the second sub-layer 113 are made of different materials. The first sub-layer 112 is made of polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide; the second sub-layer 113 is made of polyimide, polymethyl methacrylate, polymethyl glutarimide, or phenol resin.

The above arrangement is due to the convenience of manufacturing the first deep groove 111.

For the flexible O L ED display panel 1, 1' described above, the present invention also provides a manufacturing method, fig. 3 is a manufacturing flow chart in an embodiment, and fig. 4 to 9 are intermediate structure diagrams.

The following describes each manufacturing step in detail with reference to fig. 3 to 9.

First, with reference to fig. 3 to 5, step S1 is performed to provide the solid flexible substrate 11, 11', and a plurality of first deep grooves 111 are formed in the solid flexible substrate 11.

In one embodiment, as shown in fig. 4, the solid flexible substrate 11 may be a layer, and the specific material may be polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide. The first deep recesses 111 may be imprinted during curing of the solid flexible substrate 11 using a template 2 having a plurality of protrusions 21. It will be appreciated that the height of the template 2 during imprinting may need to be controlled by additional clamping or suction devices.

In another aspect, as shown in fig. 5, the solid flexible substrate 11' includes a first sublayer 112 and a second sublayer 113 stacked from bottom to top.

In a specific manufacturing process, a) the first sub-layer 112 and the second sub-layer 113 may be made of the same material, and may be made of a conventional solid flexible substrate material such as polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone, or polyetherimide. The first sub-layer 112 may be cured first, and then the protrusions 21 of the nano-imprint template 2 are pressed against the surface of the solid first sub-layer 112, and the liquid second sub-layer 113 is cured by heating; after removing the template 2, the first deep grooves 111 are formed at the occupied places of the protrusions 21 of the template 2.

For the nano-imprint method, the aspect ratio of the protrusion 21 is preferably greater than 5:1, so that the aspect ratio of the formed first deep groove 111 is greater than 5: 1.

In addition to the nanoimprint method in a), b) the first sublayer 112 and the second sublayer 113 may be made of different materials. The material of the first sub-layer 112 may be a conventional solid flexible substrate material such as polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide. The second sub-layer 113 may be made of a photosensitive material such as polyimide, polymethyl methacrylate, polymethyl glutarimide, or phenol resin. The first deep groove 111 is formed by a photolithography method, that is, a mask plate with a hollow pattern or a light-transmitting pattern is used for exposing the second sublayer 113, and then a developing solution is used for developing; the region dissolved by the developing solution forms the first deep groove 111.

If the exposure and development method is used, the ratio of the thickness of the exposed photosensitive material to the planar size of the light-transmissive pattern is preferably greater than 5:1, so that the aspect ratio of the first deep groove 111 is greater than 5: 1.

The following process steps are continued with reference to the structure of fig. 4; the subsequent process steps of the structure in fig. 5 are consistent therewith.

Next, step S2 is executed, referring to fig. 6, the solid flexible substrate 11 outside the bottom wall and the side wall of the first deep groove 111 and the first deep groove is covered with an organic soft layer 12; the organic soft layer 12 does not fill the first deep groove 111; the first deep groove 111 covered with the organic soft layer 12 becomes the second deep groove 13.

In one embodiment, the covering of the organic soft layer 12 may be performed by spin coating liquid polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone, or polyetherimide, and heating and curing. Spin coating is a technique that utilizes a high speed spin to spin off the film, which can be thin.

In another embodiment, the organic soft layer 12 may be covered by a method of depositing an organic material, and the organic soft layer 12 formed by deposition may be thin.

Next, step S3 is executed, and referring to fig. 7, the inorganic material layer 14 is deposited on the organic soft layer 12, the deposited inorganic material layer 14 seals the second deep recess 13, and the first air gap 15 is formed in the second deep recess 13.

The inorganic material layer 14 is made of silicon nitride, silicon oxide, or silicon oxynitride, and the corresponding deposition method is Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD), or Plasma Enhanced Chemical Vapor Deposition (PECVD). The deposition process is carried out in a reaction chamber. For example, for chemical vapor deposition, the molecules of the chemical reactant reacting to form the inorganic material are large, and the reactant can be deposited at the opening of the second deep groove 13 by reducing the vacuum pumping force applied to the reaction chamber.

After the step S3 is completed, referring to fig. 7, the upper surface of the inorganic material layer 14 may be uneven.

Thereafter, step S4 is executed, and referring to fig. 8, the upper surface of the inorganic material layer 14 is planarized by chemical mechanical polishing, where the upper surface includes a central region a and an edge region B surrounding the central region a.

The planarization by chemical mechanical polishing is performed on the upper surface of the inorganic material layer 14, so as to provide a flat surface for subsequent device fabrication.

Thereafter, step S5 is performed, and referring to fig. 9, O L ED light emitting devices 16 are formed in the central region a of the upper surface of the planarized inorganic material layer 14.

In an alternative, the O L ED light emitting device 16 includes an array pixel circuit including a plurality of thin film transistors such as a switching transistor and a driving transistor, and a pixel, the thin film transistors including a semiconductor active layer including a source region and a drain region formed by doping N-type impurity ions or P-type impurity ions and an undoped channel region between the source region and the drain region in a direction sequentially away from the upper surface of the solid flexible substrate 11, a gate insulating layer, a gate electrode, an interlayer insulating layer, a source electrode and a drain electrode on the semiconductor active layer, the source electrode and the drain electrode electrically connecting the source region and the drain region in the semiconductor active layer through contact holes in the interlayer insulating layer and the gate insulating layer, respectively, and an O L ED pixel including a pixel electrode serving as an anode, a pixel defining layer, an organic light emitting layer, and a common electrode serving as a cathode in a direction sequentially away from the solid flexible substrate 11, wherein the pixel electrode and the drain electrode are electrically connected, and the pixel electrode and the drain electrode further have a passivation layer therebetween.

The array pixel circuit and the O L ED pixel can also be fabricated by conventional methods for fabricating an array pixel light-emitting unit, which is not limited by the invention.

Thereafter, step S6 is performed, and referring to fig. 1, an encapsulation layer 17 is formed on the inorganic material layer 14 of the edge region B and the O L ED light emitting device 16 of the central region a.

The encapsulation layer 17 may include a three-layer structure of an inorganic layer, an organic layer, and an inorganic layer. The two inorganic layers can be formed by physical vapor deposition and chemical vapor deposition, and the middle organic layer can be formed by organic evaporation. The encapsulation layer 17 may also be an organic or inorganic multilayer spacer lamination structure, which is not limited by the present invention.

In other embodiments, after the encapsulation layer 17 is fabricated, the fabrication of the touch layer thereon may be continued to form a flexible O L ED touch panel.

Fig. 10 is a schematic structural diagram of a flexible O L ED display panel according to still another embodiment of the present invention.

Referring to fig. 1, the flexible O L ED display panel 3 includes:

a solid flexible substrate 31;

an inorganic material layer 32 on the solid flexible substrate 31, an upper surface of the inorganic material layer 32 including a central region a and an edge region B surrounding the central region a;

an O L ED light emitting device 33 located in a central region a of the upper surface of the inorganic material layer 32;

the encapsulation layer 34 is positioned on the inorganic material layer 32 of the edge region B and the O L ED light emitting device 33 of the central region A, and the encapsulation layer 34 comprises a first inorganic material encapsulation layer 341, an organic soft layer 342 and a second inorganic material encapsulation layer 343 from bottom to top;

wherein: the first inorganic material encapsulation layer 341 has a plurality of third deep grooves 3411;

the organic soft layer 342 covers the bottom wall and the side wall of the third deep groove 3411 and the first inorganic material encapsulation layer 341 outside the third deep groove 3411; the organic soft layer 342 does not fill the third deep groove 3411; the third deep groove 3411 covered with the organic soft layer 342 becomes the fourth deep groove 35;

the second inorganic material encapsulation layer 343 seals the fourth deep recess 35, forming a second air gap 36 within the fourth deep recess 35.

Specifically, the material of the solid flexible substrate 31 may be a conventional solid flexible substrate material such as polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone, or polyetherimide.

The material of the inorganic material layer 32 may be at least one of silicon nitride, silicon oxynitride, and silicon oxide. When the silicon nitride or the silicon oxynitride is used, the silicon nitride or the silicon oxynitride can be used as a passivation layer to prevent water vapor and oxygen from diffusing upwards from the solid flexible substrate 31. When silicon oxide is used, the silicon oxide can be used as an adhesion layer to improve the adhesion between the solid flexible substrate 31 and the inorganic material on the solid flexible substrate, and prevent peeling.

An alternative to the O L ED light emitting device 33 may include an array pixel circuit including a plurality of Thin Film Transistors (TFTs), such as a switching transistor and a driving transistor, and an O L ED pixel, in which a drain of the driving transistor is connected to a pixel electrode of the O L ED pixel, which serves as an anode, for injecting holes, and a cathode of the O L ED pixel is served by a common electrode, and the array pixel circuit and the O L ED pixel operate such that a gate of the switching transistor is electrically connected to a gate line, a source of the switching transistor is connected to a data line, the switching transistor is turned on and supplies an electric signal in the data line to the driving transistor when a scan signal of the gate line is active, the driving transistor is turned on and supplies an electric signal in a power supply voltage signal to the anode of the O L ED pixel, a potential difference is formed between the anode and the cathode, and electrons of the holes of the anode and electrons of the cathode are combined to emit light in an organic light emitting layer, thereby achieving a.

The first inorganic material sealing layer 341 and the second inorganic material sealing layer 343 of the sealing layer 34 may be made of silicon nitride to improve the performance of isolating external moisture and oxygen from entering the O L ED pixels.

The third deep groove 3411 in the first inorganic material encapsulation layer 341 does not penetrate through the first inorganic material encapsulation layer 341. The aspect ratio of the third deep groove 3411 is preferably greater than 5:1, e.g. 10: 1.

the third deep groove 3411 may be a hole or a groove, a cross-sectional structure of the hole is not limited, and an extending direction of the groove should be perpendicular to a curling direction of the flexible O L ED display panel 3.

The material of the organic soft layer 342 may be polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone, or polyetherimide. The material has good flexibility and good buffering performance.

When the second inorganic material encapsulation layer 343 is deposited on the organic soft layer 342, since the reactant molecules for generating the inorganic material are larger, the fourth deep groove 35 is easily sealed when the second inorganic material encapsulation layer 343 is not deposited in the fourth deep groove 35, or the deposition amount of the second inorganic material encapsulation layer 343 is small. A second air gap 36 is formed in the sealed fourth deep groove 35.

The organic and inorganic alternately stacked structure of the first inorganic material encapsulation layer 341, the organic soft layer 342, and the second inorganic material encapsulation layer 343 may be provided in multiple layers, and an air gap is formed between the inorganic material of at least one layer and the organic material thereon.

In the flexible O L ED display panel 3, the rugged structure of the third deep grooves 3411 in the first inorganic material sealing layer 341 is used to make the organic soft layer 342 in a rugged shape, and the second air gap 36 is formed between the organic soft layer 342 and the second inorganic material sealing layer 343 above the organic soft layer 342. the advantages are that the organic soft layer 342 has good tensile property relative to the inorganic material, can buffer the stress during the bending process of the O L ED display panel 3, can relieve the fracture of the inorganic stress layer and the peeling of the O L ED pixel function layer, and the second air gap 36 provides a space for accommodating the tensile or compressive strain of the soft material layer 342, so that the stress transfer between the layers is not caused.

The flexible O L ED display panel 3 can be used as a display device, and can be further provided with a touch layer on the packaging layer 34 to serve as a touch panel, the flexible O L ED display panel 3 can also be used as a semi-finished product to be integrated with other components and assembled together to form a display device such as a mobile phone, a tablet computer, a vehicle-mounted display screen, and the like, and it can be understood that the rugged organic soft layer 342 and the second air gap 36 are closer to the touch layer than the solid flexible substrate 31, so that the stress buffering effect during the curling process of the touch layer is better, and the touch layer can be prevented from being peeled off.

Fig. 11 is a schematic structural diagram of a flexible O L ED display panel according to still another embodiment of the present invention, referring to fig. 11, a flexible O L ED display panel 3' in this embodiment has substantially the same structure as the flexible O L ED display panel 3 in fig. 10, except that the third deep groove 3411' has a large opening and a small bottom, in other words, 1) the sidewalls of the third deep groove 3411' are tapered, and 2) the sidewalls of the third deep groove 3411' and the upper surface of the first inorganic material encapsulation layer 341 outside the third deep groove 3411' have an obtuse angle therebetween.

For the flexible O L ED display panel 3, 3' described above, the present invention also provides a manufacturing method, fig. 12 is a manufacturing flow chart in an embodiment, and fig. 13 to 15 are intermediate structure diagrams.

The following describes each manufacturing step in detail with reference to fig. 12 to 15.

First, with reference to fig. 12 and 13, step S1 is performed to provide the solid flexible substrate 31.

The material of the solid flexible substrate 31 may be polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone or polyetherimide.

Next, still referring to fig. 13, step S2 is performed to form an inorganic material layer 32 on the solid flexible substrate 31, wherein an upper surface of the inorganic material layer 32 includes a central region a and an edge region B surrounding the central region a.

The inorganic material layer 14 is made of silicon nitride, silicon oxide, or silicon oxynitride, and the corresponding deposition method is chemical vapor deposition.

Next, with continued reference to fig. 13, step S3 is performed to form an O L ED light emitting device 33 in the central region a of the upper surface of the inorganic material layer 32.

In an alternative, the O L ED light emitting device 33 includes an array pixel circuit including a plurality of thin film transistors such as a switching transistor and a driving transistor in a direction sequentially away from the upper surface of the solid flexible substrate 31, including a semiconductor active layer including a source region and a drain region formed by doping N-type impurity ions or P-type impurity ions therein and an undoped channel region between the source region and the drain region, a gate insulating layer, a gate electrode, an interlayer insulating layer, a source electrode and a drain electrode on the semiconductor active layer, the source electrode and the drain electrode electrically connecting the source region and the drain region in the semiconductor active layer through contact holes in the interlayer insulating layer and the gate insulating layer, respectively, and an O L ED pixel sequentially including a pixel electrode serving as an anode, a pixel defining layer, an organic light emitting layer, and a common electrode serving as a cathode in a direction sequentially away from the solid flexible substrate 11, wherein the pixel electrode is electrically connected to the drain electrode, and the pixel electrode further has a passivation layer therebetween.

Thereafter, referring to fig. 14 and 15, step S4 is performed to form an encapsulation layer 34 on the inorganic material layer in the edge region B and the O L ED light emitting device 33 in the central region a.

The present step S4 specifically includes the following steps S41-S43.

Step S41 is performed, referring to fig. 14, a first inorganic material encapsulation layer 341 is deposited on the inorganic material layer 32 in the edge region B and the O L ED light emitting device 33 in the central region a, and a plurality of third deep grooves 3411 are formed in the first inorganic material encapsulation layer 341.

The first inorganic material encapsulation layer 341 may be silicon nitride, silicon oxide, or silicon oxynitride, and the corresponding deposition method may be physical vapor deposition, chemical vapor deposition, or plasma enhanced chemical vapor deposition.

A plurality of third deep recesses 3411 are formed in the first inorganic material encapsulation layer 341 by photolithography and dry etching.

During the dry etching of the third deep groove 3411, the time of exposure of the opening to the etching plasma is longer than that of the bottom wall, so that the etched third deep groove 3411 has a slightly larger opening and a smaller bottom.

In an alternative, the third deep groove 3411 may be further etched by reducing a bias voltage between a stage carrying the member to be etched and the etching plasma generating apparatus, i.e., changing a unidirectionality of the plasma, to enlarge the opening, thereby forming a third deep groove 3411' as shown in fig. 11.

Step S42 is executed, referring to fig. 15, the first inorganic material encapsulation layer 32 covers the organic soft layer 342 at the bottom wall and the side wall of the third deep groove 3411 and outside the third deep groove 3411; the organic soft layer 342 does not fill the third deep groove 3411; the third deep groove 3411 covered with the organic soft layer 342 becomes the fourth deep groove 35.

In one embodiment, the covering of the organic soft layer 342 may be achieved by spin coating liquid polyimide, polyethylene naphthalate, polyethylene terephthalate, polyarylate, polycarbonate, polyethersulfone, or polyetherimide, and heating and curing. Spin coating is a technique that utilizes a high speed spin to spin off the film, which can be thin.

In another embodiment, the organic soft layer 342 may be covered by vapor deposition of the organic material.

The organic soft layer 342 is thinner, and does not fill the third deep groove 3411, and the aspect ratio of the third deep groove 3411 is not greatly reduced, so that the aspect ratio of the fourth deep groove 35 is substantially the same as that of the third deep groove 3411.

Step S43 is executed, referring to fig. 10, a second inorganic material encapsulation layer 343 is deposited on the organic soft layer 342, the second inorganic material encapsulation layer 343 is deposited to seal the fourth deep groove 35, and a second air gap 36 is formed in the fourth deep groove 35.

The second inorganic material encapsulant layer 343 may be made of silicon nitride, silicon oxide, or silicon oxynitride, and the corresponding deposition method is physical vapor deposition, chemical vapor deposition, or plasma enhanced chemical vapor deposition. The above processes are carried out in a reaction chamber. For example, for the chemical vapor deposition method, the molecules of the chemical reactant reacting to form the inorganic material are large, and the reactant can be deposited at the opening of the fourth deep groove 35 by reducing the vacuum pumping force applied to the reaction chamber.

After the step S43 is completed, the second inorganic material encapsulation layer 343 may be subjected to or not subjected to a chemical mechanical polishing process, and then the steps S41 to S43 are repeated at least once to form a multi-layer inorganic/organic stacked structure, wherein an air gap is formed between each layer of organic material and the inorganic material thereon. Of course, for the above-described multilayer inorganic-organic stack structure, it is also possible to have air gaps between the organic material of a partial layer and the inorganic material thereon.

In addition, after the encapsulation layer 34 is fabricated, the topmost second inorganic material encapsulation layer 343 may be subjected to chemical mechanical polishing, and then a touch layer is fabricated thereon, so as to form a flexible O L ED touch panel.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A flexible O L ED display panel, comprising:

a solid flexible substrate having a plurality of first deep grooves;

2. The flexible O L ED display panel of claim 1, wherein the solid flexible substrate comprises a first sublayer and a second sublayer stacked from bottom to top, the first deep groove being located in the second sublayer.

3. The flexible O L ED display panel of claim 1 or 2, wherein the first and second deep grooves are holes or grooves.

4. A flexible O L ED display panel according to claim 1 or 2, wherein the aspect ratio of the second deep groove is larger than 5: 1.

5. A display device comprising the flexible O L ED display panel of any one of claims 1 to 4.

6. A method for manufacturing a flexible O L ED display panel is characterized by comprising the following steps:

7. A flexible O L ED display panel, comprising:

a solid flexible substrate;

the method is characterized in that: the first inorganic material packaging layer is provided with a plurality of third deep grooves;

8. The flexible O L ED display panel of claim 7, wherein the third and fourth deep grooves are holes or grooves.

9. The flexible O L ED display panel of claim 7, wherein the third deep groove has a large opening and a small bottom.

10. The flexible O L ED display panel of claim 7, wherein the fourth deep groove has an aspect ratio greater than 5: 1.

11. A display device comprising the flexible O L ED display panel of any one of claims 7 to 10.

12. A manufacturing method of a flexible O L ED display panel comprises the following steps:

providing a solid flexible substrate;

wherein forming the encapsulation layer comprises: