CN114171703A

CN114171703A - Display panel, display device and manufacturing method of display panel

Info

Publication number: CN114171703A
Application number: CN202111480314.2A
Authority: CN
Inventors: 潘洪英; 覃事建
Original assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Shenzhen China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2021-12-06
Filing date: 2021-12-06
Publication date: 2022-03-11
Anticipated expiration: 2041-12-06
Also published as: CN114171703B

Abstract

The application provides a display panel, a display device and a manufacturing method of the display panel, wherein the display panel sequentially comprises a flexible substrate layer, a display layer and a packaging layer from bottom to top, and the positions of the flexible substrate layer, corresponding to a leveling area and a bending area, are respectively defined as a leveling part and a bending part; one side that the encapsulation layer was kept away from to the kink is equipped with at least one recess, and the thickness direction on flexible base plate layer is followed to the recess extends, is equipped with waterproof glue in the recess. The display panel provided by the embodiment of the application reduces the stress of the bending area and improves the stability and the reliability of the bending area, so that the bending area is not easy to crack or break, and the quality of the display panel is ensured.

Description

Display panel, display device and manufacturing method of display panel

Technical Field

The application belongs to the technical field of display, and particularly relates to a display panel, a display device and a manufacturing method of the display panel.

Background

Organic Light Emitting Diodes (OLEDs) have potential market prospects that are promising for the industry due to their advantages of self-luminescence, fast response, wide viewing angle, high brightness, thinness, and the like. The conventional display panel is usually made bendable by adopting OLED display technology in combination with flexible substrate technology. However, in the related art, since the flexible substrate is too simple in structural design, a large stress is applied to the bending region of the display panel, so that the bending region of the display panel is easily cracked or broken.

Disclosure of Invention

The embodiment of the application provides a display panel, a display device and a manufacturing method of the display panel, and aims to solve the problem that a bending area of an existing display panel is prone to cracking or breaking.

In a first aspect, an embodiment of the present application provides a display panel, which includes a leveling area and a bending area located at an edge of the leveling area, where the display panel sequentially includes a flexible substrate layer, a display layer, and an encapsulation layer from bottom to top, and is characterized in that positions of the flexible substrate layer corresponding to the leveling area and the bending area are respectively defined as a leveling portion and a bending portion;

one side that the kink was kept away from the encapsulation layer is equipped with at least one recess, the recess is followed the thickness direction on flexible base plate layer extends, be equipped with waterproof glue in the recess.

Optionally, the depth of the groove is H, the thickness of the bending portion is H, and the ratio of H to H is 1:3 to 1: 2.

Optionally, the bending portion has a bending region, the curvature of the bending region is greater than the curvature of any other portion of the bending portion, and the groove is located in the bending region.

Optionally, two opposite groove walls of the groove abut against each other at the notch portion.

Optionally, the display panel further includes an EVA film layer, and the EVA film layer is disposed on a surface of the encapsulation layer deviating from the display layer.

Optionally, the content of vinyl acetate in the EVA film layer is 10% to 40%.

Optionally, the number of the EVA film layers is multiple, and the content of the vinyl acetate in the EVA film layers decreases layer by layer in the direction away from the encapsulation layer.

In a second aspect, embodiments of the present application further provide a display device, including the display panel according to any one of the above aspects.

In a third aspect, an embodiment of the present application further provides a method for manufacturing a display panel, including the following steps:

providing a flexible substrate, wherein the flexible substrate comprises a flat part and a part to be bent, and a groove is formed in the part to be bent;

disposing a display layer on the flexible substrate;

arranging an encapsulation layer on the display layer to form a panel to be bent;

dripping waterproof glue in the groove;

and bending the part of the panel to be bent, which corresponds to the part to be bent, towards the surface where the groove is located.

Optionally, after the step of bending the portion of the panel to be bent corresponding to the portion to be bent toward the surface where the groove is located, the method further includes: and carrying out ultraviolet curing on the waterproof glue.

Optionally, after the step of disposing an encapsulation layer on the display layer, the method further includes: and arranging an EVA film layer on the packaging layer.

Optionally, after the step of disposing the EVA film layer on the encapsulation layer, the method further includes: and thermally curing the EVA film layer.

Optionally, the step of providing a flexible substrate includes:

providing a base, arranging a stripping layer on the base, wherein the stripping layer is provided with a middle area and a side area, and a bulge is convexly arranged on the side area;

and arranging a flexible substrate on one surface of the stripping layer with the protrusions in a coating mode.

The display panel that this application embodiment provided is provided with the recess through the kink on flexible base plate layer, has reduced the holistic stress in kink district to the stability in kink district has been improved. Be equipped with waterproof glue in the recess, when waterproof oxygen-proof, can also fill the recess, stereotype the district of buckling, ensured the stability and the reliability in district of buckling to make the difficult crackle or fracture of producing in district of buckling, guaranteed display panel's quality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the application, and that other drawings can be derived from these drawings by a person skilled in the art without inventive effort.

For a more complete understanding of the present application and its advantages, reference is now made to the following descriptions taken in conjunction with the accompanying drawings. Wherein like reference numerals refer to like parts in the following description.

Fig. 1 is a schematic cross-sectional view of a display panel provided in an embodiment of the present application after bending.

Fig. 2 is an enlarged schematic structural diagram of a part a of the display panel shown in fig. 1.

FIG. 3 is a schematic cross-sectional view of a base and a release layer provided in an embodiment of the present application.

Fig. 4 is a schematic cross-sectional view of a base, a peeling layer, and a display panel provided in an embodiment of the present application.

FIG. 5 is a schematic cross-sectional view of a substrate, a peeling layer, and a display panel according to an embodiment of the present disclosure after separation.

Fig. 6 is a schematic cross-sectional view of a display panel provided in an embodiment of the present application before bending.

Fig. 7 is a schematic flowchart of a manufacturing method of a display panel according to an embodiment of the present application.

Fig. 8 is a flowchart illustrating an embodiment of step S10 in fig. 7.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides a display panel and a display device, which are used for solving the problem that the bending area 12 of the existing display panel is easy to crack or break. The following description will be made with reference to the accompanying drawings.

The display panel provided by the embodiment of the application can be applied to a display device, wherein the display device can be any product or component with a display function, such as electronic paper, a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator and the like.

In order to more clearly explain the structure of the display panel, the display panel will be described below with reference to the accompanying drawings.

For example, please refer to fig. 1, fig. 1 is a schematic cross-sectional view of a display panel provided in an embodiment of the present application after being bent. The display panel sequentially comprises a flexible substrate layer 100, a display layer 200 and an encapsulation layer 300 from bottom to top. Wherein, the positions of the flexible substrate layer 100 corresponding to the flat region 11 and the bending region 12 are respectively defined as a flat portion 110 and a bending portion 120; one side of the bending portion 120 away from the encapsulation layer 300 is provided with at least one groove 121, the groove 121 extends along the thickness direction of the flexible substrate layer 100, and a waterproof adhesive 122 is disposed in the groove 121. By providing the groove 121 at the bending portion 120 of the flexible substrate layer 100, the stress of the whole bending region 12 is reduced, thereby improving the stability of the bending region 12. Be equipped with waterproof glue 122 in the recess 121, when waterproof oxygen-proof, can also fill recess 121, stereotype bending region 12, ensured bending region 12's stability and reliability to make bending region 12 be difficult for producing crackle or fracture, guaranteed display panel's quality.

The flexible substrate layer 100 is made of a flexible material, such as a poly-p-phenylene-terephtalate plastic or polyimide, but not limited thereto. The display layer 200 may emit light, for example, in a direction in which the flexible substrate layer 100 points to the encapsulation layer 300, the display layer 200 may sequentially include an electron transport layer, an electron injection layer, an organic light emitting layer, a hole injection layer, a hole transport layer, and a cathode layer. It is understood that the encapsulation layer 300 is made of a light-transmitting material, such as tetrafluoroethylene resin, silicon dioxide, etc., and light emitted from the display layer 200 passes through the encapsulation layer 300 and exits the outside of the display panel.

The depth of the groove 121 should not be too large, which would make the whole thickness of the bending region 12 thinner, and is not favorable for ensuring the stability of the bending region 12, and should not be too small, and the too small is not favorable for reducing the stress of the bending region 12. For example, please refer to fig. 6, and fig. 6 is a schematic cross-sectional view of a display panel provided in an embodiment of the present application before bending. The depth of the groove 121 is H, the thickness of the bending portion 120 is H, and the ratio of H to H is 1:3 to 1: 2. Thus, the groove 121 ensures the stability of the bending region 12 while reducing the overall stress of the bending region 12, so that the bending region 12 is stable and reliable, the bending region 12 is not easy to crack or break, and the quality of the display panel is ensured.

In some examples, to improve the stability of the inflection zone 12, the opposing walls of the groove 121 abut each other at the notch portion. Thus, the inner structure of the bending part 120 of the flexible substrate layer 100 is stable and not easy to deform, and the groove wall of the groove 121 can stably support the display layer 200 and the encapsulation layer 300 on the flexible substrate layer 100, thereby improving the stability of the bending region 12 of the display panel.

In some examples, please refer to fig. 2 in combination with fig. 1, and fig. 2 is an enlarged structural diagram of a portion a of the display panel shown in fig. 1. The bending part 120 is provided with a bending area 123, the curvature of the bending area 123 is larger than that of any other part on the bending part 120, and the groove 121 is arranged in the bending area 123. It can be understood that, since the bent portion 120 is at the edge of the flat portion 110, the bent portion 120 is bent, and the flat portion 110 is kept flat, the curvature of the middle portion of the bent portion 120 is the largest in the area of the flat portion 110, and the larger the curvature, the more easily cracks or breaks. In this example, the groove 121 is disposed in other regions, and is kept away from the region with the largest curvature, so that the thickness of the region with the largest curvature in the bending region 12 is ensured while the whole stress of the bending region 12 is reduced by the groove 121, thereby ensuring the strength of the region, ensuring that the region is not easily broken, and ensuring the quality of the display panel.

In some examples, please refer to fig. 6 in combination with fig. 1, and fig. 6 is a schematic cross-sectional view of a display panel provided in an embodiment of the present application before bending. The display panel further comprises an EVA film layer, and the EVA film layer is arranged on the surface of the packaging layer 300 deviating from the display layer 200. The EVA film layer, that is, the ethylene-vinyl acetate copolymer film layer, has good water resistance, corrosion resistance, and the like, and can protect the encapsulation layer 300. Because the ethylene-vinyl acetate copolymer also has good filler inclusion and crosslinkability, in practical application, the EVA film can be subjected to thermosetting, the EVA generates a crosslinking effect, and microcracks generated on the packaging layer 300 are repaired, so that the quality of the display panel is improved.

Wherein, the content of the vinyl acetate in the EVA film layer is 10-40%. For example, it may be 15%, 20%, 25%, 30%, 35%, etc. It should be noted that the higher the content of vinyl acetate, the better the viscosity of the EVA film and the better the repairing effect, but at the same time, the lower the elasticity of the EVA film. The content of the vinyl acetate in the EVA film layer is controlled to be 10% -40%, and the EVA film layer is ensured to have good elasticity while good viscosity so as to have good repairing effect, so that the EVA film layer is prevented from being broken.

The quantity of EVA rete can be one deck, also can be the multilayer, and when being multilayer, in the direction of keeping away from encapsulated layer 300, the content successive layer of vinyl acetate reduces in the EVA rete. That is, the closer to the repair effect of the EVA film layer of the encapsulation layer 300, the better to effectively repair the encapsulation layer 300, and the farther away from the EVA film layer of the encapsulation layer 300, the better the elasticity, so as to prevent the EVA film from breaking, so as to ensure the stability of the EVA film layer. And the lower the content of the vinyl acetate is, the higher the transparency of the EVA film layer is, so as to ensure the effect of light emission.

Referring to fig. 7 and 8, fig. 7 is a schematic flow chart illustrating a manufacturing method of a display panel according to an embodiment of the present disclosure. Fig. 8 is a flowchart illustrating an embodiment of step S10 in fig. 7. The embodiment of the present application further provides a manufacturing method of a display panel, including the following steps:

s10, providing a flexible substrate, wherein the flexible substrate comprises a flat part 110 and a part to be bent 120, and the part to be bent 120 is provided with a groove 121;

s20, disposing the display layer 200 on the flexible substrate;

s30, arranging the packaging layer 300 on the display layer 200 to form a panel to be bent;

s40, dripping waterproof glue 122 in the groove 121;

and S50, bending the part of the panel to be bent corresponding to the part 120 to be bent towards the surface where the groove 121 is located.

In step S10, the flexible substrate is made of a flexible material, such as a poly-p-phenylene terephtalate plastic or polyimide, and the recess 121 may be formed in various ways, such as directly opening on the flat flexible substrate, or formed in other ways, for example, the step of providing a flexible substrate includes:

s11, providing a base 20, arranging a peeling layer 30 on the base 20, wherein the peeling layer 30 is provided with a middle area 31 and side areas 32, and bulges 33 are convexly arranged on the side areas 32;

s12, a flexible substrate is applied to the surface of the release layer 30 having the projections 33.

In step S11, referring to fig. 3, fig. 3 is a schematic cross-sectional view of the base 20 and the release layer 30 provided in the embodiment of the present application. The substrate 20 may be a glass substrate 20, and the material of the peeling layer 30 may be SiOx, SiNx, or a stack of SiOx and SiNx. SiOx can be silicon monoxide or silicon dioxide, and is not limited herein; SiNx may be Si3N4, i.e. silicon nitride. The peeling layer 30 may be deposited on the glass substrate by means of a chemical vapor deposition method, and then the protrusions 33 may be formed on the peeling layer 30 by means of etching.

In step S12, referring to fig. 4 and 5, fig. 4 is a schematic cross-sectional view of the base 20, the peeling layer 30, and the display panel according to the embodiment of the present application. Fig. 5 is a schematic cross-sectional view of the base 20, the peeling layer 30, and the display panel provided in the embodiment of the present application after separation. The flexible substrate may be manufactured on the side of the peeling layer 30 having the protrusions 33 by means of coating. Since the peeling layer 30 has the projections 33, the flexible substrate forms the grooves 121 corresponding to the positions of the projections 33 after the peeling layer 30 and the base 20 are removed. In actual manufacturing, the peeling layer 30 and the base 20 may be removed after the flexible substrate layer 100 is provided, or the peeling layer 30 and the base 20 may be removed after each layer of the display panel, such as the display layer 200 and the sealing layer 300, is provided.

In step S20, the display layer 200 may include an electron transport layer, an electron injection layer, an organic light emitting layer, a hole injection layer, a hole transport layer, and a cathode layer, which may be made of silver, magnesium, or the like. The display layer 200 may be disposed on the flexible substrate layer 100 by conventional techniques known in the art, such as evaporation techniques.

In step S30, the material of the encapsulation layer 300 may be tetrafluoroethylene resin, silicon dioxide, etc., and the encapsulation layer 300 may be manufactured by conventional methods such as chemical vapor deposition, etc., and is not limited in particular.

In some examples, after step S30, step S31 may also be performed: an EVA film layer is disposed on the encapsulation layer 300. The EVA film layer is also an ethylene-vinyl acetate copolymer film layer. When the EVA adhesive is set, the EVA adhesive is provided, and the content of the vinyl acetate in the EVA adhesive is 10% -40%, for example, 15%, 20%, 25%, 30%, 35% and the like. Then, the EVA glue is attached to the encapsulation layer 300 to form an EVA film layer, which can play a role in water and oxygen prevention to protect the encapsulation layer 300. In practical applications, step S32 may be further performed: and thermally curing the EVA film layer. Therefore, the EVA is subjected to a crosslinking effect, and microcracks generated on the packaging layer 300 are repaired, so that the quality of the display panel is improved.

In step S40, the waterproof glue 122 may be PP glue, PE glue, rubber glue, polyurethane glue, or the like. During dispensing, the dispensing amount can be reasonably controlled according to the bending angle of the bending area 12 and the size of the groove 121, so that after the bending area 12 is bent, the waterproof glue 122 cannot overflow the groove 121 to pollute the flexible substrate layer 100.

In step S50, the panel to be bent is bent according to the desired bending angle, so as to obtain a display panel having a flat region 11 and a bent region 12.

After step S50, step S60 may also be performed: the waterproof glue 122 is uv cured. Under the adhesive force of the waterproof adhesive 122, the bending area 12 is quickly shaped along with the solidification of the waterproof adhesive 122, and the stability and reliability of the bending area 12 are ensured.

In the foregoing embodiments, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In the description of the present application, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. The display panel provided by the embodiment of the present application is described in detail above, and the principle and the implementation of the present application are explained in this document by applying specific examples, and the description of the above embodiment is only used to help understanding the method and the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

Claims

1. A display panel comprises a leveling area and a bending area positioned at the edge of the leveling area, and the display panel sequentially comprises a flexible substrate layer, a display layer and an encapsulation layer from bottom to top;

2. The display panel according to claim 1, wherein the depth of the groove is H, the thickness of the bending portion is H, and the ratio of H to H is 1:3 to 1: 2.

3. The display panel according to claim 1, wherein the bending portion has a bending area, a curvature of the bending area is greater than a curvature of any other portion of the bending portion, and the groove is located in the bending area.

4. The display panel of claim 1, wherein the opposing walls of the groove abut each other at the notch portion.

5. The display panel of claim 1, further comprising an EVA film layer disposed on a surface of the encapsulation layer facing away from the display layer.

6. The display panel according to claim 5, wherein the EVA film layer contains 10-40% of vinyl acetate.

7. The display panel according to claim 6, wherein the number of the EVA film layers is multiple, and the content of the vinyl acetate in the EVA film layers decreases layer by layer in a direction away from the encapsulation layer.

8. A display device characterized by comprising the display panel according to any one of claims 1 to 7.

9. A manufacturing method of a display panel is characterized by comprising the following steps:

disposing a display layer on the flexible substrate;

dripping waterproof glue in the groove;

10. The method for manufacturing a display panel according to claim 9, wherein after the step of bending the portion of the panel to be bent corresponding to the portion to be bent toward the surface where the groove is located, the method further comprises: and carrying out ultraviolet curing on the waterproof glue.

11. The method for manufacturing a display panel according to claim 9, further comprising, after the step of disposing an encapsulation layer on the display layer: and arranging an EVA film layer on the packaging layer.

12. The method for manufacturing a display panel according to claim 11, further comprising, after the step of disposing an EVA film layer on the encapsulation layer: and thermally curing the EVA film layer.

13. The method of claim 9, wherein the step of providing a flexible substrate comprises: