CN114171703B

CN114171703B - Display panel, display device and manufacturing method of display panel

Info

Publication number: CN114171703B
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: 2023-10-17
Anticipated expiration: 2041-12-06
Also published as: CN114171703A

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 of the bending part far away from the packaging layer is provided with at least one groove, the groove extends along the thickness direction of the flexible substrate layer, and waterproof glue is arranged in the groove. The display panel provided by the embodiment of the application reduces the stress of the bending region and improves the stability and the reliability of the bending region, so that the bending region 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

The Organic Light Emitting Diode (OLED) has the advantages of self-luminescence, fast response, wide viewing angle, high brightness, light weight, and the like, and thus has a potential market prospect seen by the industry. In the existing display panel, the OLED display technology is generally adopted in combination with the technology of the flexible substrate, so that the display panel can be bent. However, in the related art, because the structural design of the flexible substrate is too simple, a large stress exists in the bending region of the display panel, so that the bending region of the display panel is easy to crack or break.

Disclosure of Invention

The embodiment of the application provides a display panel, a display device and a manufacturing method of the display panel, which are used for solving the problem that a bending area of the existing display panel is easy to crack or break.

In a first aspect, an embodiment of the present application provides a display panel, including a flat area and a bending area located at an edge of the flat area, where the display panel includes, in order from bottom to top, a flexible substrate layer, a display layer, and a packaging layer, where positions of the flexible substrate layer corresponding to the flat area and the bending area are defined as a flat portion and a bending portion, respectively;

one side of the bending part far away from the packaging layer is provided with at least one groove, the groove extends along the thickness direction of the flexible substrate layer, and waterproof glue is arranged in the groove.

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

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

Optionally, two opposite groove walls of the groove are abutted against each other at a part of the notch.

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

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

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

In a second aspect, an embodiment of the present application further provides a display device, including a display panel according to any one of the above.

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 the part to be bent is provided with a groove;

a display layer is arranged on the flexible substrate;

arranging a packaging 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 corresponding 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 an EVA film layer is arranged on the packaging layer.

Optionally, after the step of disposing an 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, and 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 arranged in the side area in a protruding mode;

a flexible substrate is provided by coating on the side of the release layer having the protrusions.

According to the display panel provided by the embodiment of the application, the grooves are formed in the bending part of the flexible substrate layer, so that the integral stress of the bending area is reduced, and the stability of the bending area is improved. The waterproof glue is arranged in the groove, the groove can be filled while the waterproof glue is used for preventing oxygen, the bending area is shaped, the stability and the reliability of the bending area are ensured, and therefore cracks or fractures are not easy to generate in the bending area, and the quality of the display panel is ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that are required to be used in the description of the embodiments will be briefly described below. It is evident that the figures in the following description are only some embodiments of the application, from which other figures can be obtained without inventive effort for a person skilled in the art.

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

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

Fig. 2 is an enlarged schematic view of a portion 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 by an embodiment of the present application.

FIG. 4 is a schematic cross-sectional view of a substrate, a peeling layer and a display panel according to an embodiment of the present application.

Fig. 5 is a schematic cross-sectional view of a separated substrate, a separated release layer and a display panel according to an embodiment of the present application.

Fig. 6 is a schematic cross-sectional view of a display panel before bending according to an embodiment of the application.

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

Fig. 8 is a flowchart of 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 accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to fall within the scope of the application.

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

For example, referring to fig. 1, fig. 1 is a schematic cross-sectional view of a display panel after bending according to an embodiment of the application. The display panel includes, in order from bottom to top, a flexible substrate layer 100, a display layer 200, and an encapsulation layer 300. Wherein, the positions of the flexible substrate layer 100 corresponding to the flat region 11 and the bending region 12 are defined as a flat portion 110 and a bending portion 120, respectively; at least one groove 121 is formed in one side of the bending portion 120 away from the packaging layer 300, the groove 121 extends along the thickness direction of the flexible substrate layer 100, and waterproof glue 122 is arranged in the groove 121. By providing the recess 121 at the inflection 120 of the flexible substrate layer 100, the stress of the inflection region 12 as a whole is reduced, thereby improving the stability of the inflection region 12. The waterproof glue 122 is arranged in the groove 121, the groove 121 can be filled while water and oxygen are prevented, the bending area 12 is shaped, and the stability and the reliability of the bending area 12 are ensured, so that the bending area 12 is not easy to crack or break, and the quality of the display panel is ensured.

The flexible substrate layer 100 is made of a flexible material, such as a polyethylene terephthalate plastic, a polyimide, or the like, which is not limited herein. The display layer 200 may emit light, for example, in a direction in which the flexible substrate layer 100 is directed toward the encapsulation layer 300, 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 in this order. It will be appreciated that the encapsulation layer 300 may be made of a light-transmitting material, such as tetrafluoroethylene resin, silicon dioxide, etc., and the light emitted from the display layer 200 may be emitted outside the display panel through the encapsulation layer 300.

The depth of the groove 121 should not be too large, which makes the overall thickness of the bending region 12 thinner, which is not beneficial to ensuring the stability of the bending region 12, or too small, which is not beneficial to reducing the stress of the bending region 12. Fig. 6 is a schematic cross-sectional view of a display panel before bending according to an embodiment of the application. 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. In this way, the groove 121 reduces the stress of the whole bending region 12, and ensures the stability of the bending region 12, so that the bending region 12 is stable and reliable, and the bending region 12 is not easy to crack or break, thereby ensuring the quality of the display panel.

In some examples, to improve stability of inflection zone 12, opposing walls of groove 121 abut each other at portions of the slot. In this way, the inner structure of the bending portion 120 of the flexible substrate layer 100 is stable and not easy to deform, and the wall of the groove 121 can stably support the display layer 200 and the packaging layer 300 on the flexible substrate layer 100, so that the stability of the bending region 12 of the display panel is improved.

In some examples, please refer to fig. 2 in conjunction with fig. 1, fig. 2 is an enlarged schematic view of a portion a of the display panel shown in fig. 1. The bending portion 120 has a bending region 123, the curvature of the bending region 123 is greater than the curvature of any other portion of the bending portion 120, and the groove 121 is located in the bending region 123. It can be understood that, since the bending portion 120 is formed at the edge of the flat portion 110, in the case where the bending portion 120 is bent and the flat portion 110 is kept flat, the curvature of the area of the middle portion of the bending portion 120, which deflects the flat portion 110, is the largest, and the larger the curvature, the more easily cracks or breaks. In this example, the groove 121 is disposed in other regions, but is not disposed in 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 overall stress of the bending region 12 is reduced by the groove 121, thereby ensuring the strength of the region, ensuring the quality of the display panel, and ensuring the breakage resistance of the region.

In some examples, please refer to fig. 1 and fig. 6, fig. 6 is a schematic cross-sectional view of a display panel before bending according to an embodiment of the present application. The display panel further includes an EVA film layer disposed on a surface of the encapsulation layer 300 facing away from the display layer 200. The EVA film, i.e., the ethylene-vinyl acetate copolymer film, has good water resistance, corrosion resistance, etc., and can protect the encapsulation layer 300. Because the ethylene-vinyl acetate copolymer also has good filler inclusion and cross-linking property, the EVA film can be thermally cured and the EVA is cross-linked in practical application, and microcracks generated on the packaging layer 300 are repaired, so that the quality of the display panel is improved.

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

The number of EVA layers may be one or more, and when the number of EVA layers is multiple, the vinyl acetate content in the EVA layers decreases from layer to layer in a direction away from the encapsulation layer 300. That is, the repair effect of the EVA film layer closer to the encapsulation layer 300 is better to repair the encapsulation layer 300 effectively, and the elasticity of the EVA film layer further from the encapsulation layer 300 is better to prevent the EVA film from breaking, so as to ensure the stability of the EVA film layer. In addition, the lower the content of the vinyl acetate, the higher the transparency of the EVA film layer, so as to ensure the light emitting effect.

Referring to fig. 7 and 8, fig. 7 is a flowchart illustrating a method for manufacturing a display panel according to an embodiment of the application. Fig. 8 is a flowchart of an embodiment of step S10 in fig. 7. The embodiment of the application also provides a manufacturing method of the display panel, which comprises the following steps:

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

s20, arranging a display layer 200 on a flexible substrate;

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

s40, dripping waterproof glue 122 in the groove 121;

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, for example, a polyethylene terephthalate plastic or polyimide, and the grooves 121 may be formed in various manners, or may be directly formed on a flat flexible substrate, or may be formed in other manners, and the step of providing a flexible substrate includes:

s11, providing a base 20, arranging a stripping layer 30 on the base 20, wherein the stripping layer 30 is provided with a middle area 31 and a side area 32, and a protrusion 33 is arranged on the side area 32 in a protruding mode;

s12, a flexible substrate is provided by coating on the surface of the release layer 30 having the protrusions 33.

In step S11, referring to fig. 3, fig. 3 is a schematic cross-sectional view of the base 20 and the peeling layer 30 according to the embodiment of the present application. The base 20 may be a glass base 20, and the material of the peeling layer 30 may be SiOx, siNx, or a laminate of SiOx and SiNx. SiOx may be silicon monoxide or silicon dioxide, without limitation; siNx may be Si3N4, i.e., silicon nitride. The peeling layer 30 may be deposited on the glass substrate by a chemical vapor deposition method, and then the protrusions 33 may be formed on the peeling layer 30 by 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 application. Fig. 5 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 after separation. The flexible substrate may be manufactured by coating on the side of the peeling layer 30 having the protrusions 33. Since the peeling layer 30 has the protrusions 33, the grooves 121 are formed at positions of the flexible substrate corresponding to the protrusions 33 after the peeling layer 30 and the base 20 are removed. In actual manufacturing, after the flexible substrate layer 100 is provided, the release layer 30 and the base 20 may be removed, or the layers of the display panel, such as the display layer 200 and the encapsulation layer 300, may be provided, and the release layer 30 and the base 20 may be removed.

In step S20, 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, and the material of the cathode layer may be silver, magnesium, or the like. The display layer 200 may be disposed on the flexible substrate layer 100 by a conventional technique such as an evaporation technique.

In step S30, the material of the encapsulation layer 300 may be tetrafluoroethylene resin, silicon dioxide, etc., and the method for manufacturing the encapsulation layer 300 may be a conventional method such as chemical vapor deposition, etc., which is not particularly limited herein.

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 an ethylene-vinyl acetate copolymer film layer. In the setting, the EVA adhesive is provided first, and the content of vinyl acetate in the EVA adhesive is 10% -40%, for example, 15%, 20%, 25%, 30%, 35% and the like. Then, the EVA adhesive is attached to the packaging layer 300 to form an EVA film layer, which can play a role in water and oxygen prevention so as to protect the packaging layer 300. In practical application, step S32 may also be performed: and (5) thermally curing the EVA film layer. In this way, the EVA is crosslinked, and the microcracks generated on the encapsulation layer 300 are repaired, thereby improving the quality of the display panel.

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

In step S50, when the display panel is folded, the panel to be folded is folded according to the desired folding angle, so as to obtain the display panel having the flat area 11 and the folding area 12.

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

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

In the description of the present application, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features. The display panel provided by the embodiment of the present application has been described in detail, and specific examples are applied to illustrate the principles and embodiments of the present application, and the description of the above embodiments is only for helping to understand the method and core idea of the present application; meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the ideas of the present application, the present description should not be construed as limiting the present application in summary.

Claims

1. The display panel comprises a leveling region and a bending region positioned at the edge of the leveling region, and sequentially comprises a flexible substrate layer, a display layer and a packaging layer from bottom to top, and is characterized in that the positions of the flexible substrate layer corresponding to the leveling region and the bending region are respectively defined as a leveling part and a bending part;

at least one groove is formed in one side, far away from the packaging layer, of the bending part, the groove extends along the thickness direction of the flexible substrate layer, and waterproof glue is arranged in the groove;

the bending part is provided with a bending area, the curvature of the bending area is larger than that of any other part of the bending part, and the groove is located in the bending area; the two opposite groove walls of the groove are mutually abutted at the parts of the groove opening, the display panel further comprises an EVA film layer, the EVA film layer is arranged on the surface of the packaging layer, which is away from the display layer, the content of vinyl acetate in the EVA film layer is 10% -40%, the number of the EVA film layers is multiple, and in the direction away from the packaging layer, the content of vinyl acetate in the EVA film layer is reduced layer by layer.

2. The display panel of 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. A display device comprising the display panel according to any one of claims 1 to 2.

4. The manufacturing method of the display panel is characterized by comprising the following steps:

a display layer is arranged on the flexible substrate;

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

dripping waterproof glue in the groove;

bending the part of the panel to be bent corresponding to the part to be bent towards the surface where the groove is located;

the bending part is provided with a bending area, the curvature of the bending area is larger than that of any other part of the bending part, and the groove is located in the bending area; the two opposite cell walls of recess are at the mutual butt of the part of notch, and display panel still includes the EVA rete, and the surface that the encapsulation layer deviates from the display layer is located to the EVA rete, the content of vinyl acetate is 10% -40% in the EVA rete, the quantity of EVA rete is the multilayer, in keeping away from in the direction of encapsulation layer, the content of vinyl acetate reduces layer by layer in the EVA rete, carries out the thermosetting to the EVA rete, and the EVA rete takes place the crosslinking, is right microcrack that produces on the encapsulation layer is restoreed.

5. The method for manufacturing a display panel according to claim 4, 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.

6. The method of claim 4, wherein the step of providing a flexible substrate comprises: